Re‑fracture risk following implant removal in consolidated hip fractures: a multicenter retrospective cohort study of 575 patients.

PURPOSE: The risk of re-fracture after implant removal in healed hip fractures remains a clinical concern. This study aimed to determine the incidence of re-fracture following implant removal after osteosynthesis of a hip fracture.

METHODS

We conducted a retrospective multicenter cohort study including patients aged ≥ 50 years who underwent implant removal between 2003 and 2023 after radiologically confirmed consolidation of a hip fracture. Patients were identified using procedural codes. Baseline variables included age, sex, ASA classification, fracture type (femoral neck or trochanteric), and implant type (pins/screws, sliding hip device [SHD], or short/long cephalomedullary nail [CMN]). Patients were followed from implant removal until re-fracture, conversion to arthroplasty, death, or end of follow-up, with a minimum follow-up of 1 year. Cox proportional hazards regression was used to assess associations between implant type and re-fracture risk, adjusting for age and sex. Because the proportional hazards assumption was violated, a time-stratified Cox regression and restricted mean survival time analyses were applied.

RESULTS

A total of 575 patients (median age 73 years, IQR 65-81) were included, with a median follow-up of 53 months (IQR 18-100). Lateral hip pain was the most common indication for implant removal (72.5%). The overall re-fracture incidence was 10.4%. Risk varied by implant type: 7.1% after pins/screws, 10.5% after SHD, 18.3% after short CMN, and 15.8% after long CMN removal. Median time to re-fracture was 1.5 months, and 52% occurred after minimal or no trauma. Most re-fractures (85%) occurred within 90 months. Removal of CMNs was associated with a higher re-fracture risk compared with pins/screws (HR 2.79; 95% CI 1.52-5.13), whereas SHD removal was not.

CONCLUSION

Implant removal after consolidated hip fractures carries a measurable risk of re-fracture, most pronounced after CMN removal. These findings highlight the importance of careful patient selection and could aid in decision-making when considering implant exchange or removal following osteosynthesis.

LEVELS OF EVIDENCE: IV, retrospective observational cohort study.