Determining the change in functional outcome score and CT fusion ratio following arthroscopic subtalar arthrodesis: A...

This study aimed to evaluate the change in foot and ankle functional outcome scores and the CT fusion ratio after Posterior Arthroscopic Subtalar Arthrodesis (PASTA) in patients with isolated subtalar arthritis.

A prospective observational study was conducted from March 2021 to March 2023, enrolling 20 patients (12 males, 8 females) with posttraumatic or degenerative isolated subtalar arthritis. Functional outcomes were assessed at 6 weeks, 3 months, and 6 months postoperatively using AOFAS, FADI, FAOS, and VAS scores. Fusion was assessed via CT scan at 6 months to calculate the CT fusion ratio.

Functional outcomes significantly improved over time. The mean AOFAS score increased from 48.0 ± 8.53 preoperatively to 83.8 ± 9.73 at 6 months. The mean FADI and FAOS scores improved from 42.85 ± 7.11 and 43.35 ± 8.78 preoperatively to 86.5 ± 11.38 and 86.75 ± 11.15, respectively, at 6 months. The VAS score decreased from a mean of 4.9 ± 0.89 at 6 weeks to 1.6 at 6 months. The mean CT fusion ratio at 6 months was 65.39 % ± 13.98 %. Only one patient showed a fusion ratio below 33 % and later required ankle arthrodesis. A significant positive correlation was observed between CT fusion ratio and AOFAS (ρ = 0.64, p = 0.002), FADI (ρ = 0.55, p = 0.010), and FAOS (ρ = 0.45, p = 0.043). Most patients rated satisfaction as "excellent" at final follow-up. Minor complications such as transient pain and swelling were observed but resolved over time.

Arthroscopic subtalar arthrodesis significantly improved functional outcomes and demonstrated a high CT fusion rate with minimal complications in patients with isolated subtalar arthritis.

Level III.