Snapshot A 65-year-old woman presents with intermittent knee pain and locking for the past few months. Her symptoms are worse when climbing stairs or when squatting. She denies any inciting trauma or event and denies participation in any rigorous sports. She has no other significant past medical history. On physical exam, there is a mild effusion with a positive McMurray test. Posterior and anterior drawer tests are negative. Introduction Clinical definition a knee injury caused by meniscal tears, categorized into two types acute meniscus tear age-related degeneration of meniscus part of the "terrible triad" anterior cruciate ligament tear medial collateral ligament tear medial meniscus tear Epidemiology demographics male > female < 40 years of age are more likely to have acute tears > 40 years of age are more likely to have degenerative tears lateral meniscus tears are most common location menisci are located between the femoral condyles and tibial plateau risk factors acute tears login to view 1 more bullet degenerative tears login to view 3 more bullets obesity Pathogenesis two most common mechanisms non-contact trauma from twisting of the knee or sudden acceleration and directional change, often in the context of sports contact injury with varus or valgus forces on the knee repetitive normal forces from age-related degeneration login to view 1 more bullet Associated conditions >30% associated with anterior cruciate ligament injury Presentation Symptoms persistent joint pain after inciting event (acute tears) insidious onset of knee pain (degenerative tears) locking, popping, or catching of the knee during ambulation pain during ambulation, especially with climbing stairs a sensation of joint giving way Physical exam knee effusion and swelling that worsens with activity more common with acute injuries knee pain that worsens with motion, especially with deep knee flexion an impaired range of motion focal joint tenderness normal patellar tracking positive McMurray test for medial meniscus tear login to view 3 more bullets for lateral meniscus tear login to view 3 more bullets Imaging Radiograph indication to rule out other bony pathologies findings typically normal may show secondary findings such as joint effusion Magnetic resonance imaging indications to confirm a meniscus tear when the diagnosis is unclear findings hyperintense signal inside the meniscus Studies Making the diagnosis most cases are clinically diagnosed Differential Anterior or posterior cruciate ligament injury distinguishing factor positive drawer sign Osteoarthritis of the knee distinguishing factor no diffusion present joint stiffness is typically present Treatment Management approach meniscal tears can be managed conservatively or with surgery and depends on various patient factors, including the patient’s age, the presence of comorbidities, and extent of tear Conservative conservative treatment indications login to view 3 more bullets modalities login to view 4 more bullets Medical nonsteroidal anti-inflammatory drugs indications login to view 1 more bullet Operative arthroscopic repair indications login to view 2 more bullets surgeries login to view 2 more bullets Complications Fibrosis Septic arthritis