Understanding neck injuries in football players starts with understanding how the game is played -- not the strategy, but the training techniques and requirements of the game. Neck injuries are an unavoidable part of the game. What can be improved are the preventative measures, the treatment techniques, and some standardization of risk factors in playing after a neck injury.2
Analysis of epidemiological data and cinematographic documentation clearly demonstrated that the majority of cervical fractures and dislocations are due to axial loading.3 On the basis of this observation, rule changes banning both deliberate "spearing" and the use of the top of the helmet as the initial point of contact in making a tackle were implemented at the high school and college level. Subsequently, a marked decrease in cervical spine injury rates has occurred. The occurrence of permanent cervical quadriplegia decreased from 34 in 1976 to five in the 1984 season. It is suggested that axial loading of the cervical spine is also responsible for the catastrophic injuries in diving, rugby, ice hockey and gymnastics. Implementation of appropriate changes in playing techniques and/or equipment modifications could possibly reduce the incidence of cervical spine injuries in these activities as well.
Athletic injuries to the cervical spine associated with quadriplegia occur as a result of axial loading.4 Whether it is a football player striking an opponent with the top or crown of his helmet, a poorly executed dive into a shallow body of water where the subject strikes his head on the bottom, or a hockey player pushed into the boards head-first, the fragile cervical spine is compressed between the rapidly decelerated head and the continued momentum of the body.
Appropriate rule changes recognizing this mechanism have resulted in a reduction of football quadriplegia by two-thirds. Presumably, educational efforts designed to inform the public of the dangers of diving would have a similar effect. The predominance of the axial loading mechanism is not as clearly defined in trampoline and mini-trampoline injuries. However, both of these devices are dangerous when used in the best of circumstances, and their use has no place in recreational, educational or competitive gymnastics. The emergence of severe cervical spine injuries resulting from ice hockey is recognized. Sound scientific methods of modifying the games to prevent these injuries are lacking.
Bruce5 reports that 80% of severe sports-related central nervous system trauma occurs as a result of collision sports, chiefly American football and rugby union football, followed by wrestling and gymnastics. Although serious head injury is uncommon, episodes of concussion are frequent. Repeated concussion should be grounds for suggesting that the athlete give up collision sport. American and rugby union football are the sports mainly responsible for cervical spine injury with resultant quadriplegia.
Hill et al.,6 state there is a clear division of patients into a group aged eight years or less with exclusively upper cervical injuries, and an older group with pancervical injuries. In the younger children, the injuries involved soft tissue (subluxation-dislocation is seen more frequently than fracture), and tended to occur through subchondral growth plates, with a more reliable union than similar bone injuries. In the older children, the pattern and etiology of injury are the same as in adults. The entire cervical axis is at risk, and there is a tendency to fracture bone rather than cartilaginous structures.
Epidemiology
Those athletes with abnormal findings on screening examination were twice as likely to have a head or neck injury at some point in their college careers as those players with a normal screening examination, according to Albright.7 The greater the degree of abnormality on screening examination, the more severe the neck injury in college was likely to be.
Stenosis
Athletes found to have a congenitally narrow cervical vertebral canal followed by head trauma may present with transient quadriplegia. In my opinion, a myelogram should be made for patients with a history of transient quadriplegia, numbness, or a burning sensation down the back or the lower extremities, even if other radiographic studies are interpreted as negative. Some state that athletes who have stenosis of the cervical spine should be advised to discontinue participation in contact sports.8
Sagittal canal/vertebral body ratios were measured on cervical spine lateral radiographs of 124 professional football players and 100 rookie football players.9 A total of 894 levels were measured in 224 players. Forty of the 124 professional football players (32%), and 34% of the 100 rookies had a ratio of less than 0.80 at one or more levels from C3 to C6. The 0.80 ratio has been considered indicative of cervical spinal stenosis.
This is the first time that the incidence of spinal stenosis, as determined by Torg's ratio, has been demonstrated in a population of professional and rookie football players. Because one-third of this population has cervical spinal stenosis as determined by the Torg ratio, other factors should be considered in the evaluation of a player with a transient quadriplegic episode when making continued-play decisions.
