Restoration of ankle alignment is thought to be critical in total ankle arthroplasty (TAA) outcomes, but previous research is primarily focused on coronal alignment. The purpose of this study was to investigate the sagittal alignment of the talar component. The talar component inclination, measured by the previously-described gamma angle, was hypothesized to be predictive of TAA outcomes. A retrospective review of the Canadian Orthopaedic Foot and Ankle Society (COFAS) database of ankle arthritis was performed on all TAA cases at a single center over a 11-year period utilizing one of two modern implant designs. Cases without postoperative x-rays taken between 6 and 12 weeks were excluded. The gamma angle was measured by two independent orthopaedic surgeons twice each and standard descriptive statistics was done in addition to a survival analysis. The postoperative gamma angles were analyzed against several definitions of TAA failure and patient-reported outcome measures from the COFAS database by an expert biostatistician. 109 TAA cases satisfied inclusion and exclusion criteria. An elevated postoperative gamma angle higher than 22 degrees was associated with talar component subsidence, defined as a change in gamma angle of 5 degrees or more between postoperative and last available followup radiographs. This finding was true when adjusting for age, gender, body mass index (BMI), and inflammatory arthritis status. All measured angles were found to have good inter- and intraobserver reliability. Surgeons should take care to not excessively dorsiflex the talar cuts during TAA surgery. The gamma angle is a simple and reliable radiographic measurement to predict long-term outcomes of TAA and can help surgeons counsel their patients postoperatively.
We present a series of 16 patients who have had a failed ankle arthroplasty converted to an ankle arthrodesis using a surgical technique of bone grafting with internal fixation. We describe our technique using tricortical autograft from the iliac crest to preserve length and an emphasis is placed on maintaining the malleoli and subtalar joint. A successful fusion was achieved in all cases with few complications. Our post operative AOFAS improved to a mean of 70 with good patient satisfaction and compares well to other published series. From this series and an extensive review of the literature we have found fusion rates following failed arthroplasty in patients with degenerative arthritis to be very high. In this group of patients a high fusion rate and good clinical result can be achieved when the principles of this surgical technique are adhered to. It would appear that a distinction should be made between treating patients with poor quality bone and more extensive bone loss, as is often the case with rheumatoid patients; and the patients with a non inflammatory arthropathy and better bone quality. The intramedullary nail would appear to be the preferred option in patients with inflammatory polyarthropathy where preservation of the subtalar joint is probably not of relevance as it is usually extensively involved in the disease process, and a higher rate of complications can be anticipated with internal fixation.
We present a series of 16 patients treated between 1993 and 2006 who had a failed total ankle replacement converted to an arthrodesis using bone grafting with internal fixation. We used tricortical autograft from the iliac crest to preserve the height of the ankle, the malleoli and the subtalar joint. A successful arthrodesis was achieved at a mean of three months (1.5 to 4.5) in all patients except one, with rheumatoid arthritis and severe bone loss, who developed a nonunion and required further fixation with an intramedullary nail at one year after surgery, before obtaining satisfactory fusion. The post-operative American Orthopaedic Foot and Ankle Society score improved to a mean of 70 (41 to 87) with good patient satisfaction. From this series and an extensive review of the literature we have found that rates of fusion after failed total ankle replacement in patients with degenerative arthritis are high. We recommend our method of arthrodesis in this group of patients. A higher rate of nonunion is associated with rheumatoid arthritis which should be treated differently.
