Early evaluation and treatment of thoracolumbar kyphosis in children with achondroplasia

Abstract

Purpose: Thoracolumbar kyphosis (TLK) is frequently reported in children with achondroplasia. The combination of TLK and the narrow spinal canal in achondroplasia increases the risk of developing symptomatic spinal stenosis. However, there is no consensus on the optimal management of TLK. Methods: This retrospective cohort study evaluated children under four years old with achondroplasia, monitoring TLK every six months. Pathologic TLK was defined as a Cobb angle of 20 degrees or more between T10 and L2. Management involved either a wait-and-see policy, which prohibited unsupported sitting, or bracing. Surgery was reserved for severe progressive TLK or spinal stenosis cases. TLK was evaluated over time. A receiver operating characteristic curve determined the baseline threshold where wait-and-see management failed to resolve TLK below 20 degrees. Multiple linear regression compared bracing versus wait-and-see management for cases exceeding 40 degrees. Results: Sixty-two patients were included, with a median age of 10 months and a median follow-up of 31 months. TLK prevalence decreased from 85% at baseline to 42% at final follow-up. The mean Cobb angle decreased from 31 ± 11 degrees to 22 ± 16 degrees (p < 0.001). The threshold for ineffective wait-and-see management was identified as 33 degrees. Bracing resulted in significantly more TLK reduction than wait-and-see management for cases exceeding 40 degrees (15 degree difference, 95% CI 2–28, p = 0.023). Three patients required surgery. Conclusion: TLK is highly prevalent in achondroplasia, necessitating careful monitoring. A wait-and-see policy with restrictions on unsupported sitting is recommended initially, but early bracing should be considered for more severe cases.