Surgical treatment of hallux valgus associated with flexible flatfoot during growing age

Purpose: During growth, hallux valgus could present associated with flatfoot. Considering the current disagreement about correction of hallux valgus during growth and the lack of reports about simultaneous correction of hallux valgus associated with flexible flatfoot, we present simultaneous treatment of both deformities during growth combining subtalar arthroeresis and SERI first metatarsal osteotomy, reporting results at an average five-year follow-up. Methods: Thirty-two children (64 feet, age range 8–12 years) affected by hallux valgus associated with flexible flatfoot underwent surgical treatment combining SERI first metatarsal osteotomy and subtalar arthroereisis with bioabsorbable endorthotic implant. Clinical evaluation was summarized with AOFAS score, and standard standing radiographs were performed. Results: AOFAS score ranged from 86 ± 2 to 98 ± 2 (hindfoot) and from 80 ± 4 to 98 ± 2 (forefoot). HVA ranged from 21° ± 2 to 5° ± 2, IMA from 14° ± 2 to 7° ± 2, DMAA from 18° ± 2 to 2° ± 2, and Meary’s angle from 162° ± 11 to 175° ± 4. Complications included one case of delayed wound healing, inflammatory skin reaction around the outlet of the percutaneous Kirschner wire in two cases, displacement of the endorthotic implant in one case, and a second surgery to replace the implant. Conclusions: SERI osteotomy and subtalar arthroereisis resulted in an effective, technically simple and easily combined approach, with a high rate of good results and low rate of complications at mid-term follow-up. These techniques performed simultaneously represent a viable option in case of hallux valgus associated with flexible flatfoot during growth. Nevertheless, considering the limitations of this study, we believe that a larger case series and a longer follow-up should be desirable.