Guide growth with transphyseal medial malleolus screw for the treatment of ankle valgus deformity in children / 中华骨科杂志

ABSTRACT

Objective:To explore the effectiveness of medial malleolus screw epiphyseodesis for pediatric ankle valgus correction and calculate the correction rate, and analyse the influence factors on deformity correction and the risk factors of deformity recurrence after screw removal.Methods:Medical records and radiographs of patients undergoing screw hemiepiphyseodesis of the medial physis of the distal tibia for ankle valgus between Jan 2011 and Dec 2020, at a single pediatric orthopedic department were retrospectively analyzed. A total of 41 patients (49 ankles) were included in following study, including 28 male patients and 13 female patients; with 24 left sides and 25 right sides. Median age at surgery was 10.75 (4.5, 13.9) years, and median follow-up time was 27 (12, 64) months. According to the clinical diagnosis hereditary multiple exostoses were 23 ankles, fibula hemimelia were 5 ankles, tibia hemimelia were 2 ankles, endochondromatosis were 5 ankles, neurofibromatosis were 5 ankles, traumatic fracture were 6 ankles, and fibrous dysplasia were 3 ankles. The lateral distal tibial angle (LDTA) was measured on ankle weight-bearing X-ray to evaluate the deformity correction. Malhotra classification was used to describe shortening of the fibula at the ankle.Results:Eventually effective correction were obtained in 36 ankles, with an overall effective rate of 73.5%. Screw type (partial-thread or full-thread), screw length (whether to the contralateral cortex), washer used, clinical diagnosis, and age are not independent risk factors for effective correction. Multiple linear regression analysis ( R 2=0.67) was applied for postoperative correction amplitude in effective correction cases, and the length of correction time ( P<0.001), clinical diagnosis ( P=0.013) and preoperative LDTA ( P=0.002) were significant predictive factors after adjusting for age differences. One-way ANOVA were used to compare data between different clinical diagnosis, showed a significant difference in the mean postoperative correction rate ( F=5.05, P=0.003). Conclusion:Medial malleolus screw epiphyseodesis is an effective and reliable method for the treatment of ankle valgus deformity in children; different clinical diagnosis can produce significant differences in the correction rate of ankle valgus deformity.