Natural History of Untreated Scoliosis in beta-Thalassemia.

STUDY DESIGN: A prospective study was performed.

OBJECTIVES: To investigate the natural history of untreated scoliosis in beta-thalassemia patients in a 10-year period.

SUMMARY OF BACKGROUND DATA: Several previous studies have demonstrated the bone deformities, particularly the high incidence of scoliosis, that is associated with beta-thalassemia. However, little is known about the evolution of scoliosis curvatures, and almost nothing is known about the natural history of this type of scoliosis and its associated lateral spinal curvatures.

METHODS: From a group of 115 patients with beta-thalassemia who were evaluated for scoliosis 10 years ago, 43 patients (37%) were re-evaluated 10 years later to study the evolution of the untreated scoliosis and lateral spinal curvatures. Scoliosis, thoracic kyphosis, thoracolumbar kyphosis, and lumbar lordosis were measured both in the initial and last observation and were compared with each other. All changes in scoliosis curve location, direction, and rate of resolving, as well as the changes in the magnitude of the lateral spine curves, were recorded.

RESULTS: Scoliosis curves of more than 5 degrees were present in 34 (79%) of the 43 patients who were followed. Scoliosis progressed but was not statistically significant in 12% of the patients with thalassemia in a 10-year span. Ten years ago, 12 patients (28%) showed scoliosis of 10 degrees to 14 degrees, whereas in the last evaluation, 15 patients (35%) had scoliosis of 10 degrees to 19 degrees. The S-shaped scoliosis curve pattern was the most common (29%). In 10 years, the scoliosis curve pattern remained unchanged in 38% of the patients, and it changed in 38%, whereas 24% of the minor curves (5-9 degrees ) showed spontaneous "self-resolving" character. In the last evaluation, there were seven patients (16%) with new cases of scoliosis de novo. There was no sex-related predominance in prevalence of scoliosis in this series. There was a significant skeletal mature retardation in the patients with beta-thalassemia. There was a significant increase of thoracic and thoracolumbar kyphosis and a decrease of lumbar lordosis. The changes in the sagittal profile were not correlated to scoliosis in this group of patients.

CONCLUSIONS: Scoliosis in beta-thalassemia appeared with increased prevalence but with small curves of 5 degrees to 19 degrees that did not need active orthopedic treatment. However, a few cases progressed to curves less than 20 degrees, and only one patient (2.9%) showed a severe curve that showed much progression. The behavior of scoliosis in beta-thalassemia differs significantly from that in idiopathic scoliosis. The skeletal disorders that are caused by this hematologic dysfunction seem to be responsible for the spinal deformities and their evolution.