Grit-blasted titanium femoral stem in cementless primary total hip arthroplasty - A 5-to 10-year multicenter study

A total of 133 cementless primary total hip arthroplasties using the Zweymu ller-Alloclassic grit-blasted titanium tapered stem were performed in 3 ins titutions. The patient cohort was divided into 2 subgroups. nonselected and selected, on the basis of excellent hone stock and age (<65 years old at s urgery). Acetabular components were all cementless, and bearing surfaces we re all alumina-ceramic on polyethylene, After a 7.3-year average follow-up period (range. 5-10 years), 118 primary femoral replacements in 109 patient s could be reviewed fully. Mean age at surgery was 55.7 years (range, 27-84 years). According to the Merle d'Aubigne and Charnley rating system, clini cal results were graded excellent and good in 89% of hips and fair in 11%. Radiologically, early subsidence >2 mm could be detected in 4 hips (3.4%). Calcar atrophy and spot welds were noted in 77% and 82% of hips. Femoral os teolysis granuloma was noted in 4 hips (3.4%). There has been no stem fract ure and no ceramic head breakage. The survivorship at 10 years with definit e femoral aseptic loosening (radiographic failure) as the endpoint was 100% (95% Wilson confidence interval, 78.4%-100%; worst scenario, 95.4%). A sig nificant difference between the nonselected and selected patient subgroups was observed only for early reoperation (P = .03) and proximal stress shiel ding (P = .01). Press-fitting but not filling the femoral canal with a roug h titanium, straight, tapered femoral component represents, at intermediate follow-up, a promising cementless option in primary total hip arthroplasty .