Muscle strength recovery versus semitendinosus and gracilis tendon regeneration after harvesting for anterior cruciate ligament reconstruction.

Twenty consecutive, chronic and isolated anterior cruciate ligament (ACL) lesions that underwent reconstruction with quadrupled semitendinosus (ST) and gracilis (G) were prospectively examined to compare tendon regeneration and muscle strength recovery. Twenty consecutive axial nuclear magnetic resonance (NMR) scans were done after 1 month, 6 months and 2 years from surgery. A CybexII was used to evaluate concentric strength deficits both in flexion and in internal tibia rotation at 6 months and 2 years.