General Session: Adult Spinal Deformity

Presented by: P. Park - View Audio/Video Presentation (Members Only)


P. Park(1), M. Wang(2), S. Nguyen(3), G. Mundis(3,4), F. La Marca(1), J. Uribe(5), N. Anand(6), D. Okonkwo(7), A. Kanter(7), R. Fessler(8), R. Eastlack(4), D. Chou(9), V. Deviren(9), P. Nunley(10), C. Shaffrey(11), P. Mummaneni(9), International Spine Study Group

(1) University of Michigan, Ann Arbor, MI, United States
(2) University of Miami, Miami, FL, United States
(3) San Diego Center for Spinal Disorders, San Diego, CA, United States
(4) Scripps Clinic, La Jolla, CA, United States
(5) University of South Florida, Tampa, FL, United States
(6) Cedars Sinai, Los Angeles, CA, United States
(7) University of Pittsburgh Medical Center, Pittsburgh, PA, United States
(8) Rush University, Chicago, IL, United States
(9) University of California, San Francisco, San Francisco, CA, United States
(10) Spine Institute of Louisiana, Shreveport, LA, United States
(11) University of Virginia, Charlottesville, VA, United States


Objective: Obesity has been associated with increased complications and potentially worse outcomes after spinal surgery. Minimally invasive approaches are increasingly applied to patients with adult spinal deformity (ASD). The primary purpose of this study is to evaluate the impact of obesity on complications and outcomes in patients with ASD who underwent minimally invasive surgery (MIS).

Methods: A multicenter database of minimally invasively treated patients with ASD was queried. The database included patients treated circumferentially by MIS techniques (cMIS) and those treated with a combination of minimally invasive and open techniques (HYB). Inclusion criteria for the study consisted of cMIS patients who had 3 or more spinal levels treated. Of the 190 patients who comprised the database, 77 fit the inclusion criteria. The patients were then divided into those with BMI < 30 (non-obese, N=59) and those with BMI ≥ 30 (obese, N=18).

Results: Mean ages in the non-obese and obese group were 60.4 and 66.2 years, respectively (p=0.117). Mean BMI was 24.6 in the non-obese group and 35.0 in the obese group (p< 0.001). On average there were 3.8 interbody fusions and 5.8 levels treated posteriorly in the non-obese group compared to 4.7 interbody fusions and 5.9 level treated posteriorly in the obese group (p=0.065, p=0.502). Mean follow-up was 34.4 months in the non-obese and 35.3 in obese patients (p=0.976). Baseline radiographic parameters were similar between groups. Post-operatively, SVA and LL-PI mismatch averaged 83.9 mm and 17.9° in the obese compared to 20.4 mm and 9.9° in the non-obese (p=0.002, p=0.028). Both groups had significant improvement in ODI and there were no significant differences in post-operative ODI between groups (p=0.09). Similarly, both groups had decreased VAS back and leg pain scores and there were no significant differences between groups postoperatively (p=0.261, p=0.577). There were 20 (33.9%) non-obese patients who had adverse events compared to 7 (38.9%) obese patients who had complications (p=0.452). When subdivided into major and minor complications, there still was no significant difference between groups.

Conclusion: Minimally invasive approaches are increasingly applied to patients with ASD. The results of this study suggest that obesity does not negatively impact the complication rate or clinical outcomes in patients with ASD treated by minimally invasive approaches. There may be a difference, however, in radiographic outcomes particularly in the maintenance or improvement of sagittal alignment in the obese, which in the long-term may affect clinical outcomes.