Degenerative scoliosis is a common condition in the elderly. Surgical treatment is controversial in many ways. The authors propose guidelines for surgical treatment, including decompression, posterior fixed fusion, anterior fusion, and osteotomy. These treatment recommendations are based on clinical and imaging analysis of the biomechanics of the deformity, as well as the mechanism of pain generation, sagittal balance, and other factors Scoliosis is broadly categorized as: nonstructural and structural. Nonstructural scoliosis includes: poor posture, hysteria, sciatica, inflammatory, compensatory, some of which become structural scoliosis. There is no vertebral rotation in this type of scoliosis. Structural scoliosis includes: congenital, neuromuscular, idiopathic, de novo, traumatic, and medical. Adult scoliosis (ADS) defined: cobb angle >10°. It is categorized as idiopathic or degenerative. The latter stems from degeneration of the spinal motor units, usually starting first with the intervertebral discs, and is followed by loss of compensatory capacity of the posterior structures, especially the small joints. Axial rotation leads to lateral slippage, as well as ligamentous laxity. Demographics Prevalence of scoliosis in adults 1-10%. 30% of older adults develop new deformities in the absence of previous spinal deformities. Diagnostic points: >40 years of age; exclude previous idiopathic scoliosis; lumbar scoliosis >10°; may be associated with compensatory thoracic curvature. Male-to-female ratio is about 1:1; mean age at presentation is about 70 years. Natural history Most cases start after 60 years of age and are associated with symptoms of spinal stenosis. Back pain and radicular pain may be the initial symptoms, which gradually worsen. Intermittent claudication symptoms are not relieved by forward body flexion. Progression is 1-6° per year. Decreased spinal bone mass may accelerate progression, but remains controversial. Age and gender do not affect progression. Factors that accelerate progression include: angle >30°, parietal rotation greater than II degrees, lateral slip >6 mm; iliac spine connection through lumbar 5 vertebrae. Evaluation Rule out history of idiopathic scoliosis; look for changes in height, gait, and clothing; location, duration, aggravating/slowing factors, and treatment of pain; axial or radicular pain. Most axial pain is associated with lateral displacement and sagittal imbalance, so correction of the deformity and reestablishment of sagittal balance may be necessary. For radicular pain note whether the pain is consistent with the concave position. Be careful to determine whether the lower extremity pain originates from central or lateral saphenous (entrance/intermediate/exit) stenosis of the spinal canal, with the latter requiring more extensive decompression, as well as fixation and fusion within the decompression. Pain may include low back pain and extremity pain, which determines the surgical path. Coronal and sagittal balance is observed visually, noting head and pelvic relationships. Record shoulder and pelvic tilt. Spinal flexibility was assessed by forward flexion and lateral bending maneuvers. Measure the presence of lower extremity inequalities and pelvic tilt. Those with lower extremity inequalities need to pad the short limbs and reassess curvature and flexibility. Neurologic examination includes: cranial nerves, muscle strength, reflexes, sensation, and gait. A vascular examination (Doppler ultrasound) is added if necessary. Palpate the sacroiliac joints and rotator areas to assess for hip and knee contractures. Assess cardiopulmonary function, bone quality, nutrition, and physical condition. Imaging Full-length frontal and lateral views of the spine.CT; MRI.Determine source of pain by small joint/nerve root block, discography. Measure x-ray data to help plan surgery. Re-emphasize the importance of sagittal balance. Emphasize the importance of the bony cords: suggest mechanical stability and determine surgical options. Treatment Conservative treatment No spinal stenosis, no radiating pain, no low back pain, curvature <30°, slippage <2 mm, and anterior bony encumbrance. Such patients have good coronal and sagittal balance. Treatment: low-intensity plyometric exercises; NSAIDs medications; anti-osteoporosis and bone loss treatments based on DEXA results; dural sac and selective nerve root injections of medications (with caution). Supportive devices have no role in reducing pain while producing a de-adaptive effect, and supportive devices do not stop the progression of scoliosis. Surgery In patients who have failed conservative treatment; kyphosis; anterior protrusion of the thoracolumbar segment; lateral slip of 6 mm or more; scoliosis >30-40°; progression of scoliosis >10°; progression of neurologic symptoms; progression of lateral slip >3 mm. Lenke-Silva’s 6-step surgical plan: I Decompression; II Decompression + short-segment posterior fixation and fusion; III Decompression + lumbar flexion fixation and fusion; IV Decompression + anterior and posterior fixation and fusion; V Extension to the thoracic spine fusion; V Expanded fixed fusion to the thoracic spine; VI Includes plane-specific osteotomies.