AN ULTRASONIC-BASED GUIDANCE SYSTEM FOR ACCURATE COMPONENT PLACEMENT IN TOTAL HIP ARTHROPLASTY

Acetabular component positioning is highly correlated with total hip arthroplasty (THA) outcomes. Multiple reports however indicate that less than 50% of acetabular cups are placed within surgeon-desired ranges for abduction and anteversion angles when using conventional cup positioning techniques. Issues with improper placement include instability-dislocation, impingement and impact on range of motion, polyethylene wear, leg length discrepancy, and gait mechanics. Accuracy in placement of the acetabular component is complicated by the need to estimate cup impactor angles to create desired cup position. A low cost approach to THA using Image-based Ultrasonic Guidance (IUG) (Orthosensor, Sunrise, FL) coupled to existing surgical tools is presented. IUG utilises acoustic measurement techniques for achieving optimal component positioning and leg length. A precisely machined Hip Test Fixture (HTF) has been built to simulate the anatomical pelvis, acetabular cup, and femur to validate system accuracy.The IUG w...