Effect of Preoperative Deformity on Arthroscopic and Open Ankle Fusion Outcomes.

INTRODUCTION

Coronal deformity is considered a relative contraindication for arthroscopic ankle fusion. This study assessed whether preoperative coronal ankle joint deformity influenced the outcome of arthroscopic ankle fusion.

METHODS

Ninety-seven patients had 62 arthroscopic and 35 open ankle fusions between 2005 and 2012. Clinical outcomes were prospectively recorded with use of the Ankle Osteoarthritis Scale (AOS) and Ankle Arthritis Scale (AAS) preoperatively and at 6, 12, and 24 months and final follow-up. Radiological alignment was measured using the tibiotalar angle, the tibial plafond angle, the lateral talar station, and the lateral tibiotalar angle. Both groups had the same demographics.

RESULTS

Preoperative deformity was the same regarding sagittal alignment and overall coronal alignment, but the arthroscopic group had less tibial deformity (tibial plafond angle range 0-19 degrees vs 0-43 degrees). At final follow-up, the mean AOS was 34.2 for arthroscopic (95% confidence interval [CI], 23.3-45.2) vs 33.9 for open (95% CI, 17.8-49.9). The AAS at final follow-up was 26.0 for arthroscopic (95% CI, 21.0-31.0) vs 27.5 for open (95% CI, 19.7-35.2). Both groups had the same tibiotalar angle, lateral talar station, and lateral tibiotalar angle at follow-up. Regression analyses revealed no influence of type of surgery, preoperative deformity, postoperative radiological alignment, age, sex, body mass index, smoking status, etiology of the arthritis, and need for bone grafting on outcome scores (all P > .05).

CONCLUSION

Arthroscopic and open ankle fusion yielded equivalent results for both patient-reported outcome measure and radiographic alignment in patients with coronal and sagittal joint deformity. Patients with higher tibial plafond angles more often underwent open fusion.

LEVEL OF EVIDENCE

III, comparative series.