THA ACA workflow
The axis for surgical success
More accurate acetabular cup positioning techniques will be important for contemporary total hip arthroplasty (THA). The THA ACA (Acetabular Center Axis) workflow is patient-specific, independent of variations in anatomy or pelvic position. It gives the surgeon the orientation of reamer in relation to the ACA center axis and therefore determines precisely the cup position. The cup center should preferably coincide within 4 mm of the acetabular center axis to maximize stability and to minimize impingement that may result in accelerated wear, reduced range of motion, dislocation or unexplained pain.
The system relies on readily accessible anatomic landmarks of the acetabulum (including optionally the transverse acetabular ligament), making it significantly attractive for surgeons who use CT-free planning. Leg length and offset information are achieved by palpating specific points on the leg. THA ACA is especially suitable for less invasive surgical technique and THA performed in lateral patient position.