MID-TERM RESULTS OF TRISPIKED REFLECTION CEMENTLESS ACETABULAR COMPONENT FOR PRIMARY THR.

Abstract

Summary Sentence: Cementless solid tri-spiked titanium shells, with a polished inner surface and improved locking mechanism, demonstrated excellent fixation and survivorship at mid-term (minimum 5 years) follow-up.

Introduction: The tri-spiked Reflection cup (Smith & Nephew, Memphis) is a second-generation solid titanium shell with a polished inner surface, no screw holes and an improved locking mechanism. The purpose of this prospective study was to evaluate the minimum 5-year clinical & radiographic results and survivorship of this second-generation acetabular component.

Methods: Between 1997 and 2003, 659 primary THA were performed using the Reflection tri-spiked socket. None of the shells had adjuvant fixation with screws. The mean follow-up time was 7.0 years (5 to 11 yrs). The patients were followed prospectively using validated clinical outcome scores (WOMAC, SF-12, Harris Hip scores) and yearly radiographs.

Results: Twenty-seven patients had died before the minimum 5-year follow-up period. The mean Harris Hip and WOMAC scores were 89 and 79 respectively at last follow-up. Three sockets (0.6%) had been revised: two for infection, one for component malpositioning. No cup was revised for aseptic loosening. Six liners were exchanged: three for residual instability, 3 for wear associated with aseptic loosening of the stem. Radiographic review of remaining cups in-situ identified no cases of loosening and only a small number of cups (< 3%) with any osteolysis. The KM survivorship analysis with revision for any reason, was 97.5% and 97.4% at 5 and 10 years, while survivorship of the acetabular component was 99.8% at 5 and 10 years.

Conclusions: This second-generation cementless solid tri-spiked titanium shell, with a polished inner surface and improved locking mechanism, demonstrated excellent fixation and survivorship at mid-term follow-up.