Titanium and cobalt-chrome cementless femoral stems of identical shape produce equal results.
This study of proximal porous-coated stems of identical shape, but with two types of stem materials (Ti alloy or Co-Cr alloy), was done to determine the differences, if any, in these stems in the following parameters: clinical and functional outcomes; the prevalence of thigh pain; the stem alignment and the stem-canal fill; cup position; the degree of periprosthetic bone loss; the prevalence of polyethylene liner wear and osteolysis; the incidence of aseptic loosening of acetabular and femoral components; and complication rates. In the Ti alloy group, there were 60 patients (70 hips) followed up for a mean of 6.4 years (range, 5-7 years) with a mean age at surgery of 45.3 years and a mean weight of 65.7 kg. In the Co-Cr alloy group, there were 60 patients (70 hips) followed up for a mean of 6.6 years (range, 5-7 years) with a mean age at surgery of 45.4 years and a mean weight of 66.8 kg. Harris hip scores did not differ and the prevalence of transient pain in the thigh was 5% with both stems. No acetabular or femoral component had aseptic loosening in either group. Loss of bone density in the calcar region was more severe in the Co-Cr group. The mean polyethylene linear wear per year was 0.15 mm (SD, 0.015) in the Ti group and 0.14 mm (SD, 0.013) in the Co-Cr group. No acetabular or femoral osteolysis was seen in any patient. The clinical and radiographic results of this study did not show any significant differences between the Ti and Co-Cr alloy femoral components; however, the Ti alloy femoral component retained greater periprosthetic bone as compared with a Co-Cr alloy femoral component.
Kim
Young-Hoo
YH
Joint Replacement Center of Korea, Ewha Womans University College of Medicine, Seoul, Korea. younghookim@netsgo.com
D000328:Adult; D019644:Arthroplasty, Replacement, Hip / Q000379:methods; D002858:Chromium Alloys; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D012189:Retrospective Studies; D014025:Titanium
D002858:Chromium Alloys; D014025:Titanium