Modular intramedullary knee arthrodesis for chronic periprosthetic joint infection after total knee arthroplasty: Patient-reported satisfaction and functional outcomes.

BACKGROUND: Chronic periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is a severe complication causing repeated surgeries and reduced quality of life. When revision is not feasible due to bone loss, extensor mechanism deficiency, or persistent infection, knee arthrodesis (KA) can be a limb-salvage alternative to amputation. This study evaluates functional outcomes, infection control, and patient satisfaction after KA using a cemented modular intramedullary nail (IMN) in chronic PJI after TKA.

METHODS: This retrospective cohort included patients treated with floating KA using a cemented IMN within a two-stage protocol for chronic PJI between 2016 and 2023. Demographic and clinical data, walking ability, use of aids, and residential status were collected. Quality of life was assessed with Short Form-12 (SF-12) physical (PCS) and mental (MCS) scores. Correlation analyses identified factors associated with outcomes.

RESULTS: Fifteen patients were included (mean age 74.4 ± 9.5 years; mean follow up 36 months). No septic recurrence or mechanical failure occurred. Eleven patients (73.3%) were satisfied, and all preferred KA over amputation. Most remained ambulatory with aids and lived independently. Younger age correlated with higher SF-12 PCS (P = 0.02), while more previous surgeries correlated with lower SF-12 MCS (P = 0.046). Taller patients showed lower satisfaction (P = 0.005).

CONCLUSION: Floating KA with a cemented modular IMN is a reliable limb-salvage option for chronic PJI after failed TKA, ensuring infection control, mechanical stability, and acceptable quality of life. Psychological well-being influences satisfaction and should be considered in preoperative counseling to guide preoperative counseling and decisions.