The meniscus is a structure within the knee that cushions and protects the cartilage or chondral surface. Menisci within the medial and lateral compartments of the knee distribute force evenly throughout the knee. Injury to the meniscus can accelerate the arthritic process over time. Tears may result from trauma to the knee as one is twisting or cutting. In older patients tears often occur with ordinary activities. Occasionally, tears may occur simultaneously with injury to the anterior cruciate ligament (ACL). When the ACL is injured, these tears can result in pain, swelling, and often clicking or catching within the knee.
Physical examination and magnetic resonance imaging (MRI) are useful in confirming tearing of the meniscal cartilage. While conservative treatment can be attempted in this situation, surgical management is often necessary. Depending on the age of the patient, as well as the type of tear, partial menisectomy (removal) or repair of the meniscus is often indicated. These procedures are typically performed arthroscopically as outpatient surgical procedures with good results. Rehabilitation after these procedures is usually minimal, with a return to activity within four to six weeks after partial menisectomy. In cases where the menisci have been removed yet the patient continues to have pain, meniscal replacement or transplantation can offer a reliable alternative.
The chondral surface, or cartilage of the knee, lines the adjacent bones to allow motion across the knee with very little friction. It provides an excellent surface for long-term function across the knee. Osteoarthritis occurs when the chondral surface is globally worn down throughout the knee. At times, however, traumatic injuries of the knee can result in a small focal area of injury to the chondral surface called an osteochondral defect. In these situations, the patient may present with pain, swelling, and catching within the knee. Physical exam and MRI are useful in diagnosing these conditions. New technologies make it possible to resurface the injured area with cartilage for these smaller, more focal lesions. When injury is more globally involved within the knee, osteotomy or joint replacement are often successful treatment options. Patients can obtain more information on the techniques available at the time of their visit.