COMPARISON OF 3D PLANNING-ASSISTED AND CONVENTIONAL CUP POSITIONING IN THA

IntroductionMalpositioning of the acetabular cup during total hip arthroplasty increases the risk of dislocation, edge loading, squeaking and can be responsible for early wear and loosening. We hypothesized that the use of three-dimensional visualization tools showing during surgery the planned cup position relatively to the acetabular edge would increase the accuracy of cup orientation. The purpose of this study was to compare 3D planning-assisted with freehand insertion of the acetabular cup.MethodsA randomized, controlled, prospective study of two groups of twenty eight patients each was performed. In the first group, cup positioning was guided by 3D views of the cup within the acetabulum based on a three-dimensional preoperative planning (Figure 1). In the control group, the cup was placed freehand. All of the patients were operated on by the same surgeon through a direct anterior approach in supine position. Cup anteversion and abduction angles were measured on three-dimensional computed tomography r...