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Clinical Pearls

Clinical Utility of Wilson Test for Osteochondral Lesions at the Knee

Zaremski, Jason L. MD, CAQSM; Herman, Daniel C. MD, PhD, CAQSM; Vincent, Kevin R. MD, PhD, CAQSM, FACSM

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doi: 10.1249/JSR.0000000000000203
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Osteochondritis dissecans is a term used to describe the separation of an articular cartilage subchondral bone segment from the remaining articular surface (3). Approximately 80% of lesions in the knee are located at the lateral aspect of the medial femoral condyle (2). The Wilson test can assist with clinical assessment. While the diagnostic utility of this test is limited, a positive test can be used to monitor clinical progression (1). The knee is flexed to 90° with an internally rotated tibia, and the knee is then slowly extended under resistance. This positioning causes the tibial eminence to impinge on the lateral aspect of the medial femoral condyle. A positive test results in pain, typically at approximately 30° of flexion; the pain is then relieved with external rotation of the tibia, thus relieving the impingement. Because of this impingement mechanism, the Wilson test is specifically for lesions at the lateral aspect of the medial femoral condyle and will yield negative results for lesions at other locations.

Figure 1
Figure 1:
Illustrates the start of the test with the leg internally rotated and the knee flexed at 90 degrees.
Figure 2
Figure 2:
Demonstrates changing the leg to external rotation at 30 degrees of knee flexion.


1. Conrad JM, Stanitski CL. Osteochondritis dissecans: Wilson’s sign revisited. Am. J. Sports Med. 2003; 31: 777–8.
2. Lindén B. The incidence of osteochondritis dissecans in the condyles of the femur. Acta Orthop. Scand. 1976; 47: 664–7.
3. Robertson W, Kelly BT, Green DW. Osteochondritis dissecans of the knee in children. Curr. Opin. Pediatr. 2003; 15: 38–44.
Copyright © 2015 by the American College of Sports Medicine.