There are seven cervical vertebrae and eight cervical nerves.

Spinal nerves exit above the vertebral body for which they are named; for example, the sixth cervical nerve exits at the C5–6 disc space.

The cervical spine is divided into upper and lower segments. The upper segment includes C1 (the atlas) and C2 (the axis). The spinal cord occupies a little space because the canal is normal shaped. The atlas (C1) and the occiput account for 40% of cervical flexion. The axis (C2) has a finger-like projection, the dens, about which the Allis rotates; this accounts for 60% of cervical rotation. The key for C1 and C2 stability is the transverse atlantal ligament, which lies posterior to the body of C2 and connects C1 to C2. Distraction of this ligament can cause atlantoaxial instability ( Fig. 46.1 ).

Anatomy of a vertebra.

The lower segment of the cervical spine includes C3–T1. The bony structure is relatively constant, with anterior column support provided by the anterior longitudinal ligament and the vertebral bodies in the discs. Posterior column support is supported by the posterior longitudinal ligament, facet articulation, facet capsule, interspinous ligament, and supraspinous ligament. The spinal cord occupies 75% of the canal at this level. Clinically, the space available for the spinal cord (SAC) ranges between 13 and 23 mm. The cord is stenotic when the available space is <13 mm. Typically, cord compression is present when the available space is <10 mm.

First, the physician should enquire if and where the athlete has symptoms. Does the athlete have full movement and sensation of the extremities?

The physician should then ask about the injury, including the direction of the athlete’s helmet at the time of injury as well as the radiation of symptoms and their resolution.

The athlete must be removed from the field in a safe and protected manner. Six people who have practiced the maneuver before injury, must logroll the athlete onto a spine board and safely transport the athlete to the sidelines. The helmet should not be removed, but the airway must be protected and maintained. The physician and trainers should be familiar with the removal of all types of facemasks. A power screwdriver is essential to accelerate facemask removal.

A patient with pain must be examined with palpation.

A fracture of the cervical spine may present with minimal pain, and the physician as well as the medical staff should be aware of this fact.

Athletes who are suspected to have cervical spine injuries should be immobilized.

If only radicular symptoms are present, the athlete should be examined for range of motion of the cervical spine, followed by a neurologic evaluation.

Although this examination is not a complete and thorough workup, it should be performed at a later date.

Strength is tested by comparing both sides at a scale of 0–5 (5/5 indicates full strength). The deltoids are checked with the corresponding C5 nerve root. The biceps correspond to C6 and the triceps correspond to C7.

Sensation is checked with the thumb dorsally placed corresponding to C6, the long finger corresponding to C7, and the little finger corresponding to C8.

Reflexes are then checked with the biceps reflex corresponding at the elbow to C6 and the triceps to C7.

Spurling’s test may be performed if fractures have been ruled out with the athlete’s head being rotated and extended toward the affected extremity ( Fig. 46.2 ).

Cervical disc herniation: clinical manifestations.

A positive Spurling sign is elicited when pain is exacerbated with this maneuver and is often caused by impingement of I nerve root with disc herniation or osteophytes.

Description: This is a stretch injury of the nerve root.

Mechanism: Typically, hyperextension of the neck with lateral deviation of the head

Presentation: Typically, there is a stinging or burning pain into the shoulder arm or hand, which may be accompanied by weakness of the affected upper extremity. There may be numbness or tingling. Symptoms typically last from seconds to minutes but can last from days to weeks. The incidence of such injuries is 65% in college football athletes, with an 87% risk of recurrence.

Differential diagnoses: Cervical fracture or cervical herniation

Diagnostics: Cervical radiographs should be recorded in flexion and extension to rule out instability. Ideally, the T1 vertebral body must be included in the radiographs. Magnetic resonance imaging (MRI) may be required if symptoms persist.

Treatment: The athlete is rested until full strength has returned and sensation has returned to normal. Pad modification to prevent lateral deviation of the cervical spine may be beneficial. In addition, positional change may be beneficial as well (e.g., change from right to left guard).

