title: Indirect foraminal decompression is independent of metabolically active facet arthropathy in extreme lateral interbody fusion.
abstract: METHODS
  Retrospective analysis of prospectively collected, nonrandomized radiographical data.
  
  
  OBJECTIVE
  To examine the relationship between the presence of preoperative metabolically active facet arthropathy (FA) and the amount of indirect foraminal decompression gained after extreme lateral interbody fusion (XLIF).
  
  
  BACKGROUND
  Although evidence of significant radiographical indirect decompression after XLIF has been shown, the relationship between the extent of indirect decompression and the presence of potentially attenuating, FA is yet to be studied.
  
  
  METHODS
  A prospective database of consecutive patients undergoing XLIF was retrospectively analyzed. Posterior disc height, foraminal height, and cross-sectional foraminal area were measured on computed tomographic scans obtained preoperatively and 2 days postoperatively. The selected radiographical parameters were examined with respect to the presence of FA based on preoperative computed tomographic and bone scans.
  
  
  RESULTS
  Fifty-two consecutive patients underwent 79 levels of XLIF without direct decompression. Average age was 66.4 years and 34 (65.4%) were females. Surgery resulted in significant increases in posterior disc height 3.0 to 5.7 mm (89.0% increase), P<0.0001; foraminal height 1.4 to 1.7 cm (38.0% increase), P<0.0001; and foraminal area 1.1 to 1.4 cm (45.1% increase), P<0.0001. These increases were independent of the presence of metabolically active arthropathy.
  
  
  CONCLUSIONS
  Significant indirect neural decompression is possible in XLIF, regardless of the presence of metabolically active FA.
  
  
  METHODS
  3.
authors.affiliation: *Neuroscience Institute, Epworth Hospital, Melbourne, Victoria, Australia †Greg Malham Neurosurgeon, Melbourne, Victoria, Australia ‡NuVasive Australia & NZ Pty Ltd, Melbourne, Victoria, Australia; Departments of §Radiology and ¶Nuclear Medicine, Epworth Hospital, Melbourne, Victoria, Australia.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Malham
authors.forename: Rhiannon M
authors.initials: RM
authors.lastname: Parker
authors.forename: Ben
authors.initials: B
authors.lastname: Goss
authors.forename: Carl M
authors.initials: CM
authors.lastname: Blecher
authors.forename: Zita E
authors.initials: ZE
authors.lastname: Ballok
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging; D007592:Joint Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011843:Radiculopathy / Q000209:etiology / Q000601:surgery*; D011859:Radiography; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon; D021801:Zygapophyseal Joint / Q000000981:diagnostic imaging