Injuries to the Posterolateral Aspect of the Knee

Abstract

Seventy-one consecutive patients with posterolateral knee injuries had clinical stability testing abnormalities documented prospectively. We compared these find ings with the incidence and patterns of their injuries documented at surgery. An abnormal reverse pivot shift test was associated with injury to the fibular col lateral ligament (P = 0.01), popliteal components (P = 0.01), and midthird lateral capsular ligament (P = 0.02). An abnormal posterolateral external-rotation test at 30° of flexion was associated with injury to the fibular collateral ligament (P = 0.0001 ) and lateral gastrocne mius tendon (P = 0.01). An abnormal adduction test at 30° of flexion was associated with injury to the poste rior arcuate ligament (P = 0.02). The results of this study should alert the clinician to the possibility of injury to a specific anatomic structure when the correspond ing clinical stability test is abnormal. Because the fib ular collateral ligament was injured in only 23% of the knees in this large series of patients, we recommend that an injury to the fibular collateral ligament not be the sole determining factor in making the diagnosis of pos terolateral injuries. The wide array of injuries to many individual anatomic components that we found indi cates the complexity of injuries to the posterolateral aspect of the knee.