title: Comparison of two minimally invasive surgery strategies to treat adult spinal deformity.
abstract: OBJECTIVE
  Minimally invasive surgery (MIS) techniques are becoming a more common means of treating adult spinal deformity (ASD). The aim of this study was to compare the hybrid (HYB) surgical approach, involving minimally invasive lateral interbody fusion with open posterior instrumented fusion, to the circumferential MIS (cMIS) approach to treat ASD.
  
  
  METHODS
  The authors performed a retrospective, multicenter study utilizing data collected in 105 patients with ASD who were treated via MIS techniques. Criteria for inclusion were age older than 45 years, coronal Cobb angle greater than 20°, and a minimum of 1 year of follow-up. Patients were stratified into 2 groups: HYB (n = 62) and cMIS (n = 43).
  
  
  RESULTS
  The mean age was 60.7 years in the HYB group and 61.0 years in the cMIS group (p = 0.910). A mean of 3.6 interbody fusions were performed in the HYB group compared with a mean of 4.0 interbody fusions in the cMIS group (p = 0.086). Posterior fusion involved a mean of 6.9 levels in the HYB group and a mean of 5.1 levels in the cMIS group (p = 0.003). The mean follow-up was 31.3 months for the HYB group and 38.3 months for the cMIS group. The mean Oswestry Disability Index (ODI) score improved by 30.6 and 25.7, and the mean visual analog scale (VAS) scores for back/leg pain improved by 2.4/2.5 and 3.8/4.2 for the HYB and cMIS groups, respectively. There was no significant difference between groups with regard to ODI or VAS scores. For the HYB group, the lumbar coronal Cobb angle decreased by 13.5°, lumbar lordosis (LL) increased by 8.2°, sagittal vertical axis (SVA) decreased by 2.2 mm, and LL-pelvic incidence (LL-PI) mismatch decreased by 8.6°. For the cMIS group, the lumbar coronal Cobb angle decreased by 10.3°, LL improved by 3.0°, SVA increased by 2.1 mm, and LL-PI decreased by 2.2°. There were no significant differences in these radiographic parameters between groups. The complication rate, however, was higher in the HYB group (55%) than in the cMIS group (33%) (p = 0.024).
  
  
  CONCLUSIONS
  Both HYB and cMIS approaches resulted in clinical improvement, as evidenced by decreased ODI and VAS pain scores. While there was no significant difference in degree of radiographic correction between groups, the HYB group had greater absolute improvement in degree of lumbar coronal Cobb angle correction, increased LL, decreased SVA, and decreased LL-PI. The complication rate, however, was higher with the HYB approach than with the cMIS approach.
authors: Department of Neurosurgery, University of California, San Francisco, California;
authors: Paul
authors: P
authors: Park
authors: Michael Y
authors: MY
authors: Wang
authors: Virginie
authors: V
authors: Lafage
authors: Stacie
authors: S
authors: Nguyen
authors: John
authors: J
authors: Ziewacz
authors: David O
authors: DO
authors: Okonkwo
authors: Juan S
authors: JS
authors: Uribe
authors: Robert K
authors: RK
authors: Eastlack
authors: Neel
authors: N
authors: Anand
authors: Raqeeb
authors: R
authors: Haque
authors: Richard G
authors: RG
authors: Fessler
authors: Adam S
authors: AS
authors: Kanter
authors: Vedat
authors: V
authors: Deviren
authors: Frank
authors: F
authors: La Marca
authors: Justin S
authors: JS
authors: Smith
authors: Christopher I
authors: CI
authors: Shaffrey
authors: Gregory M
authors: GM
authors: Mundis
authors: Praveen V
authors: PV
authors: Mummaneni
mesh_terms: D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D064232:Visual Analog Scale
keywords: ASD = adult spinal deformity; BMI = body mass index; EBL = estimated blood loss; HYB = hybrid; LL = lumbar lordosis; LLIF = lateral transpsoas lumbar interbody fusion; MIS = minimally invasive surgery; ODI = Oswestry Disability Index; PI = pelvic incidence; PT = pelvic tilt; SVA = sagittal vertical axis; TLIF = transforaminal lumbar interbody fusion; VAS = visual analog scale; adult; cMIS = circumferential MIS; minimally invasive; scoliosis; spinal deformity; spinal fusion surgery; spinopelvic alignment