Publications

© 2021. The Author(s).

Keywords: ACL; Psychosocial factors; Quadriceps; knee.

Keywords: autografts; knee; reconstructive surgical procedures.

Keywords: Anterior cruciate ligament reconstruction; Knee; Quadriceps tendon autograft.

Keywords: Anterior cruciate ligament; Hamstring; Isokinetic strength; Jump-landing; Quadriceps; Side direction.

Keywords: Anterior cruciate ligament reconstruction; Arthroscopy; Hamstring tendons; Magnetic resonance imaging; Patellar ligament.

Keywords: ACL surgery; Anticoagulants; Deep venous thromboembolism; Pulmonary embolism.

Keywords: ACL reconstruction; Hamstring tendon; Knee; Quadriceps tendon.

Purpose: The purpose of this study was to evaluate sports activity before anterior cruciate ligament (ACL) injury and after surgical treatment of ACL rupture comparing ACL repair with an Internal Brace to ACL reconstruction using either a hamstring (HT) or quadriceps tendon (QT) autograft.

Methods: Between 12/2015 and 10/2016, we recruited 69 patients with a mean age of 33.4 years for a matched-pair analysis. Twenty-four patients who underwent Internal Brace reconstruction were matched according to age (± 5 years), gender, Tegner activity scale (± 1), BMI (± 1) and concomitant injuries with 25 patients who had undergone HT reconstruction and 20 patients who had undergone QT reconstruction. The minimum follow-up was 12 months.

Results: Overall, the return-to-sports rate was 91.3 %. There were no significant differences (p ≥ 0.05) in the number of sports disciplines and the time before return to sports within or among the groups. Overall and within the groups, the level of sports participation did not change significantly (p ≥ 0.05) postoperatively. The patients’ sense of well-being was excellent after either ACL repair with an Internal Brace or ACL reconstruction with autologous HT or QT.

Conclusion: At short-term follow-up, ACL repair using an Internal Brace enables sports activity and provides a sense of well-being similar to that of classic ACL reconstruction using hamstring or quadriceps tendon autografts in a selected patient population.

Level of evidence: Level III Retrospective comparative study.

Keywords: ACL reconstruction; Graft size measurement; MRI; Preoperative planning; Quadriceps tendon autograft.

Background: Multiligament knee injuries, though rare, can be profoundly disabling. Surgeons disagree about when to initiate rehabilitation after surgical reconstruction due to the conflicting priorities of postoperative stability and motion.

Questions/purposes: (1) Does early or late initiation of physical therapy after multiligament knee surgery result in fewer postoperative manipulations? (2) Does early versus late physical therapy compromise stability postoperatively? (3) Does early initiation of physical therapy result in improved patient-reported outcomes, as measured by the Multi-ligament Quality of Life (ML-QOL) score?

Methods: Between 2011 and 2016, 36 adults undergoing multiligament repair or reconstruction were prospectively enrolled in a randomized controlled trial and randomized 1:1 to either early rehabilitation or late rehabilitation after surgery. Eligibility included those with an injury to the posterior cruciate ligament (PCL) and at least one other ligament, as well as the ability to participate in early rehabilitation. Patients who were obtunded or unable to adhere to the protocols for other reasons were excluded. Early rehabilitation consisted of initiating a standardized physical therapy protocol on postoperative day 1 involving removal of the extension splint for quadriceps activation and ROM exercises. Late rehabilitation consisted of full-time immobilization in an extension splint for 3 weeks. Following this 3-week period, both groups engaged in the same standardized physical therapy protocol. All surgical reconstructions were performed at a single center by one of two fellowship-trained sports orthopaedic surgeons, and all involved allograft Achilles tendon PCL reconstruction. When possible, hamstring autograft was used for ACL and medial collateral ligament reconstructions, whereas lateral collateral ligament and posterolateral reconstruction was performed primarily with allograft. The primary outcome was the number of patients undergoing manipulation during the first 6 months. Additional outcomes added after trial registration were patient-reported quality of life scores (ML-QOL) at 1 year and an objective assessment of laxity through a physical examination and stress radiographs at 1 year. One patient from each group was not assessed for laxity or ROM at 1 year, and one patient from each group did not complete the ML-QOL questionnaires. No patient crossover was observed.

Results: With the numbers available, there was no difference in the use of knee manipulation during the first 6 months between the rehabilitation groups: 1 of 18 patients in the early group and 4 of 18 patients in the late group (p = 0.34). Similarly, there were no differences in knee ROM, stability, or patient-reported quality of life (ML-QOL) between the groups at 1 year.

Conclusion: With the numbers available in this study, we were unable to demonstrate a difference between early and late knee rehabilitation with regard to knee stiffness, laxity, or patient-reported quality of life outcomes. The results of this small, randomized pilot study suggest a potential role for early rehabilitation after multiligament reconstruction for knee dislocation, which should be further explored in larger multi-institutional studies.

Level of evidence: Level II, therapeutic study.

Purpose: To examine existing literature on objective and patient-reported outcomes and complications after anterior cruciate ligament reconstruction (ACLR) with bone-quadriceps-tendon (B-QT) or soft tissue-quadriceps tendon (S-QT) to further clarify the role of graft type in primary ACLR.

Methods: In accordance with PRISMA guidelines, PubMed, Embase, and Medline were searched in October 2019 for English-language, human studies of all evidence levels on patients undergoing primary ACLR with B-QT or S-QT autograft.

Results: 24 of 1,381 studies satisfied criteria, with 20 using B-QT (1,534 patients, mean age 29.6 years [range 14 to 59], mean follow-up 41.2 months [range 12 to 120]) and 5 using S-QT (181 patients, mean age 32.4 years [range 15 to 58), mean follow-up 25.5 months [range 12 to 46]). International Knee Documentation Committee (IKDC) scores were 67.3 to 89.5 with B-QT and 80.4 to 81.6 with S-QT. Lysholm scores were 85.7 to 97.4 with B-QT and 81.6 to 89.2 with S-QT. More B-QT patients demonstrated rotatory laxity on pivot shift compared with S-QT (0% to 39% versus 0%, respectively). The most common complication was graft rupture, and no differences were observed between graft choices (B-QT 0% to 9% versus S-QT 0% to 3.8%).

Conclusions: The main findings from this review report that more B-QT patients demonstrated postoperative rotatory instability than S-QT patients, and that there are no differences in graft rupture between the 2 graft choices. Although statistical conclusions may not be drawn because of heterogeneity in reporting, it appears that the B-QT group featured much wider major and minor complication profiles.

Level of evidence: IV, systematic review of level I-IV studies.

Keywords: ACL; Allograft; Anterior cruciate ligament; Lateral extra-articular tenodesis; Quadriceps tendon; Revision.

Keywords: ACL reconstruction; Anatomic double-bundle; Anatomic single-bundle; Anterior cruciate ligament; Kinematics; Randomized clinical trial.

Keywords: ACL reconstruction; Graft size measurement; MRI; Preoperative planning; Quadriceps tendon autograft; Ultrasound.

Purpose: To assess the length and thickness of the quadriceps tendon (QT) and anterior cruciate ligament (ACL) to predict the required QT length for individual ACL reconstruction.

Methods: Thirty patients (9 females, 21 males; mean age 24.5 years; mean height 169.3 cm) who underwent ACL reconstruction using the QT with a bone plug autograft were enrolled. The length and thickness of the QT on preoperative magnetic resonance imaging (MRI) were compared with those measured under direct visualization. The ACL length was measured on preoperative MRI and three-dimensional computed tomography after ACL reconstruction. The QT length on MRI was compared with the required graft length, and the factors related to an adequate QT length were assessed.

Results: The mean QT length on MRI was 60.8 ± 1.3 mm and was significantly positively correlated with the QT length under direct visualization (P < 0.01). On MRI, the mean ACL length was 30.8 ± 1.2 mm and the mean QT thickness was 6.3 ± 0.2 mm. Although the mean QT was 0.1 mm longer than the mean required graft length, the QT on MRI was shorter than the required graft length in 37% of patients (11/30). Adequate QT length was related to a QT length of more than 60 mm, but not to age, sex, height, or ACL length.

Conclusion: Although preoperative MRI predicted the required QT length for ACL reconstruction, 37% of patients lacked an adequate QT length, and a QT shorter than 60 mm required the addition of patellar bone.

Level of evidence: III.

Keywords: ACL; Anterior cruciate ligament; Anterior cruciate ligament reconstruction; Complication; Graft; Hamstrings; Infection; Quadriceps; Revision; Septic arthritis; Tendon.

Keywords: ACL; Anterior cruciate ligament; Antibiotic; Complication; Infection; Local; Presoaking; Septic arthritis; Vancomycin.

Keywords: ACL reconstruction; Cosmesis; Regional hypoesthesia; Sensory outcome.

Keywords: ACL reconstruction; Cosmesis; Regional hypoesthesia; Sensory outcome.

Keywords: Anterior cruciate ligament; Infra-patellar branch; Numbness; Saphenous nerve.

Keywords: ACL; Anterior cruciate ligament; Anterior cruciate ligament reconstruction; Complication; Graft; Hamstrings; Infection; Quadriceps; Revision; Septic arthritis; Tendon.

This review is aimed to compare suspensory and aperture quadriceps tendon autograft femoral and tibial fixations in primary anterior cruciate ligament reconstruction (ACL-R), and the clinical outcomes and complication profiles of each fixation method. Greater understanding of the optimal graft fixation technique for quadriceps tendon (QT) autografts may assist surgeons in improving outcomes after ACL-R. PubMed, Embase, and Medline were searched from database inception to September 2017, and again to July 2018, and identified 3,670 articles, 21 studies of which satisfied inclusion/exclusion criteria. Across included studies, 1,155 QT ACL-R patients (mean age, 28.7 years [range, 15-59 years], with mean postoperative follow-up of 36.1 months [range, 3.4-120 months]), were analyzed. Suspensory fixation on both sides demonstrated a higher percentage of patients (81.7%) achieving the highest rating of “A or B” on the International Knee Documentation Committee (IKDC) knee ligament examination form compared with aperture fixation on both sides (67.7%). Moreover, suspensory fixation had a lower side-to-side difference in anterior laxity (1.6 mm) when compared with aperture fixation (2.3 mm). Among studies which reported graft failure, all of which employed aperture fixation, the rate was 3.2%. Across available data, primary ACL-R using QT grafts appears to have successful short-term outcomes with a short-term graft failure rate of 3% independent of fixation method. While there is limited data regarding the comparison of aperture and suspensory soft-tissue quadriceps tendon (SQT) fixation in ACL-R, the findings of this systematic review suggest that suspensory fixation and aperture fixation in both the femoral and tibial tunnels are equally efficacious based on clinical outcome data on IKDC grade and measured laxity. This is a level IV, systematic review study.

Keywords: Anterior cruciate ligament reconstruction; Bone-patellar tendon-bone grafts; Meta-analysis; Quadriceps muscle.

Purpose: The quadriceps tendon (QT) has recently gained interest as an anterior cruciate ligament reconstruction (ACLR) autograft. There is a paucity of data from large cohort studies on failures and revision rates after ACLR using the QT graft. The purpose of the present study is to use the Danish Knee Ligament Reconstruction Registry (DKRR) to compare revision rates, objective knee stability and subjective clinical outcomes in patients who have undergone ACLR with QT, hamstring tendon (HT), and patellar tendon (PT) as a graft for ACLR. It was hypothesized that QT autografts would result in similar objective knee stability and revision rates as HT and PT autografts.

Methods: Data on primary ACLRs in the DKRR from 2005 through 2017 were analyzed. Knee injury and Osteoarthritis Outcome Scores (KOOS), Tegner activity scale scores, sagittal knee laxity, pivot-shift tests at 1-year follow-up and revision rates at 2-year follow-up were compared for the three autograft cohorts.

Results: A total of 531 QT, 14,213 HT and 1835 PT ACLR were registered in the DKLR between 2005 and 2017. QT autograft was associated with statistically significant increased laxity (1.8 mm) compared to HT autograft (1.5 mm) (p < 0.001) and more positive pivot shift. There was a significant higher revision rate for QT (4.7%), compared to PT (1.5%) and HT (2.3%) autografts at 2-year follow-up (p < 0.002).

Conclusion: Quadriceps tendon autografts for ACLR was associated with higher revision rates than HT and PT grafts. QT graft was also associated with small increased objective knee laxity and more positive pivot shift than HT and PT grafts.

Level of evidence: III.

Background: The effects of different autograft types for anterior cruciate ligament reconstruction (ACL-R) on muscle function are sparsely investigated in randomized controlled trials. Our aim was to investigate the effects of quadriceps tendon autograft (QTB) vs. semitendinosus-gracilis autograft (StG) on thigh muscle strength and functional capacity, and a patient-reported outcome 1 year after ACL-R, and to compare the results to healthy controls.

Methods: ACL-R patients (n = 100) and matched controls (CON, n = 50) were recruited, with patients being randomly assigned to QTB (n = 50) or StG (n = 50) ACL-R. One year after ACL-R, bilateral knee extensor (KE) and flexor (KF) muscle strength (isometric, dynamic, explosive, limb symmetry index [LSI], hamstring:quadriceps ratio [HQ ratio]) were assessed by isokinetic dynamometry, along with functional capacity (single leg hop distance [SHD]) and a patient-reported outcome (International Knee Documentation Committee [IKDC] score).

Results: KE muscle strength of the operated leg was lower (9-11%) in QTB vs. StG as was KE LSI, while KF muscle strength was lower (12-17%) in StG vs. QTB as was KF LSI. HQ ratios were lower in StG vs. QTB. Compared with the controls, KE and KF muscle strength were lower in StG (10-22%), while KE muscle strength only was lower in QTB (16-25%). Muscle strength in the StG, QTB, and CON groups was identical in the non-operated leg. While SHD and IKDC did not differ between StG and QTB, SHD in both StG and QTB was lower than CON. The IKDC scores improved significantly 1 year following ACL-R for both graft types.

Conclusion: One year after ACL-R, muscle strength is affected by autograft type, with StG leading to impairments of KE and KF muscle strength, while QTB results in more pronounced impairments of KE only. Functional capacity and patient-reported outcome were unaffected by autograft type, with the former showing impairment compared to healthy controls.

Clinical trials registration number: NCT02173483.

Purpose: Restoration of knee muscle strength is associated with better outcomes following anterior cruciate ligament (ACL) reconstruction, but little is known about the outcome of strength following quadriceps tendon autograft (QT) ACL reconstruction in relation to other graft types. The aim of this review was to evaluate strength outcomes of the knee extensors and knee flexors following QT ACL reconstruction compared to (1) the non-reconstructed contralateral limb and (2) alternative ACL graft types.

