title: Risk evaluation of thermal injury to the cervical spine during intradiscal laser application in vitro.
abstract: OBJECTIVE
  We aimed to investigate temperature distribution during laser and its possible thermal damage to the neurovascular structures.
  
  
  BACKGROUND
  Percutaneous laser disc decompression (PLDD) is now being performed as a minimally invasive intradiscal technique for the operative therapy of non-sequestered herniated cervical discs. As yet, no experimental basic research has been reported with regard to temperature rise and distribution in the cervical region during laser radiation.
  
  
  METHODS
  An in vitro laser procedure was performed on human cervical intervertebral discs under standardized conditions. A thermo-camera was used to monitor in real-time the zones sensitive to temperature increase.
  
  
  RESULTS
  Average intervertebral disc volume was 2000 mm3. With a total energy conduction of 600 Joules, a temperature increase of around 30 degrees C was shown with an initial temperature of 28 degrees C at the posterior longitudinal ligament lying immediately in front of the myelon. The defect volume was less than 1% of the total intervertebral disc volume.
  
  
  CONCLUSIONS
  If, during laser application, the total amount of conducted energy is too high, with an unfavorable position of the fibers in the intervertebral space, there is a risk of thermal damage to the spinal cord and nerve roots.
authors.affiliation: Orthopedics Department, Hannover Medical School, Hannover, Germany. schmolke@annastift.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Schmolke
authors.forename: Ludger
authors.initials: L
authors.lastname: Kirsch
authors.forename: Frank
authors.initials: F
authors.lastname: Gossé
authors.forename: Christian
authors.initials: C
authors.lastname: Flamme
authors.forename: Michael
authors.initials: M
authors.lastname: Bohnsack
authors.forename: Oliver
authors.initials: O
authors.lastname: Rühmann
mesh_terms: D002574:Cervical Vertebrae / Q000293:injuries*; D006801:Humans; D007834:Lasers; D013696:Temperature; D013817:Thermography