Ankle Arthrodesis with Structural Grafts Can Work for the Salvage of Failed Total Ankle Replacement

Abstract

Category: Ankle, Ankle Arthritis Introduction/Purpose: Surgical treatment options after failed total ankle replacement (TAR) are limited to revision total ankle replacements, revision bone block interposition arthrodesis, or amputation. In patients where revision TAR is not an option and limb salvage is desired, conversion to an ankle arthrodesis can provide a stable, plantigrade foot. Revision arthrodesis is challenged by significant bone loss with removal of the TAR implant. The purpose of this study was to report midterm outcomes and radiographic results in a single surgeon’s group of patients who have undergone revision ankle arthrodesis with intramedullary nail fixation and structural allograft augmentation following failed TAR. Methods: Institutional review board approval was obtained for this study. A retrospective chart and radiographic review was performed. Patients with a minimum follow-up of 1 year who underwent failed TAR revision with structural femoral head allograft and intramedullary tibiotalocalcaneal (TTC) nail fixation were included. Patients with less than 1-year follow-up and alternative fixation or graft constructs were excluded from the study. Data were collected upon enrollment visit and again at midterm follow-up ranging from 3-7 years post-operatively. Foot Function Index (FFI), American Orthopaedic Foot & Ankle Society (AOFAS) outcomes scores and radiographs were obtained at each visit. Primary outcomes of interest were the rate of limb salvage and patient reported outcome scores. Secondary outcomes include limb length correction and the fate of the structural allograft. Results: Five patients were available for enrollment. Average age at surgery was 63.2 (range 56-69) years. Enrollment visits averaged 1.68 years post-operative (range 0.95 - 3.78). Midterm follow-up was at an average of 5.2 years (range 4.7-5.6). Upon enrollment average FFI was 34.82 (range 8.82-75.88) and at midterm follow-up was 20.42 (range 0-35.38). AOFAS scores upon enrollment averaged 66.6 (range 61-77) and at midterm follow-up averaged 70.33 (range 54-88). Radiographic results show union in 4 of 5 patients at enrollment and in 2 of 3 patients upon midterm follow-up. Average limb length discrepancy at enrollment was 1.4 cm (range 0.5 - 2.0) and 1.6 cm (range 0.2 – 2.4) at midterm follow-up. Conclusion: Conversion of failed TAR to TTC fusion with femoral head allograft is a salvage technique that can lead to a functional arthrodesis and limb salvage in a situation where options are challenging. Our results show continued improvement in patient reported outcomes scores moving from short-term to midterm follow-up with preservation of limb length and no trend towards structural allograft resorption.