title: Comparison of CT versus MRI measurements of transverse atlantal ligament integrity in craniovertebral junction injuries. Part 1: A clinical study.
abstract: OBJECTIVE Craniovertebral junction (CVJ) injuries complicated by transverse atlantal ligament (TAL) disruption often require surgical stabilization. Measurements based on the atlantodental interval (ADI), atlas lateral diameter (ALD1), and axis lateral diameter (ALD2) may help clinicians identify TAL disruption. This study used CT scanning to evaluate the reliability of these measurements and other variants in the clinical setting. METHODS Patients with CVJ injuries treated at the authors' institution between 2004 and 2011 were evaluated retrospectively for demographics, mechanism and location of CVJ injury, classification of injury, treatment, and modified Japanese Orthopaedic Association score at the time of injury and follow-up. The integrity of the TAL was evaluated using MRI. The ADI, ALD1, and ALD2 were measured on CT to identify TAL disruption indirectly. RESULTS Among the 125 patients identified, 40 (32%) had atlas fractures, 59 (47.2%) odontoid fractures, 31 (24.8%) axis fractures, and 4 (3.2%) occipital condyle fractures. TAL disruption was documented on MRI in 11 cases (8.8%). The average ADI for TAL injury was 1.8 mm (range 0.9-3.9 mm). Nine (81.8%) of the 11 patients with TAL injury had an ADI of less than 3 mm. In 10 patients (90.9%) with TAL injury, overhang of the C-1 lateral masses on C-2 was less than 7 mm. ADI, ALD1, ALD2, ALD1 - ALD2, and ALD1/ALD2 did not correlate with the integrity of the TAL. CONCLUSIONS No current measurement method using CT, including the ADI, ALD1, and ALD2 or their differences or ratios, consistently indicates the integrity of the TAL. A more reliable CT-based criterion is needed to diagnose TAL disruption when MRI is unavailable.
authors.affiliation: Spinal Biomechanics Laboratory and.
authors.forename: Luis
authors.initials: L
authors.lastname: Perez-Orribo
authors.affiliation: Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Snyder
authors.affiliation: Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Samuel
authors.initials: S
authors.lastname: Kalb
authors.affiliation: Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Ali M
authors.initials: AM
authors.lastname: Elhadi
authors.affiliation: Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Forrest
authors.initials: F
authors.lastname: Hsu
authors.affiliation: Spinal Biomechanics Laboratory and.
authors.forename: Anna G U S
authors.initials: AG
authors.lastname: Newcomb
authors.affiliation: Spinal Biomechanics Laboratory and.
authors.forename: Devika
authors.initials: D
authors.lastname: Malhotra
authors.affiliation: Spinal Biomechanics Laboratory and.
authors.forename: Neil R
authors.initials: NR
authors.lastname: Crawford
authors.affiliation: Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Theodore
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries*; D005260:Female; D006801:Humans; D008022:Ligaments / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D012189:Retrospective Studies; D012886:Skull / Q000000981:diagnostic imaging / Q000293:injuries*; D016683:Supine Position; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: ADI = atlantodental interval; ALD1 = atlas lateral diameter; ALD2 = axis lateral diameter; CVJ = craniovertebral junction; GCS = Glasgow Coma Scale; TAL = transverse atlantal ligament; atlantoaxial overhang; atlantodental interval; atlas fracture; axis fracture; cervical; mJOA = modified Japanese Orthopaedic Association; measurement; transverse atlantal ligament