title: Risk of graft fracture after dorso-ventral thoraco-lumbar spondylodesis: is there a correlation with graft size?
abstract: METHODS
  Retrospective clinical study in patients with dorso-ventral thoraco-lumbar spondylodesis.
  
  
  OBJECTIVE
  To investigate whether the ratio between graft cross sectional area and the surface area of the adjacent endplates has any effect on the midterm stability of the spondylodesis. Dorso-ventral spondylodesis in the region of the thoraco-lumbar spine is one of the most frequent operations in orthopaedic surgery. Anterior stabilization with autologous iliac crest graft currently is a standard approach in many hospitals. Although numerous recommendations are given how to perform this technique, no clinical advice is available with regard to minimum graft size.
  
  
  METHODS
  Sixty-four-slice CT-scans were obtained from 82 patients 4-12 months after posterior spondylodesis with anterior implantation of iliac crest graft and stabilization with an internal fixator. The scans were analyzed using image analysis software. First, the cross sectional area of the graft was calculated and then the surface area of the adjacent endplates. The ratio between graft cross sectional area and endplate surface area was then calculated from these two values. The grafts were then evaluated in sagittal reconstruction for signs of fracture.
  
  
  RESULTS
  The probability for graft fracture in autologous tricortical grafts was >0.1% (p < 0.001) if the graft cross sectional area exceeded 23.9% of the surface area of the adjacent endplates. Patients with lower ratio values had a higher fracture risk and below a value of 10% all grafts fractured.
  
  
  CONCLUSIONS
  The relationship between graft cross sectional area and adjacent endplate area has an important effect on graft midterm stability in ventral spondylodesis of the thoraco-lumbar spine. In our opinion, the risk of graft fractures in dorso-ventral spondylodesis can be reduced by implantation of an appropriately sized graft without any additional procedures or instrumentation.
authors: Department of Orthopedic and Trauma Surgery, Albert-Ludwigs-University of Freiburg Medical Center, Hugstetterstr. 55, 79106 Freiburg, Germany.
authors: David
authors: D
authors: Kubosch
authors: Stefan
authors: S
authors: Milz
authors: Christian
authors: C
authors: Lohrmann
authors: Karsten
authors: K
authors: Schwieger
authors: Lukas
authors: L
authors: Konstantinidis
authors: Christoph M
authors: CM
authors: Sprecher
authors: Norbert P
authors: NP
authors: Südkamp
authors: Peter C
authors: PC
authors: Strohm
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016025:Bone Transplantation / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D016268:Internal Fixators; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D013122:Spinal Diseases / Q000453:epidemiology* / Q000601:surgery*; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology*; D013123:Spinal Fusion / Q000009:adverse effects* / Q000592:standards; D013904:Thoracic Vertebrae / Q000601:surgery; D055815:Young Adult