Risk factors for periprosthetic fractures of the hip: a survivorship analysis.

UNLABELLED: Periprosthetic fracture is an uncommon but typically complex complication of cemented THA usually treated operatively. It is a source of reduced function, subsequent morbidity, and increased mortality. Previous studies may have underestimated the incidence of fracture through loss to followup or failure to use survivorship methodologies. The primary aim of this study was to use survivorship methodology to investigate the incidence of, and risk factors for fracture following primary arthroplasty. We examined a cohort of 6458 primary cemented femoral prostheses implanted during a 17-year period. One hundred twenty-four patients sustained fractures at the tip or below the femoral prosthesis. The incidence of fracture was 0.8% at 5 years and 3.5% at 10 years after primary implant. Patients older than 70 years had a 2.9 times greater risk of sustaining a subsequent fracture. There was no association between fracture and gender or implant type. These rates are higher than those reported for cemented arthroplasties. Older patients should be counseled regarding their higher risk of periprosthetic fracture, and additional research is required to elucidate the biologic mechanisms involved. LEVEL OF EVIDENCE: Level II, retrospective prognostic study.