Outcome after knee arthrodesis for failed septic total knee replacement using a monolateral external fixator

Purpose. To evaluate the pain level and patient satisfaction as well as the fusion and infection eradication rates after knee arthrodesis using a monolateral external fixator for failed septic total knee replacement (TKR). Methods. Records of 10 male and 11 female consecutive patients aged 70 to 88 (mean, 81) years who underwent knee arthrodesis using a monolateral external fixator for failed septic TKR were retrospectively reviewed. Each patient had undergone a mean of 3.4 (range, 1-15) procedures. The infection eradication rate, fusion rate, time to achieve fusion, pain level, patient satisfaction, and health-related quality of life were evaluated. Results. Infection was eradicated in 18 (86%) of the 21 patients, whereas fusion was achieved in 17 (81%) of the 21 patients after a mean of 10.3 (range, 4-16) months. Those who did and did not achieve fusion differed significantly in terms of the mean pain score (2.3 vs. 6.4, p=0.031). Compared with age-matched Spanish general population, patients aged >75 years fared significantly worse in terms of the mean physical summary component score (40.7 vs. 34.9, p=0.001). Among those who achieved fusion, 82% were very or somewhat satisfied; none was very dissatisfied. Among those who did not achieve fusion, 75% were very or somewhat dissatisfied. Conclusion. Knee arthrodesis using a monolateral external fixator for failed septic TKR achieved high fusion and infection eradication rates, despite the extended time needed. When fusion is achieved, patients had good pain relief and satisfaction.