Minimum 5 Year Follow-Up Evaluation of a Third Generation Fixed Bearing Total Ankle Arthroplasty with an Intramedullary Tibial Component and a Central Suclus Talus

Abstract

Category: Ankle Arthritis Introduction/Purpose: Total ankle arthroplasty (TAA) has been shown to be a viable option in the treatment of end stage ankle arthritis (ESAA). Early reports demonstrated good results with intramedullary fixation implants. Third generation implants of this kind added a central sulcus to the talar component. This is a report of clinical follow up data from a prospectively collected database at a single US institution using a third generation fixed bearing total ankle arthroplasty implant with a stemmed tibial component and a talar component with a central sulcus. To our knowledge, this is the first report of 5 year follow up data for this implant. Methods: Patients undergoing primary TAA at a single institution by one of four fellowship trained orthopedic foot and ankle surgeons with a third generation fixed bearing implant consisting of an intramedullary stemmed tibial component and a sulcus talus that were at least 5 years postoperative were reviewed from a prospectively collected database. These patients were followed at regular intervals with history, physical examination and radiographs; multiple patient reported outcomes (PRO) measures were obtained. Primary outcomes included implant survivability and PRO scores. Secondary outcomes included coronal plane radiographic alignment (Medial distal tibial articular angle (MDTA) and talar tilt angle (TTA)), evaluation for osteolysis, and failure mode when applicable. All reoperation events were recorded using the Canadian Orthopedic Foot and Ankle Society (COFAS) Reoperations Coding System (CROCS). Results: 121 TAA with this implant were performed in 119 patients between 2010 and 2013; 64 met inclusion criteria. The mean age at surgery was 61.3 ± 10.0 years (range 38.7-84.3). The mean duration of follow up for living patients that retained both initial components at final follow-up was 6.1 ± 0.9 years (range 4.7 – 8.1 years). 26.6% of ankles had a preoperative MDTA and/or TTA greater than 10 degrees. There were 6 (9.4%) failures that occurred at a mean 2.0 ± 1.4 years postoperative. Two failures were due to deep infection. Only one failure was related to tibial component subsidence. One patient is currently scheduled for revision due to talar component subsidence. Conclusion: This cohort of TAA patients with minimum 5 year follow up using a third generation fixed bearing implant demonstrates acceptable implant survival, improved patient reported outcomes scores and maintenance of coronal plane alignment. These data also suggest tolerance of a larger preoperative deformity with improved implant design. To our knowledge, this is the first report with 5 year data on this implant. Continued follow up and reporting is needed to ensure that these favorable outcomes are maintained. Additionally, further investigation on acceptable coronal plane alignment correction with TAA is needed to determine the possible limitations of this procedure.