General Session: MIS-4
Presented by: J. Millard - View Audio/Video Presentation (Members Only)
N. Anand(1), J. Millard(1), R. Cohen(1), J. Cohen(1), B. Khandehroo(1), E. Baron(1), S. Kahwaty(1)
(1) Cedars-Sinai Medical Center, Spine Center, Los Angeles, CA, United States
Introduction: Predictors of outcome following CMIS spinal surgery for adult spinal deformity (ASD) have not been well studied. Identifying both clinical and radiological predictors of the most favorable and unfavorable ASD surgical outcomes may provide a useful tool. We conduct this study to assess significant predictors associated with the 10 best and 10 worst outcomes of CMIS correction of ASD surgery.
Methods: This is a single center study from a prospective database of all patients who underwent CMIS correction for ASD (Cobb angle > 20 degrees or SVA > 50 mm or PI/LL mismatch > 10). 133 patients who had CMIS surgery at 3 or more levels and at least one year follow-up were identified. The 10 patients with the best ODI were compared to the 10 patients with the worst ODI. Patient factors, radiological markers and clinical outcomes were studied.
Results: The 10 best patients had average preoperative and postoperative ODI of 30.6 (range 14-55.6, SD 11.8) and 0.8 (range 0-4, SD 1.4), VAS of 4.8(2-8) and 0.2(0-2), COBB angles of 29 degrees (15-56) and 11.2 degrees (0-25), and SVA of 57.3mm (20-139) and 22.3mm (0-57.6) respectively. The 10 worst patients had average preoperative and postoperative ODI of 51.7 (range 22-82, SD 17.1) and 59.5 (range 48-77.8, SD 10.3), VAS of 7.3(4-10) and 4.7(1-7), COBB angles of 26.9 degrees (15-39) and 11.7 degrees (1.2-21), and SVA of 91.8 mm (28-140) and 35.1 mm (8.8-84.8) respectively. The 10 best patients had significantly lower preoperative ODI (P< .05) and VAS (P< .05), less complications (P< .05) and lower incidence of postoperative pseudoarthrosis (P< .05). 80% of the patients in the worst outcome group were operated on before 2011. Patient factors (age, sex, depression, diabetes, BMI, smoking) and baseline deformity (COBB angle, AVT, Coronal Balance, SVA, PI-LL mismatch) were not statistically significant.
Conclusion: Our study would suggest that pre-op ODI and VAS is a significant factor in patients final outcome with CMIS techniques and judicious selection is critical. Our study also demonstrates that the worst outcomes are directly associated with postoperative complications, especially pseudoarthrosis. Moreover, 80% of poor cases occurred before 2011, possibly an indication of the learning curve and increasing experience in CMIS correction has improved the outcomes and reduced the complications.