Degenerative Lumbar Scoliosis: a Multi-center Study

Degenerative lumbar scoliosis is a spinal deformity that typically develops among adults over 50 years old. Characterized with low back pain, leg pain and abnormal body posture to various degrees, patients are mostly offered conservative treatment in early stages, and then resort to surgical treatment when medication fail to achieve alleviation. The surgical procedures to treat degenerative lumbar scoliosis include spinal decompression, fusion, and instrumentation, or a combination of several of the above. Osteotomy is generally required when it comes to rigid deformity. However, surgical treatment strategies are complicated by factors comprising osteoporosis, paraspinal muscle degeneration, common yet severe postoperative complications resulting from specific surgical methods, and chronic metabolic diseases and so on. A detailed and individualized surgical planning has been under debate and development continuously. Also, most previous classifications and researches are centered on the population of the white. Representative data of the yellow people, especially Chinese people, from multicentric studies are scarce.

Patients undergone surgeries for degenerative lumbar scoliosis in 8 hospitals in China between 2010 and 2020 are retrospectively selected and enrolled. Patients' clinical data from pre-operation, post-operation and the last follow-up are revaluated. General patient data are collected after informed consent, such as age, gender, height, weight, body mass index and bone mineral density measured in T-scores, together with surgical data including operation duration, blood loss, physical status grades based on the American Society of Anesthesiologists Classification, surgical approaches, upper instrumented vertebra, lowest instrumented vertebra, osteotomy grades based on Schwab Classification, osteotomy levels, lumbosacral curve levelling approaches, cemented vertebrae, and perioperative complications. Radiographic parameters of the spine are also measured from X-rays, including the upper end vertebra of the major curve, apical vertebral translation, Cobb angles of the major and fractional curves, coronal balance distance, coronal classification of the deformity based on the Drum Tower Classification, L4 and L5 tilt on the coronal plane, lumbar tilt, thoracic kyphosis, lumbar lordosis, thoracolumbar kyphosis, sagittal vertical axis, T1 pelvic angle, pelvic tilt, sacral slope, L4-S1 lordotic angle, and proximal junctional angle. Clinical outcomes assessed with Japanese Orthopaedic Association score, Oswestry Disability Index and visual analogue scale of leg/back pain are also gathered. Correlation between demographic, surgical, and radiographic parameters and clinical outcomes are statistically explored, in order to find indexes that help group and match patients with their optimum surgical strategies.