title: Increasing lumbar lordosis of adult spinal deformity patients via intraoperative prone positioning.
abstract: METHODS
  A retrospective evaluation.
  
  
  OBJECTIVE
  To evaluate the change in lumbar lordosis in spinal deformity patients who underwent an instrumented posterior spinal fusion on the Orthopedic Systems Inc. (OSI) "Jackson" frame.
  
  
  BACKGROUND
  Intraoperative prone positioning with hip extension may posturally increase lumbar lordosis during adult spinal deformity reconstructive surgery, as has been shown in adult lumbar degenerative surgery.
  
  
  METHODS
  Radiographs of 44 operative spinal deformity patients (43 females/1 male; mean age, 57.4 years) were analyzed. Diagnoses included idiopathic scoliosis (29), degenerative lumbar scoliosis (9), and other (6). Total lumbar lordosis (T12-S1), segmental disc angles, and C7 plumbline were measured on preoperative upright and supine, intraoperative prone, and postoperative upright lateral radiographs. All patients were positioned intraoperatively with hip extension on the OSI frame.
  
  
  RESULTS
  Average preoperative upright and supine, intraoperative prone, and postoperative upright lumbar lordosis (T12-SAC) measurements were -38.1 degrees, -46.0 degrees, -46.2 degrees, and -51.8 degrees, respectively (P < 0.05 for preoperative upright to all other comparisons). Two groups were noted: those with increased lumbar lordosis (>5 degrees) during intraoperative prone positioning (n = 25, increased lordosis group) as compared to the preoperative measurement versus those with minimal to no change in lordosis (< or =5 degrees) during intraoperative prone positioning (n = 19, unchanged lordosis group). The corresponding lumbar lordosis measurements for the increased lordosis group were -25.9 degrees, -40.0 degrees, -43.1 degrees, and -48.9 degrees (P < 0.05 for preoperative upright to all other comparisons). The corresponding lumbar lordosis measurements for the unchanged lordosis group were -54.2 degrees, -53.8 degrees, -50.3 degrees, and -55.7 degrees (no significant differences). Preoperative upright lumbar lordosis in the unchanged lordosis group was substantially higher than increased lumbar lordosis group (P < 0.05).
  
  
  CONCLUSIONS
  Adult spinal deformity patients with preoperative hypolordosis who were positioned prone during reconstructive surgery had an enhanced lumbar lordosis via positioning alone compared with theirpreoperative upright radiographs. Conversely, those with substantial preoperative lordosis remained unchanged with intraoperative prone positioning. This knowledge will help in the surgical planning of adult spinal deformity reconstructive surgery to optimize sagittal alignment and balance.
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Harimaya
authors.forename: Lawrence G
authors.initials: LG
authors.lastname: Lenke
authors.forename: Takuya
authors.initials: T
authors.lastname: Mishiro
authors.forename: Keith H
authors.initials: KH
authors.lastname: Bridwell
authors.forename: Linda A
authors.initials: LA
authors.lastname: Koester
authors.forename: Brenda A
authors.initials: BA
authors.lastname: Sides
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D008141:Lordosis; D008159:Lumbar Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods*; D010027:Osteotomy; D056888:Patient Positioning / Q000379:methods*; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D011859:Radiography; D019651:Plastic Surgery Procedures / Q000009:adverse effects / Q000379:methods; D013121:Spinal Curvatures / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects / Q000379:methods; D013131:Spine / Q000002:abnormalities / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult