What is a positive finding during the posterolateral rotary instability test?

A positive finding during the posterolateral rotary instability test is indicated by subluxation during extension. This test is designed to assess the stability of the knee, particularly the posterolateral corner, which includes structures such as the lateral collateral ligament (LCL) and the popliteus tendon.

When the knee is extended, a sensation of subluxation or instability suggests that these stabilizing structures are compromised, which can significantly affect the function of the knee joint and lead to further injuries. This instability is often a crucial indicator used by athletic trainers and healthcare professionals to diagnose specific knee injuries.

Other possible findings, such as a clicking sound, swelling in the joint, or pain during flexion may be associated with various knee pathologies but do not specifically indicate the instability that the test aims to evaluate. Therefore, subluxation during extension is a clear and definitive positive finding related to the integrity of the knee's stabilizing structures.