Methods: Four electronic databases were searched up until 21st February 2020. Summary meta-analyses were performed comparing knee strength outcomes following QT ACL reconstruction to the contralateral limb by way of limb symmetry index (LSI). Comparative meta-analyses were performed comparing QT ACL reconstruction to alternative ACL grafts for the two most frequently reported strength outcome measures which were peak knee extensor torque LSI, and peak knee flexor torque LSI at the following post-operative periods: 3, 5-8, 9-15, 24, 36-60 months.

Results: In total, 18 studies met the inclusion criteria. Knee strength outcomes of 952 QT ACL reconstructions were included and compared to either the contralateral limb or 1 of 4 alternative ACL graft types; 245 hamstring tendon autograft (HT), 143 patellar tendon autograft (PT), 45 quadriceps tendon allograft, and 21 tibialis anterior allograft. Knee extensor strength LSI following QT ACL reconstruction did not reach 90% even at 24 months post-operatively. Conversely, knee flexor strength LSI following QT ACL reconstruction exceeded 90% at the 9-15 months post-operative period. Knee extensor strength at 5-8 months following QT ACL reconstruction appears similar to PT but weaker than HT ACL reconstruction. In addition, peak knee flexor LSI was significantly greater at 5-8 months in QT ACL reconstruction patients compared to HT patients.

Conclusion: The decision to utilize a QT graft for ACL reconstruction should include consideration of strength outcomes. Knee extensor strength recovery following QT ACL reconstruction appears not to be restored before 24 months.

Level of evidence: Level IV.

Keywords: knee; rehabilitation; therapy.

Keywords: ACL reconstruction; Athletes; Patellar tendon; Press-fit fixation; Quadriceps autograft.

Keywords: ACL reconstruction; Bone–patellar tendon–bone graft; Donor site morbidity; Free quadriceps tendon autograft; Hamstring autograft.

Significant controversy exists regarding the optimal surgical technique for anterior cruciate ligament (ACL) reconstruction in adolescents with 1 to 3 years of skeletal growth remaining. Graft choice and physeal injury remain primary concerns given significantly elevated rates of failure of hamstring autograft reconstructions in this population, as well as risks of leg-length discrepancy and growth axis deviation. Traditional (more vertical) transtibial drilling of the femoral tunnel can reduce risks of physeal injury but has been shown to have less accuracy in restoring the native femoral ACL footprint and associated incomplete knee stabilization. On the other hand, anteromedial and outside-in drilling yields improvements in the tunnel location and biomechanics but at the cost of a more oblique trajectory and greater risk of physeal injury. A hybrid transtibial pin technique using a Pathfinder guide facilitates femoral drilling with the “best of both worlds,” allowing for reproduction of the native ACL footprint and a more physeal-respecting femoral tunnel. When combined with an all-soft tissue quadriceps tendon autograft and suspensory fixation, the hybrid transtibial method yields a reliable, safe, and robust construct with promising results for the young athlete. We describe our preferred graft harvest, tunnel drilling, and fixation techniques to minimize physeal risks and optimize outcomes.

Keywords: ACL reconstruction; Clinical outcomes; Hamstring tendon; Patellar tendon; Quadriceps tendon.

Keywords: ACL; Anterior cruciate ligament; Antibiotics; Arthroscopy; Complication; Failure; Infection; Local; Prevention; Revision; Septic arthritis; Vancomycin.

Keywords: Anterior cruciate ligament injury; Escala Lysholm-Tegner; Hamstring tendon; Isquiotibiales; Lesión de ligamento cruzado anterior; Lysholm score; Quadriceps tendon; Tendón cuádriceps.

Keywords: ACL reconstruction; All inside; Quad tendon.

Keywords: Anterior cruciate ligament; Artificial ligament; Knee function; Knee stability; Tendon allograft; Tendon autograft.

Keywords: Anterior cruciate ligament; Laxity; Patient outcome; Reconstruction.

Keywords: ACL reconstruction; clinical outcomes; hamstring tendon; quadriceps tendon.

Keywords: Anterior cruciate ligament; Hamstring tendon autograft; Proprioception; Quadriceps tendon autograft; Tibialis anterior tendon allograft.

Keywords: Anterior cruciate ligament (ACL); Graft; Quadriceps tendon; Reconstruction.

Keywords: ACL reconstruction; anterior cruciate ligament; pediatrics; quadriceps tendon–patellar autograft.

Keywords: anterior cruciate ligament; bone–patellar tendon–bone; hamstring tendon; quadriceps tendon.

Keywords: all–soft tissue quadriceps tendon autograft; anterior cruciate ligament reconstruction; bone–patellar tendon–bone autograft; quad tendon anterior cruciate ligament.

Keywords: ACL reconstruction; clinical outcomes; hamstring tendon; quadriceps tendon.

Keywords: quadriceps tendon; skeletally immature; transphyseal ACL reconstruction.

Keywords: Anterior cruciate ligament; Laxity; Patient outcome; Reconstruction.

Anterior cruciate ligament (ACL) reconstruction is one of the most common orthopaedic surgeries performed on active people in the world. One of the most important surgical decisions is graft type for use in the reconstruction. Despite extensive research on optimal graft choice for ACL reconstruction, discrepancy exists among practicing surgeons’ graft preference. Recently, the quadriceps tendon has gained popularity for use as a graft source for ACL reconstruction. The all soft tissue quadriceps graft offers many advantages over other autograft choices. Histologically it has 20% more collagen fibrils per cross-sectional area than the patellar tendon (PT). Biomechanically, its ultimate load is 70% > than that of a similar width PT graft, while its modulus is more similar to the native ACL than either the PT or hamstring graft. Anatomically the quadriceps tendon has significantly more volume than the PT. Thus, even after harvest of the quadriceps graft, the remaining quadriceps tendon is still 80% stronger than the intact PT! The length and cross-sectional area of the quadriceps tendon graft can be tailored to the needs of the patient. On any patient over 5 feet tall, a graft length of 7 cm can be obtained. Because the thickness of the tendon is almost twice the thickness of the same patient’s PT, a graft diameter from 7 to 11 mm can easily be achieved. Thus, this graft can be customized for both primary and revision surgeries. Harvest site morbidity is minimal. An incision less than 2 cm in an area with no significant cutaneous nerves without harvest of any patella bone leads to no significant harvest site pain, numbness, or palpable defect. Clinical outcomes using this graft are excellent. Our prospective data on nearly 1,000 grafts, with a mean patient age of 20 years old, show a 4.2% failure rate. Thus, the all soft tissue quadriceps graft will be the surgical choice for ACL reconstruction for future athletes.

Many surgeons use quadriceps tendon (QT) graft for anterior cruciate ligament (ACL) revision surgery; however, despite excellent clinical results, the QT has not achieved universal acceptance for primary ACL reconstruction. One of the reasons for this may be that the QT is technically demanding to harvest and the scar from open harvesting techniques is less cosmetically favorable than that from hamstring tendon techniques. Recent evidence has suggested that broad flat QT grafts may more closely mimic native ACL “ribbon-like” morphology than hamstring tendon grafts. Furthermore, rectangular bone tunnels may more accurately re-create native ACL attachments, allowing grafts to simulate native ACL rotation during knee flexion and potentially improving biomechanics. Rectangular tunnels have further advantages in revision cases, in which-in comparison with round tunnels-they have reduced overlap with pre-existing transtibial tunnels, increasing the chance of bypassing primary tunnels during revision surgery. Finally, instrumentation for minimally invasive QT harvesting has reduced technical difficulty and improved cosmetic results. Hence, technical and cosmetic concerns are no longer barriers to QT use. These anatomic and biomechanical advantages and technical developments make the QT an increasingly attractive option for both primary and revision ACL reconstruction.

Keywords: MPFL; Medial patellofemoral ligament; Patella dislocation; Patella instability; Quadriceps tendon.

Keywords: ACL; arthroscopic surgery; knee injuries; quadriceps.

Keywords: Children and adolescents; Medial patellofemoral ligament; Open growth plate; Patellofemoral instability; Quadriceps tendon graft; Trochlear dysplasia.

Keywords: ACL reconstruction; Anterior cruciate ligament; Anterior knee pain; Hamstring tendon; Patient-reported outcome; Quadriceps tendon.

Keywords: anterior cruciate ligament; quadriceps tendon; sports medicine.

Keywords: Anterior cruciate ligament; Anterior cruciate ligament reconstruction; Biomechanics; Femoral fixation; Hamstring tendon graft; Interference screw; Quadriceps tendon graft.

Keywords: ACL reconstruction; Mechanical properties; Quadriceps tendon; Structural properties; Tendon graft.

Keywords: ACL reconstruction; Free quadriceps tendon; Hamstring tendons; Pain.

Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

© 2016 The Author(s).

Keywords: ACL; Rehabilitation; Risk factor; Sports.

Keywords: Knee; Muscles; Osteoarthritis; Rehabilitation; Resistance training.

The exclusive autograft choice for medial collateral ligament (MCL) reconstruction that has been described until today is the semitendinosus tendon. However, this has some potential disadvantages in a knee with combined MCL-anterior cruciate ligament (ACL) injury, including weakening of the hamstring’s anterior restraining action in an already ACL-injured knee and nonanatomic distal MCL graft insertion when leaving the semitendinosus insertion intact at the pes anserinus during reconstruction. Moreover, because some surgeons prefer to use the hamstring for autologous ACL reconstruction, the contralateral uninjured knee hamstring needs to be harvested as a graft source for the MCL reconstruction if autografts and not allografts are the surgeons’ preference. We describe a technique for performing combined reconstruction of the MCL and ACL using ipsilateral quadriceps tendon-bone and bone-patellar tendon-bone autografts. This technique of MCL reconstruction spares the hamstring tendons and benefits from the advantage provided by bone-to-bone healing on the femur with distal and proximal MCL tibial fixation that closely reproduces the native MCL tibia insertion.

Keywords: Anterior cruciate ligament rehabilitation, Explosive strength, Bone patellar tendon bone autograft, Muscular recovery.

Keywords: Anatomical; Anterior cruciate ligament; Muscle recovery; Quadriceps tendon.

Keywords: ACL reconstruction; Mechanical properties; Quadriceps tendon; Structural properties; Tendon graft.

Purpose: To quantify the structural and material properties of 10-mm central sections of the quadriceps and patellar tendons in the setting of anterior cruciate ligament reconstruction using cadaveric grafts and biomechanical analysis.

Methods: The structural and mechanical properties of 11 bone-patellar tendon-bone (BPTB) and 12 quadriceps tendon-bone (QT) allografts were evaluated. Ten-millimeter-wide tendon grafts from both patellar and quadriceps tendons were harvested and subjected to biomechanical testing using the MTS servohydraulic test machine (MTS Systems, Eden Prairie, MN). The cross-sectional area was also calculated and compared between the BPTB and QT grafts.

Results: The mean cross-sectional area was 91.2 ± 10 mm(2) for the QT compared with 48.4 ± 8 mm(2) for the BPTB (P = .005). The mean ultimate stress was 23.9 ± 7.4 MPa for the QT and 33.4 ± 9.0 MPa for the BPTB (P = .01). Ultimate strain was similar between the 2 tested groups, with a 10.7% change in the QT group and an 11.4% change in the BPTB group (P = .484). The Young modulus of elasticity was 255.3 ± 64.1 MPa for the QT and 337.8. ± 67.7 MPa for the BPTB (P = .006). The mean stiffness was 466.2 ± 133 N/mm for the QT and 278.0 ± 75 N/mm for the BPTB (P = .005). The mean ultimate load to failure was 2,185.9 ± 758.8 N for the QT compared with 1,580.6 ± 479.4 N for the BPTB (P = .045).

Conclusions: The cross-sectional area of the QT was nearly twice that of the BPTB. Ultimate load to failure and stiffness were also significantly higher for the QT graft. The variability in the cross-sectional area was similar in both tendon groups.

Clinical relevance: On the basis of graft predictability and biomechanical properties, our study reaffirms that the QT graft is a biomechanically sound alternative for anterior cruciate ligament reconstruction.

Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Background: Bone tunnel enlargement is a phenomenon present in all anterior cruciate ligament (ACL)- reconstruction techniques. It was hypothesized that press-fit fixation using a free autograft bone plug reduces the overall tunnel size in the tibial tunnel.

Methods: In a prospective cohort study twelve patients who underwent primary ACL reconstruction using an autologous quadriceps tendon graft and adding a free bone block for press-fit fixation (PF) in the tibial tunnel were matched to twelve patients who underwent ACL reconstruction with a hamstring graft and interference screw fixation (IF). The diameters of the bone tunnels were analysed by a multiplanar reconstruction technique (MPR) in a CT scan three months postoperatively. Manual and instrumental laxity (Lachman test, Pivot-shift test, Rolimeter) and functional outcome scores (International Knee Documentation Committee sore, Tegner activity level) were measured after one year follow up.

Results: In the PF group the mean bone tunnel diameter at the level of the joint entrance was not significantly enlarged. One and two centimeter distal to the bone tunnel diameter was reduced by 15% (p = .001). In the IF group the bone tunnel at the level of the joint entrance was enlarged by 14% (p = .001). One and two centimeter distal to the joint line the IF group showed a widening of the bone tunnel by 21% (p < .001) One and two centimeter below the joint line the bone tunnel was smaller in the PF group when compared to the IF group (p < .001). No significant difference for laxity test and functional outcome scores could be shown.

Conclusion: This study demonstrates that press-fit fixation with free autologous bone plugs in the tibial tunnel results in significantly smaller diameter of the tibial tunnel compared to interference screw fixation.

Keywords: Anatomical reconstruction; Anterior cruciate ligament; Knee kinematics; Robotic testing system; Single-bundle.

Keywords: Anatomical reconstruction; Anterior cruciate ligament; Knee kinematics; Robotic testing system; Single-bundle.

Keywords: ACL; ACL reconstruction; dynamic stability; knee; performance.

Purpose: Quadriceps tendon grafts have renewed interest for ACL reconstruction; however, biomechanical studies comparing anatomic single-bundle (SB) and double-bundle (DB) reconstruction techniques are rare. The purpose of this study was to compare the knee biomechanics in four different types of anatomic ACL reconstruction techniques, using the quadriceps tendon in a human cadaver.

Methods: Four different tibial (T) and femoral (F) tunnel configurations, (a) DB-2F-2T, (b) DB-2F-1T, (c) SB-1F-1T and (d) DB-1F-2T, were used for ACL reconstruction using the split quadriceps tendon with patella bone. Ten cadaver knees were subjected to an 89 N anterior tibial load and combined 7 N m valgus and 5 N m internal torques. The anterior tibial translation (ATT) and in situ force were measured using a robotic system for the ACL-intact, ACL-deficient and ACL-reconstructed knees.

