Peri-periprosthetic femoral fractures: a single-centre case series of a rare and challenging clinical scenario.

Abstract

Purpose: Periprosthetic femoral fractures (PFFs) are an increasingly common complication of hip arthroplasty. A poorly defined scenario is a new femoral fracture after a previously treated PFF has united, which we term a peri-periprosthetic femoral fracture.

Methods: We retrospectively reviewed 154 surgically treated PFF episodes in patients aged over 65 years at our institution between 2011 and 2021. A peri-periprosthetic fracture was defined as a new acute femoral fracture after documented radiographic union of a previously treated PFF. Clinical, surgical, and radiographic data were reviewed.

Results: Seven patients (4.5% of the institutional PFF cohort) met the criteria. Mean age was 83.1 years and 6 (85.7%) were female. The mean interval to the peri-periprosthetic fracture was 37.3 months (median 27; range 7-105). By the Vancouver classification, 3 fractures were type B1, 1 type B3, and 3 type C. Treatment was individualised to fracture configuration, prosthetic stability, hardware, and bone stock. Radiographic union was documented in all 4 patients with adequate follow-up, at a mean of 4.3 months. Five patients regained ambulation; one with pre-existing limitations did not, and ambulatory status was unavailable for one. Medical complications occurred in 2 patients, and no major orthopaedic complication required reoperation. Mortality was 14.3% at one year and 42.9% at two years.

Conclusion: Peri-periprosthetic femoral fractures constitute a rare and technically demanding scenario, distinct from delayed union, nonunion, refracture through an incompletely healed fracture, and fixation failure. Treatment should be individualised to prosthetic stability, pre-existing hardware, fracture morphology, and residual bone stock.