What is the lifetime risk of revision for patients undergoing total hip arthroplasty? a 40-year observational study of patients treated with the Charnley cemented total hip arthroplasty.

AIMS: The purpose of this study was to determine the lifetime risk of revision surgery for patients undergoing Charnley cemented total hip arthroplasty (THA), with 40-year follow up, using death as a competing risk.
MATERIALS AND METHODS: We retrospectively reviewed 2000 cemented Charnley THAs, with 51 living hips available at 40 years.
RESULTS: The cumulative risk of revision or removal for any reason was 13% (95% confidence interval (CI) 12 to 15). Patients aged under 50 years at the time of surgery had a 35% (95% CI 28 to 42) risk of revision or removal for any reason (Hazard Ratio (HR) 3.6; 95% CI 2.5 to 5.2; p < 0.001), patients 50 to 59 years old had a 20% risk (95% CI 16 to 24) (HR 2.1; 95% CI 1.5 to 2.8; p < 0.0001), patients aged 60 to 69 years had a 9% risk (95% CI 7 to 11) (reference point), and patients ≥ 70 years old had a 5% risk (95% CI 4 to 7) (HR 0.96; 95% CI 0.6 to 1.5; p = 0.86) during their lifetime. Men had a higher risk of revision or removal for any reason (HR 2.1; 95% CI 1.7 to 2.7; p < 0.001).
CONCLUSION: With almost all the patients in this series followed up till either death or revision, we have been able to develop a 'rule of thumb' for lifetime likelihood of revision or implant removal for the Charnley THA: one in three for patients < 50 years, one in five for patients 50 to 59 years, one in ten for patients 60 to 69 years, and one in 20 for patients ≥ 70 years. The results provide a benchmark for comparison of outcomes, for the newer designs of THA. Cite this article: Bone Joint J 2016;98-B:1436-40. ©2016 The British Editorial Society of Bone & Joint Surgery.