Review Question - QID 2196

Hemivertebra are best managed with resection and fusion in young patients prior to significant curve progression.

Congenital scoliosis is the failure of normal vertebral development during gestation. Hemivertebra are a form of congenital scoliosis and result from unilateral failure of formation in a region of the vertebral body with the absence of one pedicle. Fully segmented hemivertebrae are likely to cause progressive curvature given the presence of superior and inferior growth plates. Near-complete correction can be achieved by hemivertebra resection and fusion. Nonoperative management is rarely indicated.

Bradford et al. described their technique and outcomes of one-stage anterior and posterior hemivertebral resection and arthrodesis for congenital scoliosis. Seven children were included in their series with an average preoperative deformity of 47°. Postoperative deformities averaged 15° at a mean 45.6-month follow-up. No neurological deficits, infections, deaths, or pseudarthroses were identified. The authors conclude this technique allows correction of progressive deformity and is well tolerated.

Lazar et al. investigated simultaneous anterior and posterior hemivertebra excision in a series of 11 patients with a mean age of 18 months. Preoperative curves averaged 47° and postoperative curves averaged 14° at a mean follow-up of 28 months. One patient experienced transient leg weakness, otherwise, no other complications were identified. The authors conclude early intervention with this technique may provide better correction with less neurologic risk compared to late intervention.

Hedequist et al. reviewed congenital scoliosis and note hemivertebra excision is a safe and effective tool for treating isolated hemivertebra. Definable disks on radiograph signify the presence of vertebral growth plates. Therefore, the authors note a fully segmented hemivertebra with definable disks above and below have increased potential of causing curvature than an unsegmented hemivertebra. Furthermore, curve progression occurs more rapidly during the first 5 years of life and during the adolescent growth period.

Figure A is an anteroposterior radiograph of the lumbar spine demonstrating a hemivertebra.

Incorrect Answers
Answer 1: Bracing has not been shown to be an effective treatment for congenital scoliosis
Answer 3: A Cobb angle >45° is an indication for posterior spinal fusion in patients with idiopathic scoliosis
Answers 4 & 5: Hemi-vertebrectomy is indicated in skeletally immature patients prior to significant curve progression