Nonmodular One-Unit Cementless Acetabular Compoment in Primary Total Hip Arthroplasty: With Alumina to Polyethylene Articulation

Abstract

Purpose : Modular acetabular components have the potential of fretting and back side wear leading to osteolysis. The present study evaluated the outcomes of total hip arthroplasties (THAS) using a nonmodular cementless acetabular component with those of press-fit titanium mesh coatings fixed. Materials and Methods : Eighty-two primary THAS in 75 patients were performed consecutively between April 1995 and August 1998. Sixtytwo hips were eligible for follow up for an average 62 months. Mean patients age was 59 years. The clinical evaluation was performed using the modified Harris hip score (HHS), inguinal pain and limping. The radiologic evaluation included, component stability, polyethylene wear rate, pelvic osteolysis and the remodeling pattern around the acetabular component. Results : Mean HHS improved from 50.2 points preoperatively to 90.5 points at the most recent follow up. All components were stable radiologically. The linear polyethylene wear rate was 0.07 mm/year. No pelvic osteolysis was found. Polar gaps found in 25 hips (40%) in postoperative radiographs and disappeared during follow up in 22 hips (88%). One hip was revised due to chronic unreduced dislocation. Conclusion : Total hip arthroplasty with a nonmodular cementless acetabular component seems to enhance satisfactory early mid-term results in terms of stability and acetabular remodeling with minimal wear and pelvic osteolysis.