Results: DB reconstructions mostly restored ATT to the intact ACL. The in situ forces under the anterior load in the DB reconstructions were similar to the intact ACL, but that of the SB reconstruction was different at 30°, 60° and 90° of flexion (P < 0.05). Under combined torques, the in situ force of the SB graft was less than that of intact ACL at 0°, 15° and 30° of knee flexion (P < 0.05), while that of the ACL DB reconstruction was similar to the intact ACL.

Conclusion: DB ACL reconstruction using quadriceps tendon can restore biomechanics of the knee to that of the intact ACL regardless of whether three or four tunnels are used, but SB reconstruction does not.

Purpose: The purpose of this study was to report the potential differences associated with graft maturity measured on magnetic resonance imaging (MRI) between quadriceps tendon with bone block and hamstring tendon autografts 6 months after ACL reconstruction.

Methods: Twenty-six patients (15 male, 11 female; mean age 29.4 ± 17 years, range 13-46 years) who had undergone anatomic SB ACL reconstruction with either hamstring or quadriceps tendon with bone block autografts and had postoperative MRI 6 months after surgery. In 12 cases, the quadriceps tendon with bone block was used and hamstring in 14 cases. The signal/noise quotient was calculated to compare the difference between quadriceps tendon with bone block and hamstring autografts.

Results: Mean signal/noise quotient is lesser in quadriceps tendon with bone block (1.74 ± 0.39) compared with HS (2.44 ± 0.61) autografts (p = 0.020). For hamstring autograft, the distal region showed a significantly lower mean signal/noise quotient value compared with middle region, and the mean signal/noise quotient value in proximal region was the highest (distal vs middle p < 0.001; middle vs proximal p = 0.007; proximal vs distal p < 0.001). The mean signal/noise quotient of proximal region in quadriceps tendon with bone block autograft was lesser than that in hamstring. The middle region of the quadriceps tendon with bone block graft demonstrated the greatest signal/noise quotient [distal vs middle p = 0.001; middle vs proximal p = 0.027; proximal vs distal (n.s.)].

Conclusion: The maturity of quadriceps tendon with bone block was better in comparison with hamstring 6 months after anatomic SB ACL reconstruction. This study is clinically relevant in that modifying the individual rehabilitation according to the extent of graft maturity may be necessary to optimize patient function and prevent re-injury of the ACL graft.

Keywords: ACL reconstruction; isokinetic test; rehabilitation.

Keywords: Biomechanics; Knee; MPFL; Quadriceps tendon reconstruction; Stiffness.

Keywords: MPFL reconstruction; Minimal invasive MPFL reconstruction; Quadriceps tendon.

Quadriceps tendon with a patellar bone block may be a viable alternative to Achilles tendon for anterior cruciate ligament reconstruction (ACL-R) if it is, at a minimum, a biomechanically equivalent graft. The objective of this study was to directly compare the biomechanical properties of quadriceps tendon and Achilles tendon allografts. Quadriceps and Achilles tendon pairs from nine research-consented donors were tested. All specimens were processed to reduce bioburden and terminally sterilized by gamma irradiation. Specimens were subjected to a three phase uniaxial tension test performed in a custom environmental chamber to maintain the specimens at a physiologic temperature (37 ± 2 °C) and misted with a 0.9 % NaCl solution. There were no statistical differences in seven of eight structural and mechanical between the two tendon types. Quadriceps tendons exhibited a significantly higher displacement at maximum load and significantly lower stiffness than Achilles tendons. The results of this study indicated a biomechanical equivalence of aseptically processed, terminally sterilized quadriceps tendon grafts with bone block to Achilles tendon grafts with bone block. The significantly higher displacement at maximum load, and lower stiffness observed for quadriceps tendons may be related to the failure mode. Achilles tendons had a higher bone avulsion rate than quadriceps tendons (86 % compared to 12 %, respectively). This was likely due to observed differences in bone block density between the two tendon types. This research supports the use of quadriceps tendon allografts in lieu of Achilles tendon allografts for ACL-R.

Purpose: Quadriceps tendon grafts have renewed interest for ACL reconstruction; however, biomechanical studies comparing anatomic single-bundle (SB) and double-bundle (DB) reconstruction techniques are rare. The purpose of this study was to compare the knee biomechanics in four different types of anatomic ACL reconstruction techniques, using the quadriceps tendon in a human cadaver.

Methods: Four different tibial (T) and femoral (F) tunnel configurations, (a) DB-2F-2T, (b) DB-2F-1T, (c) SB-1F-1T and (d) DB-1F-2T, were used for ACL reconstruction using the split quadriceps tendon with patella bone. Ten cadaver knees were subjected to an 89 N anterior tibial load and combined 7 N m valgus and 5 N m internal torques. The anterior tibial translation (ATT) and in situ force were measured using a robotic system for the ACL-intact, ACL-deficient and ACL-reconstructed knees.

Results: DB reconstructions mostly restored ATT to the intact ACL. The in situ forces under the anterior load in the DB reconstructions were similar to the intact ACL, but that of the SB reconstruction was different at 30°, 60° and 90° of flexion (P < 0.05). Under combined torques, the in situ force of the SB graft was less than that of intact ACL at 0°, 15° and 30° of knee flexion (P < 0.05), while that of the ACL DB reconstruction was similar to the intact ACL.

Conclusion: DB ACL reconstruction using quadriceps tendon can restore biomechanics of the knee to that of the intact ACL regardless of whether three or four tunnels are used, but SB reconstruction does not.

Purpose: In August 2011, orthopaedic surgeons from more than 20 countries attended a summit on anatomic anterior cruciate ligament (ACL) reconstruction. The summit offered a unique opportunity to discuss current concepts, approaches, and techniques in the field of ACL reconstruction among leading surgeons in the field.

Methods: Five panels (with 36 panellists) were conducted on key issues in ACL surgery: anatomic ACL reconstruction, rehabilitation and return to activity following anatomic ACL reconstruction, failure after ACL reconstruction, revision anatomic ACL reconstruction, and partial ACL injuries and ACL augmentation. Panellists’ responses were secondarily collected using an online survey.

Results: Thirty-six panellists (35 surgeons and 1 physical therapist) sat on at least one panel. Of the 35 surgeons surveyed, 22 reported performing “anatomic” ACL reconstructions. The preferred graft choice was hamstring tendon autograft (53.1 %) followed by bone-patellar tendon-bone autograft (22.8 %), allograft (13.5 %), and quadriceps tendon autograft (10.6 %). Patients generally returned to play after an average of 6 months, with return to full competition after an average of 8 months. ACL reconstruction “failure” was defined by 12 surgeons as instability and pathological laxity on examination, a need for revision, and/or evidence of tear on magnetic resonance imaging. The average percentage of patients meeting the criteria for “failure” was 8.2 %.

Conclusions: These data summarize the results of five panels on anatomic ACL reconstruction. The most popular graft choice among surgeons for primary ACL reconstructions is hamstring tendon autograft, with allograft being used most frequently employed in revision cases. Nearly half of the surgeons surveyed performed both single- and double-bundle ACL reconstructions depending on certain criteria. Regardless of the technique regularly employed, there was unanimous support among surgeons for the use of “anatomic” reconstructions using bony and soft tissue remnant landmarks.

Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Reconstruction of the medial patellofemoral ligament (MPFL) has recently become a popular procedure for children and adolescents with patellofemoral instability. Nevertheless, high complication rates of up to 26% have been reported. The traditionally used technique requires patellar bone tunnels that may place the proportionately smaller patella at higher risk of fracture. Because of the adjacent physis of the femoral insertion, anatomic reconstruction of the MPFL has the risk of injury to the growth plate. This technical report therefore presents a technique for anatomic reconstruction of the MPFL in a skeletally immature population using a pedicled superficial quadriceps tendon graft, hardware-free patellar graft attachment, and anatomic femoral fixation distal to the femoral physis. The advantages of this technique include avoidance of bony patellar complications, an anatomically truer reconstruction, a single incision, and sparing of the hamstring tendons for reconstruction of any future ligamentous injuries.

Keywords: ACL reconstruction; quadriceps tendon autograft; robotic/UFS testing system.

Implant-free anterior cruciate ligament (ACL) reconstruction is the fixation of ACL grafts without the need for artificial implants. Our aim was to study the evolution of this technique, review the biomechanical evidence and summarise the results. Implant-free graft fixation for bone patella tendon ACL reconstruction was first described in 1987. This concept of implant-free graft fixation was adapted for hamstring and quadriceps tendons as alternative graft sources. Various biomechanical studies have reported that by adhering to certain technical details, this technique provides comparable fixation strength as conventional ACL fixation. The outcome studies of implant-free ACL reconstruction also report clinical results similar to ACL reconstruction with conventional implants.

Keywords: ACL reconstruction; quadriceps tendon autograft; robotic/UFS testing system.

Objective: Restore function of the anterior cruciate ligament (ACL).

Indications: Chronic functional instability with rupture of the ACL, giving way phenomena, acute rupture of the ACL with concomitant meniscus repair, rerupture of ACL graft with anatomical tunnels.

Contraindications: Local infection of the skin at the knee joint, local soft tissue damage, after rupture of the quadriceps tendon, enthesopathia of the quadriceps tendon, lack of patient compliance.

Surgical technique: Harvest quadriceps tendon graft with a bone block via a 4-5 cm long incision, starting from the middle third of the proximal patella pole without damaging the tendon fibers. Drill the femoral tunnel via a deep anteromedial portal with the knee flexed of more than 110° (tunnel diameter 0.5-1 mm smaller in diameter than bone block). Gentle tunnel preparation using dilators. In absence of an ACL stump the lateral meniscus anterior horn serves as tibial landmark. In case of revision surgery, remove graft material and implants from the tunnel. Graft fixation using press fit method in the femoral tunnel. Tibial graft fixation archieved with a resorbable interference screw and a button.

Postoperative management: Goal of the inflammatory phase (weeks 1-2) is pain and inflammation control (20 kg partial weight bearing). During the proliferative phase (weeks 2-6), load and mobility slowly increased (closed-chain exercises). During the remodeling phase (> 6 weeks), strength and coordination exercises are performed. In revision cases and in case of concomitant injuries, longer partial weight-bearing period might be necessary. Athletes should not return to competitive sports before 6-8 months.

Results: In a prospective study, 33 patients (age 16-48 years) were examined after replacement of the ACL with a quadriceps tendon graft after a minimum follow-up (FU) of 2 years (12 revision; 21 primary surgery). No post- or perioperative complications. Postoperative radiographs showed an anatomical tunnel location and no dislocation of the bone block. After 2 years the difference of a-p translation compared to the other leg was assessed by the use of KT 1000. The revision group improved from an average of 7.2 mm (pre-op) to 2.2 mm (FU). The group with primary surgery improved from 6.4 mm (pre-op) to 1.7 mm (FU). A sliding pivot shift phenomenon was detected in 2 patients in the revision group and 1 patient in the primary surgery group.

Keywords: anterior cruciate ligament; arthroscopic surgery; graft; reconstruction; risk factor; smoking.

Purpose: The purposes of this study were to investigate anterior tibial translation under loading conditions after single-bundle (SB) anterior cruciate ligament (ACL) reconstruction using a rectangular tunnel placement strategy with quadriceps and bone–patellar tendon–bone (BPTB) graft and to compare these data with a SB hamstring reconstruction with a round tunnel design.

Methods: In 9 human cadaveric knees, the knee kinematics were examined with robotic/universal force-moment sensor testing. Within the same specimen, the knee kinematics under simulated pivot-shift and KT-1000 arthrometer (MEDmetric, San Diego, CA) testing were determined at 0°, 15°, 30°, 60°, and 90° of flexion under different conditions: intact knee, ACL-deficient knee, and SB ACL-reconstructed knee. For the SB ACL-reconstructed knee, 3 different SB reconstruction techniques were used: a rectangular tunnel strategy (9 × 5 mm) with quadriceps graft, a rectangular tunnel strategy with BPTB graft, and a round tunnel strategy (7 mm) with hamstring graft.

Results: In a simulated Lachman test, a statistically significant difference was found at 0° and 15° of knee flexion between the rectangular reconstruction with quadriceps graft (5.1 ± 1.2 mm and 8.3 ± 2 mm, respectively) or BPTB graft (5.3 ± 1.5 mm and 8 ± 1.9 mm, respectively) and the reconstruction using hamstring graft (7.2 ± 1.4 mm and 12 ± 1.8 mm, respectively) (P = .032 and P = .033, respectively, at 0°; P = .023 and P = .02, respectively, at 15°). On the simulated pivot-shift test at 0° and 15°, rectangular ACL reconstruction with quadriceps graft (3.9 ± 2.1 mm and 6.5 ± 1.7 mm, respectively) or BPTB graft (4.2 ± 1.8 mm and 6.7 ± 1.7 mm, respectively) showed a significantly lower anterior tibial translation when compared with round tunnel reconstruction (5.5 ± 2.1 mm and 7.9 ± 1.9 mm, respectively) (P = .03 and P = .041, respectively, at 0°; P = .042 and P = .046, respectively, at 15°).

Conclusions: Under simulated Lachman testing and pivot-shift testing, a reconstruction technique using a rectangular tunnel results in significantly lower anterior tibial translation at 0° and 15° of flexion in comparison to knees reconstructed with a hamstring SB graft using a round tunnel strategy.

Clinical relevance: ACL reconstruction with a rectangular tunnel and BPTB and quadriceps tendon might result in better anterior knee stability at low flexion angles than ACL reconstruction with hamstring SB graft and a round tunnel in the clinical setting.

Keywords: ACL reconstruction; arthroscopic treatment; clinical case series; quadriceps tendon.

Purpose: To determine the suitability of the quadriceps autograft in primary anterior cruciate ligament (ACL) reconstruction.

Methods: A systematic review was undertaken to identify all clinical studies reporting on the use of the quadriceps tendon autograft in ACL reconstructions. Studies that reported on clinical and functional outcomes, morbidity and complications were selected.

Results: Seventeen articles met our inclusion criteria with a total of 1,580 reconstructions studied. This included four comparative studies which compared the quadriceps tendon to either hamstring or patella tendon autografts. The quadriceps tendon autograft had clinical (Lachman, Pivot-shift testing) and functional outcomes (Lysholm and IKDC scores) similar to those reported for the patella tendon and hamstring grafts in the literature. Comparative studies also reported no significant difference between the grafts for any outcome measure.

Conclusions: The quadriceps tendon autograft is a promising alternative for primary ACL reconstructions with good outcomes and minimal donor site morbidity. Further studies are required, however, to determine whether the quadriceps graft is as good as or better than other autografts.

Level of evidence: IV.

Background: It is commonly believed in medicine that using heat will increase the distensability and flexibility of soft tissue. If true, increased flexibility would be a positive factor to reduce injuries in sports. However, cold should have the opposite effect and is often used to treat sports injuries. This study was accomplished to quantify the effect of heat and cold on the force needed to flex the knee and laxness of the anterior and posterior cruciate ligaments.

