Persistent wound drainage after primary total knee arthroplasty.

A retrospective review of 597 total knee arthroplasties (TKAs) (546 primary and 51 revision cases) was undertaken to define the role and management of persistent postoperative wound drainage and its relationship to possible subsequent joint sepsis. Eight patients with persistent postoperative wound drainage were identified. The follow-up period averaged 4.3 years. These eight patients represent a 1.3% overall incidence of persistent drainage and only 0.5% with the "parent" group of primary TKAs. These very low incidences of wound drainage contrast markedly with the reported 17-50% incidence in the history of those patients who presented for treatment of established knee arthroplasty infections. Such high frequencies observed by the authors and published elsewhere suggested an important relationship between established knee arthroplasty infection and a history of previous prolonged wound drainage. Because of an initial suspicion that persistent drainage needs to be treated specifically, irrigation and debridement were undertaken in all of the eight cases reported. This secondary procedure occurred at an average of 12.5 days after the initial operation. Twenty-five percent of patients proved to have a positive joint culture at the time of irrigation and debridement, although all cases were treated successfully with adjuvant antibiotics. The success of reopening without introducing infection is of particular note. No morbidity from early irrigation and debridement was experienced, and the authors recommend this procedure for wounds that drain persistently after TKA. The authors hypothesize that recognizing this potential and acting upon it may prevent some chronic drainage problems from becoming true, established infections.(ABSTRACT TRUNCATED AT 250 WORDS)