First metatarsal elevation after subtalar arthroeresis in children with flatfeet

Abstract

BACKGROUND: Arthroereisis of the subtalar joint is a common surgical option for children with flat feet. Along with all the advantages of arthroereisis of the subtalar joint, the indications for surgery, the optimal age for surgical treatment, as well as secondary deformities of the forefoot that occur after treatment are debatable. AIM: The aim of this study was to analyze the frequency and degree of I metatarsal elevation after arthroereisis of the subtalar joint in children. MATERIALS AND METHODS: The study group included 106 patients / 202 feet who were treated at the H. Turner Pediatric Orthopedic Institute for the period from 2015 to 2019. The average age was 11 years (8; 13). Arthroereisis of the subtalar joint was performed in two variants: arthroereisis with a locking screw in the calcaneus 44 patients / 83 feet and arthroereisis with a locking screw in the talus 62 patients / 119 feet. An analysis was made of the incidence of I metatarsal elevation after arthroereisis of the subtalar joint. The relationship between the degree of elevation of the first metatarsal bone and the main clinical and radiological characteristics of the feet at different times after surgical treatment was analyzed. RESULTS: The frequency of elevation of the I metatarsal bone with the use of a calcaneal locking screw was 20.7%, and with the use of a talar locking screw, the frequency is 51.6%. Clinical manifestations of elevation of the I metatarsal bone took place when the amount of elevation was more than 65% of the size of the head of the I metatarsal bone. At a period of 23 years after the operation, elevation of the I metatarsal bone were noted in 15.9%. A statistically significant correlation (Spearman coefficient) was noted between the degree of elevation of the I metatarsal bone and the following parameters: anteroposterior Meary angle (0.360), lateral Kite angle (0.367), lateral Meary angle (0.378), foot arch angle (0.344), tibio-talar angle (0.351), Friedlands index (0.402). CONCLUSIONS: Incidence of the first metatarsal bone elevation reaches 51% of the in patients in the immediate follow-up period after performing arthroereisis of the subtalar joint. Elevation of the first metatarsal bone developed dorsal bunion with an elevation value of more than 65%. The degree of elevation of the first metatarsal bone has a positive correlation with the degree of planovalgus deformity correction. Elevation of the first metatarsal bone tends to decrease up to 15% in the long-term follow-up after surgical treatment.