Neurological complications in adult spinal deformity surgery

The number of surgeries performed for adult spinal deformity (ASD) has been increasing due to an aging population, longer life expectancy, and studies supporting an improvement in health-related quality of life scores after operative intervention. However, medical and surgical complication rates remain high, and neurological complications such as spinal cord injury and motor deficits can be especially debilitating to patients. Several independent factors potentially influence the likelihood of neurological complications including surgical approach (anterior, lateral, or posterior), use of osteotomies, thoracic hyperkyphosis, spinal region, patient characteristics, and revision surgery status. The majority of ASD surgeries are performed by a posterior approach to the thoracic and/or lumbar spine, but anterior and lateral approaches are commonly performed and are associated with unique neural complications such as femoral nerve palsy and lumbar plexus injuries. Spinal morphology, such as that of hyperkyphosis, has been reported to be a risk factor for complications in addition to three-column osteotomies, which are often utilized to correct large deformities. Additionally, revision surgeries are common in ASD and these patients are at an increased risk of procedure-related complications and nervous system injury. Patient selection, surgical technique, and use of intraoperative neuromonitoring may reduce the incidence of complications and optimize outcomes.