Trauma management

Most spinal injuries are the result of high-energy trauma. Road accidents and falls are the commonest causes of injury, but in the USA gunshot injuries cause spinal injury relatively frequently. Associated injuries are common

• Spinal injury at another level                  10—15.%
• Head and face injury                               26 %
• Major chest injury                                   16 %
• Major abdominal injury                           10%
• Long bone/pelvic fracture                       8%

Ninety per cent of fractures are simple compression frac­tures and the majority of these will go on to heal with little consequence. They are best treated symptomatically, initially with rest and then with mobilisation and splinting as necessary.

Seventy-five per cent of patients with an unstable spinal injury will have some sort of neurological injury. The assess­ment of spinal stability is difficult, especially in the patient who is unconscious, and especially in the cervical spine. Look for general alignment of the spine and for soft-tissue shad­ows. Is there widening of the anterior cervical soft tissue shadow, for example? Is there subluxation or rotation of one vertebra on another? Flexion extension views can be useful (see above) but should only be done with care by suitably qualified staff.

A scoring system has been devised for assessing cervical stability.

• Anterior element disruption                       2
• Posterior element disruption                       2
• Sagittal translation >3.5 mm                      2
• Sagittal plane rotation >110                        2
• Positive stretch test                                    2
• Cervical cord injury                                   2
• Cervical root damage                                 1
• Abnormal disc narrowing                           1
• Dangerous spinal loading in the future         1

  If more than five points are scored, then the cervical spine should be considered unstable. In the thoracic and lumbar spine plain X-rays should alert the clinician to possible instability, but this may only be confirmed by CT scan in some cases. Remember that 10 per cent of all injuries are at multiple levels, so always search for the other injury.

Unstable cervical spine injuries

Adequate immobilisation of patients with unstable cervical injuries is mandatory. The patient should have a hard collar, with sandbags at either side of the head and the head should be taped to the bed until adequate treatment is started. Dislocations and fracture dislocations should be reduced as soon as possible. Delay in reduction makes it more likely that neurological injury will occur, and the longer the delay, the more difficult the reduction. However, beware of the possibility of disc prolapse in the presence of a dislocation. It is not uncommon for the intervertebral disc to prolapse posteriorly at the time of dislocation. When the dislocation is reduced, this can cause paraplegia as the spinal cord is compressed against the disc. This occurs in about 1 per cent of all these injuries. Therefore MRI scanning is mandatory before closed reduction of these fractures. If MRI scanning is not available, and not likely to be available over the following few hours, then it may be safer to carry out open anterior discectomy with fusion and instrumentation, in order to try to avoid this severe complication occurring.

Closed reduction can be best achieved either with halo traction or with Gardner Wells tongs. These are best applied under local anaesthetic which avoids any risk to the spinal cord with anaesthesia and intubation. Gardner Wells tongs are easier to apply, but do not allow correction of flexion or extension of the head once applied. The other advantage of halo traction is that the halo can then be used together with a jacket for immobilisation of the cervical spine if required (Fig 33.6 and Fig 33.7).

Neurological injury and its management

Some patients with unstable spinal column injuries will sustain damage to either the spinal cord or nerve roots. Further damage may be prevented by suitable immobilisation of the spinal column, although in a small number of patients remorseless deterioration in neurological dysfunction may occur. This is usually due to persistent compression on the spinal cord interfering with the blood supply to the neuro­logical tissues, but may be due to extension of haematoma or oedema in the area of the injury. Deterioration of neurological function following initial assessment is an indication for urgent treatment. Surgery should be considered to stabilise the spine and to decompress the spinal cord and nerve roots.

A randomised controlled study of a large group of patients has suggested that high-dose steroids may improve recovery after spinal cord injury.

 The suggested regimen is:

30 mg per kilogram of body weight bolus of methylprednisolone;

  5.4 per kilogram of body weight per hour of methylprednisolone for the first 23 hours.

There is some debate in the literature about the real efficacy of this regimen, but serious side effects are rare, and until there is evidence to the contrary it seems reasonable to offer patients high-dose steroids on presentation. If the steroids cannot be given within 8 hours, they are not effective and should be avoided.

It is important to establish as soon as possible whether the injury is incomplete or complete. Often the sacral nerve roots are the least affected in spinal injury probably because they are protected to some extent from the vascular effects of injury. Sacral sensation is best assessed at the same time as the patient is log rolled to examine the spine. If sacral sensation is intact, then the injury is incomplete. If spinal shock has developed, it will not be possible to assess function below the injury until the spinal shock has resolved. Reflex arcs can function below the level of the injury without higher func­tions. The anal wink and the bulbo-cavernosus reflexes are examples of these. If they are present, one can assume that the patient is not in spinal shock. During the period of spinal shock these reflexes will be absent and it is not possible to assess whether the spinal cord injury is complete or incomplete. Spinal shock will usually resolve within 24 hours.

