Is Kidner procedure necessary during subtalar arthroereisis for pediatric flexible flatfoot that combined with symptomatic type 2 accessory navicular? A retrospective comparative study.

ABSTRACT

BACKGROUND: Kidner procedure is thought to be able to eliminate the medial foot pain and contribute to restoring the medial longitudinal foot arch, making it particularly suitable for surgical treatment of pes planus that combined with symptomatic type 2 accessory navicular (AN). However, controversy remains, and the clinical evidence is still lacking. The aim of the current study is to verify the necessity of Kidner procedure during subtalar arthroereisis (STA) for pediatric flexible flatfoot (PFF) that combined with symptomatic type 2 AN. METHODS: Forty pediatric patients (72 feet) who had undergone STA for flexible flatfoot and were also diagnosed with symptomatic type 2 AN concomitantly were reviewed retrospectively and divided into two groups (STA + Kidner vs STA alone). The visual analog scale (VAS), the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale, the Oxford ankle foot questionnaire for children (OAFQC), and the radiographic parameters that quantifying pes planus were evaluated as primary outcomes. Secondary outcomes included the incidence of complications. RESULTS: There were 35 feet in the STA + Kidner group and 37 feet in the STA alone group, with mean follow-up periods of 2.7 years and 2.1 years, respectively. The VAS, AOFAS, OAFQC scores and radiographic parameters presented no significant difference between the two groups both preoperatively and at final follow-up (P > 0.05 for each). The complications of STA surgery occurred equally in both groups, and Kidner procedure could lead to more incision problems (22.9% vs. 2.7%) and a longer time to return to activity. CONCLUSION: Kidner procedure may be unnecessary during surgical treatment of PFF that combined with painful type 2 AN. Correcting the PFF while leaving the AN alone has a high possibility of relieving the pain in the AN region, and tibialis posterior tendon (TPT) rerouting hardly aids in reconstruction of the medial foot arch. LEVEL OF EVIDENCE III.