Meniscal Tear
Injury to the medial or lateral fibrocartilaginous meniscus, ranging from acute sport-related tears in young patients to degenerative tears in mid-life.
Overview
The menisci distribute load, stabilise the joint, and contribute to lubrication and proprioception. Tears are broadly acute traumatic, typically twisting injuries in young active patients, or degenerative, in which age-related collagen disorganisation predisposes the tissue to failure under physiological loads. The medial meniscus is more commonly torn than the lateral because of its relative immobility.
Epidemiology
Annual incidence is approximately 60 to 70 per 100,000. Traumatic tears peak between ages 20 and 30 with a male predominance; degenerative tears rise sharply after age 50 and are present in nearly a third of asymptomatic adults over 60 on MRI. Concomitant ACL rupture is seen in up to half of acute traumatic tears.
Symptoms
Patients report joint line pain, mechanical symptoms (catching, locking), and effusion. McMurray, Thessaly, and joint line tenderness tests are commonly used; none is individually definitive and clinical diagnosis is strengthened by combining findings with history and imaging.