Arthrodesis of the knee with a long intramedullary nail following the failure of a total knee arthroplasty as the result of infection. Surgical technique.

BACKGROUND: Knee arthrodesis can be an effective treatment option for relieving pain and restoring some function after the failure of a total knee arthroplasty as the result of infection. The purpose of the present study was to review the outcome of a staged approach for arthrodesis of the knee with a long intramedullary nail after the failure of a total knee arthroplasty as the result of infection.

METHODS: We reviewed the results for twelve patients who underwent knee arthrodesis after the removal of a prosthesis because of infection. The study group included seven women and five men who had an average age of sixty-eight years at the time of the arthrodesis. All patients were managed with a staged protocol. Implant removal, débridement, and insertion of antibiotic cement spacers was followed by the administration of systemic antibiotics. Provided that clinical and laboratory data suggested eradication of the infection, arthrodesis of the affected knee with use of a long intramedullary nail was carried out. Clinical and laboratory evaluation and radiographic analysis were performed after an average duration of follow-up of 4.1 years.

RESULTS: Solid union was achieved in ten of the twelve knees. The average time to union was 5.5 months. One patient had an above-the-knee amputation because of recurrence of infection. In another patient, nail breakage occurred three years following implantation. The average limb-length discrepancy was 5.5 cm. The mean Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score improved from 41 to 64 points. None of the seven patients who underwent arthrodesis with a technique involving convex-to-concave reamers had a complication, and the average time to union for these seven patients was shorter than that for the remaining five patients (4.3 compared with 7.4 months).

CONCLUSIONS: We believe that obtaining large surfaces of bleeding contact bone during arthrodesis following staged treatment of an infection at the site of a failed total knee arthroplasty contributes to stability and enhances bone-healing. Staged arthrodesis with use of a long intramedullary nail and convex-to-concave preparation of bone ends provided a painless functional gait with low complication and reoperation rates in this challenging group of patients.