Material and methods: The present study examined 20 male and female subjects to determine if heat would increase extensibility of the anterior and posterior cruciate ligaments of the knee and reduce the force needed to flex the knee. Cold exposure was examined to see if it would have the opposite effect. There were 4 experiments in the series: The first was a room temperature series; the second was a series where cold was applied with an ice pack for 20 minutes; in the third, hydrocollator heat packs were applied for 20 minutes; and in the fourth, ThermaCare heat wraps were applied for 4 hours on the quadriceps and knee. Tendon extensibility was measured with a KT2000. The force for flexing the knee was measured by passive movement being applied (CPM) to the knee through 30° and the force required to move the leg was measured.

Results: The results show that the anterior and posterior cruciate ligament flexibility increased and the force needed to move the knee decreased with heat by about 25% compared to cold application.

Conclusions: Heat is beneficial in increasing muscle and ligament flexibility and may help reduce athletic injuries, but cold treatment may have the opposite effect.

Purpose: There is a lack of consensus regarding appropriate criteria attesting patient’s unrestricted sports activities after ACL reconstruction. The purpose of this study was to perform a survey among experienced arthroscopic surgeons regarding their return to play guidelines in these patients.

Methods: A six-item questionnaire was distributed among experienced arthroscopic surgeons (instructors of the German speaking society of arthroscopy, AGA). Study participants were asked to choose from multiple choice answers and had the possibility answering in an open discussion field.

Results: The response rate of the survey was 85.7 %. A total of 83.5 % used autologous hamstring grafts for ACL reconstruction in athletes followed by BPTB (37.2 %) and quadriceps tendon graft (12 %). Approximately 63.5 % recommended a time point later than 6 months allowing return to play after ACL reconstruction in the athlete (after 4 and 6 months 2.3 and 35.3 %, respectively). 76.6 % recommended starting with sports specific rehabilitation after 4 months (21.6 % after 6 months). The most frequent criterion (multiple answers) to allow return to play was negative Lachman test (81.7 % positive answers) followed by free range of motion (78.4 %), negative pivot shift (60.1 %), anterior drawer (45.4 %), proprioception test (43.1 %), muscular strength analysis (40.8 %), single-leg hop jump test (39.0 %), KT 1000 measurement (16.1 %), and MRI (4.1 %). Of the surgeons 85.8 % did not use any of the given scores as criterion to allow return to competitive sports (subjective IKDC score 10.6 %, Lysholm score 8.3 %, objective IKDC score 7.4 %, Tegner activity scale 3.7 %).

Conclusion: In conclusion, the majority of surgeons do not consider muscle function, jump tests, alignment tests, and proprioception as relevant return to sports criterion. However, these are two crucial parameters for return to sports.

Background: Recent studies have shown that an early start of open kinetic chain (OKC) exercises for quadriceps strengthening in a full range of motion (ROM) could increase anterior knee laxity after anterior cruciate ligament (ACL) reconstruction with flexor tendons. However, there are no clinical trials that evaluated outcomes of OKC exercises in a restricted ROM for pain, function, muscle strength, and anterior knee laxity at 1 year after surgery.

Purpose: To determine if an early start of OKC exercises for quadriceps strength in a restricted ROM would promote a clinical improvement without causing increased anterior knee laxity in patients after ACL reconstruction.

Study design: Randomized controlled clinical trial; Level of evidence, 1.

Methods: A total of 49 patients between 16 and 50 years of age who underwent ACL reconstruction with semitendinosus and gracilis autografts were randomly assigned to an early start OKC (EOKC) exercise group or a late start OKC (LOKC) exercise group. The EOKC group (n = 25; mean age, 26 years) received a rehabilitation protocol with an early start of OKC (fourth week postoperatively) within a restricted ROM between 45° and 90°. The LOKC group (n = 24; mean age, 24 years) performed the same protocol with a late start of OKC exercises between 0° and 90° (12th week postoperatively). Quadriceps and hamstring muscle strength, 11-point numerical pain rating scale (NPRS), Lysholm knee scoring scale, single-legged and crossover hop tests, and anterior knee laxity were measured to assess outcomes at the 12-week, 19-week, 25-week, and 17-month postoperative follow-up (range, 13-24 months).

Results: No difference (P < .05) was noted between groups with respect to demographic data. Both groups (EOKC and LOKC) had a higher level of function and less pain at the 19-week, 25-week, and 17-month assessments when compared with 12 weeks postoperatively (P < .05). The EOKC group had improved quadriceps muscle strength at the 19-week, 25-week, and 17-month follow-up when compared with 12 weeks postoperatively (P < .05); the LOKC group showed improvement only at the 17-month postoperative assessment. However, the analysis between groups showed no difference for all pain and functional assessments, including anterior knee laxity (P > .05).

Conclusion: An early start of OKC exercises for quadriceps strengthening in a restricted ROM did not differ from a late start in terms of anterior knee laxity. The EOKC group reached the same findings in relation to pain decrease and functional improvement when compared with the LOKC group but showed a faster recovery in quadriceps strength. The nonweightbearing exercises seem appropriate for patients who have undergone ACL reconstruction, when utilized in a specific ROM. The magnitude of difference in quadriceps strength between the 2 rehabilitation protocols was around 5%; however, this difference was not clinically significant, especially because both groups had equal function on the hop tests.

Objectives: This study aims to evaluate midterm clinical results of the use of two autogenous graft types.

Patients and methods: Between June 2005 and November 2010, clinical data of 44 patients who were operated were retrospectively analyzed. Quadriceps tendon-patellar bone autograft was used for reconstruction surgery in 23 patients (QT-PB group), while quadrupled hamstring tendon autograft was used in 21 patients (HT group). The Tegner’s activity scale, Lysholm scoring system, single-leg-hop test and KT-2000 arthrometric measurements were used for data collection.

Results: The mean length of follow-up was 37.6 months. Although the mean Lysholm score increased in both groups, excellent results in HT group were two-fold higher compared to QT-PB group. The mean laxity for the operated knee joint was 5.65 mm (3.5 to 8.0 mm) in QT-PB group and 3.67 mm (3.0 to 5.5 mm) in HT group. Head-to-head analysis using KT-2000 arthrometer demonstrated that 12 patients (52.1%) in QT-PB group and two patients (9.6%) in HT group had more than 3 mm of anterior laxity difference.

Conclusion: Quadrupled hamstring tendon autograft is superior to central quadriceps tendon-patellar bone in arthroscopic anterior cruciate ligament reconstruction surgery.

Copyright © 2013 Elsevier Inc. All rights reserved.

Background: Loss of knee extension and a deficit in quadriceps strength are frequently found following anterior cruciate ligament (ACL) reconstruction. The aim of this study was to investigate whether the addition of Eletromyographic Biofeedback (EMG BFB) therapy for the vastus medialis muscle to the in the early phase of the standard rehabilitation programme could improve the range of knee extension and strength after ACL reconstruction more than a standard rehabilitation programme. The correlation between EMG measurement and passive knee extension was also investigated.

Method: Sixteen patients, all of whom underwent endoscopic ACL reconstruction using patellar tendon autograft, were randomly assigned to two groups:• Control group (8 patients): standard rehabilitation protocol; with full weight-bearing postoperative, knee brace (0° extension, 90° flexion), electrical stimulation, aquatics and proprioceptive training.• The EMG BFB group (8 patients): EMG BFB was added to the standard rehabilitation protocol within the first postoperative week and during each session for the next 6 weeks.Each patent attended a total of 16 outpatient physiotherapy sessions following surgery. High-Heel-Distance (HHD) Test, range of motion (ROM) and integrated EMG (iEMG) for vastus medialis were measured preoperatively, and at the 1, 2, 4 and 6-week follow ups. Additionally, knee function, swelling and pain were evaluated using standardized scoring scales.

Results: At 6 weeks, passive knee extension (p < 0.002) and the HHD Test were significantly (p < 0.01) better in the EMG BFB group compared to controls. Integrated EMG (vastus medialis) of the EMG BFB group also showed a significant increase after 2 (p < 0.01) and 6 (p < 0.01) weeks. At the 6-week follow up, no significant (p > 0.01) differences were found between the two groups for the assessment of knee function, swelling and pain.

Conclusion: The results indicate that EMG BFB therapy, in the early phase of rehabilitation after ACL reconstruction, is useful in enhancing knee extension. Improved innervation of the vastus medialis can play a key role in the development of postoperative knee extension. EMG BFB therapy is a simple, inexpensive and valuable adjunct to conventional therapeutic modalities.

Background: This article describes an arthroscopic anterior cruciate ligament (ACL) reconstruction technique with a quadriceps tendon autograft using an anteromedial portal technique.

Methods: A 5 cm quadriceps tendon graft is harvested with an adjacent 2 cm bone block. The femoral tunnel is created through a low anteromedial portal in its anatomical position. The tibial tunnel is created with a hollow burr, thus acquiring a free cylindrical bone block. The graft is then passed through the tibial tunnel and the bone block, customized at its tip, is tapped into the femoral tunnel through the anteromedial portal to provide press-fit fixation. The graft is tensioned distally and sutures are tied over a bone bridge at the distal end of the tibial tunnel. From the cylindrical bone block harvested from the tibia the proximal end is customized and gently tapped next to the graft tissue into the tibial tunnel to assure press fitting of the graft in the tibial tunnel. The distal part of the tibial tunnel is filled up with the remaining bone.All patients were observed in a prospective fashion with subjective and objective evaluation after 6 weeks, 6 and 12 months.

Results: Thirty patients have been evaluated at a 12 months follow-up. The technique achieved in 96.7% normal or nearly normal results for the objective IKDC. The mean subjective IKDC score was 86.1 ± 15.8. In 96.7% the Tegner score was the same as before injury or decreased one category. A negative or 1+ Lachman test was achieved in all cases. Pivot-shift test was negative or (+) glide in 86.7%. The mean side-to-side difference elevated by instrumental laxity measurement was 1.6 ± 1.1 mm. Full ROM has been achieved in 92.3%. The mean single one-leg-hop index was 91.9 ± 8.0 at the follow-up.

Conclusions: Potential advantages include minimum bone loss specifically on the femoral side and graft fixation without implants.

Introduction: Coactivation of the hamstring muscles during dynamic knee extension may compensate for increased knee joint laxity in anterior cruciate ligament (ACL) deficient subjects. This study examined if antagonist muscle coactivation during maximal dynamic knee extension was elevated in subjects with anterior cruciate ligament (ACL) deficiency compared to age-matched healthy controls.

Methods: Electromyography (EMG) and net knee joint moments were recorded during maximal concentric quadriceps and eccentric hamstring contractions, performed in an isokinetic dynamometer (ROM: 90-10°, angular speed: 30°/s). Hamstring antagonist EMG recorded during concentric quadriceps contraction was converted into antagonist moment based on the EMG-moment relationship observed during eccentric agonist contractions.

Results: The magnitude of antagonist hamstring EMG was 65.5% higher in ACL deficient subjects compared to healthy controls (p<0.05). Likewise, antagonist hamstring moment expressed in percentage of the measured net extension moment was elevated in ACL deficient subjects (56 ± 8 to 30 ± 6%) compared to controls (36 ± 5 to 19 ± 2%) at 20-50° of knee flexion (0°=full extension) (p<0.05).

Discussion: The results showed a marked increase in hamstring coactivation towards more extended joint positions. Notably, this progressive rise in coactivation was greater in ACL deficient subjects, which may reflect a compensatory strategy to provide stability to the knee joint in the anterior-posterior plane during isolated knee extension. The present study encourages further investigations of hamstring coactivation in ACL deficient subjects.

Keywords: allograft; anterior cruciate ligament; autograft; reconstruction.

The anterior cruciate ligament reconstruction is a common procedure that improves stability and function of the knee. The surgical technique continues to evolve and many issues are still under debate. These mainly include: (1) graft selection (patellar tendon, hamstring, quadriceps tendon, or allografts), (2) surgical technique (double versus single bundle), and (3) femoral tunnel drilling. Currently, the most controversial one is the femoral tunnel drilling (transtibial vs. anteromedial portal drilling). Common opinion is that drilling the femoral tunnel through the anteromedial (AM) allows a more anatomic placement of the graft and a better rotational stability; therefore, this technique is gaining in popularity compared with the transtibial drilling despite a greater difficulty and the risk of medial condyle damage, tunnel back wall blowout, and inadequate socket length. The aim of this article is to describe the surgical technique of the anterior cruciate ligament reconstruction (single and double bundle), drilling the femoral tunnel through the AM portal.

Anterior cruciate ligament reconstruction is among the most common orthopaedic procedures in the United States, with >200,000 performed annually. Much has been published regarding the use of autograft versus allograft. Bone-patellar tendon-bone is the most frequently used autograft, but hamstring and quadriceps tendon grafts are common alternatives. Each graft has distinct advantages and disadvantages, and selection is individualized. Fixation methods vary by graft type. Fixation resulting in a construct that is too rigid may restrict knee range of motion. Donor site morbidity must be considered, as well. Autograft harvest may result in anterior knee pain, kneeling pain, anterior knee numbness, muscle weakness, and patellar fracture. Appropriate graft selection is essential to optimize outcomes.

Background: One major concern in the treatment of ACL lesions in children and adolescents with open physes is the risk of iatrogenic damage to the physes and a possibly resulting growth disturbance.

Purpose: The primary purpose of this article is to describe our technique of a transphyseal ACL reconstruction using quadriceps tendon-bone autograft in children and adolescents with open growth plates. The secondary aim is to report our early results in terms of postoperative growth disturbances which are considered to be a major concern in this challenging group of patients. It was our hypothesis that with our proposed technique no significant growth disturbances would occur.

Methods: From January 1997 to December 2007 49 consecutive children and adolescents with open growth plates were treated for a torn ACL using the aforementioned surgical technique. The patients (28 males and 21 females) with a median age at surgery of 13 (range 8-15) years were retrospectively evaluated. Outcome measures were follow-up radiographs (weight-bearing long leg radiographs of the injured and uninjured knee, anteroposterior and lateral views, a tangential view of the patella and a tunnel view of the injured knee) and follow-up notes (6 weeks, 3, 6, 12 months and until closing of physes) for occurrence of any tibial and/or femoral growth changes.

Results: All of the 49 patients had a sufficient clinical and radiological follow-up (minimum 5 years, rate 100%). 48 cases did not show any clinical and radiological growth disturbance. One case of growth disturbance in a 10.5 years old girl was observed. She developed a progressive valgus-flexion deformity which was attributed to a malplacement of the autograft bone block within the femoral posterolateral epiphyseal plate leading to an early localized growth stop. None of the patients were reoperated due to ACL graft failure. Five of the patients underwent revision ACL surgery due to another adequate sports trauma after the growth-stop. The tibial fixation screw had to be removed under local anaesthesia in 10 patients.

