401. Predictors of Treatment Failure for Hip and Knee Prosthetic Joint Infections in the Setting of Prosthesis Removal: A Multi-Center Retrospective Cohort

Abstract Background Prosthetic hip and knee joint infections (PJIs) are challenging to eradicate despite prosthesis removal and long courses of antibiotics. We aimed to describe the risk factors for PJI treatment failure in a multicenter retrospective cohort. Methods A retrospective cohort of individuals who underwent prosthetic joint removal for a PJI at one of five hospitals in Toronto, Ontario, Canada from 2010–2014. Individuals eligible for the cohort were obtained by searching operative listings and PJIs were defined according to the criteria of the Musculoskeletal Infection Society. Treatment failure was defined as recurrent PJI, amputation, death or chronic antibiotic suppression. Potential risk factors for treatment failure were abstracted by chart review and assessed using a Cox proportional hazards model. Results 533 PJIs were analyzed over a median follow-up duration of 1102 days with 21 surgeons performing more than 5 revision arthroplasties for a PJI. Two-stage procedures were performed in 81% (430/533) and the most common organism was coagulase negative staphylococci (32%). Treatment failure occurred in 28% (150/533) over 1443 patient-years and was caused by a different bacterial species in 53% (56/105). On multivariate analysis the characteristics associated with PJI treatment failure included liver disease (adjusted hazard ratio (aHR) 3.12, 95% confidence interval (95% CI) 2.09–4.66), the presence of a sinus tract (aHR 1.53, 94% CI (1.12–2.10), preceding debridement with prosthesis retention (aHR 1.68, 95% CI 1.13–2.51), a one-stage procedure (aHR 1.72, 95% CI (1.28–2.32), and infection due to Gram-negative bacilli (aHR 1.35, 95% CI 1.04–1.76). Conclusion PJI treatment failure remains high despite prosthesis removal and the patient risk factors identified are non-modifiable. Novel treatment paradigms are urgently needed along with efforts to reduce orthopedic surgical site infections. Disclosures All authors: No reported disclosures. </jats:sec

Synthetic Graft Compared with Allograft Reconstruction for Extensor Mechanism Disruption in Total Knee Arthroplasty: A Multicenter Cohort Study

© American Academy of Orthopaedic Surgeons. Background:Extensor mechanism disruption after total knee arthroplasty is a serious complication leading to notable patient morbidity. The purpose of this study is to compare the outcomes of extensor mechanism allograft with synthetic graft reconstruction.Methods:We retrospectively identified all patients who underwent extensor mechanism reconstruction using either allograft or synthetic graft from two high-volume academic arthroplasty institutions between 2006 and 2017. We collected extensor lag, need for ambulatory aids, and patient-reported outcome measures, as well as the incidence of postoperative complications and revision surgeries. We evaluated cost differences, considering both material cost and the need for revision surgery.Results:We identified 27 cases. A significantly greater postoperative extensor lag was found in the allograft group (P = 0.05). Graft failure after synthetic reconstruction was zero, with an overall revision surgery rate of 15%. Graft failure was 21%, and the revision surgery rate was 43% after allograft reconstruction. The allograft cost was significantly higher compared with the synthetic graft cost (P = 0.001). The mean total cost was 4,733.08 CAD for the synthetic group and 24,050.40 CAD for the allograft group (P = 0.17).Discussion:Synthetic reconstruction for extensor mechanism disruption shows benefit in postoperative extensor lag, graft failure, revision surgery, and cost when compared with allograft.Level of Evidence:Level III

Predictors of Treatment Failure for Hip and Knee Prosthetic Joint Infections in the Setting of 1- and 2-Stage Exchange Arthroplasty: A Multicenter Retrospective Cohort

AbstractBackgroundProsthetic hip and knee joint infections (PJIs) are challenging to eradicate despite prosthesis removal and antibiotic therapy. There is a need to understand risk factors for PJI treatment failure in the setting of prosthesis removal.MethodsA retrospective cohort of individuals who underwent prosthesis removal for a PJI at 5 hospitals in Toronto, Canada, from 2010 to 2014 was created. Treatment failure was defined as recurrent PJI, amputation, death, or chronic antibiotic suppression. Potential risk factors for treatment failure were abstracted by chart review and assessed using a Cox proportional hazards model.ResultsA total of 533 individuals with prosthesis removal were followed for a median (interquartile range) of 814 (235–1530) days. A 1-stage exchange was performed in 19% (103/533), whereas a 2-stage procedure was completed in 88% (377/430). Treatment failure occurred in 24.8% (132/533) at 2 years; 53% (56/105) of recurrent PJIs were caused by a different bacterial species. At 4 years, treatment failure occurred in 36% of 1-stage and 32% of 2-stage procedures (P = .06). Characteristics associated with treatment failure included liver disease (adjusted hazard ratio [aHR], 3.12; 95% confidence interval [CI], 2.09–4.66), the presence of a sinus tract (aHR, 1.53; 95% CI, 1.12–2.10), preceding debridement with prosthesis retention (aHR, 1.68; 95% CI, 1.13–2.51), a 1-stage procedure (aHR, 1.72; 95% CI, 1.28–2.32), and infection due to Gram-negative bacilli (aHR, 1.35; 95% CI, 1.04–1.76).ConclusionsFailure of PJI therapy is common, and risk factors are not easily modified. Improvements in treatment paradigms are needed, along with efforts to reduce orthopedic surgical site infections.</jats:sec