Knee fusion versus above knee amputation as two options to deal with knee periprosthetic joint infection

Periprosthetic joint infection (PJI) poses a significant challenge in total knee arthroplasty (TKA), with recurrence rates as high as 14-28%, leading to substantial morbidity and treatment costs. When conventional treatments fail, knee fusion and above-the-knee amputation (AKA) emerge as alternative options. Existing literature offers conflicting views on the efficacy and impact of knee fusion versus AKA with varied outcomes and limitations.

This retrospective national study spanning 2010-2022 investigates Knee Fusion and AKA as options for addressing Knee PJI. Utilizing PearlDiver Patient Records Database, procedural, and reimbursement data on over 100 million individuals from all the US was evaluated. Readmission rates, costs, and complications of the mentioned procedures were assessed using ICD-9 and ICD-10 codes within a 90-day period and one-year post-operation. Statistical analyses, including chi-square tests and regression models, were conducted using integrated R software.

The study reveals a substantial escalation (p < 0.0001) in the proportion of patients opting for AKA compared to arthrodesis. While age as a demographic factor showed no significant difference, arthrodesis patients exhibited lower comorbidity scores (3.6 ± 2.9 vs. 4.6 ± 3.4, p < 0.001). Arthrodesis correlated with higher 90-day thromboembolism rates (9.2% vs. 7.3%, p < 0.001), blood transfusion requirements (23.2% vs. 14.4%, p < 0.001), and acute renal failure incidence (p = 0.008) but demonstrated lower rates of urinary tract infections (p = 0.047) and cerebrovascular accidents (p < 0.001). At 1 year, arthrodesis was associated with higher infection rates (38.7% vs. 36.4%, p < 0.001). Arthrodesis patients had significant increased 90-day and 1-year readmission rates and hospitalization costs ($12,732 vs. $18,826, p < 0.001).

We found higher rates of 1-year thromboembolism, infection, acute renal failure, and readmission in the arthrodesis group. AKA patients had more sepsis and cerebrovascular accidents. A patient-centered conversation is best for persistent infections and failed revision TKA. Considering the patient's quality of life, goals, and health status, this discussion should cover each procedure's risks and complications.