NCB-PP® locking plates outcomes in the treatment of periprosthetic femoral fractures. Analysis of a retrospective cohort of 89 patients.

Introduction: The management of periprosthetic femoral fractures is particularly complex in an elderly, frail population, with an increasing incidence due to the increase in femoral prosthesis surgery. The use of locking plates is now widely recommended. The primary objective of this study was to present the results of NCB-PP® locking plates in the management of periprosthetic femoral fractures. The secondary objective was to determine the influence of weight-bearing time on morbidity and mortality and on walking ability. The hypothesis of this study was that NCB-PP® plates would provide radio-clinical results equivalent to those reported in the literature with no influence of time to re-weighting on complication rate and walking level at 1 year post-operatively.

Materials and methods: 89 patients (mean age 81 ± 11.9 (28-99), with a female predominance 62/89 (69.7%)) underwent 89 periprosthetic femur fractures (74 THA, 11 TKA and 4 interprosthetic) and treated with NCB-PP® plates were retrospectively included between January 2014 and September 2022. Patients were then divided into 2 groups according to the time to postoperative full weight bearing: "immediate" (n = 30) and "delayed" (n = 59) (a minimum of 6 weeks post-operatively).

Results: The mean follow-up time was 14.6 months. At 6 months post-operatively, 91.8% of patients were consolidated. At 1 year, 36.2% had resumed independent walking, 8.7% required one crutch, 13% two crutches, 33.3% walked with a walker and 8.7% were considered non-walkers. There were 12 complications (13.5%), including 7 mechanical (7.9%) and 5 infections (5.6%), with 10 patients (11.2%) requiring a revision surgery. Mortality at 6 months and 1 year was respectively 9 and 12.4%. There was no significant difference between pre- and post-operative walking levels (p = 0.45). There was no influence of the time to reweighting on the level of walking at 1 year (p = 0.874), on complications (p = 0.17) or on mortality at 1 year (p > 0.99).

Conclusion: This study confirms the initial hypothesis and the results of preliminary studies on a smaller sample size regarding bone union of periprosthetic femoral fractures with NCB-PP® plates, with a low rate of mechanical complications. The proportion of patients returning to their previous walking level remains low, but early full weight bearing is still possible without increasing the rate of mechanical complications.

Level of evidence: IV; retrospective cohort study.