Ossification of the Ligamentum Flavum at the Thoracic and Lumbar Region in an Achondroplastic Patient

Achondroplasia, a genetic disorder of bone growth, produces specific clinical features of the extremities and spine. Spinal stenosis, seen in patients with achondroplasia, is a congenital disorder related to premature fusion of the pedicles to the lamina. It can be caused by ossification of the ligamentum flavum, which is rare in patients with achondroplasia. We report a rare congenital spinal stenosis with ossification of the ligamentum flavum and thoracolumbar kyphosis deformity in a 24-year-old man with dwarfism and achondroplasia. He was treated with posterior instrumentation and decompression with a wide laminectomy. Treatment of the deformity and the rare condition of ligamentum flavum in a patient with achondroplasia resulted in improved neurologic status and symptoms. To our knowledge, this is the first case report including treatment for both the deformity and thoracic and lumbar ossified ligamentum flavum lesion in a patient with achondroplasia.