title: Morphological changes in the human cervical intervertebral disc post trauma: response to fracture-type and degeneration grade over time.
abstract: OBJECTIVE
  In the first 24 h post-intervertebral disc (IVD) trauma, up to 75 % cell death has been reported. In addition, burst fractures cause post-traumatic disc degeneration by elevated pro-apoptotic and pro-inflammatory gene transcription. Moreover, some patients have pre-trauma degenerative disc disease. The aim of the study was to assess histological changes and cell-death over a time period of up to 1 year caused by mechanical and structural factors.
  
  
  METHODS
  116 anterior portions of IVDs of the cervical spine were studied histologically by light microscopy and ultrastructurally by transmission electron microscopy (TEM). The group was investigated with regard to three main parameters: fracture mechanism (compressive vs. tensile/shear loads), degeneration grade (low vs. high) and endplate fracture (with vs. without). Disc architecture (e.g. ruptures) was studied histologically. Cell morphology was examined ultrastructurally to quantify cell-death, healthy and balloon cells. According to ultrastructural observations, two time-groups (up to 6 days vs. later) were established. Statistical analyses were carried out within and between time-groups.
  
  
  RESULTS
  Histological changes were obvious in the annulus fibrosus where ruptures with haematoma were replaced by granulation tissue. Significant differences in cell-death were seen in the first few days due to different loads. In contrast to the more degenerated segments, low degenerated ones revealed significantly less cell death with time post-trauma. Interestingly, no difference was found between groups after the sixth day. Cell-death (mean 44 % for all investigated groups) remained high after day 6 post-trauma.
  
  
  CONCLUSIONS
  IVDs retrieved from low grade degenerated segments revealed a significant recovery, with less cell-death and a partially restored disc matrix, although cell-death remained high. Long-term clinical studies of stabilized segments arising from different fracture mechanisms are required.
authors.affiliation: Department of Traumatology, Medical University of Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria. ingrid.sitte@i-med.ac.at.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Sitte
authors.affiliation: Department of Traumatology, Medical University of Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria.
authors.forename: Miranda
authors.initials: M
authors.lastname: Klosterhuber
authors.affiliation: Department of Traumatology, Medical University of Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria.
authors.forename: Richard Andreas
authors.initials: RA
authors.lastname: Lindtner
authors.affiliation: Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Martin Cornelius
authors.initials: MC
authors.lastname: Freund
authors.affiliation: Department for Medical Statistics, Informatics and Health Economics, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Sabrina Barbara
authors.initials: SB
authors.lastname: Neururer
authors.affiliation: Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Kristian
authors.initials: K
authors.lastname: Pfaller
authors.affiliation: Department of Traumatology and Sports Medicine, Sankt Vinzenz Krankenhaus Zams, Zams, Austria.
authors.forename: Anton
authors.initials: A
authors.lastname: Kathrein
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017209:Apoptosis; D002574:Cervical Vertebrae / Q000293:injuries* / Q000473:pathology* / Q000601:surgery; D005260:Female; D006097:Granulation Tissue / Q000473:pathology; D006406:Hematoma / Q000473:pathology; D006801:Humans; D015601:Injury Severity Score; D007403:Intervertebral Disc / Q000293:injuries* / Q000473:pathology*; D055959:Intervertebral Disc Degeneration / Q000473:pathology; D017846:Longitudinal Ligaments / Q000473:pathology; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D020127:Recovery of Function; D016103:Spinal Fractures / Q000473:pathology* / Q000601:surgery; D055035:Spinal Osteochondrosis / Q000473:pathology; D013997:Time Factors; D055815:Young Adult
keywords: Apoptosis; Cell-death; Chondroptosis; Disc degeneration disease; Necrosis; Post-traumatic degeneration