A computerized system for radiographical evaluation in total hip arthroplasty

In the field of orthopaedic surgery radiographical image evaluation is frequently used to determine possible pathological processes. For total hip arthroplasty in particular, it is important to evaluate both preoperative femoral morphology and post-operative prosthesis performance in terms of bone adhesion to the implant and, consequently, loosening or stability of prosthesis components. References to a method called Roentgen stereophotogrammetric analysis (RSA) exist in the literature; however, the authors note that this method is expensive and requires the insertion of markers during the operation. Here we present an alternative computerized method for radiographical evaluation which we call radiographical evaluation system in total hip arthroplasty (RESTHA). The accuracy and the repeatability of the method have been evaluated using a medium-sized pelvis-femur system made of composite material. A mean error of +/- 2 mm has been associated to each experimental point. A post-operative inquiry case study is presented to indicate the applicability of the method.