Factors associated with radiographic correction of the foot after medialising calcaneal osteotomy in children with symptomatic flexible flatfoot

The objective is to determine the preoperative factors associated with the ability of medialising calcaneal osteotomy (MCO) to restore radiographic parameters of the foot to within the accepted ranges in children with symptomatic flexible flatfoot (FF). Twenty-five children (20 boys and 5 girls) with 45 FFs (23 right and 22 left) who underwent MCO were enrolled. The patients were classified according to whether the lateral talus–first metatarsal (Lat-TMT1) and the talar declination (TD) angles were maintained in an acceptable range (±2 SD) during the study period. Preoperative parameters potentially related to unacceptable Lat-TMT1 and TD angles were identified using univariate and multivariate logistic regression analyses. Potential parameters were further evaluated using the receiver operating characteristic curve to identify an appropriate cutoff point. The functional outcome was evaluated using the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS-AHFS). The average age at the time of the procedure was 9.3 ± 2.5 years. The mean duration of follow-up was 3.5 ± 2.8 years. The average medialisation of the calcaneal tuberosity was 30.3%. Sixteen of 25 patients (64%) had foot radiographs showing acceptable Lat-TMT1 and TD angles. The postoperative AOFAS-AHFS was 94.8 ± 9.8. Four parameters (talar head uncovering index, lateral talus–first metatarsal, lateral talus–calcaneus, and TD angles) were identified by univariate analysis. A preoperative Lat-TMT1 angle >26° as the cutoff point showed high sensitivity and specificity associated with unacceptable radiographic results. In conclusion, a multivariate model could not identify parameters linked to unacceptable radiographic results. Preoperative radiographic parameters that exceed the cutoff points indicate a questionable suitability of the operation. Level of evidence Level IV – prognostic, retrospective case series.