title: Radiologic assessment of spinal fusion.
abstract: Since surgical fusion of the spine was first described in 1911, multiple methods have been used to assess it. Although open surgical exploration remains the standard of care for determination of fusion, it is impractical in most clinical situations. Static radiographs have long been used as a practical method of fusion assessment, but they tend to significantly overestimate the presence of a solid fusion. Dynamic radiographs improve accuracy but limitations include measurement reliability, disagreement on allowable motion, and the two-dimensional nature of radiographs. Ultimately, lack of movement at a fused segment does not confirm fusion. Radiostereometric analysis further improves accuracy; however, methodological demands make it largely impractical for routine use. CT is now widely accepted as the standard for noninvasive assessment of spinal fusion. Fine-cut imaging, multiplanar reconstruction, and metal artifact reduction have increased the ability to assess fusion on CT. However, significant concerns remain regarding the effects of high radiation exposure. Although MRI is appealing, its utility in assessing fusion remains unproven. Understanding the limitations of each technique allows judicious use of radiology in the assessment of spinal fusion.
authors.affiliation: Royal Adelaide Hospital, South Australia, Australia.
authors.forename: Michael Derrick
authors.initials: MD
authors.lastname: Selby
authors.forename: Simon Richard
authors.initials: SR
authors.lastname: Clark
authors.forename: David John
authors.initials: DJ
authors.lastname: Hall
authors.forename: Brian J C
authors.initials: BJ
authors.lastname: Freeman
mesh_terms: D018786:Bone Substitutes; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging; D017586:Diskectomy; D006801:Humans; D008279:Magnetic Resonance Imaging; D010014:Osteolysis; D011542:Pseudarthrosis / Q000000981:diagnostic imaging; D059869:Radiostereometric Analysis / Q000379:methods; D013123:Spinal Fusion; D013131:Spine / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
chemical_list: D018786:Bone Substitutes