The Incidence of Dislocation Utilizing a Neck Sparing Stem in Primary THA in Community Based Practices with the Posterior Approach

Abstract

This study retrospectively reviews the clinical results of a novel proximal neck-sparing cementless prosthesis for primary Total Hip Arthroplasty (THA). This neck-sparing prosthesis preserves the entire circumference of the femoral neck. The porous coated surface is located only within the femoral neck region. This study group included 338 primary THA’s from three institutions. All approaches and techniques were similar, using a postero-lateral approach in all cases. Average follow-up was 38 months (range 12-56 months). There were five stem revisions (1.5%) in this group. Two stems were revised for aseptic loosening, two were revised for recurrent dislocation, and one was revised for a chronic periprosthetic infection employing a two-stage protocol. We had 3 dislocations (0.88%) and all three had re-operations. The neck sparing prosthesis is alluring as it saves almost the entire femoral neck and requires minimal deep posterior soft tissue releases. Our dislocation rate in this series was low. Insertion of a neck sparing prosthesis requires fastidious preparation and gentle insertion, but we find this design to provide reliable clinical function at short-term follow-up.

Keywords

• hip
• arthroplasty
• posterior approach
• dislocation
• neck sparing
• and risk factors
• primary