Conclusions: The described ACL reconstruction technique represents a promising alternative to previously described procedures in the treatment of children and adolescents with open growth plates. Using quadriceps tendon future graft availability is not compromised, as the most frequently used autograft-source, ipsilateral hamstring tendons, remains untouched.

Purpose: Press-fit fixation of patellar tendon bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary. To date, no biomechanical data exist describing an implant-free double-bundle press-fit procedure. The purpose of this study was to characterize the biomechanical properties of three double-bundle press-fit fixations.

Methods: In a controlled laboratory study, the patellar-, quadriceps- and hamstring tendons of 10 human cadavers (age: 49.2 ± 18.5 years) were used. An inside out press-fit fixation with a knot in the semitendinosus and gracilis tendons (SG) combined with an additional bone block, with two quadriceps tendon bone block grafts (QU) was compared with press-fit fixation of two bone patellar tendon bone block (PT) grafts in 30 porcine femora. Constructs were cyclically stretched and then loaded until failure. Maximum load to failure, stiffness and elongation during failure testing and cyclical loading were investigated.

Results: The maximum load to failure was 703 ± 136 N for SG fixation, 632 ± 130 N for QU and 656 ± 127 N for PT fixation. Stiffness of the constructs averaged 138 ± 26 N/mm for SG, 159 ± 74 N/mm for QU, and 154 ± 50 N/mm for PT fixation. Elongation during initial cyclical loading was 1.2 ± 1.4 mm for SG, 2.0 ± 1.4 mm for QU, and 1.0 ± 0.6 mm for PT (significantly larger for PT and QU between the first 5 cycles compared with cycles 15-20th, P < 0.01).

Conclusion: All investigated double-bundle fixation techniques were equal in terms of maximum load to failure, stiffness, and elongation. Unlike with single-bundle press-fit fixation techniques that have been published, no difference was observed between pure tendon combined with an additional bone block and tendon bone grafts. All techniques exhibited larger elongation during initial cyclical loading. All three press-fit fixation techniques that were investigated exhibit comparable biomechanical properties. Preconditioning of the constructs is critical.

Copyright © 2010 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

2010 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Background: There have been no long-term follow-up studies comparing a predominantly home-based rehabilitation program with a standard physical therapy program after anterior cruciate ligament (ACL) reconstruction. Demonstrating the long-term success of such a cost-effective program would be beneficial to guide future rehabilitation practice.

Purpose: To determine whether there were any differences in long-term outcome between recreational athletes who performed a physical therapy-supervised rehabilitation program and those who performed a primarily home-based rehabilitation program in the first 3 months after ACL reconstruction.

Study design: Randomized clinical trial; Level of evidence, 1.

Methods: Patients were randomized before ACL reconstruction surgery to either the physical therapy-supervised (17 physical therapy sessions) or home-based (4 physical therapy sessions) program. Eighty-eight of the original 129 patients returned 2 to 4 years after surgery to assess their long-term clinical outcomes. Primary outcome was the ACL quality of life questionnaire (ACL QOL). Secondary outcomes were bilateral difference in knee extension and flexion range of motion, sagittal plane knee laxity, relative quadriceps and hamstring strength, and objective International Knee Documentation Committee score. Unpaired t tests and a chi-square test were used for the comparisons.

Results: The home-based group had a significantly higher mean ACL QOL score (80.0 +/- 16.2) than the physical therapy-supervised group (69.9 +/- 22.0) a mean of 38 months after surgery (P = .02, 95% confidence interval [CI]: 1.7, 18.4). The mean change in ACL QOL score from before surgery to follow-up was not significantly different between the groups (physical therapy = 40.0, home = 45.8, P = .26, 95% CI: -15.8, 4.4). There were no significant differences in the secondary outcome measures.

Conclusion: This long-term study upholds the short-term findings of the original randomized clinical trial by demonstrating that patients who participate in a predominantly home-based rehabilitation program in the first 3 months after ACL reconstruction have similar 2- to 4-year outcomes compared with those patients who participate in a more clinically supervised program.

Sixty-eight patients were clinically evaluated preoperatively, 3, 5, 7, 9 months, 1 and 2 years after ACL reconstruction, 34 with patellar tendon graft, 34 with hamstring graft. Outcome regarding graft choice and anterior knee laxity (P = 0.04) was in favour of patellar tendon graft. Hamstring graft led to a larger laxity, 2.4 mm compared with patellar tendon graft, 1.3 mm at 1 year and 2.5 mm and 1.5 mm, respectively, at 2 years (P = 0.05). There was a significant difference in rotational knee stability in favour of the patellar tendon graft at all test occasions but 9 months. A general effect regarding graft choice and muscle torque was found at 90 degrees/s for quadriceps (P = 0.03) and hamstrings (P < or = 0.0001) and at 230 degrees/s for hamstrings (P < or = 0.0001). No treatment effect regarding graft choice and one-leg hop test, postural sway or knee function was found. No group differences in anterior knee pain were found at any of the test occasions but 2 years in favour of hamstring graft compared to patellar tendon graft (P = 0.04). Patellar tendon graft resulted in higher activity level than hamstring graft at all test occasions but 1 year (P = 0.01). Patellar tendon ACL reconstruction led to more stable knees with less anterior knee laxity and less rotational instability than hamstring ACL reconstruction. Hamstring graft patients had not reached preoperative level in hamstring torque even 2 years after ACL reconstruction. Athletes with patellar tendon graft returned to sports earlier and at a higher level than those with hamstring graft.

Copyright 2010 Elsevier Inc. All rights reserved.

Purpose: The purpose of this study was to compare the intermediate-term outcomes of anterior cruciate ligament (ACL) reconstruction by use of bone-patellar tendon-bone (BPTB), quadriceps tendon with a bone plug (BQT), and quadriceps tendon without a bone plug (QT).

Methods: We evaluated 198 primary ACL reconstructions in 191 patients at a mean of 55.6 months postoperatively. Assessment included side-to-side comparison of range of motion, arthrometer values, presence of effusion, anterior knee pain, and numbness. Comparisons were made between QT and BQT patients and between men and women. The results were compared with data from 30 patients in a previous study who had undergone ACL reconstruction by the same surgeon (W.R.S.) with BPTB.

Results: Range of motion averaged -3.2 degrees +/- 2.2 degrees of extension to 134.3 degrees +/- 10.2 degrees of flexion for the operative extremity compared with -3.6 degrees +/- 2.07 degrees to 134.2 degrees +/- 10.6 degrees for the contralateral extremity at final follow-up. KT-1000 manual maximum measurements (MEDmetric, San Diego, CA) of the operative extremity averaged 0.94 mm more than those of the normal contralateral knee. When compared with BPTB autograft, the quadriceps tendon autograft showed significantly better results, with less anterior knee pain (4.56% v 26.7%), less anterior numbness (1.5% v 53.3%), a higher percentage of arthrometer measurements showing a side-to-side difference of 0 to 3 mm (88% v 68%), and better extension (mean loss, 0.55 degrees v 2.77 degrees ). There was no significant difference between the 2 groups with regard to loss of flexion, Lachman test, pivot-shift test, presence of effusion, or number of failures.

Conclusions: Central quadriceps tendon autograft, QT or BQT, produces equivalent results when compared directly with BPTB autograft in arthroscopically assisted ACL reconstruction. There was no difference in results between men and women with a quadriceps tendon autograft, either with or without the use of a bone plug. ACL reconstruction using quadriceps tendon autograft is an effective surgical option that reduces donor-site morbidity.

Level of evidence: Level IV, therapeutic case series.

Georg Thieme Verlag KG Stuttgart, New York.

Background: Anatomic double-bundle reconstruction has been thought to better simulate the anterior cruciate ligament anatomy. It is, however, a technically challenging procedure, associated with longer operation time and higher cost.

Hypothesis: Double-bundle anterior cruciate ligament reconstruction using a single femoral and tibial tunnel can closely reproduce intact knee kinematics.

Study design: Controlled laboratory study.

Methods: Eight fresh-frozen human cadaveric knee specimens were tested using a robotic testing system to investigate the kinematic response of the knee joint under an anterior tibial load (130 N), simulated quadriceps load (400 N), and combined torques (5 N.m valgus and 5 N.m internal tibial torques) at 0 degrees, 15 degrees, 30 degrees, 60 degrees, and 90 degrees of flexion. Each knee was tested sequentially under 4 conditions: (1) anterior cruciate ligament intact, (2) anterior cruciate ligament deficient, (3) single-bundle anterior cruciate ligament reconstruction using quadrupled hamstring tendon, and (4) single-tunnel-double-bundle anterior cruciate ligament reconstruction using the same tunnels and quadrupled hamstring tendon graft as in the single-bundle anterior cruciate ligament reconstruction.

Results: Single-tunnel-double-bundle anterior cruciate ligament reconstruction more closely restored the intact knee kinematics than single-bundle anterior cruciate ligament reconstruction at low flexion angles (< or =30 degrees ) under the anterior tibial load and simulated muscle load (P < .05). However, single-tunnel-double-bundle anterior cruciate ligament reconstruction overconstrained the knee joint at high flexion angles (> or =60 degrees ) under the anterior tibial load and at 0 degrees and 30 degrees of flexion under combined torques.

Conclusion: This double-bundle anterior cruciate ligament reconstruction using a single tunnel can better restore anterior tibial translations to the intact level compared with single-bundle anterior cruciate ligament reconstruction at low flexion angles, but it overconstrained the knee joint at high flexion angles.

Clinical relevance: This technique could be an alternative for both single-bundle and double-tunnel-double-bundle anterior cruciate ligament reconstructions to reproduce intact knee kinematics and native anterior cruciate ligament anatomy.

Several techniques of anterior cruciate ligament (ACL) double-bundle reconstruction have been introduced to improve the functional outcome and restore normal kinematics of the knee. Meanwhile, a remnant-preserving technique was developed to preserve the proprioception and to enhance the revascularization of the reconstructed ACL. We developed double-bundle ACL reconstruction technique using autogenous quadriceps tendon graft while preserving the remnant. With this technique, two femoral sockets and one tibial tunnel are made. To preserve the remnant of the ACL, the rotational direction of the reamer was set to counterclockwise just before perforation of the tibial tunnel. To pass the graft more easily without disturbance of the remnant, the graft passage was achieved through the tibial tunnel. We suggest that the remnant-preserving technique could be an effective alternative considering its mechanical stability as well as the proprioception and vascularization recovery in arthroscopic double-bundle ACL reconstruction.

Purpose: The purpose of this study was to evaluate and compare postoperative anterior knee pain, knee stability, and functional scores of an autogenous bone-patellar tendon-bone (BPTB) graft and a quadriceps tendon-bone (QTB) graft.

Methods: A total of 48 patients–27 who had anterior cruciate ligament (ACL) reconstruction by use of an autogenous BPTB graft and 21 who had ACL reconstruction by use of a QTB graft–were assessed at a minimum follow-up of 24 months after surgery. An accelerated rehabilitation program was adapted, and the rehabilitation protocol was identical for both groups.

Results: The mean side-to-side difference as measured with a KT-2000 arthrometer (MEDmetric, San Diego, CA) was 2.73 mm (SD, 1.45 mm) in the BPTB group and 2.79 mm (SD, 1.32 mm) in the QTB group (P = .880). Postoperatively, the International Knee Documentation Committee score was grade A or B in 23 patients (85.2%) in the BPTB group and 18 (85.7%) in the QTB group (P = .997). The mean anterior knee pain score was 86.9 in the BPTB group as compared with 90.2 in the QTB group (P = .107). In a kneeling posture, 13 BPTB patients reported discomfort (moderate in 10 and severe in 3) whereas only 4 QTB patients had moderate discomfort (P = .029). No significant differences were found with regard to other activities surveyed.

Conclusions: A QTB graft attached with the EndoPearl device (Linvatec, Largo, FL) appears to be an effective alternative for single-bundle ACL reconstruction. When followed with an accelerated rehabilitation program, reconstruction with a QTB graft provided knee stability comparable to a BPTB graft but with less kneeling pain than a BPTB graft.

Background: In a patient with generalized ligamentous laxity, the risk of instability is greater with a conventionally reconstructed anterior cruciate ligament. The purpose of this study was to compare the clinical outcome of anterior cruciate ligament reconstruction done with a double-bundle technique with use of a quadriceps tendon-bone autograft and that of a single-bundle reconstruction with use of a bone-patellar tendon-bone autograft in patients with generalized ligamentous laxity.

Methods: The records of sixty-one patients who underwent anterior cruciate ligament reconstruction between June 2002 and October 2005 were evaluated. Thirty-two patients underwent a single-bundle reconstruction (group 1), and twenty-nine patients underwent a double-bundle reconstruction (group 2). Clinical outcomes were determined from data obtained before surgery and at the twenty-four-month follow-up visit.

Results: Postoperatively, the mean side-to-side difference (and standard deviation) in anterior tibial translation, measured with use of a KT-2000 arthrometer, was greater for group 1 (3.37 +/- 1.76 mm; range, 1.00 to 8.00 mm) than for group 2 (2.03 +/- 1.11 mm; range, 0.00 to 3.50 mm) (p = 0.02). Three patients in group 1 had a grade-1+ pivot shift, while no patient in group 2 had an abnormal pivot shift. The mean score on the Hospital for Special Surgery knee ligament questionnaire was 90.8 in group 1 and 92.1 in group 2, and the mean Lysholm score was 89.4 in group 1 and 91.1 in group 2.

Conclusions: On the basis of the evaluation of ligamentous laxity measured by the KT-2000 arthrometer, a double-bundle anterior cruciate ligament reconstruction with use of a quadriceps tendon-bone autograft allows less anterior translation than does a single-bundle reconstruction with use of a bone-patellar tendon-bone autograft. However, we could not identify a significant difference in the functional outcome between the two techniques.

Background and purpose: The authors previously reported that focused eccentric resistance training during the first 15 weeks following anterior cruciate ligament reconstruction (ACL-R) induced greater short-term increases in muscle volume, strength, and measures of function relative to standard rehabilitation. The purpose of this study was to evaluate the effects of early progressive eccentric exercise on muscle volume and function at 1 year after ACL-R.

Participants and methods: Forty patients who had undergone an ACL-R were randomly assigned to 1 of 2 groups: a group that received early progressive eccentric exercise (n=20) and a group that received standard rehabilitation (n=20). Seventeen participants in the eccentric exercise group and 15 participants in the standard rehabilitation group completed a 1-year follow-up. Magnetic resonance images of the thighs were acquired 1 year after ACL-R and compared with images acquired 3 weeks after surgery. Likewise, routine knee examinations, self-report assessments, and strength and functional testing were completed 1 year after surgery and compared with previous evaluations. A 2-factor analysis of variance for repeated measures (group x time) was used to analyze the data.

Results: Compared with the standard rehabilitation group, improvements in quadriceps femoris and gluteus maximus muscle volume in the involved lower extremity from 3 weeks to 1 year following ACL-R were significantly greater in the eccentric exercise group. Improvements in quadriceps femoris and gluteus maximus muscle volume were 23.3% (SD=14.1%) and 20.6% (SD=12.9%), respectively, in the eccentric exercise group and 13.4% (SD=10.3%) and 11.6% (SD=10.4%), respectively, in the standard rehabilitation group. Improvements in quadriceps femoris muscle strength and hopping distance also were significantly greater in the eccentric exercise group 1 year postsurgery.

Discussion and conclusion: A 12-week focused eccentric resistance training program, implemented 3 weeks after ACL-R, resulted in greater increases in quadriceps femoris and gluteus maximus muscle volume and function compared with standard rehabilitation at 1 year following ACL-R.

Keywords: Anterior cruciate ligament; Knee; Muscle skeletal; Quadriceps muscle.

Ligaments and tendons are similar in composition but differ in proportion and arrangement. Tendons are being used as grafts for the ACL reconstruction. Their microscopic structure has not been sufficiently studied and compared to the native ACL. A null hypothesis was declared stating that the anterior cruciate ligament should be histological, morphologically and functionally different from the tendon grafts used for ACL reconstruction. We investigated similarities and differences of the structure of ACL and tendons used as a graft tissue for ACL reconstruction. In this study, standardized samples of quadriceps, hamstrings (semitendinosus and gracilis) and patellar tendons, and the ACL were harvested from 26 autopsies (average age 36.4) and were investigated using light and electron microscopy, immunohistochemistry and morphometry. The thickness of the collagen fibrils, collagen organization and diameter, the fibril/interstitium ratio, density of fibroblasts and blood vessels, and distribution of the collagen type I, III and V fibrils were analyzed. The semitendinosus showed the highest density of fibroblasts and blood vessels, while the gracilis the highest fibril/interstitium ratio. No differences regarding the thickness of collagen fibrils and distribution of fibrils were found. The ACL had the highest concentration of type III and V collagen fibrils as well as elastic fibers. The histological and ultrastructural appearance of the ACL differs from those of the tendons used as graft, for ACL reconstruction. Its ultrastructure is varied and complex, with its collagen fibers bundles lying in many directions.

Ligaments and tendons are similar in composition but differ in proportion and arrangement. Tendons are being used as grafts for the ACL reconstruction. Their microscopic structure has not been sufficiently studied and compared to the native ACL. A null hypothesis was declared stating that the anterior cruciate ligament should be histological, morphologically and functionally different from the tendon grafts used for ACL reconstruction. We investigated similarities and differences of the structure of ACL and tendons used as a graft tissue for ACL reconstruction. In this study, standardized samples of quadriceps, hamstrings (semitendinosus and gracilis) and patellar tendons, and the ACL were harvested from 26 autopsies (average age 36.4) and were investigated using light and electron microscopy, immunohistochemistry and morphometry. The thickness of the collagen fibrils, collagen organization and diameter, the fibril/interstitium ratio, density of fibroblasts and blood vessels, and distribution of the collagen type I, III and V fibrils were analyzed. The semitendinosus showed the highest density of fibroblasts and blood vessels, while the gracilis the highest fibril/interstitium ratio. No differences regarding the thickness of collagen fibrils and distribution of fibrils were found. The ACL had the highest concentration of type III and V collagen fibrils as well as elastic fibers. The histological and ultrastructural appearance of the ACL differs from those of the tendons used as graft, for ACL reconstruction. Its ultrastructure is varied and complex, with its collagen fibers bundles lying in many directions.

The quadriceps tendon autograft can be used for primary and revision anterior cruciate ligament (ACL) reconstruction. Despite several successful clinical reports, graft fixation issues remain, and the ideal technique for fixation continues to be controversial. We present a technique of ACL reconstruction with quadriceps tendon autograft (QTA) using a patellar bone block. The tendon end is fixed in the femoral tunnel and the bone plug in the tibial tunnel using reabsorbable interference screws. The advantages of this technique are related to the increase in stiffness of the graft, the achievement of a more anatomic fixation, and a reduction in synovial fluid leakage.

The bone-patellar tendon-bone has been widely used and considered a good graft source. The quadriceps tendon was introduced as a substitute graft source for bone-patellar tendon-bone. We compared the clinical outcomes of anterior cruciate ligament reconstructions using central quadriceps tendon-patellar bone and bone-patellar tendon-bone autografts. We selected 72 patients who underwent unilateral anterior cruciate ligament reconstruction using bone-patellar tendon-bone between 1994 and 2001 and matched for age and gender with 72 patients who underwent anterior cruciate ligament reconstruction using quadriceps tendon-patellar bone. All patients were followed up for more than 2 years. We assessed anterior laxity, knee function using the Lysholm and International Knee Documentation Committee scores, and quadriceps strength, the means of which were similar in the two groups. More patients (28 or 39%) in the bone-patellar tendon-bone group reported anterior knee pain than in the quadriceps tendon-patellar bone group (six patients or 8.3%). Anterior cruciate ligament reconstruction using the central quadriceps tendon-patellar bone graft showed clinical outcomes comparable to those of anterior cruciate ligament reconstruction using the patellar tendon graft, with anterior knee pain being less frequent in the former. Our data suggest the quadriceps tendon can be a good alternative graft choice.

Level of evidence: Level III Therapeutic study.

Background: Recently, the use of the quadriceps tendon transplant with bone block (patellar bone quadriceps tendon autografts) for anterior cruciate ligament reconstruction has increasingly been reported.

Hypothesis: Clinical results after the implantation of a patellar bone quadriceps tendon autograft fixed with cross-pins or screws will show no significant difference between the 2 techniques with regard to stability, function, and subjective satisfaction.

Study design: Cohort study; Level of evidence, 2.

Methods: Between 1998 and 2004, 193 patients with anterior cruciate ligament ruptures were implanted with a patellar bone quadriceps tendon autograft. For 100 of these patients, fixation was carried out using absorbable cross-pins, and for the remaining 93, fixation was carried out using absorbable screws. The results were evaluated by means of International Knee Documentation Committee, Noyes, and Lysholm scores, as well as KT-1000 arthrometer measurement and subjective satisfaction.

Results: The mean follow-up postoperative control period was 29 months. In the International Knee Documentation Committee overall evaluation, the pin group showed a significantly better result (P =.03). The values of the Noyes score produced no significant differences. The mean value of the Lysholm score was 94 points in the screw group and 89 points in the pin group (P <.001). Overall, 90% of the patients subjectively judged their conditions as good or very good.

Conclusion: With both operating processes examined, 80% to 90% of the cases achieved good to very good results. The use of cross-pins can be recommended for fixing patellar bone quadriceps tendon autografts.

The use of the BPTB-autograft is a very common method for ACL reconstruction. Nevertheless, the problem of the typical donor-site-morbidity is unresolved. Recently, a transplant of quadriceps tendon, with an attached bone block (BQT) has been increasingly relied upon. The purpose of this study was to examine the clinical results of a group of patients after arthroscopic ACL reconstruction using either BPTB or quadriceps tendon autograft after a minimum follow-up of 2 years in terms of knee joint stability and function using both subjective and objective criteria. Retrospective study. A total of 260 patients with ACL ruptures were operated between 1995 and 2000; 124 received a BQT-autograft, including 8 revisions; 136 patients received a BPTB-autograft, exclusively primary interventions. The results were evaluated using the IKDC-, Noyes- and Lysholm-Scores. It was possible to re-evaluate 194 patients after a minimum follow-up period of 2 years, 64 of 260 patients (25%) were lost to follow-up. Ninety-seven percent of the operated knee joints in the BPTB-group were judged as normal or almost normal with the IKDC evaluation, as were 83% in the BQT-group (P < or = 0.001). The BQT-group showed a significantly better result in the evaluation of the donor-site-morbidity. We found no significant differences in the functional outcome according to the Lysholm- and Noyes-Score. In comparison to the results after using a BQT-transplant for reconstruction of a ruptured ACL the use of the BPTB-transplant is in favour concerning patient satisfaction and IKDC evaluation. For patients with activities involving kneeling or prolonged flexion of the knee joint BQT-transplants can be a good alternative, however.

Anterior cruciate ligament (ACL) reconstruction surgery with the central third quadriceps tendon can yield a stable, high-functioning knee with little associated morbidity. Both the quadriceps tendon-patellar bone graft and the free tendon graft are reported to produce good to excellent outcomes at more than 2 years of follow-up. The decreased donor-site morbidity and absence of anterior knee pain suggest that the quadriceps free tendon autograft offers a reliable, pain-free, low-morbidity autograft alternative in ACL reconstruction. Recent data suggest that this graft may be the least morbid of the currently used ACL autograft reconstruction alternatives.

Background: The purpose of this study was to evaluate the peak torque of the knee flexors (H) and the quadriceps muscle (Q) at 12 and 24 weeks after isolated anterior cruciate ligament reconstruction with semitendinosus and gracilis autografts.

Materials and methods: There were 20 patients (8 females, 12 males), with the mean age of 31.5 years. An isokinetic examination of the muscles was performed with a Biodex System 3 isokinetic dynamometer at a speed of 180 degrees/sec. All patients underwent 12 weeks of isokinetic training for 20 minutes 5 times a week (240 degrees/sec for 6 weeks and 180 degrees/sec for 6 weeks) beginning 12 weeks after surgery.

Results: The average peak torque difference between the healthy and operated limb at 12 and 24 weeks postoperatively was 38% and 14% for Q and 25% and 4.3% for H respectively. The decrease in peak torque differences was statistically significant for both H and Q (p=0.05). The decrease in Q peak torque was significantly higher than that of H peak torque 12 and 24 weeks after surgery.

Conclusions: These results indicate that 12-week isokinetic training can increase the peak torque of H and Q by 20% and 24% respectively. An isokinetic examination of Q and H peak torques should become a standard procedure for evidence-based monitoring of the rehabilitation process after anterior cruciate ligament reconstruction.

Purpose: This retrospective study was performed to relate tunnel position as measured by plain radiographs and magnetic resonance imaging (MRI) to residual pivot shift and to determine its clinical relevance after anterior cruciate ligament reconstruction via central quadriceps tendon autograft.

Methods: We reviewed 137 arthroscopic anterior cruciate ligament reconstructions via quadriceps tendon autograft with a minimum of 2 years’ follow-up. Clinical results were evaluated by use of the Lachman test, pivot-shift test, Lysholm score, and Cybex dynamometer (Lumex, Ronkonkoma, NY). Anterior tibial translation was measured with the KT-1000 arthrometer (MEDmetric, San Diego, CA). Patients were classified into 3 groups based on postoperative pivot-shift and Lachman test findings: group I, both negative; group II, negative Lachman test and positive pivot shift; and group III, both positive. The radiographic analysis was performed via the angle between the tibial and femoral tunnels on plain anteroposterior radiographs, the angle between the tibial tunnel and anterior tibial cortex on the lateral view, and the femoral and tibial tunnel location by use of the ratio method. Postoperative knee MRI was performed, and the angle between the intercondylar anteroposterior axis and femoral tunnel on the axial view and the angle between the joint line and the graft on the oblique coronal and sagittal views were measured.

Results: There were 100 patients in group I, 13 in group II, and 24 in group III. Patients in group I showed the greatest improvement in Lysholm score among the groups, and patients in group III had the greatest side-to-side difference by KT-1000 arthrometer. Tunnel obliquity as measured by the angle between the anteroposterior axis of the femur and the femoral tunnel in the axial view on MRI was greater (P < .05) and the angle between the joint line and the graft on the oblique coronal view was less in group I.

Conclusions: This study showed a significantly lower Lysholm score and more vertical orientation of the femoral tunnel in the group with residual pivot shift than in the group without pivot shift. Vertical orientation of the femoral tunnel in the axial plane is closely related to residual pivot shift without definite anteroposterior laxity. More oblique positioning of the graft may have advantages in rotational stability, which in turn increase subjective patient satisfaction.

Level of evidence: Level III, diagnostic study of nonconsecutive patients without consistently applied reference gold standard.

Objective: To test an intra-articular reconstruction of the anterior cruciate ligament of the knee in 10 human cadavers by replacing 2 anterior cruciate ligament bundles, with the purpose of producing a surrogate that would be structurally more similar to the anatomy of the anterior cruciate ligament and would provide the knee with more stability.

Methods: We reconstructed the anteromedial and posterolateral bundles using a quadriceps muscle tendon graft that included a patellar bone segment. The anteromedial bundle was replaced in 10 knees (5 right and 5 left knees from different cadavers) by a quadriceps-bone tendon graft, and the anteromedial and posterolateral bundles were replaced in the matching pairs of these knees. In the latter, the bone segment was fixed to the tibia, and the tendinous portion of the graft was divided longitudinally creating two 5-mm wide bundles that were inserted individually into the femur through 2 independent bone tunnels. Then, the knees were tested mechanically to evaluate the tibial anterior dislocation in relation to the femur, as well as the rigidity of the graft. The control group was formed by the knees with intact anterior cruciate ligaments, before being resected to be reconstructed.

Results: The results obtained did not show superiority of double-bundle reconstruction over single-bundle reconstruction, and neither technique provided the knee with the same stability and rigidity of the intact anterior cruciate ligament.

Conclusion: Our hypothesis, based on the anatomy and biomechanics of the knee, that reconstruction of the anterior cruciate ligament using 2 bundles would result in a more anatomic reconstruction and provide better containment of the anterior tibial translation was not supported by the results of this study.

Surgical procedures for double-bundle anterior cruciate ligament reconstruction, which currently use hamstring graft, have been described, but some concerns remain regarding graft fixation and the ability to obtain adequate bundle size. We report an original double-bundle anterior cruciate ligament reconstruction technique using a quadriceps tendon graft and a simplified outside-in femoral tunnel-drilling process. The graft consists of a patellar bone block with its attached tendon split into superior and inferior portions, which yields 2 bundles. The anteromedial tunnel is drilled from the outside through a small lateral incision by use of a guide. The posterolateral tunnel is made through the same incision with a specific guide engaged in the anteromedial tunnel. A single tibial tunnel is created. The graft is routed from the tibia to the femur with the bone block in the tibial tunnel and the 2 bundles in their respective femoral tunnels. After fixation of the bone block in the tibia, the 2 bundles are tensioned and secured separately in their femoral tunnels.

