The knee has two crescent shaped shock absorbing cartilages, the menisci. The thin, tapered edge is susceptible to tears. The torn part can move in and out of the weight-bearing area and cause locking and/or catching of the joint, and pain. Most often, these tears do not heal spontaneously.
Treatment focuses on preservation of as much functional cartilage as possible, to maintain the shock absorbing function.
The torn, unstable, nonfunctional piece of cartilage is usually removed through a 2-3mm incision, using a variety of arthroscopic instruments. On occasion, the torn part is repairable. Particularly in young and/or athletic individuals, this should be carefully considered. The initial rehabilitation is slower than after removal of the torn part. It is anticipated that repair will lead to better results in the long run.
Meniscus surgery typically takes 30-45 minutes. After excision of the torn part, rehabilitation can be swift, only limited by discomfort. Most people use crutches for the first few days, walk fairly well by the end of the first week, and are ready to consider some exercise by two weeks. The knee remains somewhat painful with activity for several months. A "reminder" that surgery was performed!
After isolated meniscal repair, most often I ask to limit bending of the knee to 45 degrees for six weeks, to protect the repair. Weight-bearing can be initiated immediately.