Comparison of 3 Minimally Invasive Surgery (MIS) Strategies to Treat Adult Spinal Deformity (ASD)

Presented at SMISS Annual Forum 2013
By Paul Park MD
With Gregory Mundis MD, Juan Uribe MD, FACS, Neel Anand MD, Vedat Deviren MD, Robert Eastlack MD, Richard Fessler MD, PhD, Virginie LaFage PhD, Michael Wang MD, Praveen Mummaneni MD, David O Okonkwo , Adam Kanter MD, Frank LaMarca MD, Christopher Shaffrey MD, International Group , John Ziewacz MD,

Disclosures: Paul Park MD B; Biomet, Globus, Medtronic, Nuvasive. F; Globus Gregory Mundis MD A; ISSGF, Nuvasive. B; K2M, Medicrea, Misonix, Nuvasive. C; K2M, Nuvasive. F; Nuvasive., Juan Uribe MD, FACS A; Nuvasive. B; Nuvasive. C; Nuvasive. D; Nuvasive. F; Nuvasive, Neel Anand MD None, Vedat Deviren MD A; AOSpine, Globus, Nuvasive. B; Nuvasive. F; Nuvasive., Robert Eastlack MD None, Richard Fessler MD, PhD None, Virginie LaFage PhD A; SRS, DePuy Synthes Spine. B; Medtronic. C; K2M, Medtronic, DePuy Synthes Spine. D; Nemaris Inc., Michael Wang MD None, Praveen Mummaneni MD B; Globus, David O Okonkwo None, Adam Kanter MD None, Frank LaMarca MD A; NIH, NREF, Globus, DePuy Synthes Spine. B; Biomet, Lanx, Globus. F; Globus, Stryker., Christopher Shaffrey MD None, International Group A; Biomet, Depuy, Innovasis, K2M, Medtronic, Nuvasive, Stryker., John Ziewacz MD None,

Introduction: MIS techniques are becoming a more common means of treating ASD. We aim to compare 3 different approaches: 1) Hybrid(HYB): lateral interbody fusion(LLIF) with open posterior instrumented fusion; 2) Stand-alone MIS(saMIS): LLIF only and 3) Circumferential MIS(cMIS) and their ability to treat ASD.

Methods: Retrospective, multicenter study of prospectively-collected data of 99 ASD pts treated with MIS techniques. Inclusion criteria: age>45; coronal cobb>20°; minimum 1-year follow-up. Patients were stratified into 3 groups: HYB(n=51), saMIS(n=8), and cMIS(n=40).

Results: Mean age was 63.9 years (range=46-84). A mean of 6.7 segments were treated (range=3-16) and mean follow-up was 26 months (range=12-58). For all patients, ODI improved from 44.7 to 28.1 (p<0.001) and mean preop and postop xray parameters (min 1yr) were lumbar coronal Cobb (CC) (38.1° to 15.4°), lumbar lordosis(LL) (33.3° to 44.4°), SVA (48.8 mm to 31.1 mm), and LL-pelvic incidence mismatch (LL-PI) (22.0° to 9.8°) (all p<0.001). For HYB patients, pre vs. post x-ray parameters were CC (43.8° to 16.7°), LL (32.5° to 48.1°), SVA (67.5 mm to 32.2 mm), and LL-PI (22.5° to 3.3°) (all p<0.001). Mean ODI improved from 47.3 to 32.5 (p<0.001). For saMIS patients, pre vs. post x-ray parameters were CC (37.3° to 34.7°), LL (34.0° to 39.7°), SVA (31.0 mm to 31.2 mm), and LL-PI (23.6° to 16.2°) (all p>0.05). Mean ODI improved from 44.8 to 32.0 (p=0.037). For cMIS patients, pre vs. post x-ray parameters were CC (31.6° to 10.4°), LL (34.3° to 40.3°), and LL-PI (21.3° to 16.0°) (all p<0.008). There was no significant change in SVA (29.0 mm to 29.7 mm). Mean ODI improved from 41.6 to 22.5 (p<0.001).

Conclusion: Of the three MI approaches, the HYB approach best restored spinopelvic alignment. The saMIS approach was least likely to re-establish spinopelvic parameters. All three approaches resulted in clinical improvement as evidence by decreased ODI and VAS pain. The change in ODI and VAS pain was least significant in the saMIS cohort possibly reflecting the poor radiographic improvement.