Introduction: The revision rates were high for patients with Metasul-LDH® hip prosthesis (LDH = large-diameter head) with DUROM® acetabulum components implanted in a single centre between 2003 and 2008. This suggested that there was a system-related weakness in total hip replacements with large diameter heads. It was suspected that the tapered connection between head and stem was responsible for the implantation failure. This led to a scientific reappraisal of the unsuccessful hip prostheses, in order to clarify whether there was a tribological problem or a cone failure. Method: To this end, data on serum metal concentrations, types of prosthesis and stem alloys were collected and analysed for the 315 patients with 350 DUROM®-LDH-HTP. Results: There were significant differences between blood metal concentrations in patients with different types of stem. For patients with titanium stems, there were more serious affects on bone substance surrounding the affected joint, and significantly higher serum cobalt concentrations. Conclusion: It was concluded that the problem did not lie with the tribology of the sliding surfaces, but with the cone-stem connection.
Georg Thieme Verlag KG Stuttgart · New York.