title: Magnetic resonance imaging-based anatomical study of the multifidus-longissimus cleavage planes in the lumbar spine.
abstract: OBJECTIVE
  The Wiltse approach allows spinal surgeries to be performed with minimal soft tissue trauma. The purpose of this study was to investigate the anatomy of the natural cleavage plane between multifidus and longissimus at different levels based on MRI images.
  
  
  METHODS
  MRI cross-sectional scans from L1 to S1 were collected from 205 out patients (103 males, 102 females). Based on the images, some parameters were defined and measured to describe the locations, curvature and directions of Wiltse approach. Besides, differences of these parameters between genders and segments were compared.
  
  
  RESULTS
  Among the total of 2460 one-sided images, cleavage planes between multifidus and longissimus were not able to be identified in 105 images. The locations, directions and curvature of the cleavage plane differed significantly among different segments but followed some regular pattern from L1-S1. The simultaneous rotation of the plane around its deepest points to the midline from S1 to L1 and the plane seemed to be the most curved at L3 and relatively straight for L5 and S1.
  
  
  CONCLUSIONS
  With a better understanding of the natural cleavage plane between multifidus and longissimus, performers can correctly plan the distance of skin incisions from the midline and the direction of muscle dissection at each vertebral level, thus reducing trauma in the operation.
authors.affiliation: Department of Orthopaedics, The Taizhou People's Hospital Affiliated to Nantong University Taizhou 225300, China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University Nanjing 210029, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Radiology, The Taizhou People's Hospital Affiliated to Nantong University Taizhou 225300, China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Orthopaedics, The Second Affiliated Hospital of Nanjing Medical University Nanjing 210011, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Xie
authors.affiliation: Department of Orthopaedics, The Taizhou People's Hospital Affiliated to Nantong University Taizhou 225300, China.
authors.forename: Weizhong
authors.initials: W
authors.lastname: Tian
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University Nanjing 210029, China.
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Cao
keywords: MRI; Wiltse; anatomy; lumbar spine; minimal invasive