Cemented titanium stems show high migration: transprosthetic drainage system has no advantage over third-generation cementation technique
A newly developed cemented titanium stem with excellent laboratory results using a transprosthetic drainage system (TDS) was clinically tried for the first time. Prognostic radiographic methods including migration measurement and clinical investigation were performed for up to 7 years. Twenty-two patients prospectively and consecutively received total hip replacement using a cemented titanium stem and a threaded Zweymüller cup. Ten stems (CPS) were cemented conventionally with a third-generation cementation technique. In 12 stems (TRIOS) a TDS was used to enhance cement mantle quality. Design of cup and stem was similar in all cases. More than 50% of all stems showed considerable subsidence (>1 mm at 2 years and >2.5 mm at 5 years) and progressive radiolucent lines ( >1 mm at 2 years). Two patients of the TRIOS group had to be revised at 7 years postoperatively. No significant differences were found in radiological parameters (migration, stem subsidence, tilting, occurrence of radiolucent lines) and clinical outcome between the two cementation techniques. All parameters indicate an unfavourable long-term survival. Use of a TDS did not show any significant advantages over the conventional cementation technique. It can be concluded that cementing titanium stems of this design cannot be recommended.