Perioperative denosumab exposure and risk of revision after total hip and knee arthroplasty in osteoarthritis: a registry-based data linkage study.

UNLABELLED: Osteoarthritis patients undergoing THA or TKA were studied to compare the cumulative incidence of revision after perioperative denosumab versus alendronate. Denosumab was not associated with differences in the incidence of revision after THA but was associated with a higher revision incidence after TKA, mainly driven by aseptic tibial loosening.

BACKGROUND

Osteoarthritis is highly prevalent, and the number of total hip (THA) and knee arthroplasties (TKA) continues to rise. This study aimed to evaluate the risk of revision associated with perioperative exposure to denosumab versus alendronate in patients undergoing THA or TKA for osteoarthritis.

METHODS

This retrospective cohort study used data from the Emilia-Romagna Registry of Orthopedic Prosthetic Implants (RIPO). Patients undergoing primary THA or TKA for osteoarthritis between 2011 and 2023 were included. Perioperative exposure was defined as at least one dispensing of denosumab or alendronate within 180 days before or after surgery. The primary outcome was first revision. Revision risk was analysed using cumulative incidence functions, treating death and emigration as competing events, and groups were compared using Gray's test.

RESULTS

The THA cohort comprised 129 denosumab and 922 alendronate users. Revision occurred in 4 denosumab (3.1%) and 21 alendronate patients (2.3%); no significant difference was observed in competing risk analyses (Gray's p = 0.623). In the TKA cohort, 117 denosumab and 940 alendronate users were analysed. Here 8 denosumab patients (6.8%) and 18 alendronate patients (1.9%) required revision, with a significant difference in cumulative incidence (Gray's p = 0.002). Revisions in denosumab users were mainly due to aseptic tibial loosening.

CONCLUSIONS

Perioperative denosumab exposure was associated with a higher cumulative incidence of revision after TKA in this cohort. These findings should be interpreted cautiously and do not imply causality. The observed pattern may reflect complex interactions between antiresorptive therapy and joint-specific biomechanical factors, which warrant further investigation.