Assessment of neurological injury is best carried out using various scoring techniques. For grading individual muscles the Medical Research Council (MRC) grading system is best used.

MRC grading:

  0 — no contraction;

  1 — flicker of muscle contraction;

  2 — contracts with motion but not against gravity;

  3 — contracts with motion against gravity;

  4 — reduced motor power;

  5 — normal motor power.

  Frankel grading:

  A — absent motor and sensory function;

B — sensation present motor absent;

  C — sensation present, motor present but not useful (MRC grade 2/3);

  D — sensation present, motor useful (MRC grade 4/5);

  E — normal function.

With this information available it is possible to define a neurological injury, to assess improvement or deterioration, and to communicate with others in a meaningful way about the injury.

Cervical spine injuries

Upper cervical spine in juries

Severe neurological injury is rarely seen in practice because it is not usually compatible with life.

Occipital condyle injuries. These are unusual injuries which are difficult to diagnose on plain films. If this type of injury is suspected, CT scanning is the best method of investi­gation. Some of these injuries are unstable, and if so occipito­cervical fusion should be considered.

Jefferson fractures. This is a fracture of the ring of C1 and is usually caused by axial loading (Fig. 33.8). The ring can be split in two, three or four places. The amount of displace­ment can be assessed on the open mouth view, and if there is more than 6.9 mm of displacement, one can assume that the transverse ligament is ruptured, which suggests that the fracture is very unstable. Although the fracture can usually be seen on plain films, CT scan is useful to define the fracture pattern and to be sure that there is no associated injury at adjacent levels.

If the transverse ligament is divided a period of traction may be advisable. We usually treat these fractures in a halo jacket for 3 months; CT scan followed by supervised flexion extension radiographs is advisable at that point to be sure that healing has occurred and that there is no residual instability. Occasionally one part of the ring may fail to heal but the spine may still be stable. Persistent instability or failure to heal requires posterior occipitocervical fusion.

Odontoid fracture. This is the most commonly missed fracture in the cervical spine and comprises 10 per cent of cervical injuries. Failure to diagnose these fractures can result in spinal cord damage and death. Three types of fracture are described (see Fig. 33.9). Type 1 fractures are rare and ate usually stable and can be treated symptomatically. Type II fractures (Fig. 33.10) cause the most problems because there is a high incidence of nonunion, especially in displaced fractures (up to 70 per cent). Undisplaced fractures can be treated with halo-jacket immobilisation, although it is also possible primarily to internally fix the fracture with one or two screws through an anterior approach. Displaced frac­tures can also be treated with anterior fixation which is quite a difficult technique, or with the more traditional technique of posterior C1—C2 fusion. In older individuals a period of immobilisation in a halo or even a sterno-occipitomandibular immobilizer (SOMI) collar may be considered, because they may heal in a stable position, even though the fracture itself does not unite. They are likely to put less demand on their neck, but stability should be assessed at the end of treatment with supervised flexion extension radiographs.

Type III fractures have a much better ability to heal and immobilisation in a halo jacket for 3 months will usually allow the fracture to heal. Again in the very old immobilisation in a SOMI brace or even in a Philadelphia collar may be adequate to allow healing. During treatment the position of the fracture should be monitored, and adjustments made to the position of the head as required to hold the fracture reasonably reduced.

Atlantoaxial instability. This is a common presentation in children and usually presents as inability to straighten the head, which tends to look right or left and slightly up, the so-called cock-robin position. The rotation may be fixed and often follows minor trauma, although it can present spontaneously, or occasionally as a result of local infection in the neck or oropharynx, so a careful examination of the head and neck is required. The diagnosis is made with radiographs and CT scans with the patient looking right and left. If the position of the axis is fixed in relation to the atlas on the two views, then fixed atlantoaxial rotation can be diagnosed. The subluxation can usually be corrected by a short period of halter traction, but occasionally surgery in the form of fusion is required.

Hangman’s fracture (Fig. 33.11). This is really a fracture of the pedicle of C2. It comprises 5—10 per cent of cervical injuries, and is caused by hyperextension of the spine. There are three types, type I being the most stable, and type III the most unstable. Type I fractures can be immobilised for 3 months in a halo jacket or in a suitable brace, and they will usually heal. The more unstable the fracture the more likely that spinal fusion will be required as primary treatment. If conservative treatment is chosen for unstable fractures, it is important that the fracture is reduced and held reduced until fracture healing has occurred. This can be established with supervised flexion extension radiographs to check for stability and with CT scans to look for bridging of the fracture.

