The meniscus is the soft rubbery bumper cushion that sits between the thigh bone and the leg bone. There are two menisci in the knee; a medial (inside) and a lateral (outside) meniscus. These structures act as shock absorbers that decrease the stress seen by the articular cartilage found on the end of the thigh bone and leg bone. Meniscus injuries are quite common and occur in patients of all ages. An injury can occur as a result of squatting, turning or twisting during almost any activity. Once the meniscus is torn, symptoms like locking, clicking, and catching may occur. In addition, patients will frequently notice swelling in the knee. The pain will be localized along the joint line on the inside or the outside of the knee depending on the tear. The diagnosis is made based upon a history and physical exam and frequently special tests. X-rays are usually normal. If there is some question regarding the diagnosis, an MRI can be obtained to confirm a tear. Most tears remain symptomatic and will ultimately require treatment if they interfere with activities of daily living or sports and recreation activities.
90% of the time, the appropriate treatment is arthroscopy to remove the torn fragments. Often the meniscus cannot be repaired due to the lack of blood supply, which prevents healing factors from getting to the area of injury even when repaired by stitches. Arthroscopic meniscal debridement is one of the most common procedures performed in orthopedics. It is typically very successful in decreasing symptoms and allowing patients to return to their normal activities. The fact that the patient has torn the meniscus increases their risk of arthritis over the next 15 to 20 years. Removing the torn fragments does not increase this risk, but merely decreases the symptoms from the tear.
Recovery from an arthroscopy to remove the torn meniscus is relatively short. It is a minimally invasive outpatient surgery with typically 2 to 3 small puncture wounds to perform the surgery. The patient will typically be weight bearing as tolerated, but he/she may need to use crutches for a few days following the surgery. Swelling typically improves during the first week. Patients with sedentary jobs can return within one to two days. More physical laborers may take longer to recover. Patients typically return to sports or exercise by 4 to 6 weeks following a short period of physical therapy.