Surgical management of flatback syndrome in adult spinal deformity: a collection of illustrative cases

Background: Flatback Syndrome (FBS) is a common type of adult spinal deformity (ASD) characterized clinical by loss of lumbar lordosis. This condition develops due to numerous reasons including complications from previous thoracolumbar instrumentation. Patients with FBS typically fail conservative measures and require surgical intervention. The goal of surgical management is normalization of radiographic parameters including lumbar lordosis, pelvic tilt, and age-adjusted sagittal vertical axis. Variations of osteotomies and interbody fusions have been used to treat FBS with variable outcomes. The objectives of this paper are to describe observations and lessons learned in the complex treatment of Flatback Syndrome through illustrating 5 unique cases. Observations: 5 illustrative cases of spinal deformity surgery for the treatment of flatback syndrome were presented and highlight surgical techniques and strategies for deformity correction including: various osteotomies, interbody placement, multi-rod constructs and anterior column reconstruction. Lessons: Restoration of sagittal balance postoperatively is critical in reducing the risks of flatback syndrome and proximal junctional kyphosis. Patient-specific risk factors and preoperative radiographic parameters should be used to tailor individualized treatment plans prior to surgical management of flatback syndrome. Improved awareness of the number of technical options available for patients with ASD is critical to selecting a patient-specific plan.