Results of direct exchange or debridement of the infected total knee arthroplasty.

In this literature review, 30 reports provided outcome data on 37 direct exchange arthroplasties, 530 open debridements, and 23 arthroscopic debridements. The average followup was approximately 4 years, but the range was broad (range, 0.02-14 years). Infection was controlled in 33 of the 37 infected total knee arthroplasties (89.2%) treated by direct exchange arthroplasty, in only 173 of the 530 infected total knee arthroplasties (32.6%) treated by open debridement and retention of the prosthetic components, and in 12 of the 23 infected total knee arthroplasties (52.2%) treated by arthroscopic debridement. There was wide variability in associated antibiotic therapy. Factors associated with successful direct exchange included infections by gram-positive organisms, absence of sinus formation, use of antibiotic-impregnated bone cement for the new prosthesis, and 12 weeks of antibiotic therapy. Direct exchange arthroplasty failed in four of 37 knees; two were in patients with rheumatoid arthritis who were taking corticosteroids. Factors associated with successful debridements included those done within 4 months of the index procedure, or in patients with less than 4 weeks of symptoms, antibiotic sensitive gram-positive organisms, well-fixed components with no radiologic evidence of osteitis, and in young healthy patients. Factors associated with the failed debridements included postoperative drainage for more than 2 weeks, sinus tracts present at the time of the debridement, a hinged prosthesis, and an immunocompromised host. Direct exchange can be successful with a sensitive organism in a healthy host with prolonged antibiotic therapy. Debridement can be successful in early infections in a healthy host.