When not to Operate in Spinal Deformity: Identifying Subsets of Patients With Simultaneous Clinical Deterioration, Major Complications, and Reoperation

Study Design: Retrospective review of a prospectively enrolled adult spinal deformity (ASD) database. Objective: To investigate what patient factors elevate the risk of sub-optimal outcomes after deformity correction. Background: Currently, it is unknown what factors predict a poor outcome after adult spinal deformity surgery, which may require increased preoperative consideration and counseling. Materials and Methods: Patients >18 yrs undergoing surgery for ASD(scoliosis≥20°, SVA≥5 cm, PT≥25°, or TK≥60°). An unsatisfactory outcome was defined by the following categories met at two years: (1) clinical: deteriorating in ODI at two years follow-up (2) complications/reoperation: having a reoperation and major complication were deemed high risk for poor outcomes postoperatively (HR). Multivariate analyses assessed predictive factors of HR patients in adult spinal deformity patients. Results: In all, 633 adult spinal deformity (59.9 yrs, 79% F, 27.7 kg/m^2, CCI: 1.74) were included. Baseline severe Schwab modifier incidence (++): 39.2% pelvic incidence and lumbar lordosis, 28.8% sagittal vertical axis, 28.9% PT. Overall, 15.5% of patients deteriorated in ODI by two years, while 7.6% underwent reoperation and had a major complication. This categorized 11 (1.7%) as HR. HR were more comorbid in terms of arthritis (73%), heart disease (36%), and kidney disease (18%), P<0.001. Surgically, HR had greater EBL (4431ccs) and underwent more osteotomies (91%), specifically Ponte(36%) and Three Column Osteotomies(55%), which occurred more at L2(91%). HR underwent more PLIFs (45%) and had more blood transfusion units (2641ccs), all P<0.050. The multivariate regression determined a combination of a baseline Distress and Risk Assessment Method score in the 75th percentile, having arthritis and kidney disease, a baseline right lower extremity motor score ≤3, cSVA >65 mm, C2 slope >30.2°, CTPA >5.5° for an R² value of 0.535 (P<0.001). Conclusions: When addressing adult spine deformities, poor outcomes tend to occur in severely comorbid patients with major baseline psychological distress scores, poor neurologic function, and concomitant cervical malalignment.