Lower cervical spine in juries

Wedge fractures. These are the commonest fractures, and are caused by hyperflexion of the spine, but they must be differentiated from burst fractures (see below). This can be done with CT scan. Symptomatic treatment is the rule, and surgery is rarely indicated.

Burst fractures and teardrop fractures. Burst fractures are caused by hyperflexion of the spine with or without axial compression. Fragments of bone are pushed circumferential­ly, whereas in wedge fractures the bone is simply compressed. Thus, the spinal cord or nerve roots may be compromised, and the majority of these fractures should be considered unstable. They should be treated either with immobilisation or with surgery in the form of fusion and instrumentation.

Teardrop fractures (Fig. 33.12) are really fracture dislocations where part of the injury goes through the lower part of the vertebra and part of the injury is ligamentous. These fractures often look quite benign on radiographs, but they are very unstable and should be treated with respect. Stabilisation is often necessary.

Facet dislocation. These injuries are caused by flexion or flexion and rotation. Either one or both facets may be dis­located (and this can usually be decided on plain films, where if there is less than 25 per cent displacement of one vertebra on the other it is probably one facet, whereas if there is more displacement it is probably both facets). About two-thirds of these patients have some sort of neurological injury, and a third have a complete cord injury. These dislocations should be reduced as soon as possible, provided an anterior disc prolapse has been excluded (see assessment above). If the patient has a complete cord injury, the dislocation can simply be reduced on traction (see Fig. 33.13).

Facet dislocations are unstable and once reduced, internal fixation and bone grafting is recommended.

  Thoracic and thoracolumbar fractures

These fractures can be classified according to the mechanism of injury or according to the classification method developed by the AO. This classification corresponds with an increasing degree of injury and increasing incidence of neurological injury. It is helpful for communication and for classification in research.

Thoracic fractures (T1 —T9)

 As in other areas of the spine the commonest fractures are wedge fractures, in the elderly often associated with osteoporosis. These stable fractures can be safely managed with pain relief and mobilisation. Occasionally bracing can be helpful for pain relief.

The spine is splinted by the ribs. Other patterns of fracture are often caused by high-energy injuries, and multiple injuries are not uncommon in these patients. Thoracic fractures and sternal fractures are often associated with aortic rupture, and a high index of suspicion is recommended in the patients. CT scanning will help to make the diagnosis.

Some thoracic fractures can be very difficult to diagnose, particularly in the upper part of the thoracic spine. Careful clinical examination should exclude these fractures in the conscious patient, but in the unconscious patients radiographs of the spine must be carefully examined, with a low threshold for carrying out CT scans.

Unstable thoracic fractures can easily displace in the first few hours after a fracture and great care must be taken when moving the patient. Early posterior stabilisation of these fractures is recommended.

Thoracolumbar fractures (T10—L5)

These fractures are more common than thoracic fractures because this part of the spine is not splinted by the ribs. The most common fractures are T12 and L1 because these are at the junction between the stiff thoracic spine and the mobile lumbar spine.

Stable wedge fractures are commonest and can be treated either with mobilisation alone or with bracing initially for pain.

Unstable fractures may cause spinal cord injury or nerve root injury depending on the level of the injury.

Burst fractures may be stable or unstable. If the posterior elements are intact, then the fracture can be considered stable. Unstable fractures can usually be diagnosed on the plain radiographs, with what may appear to be a fracture similar to a wedge fracture, but with widening of the distance between the pedicles (see Fig. 33.14). This implies a fracture of the anterior structures (the body) and the posterior structures (the pedicles). It may however be necessary to carry out a CT scan to see whether the posterior elements are frac­tured. Clinical examination in the conscious patient will allow some assessment of the posterior structures. If there is no pain and no palpable defect, then the injury is probably stable. In the unconscious patient this may be more difficult and occasionally MRI scans are necessary to assess the whether posterior elements adequately to see if there is ligamentous damage.

Distraction injuries are more commonly associated with neurological injury and are usually unstable injuries. Most of these injuries are a combination of bone and soft-tissue injury, but some pass through the bone alone, so-called chance fractures. Many of these fractures are associated with intra-abdominal injury and careful examination of the abdomen is important.

Rotational injuries are the most common and are usually caused by a combination of forces. They are associated with the highest incidence of neurological injury and are best treated with reduction and internal fixation.

Unstable fractures are best treated with posterior stabilisanon of the spine but if there is associated neurological injury, particularly at the level of the conus (T12/L1), anterior vertebrectomy and stabilisation is probably best in order to decompress the spinal cord adequately. In the lumbar spine it is important that fixation is limited to the minimum number of levels in order to maintain lumbar mobility.