Yudu - sportEX medicine - 1999-2010

WWW.SPORTEX-MEDICINE.COM Alar ligaments Occiput (C0) Tectorial membrane Posterior ligament Atlas (C1)

Axis (C2)

Following injury, appropriate investiga- tions must be carried out by the medical teams. This may consist of x-rays, com- puterised tomography (CT) scans or mag- netic resonance imaging (MRI) of the cer- vical spine. X-rays will help in diagnosing fractures or malalignment. However inter- pretation of x-rays can be difficult. For example, is there an acute injury, or is it signs of old pathology on the x-ray? In this case further investigations with CT or MRI scans are more diagnostic.

Figure 2a: Alar ligaments of C0-C1

bral bodies, and superior facets of the ver- tebrae below articulate with the inferior facets of the vertebrae above. During the movement of extension to flexion there is a translation and rotation movement.

This coupled movement is important in understanding the mechanism of injury in the cervical spine. During axial rotation and lateral flexion, a unilateral disloca- tion of a facet joint may occur.

In traumatic incidents, if one facet is pushed too far in a caudad direction and the opposite facet pushed too far in a cephalad direction, dislocation may occur. For example in rugby union this is the posi- tion adopted during engagement of a scrum or as a result of the scrum collapsing.

Signs and symptoms of injury As the cervical spinal cord is protected by the vertebrae and stability is provided by the cervical joint structures and surround- ing muscles, if the forces exceed the bio- mechanical limits, failure occurs. In trau- ma the forces may not only damage the joints but also cause breakdown of liga- ments and muscles which stabilise the cervical spine.

In diagnosis it is important to understand that in the cervical spine the anatomical arrangement of the cervical nerve roots mean the nerves exit above the corre- sponding spinal level (Fig.1). This knowl- edge aids the assessment process in determining both the cervical level, and possible severity, of the injury.

If during sports activity a cervical spine injury is suspected, the player must not be moved without appropriate transporta- tion methods ie. spinal board, stiff neck collars, ambulance. A stable fracture, or

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Figure 2b: Tectorial membrane and posterior liga- ment

dislocation without neurological signs managed inappropriately can easily have disastrous consequences. Often the player is unaware of the extent of injury due to lack of pain, and they must be instructed not to move until correct assessment has been carried out.

Assessment Neurological assessment for sensory and motor loss can be carried out on the field of play. If the player experiences any neu- rological losses listed in Tables 1 and 2 below they must be managed as for a severe neck injury until proven otherwise.

Nerve root Sensory loss C5

C7 C8 T1

Soft tissue injuries Soft tissue injuries can be minor strains of the ligaments, damage to the interverte- bral disc or strains of the paravertebral muscles of the cervical spine. These injuries usually occur by acceleration/ deceleration or contact with either an opposing player or the ground. Symptoms produced may be either neck pain or spasm in the trapezius muscle or radiating pain dermatomally if the nerve root has become inflamed.

More serious soft tissue injury leads to damage of the brachial plexus often called ‘stingers’ or ‘burners’. This is a traction

Sensation to the deltoid and lateral brachial area distal to the elbow

Sensation to lateral forearm, distal to the elbow, thumb and index finger

Sensation to upper arm, mid-palm and middle finger

Sensation to the ulnar border of the forearm, ring and little finger Sensation medial to the elbow and upper arm

Table 1: Sensory loss at respective cervical nerve root levels

Nerve root Motor loss C3 –C5

Paralysis of trunk muscles and extremities – paralysis of the diaphragm leading to abnormal respiration

C4 – C5 No movement of arms, lower extremities or trunk. Abdominal breath ing is present due to the diaphragm receiving motor fibres of the phrenic nerve C3 and C4 with upper part C5

C5 – C6 Flex the elbow joint – unable to close fingers – loss of elbow extension

C6 – C7 Able to flex/extend elbow joint – close fingers but loss of finger intrinsic muscles to spread fingers

C7 – T1 Upper limbs working – lower limb paraplegia. Abdominal muscles affected depending on spinal level

Table 2: Motor loss at respective cervical nerve root levels