Arthrodesis after failed knee arthroplasty. A nationwide multicenter investigation of 91 cases.

Ninety-one patients with attempted arthrodesis after failed knee arthroplasty were identified in a prospective nationwide study of knee arthroplasties performed from October 1975 through January 1982 in Sweden. The study included 43 hinged or stabilized, 34 bi- or tricompartment, and 14 unicompartment endoprostheses. Three-fourths of the failures were caused by infections. At follow-up evaluation, two patients had expired from infection and four patients had amputations. Fusion was achieved in only 50% of 108 attempts in 91 knees. Patients with unstable joints had limited function. The fusion rate was relatively high after unicompartment endoprostheses, in cases with sustained rigid fixation, or in cases where infection was brought under control at arthrodesis. Rigid fixation was best achieved with an external double frame or an intramedullary nail. Repeated attempts were worthwhile. Removal of all foreign material, eradication of the infectious lesion, and an arthrodesis performed in a one- or two-stage procedure with insertion of gentamicin beads seemed to be the best way to combat infection. The treatment of prosthetic failures should be referred to centers with special interest in knee arthroplasty.