WOFAPS 2025 8th World Congress of Pediatric Surgery

Yangyang Yao, Yanzhou Wang, Tianyou Li, Jiaqi Wang, Xiaoqing Wang

Shandong Provincial Hospital, Jinan, Shandong, China

Purpose: This study evaluates outcomes of temporary hemiepiphysiodesis using eight-plate implants for correcting lower limb angular deformities in children with rare bone diseases.

Method: A retrospective review included 56 children with rare bone diseases treated between 2011–2023. Pre- and postoperative radiographs assessed mechanical axis deviation (MAD), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and lateral distal tibial angle (LDTA). Deformity severity was classified by tibial plateau zones (1–4). Complications were recorded.

Results: The cohort included 31 boys and 25 girls (mean age at surgey: 6.92 years, range: 2–14). Diagnoses included hypophosphatemic rickets (n=38), mucopolysaccharidosis (7), achondroplasia (4), multiple exostoses (3), pseudoachondroplasia (1), metaphyseal chondrodysplasia (1), multiple epiphyseal dysplasia (1), and Shwachman-Diamond syndrome (1). Deformities included bilateral genu varum (36), bilateral genu valgum (19), and mixed unilateral varus/valgus (1). Complete correction occurred in 1 Trevor disease and 7 mucopolysaccharidosis patients. Among hypophosphatemic rickets cases (38), 34 showed partial improvement; 5 required repeat surgery. Improvement was noted in metaphyseal chondrodysplasia, multiple epiphyseal dysplasia, and Shwachman-Diamond syndrome (1 each). Poor outcomes occurred in 2 achondroplasia and 1 pseudoachondroplasia patients. No complications (e.g., implant failure, infection) were reported.

Conclusion: Temporary hemiepiphysiodesis using eight-plate implants is a relatively simple procedure with low surgical risks, allowing immediate weight-bearing postoperatively. Moreover, it can be performed repeatedly in young pediatric patients. The plate and screw fixation remains robust and reliable even in cases of epiphyseal and metaphyseal abnormalities. Hemiepiphysiodesis is effective in managing angular deformities of the lower limbs in children with rare bone disorders, significantly improving lower limb alignment and enhancing mobility. However, the therapeutic effect requires a prolonged duration, typically exceeding two years. The efficacy varies depending on diagnosis and age, with a high likelihood of recurrence necessitating additional surgical interventions.