Degenerative Lumbar Scoliosis Rod J. Oskouian Jr, MD, Christopher I. Shaffrey, MD * Department of Neurological Surgery, University of Virginia, PO Box 800212, Charlottesville, VA 22902, USA The management of spinal deformity in the adult has gone through a significant evolution during the past decade. Even with advances in spinal instrumentation and technique, the goal of any deformity surgery remains to achieve a stable well-balanced spine centered over the pelvis while fusing as few motion segments as possible. A balanced painless spine is created by a close interplay of the patient’s spinal anatomy, the bio- mechanical properties of the spine and its sur- rounding structures, and the corrective capabilities of surgical techniques and instrumentation. Newer surgical techniques as well as advances in spinal instrumentation have markedly im- proved the ability to correct spinal deformity, particularly rigid deformity, and frequently in- volve the use of transpedicular instrumentation with or without an anterior release or osteotomy procedure. As the complexity of the surgical procedure increases, the risk of complications markedly increases, particularly in older adult patients. To balance surgical benefits and risks, a detailed analysis of the coronal and sagittal balance, relative flexibility of all curves, presence of adjacent segment disease, alignment of the thoracolumbar and lumbosacral junctions, and determination of whether the deformity is fixed or fused is required. The amount of clinical and radiographic analysis exceeds what is typically performed for other degenerative disorders of the lumbar spine but is fundamental to treating deformity effectively and avoiding some of the pitfalls and complications. In this article, we review some of the salient points of neglected idiopathic and degenerative lumbar scoliosis evaluation and operative man- agement. This review includes the classification of adult scoliosis by defining the natural history, incidence, rate of progression, and clinical pre- sentation. The preoperative clinical evaluation is described, including determination of the flexibil- ity of scoliosis as well as surgical treatment options, including instrumentation levels, use of lumbosacral and spinopelvic fixation, length of fusion, methods to reduce pseudoarthrosis, and biologic therapies to increase fusion. Finally, a review of common complications and a discus- sion of the results of surgery, complication avoid- ance, and future directions in spinal fusion are provided. Classification of scoliosis Practicing neurosurgeons should have a basic understanding of the epidemiology, natural his- tory, progression, therapy, and current classifica- tions of a particular deformity so that they may manage spinal deformity in patients [1–3]. Stan- dard terminology has been established in a glossary by the Scoliosis Research Society (SRS), which is available on the SRS web site [4] and serves as a common language for defining spinal deformity. In a normally balanced spine, the plumb line should pass through the center of the sacrum on an anteroposterior (AP) radiograph and should pass from the C7 vertebral body through the posterior aspect of the L5/S1 interspace on the lateral radiograph. Scoliosis is defined as a spinal deformity with a Cobb angle greater than 10  in the coronal plane (Fig. 1) [5–8]. Cobb angles are measured on these radiographs by using a goniom- eter in the AP and lateral orientations. A Cobb angle is measured by taking the angles of lines that are perpendicular to the end plates of the * Corresponding author. E-mail address: cis8z@virginia.edu (C.I. Shaffrey). 1042-3680/06/$ - see front matter Ó 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.nec.2006.05.002 neurosurgery.theclinics.com Neurosurg Clin N Am 17 (2006) 299–315