English

Abstract

BACKGROUND: Pivot shift test has been in use as one of the diagnostic test for anterior cruciate ligament injuries over the years. Change in position of the leg was found to produce variation in appreciation of the test. In our observation we found doing the test with leg in external rotation produces better appreciation of the test. AIM: Comparison of external and internal rotation of leg in pivot shift test and quantitating it using image analysis in chronic anterior cruciate ligament injuries. METHODS: Thirty patients with complaints of pain and instability in the knee joint for 2 or more months following injury and having positive Lachman test were chosen randomly. The pivot shift test was performed in all 30 patients first with leg in external rotation and then in internal rotation under anesthesia. Movement of three bony points in relation to each other were captured using 12 mega pixel digital camera and evaluated using image analysis software. RESULTS AND DISCUSSION: The femoral Antero posterior (AP) translation from the Gerdy's point suddenly decreased by 6.5+ 1.8 mm (maximum 13mm, minimum 3mm) in all 30 patients on whom pivot shift was performed in external rotation, whereas the femoral AP translation decreased by 2.9+ 1.17 mm (maximum 5mm, minimum 1mm) in 29 patients when the pivot shift test was done in internal rotation. Arthroscopic findings correlated well with pivot shift test being done in external rotation than in internal rotation. CONCLUSION: The results of this study shows higher diagnostic value of pivot shift test for chronic anterior cruciate ligament (ACL) insufficiency when it is done with leg in external rotation.