Natural history of scoliosis in spastic cerebral palsy

Background Although the frequent occurrence of scoliosis in patients who have spastic cerebral palsy is well known and surgical treatment has often been recommended for these patients, little is known about the natural history of scoliosis in this population. We aimed to clarify the natural history of scoliosis from childhood through to adulthood and provide objective data on proper surgical indications for such patients. Methods The participants were 37 institutionalised patients with severe spastic cerebral palsy and scoliosis. All the participants had a series of radiographs taken, starting at a mean age of 7•8 years; they were followed up for an average of 17•3 years. We retrospectively reviewed radiographs and assessed the effect of five factors on progression of scoliosis: sex, degree of spasticity, initial physical capability, pattern of spinal curve, and location of curve. Findings Scoliosis usually started before the age of 10 years and progressed rapidly during the growth period. In many cases, even after growth had ended, continuous progression was seen. The mean magnitude of the curves at final examination was 55° (Cobb angle). In 11 (85%) of 13 patients who had a spinal curve of more than 40° before age 15 years, the scoliosis progressed to more than 60° by the time of the final examination. Meanwhile, in only three (13%) of 24 patients who had a curve of less than 40° at age 15 years, did the scoliosis progress to more than 60°. Severe scoliosis (≥60°) developed predominantly in those who had total body involvement (67%), were bedridden (100%), or had throacolumbar curves (57%). Interpretation The risk factors for progression of scoliosis in spastic cerebral palsy are: having a spinal curve of 40° before age 15 years; having total body involvement; being bedridden; and having a thoracolumbar curve. Patients with these risk factors might benefit from early surgical intervention to prevent progression to severe scoliosis.