Risk factors for aseptic loosening of Müller-type straight stems
DOI:
https://doi.org/10.3109/17453674.2013.810517Abstract
Background and purpose Even small differences in design variables for the femoral stem may influence the outcome of a hip arthroplasty. We performed a risk factor analysis for aseptic loosening of 4 different versions of cemented Müller-type straight stems with special emphasis on design modifications (2 shapes, MSS or SL, and 2 materials, CoNiCrMo (Co) or Ti-6Al-7Nb (Ti)).Methods We investigated 828 total hip replacements, which were followed prospectively in our in-house register. All stems were operated in the same setup, using Sulfix-6 bone cement and a second-generation cementing technique. Demographic and design-specific risk factors were analyzed using an adjusted Cox regression model.Results The 4 versions showed marked differences in 15-year stem survival with aseptic loosening as the endpoint: 94% (95% CI: 89–99) for MSS Co, 83% (CI: 75–91) for SL Co, 81% (CI: 76–87) for MSS Ti and 63% (CI: 56–71) for SL Ti. Cox regression analysis showed a relative risk (RR) for aseptic loosening of 3 (CI: 2–5) for stems made of Ti and of 2 (CI: 1–2) for the SL design. The RR for aseptic stem loosening increased to 8 (CI: 4–15) when comparing the most and the least successful designs (MSS Co and SL Ti).Interpretation Cemented Müller-type straight stems should be MSS-shaped and made of a material with high flexural strength (e.g. cobalt-chrome). The surface finish should be polished (RaDownloads
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Published
2013-08-01
How to Cite
Clauss, M., Gersbach, S., Butscher, A., & Ilchmann, T. (2013). Risk factors for aseptic loosening of Müller-type straight stems. Acta Orthopaedica, 84(4), 353–359. https://doi.org/10.3109/17453674.2013.810517
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Acta Orthopaedica (Scandinavica) content is available freely online as from volume 1, 1930. The journal owner owns the copyright for all material published until volume 80, 2009. As of June 2009, the journal has however been published fully Open Access, meaning the authors retain copyright to their work. As of June 2009, articles have been published under CC-BY-NC or CC-BY licenses, unless otherwise specified.