Long-Term Survival and Results at a Mean Follow-Up Period of 24 Years of a Tapered Straight, Collarless, Grit-Blasted, Titanium Alloy Stem

Abstract

BackgroundThere is limited evidence on the survivorship of patients who undergo cementless stem implantation, beyond 20 years of the hip arthroplasty. We report implant survival and results of the CLS Spotorno femoral stem until 30 years from implantation. MethodsSurvival analysis of 147 CLS Spotorno stems in 119 patients for an average period of 24 years (20-30) from the date of implantation was performed. During the course of the follow-up period, 33 patients (39 hips) died. The information on the survival of their hip implant at the time of death was gathered from their relatives and general practitioners. Sixty-six patients (86 hips) undertook the complete survey along with radiographic examination, while 18 subjects (20 hips) were interviewed over the telephone. The factors influencing survival, functional outcomes, and level of satisfaction with surgery were evaluated. ResultsThe overall estimated survival of the stems was 89.9% after 30 years (95% confidence interval [CI] 83.5-93.9). Survival with femoral revision for aseptic loosening as an end point was 93.1% (95% CI 87.1-96.4). In the worst-case scenario, an overall implant survival of 77.2% (95 CI% 80.3-82.7) was observed after 24 years. Patients who were older than 50 in age at the time of surgery had better survival rates (P = .026). The mean Harris Hip Score at follow-up was 83.1 (range 43-100) and the level of satisfaction was 9/10. The main determinant of postsurgical satisfaction was Harris Hip Score, whereas radiographic alterations explained little with respect to the variation in the outcomes. ConclusionThe cementless CLS Spotorno stem displayed satisfactory results 24 years after implantation and high estimated survival until 30 years from surgery. However, patients below the age of 50 at the time of surgery have an increased risk of undergoing revision of their femoral stem.