COPYRIGHT © 2006 BY THE JOURNAL OF BONE AND JOINT SURGERY, INCORPORATED  Lumbar Hemivertebra Resection BY GÉRARD BOLLINI, MD, PHD, PIERRE-LOUIS DOCQUIER, MD, ELKE VIEHWEGER, MD, FRANCK LAUNAY , MD, AND JEAN-LUC JOUVE, MD, PHD Investigation performed at Hôpital Timone Enfants, Marseille, France Background: A single lumbar hemivertebra can be expected to cause progressive scoliosis. The aim of this study was to evaluate the results of a lumbar hemivertebra resection and short-segment fusion through a combined poste- rior and anterior approach. Methods: From 1987 to 2002, a consecutive series of twenty-one patients with congenital scoliosis or kyphoscolio- sis due to a lumbar hemivertebra were managed by resection of the hemivertebra through a combined posterior and anterior approach and with the use of a short anterior and posterior convex-side fusion. Results: The mean age at the time of surgery was 3.3 years (range, twelve months to 10.2 years). The mean follow- up period was 8.6 years. There was a mean improvement of 71.4% in the segmental scoliosis curve from a mean an- gle of 32.9° before surgery to 9.4° at the time of the latest follow-up assessment, and a mean improvement of 63.9% in the global scoliosis curve from 34.1° to 12.3°. The mean final lordosis was within normal values. Conclusions: Excision of a lumbar hemivertebra is safe and provides stable correction when combined with a short- segment fusion. Surgery should be performed as early as possible to avert the development of severe local deformi- ties and prevent secondary structural deformities that would require a more extensive fusion later. Level of Evidence: Therapeutic Level IV . See Instructions to Authors for a complete description of levels of evidence. he natural history of congenital scoliosis and kyphosis has been well documented 1-3 . The degree of scoliosis produced by a hemivertebra depends on the type, site, and number of hemivertebrae and the patient’s age. Thora- columbar and lumbosacral junctions are transitional areas be- tween the mobile lumbar spine and the less mobile thoracic spine or sacrum. Hemivertebrae located in these two transi- tional areas lead to trunk shift. In the thoracolumbar and lum- bar spine, progressive kyphosis may also occur. A lumbosacral hemivertebra, however, usually does not lead to progressive kyphosis. A single lumbar hemivertebra (between L2 and L4) can be expected to cause progression of scoliosis at a rate of 1.7° per year if it is fully segmented and 1° per year if it is partially segmented 4 . When scoliosis progression of ≥5° is observed on serial radiographs of our patients, operative intervention is advised. The aim of this study was to evaluate the results of lum- bar hemivertebra resection and short-segment fusion through a combined posterior and anterior approach in a consecutive series of twenty-one patients. Materials and Methods Series of Patients (Table I) rom March 1987 to July 2002, twenty-one lumbar hemi- vertebrae were excised in twenty-one consecutive patients (eight girls and thirteen boys). These hemivertebrae were lo- cated at the L2-L3 level in nine patients, the L3-L4 level in four patients, and the L4-L5 level in eight patients. The mean age of the patients at the time of surgery was 3.3 years (range, twelve months to 10.2 years). All deformities were congenital scolio- sis or kyphoscoliosis. All but two patients had evidence of curve progression of ≥5° between two successive radiographs, and all had a fully segmented or a semi-segmented hemiverte- bra. The two patients who did not demonstrate progression had a fully segmented hemivertebra and had 34° and 37° of scoliosis at the ages of twelve and fifteen months, respectively. Anatomical Data The data on the congenital spine abnormalities and associated conditions are summarized in Table I. Each complete vertebra was identified as either thoracic or lumbar. An asymmetrical transitional vertebra with a costotransverse joint and a con- tralateral lumbar-type transverse process was considered to be thoracic, but the absence of rib was noted. Each hemivertebra was not numbered by level but according to the two adjacent complete vertebrae 5 . For example, an L2-L3 hemivertebra cor- responds to a hemivertebra located between the second and the third lumbar-type vertebrae. There were five right-sided and sixteen left-sided hemivertebrae. Eleven were fully seg- mented and ten were semi-segmented. Sixteen patients (76%) had other spine abnormalities (Table I). Preoperative Evaluation Preoperative radiographic imaging included standing poster- oanterior and lateral view radiographs of the full spine. All but T F