General Session: MIS-4
Presented by: M. Wang - View Audio/Video Presentation (Members Only)
A. Theologis(1), S. Nguyen(2), G. Mundis(2,3), B. Akbarnia(2), R. Eastlack(3), M. Wang(4), P. Mummaneni(1), J. Uribe(5), D. Okonkwo(6), N. Anand(7), A. Kanter(6), P. Park(8), R. Fessler(9), V. Deviren(1), International Spine Study Group
(1) University of California, San Francisco, San Francisco, CA, United States
(2) San Diego Center for Spinal Disorders, San Diego, CA, United States
(3) Scripps Clinic, La Jolla, CA, United States
(4) University of Miami, Miami, FL, United States
(5) University of South Florida, Tampa, FL, United States
(6) University of Pittsburgh Medical Center, Pittsburgh, PA, United States
(7) Cedars Sinai, Los Angeles, CA, United States
(8) University of Michigan, Ann Arbor, MI, United States
(9) Rush University, Chicago, IL, United States
Hypothesis: Outcomes after circumferential fusion with LIFs in ASD are not influenced by placement method of posterior fixation (percutaneous vs. open). Design: Retrospective review of a multicenter ASD database.
Introduction: Data on effectiveness of ASD correction with percutaneous posterior fixation combined with LIFs are limited. We compared ASD patients who had circumferential fusions with LIFs and open and percutaneous posterior pedicle screw fixation.
Methods: Patients with ASD who underwent posterior instrumentation and LIFs via a MIS approach were sub-divided into 2 groups based on type of posterior pedicle screw fixation-open (hybrid) vs percutaneous (cMIS). Exclusion criteria: 3-column osteotomies, stand-alone LIF, and posterior-only instrumentation. Patient demographics, peri-operative data, and baseline and 2-year post-operative clinical outcomes and radiographic deformity parameters were analyzed.
Results: 426 patients met inclusion criteria, 155 with complete 2 year data were included (hybrid-65; cMIS-90; male 39; female 136; avg age 61 yrs). Both groups had significant improvements in Cobb angles, lumbar lordosis, lumbopelvic mismatch, ODI, and VAS back and leg pain (p< 0.05). For all the following, cMIS had significantly (p< 0.05) less EBL (536vs1199cc), shorter OR times (440vs627mins), smaller pre-op Cobb angles (37vs440), more anterior levels fused (3.7vs3.2), fewer posterior levels fused (5.1vs8.4), fewer minor (16vs32%), and overall complications (33vs54%), and lower ODI scores (28vs37) 2-years post-op compared to hybrids. Age, gender, BMI, pre-operative ODI, VAS back and leg pain, and all other pre- and post-op x-ray parameters were similar between groups.
Conclusions: Circumferential fusion with MIS LIFs and posterior instrumentation is an effective technique for pain relief and radiographic deformity correction in well-balanced, moderate, symptomatic thoracolumbar deformities. Compared to open posterior instrumentation, percutaneous pedicle screws result in fewer complications, less blood loss, shorter operative times, and less disability 2-years post-operatively.