Surgical reconstruction of the anterior cruciate ligament (ACL) is indicated in the ACL-deficient knee with symptomatic instability and multiple ligaments injuries. In the present study, we describe the clinical results of quadriceps tendon-patellar bone autograft for ACL reconstruction. From 1996 to 1998, the graft has been used in 38 patients. Thirty-four patients with complete final follow-up for 4-7 years were analyzed. The average follow-up time was 62 (48-84) months. Thirty-two patients (94%) achieved good or excellent results by Lysholm knee rating. Twenty-six patients (76%) could return to moderate or strenuous activity after reconstruction. Twenty-eight patients (82%) had ligament laxity of less than 2 mm. Finally; 31 patients (91%) were assessed as normal or nearly normal rating by IKDC guideline. Twenty-five patients (73%) had less than 10 mm difference in thigh girth between their reconstructed and normal limbs. Thirty-two (94%) and 31 (91%) patients could achieve recovery of the extensor and flexor muscle strength in the reconstructed knee to 80% or more of normal knee strength, respectively. A statistically significant difference exists in thigh girth difference, extensor strength ratio, and flexor strength ratio before and after reconstruction. Tunnel expansion with more than 1 mm was identified in 2 (6%) tibial tunnels. Our study revealed satisfactory clinical subjective and objective results at 4-7 years follow-up. Quadriceps tendon autograft has the advantage of being self-available, relatively easier arthroscopic technique, and having a suitable size, making it an acceptable graft choice for ACL reconstruction. There is little quadriceps muscle strength loss after quadriceps harvest. A quadriceps tendon-patellar autograft is an adequate graft choice to ACL reconstruction.

Tears of the anterior cruciate ligament in skeletally immature patients were operated with four different methods and their outcome compared to each other. Sixty-eight patients (33 males, 35 females), mean 12.5 years, were treated in four different centers from 1984 to 2001. Twenty-eight patients underwent the ACL-reconstruction with hamstring grafts, 16 patients with bone-patella-bone autografts, 12 patients with quadriceps grafts and 12 patients with facia lata. The mean follow-up was 32 months. Postoperative evaluation included radiographs, KT-1000/2000 stability measurements, Lysholm score, The Tegner activity scale and IKDC score. Neither leg length discrepancy nor angular deformities were noted. Mean KT-1000 difference was 2.1 mm, mean postoperative Lysholm knee score 93.3, IKDC 87% normal or nearly normal. The Tegner index decreased from 6.6 to 5.7. In total, six patients developed instability due to an adequate trauma 1 year after the index operation. Two patients showed mild arthrotic changes. All but two patients were able to return to the same level of preoperative sports participation. None of the four methods studied showed major differences in outcome compared to the other. No growth disturbance could be noted.

Recently, the interest in anatomic anterior cruciate ligament (ACL) reconstruction with double-bundle technique has increased so as to reproduce the original load distribution and kinematics of the knee. We developed an arthroscopic double-bundle ACL reconstruction technique using autogenous quadriceps tendon with 2 split grafts and a patellar bone plug. The anteromedial bundle and posterolateral bundle of the ACL are replicated with each split graft of quadriceps tendon and fixed with biodegradable interference screws on the 2 femoral tunnels. The patellar bone plug of the quadriceps tendon is fixed with a biodegradable interference screw within the 1 tibial tunnel. We suggest that our technique using quadriceps tendon may be an alternative in arthroscopic double-bundle ACL reconstruction.

Introduction: Press-fit fixation of bone-patellar tendon-bone (BPTB) grafts in anterior cruciate ligament (ACL) reconstruction has been analyzed biomechanically in previous studies; however, the use of quadriceps tendon-patellar bone (QTPB) grafts has not been studied so far. It is hypothesized that QTPB grafts provide primary fixation strength comparable to BPTB grafts in press-fit ACL reconstruction with respect to bone plug length and loading angle.

Materials and methods: Fifty-two QTPB grafts were harvested from fresh human cadaver knees (mean age 73.3 years) with the length of the patellar bone plug being either 15 mm (Group I) or 25 mm (Group II). The grafts were anchored within fresh porcine femora (mean age 12 months) using a press-fit fixation technique. Forty-eight specimens were loaded to failure at 10 mm/s with varying loading angles of 0 degrees , 30 degrees , and 60 degrees until failure. A microradiographic pre-post-implantation analysis was conducted on four grafts.

Results: The biomechanical testing showed a significant difference in the ultimate failure loads comparing Group I (mean 224+/-79.3 N) to Group II (mean 339+/-61.4 N), both showing mean ultimate failure loads to increase with rising loading angle. The predominant mode of failure was graft pullout at axial loading and tendon rupture at 60 degrees loading angle. The microradiographic analysis revealed an iatrogenic damage of the bone-tendon junction on the cancellous aspect of the bone plug in all trials, corresponding with the site of impactor placement during implantation.

Conclusion: QTPB grafts provide a loading capability comparable to BPTB grafts in press-fit ACL reconstruction. The broad and profound area of quadriceps tendon attachment to the patellar bone plug makes graft implantation demanding.

Anterior cruciate ligament surgery and rehabilitation have changed drastically during the past 30 years. The patellar tendon autograft fixed with buttons provides tight bone-to-bone placement of the graft and quick bony healing, which allows accelerated rehabilitation to obtain full range of motion and strength. Although surgical stability is easily reproducible, long-term patient satisfaction is difficult to guarantee. Full knee range of motion should be compared to that of the contralateral normal knee, including full hyperextension. We followed the progress of all patients to gauge the utility of our rehabilitation program. In order of importance, the lack of normal knee range of motion (within 2 degrees extension and 5 degrees of flexion compared with that of the normal knee), partial or total medial meniscectomy, partial or total lateral meniscectomy, and articular cartilage damage were related to lower subjective scores. Rehabilitation after ACL reconstruction must first strive to achieve full symmetrical knee range of motion before aggressive strengthening can begin. Our current perioperative rehabilitation starts at the time of injury and preoperatively includes aggressive swelling reduction, hyperextension exercises, gait training, and mental preparation. Goals after surgery are to control swelling while regaining full knee range of motion. After quadriceps strengthening goals are reached, patients can shift to sport-specific exercises. When using a graft from the contralateral knee, the conflicting goals of strengthening the donor site and achieving full knee range of motion are divided between the knees. Thus, normal range of motion and strength can be achieved more easily and more quickly than when using an ipsilateral graft. Regardless of the graft source, a systematic rehabilitation program that emphasizes the return to symmetrical knee motion, including hyperextension, is necessary to achieve the optimum result.

Introduction: Press-fit fixation of bone-patellar tendon-bone (BPTB) grafts in anterior cruciate ligament (ACL) reconstruction has been analyzed biomechanically in previous studies; however, the use of quadriceps tendon-patellar bone (QTPB) grafts has not been studied so far. It is hypothesized that QTPB grafts provide primary fixation strength comparable to BPTB grafts in press-fit ACL reconstruction with respect to bone plug length and loading angle.

Materials and methods: Fifty-two QTPB grafts were harvested from fresh human cadaver knees (mean age 73.3 years) with the length of the patellar bone plug being either 15 mm (Group I) or 25 mm (Group II). The grafts were anchored within fresh porcine femora (mean age 12 months) using a press-fit fixation technique. Forty-eight specimens were loaded to failure at 10 mm/s with varying loading angles of 0 degrees , 30 degrees , and 60 degrees until failure. A microradiographic pre-post-implantation analysis was conducted on four grafts.

Results: The biomechanical testing showed a significant difference in the ultimate failure loads comparing Group I (mean 224+/-79.3 N) to Group II (mean 339+/-61.4 N), both showing mean ultimate failure loads to increase with rising loading angle. The predominant mode of failure was graft pullout at axial loading and tendon rupture at 60 degrees loading angle. The microradiographic analysis revealed an iatrogenic damage of the bone-tendon junction on the cancellous aspect of the bone plug in all trials, corresponding with the site of impactor placement during implantation.

Conclusion: QTPB grafts provide a loading capability comparable to BPTB grafts in press-fit ACL reconstruction. The broad and profound area of quadriceps tendon attachment to the patellar bone plug makes graft implantation demanding.

Study design: Case report.

Objectives: To present a progressively increasing negative-work exercise program via eccentric ergometry early after anterior cruciate ligament reconstruction (ACL-R) and to suggest the potential of negative work to amplify the return of quadriceps size and strength.

Case description: The patient was a 26-year-old highly active recreational athlete who sustained an ACL tear while skiing in January 2004 and then again while skiing in February 2005. This individual underwent an arthroscopically assisted ACL-R with a double-loop semitendinosusgracilis autograft initially, then a patellar tendon autograft following his ACL graft rupture. Beginning within 3 weeks after surgery, a progressive negative-work exercise program was initiated using an eccentric ergometer. The patient completed 31 training sessions of 5 to 30 minutes in duration over a 12-week period following the ACL-R and 33 training sessions of the same frequency and duration following the ACL revision.

Outcomes: Following ACL-R, quadriceps volume increased 28% (involved lower extremity) and 14% (uninvolved lower extremity) during the 12-week training program. Following revision, quadriceps volume returned to similar levels at the same postoperative period as those achieved after the initial surgery (2% less on the involved side and 2% greater on the uninvolved side). Quadriceps strength, 15 weeks after ACL-R, exceeded preoperative measures by an average of 20% (involved) and 14% (uninvolved). Quadriceps strength after ACL revision exceeded all previous measures.

Discussion: This case report suggests that if gradually and progressively applied, negative work via eccentric ergometry can be both safe and efficacious early after ACL-R. Eccentric exercise may mitigate the prevalent muscle size and strength deficits commonly observed after ACL-R. The results of this case suggest a need for continued research with early negative work interventions following ACL-R.

Background: The quadriceps tendon is a viable graft source for revision anterior cruciate ligament reconstruction.

Purpose: To determine the functional results and graft failure rates in knees in which the patellar tendon had been previously harvested or was unavailable, expanded tunnels precluded the use of a semitendinosus-gracilis graft, or patients requested autogenous tissues instead of allografts for revision reconstruction.

Study design: Case series; Level of evidence, 4.

Methods: The authors observed 21 patients for a mean of 49 months postoperatively after revision anterior cruciate ligament reconstruction with a quadriceps tendon graft. The results were determined by KT-2000 arthrometer testing, the Cincinnati Knee Rating System, and the International Knee Documentation Committee Rating System. Fifteen knees required a concurrent procedure, including reconstruction of posterolateral structures in 5 knees, meniscal repairs in 5 knees, and high tibial osteotomy in 2 knees.

Results: Significant improvements occurred in symptoms (P < .0001), daily activities (P < .05), sports activities (P < .01), and the overall rating scores (P < .0001). Eighteen patients rated their knee condition as improved. Total mean anterior-posterior displacements decreased from 8.4 +/- 3.1 mm preoperatively to 2.0 +/- 2.3 mm at follow-up (P < .001). On the International Knee Documentation Committee knee ligament rating, 17 knees were graded as normal or nearly normal, 3 were graded as abnormal, and 1 was graded as severely abnormal.

Conclusion: The revision operation provided reasonable results in this group of complex knees. However, the functional and overall results were inferior to those reported for primary anterior cruciate ligament reconstruction. Many knees (90%) had compounding problems of articular cartilage damage, meniscectomy, varus malalignment, or additional ligamentous injury that most likely affected the results.

Sixty-four patients with three different autografts were prospectively evaluated following anterior cruciate ligament (ACL) reconstruction for motion return, thigh girth, quadriceps activity, assistive device usage, and duration of pain medication usage. The quadriceps tendon group achieved knee extension sooner than the patellar tendon group. The hamstring group used assistive devices for less time than the patellar tendon group. The quadriceps group required less pain medication than either of the groups. There are significant differences in short-term pain medication requirements and restoration of function among patients following ACL reconstruction using different autografts.

Purpose: To evaluate the cause of recurrent pathologic instability after anterior cruciate ligament (ACL) surgery and the effectiveness of revision reconstruction using a quadriceps tendon autograft using a 2-incision technique.

Type of study: Retrospective follow-up study.

Methods: Between 1999 and 2001, 31 patients underwent ACL revision reconstruction because of recurrent pathologic instability during sports or daily activities. Twenty-eight patients were reviewed after a mean follow-up of 4.2 years (range, 3.3 to 5.6 years). The mean age at revision surgery was 27 years (range, 18 to 41 years). The average time from primary procedure to revision surgery was 26 months (range, 9 to 45 months). A clinical, functional, and radiographic evaluation was performed. Also magnetic resonance imaging (MRI) or computed tomography (CT) scanning was performed. The International Knee Documentation Committee (IKDC), Lysholm, and Tegner scales were used. A KT-1000 arthrometer measurement (MEDmetric, San Diego, CA) by an experienced physician was made.

Results: Of the failures, 79% had radiographic evidence of malposition of their tunnels. In only 6 cases (21%) was the radiologic anatomy of tunnel placement judged to be correct on both the femoral and tibial side. The MRI or CT showed, in 6 cases, a too-centrally placed femoral tunnel. After revision surgery, the position of tunnels was corrected. A significant improvement of Lachman and pivot-shift phenomenon was observed. In particular, 17 patients had a negative Lachman test, and 11 patients had a grade I Lachman with a firm end point. Preoperatively, the pivot-shift test was positive in all cases, and at last follow-up in 7 patients (25%) a grade 1+ was found. Postoperatively, KT-1000 testing showed a mean manual maximum translation of 8.6 mm (SD, 2.34) for the affected knee; 97% of patients had a maximum manual side-to-side translation <5 mm. At the final postoperative evaluation, 26 patients (93%) graded their knees as normal or nearly normal according to the IKDC score. The mean Lysholm score was 93.6 (SD, 8.77) and the mean Tegner activity score was 6.1 (SD, 1.37). No patient required further revision. Five patients (18%) complained of hypersensitive scars from the reconstructive surgery that made kneeling difficult.

Conclusions: There were satisfactory results after ACL revision surgery using quadriceps tendon and a 2-incision technique at a minimum 3 years’ follow-up; 93% of patients returned to sports activities.

Level of evidence: Level IV, case series, no control group.

Purpose: Free tendon grafts for reconstruction of the anterior cruciate ligament have become more prevalent with the desire for reduced morbidity, earlier postoperative rehabilitation, and improved free tendon graft fixation. The central quadriceps tendon autograft is an alternative to bone-patellar tendon-bone and free hamstring autografts. The purpose of this study was to measure the postharvest reduction in quadriceps extensor mechanism strength when a central quadriceps free tendon graft is removed. The strength deficit was compared with that associated with harvesting a central free patellar tendon graft, excluding the effects of harvesting bone blocks.

Type of study: Experimental laboratory study.

Methods: Fourteen knee extensor mechanisms were divided into quadriceps and patellar tendon constructs. Constructs were tested to failure in tension in either the intact state or after removing 10-mm wide central free tendon grafts. Failure strengths of the quadriceps and patellar tendon constructs were compared statistically using paired and unpaired t tests.

Results: The average strength (+/-SD) measured for the native quadriceps tendon was 3,660 +/- 830 N, decreasing to 2,430 +/- 680 N after removing a partial-thickness 10-mm wide central free graft. The average strength measured for the native patellar tendon was 1,920 +/- 330 N, decreasing to 1,460 +/- 740 N after removing a 10-mm wide central free graft.

