The Knee: Breaking the MR Reflex

Abstract

The knee is a large joint prone to trauma and arthritis. Although magnetic resonance (MR) imaging has revolutionized evaluation of knee structures and their abnormalities, imaging the knee makes use of all imaging modalities. Radiography remains important in the diagnosis of knee pathology. This section is dedicated to the initial radiographic evaluation and the sometimes subtle clues to underlying pathology. Knowledge of injury patterns and frequently missed findings will improve the radiologist’s ability to suggest the diagnosis on radiographs. Anatomy A routine radiographic evaluation of the knee includes an anteroposterior view, a lateral view, and a “sunrise” view. In the evaluation of osteoarthritis, weight-bearing views are usually obtained. The bones of the knee joint include the patella, femoral condyles, tibia, and fibula. The knee is composed of the medial tibiofemoral, lateral tibiofemoral, and patellofemoral joints. On AP view, the patella is centrally located between the femoral condyles. There is a slight overlappingoftheproximalfibularheadandlateraltibialplateau. The quadriceps and patellar tendons are seen best on lateral radiograph. The patellofemoral joint is best seen on “sunrise” and lateral views. Table 1 summarizes the important landmarks to evaluate on every radiographic examination of the knee.