Abstract

Background: Despite recent advances in ankle arthroplasty, ankle arthrodesis is still considered to be the gold standard treatment for end-stage ankle arthrosis. Recent progress in arthroscopic techniques has led to equivalent fusion rates and patient reported outcome measures when compared to open techniques - traditionally the gold standard. We look to add to a growing body of evidence supporting the use of arthroscopic ankle arthrodesis (AAA) in a large single surgeon cohort.

Method: A retrospective clinical and radiographic assessment was conducted on 47 consecutive patients (48 ankles) undergoing AAA by a single surgeon between 2014 and 2019. The primary outcome was time to union, fusion rate, and re-operation rates. Secondary outcomes were preoperative and postoperative coronal and sagittal plane alignment, antero-posterior talar shift (measured as tibial axis to talus ratio), length of stay, followup visits, operation times, complication rates and relation of body habitus and medical comorbidities to fusion rates.

Results: Our cohort demonstrates union rates of 96% with a low incidence of both early and intermediate term complications. Length of stay, analgesic requirements and soft tissue complications all compared favourably to published outcomes in open ankle fusion. We demonstrated that significant corrections in alignment - in both the coronal and sagittal planes can be achieved through arthroscopic techniques. Mean coronal plane alignment of 4.5^° (range 71 to 109, S.D 5.2), mean sagittal plane alignment of 7.1^° (range 97 to 121 S.D 6.5) and mean T:T ratio correction of 6.1% (range 10-53 S.D 9.7) was achieved.

Conclusions: AAA is a safe and reliable procedure with high union rates and low complication rates with outcomes that are at least equivalent to traditional, more invasive open techniques. Our findings are in keeping with an emerging body of evidence supporting the continued use of AAA in ankle arthrodesis, even in the setting of significant deformities.

Keywords: Arthroscopic ankle arthrodesis; Ankle arthrodesis; Coronal plane alignment; Sagittal plane alignment; Ankle fusion; Retrospective cohort study; T:T ratios; Union rates