Biomechanics Research Today is a free monthly online journal that collates and summarizes the latest research about Biomechanics, including details on mechanics of living organisms, movement, locomotion, prosthetic limbs.

Factors associated with decreased muscle strength after anterior cruciate ligament reconstruction with hamstring tendon grafts.

Goradia VK, Grana WA, Pearson SE

Goradia Orthopedics and Sports Medicine, Midlothian, Virginia, USA. vic@goOrtho.net

PURPOSE: To identify factors associated with decreased muscle strength and activity after anterior cruciate ligament (ACL) reconstruction with semitendinosus-gracilis tendon (ST-G) grafts. TYPE OF STUDY: Retrospective review. METHODS: Eighty-five patients who underwent ACL reconstruction with ST-G grafts were evaluated at a mean of 44.4 months after surgery. Patients underwent isokinetic testing, physical examination, radiographs, instrumented laxity testing, and Lysholm, Cincinnati, and International Knee Documentation Committee (IKDC) ratings. Cartilage and meniscal pathology at surgery was reviewed. Strength group 1 (n = 30) showed greater than 20% deficits in strength; strength group 2 (n = 55) had less than 20% strength deficits. Activity group 1 (n = 60) maintained their IKDC activity level at final follow-up relative to preinjury level; activity group 2 (n = 25) decreased activity by 1 or more levels. RESULTS: With all patients combined, there was less than a 4% difference in mean hamstring and quadriceps strength between the reconstructed and contralateral legs at follow-up. Knee flexion deficits were associated with decreased hamstring strength. Subjective giving way and squatting/kneeling discomfort were associated with decreased quadriceps strength. Patients in strength group 1 were more likely to have squatting/kneeling discomfort and lower Cincinnati Function scores. Activity group 2 had a longer interval from injury to surgery and more chondromalacia at surgery. At follow-up, activity group 2 had lower subjective scores and was more likely to have pain, swelling, giving way, and flexion deficits. Activity group 2 also had greater deficits in quadriceps strength. CONCLUSIONS: Articular cartilage injury and meniscal pathology were not associated with decreased muscle strength. ACL reconstruction with ST-G grafts has a 38% incidence of squatting/kneeling pain that occurs secondary to patellofemoral crepitus, harvest site symptoms, and tibial hardware sensitivity. LEVEL OF EVIDENCE: Level IV, therapeutic, case series, no control group.

Published 9 January 2006 in Arthroscopy, 22(1): 80.
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