title: Anatomical analysis of the relation between human ligamentum flavum and posterior spinal bony prominence.
abstract: BACKGROUND
  Posterior spinal bony prominences are commonly used as landmarks during posterior spinal surgery; however, the exact relationship of these structures with ligamentum flavum (LF) borders and attachments has not been clarified.
  
  
  METHODS
  Whole spines were removed en bloc from 20 embalmed human cadavers. Plain radiographs and computed tomography (CT) scans of each whole spine were taken, and then the spine was divided in two parts along the pedicle bases. The LFs were painted with contrast dye, and second radiographs and CT scans were taken again. Radiographic data were analyzed using CT image analyzer.
  
  
  RESULTS
  The craniolateral border of LF at four upper lumbar levels (from L1/2 to L4/5) located cranial to isthmus in both sides (3.5 mm), meanwhile, it located at or below isthmus in both sides at L5-S1 level (0.5 mm). In the midline, LF attached below the isthmus levels at four upper lumbar levels (4 mm), though it located in the same level of isthmus at L5-S1 (1 mm). The mean distance between medial border of pedicles and lateral border of LF increased from upper to the lower lumbar levels (6.5 mm at L1/2 - 11.4 mm at L5-S1). Distance between interlaminar space and cranial border of LF at the midline gradually increased from 8.2 mm at L1 toward 11.1 mm at L4, it was 9.3 mm in L5.
  
  
  CONCLUSIONS
  From the data of new analytical method using contrasted LF and reconstructed CT, the detailed relations between bony prominence and the border of LF were uncovered. Based on these findings and reconstructed LF images superimposed on lamina, surgeons would design safe and adequate lumbar spinal decompression with imagination of overall pictures of the LF from the dorsal side.
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Javid
authors.initials: J
authors.lastname: Akhgar
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan. Electronic address: hterai@med.osaka-cu.ac.jp.
authors.forename: Hidetomi
authors.initials: H
authors.lastname: Terai
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Mohammad Suhrab
authors.initials: MS
authors.lastname: Rahmani
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Tamai
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Akinobu
authors.initials: A
authors.lastname: Suzuki
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Toyoda
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hoshino
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Ikebuchi
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Sayed Abdullah
authors.initials: SA
authors.lastname: Ahmadi
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D004210:Dissection; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D017843:Ligamentum Flavum / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008159:Lumbar Vertebrae / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008297:Male; D012680:Sensitivity and Specificity; D013131:Spine / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods