Risk Factors of Subtalar Arthroereisis for Progressive Collapsing Foot Deformity: A Retrospective Analysis of 236 Cases.

Purpose: Although subtalar arthroereisis (SA) with HyProCure is increasingly utilized for progressive collapsing foot deformity (PCFD), evidence regarding risk factors for complications remains limited. This study aimed to analyze the influencing factors and correlations of sinus tarsi pain and implant removal in PCFD patients after SA utilizing the HyProCure device.

Methods: A retrospective study was conducted involving 223 patients (236 ft) diagnosed with PCFD who underwent SA from June 2015 to June 2023. General data and surgical data such as patient gender, age, body mass index (BMI), surgical side, any adjunctive surgeries, length of stay, HyProCure size, and HyProCure depth were collected. Complications were also recorded. Statistical analysis included normality assessment, inter-group comparisons (t-tests for normal quantitative data, Mann-Whitney U for non-normal data, and chi-square for categorical variables). Spearman correlation analyzed factors associated with sinus tarsi pain and implant removal. Binary logistic regression identified risk factors.

Results: From 2015 to 2023, a total of 60 cases with sinus tarsi pain, with an incidence rate of 25.42%. Spearman correlation analysis showed that sinus tarsi pain was positively correlated with BMI (r = 0.159, p = 0.014), length of stay (r = 0.165, p = 0.011), and HyProCure depth (r = 0.501, p < 0.01). HyProCure removal was positively correlated with HyProCure depth (r = 0.521, p < 0.01) and sinus tarsi pain (r = 0.700, p < 0.01). In the analysis of sinus tarsi pain, the primary risk factor in patients with PCFD was identified as length of stay (OR = 1.456, 95% CI 1.113-1.904) and HyProCure depth (OR = 2.156, 95% CI 1.690-2.750), both of which were statistically significant (p < 0.05). Among the cases of sinus tarsi pain, 36 patients underwent HyProCure removal, leading to an incidence rate of 15.25%. Regarding the removal of HyProCure, the primary risk factor identified was HyProCure depth (OR = 2.531, 95% CI 1.849-3.463), which was statistically significant (p < 0.05). In particular, no significant correlation was observed between HyProCure size and sinus tarsi pain or implant removal (p > 0.05).

Conclusion: In patients with PCFD, length of stay was correlated with the incidence of sinus tarsi pain. Additionally, HyProCure depth was linked to both the incidence of sinus tarsi pain and HyProCure removal. Our research suggests that the prognosis is better for PCFD patients with a shorter length of stay and a reduced HyProCure depth.

Level of evidence: Level III, Retrospective Comparative Study.