title: The transpedicular approach as an alternative route for intervertebral disc regeneration.
abstract: METHODS
  Descriptive anatomical study on ovine and human cadaveric lumbar spinal segments.
  
  
  OBJECTIVE
  To describe the alternative transpedicular approach to deliver therapeutic agents into intervertebral disc (IVD).
  
  
  BACKGROUND
  The present delivery approach of therapeutic agents (growth factors/cells/hydrogels) within the IVD is through injection, via the annulus fibrosus (AF). However, it has recently been demonstrated that small needle puncture of the AF leads to further degeneration and disc herniation. In addition, the injected material has a high chance to be extruded through the AF injury.
  
  
  METHODS
  Lumbar ovine and human spinal segments were used. Under fluoroscopy, a 2-mm Kirschner wire was introduced in the caudal vertebra through the pedicle and the inferior endplate to the nucleus pulposus. Gross anatomy analysis and high-resolution peripheral quantitative computed tomography (HR-pQCT) were performed to assess the right position of the wire in pedicles. Discography and nucleotomy were performed using a 14G cannula insertion or a 2-mm arthroscopic shaver blade, respectively. Nucleoplasty was also performed with agarose gel/contrast agent and imaged with HR-pQCT.
  
  
  RESULTS
  Gross anatomy, fluoroscopy, and HR-pQCT images showed that the nucleus pulposus could be approached through the endplate via the pedicle without affecting the spinal canal and the neural foramina. The contrast agent was delivered into the IVD and nucleus pulposus was removed from the disc and filled with agarose gel.
  
  
  CONCLUSIONS
  This study describes how a transpedicular approach can be used as an alternative route to deliver therapeutic agents to the disc without disruption of the AF showing the potential use of this technique in preclinical research and highlighting its clinical relevance for IVD regeneration.
authors: Department of Orthopaedic and Trauma Surgery, Campus Bio-Medico University of Rome, Rome, Italy. g.vadala@unicampus.it
authors: Gianluca
authors: G
authors: Vadalà
authors: Fabrizio
authors: F
authors: Russo
authors: Girish
authors: G
authors: Pattappa
authors: Damiano
authors: D
authors: Schiuma
authors: Marianna
authors: M
authors: Peroglio
authors: Lorin M
authors: LM
authors: Benneker
authors: Sibylle
authors: S
authors: Grad
authors: Mauro
authors: M
authors: Alini
authors: Vincenzo
authors: V
authors: Denaro
mesh_terms: D000818:Animals; D002102:Cadaver; D003287:Contrast Media / Q000008:administration & dosage; D016503:Drug Delivery Systems / Q000379:methods*; D005471:Fluoroscopy; D005782:Gels / Q000008:administration & dosage; D006801:Humans; D007403:Intervertebral Disc / Q000033:anatomy & histology* / Q000502:physiology* / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery; D012038:Regeneration / Q000187:drug effects / Q000502:physiology*; D015203:Reproducibility of Results; D012685:Sepharose / Q000008:administration & dosage; D012756:Sheep; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media; D005782:Gels; D012685:Sepharose