Predictors for outcome of exchange arthroplasty for periprosthetic joint infections after primary total knee arthroplasty

Abstract

Objective To evaluate the overall failure rate of one or two-stage exchange arthroplasty for infections in total knee arthroplasty (TKA) and the predictors affecting the outcome of exchange. Methods Thirty-nine cases received one or two-stage exchange arthroplasty for periprosthetic joint infections after primary TKA in Shanghai Sixth People′s Hospital affiliated to Shanghai Jiao Tong University School of Medicine and Southeast Hospital affiliated to Xiamen University from January 2012 to November 2014 were reviewed. Periprosthetic tissue and articular fluid of all patients were analyzed by bacterial culture. All patients were followed up for more than one year. C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT) and blood routine were tested every four weeks, and the evaluation on pain, total periprosthetic function, range of motion and deformation of arthroplasty were conducted. Differences between groups were analyzed using chi-square test or Student′s t test when appropriate. A stepwise selection approach in logistic regression analysis was used to screen key predictors for outcome of one or two-stage exchange for infections in TKA. Results There were 39 patients who had undergone one or two-stage exchange for infections in TKA, including 20 males (51.3%) and 19 females (48.7%) with an average age of (62.4±11.7) years. Among the 39 patients, 18 gram-positive strains were isolated from specimens, and 6 gram negative strains, 2 Mycobacterium tuberculosis and 1 candida albicans. Ten of 39 reimplantations developed reinfection. Between the success and failure groups, there were significant differences in the time from primary TKA to revision (P=0.023), operative time (P=0.029), multidrug resistant organisms (P=0.045), the preoperative and post-operative ESR (P=0.002 and P<0.001, respectively) and post-operative CRP (P=0.018). Multivariable logistic regression analysis demonstrated that time from primary TKA to revision (OR=0.96, 95%CI: 0.92-1.00, P=0.025), preoperative ESR (OR= 0.97, 95%CI: 0.95-1.00, P=0.045) and post-operative ESR (OR=0.94, 95%CI: 0.91-0.98, P=0.002) were independent indicators associated with the outcome of one or two-stage revision. Conclusions The failure rate after revision for infected TKA is relatively high. The time from primary TKA to revision, preoperative and post-operative ESR could predict the outcome of one or two-stage revision effectively. Key words: Knee arthroplasty, infection; Arthroplasty, replacement, knee; One-stage revision; Two-stage revision