RESUMO
INTRODUCTION: After undergoing anterior cruciate ligament (ACL) reconstruction, patients must recover at least 80% of their hamstring and quadriceps strength to be able to return to sports without risk to the graft. Harvesting of the patellar tendon leads to large deficits in quadriceps strength, while harvesting the hamstring tendons leads to large deficits in hamstring strength. However, there are no published studies on the strength deficit after ACL reconstruction with the fascia lata. The objective of this study was to evaluate the results of isokinetic testing in patients who underwent ACL reconstruction with a fascia lata graft and to analyze the individual factors affecting these results. The hypothesis was that preserving the quadriceps and hamstrings would lead to satisfactory isokinetic testing results by preserving the physiological balance between the flexor and extensor mechanisms in the leg. MATERIALS AND METHODS: In this retrospective, single-center study, 53 patients had their quadriceps and hamstring strength recovery evaluated 6 months and 1 year post-ACL reconstruction by concentric isometric testing at a slow (90°/s) and fast velocity (240°/s). These results were analyzed as a function of individual characteristics such as age, sex, preinjury level and type of sports activity, and IKDC and Lysholm scores. RESULTS: The quadriceps strength deficit at the slow and fast velocities was 27.5% and 22.5% at 6 months and 15.5% and 11% at 1 year, respectively. The hamstring strength deficit at the slow and fast velocities was 12.1% and 7% at 6 months and 8% and 6.4% at 1 year, respectively. The quadriceps to hamstring ratio at the slow and fast velocities was 66.7±16.5 and 71.3±15.5 at 6 months, and 61.1±14.9 and 67.6±12.5 at 1 year. Being less than 25 years of age, having a subjective IKDC grade or Lysholm score above 90, and being a professional athlete were significant predictors of better muscle strength recovery. DISCUSSION: Isokinetic testing at 6 months and 1 year after ACL reconstruction surgery using the fascia lata showed that the quadriceps to hamstring ratio is close to physiological standards. LEVEL OF EVIDENCE: IV retrospective study.