Conclusions: The tensile strength of the quadriceps tendon is reduced by approximately one third after harvesting a partial-thickness 10-mm wide central free tendon graft. This postharvest strength of the quadriceps tendon is higher than that of the intact patellar tendon.

Clinical relevance: Surgeons can be assured that harvest of a central quadriceps free tendon graft leaves a stronger extensor mechanism than harvest of a patellar tendon graft.

Background: Because of health care funding and policy changes, there is a need to examine the effects of an evolution toward patient-directed (ie, home-based) rehabilitation programs on clinical outcomes of patients undergoing anterior cruciate ligament reconstruction.

Hypothesis: There will be no difference in the effectiveness of a home-based rehabilitation program and a standard physical therapy-supervised rehabilitation program in patients 3 months after nonacute anterior cruciate ligament reconstruction with bone-patellar tendon-bone grafts.

Study design: Randomized controlled clinical trial; Level of evidence, 1.

Methods: There were 145 patients (16-59 years) who attended a presurgery education class. Home-based patients attended 4 physical therapy sessions, and physical therapy-supervised patients attended 17 physical therapy sessions over the first 12 weeks after surgery. All patients followed the same standardized rehabilitation program. Study outcome measures included active-assisted knee flexion and passive knee extension range of motion, knee range of motion during walking, KT computerized arthrometer results, and isokinetic quadriceps and hamstrings strength. Patient outcomes were dichotomized as either clinically acceptable or unacceptable. Rehabilitation programs were compared by the proportion of acceptable patients in each group.

Results: The home-based group had a significantly higher percentage of patients with acceptable flexion and extension range of motion compared to the standard physical therapy group (flexion, 67% vs 47%; extension, 97% vs 83%). There were no significant differences between the groups in range of motion during walking, ligament laxity, and strength.

Conclusion: A structured, minimally supervised rehabilitation program was more effective in achieving acceptable knee range of motion in the first 3 months after anterior cruciate ligament reconstruction than a standard physical therapy-based program.

Clinical relevance: Recreational athletes undergoing nonacute anterior cruciate ligament reconstruction can successfully reach acceptable rehabilitation goals in the first 3 months after surgery with a limited number of purposeful physical therapy education sessions, allowing recreational athletes more flexibility when integrating the necessary postoperative rehabilitation into their daily activities.

We describe a technique for arthroscopic anterior cruciate ligament (ACL) reconstruction using the middle third of the quadriceps tendon without a patellar bone block and absorbable tibial and femoral cross-pin fixation. The central part of the quadriceps tendon is harvested through a 5-cm long anterior skin incision without a patellar bone block. Tibial and femoral tunnels are prepared, the graft is passed up the tunnels, and is fixed both in the femur and the tibia using absorbable cross pins (Rigid Fix; Mitek, Johnson & Johnson, Norwood, MA). In this way, the graft is stabilized near the joint line, providing outlet fixation. In our practice, very good results have been obtained with the use of this technique.

Purpose: The purpose of this study was to determine the outcome of anterior cruciate ligament (ACL) reconstruction using a quadriceps tendon autograft.

Type of study: A case series of patients who had received arthroscopic ACL reconstructions using quadriceps tendon autograft was retrospectively evaluated.

Methods: Sixty-seven ACL reconstructions were evaluated at a mean of 41 months (range, 27 to 49 months). Clinical assessment was made using a modified Lysholm score, documentation of International Knee Documentation Committee (IKDC), the anterior knee pain questionnaire of Shelbourne and Trumper, and by KT-2000 arthrometric analysis. Isokinetic strength testing and radiographic assessments were also performed.

Results: Arthrometric analysis showed that 63 knees (94%) were graded A or B with a median laxity of 2 mm postoperatively. The Lysholm score improved postoperatively from 71 to 90 ( P < or = .05). Extension peak torque of the quadriceps muscle recovered to 82% and 89% of that of the contralateral knee at 180 degrees/second at 1 year and 2 years after surgery, respectively. The patellar position in terms of congruence angle and Insall-Salvati ratio did not show any significant change. Only 4 patients complained of moderate pain on kneeling and 1 patient complained of harvest-site tenderness.

Conclusions: ACL reconstruction using a quadriceps tendon autograft showed satisfactory results with reduced donor-site morbidities. The quadriceps tendon can be a reliable source of graft, and is comparable to bone-patellar tendon-bone or hamstring tendon in ACL reconstruction.

Level of evidence: Level IV, Case Series (no, or historical, control group).

Aim: The goal of this prospective randomized study was to compare the isokinetic recovery of thigh strength after anterior cruciate ligament (ACL) reconstruction by using patellar or quadriceps tendon as graft at the 6th month follow-up.

Methods: The authors evaluated 48 patients who underwent arthroscopic ACL reconstruction using patellar tendon (PT group) or quadriceps tendon (QT group) as autograft after a 6 months follow-up undergoing the following tests: the Ergojump Bosco System springboard and Universal’s FITNET computerized isokinetic system.

Results: The counter movement jump (CMJ) test showed a 24% (p<0.01) strength deficit in patients operated with patellar tendon and 11% in the quadriceps tendon group. Also in the leg press test the greater differences in strength (p<0.05) were verified in the patellar tendon group, above all the peak torque (PT) test carried out at 3 repetitions (15%).

Conclusions: The strength deficit found in the subjects operated with quadriceps tendon were statistically lower in comparison to that verified in the patellar tendon group. A good recovery in thigh strength after 6 months in patients operated with quadriceps tendon could encourage the use of this kind of graft in order to achieve an easier rehabilitation and a faster release of the patient to daily and sports activity.

CQFT ACL reconstruction yields a stable, highly functional knee with little associated morbidity. Patient satisfaction has been very high, and objective follow-up data collected thus far is very encouraging.

Purpose: The purpose of this study was to use current fixation techniques and compare the stiffness and ultimate tensile failure of the tendinous end of the quadriceps tendon (QT) with the bone plug end of the bone-patellar tendon-bone (BPTB) graft using current techniques of fixation.

Type of study: Randomized trial of elderly cadaver knees.

Materials and methods: Tibial and femoral biodegradable interference fixation and femoral EndoButton (Smith & Nephew, Acufex, Mansfield, MA) fixation in bone tunnels with the QT and the BPTB graft were compared by using 10 pairs of elderly cadavers and biomechanical testing. Two groups, fixation at time zero (simulating fixation in the operating room) and testing after 1, 000 loading cycles (simulating patient rehabilitation exercises), were used.

Results: At time zero fixation, stiffness of the soft tissue QT tibial tunnel interference fixation was 59% less stiff than the stiffness of the interference fixation of a BPTB plug in a femoral tunnel (P =.11). The EndoButton femoral fixation resulted in a decrease in stiffness at time zero compared with femoral tunnel interference fixation of the soft tissue QT (P =.03). All groups improved stiffness with cycling the construct to 1,000 cycles.

Conclusions: Placement of the QT tendinous end of the graft in the femoral bone tunnel when using a interference fixation will approximate the stiffness of a bone plug in the tibial bone tunnel with interference fixation. The EndoButton fixation is not as stiff as either of the femoral interference fixation options. The addition of more than 20 loading cycles could remove laxity from the graft fixation-graft cruciate ligament complex and improve its stiffness.

Purpose: The purpose of this study was to use current fixation techniques and compare the stiffness and ultimate tensile failure of the tendinous end of the quadriceps tendon (QT) with the bone plug end of the bone-patellar tendon-bone (BPTB) graft using current techniques of fixation.

Type of study: Randomized trial of elderly cadaver knees.

Materials and methods: Tibial and femoral biodegradable interference fixation and femoral EndoButton (Smith & Nephew, Acufex, Mansfield, MA) fixation in bone tunnels with the QT and the BPTB graft were compared by using 10 pairs of elderly cadavers and biomechanical testing. Two groups, fixation at time zero (simulating fixation in the operating room) and testing after 1, 000 loading cycles (simulating patient rehabilitation exercises), were used.

Results: At time zero fixation, stiffness of the soft tissue QT tibial tunnel interference fixation was 59% less stiff than the stiffness of the interference fixation of a BPTB plug in a femoral tunnel (P =.11). The EndoButton femoral fixation resulted in a decrease in stiffness at time zero compared with femoral tunnel interference fixation of the soft tissue QT (P =.03). All groups improved stiffness with cycling the construct to 1,000 cycles.

Conclusions: Placement of the QT tendinous end of the graft in the femoral bone tunnel when using a interference fixation will approximate the stiffness of a bone plug in the tibial bone tunnel with interference fixation. The EndoButton fixation is not as stiff as either of the femoral interference fixation options. The addition of more than 20 loading cycles could remove laxity from the graft fixation-graft cruciate ligament complex and improve its stiffness.

Rupture of the anterior cruciate ligament (ACL) typically leads to surgical reconstruction followed by an extensive rehabilitation program. One of the most commonly experienced complications associated with ACL rupture and reconstruction is quadriceps muscle atrophy. A clear understanding of the exact mechanisms associated with ACL related atrophy remains undocumented. The purpose of the present study was to investigate maximum H-reflex to maximum M-wave ratio as well as quadriceps deficit for both isometric and isokinetic peak torques in a post ACL reconstruction population. Forty subjects volunteered for participation in this study. The experimental group comprised 20 subjects who had undergone patellar tendon graft reconstruction of a torn ACL. A matched control group of 20 subjects were also measured for comparative purposes. The results indicated the control group had significantly higher quadriceps to quadriceps ratio than did the ACL group [t(38) = 9.05 p < .001]. In contrast, there was no difference in the H-max/M-max ratio for either group or leg. The strength findings of this study support previous findings. The spinal reflex results support the need for additional research in this area, specifically with more acutely injured subjects.

The aim of the present study was to quantify the amount of antagonist coactivation and the resultant moment of force generated by the hamstring muscles during maximal quadriceps contraction in slow isokinetic knee extension. The net joint moment at the knee joint and electromyographic (EMG) signals of the vastus medialis, vastus lateralis, rectus femoris muscles (quadriceps) and the biceps femoris caput longum and semitendinosus muscles (hamstrings) were obtained in 16 male subjects during maximal isokinetic knee joint extension (KinCom, ROM 90-10 degrees, 30 degrees x s(-1)). Two types of extension were performed: [1] maximal concentric quadriceps contractions and [2] maximal eccentric hamstring contractions Hamstring antagonist EMG in [1] were converted into antagonist moment based on the EMG-moment relationships determined in [2] and vice versa. Since antagonist muscle coactivation was present in both [1] and [2] a set of related equations was constructed to yield the moment/EMG relationships for the hamstring and quadriceps muscles, respectively. The equations were solved separately for every 0.05 degrees knee joint angle in the 90-10 degrees range of excursion (0 degrees = full extension) ensuring that the specificity of muscle length and internal muscle lever arms were incorporated into the moment/EMG relationships established. Substantial hamstring coactivation was observed during quadriceps agonist contraction. This resulted in a constant level of antagonist hamstring moment of about 30 Nm throughout the range of motion. In the range of 30-10 degrees from full knee extension this antagonist hamstring moment corresponded to 30-75% of the measured knee extensor moment. The level of antagonist coactivation was 3-fold higher for the lateral (Bfcl) compared to medial (ST) hamstring muscles The amount of EMG crosstalk between agonist-antagonist muscle pairs was negligible (Rxy2<0.02-0.06). The present data show that substantial antagonist coactivation of the hamstring muscles may be present during slow isokinetic knee extension. In consequence substantial antagonist flexor moments are generated. The antagonist hamstring moments potentially counteract the anterior tibial shear and excessive internal tibial rotation induced by the contractile forces of the quadriceps near full knee extension. In doing so the hamstring coactivation is suggested to assist the mechanical and neurosensory functions of the anterior cruciate ligament (ACL).

We analyzed mechanical tensile properties of 16 10-mm wide, full-thickness central parts of quadriceps tendons and patellar ligaments from paired knees of eight male donors (mean age, 24.9 years). Uniaxial tensile testing was performed in servohydraulic materials testing machine at an extension rate of 1 mm/sec. Sixteen specimens were tested unconditioned and 16 specimens were tested after cyclic preconditioning (200 cycles between 50 N and 800 N at 0.5 Hz). Mean cross-sectional areas measured 64.6 +/- 8.4 mm2 for seven unconditioned and 61.9 +/- 9.0 mm2 for eight preconditioned quadriceps tendons and were significantly larger than those values of seven unconditioned and seven preconditioned patellar ligaments (36.8 +/- 5.7 mm2 and 34.5 +/- 4.4 mm2, respectively). Mean ultimate tensile stress values of unconditioned patellar ligaments were significantly larger than those values of unconditioned quadriceps tendons: 53.4 +/- 7.2 N/mm2 and 33.6 +/- 8.1 N/mm2, respectively. Strain at failure was 14.4% +/- 3.3% for preconditioned patellar ligaments and 11.2% +/- 2.2% for preconditioned quadriceps tendons (P = 0.0428). Preconditioned patellar ligaments exhibited significantly higher elastic modulus than preconditioned quadriceps tendons. Based on mechanical tensile properties analyses, the quadriceps tendon-bone construct may represent a versatile alternative graft in primary and revision anterior and posterior cruciate ligament reconstruction.

Eighty-three patients with ACL reconstructions using the quadriceps patellar tendon graft were evaluated in a 10 year (mean, 5.5 years) follow-up study. A five-part analysis, consisting of physical examination, questionnaire, Genucom analysis, operative note review, and radiographs, was performed. Seventy-six percent were categorized as satisfactory. Ninety-two percent were content with their results, while only 4% were unsatisfied. Ninety-three percent of the patients had no significant pain and 95% had no giving way postreconstruction. Ninety-two percent had no more than a mild functional deficit. Eighty-seven percent and 90% of the patients had no significant Lachman or pivot shift by examination, respectively. Our results showed no increase in failure over time (1 to 10 years), although those operated on during the initial 5 years showed more radiographic degenerative changes. Plotting our results in classification systems of other authors yielded success rates as good as or better than those using our own criteria. An objective means by which to quantify laxity did not reliably correlate with the quantifying of laxity made by physical examination. Only the lack of a formal rehabilitation program greater than 4 months postoperatively and repaired tears of the medial or lateral collateral ligaments proved to be significant risk factors for poor recovery.

Both primary repair and late substitution of anterior cruciate ligaments can be accomplished by intra-articular methods. This principle is to provide temporary struts that are initially avascular but can later undergo revascularization and metaplasia to form a new ligament. The graft does afford initial support, however. An understanding of anatomic principles, suture placement, freedom of graft from impingement, avoidance of acute angular deviation of the graft, solid static stability, anatomic attachment points, and blood supply, is absolutely essential for success in this field of surgery.