Knee arthrofixation with modular nail as salvage for periprosthetic infection: Evaluation of quality of life and implant survival

Abstract

Introduction

Periprosthetic joint infection (PJI) is a complication that can lead to severe bone defects, a lack of soft tissue coverage, and poor infection control. Knee arthrofixation, using modular intramedullary nails and a cement block as a spacer, is a salvage procedure for these situations, serving as an alternative to limb amputation.

The primary objective of this study was to evaluate the postoperative quality of life of patients undergoing knee arthrofixation with modular intramedullary nails. Secondary objectives included assessing implant survival, complication rates, and the rate of infection cure.

Materials and methods

A retrospective cohort study was conducted on 34 patients treated with knee arthrofixation using an intramedullary nail as a definitive treatment for periprosthetic infection between 2015 and 2023 at a single institution. The minimum follow-up period was one year. In addition to the initial evaluation of clinical characteristics, patients' quality of life was assessed using the Oxford Knee Score (OKS). Implant survival, complications, and the proportion of patients who achieved infection cure according to Laffer's criteria were also analyzed.

Results

At the one-year follow-up after surgery, a moderate-to-good quality of life score of 32, standard deviation (SD) 12, was reported, with an implant survival rate of 77%, 95% confidence interval (CI) 56–88%, according to Kaplan–Meier estimates. The number of previous surgeries before arthrofixation was 9. Soft tissue flap coverage was required in 46.4% of cases. A modular intramedullary nail was used as the implant of choice in 88.2% of cases. Except for one case, all patients presented with a severe AORI 3 bone defect. Following reconstruction, the average limb length discrepancy was 28 mm. A 35% complication rate was recorded, including six amputations, three nail replacements due to persistent infection, and three implant fractures. The most frequently identified primary pathogen was methicillin-sensitive Staphylococcus aureus. The infection cure rate in this series was 56.5%.

Conclusion

Knee arthrofixation is a feasible limb-salvage strategy for recurrent periprosthetic infections, though our series showed increased reinfection rates and lower implant survival compared with previous reports.

Evidence level

IV.