Recovery of muscle strength following arthroscopic meniscectomy.

The purpose of this study was to investigate the time course of spontaneous recovery (no supervised training) of muscle torques in the first 3 months postarthroscopic partial meniscectomy. This information will then be used to plan a clinical trial investigating the effects of rehabilitation following arthroscopic meniscectomy. Knee extensor and flexor strength was evaluated at four different velocities (60, 120, 180, and 240 degrees/sec) preoperatively and every 2 weeks from weeks 2-12 postsurgery. Eight subjects were evaluated on a Cybex II+ and 14 subjects were evaluated on a Cybex II isokinetic device. A repeated measures analysis of variance was used to determine possible side (involved and uninvolved), speed (60, 120, 180, and 240 degrees/sec), or time (preoperative, 2, 4, 6, 8, 10, and 12 weeks postoperatively) effects as well as possible interactions between these factors. Prior to partial meniscectomy, the involved quadriceps was significantly weaker than the uninvolved quadriceps only at 60 degrees/sec (15%). A further decrease in torque was noted at 2 (25-40% deficit depending on the velocity) and 4 weeks postsurgery at all speeds (17-25%). The quadriceps recovered to preoperative values by 4-6 weeks postsurgery and stabilized at this level until the end of the study, at which time the quadriceps remained weaker than the contralateral side at 60 degrees/sec (14%) and 120 degrees/sec (12%). Prior to surgery, the involved hamstrings were comparable with the uninvolved hamstrings. Although significant differences between sides were found at week 2 postsurgery at 60 (23%) and 120 degrees/sec (17%), the hamstrings were fully recovered by 4 weeks postoperatively. In conclusion, although the quadriceps may recover to preoperative levels by 4-6 weeks following partial meniscectomy, further recovery does not appear to be possible without training as the quadriceps remains weaker than the contralateral side up to 12 weeks postsurgery.