Increased risk of early failure of multiply revised total hip arthroplasty.

AIMS: As the demand for revision total hip arthroplasty (rTHA) grows, understanding how successive revision procedures influence implant survivorship and patient outcomes becomes increasingly important. This study aimed to evaluate the association between revision number and implant survivorship following aseptic rTHA.

METHODS: We analyzed 845 aseptic rTHAs performed between January 2003 and December 2023. Index primary THA dates, rTHA sequence, and reoperations were sourced and verified using hospital records, national registry data, and radiological records. Cases were stratified by revision number: first (R1), second (R2), or third and beyond (R3+). Re-revision risk was evaluated using cumulative incidence functions and Fine-Gray competing-risk regression, with death treated as a competing event.

RESULTS: Of 845 rTHAs (717 patients), 838 (710 patients) with confirmed index THA were included: 598 R1, 155 R2, and 85 R3+. At two years, cumulative incidence of re-revision was 10.2% (95% CI 8.0 to 12.9) for R1, 14.2% (95% CI 9.6 to 20.8) for R2, and 17.7% (95% CI 11.0 to 27.7) for R3+. Unadjusted competing-risk regression demonstrated a higher cumulative incidence of re-revision in R2s compared with R1s. However, after multivariable adjustment, revision number was not independently associated with a statistically significant increase in re-revision risk. Across all revision groups, the highest risk of failure occurred within the first two postoperative years, particularly following rTHA for instability.

CONCLUSION: Re-revision following aseptic rTHA occurs most frequently within the first two postoperative years, with instability representing the dominant mode of early failure. Although multiply revised hips demonstrate poorer survivorship in unadjusted analyses, competing-risk models substantiated that rTHA number alone was not independently associated with a significantly increased risk of re-revision. These findings emphasize the importance of early risk mitigation strategies and informed patient counselling in the setting of repeated rTHA.