Open reduction of a lateral femoral notch associated with an acute anterior cruciate ligament tear.

The lateral notch is a radiographic sign that describes a depression in the lateral femoral condyle near the terminal sulcus. The sign was first described in association with chronic instability in an anterior cruciate ligament-deficient knee. Recently, the senior author, after a prospective study, reported that these lateral notches might occur acutely at the time of anterior cruciate ligament injury. We report such a case in which the lateral femoral condylar depression fracture resulted in symptoms of lateral compartment incongruity. Open reduction and internal fixation were required. Anterior cruciate ligament reconstruction was performed as a staged procedure 2 months after fracture reduction. The postoperative result has been excellent for over 5 years. This case is an example that lateral femoral notches may be acute and a source of symptoms. In some cases, reduction and fixation of significant depressions in association with ligament reconstruction can alleviate these symptoms and may improve the patient's long-term result.