Strength deficits and flexion range of motion following primary anterior cruciate ligament reconstruction differ between quadriceps and hamstring autografts

ObjectiveTo determine if anterior cruciate ligament (ACL) reconstruction with a quadriceps tendon (QT) could achieve faster postoperative recovery compared with hamstring tendon (HT) ACL reconstruction.MethodsThirty-seven QT patients were matched for gender, age and preinjury activity level with 74 HT patients. A 6-month postoperative assessment included standardised reported outcome measures: patient-reported outcome measures (PROMs) (International Knee Documentation Committee-subjective knee evaluation form, Knee injury and Osteoarthritis Outcome Score-knee related quality of life subscale, ACL-Return to Sport after Injury scale, Marx activity scale, anterior knee pain), range of motion (active, standing and passive), anterior knee laxity testing, hop tests (single and triple crossover hop for distance) and isokinetic strength testing of the knee extensors and flexors. T-tests or Mann Whitney U tests were used to compare data between groups.ResultsThere were no significant differences between the two groups for any of the PROMs. The HT group had reduced active and standing knee flexion range compared with the QT group (p<0.001). Isokinetic strength testing showed significant deficits in limb symmetry indices for both concentric hamstring peak torque at 60°/s (p<0.001) and 180°/s (p=0.01) in the HT group. There were significantly greater deficits in limb symmetry indices for concentric quadriceps peak torque at 60°/s (p<0.001) and 180°/s (p=0.001) in the QT group.ConclusionThe QT graft does not appear to offer a more rapid recovery in terms of knee symptoms or function which could have allowed for faster progression to the dynamic phases of rehabilitation.Level of evidenceLevel III.

The Influence of Exercise-Induced Fatigue on Inter-Limb Asymmetries: a Systematic Review

Background Non-contact injuries such as anterior cruciate ligament ruptures often occur during physical load toward the end of a match. This is ascribed to emerging processes due to exercise-induced fatigue. Moreover, non-contact injuries often occur during dynamic actions such as landing or cutting movements. Inter-limb asymmetries are suggested as one possible cause for those injuries based on findings indicating that asymmetries between limbs are associated with a higher injury risk. Hence, assessing inter-limb asymmetry during physical load in the condition of exercise-induced fatigue is warranted to identify potentially relevant precursors for non-contact injuries. Objective The objective of this study was to overview the current state of evidence concerning the influence of exercise-induced fatigue on inter-limb asymmetries through a systematic review. Methods A systematic literature search was conducted using the databases Web of Science, Scopus, PubMed, SURF, and SPONET to identify studies that assessed inter-limb asymmetries of healthy people, calculated with an asymmetry equation, before and after, or during a loading protocol. Results Thirteen studies were included in the systematic review. The loading protocols involved running, race walking, jumping, squatting, soccer, rowing, and combinations of different exercises. Moreover, different tasks/procedures were used to assess inter-limb asymmetries, e.g., squats, single-leg countermovement jumps, gait analysis, or isokinetic strength testing. The results seem to depend on the implemented loading protocol, the tasks/procedures, and the measured parameters. Conclusions Future research needs more systematization and consistency, assessing the effect of exercise-induced fatigue on inter-limb asymmetries. Moreover, the emergence of inter-limb asymmetries should be regarded in the context of sport-specific movements/tasks. Testing before, after, and during a physical loading protocol is advisable to consider the influence of exercise-induced fatigue on sport-specific tasks and to identify the possible mechanisms underlying load-dependent inter-limb asymmetries with regard to risk of non-contact injury.

