Impact of stem taper damage on the fracture strength of ceramic heads with adapter sleeves. (March 2019)

• Record Type: Journal Article
• Authors: Dickinson, Emilie C.; Sellenschloh, Kay; Morlock, Michael M.
• Is Part Of: Clinical biomechanics. Volume 63(2019)
• Page Start: 193
• Page End: 200
• Publication Date: 2019-03
• Subjects: Ceramic head -- Adapter sleeve -- Fracture strength -- Revision -- Total hip replacement -- Stem taper damage; Biomechanics -- Periodicals; Osteopathic medicine -- Periodicals; Biomechanics -- Periodicals; Osteopathic Medicine -- Periodicals; 612.76
• DOI: 10.1016/j.clinbiomech.2019.03.005
• Languages: English
• ISSNs: 0268-0033

Abstract

Abstract: Background: Using a new ceramic head with a titanium adapter sleeve offers the possibility of maintaining a well fixed stem when conducting cup revision of a total hip arthroplasty. The aim of this study is to test the impact of stem taper damage on the fracture strength of sleeved ceramic heads. Methods: Pristine zirconia-toughened alumina heads with titanium adapter sleeves (BIOLOX®OPTION System) were tested on damaged Ti-4Al-6V stem tapers in accordance with ISO7206-10. Four distinctive damage types classified as intolerable by the manufacture were investigated, representing various reductions in contact area between the stem taper and sleeve taper as well as damage incurred from previous ceramic head fracture. Findings: The largest reduction in fracture strength occurred for a loss of contact for the entire length of the stem taper. Nonetheless, the fracture strength in all investigated cases was several times higher than that defined by the FDA standards. Interpretation: The use of a titanium sleeve recreates a uniform contact situation between the ceramic head and the outer sleeve taper in situations of damaged stem tapers. For the investigated damage types a high fracture strength of the ceramic head was maintained. This study supports the clinical use for sleeved ceramic heads in instances of greater damages of stem tapers than previously defined in order to spare patients from stem removal. Highlights: Ceramic head fracture strength with titanium sleeve exceeds the requested limit. Taper damage along the length of the taper reduces fracture strength significantly. The definitions of critical taper damage in current guidelines need to be modified.