Cervical stenosis in a professional rugby league football player
From: Chiropractic & Osteopathy 2005, 13:15
Recommendations from the available literature at the present time suggest that conservative management of cervical discogenic pain and disc protrusion, including chiropractic manipulation and ancillary therapies, can be successful in the absence of progressive neurological deficit. The current case highlights the initial successful management of a football athlete, and the later unsuccessful management. This case highlights the issues involvement in the management of a collision sport athlete with a serious neck injury.
This case outlines a series of cervical traumas producing neck, arm and head pain. The series of injuries involved forced flexion, compression and lateral deviation away from the painful side. This mechanism is in contrast to the mechanism of extension with lateral deviation towards the painful side as described in the majority of studies of neck injuries in American football and rugby. The clinical signs suggest a disc herniation following repeated trauma resulting in compression of the C7 nerve root.
There are several studies reporting chronic recurrent cervical nerve root neuropraxia (sometimes called “chronic burner syndrome”), in American football and in rugby players. This can commonly occur during blocking, tackling or engaging in a scrum. Chronic burner syndrome can be defined as:
1) a chronic recurrent neuropraxia or axonotmesis, or both, of a nerve root associated with prolonged weakness,
2) time loss from practice and games, and
3) recurrence
Nerve root compression in the intervertebral foramina secondary to disc herniation or degenerative changes, or both, is the most common cause in football players seen with recurrent or chronic burners. In such cases, degenerative changes frequently present with concurrent cervical canal stenosis and can predispose injury.
A correlation seems to exist between chronic recurrent cervical nerve root neurapraxia and cervical canal stenosis in tackled football players and risk of more serious cervical spine injury increases with increasing stenosis. A spinal canal-vertebral body ratio (Pavlov’s ratio) on lateral radiographs of 0.80 or less (normal ratio 1:1) at one or more levels has been found in a tackle football population who have experienced an episode of cervical cord neuropraxia manifested by sensory and/or motor symptoms. Despite a series of minor neurological insults, no correlation between the prodromal episodes of cord neuropraxia and occurrence of permanent quadriplegia has been found. Also, the presence of uncomplicated developmental narrowing of the stable cervical spine does not predispose permanent neurological injury.
Absolute contraindications to continued participation in contact sports has been recommended to apply to those individuals who have had a documented episode of cervical cord neurapraxia associated with the following:
• ligamentous instability,
• intervertebral disc disease with cord compression,
• significant degenerative changes,
• MRI evidence of cord defects or swelling,
• positive neurological findings lasting more than 36 hours,
• more than one recurrence
The extremely low predictive value of Pavlov’s ratio (as an indicator of clinically relevant spinal stenosis) precludes its use as a screening mechanism for determining participation in contact activities. To accurately assess spinal canal stenosis, cross-sectional imaging technology such as MRI, contrast positive CT, and myelography should be employed. Plain radiographic identification of a narrow spinal canal in a player sustaining cervical cord neuropraxia warrants MRI investigation to rule out soft tissue based stenosis.
Most of the literature on cervical spine injuries in football, such as burner syndrome, emphasises an extension type mechanism of injury. In our case, the mechanism of injury involved both hyperflexion and a compressive force. As hyperflexion involves more compressive load to the cervical spine than extension, this combination has a greater potential for injury, particularly if a stenosis situation concurrently exists.
With cervical hyperflexion, the spinolaminar line of the superior vertebra and the posterior superior aspect of the vertebral body below approximate, resulting in a rapid decrease of the spinal canal with compression of the spinal cord. The brief, sudden deformation of the cord is thought to produce disturbed sensory and motor function below the involved level. In most instances of acute spinal injury, disruption of cord function is the result of local cord anoxia and increased concentration of intracellular calcium. Playing with improper technique, such as spear tackling, has been associated with catastrophic injuries. In the case presented in this report, the technique of running at a tackler with neck hyperflexion before impact contributed to the repetitive history of injury and should have been corrected.
Hyperflexion injuries in Whiplash Associated Disorders do not involve the exact same mechanism of injury (i.e. absence of axial compression) but the soft tissue damage can be very similar. For example, Grade III Whiplash Associated Disorder features include: cervical herniated disc, cervicalgia with headaches and limited range of motion combined with neurologic symptoms and signs are present.
With compression, a force exerted through the crown of the head can be transmitted through the skull to the cervical vertebrae resulting in the crushing of the vertebrae and extrusion of the vertebral body and disc material posteriorly into the cervical vertebral canal. When the cervical spine is in hyperflexion with rotation, vertebral dislocation without fracture is possible, which is more likely if the head is locked on the ground adding a compressive force. The most damaging mechanisms of injury to the spine are torsional and combined motions (i.e. forward flexion and lateral rotation) with a combined axial load.
The practitioner should be mindful of the potential for iatrogenic joint instability to occur. Damage to the supporting structures resulting in hypermobile joints can be aggravated by and result from repeated manipulations. The recommended management protocol for Grade III Whiplash Associated Disorders, which is a similar injury, and could be viewed as a guideline for management of footballers with cervical stenosis.
This case report has outlined the progression of cervical injury to a disc protrusion resulting in a C7 radiculopathy in a professional rugby league player, due to numerous blows to the cervical spine after a series of hyperflexion injuries. The patient ultimately suffered a severe forced flexion combined with left lateral flexion injury to the cervical spine and experienced sensory and motor changes in the right C7 nerve root distribution. When it became apparent that there was intervertebral foramen encroachment secondary to a disc protrusion the treatment protocol changed toward a more conservative approach.
