Long-term results of subtalar arthroereisis for symptomatic flexible flatfoot in paediatrics.

PURPOSE: Subtalar arthroereisis (STA) is a clinical intervention used for the correction of flexible flatfoot (FFF) in the paediatric population. This study aims to evaluate the radiographic, clinical, and patient-reported outcomes of STA for symptomatic FFF in paediatric patients with a minimum follow-up period of nine years.

METHODS

A cohort of 19 patients (38 feet) who underwent STA for FFF treatment between 2011 and 2015 was analyzed. This study featured a minimum follow-up period of nine years and involved comprehensive radiographic measurements. Clinical function assessment included footprint analysis classified using the Viladot classification, the Foot and Ankle Outcome Score (FAOS), and the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale. We calculated the association between preoperative and postoperative angles and functional results. Receiver operating characteristic (ROC) curve analyses were conducted to establish the optimal threshold to predict good clinical outcomes.

RESULTS

The average age at the time of surgery was 11 ± 1.79 years, and the mean duration of follow-up was ten ± 1.4 years. After the surgical intervention, all foot angles showed statistically significant improvements. Normal foot alignment according to the Viladot classification was noted in 71% of patients. Good to excellent functional outcomes, as measured by both the AOFAS-hindfoot score and FAOS score, were reported in 84.2% of patients. Significant correlations were found between the preoperative and postoperative angles and functional results. Based on ROC curve analysis, the cut-off values were determined to be 28.5 degrees for the talonavicular coverage angle, 19.5 degrees for Meary's angle, and 37.5 degrees for the talar declination angle.

CONCLUSION

Our study indicates that STA is an effective procedure for durable deformity correction in paediatric patients with FFF. Restoring the medial longitudinal arch and correcting forefoot abduction are essential for improving functional outcomes. Both preoperative and postoperative angles were significantly associated with functional results, and the identified preoperative cut-off values are helpful for selecting surgical candidates.