Wilson's Test is a physical examination maneuver used to detect Osteochondritis dissecans (OCD) of the knee, specifically lesions on the lateral aspect of the medial femoral condyle. It's a simple test, but its diagnostic accuracy is limited and should be used in conjunction with other diagnostic methods.
How to Perform Wilson's Test
The test is performed by:
- Having the patient sit with their legs dangling.
- Passively bending the patient's knee.
- Applying a valgus stress (pressure pushing the knee inward).
- Then, internally rotating the tibia (lower leg bone).
- Pain during these movements suggests a possible OCD lesion.
A positive Wilson's Test indicates potential pain and suggests the presence of an Osteochondritis dissecans lesion in the specified area of the knee. However, a negative result doesn't rule out OCD, as lesions in other locations won't be detected by this test.
Important Considerations
- Specificity: The Wilson test is highly specific to lesions in the lateral aspect of the medial femoral condyle. Lesions elsewhere in the knee may not elicit a positive response.
- Sensitivity: The test's sensitivity can vary, meaning it may not always detect lesions that are present.
- Additional Diagnostics: Wilson's test should be considered one component of a larger diagnostic process, not the sole determiner of OCD. Other imaging tests like X-rays and MRIs are crucial for confirming a diagnosis.
This contrasts with Wilson's disease, a genetic disorder involving copper metabolism, diagnosed through blood tests, urine tests, genetic testing, or liver biopsy, not a physical exam maneuver. The ambiguity in the original question necessitates clarifying that this answer focuses on the knee test, not the genetic disorder.
