Pathogenesis, presentation, and treatment of lumbar spinal stenosis associated with coronal or sagittal spinal deformities.

Sagittal- or coronal-plane deformity considerably complicates the diagnosis and treatment of lumbar spinal stenosis. Although decompressive laminectomy remains the standard operative treatment for uncomplicated lumbar spinal stenosis, the management of stenosis with concurrent deformity may require osteotomy, laminectomy, and spinal fusion with or without instrumentation. Broadly stated, the surgery-related goals in complex stenosis are neural decompression and a well-balanced sagittal and coronal fusion. Deformities that may present with concurrent stenosis are scoliosis, spondylolisthesis, and flatback deformity. The presentation and management of lumbar spinal stenosis associated with concurrent coronal or sagittal deformities depends on the type and extent of deformity as well as its impact on neural compression. Generally, clinical outcomes in complex stenosis are optimized by decompression combined with spinal fusion. The need for instrumentation is clear in cases of significant scoliosis or flatback deformity but is controversial in spondylolisthesis. With appropriate selection of technique for deformity correction, a surgeon may profoundly improve pain, quality of life, and functional capacity. The decision to undertake surgery entails weighing risk factors such as age, comorbidities, and preoperative functional status against potential benefits of improved neurological function, decreased pain, and reduced risk of disease progression. The purpose of this paper is to review the pathogenesis, presentation, and treatment of lumbar spinal stenosis complicated by scoliosis, spondylolisthesis, or flatback deformity. Specific attention is paid to surgery-related goals, decision making, techniques, and outcomes.