Comparative evaluation of radiographic and pedobarographic outcomes after calcaneal lengthening osteotomy in children with pes planus

This study aimed to evaluate the agreement between radiographic and pedobarographic measurement methods for classifying a normal foot type following calcaneal lengthening osteotomy in children with symptomatic pes planus. Thirty feet from patients (mean age: 15.1 years; range: 11-17 years) with idiopathic symptomatic hypermobile pes planus who had data and over 1 year of follow-up were evaluated. Radiographic assessments were categorized into measurements evaluating the medial longitudinal arch and those assessing calcaneal morphology. Medial longitudinal arch measurements included talocalcaneal, lateral talo-first metatarsal, talohorizontal, calcaneal pitch, talonavicular coverage, anteroposterior talo-first metatarsal, and Moreau-Costa-Bartani angles, while calcaneal measurements included calcaneal length, posterior facet height, Gissane angle, and Böhler angle. Pedobarographic measurements were performed using Arch Index, Footprint Index, and Clarke's angle, and clinical outcomes were assessed using the Oxford Ankle Foot Questionnaire for Children. Cohen's kappa coefficient was used to determine the agreement among the measurement methods in classifying the foot type as 'normal'. Postoperative findings revealed that changes in calcaneal length occurred without deformation of the articular surface. Arch Index exhibited 'almost perfect' agreement with the lateral talo-first metatarsal (k = 0.902) and talohorizontal angles (k = 0.814) and was the only pedobarographic measurement that correlated significantly with all domains of the Oxford Ankle Foot Questionnaire for Children. In contrast, Clarke's angle and Footprint Index did not show agreement with radiographic measurements. Following calcaneal lengthening osteotomy, among the pedobarographic measurement methods, only the Arch Index can be used as an alternative to radiographic measurement methods for classifying normal foot structure.