Prognosis: The athlete is allowed to return to play when full range of motion and strength as well as sensation have returned. The return-to-play prognosis for such injuries is typically extremely good.

Description: Pathologic insult to the spinal cord, which may or may not be accompanied by transient hypoxemia to the spinal cord

Mechanism: With flexion of the cervical spine, the cord is pinched between the superior spinolaminar line and the superior aspect of the posterior lower vertebral body.

Presentation: An athlete will typically experience sudden attack of paralysis after a tackle or being struck. The paralysis may occur in all 4 limbs or be limited to the upper body. Weakness is typically short-lived, lasting only minutes, but can last from hours to days. Sensory changes may be present as well.

Physical examination: The airway must be cleared and maintained if there is loss of consciousness. A gross neurologic examination must be performed. The physician must check for upper motor neuron signs such as hyperreflexia. Reflexes of the upper and lower extremity must be tested. Strength and sensation of the upper and lower body must be assessed as well.

Differential diagnoses: Cervical herniation, cervical fracture, and cervical fracture with dislocation

Diagnostics: Radiography

The port ratio is determined by comparing the space from the back of the vertebral body to the spinolaminar line with the width of the vertebral body. The port ratio should be >0.8; a value less than this indicates spinal stenosis as well as the risk of recurrence. AP and lateral radiographs should be obtained. A CT scan can help to delineate any fractures in the bony structures. An MRI will help delineate any pathologic damage to soft tissue structures.

Treatment: Careful observation of the athlete; serial observation and neurologic examinations should be performed. Diagnostic studies must be performed as well. There is not clear evidence regarding the use of steroids in such cases. Administration of a steroid regimen within 8 hours of neurologic damage has shown some improvement in certain cases. Typically, the dosage of methylprednisolone is 30 mg/kg bolus over 15 minutes and then 15 mL/kg over 23 hours.

Prognosis: Return to play is highly controversial. Several doctors believe that if there is no stenosis and no evidence of structural damage, athletes should be allowed to return to play; however, athletes must have regained full strength and sensation before returning to play.

Description: Herniated disc material protrudes through a tear in the annulus causing compression on a root and rarely the spinal cord (see Fig. 46.2 )

Mechanism of injury: Compression and rotation of the disc causes the annulus to tear. Pressure on the nucleus causes retropulsion through the tear and compression.

Presentation: A nerve root exits in the neuroforamen at the level above its vertebral body; therefore, a herniation at C5–C6 will cause compression of the sixth cervical nerve root. Athletes will likely experience corresponding radicular pain, which often radiates, along with weakness of the corresponding muscles.

Physical examination: A spurling sign may be present, which is pain radiating into the upper extremity when an athlete’s head is extended and rotated toward the affected side. The athlete must be examined for sensory loss in a dermatomal pattern and checked for muscular weakness correlating to the corresponding nerve root.

Diagnosis: MRI is typically diagnostic and will indicate presence of a hard or soft disc between the affected vertebral bodies.

Treatment: Oral steroids or epidural injections are often beneficial. Anterior cervical discectomy and fusion or a foraminotomy of the knee may be needed to decompress the nerve root.

Prognosis and return to play: Athletes may be allowed to return to play when they have regained full function without any neurologic damage.

Description: Athletes experience ≥1 episodes of cervical neuropraxia; often seen in football athletes with the propensity to hit or tackle using the crown of the head. The NFL and the NCAA have banned the use of this technique; thereafter, the incidence of such catastrophic cervical spine injuries has correspondingly decreased.

Diagnostic: Radiographs may show cervical stenosis with a positive port ratio (<0.8). Moreover, degenerative abnormalities may also be observed on radiographs. Video analysis of athletes with the crown of the head and helmet intact is a common recent practice.

Prognosis: Athletes should not be allowed to return to athletic activity.