Spinal stenosis surgery in pediatric patients with achondroplasia.

OBJECT: Achondroplasia is a hereditary form of dwarfism caused by a defect in endochondral bone formation, resulting in skeletal abnormalities including short stature, shortened limb bones, macrocephaly, and small vertebral bodies. In the pediatric population, symptomatic spinal stenosis occurs at all spinal levels due to the abnormally narrow bone canal. In this study, clinical outcomes were assessed in children with achondroplasia after spinal canal decompression.
METHODS: A retrospective review was conducted involving pediatric patients with heterozygous achondroplasia and symptomatic stenosis after decompressive procedures at the authors' institution within a 9-year period. Measured outcomes included resolution of symptoms, need for repeated surgery, presence of fusion, development of deformity, and complications. Forty-four pediatric patients underwent a total of 60 decompressive procedures. The average patient age at surgery was 12.7 years (range 5-21 years). Forty-nine operations were performed for initial treatment of stenosis, and 11 were performed as revision surgeries on previously operated levels. A large proportion of patients (> 60%) required additional cervicomedullary decompressions, most often preceding the symptoms of spinal stenosis. Of the initial procedures, decompression locations included 32 thoracolumbar (65%), 10 lumbar (20%), four cervical (8%), two cervicothoracic (4%), and one thoracic (2%). Forty-three of the decompressive procedures (72%) included spinal fusion procedures. Of the 11 revisions, five were fusion procedures for progressive deformity at levels previously decompressed but not fused (all thoracolumbar), five were for decompressions of symptomatic junctional stenosis with extension of fusion, and one was for repeated decompression at the same level due to recurrence of symptomatic stenosis.
CONCLUSIONS: Decompression of the spinal canal in pediatric patients with achondroplasia can be accomplished safely with significant clinical benefit. Patients with a history of cervicomedullary compression may be at an increased risk of developing symptomatic stenosis prior to adolescence. Fusion procedures are recommended in patients with a large decompression overlying a thoracolumbar kyphosis to avoid progressive postoperative deformity.