Functional and Radiological Outcomes of Surgically Treated Coxa-vara in Children

Abstract

Background: Coxa vara is a condition in which the neck-shaft angle of the femur decreases below its normal value (<110 degrees) based on age. The deformity can be primarily caused by a congenital defect of the femoral neck cartilage or by secondary causes related to skeletal dysplasia, trauma, infection, and pathological bone disorders. The surgical treatment aims to restore the normal anatomy, thereby improving the mechanics and function of the hip joint. Generally, the HE angles should be corrected to <35 to 40 degrees, converting the shear forces into compressive forces. Our study aims to report the surgical outcome of coxa vara with various pathologies using radiographic measurement and functional scoring. Methods: Thirty-eight hips in 28 patients who underwent surgery for treatment of coxa-vara from 2013 to 2022 were included. Radiographic parameters like Hilgenreiner-epiphyseal angle and neck-shaft angle were assessed preoperatively and at the latest follow-up. Harris hip score was used for functional outcome. Results: The mean age was 11.13 (5 to 18). The average follow-up was 48 (ranging from 24 to 96) months. The mean preoperative neck-shaft angle was 82 degrees, and the Hilgenreiner-epiphyseal angle was 71 degrees. At the latest follow-up, the mean neck-shaft angle was 127 degrees, and the Hilgenreiner-epiphyseal angle was 33 (P<0.001). The Harris hip score improved from 63 preoperatively to 92 at the latest follow-up (P<0.001). There was no recurrence of deformities at the mean follow-up of 37.87 months. Four complications occurred with k-wire fixation in whom revalgus osteotomy was done. Conclusions: Surgical correction of coxa vara in various pathologies can be done successfully with the Hilgenreiner-epiphyseal angle corrected to ≤ 35 degrees or the neck shaft angle corrected to >110 degrees to prevent deformity recurrence. The majority of the patients reported improvement in hip function. However, a longer-term follow-up is required to determine further outcomes regarding the recurrence of the deformity.