RETURN TO PLAY ASSESSMENTS: RATES OF NEUROMUSCULAR ASYMMETRIES IN HEALTHY ADOLESCENT ATHLETES

Background: Return to play (RTP) assessments after ACL reconstruction attempt to identify patients with residual deficits that haven’t regained their preinjury function, in hopes of decreasing the high rate of reinjury in this population. However, the utility of common RTP assessments, including hop testing and Biodex isokinetic strength, remains to be better understood. In the adolescent population, RTP assessments commonly rely upon those used in adults with limited evidence. The purpose of the current study was to establish the performance of young healthy athletes on common RTP assessments. Methods: A prospective cohort study of 47 healthy athletes aged 12 to 16 years was performed. All athletes performed hop testing (4 components - single, triple, crossover and timed) and Biodex isokinetic strength (6 components - quadriceps and hamstring; 60, 180, 300 degrees/second). The results were compared to the contralateral leg with a deficit defined as greater than 10% less relative to the contralateral leg. Patient demographics including age, sex, BMI, and sport played, as well as the dominant and nondominant leg were recorded. Analysis was performed relative to a single extremity (total 94) to simulate the evaluation in the setting of ACL return to play. Results: A total of 17 males and 30 females were included, with 27 being 12-13 yo and 20 being 14-16 yo. Overall, at least one deficit was present in 61.7% of extremities. This was significantly more common in non-dominant (76.6%) than dominant (46.8%) extremities (p<0.001). Biodex isokinetic strength deficits were present in 55.3% of extremities, while hop testing deficits were present in 24.5% of extremities. A total of 17 extremities had deficits in both Biodex and hop testing, while 35 had isolated biodex deficits and 6 had isolated hop testing deficits. Biodex deficits were present for quadriceps strength in 18.1%, 7.4%, and 17.0% at 60, 180, and 300 degrees respectively, while deficits in hamstring strength were present in 27.7%, 11.7%, and 17.0% at 60, 180, and 300 degrees respectively. Hop testing deficits were present in 7.4% of single hop, 9.6% of triple hop, 9.6% of crossover hop, and 6.4% of timed hop testing. Conclusions: The current study demonstrates that asymmetries in strength and hop testing are common in adolescent healthy athletes. These deficits are more common for Biodex isokinetic strength testing than functional hop testing. Deficits are more likely to occur in the nondominant extremity.

6- VS 9-MONTH RETURN TO SPORT TESTING RESULTS AFTER ACL RECONSTRUCTION WITH QUADRICEPS AUTOGRAFT IN ADOLESCENT PATIENTS

Background: Recently, anterior cruciate ligament reconstruction (ACLR) using quadriceps tendon autograft has gained in popularity, particularly in adolescent patients. Studies are lacking that evaluate return to sport (RTS) testing after ACLR with quadriceps tendon autograft (QT). Hypothesis/Purpose: To investigate differences between the 6-month and 9-month RTS assessment in adolescent patients undergoing ACLR with QT. Methods: A retrospective review of adolescent patients who underwent primary ACLR with all soft-tissue QT identified 18 patients with formal RTS testing data at 6 and 9 months. Surgeries were performed between June 2017 and October 2018 by single surgeon using an all-inside technique. Concomitant meniscus repairs were performed in 38.9% of patients. All patients followed the same standardized rehabilitation protocol and completed a structured RTS test 6 and 9 months after surgery. The RTS test consisted of isometric and isokinetic strength testing, the Lower Quarter Y-Balance Test (YBT-LQ), and single-legged hop testing. The recovery of muscle strength, assessed via isometric/isokinetic and hop testing, was defined by a limb symmetry index (LSI) ≥ 90%. Differences were compared between the two RTS time points. Results: The mean age at the time of surgery was 15.2 years (range, 13-17 years). There were statistically significant improvements in the Pedi-IKDC (92.1 ± 8.4 vs. 82.9 ± 8.7; P = 0.001) and Tegner activity scale (7.1 ± 2 vs. 5.1 ± 2; P = 0.001). There were statistically significant improvements in isometric quadriceps strength (LSI, 82.6 ± 16.8 vs. 93.1 ± 11; P = 0.03) and hamstring strength (LSI, 86.4 ± 11.3 vs. 98.2 ± 9.6; P = 0.001). There were improvements in isokinetic knee extension at both 60 deg/sec (LSI, 75 ± 16.9 vs. 82.8 ± 13.9) and 180 deg/sec (LSI, 79.1 ± 14.8 vs. 84.6 ± 10.9), but the differences were not statistically significant ( P = 0.08 and P = 0.11, respectively). There were no significant differences in isokinetic testing of knee flexion at either 60 deg/sec or 180 deg/sec. There were no statistically significant differences in the anterior reach component of the YBT-LQ at 6 and 9 months. Patients demonstrated statistically significant improvements on single-legged hop testing with mean LSIs > 95% for each of the four tests at 9 months postop. Conclusion: Adolescent patients undergoing ACLR with QT demonstrated significant improvements in subjective function and quadriceps strength between 6 and 9 months postop. This data supports delaying RTS beyond 9 months in this at-risk population. [Table: see text]