title: Unrecognized ligamentous instability due to high-energy, low-velocity mechanism of injury.
abstract: We report a unique mechanism of injury and illustrate the difficulties of diagnosing purely ligamentous injuries to the cervical spine. To our knowledge, there have been no previous reports of this type of high-energy, low-velocity mechanism of injury. The pattern of injury is also unusual, consisting of anterolisthesis of L4 on L5 with bilateral perched facet joints, atlantoaxial instability and bilateral lower limb fractures. We present a 49-year-old man who experienced a high-energy, low-velocity crush injury that led to extreme hyperflexion of his spine. Standard trauma protocols were carried out, yet atlantoaxial instability was not diagnosed until 3 days post-operatively, when the patient went into respiratory failure due to high spinal cord compression. We fused the C1/2 vertebral bodies using Harm's technique; the patient exhibited no long-term spinal cord dysfunction. Although uncommon, if left undiagnosed or not considered, purely ligamentous injuries to the cervical spine can result in catastrophic complications. Such injuries are an important subgroup to be considered at the time of initial assessment. Furthermore, when managing the multi-trauma patient, clinicians must remember not to overlook the atlantoaxial joint, as high-energy, low-velocity injury to the cervical spine may lead to silent, life-threatening instability that may not be apparent on routine imaging.
authors.affiliation: Department of Neurosurgery, Prince of Wales Hospital, Randwick, New South Wales, Australia. joeduss@hotmail.com
authors.forename: J R
authors.initials: JR
authors.lastname: Dusseldorp
authors.forename: M
authors.initials: M
authors.lastname: Ow-Yang
authors.forename: R J
authors.initials: RJ
authors.lastname: Mobbs
mesh_terms: D000062:Accidents, Occupational; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging / Q000293:injuries* / Q000473:pathology; D001368:Axis, Cervical Vertebra / Q000000981:diagnostic imaging / Q000473:pathology; D001863:Bone Screws; D001270:Cervical Atlas / Q000000981:diagnostic imaging / Q000473:pathology; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries* / Q000473:pathology; D003951:Diagnostic Errors / Q000517:prevention & control*; D005360:Fibula / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology; D006801:Humans; D016268:Internal Fixators; D008022:Ligaments / Q000000981:diagnostic imaging / Q000293:injuries*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011128:Polyradiculopathy / Q000209:etiology; D012131:Respiratory Insufficiency / Q000209:etiology; D013117:Spinal Cord Compression / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods; D013124:Spinal Injuries / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D013977:Tibia / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology; D013978:Tibial Fractures / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014947:Wounds and Injuries / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology