Subtalar Arthroereisis in Treatment of Pediatric Flexible Flat Foot using Subtalar Sinus Tarsi Implants

This study aimed at evaluating the efficacy and safety of arthroereisis of subtalar joint using subtalar sinus tarsi implant in the cure of flexible flatfoot in pediatric population.

Materials and Methods: A prospective case series conducted on 30 feet with flexible flatfoot deformity. Their follow up was for 10 to 20 (15 ± 3.5) months. Clinical assessment was done using scoring system (AOFAS), Radiological assessment was done using TNA& TMA to asses talonavicular coverage and talar first metatarsal angle.

Results: The mean functional (AOFAS) Ankle-Hind foot score improved from 64.3 ± 8.26 (43-77) preoperatively to 89.23 ± 5.41 (77-98) postoperatively at last follow up (P value<0.001) using paired t-test as a significance test for evaluation of pre and post-operative AOFAS score. Our results showed median decrease in TMA is 15° (range: 4° to 29°) preoperative to 4° (range : 0° to 17°) at the final follow-up, while TNA showed median decrease from 18° (range : 12° to 45°) preoperative to 5° (range: 1° to 44° ) at the final follow up. The average decrease in both angles was statistically significant (P<0.001). Post-operative complications were detected in 5 patients (16.6%). Two patients (6.6%) developed subclinical infection. Two patients (6.6%) developed severe pain at sinus tarsi (sinus tarsitis) following surgery. One patient (3.3%) developed reactional synovitis followed by loosening of the implant and then extrusion after 3 months Debridement and reinsertion of smaller sized implant have been done.

Conclusion: Subtalar arthroereisis using subtalar arthroereisis implant is suitable for the management of flexible, mild to moderate planovalgus foot deformity.The practice can be carried out in arrangement with other surgical procedures for the adjustment of severe cases.