The effect of diagnostic and operative arthroscopy and open meniscectomy on muscle strength in the thigh.

In this study we measured the effect on the muscle strength in the thigh in connection with diagnostic arthroscopy with central approach, arthroscopy with arthroscopic operation of bucket-handle ruptures, flap tears, total arthroscopic meniscectomy, and open meniscectomy. Thirty-seven patients were tested preoperatively and 1, 4 and 8 weeks postoperatively with a Cybex II isokinetic dynamometer. The extensor muscles of the knee joint were most affected. The flexor muscles were generally recovered in all groups within a month. Diagnostic arthroscopy and arthroscopic operations for bucket-handle ruptures showed no significant effect on the thigh muscle torque. With the other arthroscopic operations there was a 40% decrease of quadriceps function 1 week after operation. After 8 weeks normal function returned. Open meniscectomy had a much more negative effect on the quadriceps muscle with a decrease of about 70% after 1 week. After 8 weeks, the rehabilitation was still not complete.