Low annual revision rate in ankle distraction for ankle osteoarthritis: A systematic review and meta-analysis

Ankle osteoarthritis severely impacts patients' mental and physical quality of life. Besides total ankle replacement and ankle arthrodesis, ankle distraction has been shown to be a promising alternative. The primary aim of the present study was to determine the annual revision rates (ARRs) after ankle distraction. The secondary aim was to obtain an overview of patient-reported outcome measures and functional outcomes.

A literature search until November 2023 was performed. Methodological quality was assessed using the methodological index for non-randomised studies criteria. Primary outcome was the ARR which was log-transformed and pooled using a random effects model. Secondary outcomes were pooled using a simplified pooling technique and included the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale (AOFAS), range of motion (ROM) and post-operative complications.

The literature search resulted in 287 articles, of which 10 studies, comprising 602 patients, were included. The patients had a pooled mean age of 47 years (range of means: 40-68) and a mean follow-up of 35 months (range of means: 24-48). The overall methodological quality was moderate to fair. The pooled ARR after ankle distraction was 4% (95% confidence interval [CI], 3%-7%). Pooling of AOFAS showed mean 26-point improvement (from 54 to 80). Additionally, ROM dorsiflexion improved at 5°, and the plantarflexion remained at 31°. The overall complication rate was 41% (95% CI, 35%-48%), of which 77% (95% CI, 67%-85%) were pin-tract infections.

Ankle distraction results in an ARR of 4% (95% CI, 3%-7%) with clinically relevant improved AOFAS scores. The overall complication rate is 41% and is mainly attributable to treatable pin-tract infections (77% of recorded complications).

Level IV, Systematic Review and Meta-Analysis.