HAMSTRING MORPHOLOGY AND STRENGTH REMAIN ALTERED 2 YEARS FOLLOWING A HAMSTRING GRAFT IN ACL RECONSTRUCTION

Background:The hamstring graft used in anterior cruciate ligament (ACL) reconstruction has been shown to lead to changes to the semitendinosus and gracilis musculature. This study further evaluated the effect of the surgery on hamstring muscle morphology and knee muscle strength at 2 years post-surgery.Hypotheses:(1) Loss of donor muscle size would significantly correlate with knee muscle strength deficits (2) Loss of donor muscle size would be greater for muscles that do not experience tendon regeneration, and (3) Morphological adaptations would also be evident in non-donor knee muscles.Study Design:Cross sectional evaluation.Methods:20 participants (14 male, 6 female, 29 ± 7 years, 82 ± 15 kg) that had undergone a hamstring graft in ACL reconstruction at least two years previously, underwent bilateral MRI and subsequent strength testing. Muscle and tendon volumes, peak CSA’s and lengths were determined for 12 muscles and 6 functional muscle groups of the surgical and contralateral limbs. Peak isokinetic...