Radiographic manifestation of hip dislocation after total hip arthroplasty.

OBJECTIVE The authors hypothesized that a patient who has posterior hip dislocation after total hip replacement does not have the same clinical manifestations of malposition as with a natural hip. The present study aimed to study clinical manifestation of hip dislocation after total hip arthroplasty. MATERIAL AND METHOD Thirty-five cases of posterior dislocation after total hip replacement were retrospectively studied by medical records and radiographic evaluation. The study included leg position after hip dislocation, leg length, and leg abduction/adduction angles. RESULTS External rotation of the patient's leg was found in 13 cases (37.1%), neutral position in six cases (17.2%), and internal rotation in 16 cases (45.7%). Measurements of the femoral shaft-vertical axis angle found adduction in 17 cases (average 17.4 degrees, range 1-25 degrees), abduction in 15 cases (average 6 degrees, range 1-15 degrees), and 0 degrees in three cases. Average leg shortening was 3.55 cm (range 0.6-13.5 cm). CONCLUSION The present study shows that patients with hip dislocation after hip replacement can manifest many signs of limb deformity in rotation (internal, external, and neutral) and abduction/adduction positions.