A Prospective Propensity Matched Cohort Analysis of Minimally Invasive (MIS), Hybrid (HYB), and Open Spine Surgery (OPEN) for the Treatment of Adult Spinal Deformity (ASD)

Presented at SMISS Annual Forum 2013
By Gregory Mundis MD
With Behrooz Akbarnia 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, Paul Park MD, Christopher Shaffrey MD, Frank Schwab MD, Shay Bess MD, International Group ,

Disclosures: Gregory Mundis MD A; ISSGF, Nuvasive. B; K2M, Medicrea, Misonix, Nuvasive. C; K2M, Nuvasive. F; Nuvasive. Behrooz Akbarnia MD A; Depuy Synthes Spine. B; NuVasive, K2M, Ellipse, Kspine. D; Alphatec Spine, NuVasive, Ellipse, Kspine, Nocimed., 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., Paul Park MD B; Biomet, Globus, Medtronic, Nuvasive. F; Globus, Christopher Shaffrey MD None, Frank Schwab MD A; NIH, DePuy Synthes Spine, Medtronic, AO, OREF. B; DePuy Synthes Spine, Medtronic, K2M. C; DePuy Synthes Spine, Medtronic. D; Nemaris Inc.. F; Medtronic., Shay Bess MD A; DePuy Synthes Spine, Medtronic. B; DePuy Synthes Spine, Medtronic, Alphatec, Allosource, K2M. F; Pioneer., International Group A; Biomet, Depuy, Innovasis, K2M, Medtronic, Nuvasive, Stryker.,

Introduction: Operative intervention for ASD is well established. MIS techniques have been increasingly applied to treat ASD. MIS, OPEN, and HYB techniques were compared in an ASD patient population through propensity matching.

Methods: 280 pts in 2 prospective databases (MIS n=85; OPEN n=195) were retrospectively reviewed, divided in 3 separate approaches OPEN, MIS, and HYB and propensity matched for age, ODI, SVA and major Cobb (p>0.05). Inclusion criteria: age >45, Cobb >20°, min 1 yr follow up. Groups: 1)MIS- standalone lateral transpsoas (LIF), LIF with MIS posterior pedicle screws (PPS), and MIS TLIF (n=31). 2)HYB- LIF with open PPS(n=31); 3)OPEN- Open PPS +/- interbody (n= 31). Group 1 compared with Anova and Intra-group with paired t-test.

Results: At 1yr there was no difference in major Cobb (MC), PI-LL, PT or SVA. OPEN had more LL (52.5) at 1yr than MIS(40.5; p<0.001) and HYB (44.4; p=0.023). There was no difference between group at preop or 1yr in Schwab-SRS classification. All groups reached significant decrease in ODI at 1yr. Within each group there was significant improvement in MC, LL, and PI-LL. MIS had significantly less EBL and transfusion (563cc; 32.3%) than HYB or OPEN (1802cc, 58.1% and 1974cc, 83.9%; p<0.003). OR time was longer with HYB (735 min) than MIS and OPEN (461 and 407 min; p<0.001). OPEN was associated with more levels fused (9.3) than MIS (4.8; p<0.001) and HYB (7; p=0.03). Open surgery was extended to the pelvis 80.6% vs. 22.6% and 67.7% for MIS and HYB (p<0.001). Major complications occurred in 12% of MIS, 33.3% HYB, and 44.8% OPEN (p=0.032).

Conclusion: This is the first study to evaluate different surgical techniques to treat patients with statistically similar disability and spine deformity. All groups resulted in significant improvement in ODI. MIS was associated with less EBL, transfusion, fusion levels, and a favorable complication profile compared to HYB and OPEN. Our data supports the role of MIS for ASD.