Risk factors for one-year mortality in 440 femoral peri-implant fractures: insights from the PIPPAS prospective, multicentre, observational study

Abstract

Aims: The Peri-Implant and PeriProsthetic Survival AnalysiS (PIPPAS) study aimed to investigate the risk factors for one-year mortality of femoral peri-implant fractures (FPIFs).

Methods: This prospective, multicentre, observational study involved 440 FPIF patients with a minimum one-year follow-up. Data on demographics, clinical features, fracture characteristics, management, and mortality rates were collected and analyzed using both univariate and multivariate analyses. FPIF patients were elderly (median age 87 years (IQR 81 to 92)), mostly female (82.5%, n = 363), and frail: median clinical frailty scale 6 (IQR 4 to 7), median Pfeiffer 4 (1 to 7), median age-adjusted Charlson Comorbidity Index (CCI) 6 (IQR 5 to 7), and 58.9% (n = 250) were American Society of Anesthesiologists grade III.

Results: Overall, 90.5% (n = 398) of the patients were treated surgically, 57.0% (n = 227) retained the implant, and 88.7% (n = 353) managed with fixation. Mortality rates were 8.2% (n = 3.6) in-hospital, 11.4% (n = 50) at 30 days, 21.1% (n = 93) at six months, and 21.6% (n = 95) at 12 months. Medical complications, mainly delirium, were common in the acute setting (52.7%, n = 215). The nonunion rate was 4.1% (n = 18). Mortality risk factors in the univariate analysis were age, living at a nursing home, no walking outdoors, frailty variables, fractures in the distal epiphysis, fractures around a proximal nail, discharge to a healthcare facility, and no osteoporotic treatment at discharge. Protective factors against mortality in the univariate analysis were surgical treatment by an experienced surgeon, management without an arthroplasty, allowing full weightbearing, mobilization in the first 48 hours postoperatively, and geriatric involvement. Risk factors for mortality in the multivariate analysis were cognitive impairment (Pfeiffer's questionnaire) (hazard ratio (HR) 1.14 (95% CI 1.05 to 1.23), p = 0.002), age-adjusted CCI (HR 1.18 (95% CI 1.07 to 1.30), p = 0.001), and antiaggregant or anticoagulant medication at admission (HR 2.00 (95% CI 1.19 to 3.38), p = 0.009). Haemoglobin level at admission was protective against mortality (HR 0.85 (95% CI 0.74 to 0.97), p = 0.018).

Conclusion: Mortality in FPIFs occurs mainly within the first six months of follow-up. Early co-management and clinical optimization, particularly targeting frail older patients, is crucial in reducing mortality following these fractures.

Fig. 1

Diagram demonstrating the Broggi classification system for femoral peri-implant fractures, excluding type D fractures.

Fig. 2

Kaplan-Meier curves for one-year mortality. a) Global mortality curve (95% CI 9.710 to 10.168). b) Mortality curves for femoral peri-implant fracture (FPIF) around a nail (95% CI 9.053 to 9.999) and FPIF around a plate (95% CI 10.251 to 11.558) mortality curves. c) Mortality curves for management strategies “implant removed” (95% CI 10.133 to 11.164) vs “implant retained” (95% CI 9.326 to 10.410).

Fig. 3

Sankey diagrams (made in Flourish; Canva, Australia) with femoral peri-implant fracture (FPIF) type distribution according to Broggi’s classification. a) Bone segment where the FPIF is located related to FPIF subtypes according to the implant. b) A, B, C, and E types related to FPIF subtypes according to the implant.