Patellar apprehension test is better for ruling in or ruling out patellar dislocation?

• A. Ruling in
• B. Ruling out
• C. Both
• D. Neither

Answer: (A)

A positive patellar apprehension test indicates patellar instability and is most useful for ruling in patellar dislocation. When the patella is displaced laterally and the patient shows apprehension or fear of dislocation, this reaction strongly suggests an underlying tendency for patellar instability, often related to prior dislocation events. Because this response tends to be specific to instability, a positive result strongly supports the diagnosis of patellar dislocation risk.

However, a negative result does not reliably rule out dislocation risk, since instability can be present without eliciting apprehension in some individuals, and other factors like neuromuscular control or chronic laxity may mask a positive test. Therefore, the test is better at confirming (ruling in) patellar dislocation rather than excluding it.