Medial Meniscal Tear
Overview
Plain-Language Overview
A medial meniscal tear is an injury to the cartilage on the inner side of the knee joint, which acts as a cushion and stabilizer. This condition affects the musculoskeletal system, specifically the knee, and can cause pain, swelling, and difficulty moving the knee normally. The meniscus helps absorb shock and distribute weight during activities like walking and running, so a tear can lead to discomfort and limited mobility. People with this injury often experience a sensation of the knee locking or catching. It commonly occurs during sports or activities that involve twisting or sudden changes in direction. Over time, untreated tears may contribute to joint degeneration and arthritis.
Clinical Definition
Medial meniscal tear is a disruption of the fibrocartilaginous structure of the medial meniscus within the knee joint, typically caused by acute trauma involving twisting or valgus stress on a flexed knee or by chronic degenerative changes. The medial meniscus is more frequently injured than the lateral meniscus due to its firm attachment to the tibial plateau and joint capsule. This injury results in mechanical symptoms such as joint line tenderness, locking, and effusion, and can impair knee stability and function. It is clinically significant because it predisposes patients to early osteoarthritis and may require surgical intervention if symptomatic. Diagnosis is often confirmed by magnetic resonance imaging (MRI), which shows the tear pattern and extent. The tear can be classified by location (e.g., posterior horn, body) and pattern (e.g., longitudinal, bucket-handle, complex).