The cervical spine 4 196 Question 6 Answer Occipito-atlantal dissociation This is a generic term that refers to disruption of the occipito-atlantal articulation that includes partial (subluxation) or complete (dislocation) disruption [2]. Stability of this joint complex is primarily ligamentous. Frank occipito-atlantal dislocation is usually a fatal injury (Fig. 4.35). However, with atlanto-occipital subluxation patients may be neurologically intact. Other forms of presentation are bulbar-cervical dissociation, lower cranial nerve deficits with or without cervical cord injury, or worsening neurological deficit with application of cervical traction. The diagnosis is easily made by measuring the dens basion interval (DBI) (Fig. 4.13). The distance does not exceed 12 mm in adults or children. 28-year-old male patient. The patient required cardio-pulmonary resuscitation during ambulance transfer to hospital.  What is the prognosis (Fig. 4.35)? Fig. 4.35 Quiz case. Chap-04.qxd 09/Oct/02 11:06 AM Page 196 Trauma of the cervical spine 4 197 Fig. 4.37 Quiz case. Question 7 Male patient. Manual labourer. Struck (whilst wearing protective helmet) on top of head. Glasgow Coma Score 15/15. Neurologically intact. Complaining of neck pain (Figs 4.36–4.39).  What is the injury? Fig. 4.36 Quiz case. Chap-04.qxd 09/Oct/02 11:06 AM Page 197 The cervical spine 4 198 Fig. 4.38 Quiz case. Fig. 4.39 Quiz case. Chap-04.qxd 09/Oct/02 11:06 AM Page 198 Trauma of the cervical spine 4 199 Answer Jefferson fracture This is usually the result of a vertical compression force (‘blow out’ fracture). The classic Jefferson fracture involves fractures of both the anterior and posterior arches bilaterally. Usual radiographic features are displacement of the lateral masses of C1 beyond the margins of the body of C2 (Figs 4.36 and 4.37). There is approximately a 41% chance of an associated C2 fracture, thus CT including C1–C3 is recommended [6] (Figs 4.38 and 4.39). One important caveat; the lack of fusion of the posterior arch may be seen in adults as a congenital anomaly defined by smooth margins. This fracture is usually unstable. Usually no neurological deficit is isolated, due to fragments being forced outwards. Another important caveat is the rule of Spence. On an AP open mouth odontoid view, if the sum total of the overhang of both the C1 lateral masses relative to the body of C2 is greater than or equal to 7 mm, then the inference is that the transverse ligament is probably disrupted (which requires rigid immobilisation). Chap-04.qxd 09/Oct/02 11:06 AM Page 199 The cervical spine 4 200 Question 8 Describe the type of fracture (Figs 4.40 and 4.41). Fig. 4.40 Quiz case. Fig. 4.41 Quiz case. Answer Odontoid fracture There are three types:  type 1 – the tip of the odontoid is involved (rare usually stable);  type 2 – odontoid fracture is a fracture of the base of the odontoid (unstable у 6 mm displacement) (Figs 4.40 and 4.41); Chap-04.qxd 09/Oct/02 11:06 AM Page 200 Trauma of the cervical spine 4 201  type 3 is a fracture through the base of the odontoid that extends through the body of the C2 vertebra. This is usually a stable injury with a good prognosis, and is identified on the lateral by disruption of Harris’ ring [6] (Figs 4.42–4.44). Fig. 4.42 Dens fracture. Lateral cervical spine. A break in the inferior margin of the sclerotic ring found in the body of C2 (Harris’ ring), along with prevertebral soft tissue swelling (arrow). This indicates a type 3 dens fracture. This can be the only view where this type of fracture is identified – on the AP odontoid view (Fig. 4.44) the fracture is not visible. Fig. 4.43 Odontoid fracture (dens fracture). Lateral cervical spine (close up of Fig. 4.42). Disruption of this ring (arrow) may be the only sign of a dens fracture. Soft tissue thickening at C1 level is also present (dotted arrows). Chap-04.qxd 09/Oct/02 11:06 AM Page 201 The cervical spine 4 202 Fig. 4.44 Odontoid (dens fracture). AP peg view. Same patient as Fig. 4.42. A fracture through the body of C2 is not appreciated on the odontoid peg view. Chap-04.qxd 09/Oct/02 11:06 AM Page 202 Trauma of the cervical spine 4 203 Question 9 Fig. 4.45 Quiz case. Fig. 4.46 Quiz case. Answer Hangman’s fracture This is a traumatic spondylolisthesis of the C2 vertebral body resulting from hyperextension and distraction seen with hanging and from hyperextension and axial loading in motor vehicle accidents when the chin strikes the dashboard. 56-year-old female with long history of depression. Attempted hanging.  What is this injury called (Figs 4.45 and 4.46)? Chap-04.qxd 09/Oct/02 11:06 AM Page 203 The cervical spine 4 204 The radiographic features are  bilateral pars interarticularis fractures of C2 (Figs 4.45 and 4.46),  anterior dislocation of the C2 vertebral body,  anterior inferior avulsion fracture associated with the rupture of the anterior longitudinal ligament,  prevertebral soft tissue swelling (which can be absent at times). This type of fracture is associated with a high incidence of head injury. The fracture is usually stable, however, instability can be identified by  marked anterior displacement of C2 on C3 particularly if the degree of displacement exceeds more than 50% of the AP diameter of the C3 vertebral body,  marked motion on flexion/extension films,  excessive angulation greater than 11 degrees. Neurological deficit is rare, non-union is rare and 90% usually heal with immobilisation only [6]. Chap-04.qxd 09/Oct/02 11:06 AM Page 204 Trauma of the cervical spine 4 205 Question 10  What is the mechanism of this fracture (Figs 4.47 and 4.48)? Fig. 4.47 Quiz case. Fig. 4.48 Quiz case. Chap-04.qxd 09/Oct/02 11:06 AM Page 205 [...]