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Total Knee Arthroplasty Periprosthetic Joint Infection With Concomitant Extensor Mechanism Disruption and Soft-Tissue
Bahar Entezari1, Johnathan R Lex2, Madison L Litowski3
1Granovsky Gluskin Division of Orthopaedics, Mount Sinai Hospital, Toronto, Ontario, Canada; School of Medicine, Queen's University, Kingston, Ontario, Canada.
Insights
The "Terrible Triad" complication of periprosthetic joint infection (PJI) after knee replacement leads to poor outcomes. Early amputation or arthrodesis may be considered for these severe cases.
Area of Science:
- Orthopedic Surgery
- Arthroplasty Complications
- Infectious Disease
Background:
- Periprosthetic joint infection (PJI) with extensor mechanism disruption (EMD) and soft-tissue defects, termed the "Terrible Triad," is a severe complication of total knee arthroplasty (TKA).
- This condition presents significant challenges in surgical management and patient outcomes.
Purpose of the Study:
- To define the surgical and clinical outcomes of patients managed for the "Terrible Triad" following TKA.
- To compare outcomes across different combinations of PJI, EMD, and soft-tissue defects.
Main Methods:
- Retrospective review of 188 patients from 2000-2022 undergoing operative management for PJI alone, PJI with soft-tissue defects, PJI with EMD, or the "Terrible Triad."
- A composite outcome measure included infection status, range of motion, extensor lag, and ambulatory status.
- Statistical analyses included ANOVA, Chi-square tests, and Kaplan-Meier survival analysis for mortality.
Main Results:
- The "Terrible Triad" group experienced a 45.5% incidence of above-knee amputation or arthrodesis and an 86.4% unfavorable outcome rate.
- Patients with the "Terrible Triad" had significantly higher odds of an unfavorable outcome (OR=11.6) compared to PJI alone.
- PJI with soft-tissue defects (OR=5.8) and PJI with EMD (OR=3.7) also showed increased odds of unfavorable outcomes.
Conclusions:
- The "Terrible Triad" following TKA is associated with a high rate of poor surgical and clinical outcomes.
- Early consideration of amputation or arthrodesis may be a viable treatment option for patients with this complex condition.
Background:
Periprosthetic infection (PJI) with concomitant extensor mechanism disruption (EMD) and soft-tissue defect-hereinafter termed the "Terrible Triad"-is a devastating complication following total knee arthroplasty. The purpose of this study was to define the surgical and clinical outcomes following management of a cohort of patients who have the Terrible Triad.
Methods:
From 2000 to 2022, 127 patients underwent operative management for PJI alone, 25 for PJI with soft-tissue defects (defined as defects requiring flap reconstruction or being a factor contributing to the decision of performing above-knee amputation or arthrodesis), 14 for PJI with EMD, and 22 for the Terrible Triad. A composite outcome of infection status, range of motion, extensor lag, and ambulatory status at final follow-up was used to compare the proportion of patients in each group with a favorable overall knee outcome. Differences between groups were determined using one-way analyses of variance with post hoc Tukey's tests and Pearson's Chi-square tests or Fisher's exact tests with post hoc Bonferroni adjustments, where applicable. Odds ratios (OR) were calculated for comparison of the overall knee outcome between groups. A Kaplan-Meier survival analysis for patient mortality was performed.
Results:
The mean follow-up was 8.4 years and similar between groups (P = .064). Patients who had the Terrible Triad had a 45.5% incidence of above-knee amputation, or arthrodesis, and an 86.4% incidence of an unfavorable outcome. Compared to patients in the PJI group, patients in the PJI who had a soft-tissue defect (OR = 5.8, 95% CI [confidence interval] 2.2 to 15.7), PJI with EMD (OR = 3.7, 95%CI 1.0 to 12.9), and Terrible Triad groups (OR = 11.6, 95% CI 3.3 to 41.5) showed higher odds of an unfavorable knee outcome.
Conclusions:
This study demonstrates that the total knee arthroplasty Terrible Triad is a dreaded diagnosis with poor outcomes. Clinicians and patients might consider early treatment with amputation or arthrodesis.
Level Of Evidence:
III.
