Sports-related injuries to the cervical spine can result in several clinical syndromes. A review by Page and Guy focuses on three serious conditions that are especially common in football players: cervical cord neurapraxia, spinal stenosis, and “stingers.”
If the cervical canal is stenotic because of congenital conditions or previous trauma, any forced hyperflexion or hyperextension can result in compression of the spinal cord. Clinically, this causes neurapraxia with symptoms determined by the site and severity of compression. Cervical cord neurapraxia is a serious but rare event with an estimated incidence of 7.3 per 10,000 athletes. Multiple techniques have been developed to assess patients at risk of sports-related neurapraxia. One technique, the ratio of the canal diameter to vertebral body width (Torg ratio), radiographically determines spinal stenosis. A Torg ratio of 0.8 or less indicates significant cervical spine stenosis, but studies have reported such ratios in 33 to 49 percent of asymptomatic professional football players. In view of the rarity of neurapraxia, the Torg ratio is no longer considered useful in determining safety for sports participation. Absolute contraindications to returning to play after one episode of neurapraxia include evidence of cord damage or ligament instability, repeated episodes, and episodes lasting longer than 36 hours. Football players who experience neurapraxia have a 56 percent chance of recurrence.
Neurapraxia of the brachial plexus or cervical nerve roots, often called a stinger or burner, causes pain and paresthesia in a single upper extremity, usually radiating from the neck into the shoulder, arm, or hand. Stingers are the most common cervical spine–related injury in football, with a reported incidence as high as 65 percent during a player’s career. Stingers do not follow dermatomes and may be accompanied by muscle weakness. Pain and tingling usually last for a few minutes, but weakness may take days or weeks to resolve. Symptoms are caused by a traction injury (often during blocks or tackles) or more commonly by extension-compression of the neck. In older athletes, about 94 percent of persistent stingers are associated with disc degeneration or other pathology. Full evaluation and exclusion from play are indicated if stingers persist longer than 24 hours or recur. Any evidence of neurologic deficit, persistent pain, loss of motion, or cervical myelopathy requires full investigation for cervical pathology.
The authors conclude that, because of the difficulty in predicting neurapraxia and the overall controversial nature of cervical spine injury, the athlete frequently makes the final decision on returning to play.