Application of a lumbar brace for thoracic and double thoracic lumbar scoliosis: a comparative study.

A pilot study was performed to determine if thoracic and double thoracic lumbar scolioses can successfully be treated by applying a lumbar brace. In some of the patients application of a thoracic brace yielded insufficient correction of the lumbar curve. As the response of a curve to application of a brace is said to be the best guideline for prediction of the results of brace treatment, it was thought important to focus more attention on the behaviour of the lumbar curve. It was assumed that a lumbar brace would result in a better fit and might lead to better correction of the lumbar curve. In total 21 patients were treated according to the above-described method. Three patients were omitted from the study because of incomplete radiographic data. Thus, 18 patients treated with a thoracic brace, who showed insufficient correction of the lumbar curve, were subsequently treated with a lumbar brace. Radiographs taken in the thoracic brace patients showed a mean decrease of the thoracic curve of 9 degrees (27%) and a mean decrease of the lumbar curve of 5 degrees (16%). In the lumbar brace group the mean decrease of the thoracic curve was 7 degrees (21%) and the mean decrease of the lumbar curve was 12 degrees (38%). Brace treatment was successful (<6 degrees progression of the major curve) in 13 patients (70%). In this selection of patients with thoracic and double thoracic lumbar scoliosis a lumbar brace clearly led to a better initial correction of the lumbar curve; follow-up results seem to be comparable to those in literature.

Changes in curve pattern after brace treatment for idiopathic scoliosis.

We studied whether thoracic Boston brace treatment changes the King type of scoliotic curves in a group of 50 patients with adolescent idiopathic scoliosis. Bending radiographs showed more flexibility of the lumbar curves than that of the thoracic curves. However, after initial application of the brace, the mean lumbar correction in degrees was less than the mean thoracic correction. After brace treatment we found a slight statistically significant increase in the mean lumbar curve, but no significant change in the mean thoracic curve. In 7 of our patients, we found a change in the King classification which seemed to be related to insufficient lumbar correction at the start of brace treatment. When classifying idiopathic scoliosis, one should bear in mind that the result may be temporary because scoliosis is a dynamic process. A change in curve type can occur during brace treatment.

No relationship exists between the correction of the thoracic and the lumbar curves after selective thoracic fusion for adolescent idiopathic scoliosis King type II.

In this study we focus on idiopathic scoliosis with a primary thoracic curve and a secondary lumbar curve. We were interested in how the lumbar curve corrects following selective thoracic fusion and whether one can explain or predict the behaviour of the lumbar curve. In the literature it is said that, if the lower level of fusion is properly selected, the lumbar curve spontaneously corrects to balance the thoracic curve after selective thoracic fusion. Most authors have assumed a mechanism whereby improvement of the lumbar curve occurs through counterbalancing the surgical correction of the thoracic curve. The correction of the lumbar curve is said to echo the correction obtained for the thoracic curve. Because of these hypotheses, we postulate there should be a correlation between the correction of the lumbar and the thoracic curves of a scoliosis. To validate this hypothesis, we performed a retrospective study on 27 patients with King type II adolescent idiopathic scoliosis treated by selective thoracic fusion. The mean preoperative Cobb angles were 54 degrees for the thoracic curve and 34 degrees for the lumbar curve. Postoperatively they were 31 degrees and 22 degrees respectively. Using Pearson correlation analysis, we found no significant correlation between the relative corrections of the individual thoracic and lumbar curves. Moreover, there was a decrease in the correlation between the thoracic and lumbar curve after operation (preoperative R=0.787, postoperative R=0.364). These results show that the correction of the lumbar curve is not a reflection of the thoracic correction. The exact mechanism by which the lumbar spine corrects remains to be elucidated.