... in a 40-year-old patient and the appearance in Fig 5.5 which come from an 84-year-old patient The brain volume is reduced with more prominent ventricles, cisterns and CSF spaces – there is cerebral atrophy 5 Fig 5.5 This is the brain of an 84-year-old patient The CSF spaces, ventricles and cisterns are more prominent than a younger patient and represent loss of brain volume or atrophy 223 Chap-05.qxd... crash victims: how many X-rays are enough? J Trauma 1990; 30: 392–3 97 4 Emergency and Trauma Radiology, 2000 Categorical Course Syllabus, American Roentgen Ray Society Meeting 5 Adam Greenspan Orthopedic Radiology A Practical Approach, 3rd edition, 2000 Lippincott Williams and Wilkins, Philadelphia 6 Mark S Greenberg Handbook of Neurosurgery, 5th edition, 2001 7 R.H Daffner Thoracic and lumbar vertebral... overemphasised The examples above (Figs 4.56 and 4. 57) demonstrate the pitfalls of incomplete examination of the cervical spine If the complete cervical spine cannot be visualised on plain films, then cross-sectional imaging is mandatory References 1 H.K Lyerly, J.W Gaynor The Handbook of Surgical Intensive Care, 3rd edition, 1992 2 John H Harris Jr., Stuart E Mirvis The Radiology of the Acute Cervical Spine... puncture looking for xanthochromia should be performed 226 Chap-05.qxd 09/Oct/02 11: 07 AM Page 2 27 Case illustrations Question 3 56-year-old male Alcoholic patient who has recently fallen Report the CT (Fig 5.9) How old is the abnormality? What is the further management? Fig 5.9 Quiz case Answer Acute subdural haematoma There is a large high-density crescentic extra-axial collection around the right cerebral... patient has had a head injury and so they must be considered to have a cervical spine injury until proven otherwise During intubation inline cervical stabilisation must be performed and the hard collar, sandbags and tapes replaced after intubation Ensure also that there are no other life-threatening traumatic injuries to the patient and that they are haemodynamically stable before going to the CT scan... lies and the computer for operating the scanner and viewing images The gantry is the large square giant donut with a patient aperture into which the patient is fed upon the table The gantry is composed of a generator, X-ray tube, collimator and detectors The gantry can be tilted to various degrees of angulation relative to a true perpendicular or axial slice The X-ray tube circles the patient and produces... Intravenous contrast used in CT is an iodine-based contrast similar to that used for IVPs and numerous other radiological procedures The iodine in the contrast causes X-ray absorption so that vascular structures and organs taking up the contrast medium appear more dense during the examination This improves the contrast resolution between vascular and non-vascular structures Contraindications to intravenous... renal impairment and diabetic patients taking Metformin 2 17 Chap-05.qxd 09/Oct/02 11:06 AM Page 218 CT head The contrast is administered via an intravenous cannula and the timing of administration is carefully controlled to coordinate with the timing of the CT scan Various phases of contrast enhancement occur as the bolus of contrast passes from the arterial system into the veins and is finally excreted... mediastinum, lung, liver, abdomen and bone all have different windows for image display What is spiral or helical CT? The most significant advance in CT over the past few years has been the development of spiral CT Conventional CT produces a data set for each individual slice scanned The table moves to a location and the tube rotates to acquire data and the process is repeated for the next slice/position... scan, the patient should be kept intubated and ventilated, and returned to an intensive therapy area while the case is discussed with the local neurosurgeons The use of mannitol to decrease ICP and nimodipine for vasospasm should be discussed with them If the regional neurosurgical unit is at another hospital, the patient should be transferred, intubated and ventilated by an experienced anaesthetist . then cross-sectional imaging is mandatory. References 1. H.K. Lyerly, J.W. Gaynor. The Handbook of Surgical Intensive Care, 3rd edition, 1992. 2. John H. Harris Jr., Stuart E. Mirvis. The Radiology. resulting from hyperextension and distraction seen with hanging and from hyperextension and axial loading in motor vehicle accidents when the chin strikes the dashboard. 56-year-old female with long history. many X-rays are enough? J Trauma 1990; 30: 392–3 97. 4. Emergency and Trauma Radiology, 2000. Categorical Course Syllabus, American Roentgen Ray Society Meeting. 5. Adam Greenspan. Orthopedic Radiology.