title: Anatomic Considerations of Intervertebral Disc Perspective in Lumbar Posterolateral Approach via Kambin's Triangle: Cadaveric Study.
abstract: METHODS
  Anatomical study.
  
  
  OBJECTIVE
  To evaluate the anatomy of intervertebral disc (IVD) area in the triangular working zone of the lumbar spine based on cadaveric measurements.
  
  
  BACKGROUND
  The posterolateral percutaneous approach to the lumbar spine has been widely used as a minimally invasive spinal surgery. However, to our knowledge, the actual perspective of disc boundaries and areas through posterolateral endoscopic approach are not well defined.
  
  
  METHODS
  Ninety-six measurements for areas and dimensions of IVD in Kambin's triangle on bilateral sides of L1-S1 in 5 fresh human cadavers were studied.
  
  
  RESULTS
  The trapezoidal IVD area (mean±standard deviation) for true working space was 63.65±14.70 mm2at L1-2, 70.79±21.88 mm2at L2-3, 99.03±15.83 mm2at L3-4, 116.22±20.93 mm2at L4-5, and 92.18±23.63 mm2at L5-S1. The average dimension of calculated largest ellipsoidal cannula that could be placed in IVD area was 5.83×11.02 mm at L1-2, 6.97×10.78 mm at L2-3, 9.30×10.67 mm at L3-4, 8.84×13.15 mm at L4-5, and 6.61×14.07 mm at L5-S1.
  
  
  CONCLUSIONS
  The trapezoidal perspective of working zone of IVD in Kambin's triangle is important and limited. This should be taken into consideration when developing the tools and instruments for posterolateral endoscopic lumbar spine surgery.
authors: Department of Orthopedics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors: Thamrong
authors: T
authors: Lertudomphonwanit
authors: Department of Orthopedics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors: Gun
authors: G
authors: Keorochana
authors: Department of Orthopedics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors: Chaiwat
authors: C
authors: Kraiwattanapong
authors: Department of Orthopedics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors: Pongsthorn
authors: P
authors: Chanplakorn
authors: Department of Orthopedics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors: Pittavat
authors: P
authors: Leelapattana
authors: Department of Orthopedics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors: Wiwat
authors: W
authors: Wajanavisit
keywords: Endoscopic approach; Intervertebral disc; Lumbar spine; Posterolateral approach; Working zone