Total Ankle Arthroplasty Results Using Fixed Bearing CT-Guided Implants in Post-Traumatic Versus Non-Traumatic Arthritis

CATEGORY: Ankle; Ankle Arthritis; Trauma INTRODUCTION/PURPOSE: The majority of ankle osteoarthritis are post-traumatic in etiology. Previous studies have shown that patients with post-traumatic ankle osteoarthritis are less satisfied, experience significantly more pain during normal activities and have higher revision rates. However, these studies were performed with older generation implants. The objective of this study was to compare patients hat had undergone total ankle arthroplasty secondary to either post-traumatic or non-traumatic etiologies using patient specific, third generation fixed bearing implants and compare clinical as well as radiographic outcomes. METHODS: A retrospective chart review was conducted on 41 patients who had undergone total ankle arthroplasty using a third- generation fixed bearing implant with CT-based patient specific cutting guides from July 21, 2015 to December 13, 2017 performed by 2 foot and ankle surgeons. Demographic and operative data was collected. Etiology was determined based on clinical notes, operative notes, and x-rays. Clinical outcomes were obtained using the Foot and Ankle Ability Measure questionnaire. Radiographic assessment of the coronal and sagittal alignments were carried out to assess implant migration or loosening. RESULTS: We had 26 patients in the post-traumatic group and 15 in the non-traumatic group with a mean follow-up of 32.5 months and 30.4 months respectively. There was no significant difference between both groups in terms of FAAM ADL subscore with the post-traumatic group did slightly better with 7 patients scoring ‘nearly normal’ (26.9%) and 18 patients scoring ‘normal’ (69.2%). Whereas in the non-traumatic group 5 patients score ‘nearly normal’ (33.3%) and 9 patients score ‘normal’ (60%). In terms of the self-rated subjective functioning score, mean score of 79.2% and 73.4% respectively. On radiographs, there was no subsidence or significant implant movement for both groups at mean follow-up of 28.3 months for the post-traumatic group and 26.3 months for the non-traumatic group. CONCLUSION: Unlike in previous studies in older implants where clinical outcomes were worse in post-traumatic ankle arthritis, our study showed that those receiving total ankle arthroplasty due to post traumatic osteoarthritis do slightly better than those with non-traumatic osteoarthritis, with more patients reporting normal levels of activity. These results may help quantify improvements in newer generation patient specific implants as well as to gain insight into how different implant designs affect post- operative outcomes based on etiology of ankle osteoarthritis.