Long-term results of various treatment options for infected total knee arthroplasty.

Of 73 infected total knee arthroplasties treated from 1973 through 1984, the outcome of various management options revealed that solid arthrodesis was obtained in 70%. Fifteen percent of those with a solid fusion had residual pain or even recurrence of infection. Aggressive debridement was successful in eight of ten (80%). Long-term follow-up results show reimplantations were successful in eight of 15 (53%) but were functionally successful in only five of 15 (33%). A treatment plan based on functional considerations follows. For acute infections a very aggressive initial debridement followed by primary closure over an antibiotic-soaked pack is carried out. The prosthesis is left in place if at all possible and if the bone-cement interface has not demonstrated loosening. The knee is debrided every two or three days until negative cultures are obtained. Antibiotic beads are then inserted, with reexploration at three weeks with new cultures. Parenteral antibiotics are given for a three-week period initially. If two successive surgical debridements fail to reveal a positive culture, the knee is closed and rehabilitation is begun. For chronic infections, the recommendations of Wilde and Ruth are followed, employing antibiotic-impregnated beads and spacers with staged debridements similar to the method described above. Finally, an accurate definition of the true value of any of these options is predicated on long-term follow-up studies, since options that seemed promising as an initial procedure have proved disappointing as more experienced and longer follow-up study is obtained.