Comparison of Intermediate-term Outcomes of Total Ankle Arthroplasty in Primary and Ligamentous Post-traumatic Osteoarthritis.

BACKGROUND

Ankle ligamentous injuries without fracture can result in end-stage ligamentous post-traumatic osteoarthritis, which may cause ligamentous imbalance after total ankle arthroplasty (TAA). However, outcomes of TAA in these patients are not well known. The purpose of this study was to evaluate intermediate-term clinical and radiographic outcomes of TAA in patients with ligamentous post-traumatic osteoarthritis and compare them with results of TAA for patients with primary osteoarthritis.

METHODS

We enrolled 114 patients (119 ankles) with consecutive primary TAA using HINTEGRA prosthesis at a mean follow-up duration of 6.0 years (range, 3-13). We divided all patients into 2 groups according to the etiology of osteoarthritis: (1) primary osteoarthritis group (69 ankles) and (2) ligamentous post-traumatic osteoarthritis group (50 ankles).

RESULTS

There was no significant intergroup difference in mean Ankle Osteoarthritis Scale (AOS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, Short Form-36 Physical Component Summary, visual analog scale pain score, ankle range of motion, or complications at the final follow-up. However, the final tibiotalar angle was less corrected to 4.2 degrees in the ligamentous post-traumatic osteoarthritis group compared to 2.7 degrees in the primary osteoarthritis group (P = .001). More concomitant procedures were required at the index surgery for the ligamentous post-traumatic osteoarthritis group (P = .001). The estimated 5-year survivorship was 93.4% (primary osteoarthritis group: 91.3%; ligamentous post-traumatic osteoarthritis group: 95.8%).

CONCLUSIONS

Clinical outcomes, complication rate, and 5-year survivorship of TAA in ankles with primary and ligamentous post-traumatic osteoarthritis were comparable with intermediate-term follow-up. Our results suggest that TAA would be a reliable treatment in ankles with ligamentous post-traumatic osteoarthritis when neutrally aligned stable ankles are achieved postoperatively.

LEVEL OF EVIDENCE: Level III, retrospective cohort study.