Mortality
The data reveals that the majority of head and cervical spine fatalities are related to high-school football players either tackling or being tackled in a game. The majority of head fatalities are subdural hematomas, and almost all of the cervical spine fatalities are fractures, dislocations, or fracture-dislocations.10
Neurapraxia
The sensory changes of neurapraxia include burning pain, numbness, tingling and loss of sensation, while the motor changes range from weakness to complete paralysis. The episodes are transient and complete recovery usually occurs in 10-15 minutes, although in some patients gradual resolution occurs over a period of 36-48 hours. Except for burning paresthesia, pain in the neck is usually not present at the time of injury and there is complete return of motor function and full, pain-free motion of the cervical spine. Routine roentgenograms of the cervical spine are negative for fractures or dislocations. However, the roentgenographic findings may include developmental spinal stenosis, congenital fusion, cervical instability, or intervertebral disc disease. Using the ratio method to determine spinal stenosis, a measurement of less than 0.80 indicates significant spinal stenosis as compared with a ratio of approximately 1.00 or more in control groups. There is generally a statistically significant spinal stenosis in many of such patients.
The phenomenon of neurapraxia of the cervical spinal cord occurs in individuals with developmental stenosis of the cervical spine, congenital fusion, cervical instability, or protrusion of an intervertebral disc in association with a decrease in the anteroposterior diameter of the spinal canal. In athletes with diminution of the anteroposterior diameter of the spinal canal the spinal cord can, on forced hyperextension or hyperflexion, be compressed, causing transitory motor and sensory manifestations.11
Neck Injuries
Cervical disk injuries in football are cervical injuries associated with neurological deficits, radicular symptoms, or radiological evidence of disk degeneration, but not with a fracture or a dislocation of the cervical spine. The majority of the radicular signs and symptoms are from the fourth and fifth cervical root. The roentgenographic changes are most common at the fourth and fifth intervertebral disk spaces. Most of the cases responded satisfactorily to simple cervical collar and cervical traction. The athletes who present with radicular signs and symptoms may require up to five months to return to full sports activities, and 60% of these may have residual symptoms after completion of treatment.12
Football players with a diagnosis of "stinger" were examined and were proven to have C6 radiculopathy rather than lateral stretch of the brachial plexus.13 The most frequent mode of injury was neck flexion during tackling. The athletes should not return to competition until abnormal neurologic signs disappear.
The traumatic C3-C4 level injuries sustained by young athletes and documented by the National Football Head and Neck Injury Registry reveals that the response to energy inputs at the C3-C4 level differ from the response involving the upper (C1-C2) and lower (C5-C6) cervical segments.14 Specifically, these lesions appear unique with regard to infrequency of bony fracture, difficulty in effecting and maintaining reduction, and a more favorable response to early aggressive treatment. It is still believed that these lesions resulting from athletic activity are due to axial loading.
References
- Tucker JB, Marron JT. Fieldside management of athletic injuries. Am Fam Physician 1986;34(2):137-142.
- Watkins RG. Neck injuries in football players. Clin Sports Med 1986;5(2):215-246.
- Torg JS, Vegso JJ, Sennett B, Das M. The National Football Head and Neck Injury Registry: 14-year report on cervical quadriplegia, 1971 through 1984. JAMA 1985;254(24):3439-3443.
- Torg JS. Epidemiology, pathomechanics, and prevention of athletic injuries to the cervical spine. Med Sci Sports Exerc 1985;17(3):295-303.
- Bruce DA, Schut L, Sutton LN. Brain and cervical spine injuries occurring during organized sports activities in children and adolescents. Prim Care 1984;11(1):175-194.
- Hill SA, Miller CA, Kosnik EJ, Hunt WE. Pediatric neck injuries: a clinical study. J Neurosurg 1984;60(4):700-706.
- Albright JP, McAuley E, et al. Head and neck injuries in college football: an eight-year analysis. Am J Sports Med 1985;13(3):147-152.
- Ladd AL, Scranton PE. Congenital cervical stenosis presenting as transient quadriplegia in athletes: report of two cases. J Bone Joint Surg 1986;68(9):1371-1374.
- Odor JM, Watkins RG, et al. Incidence of cervical spinal stenosis in professional and rookie football players. Am J Sports Med 1990;18(5):507-509.
- Mueller OF, Blyth CS. Fatalities from head and cervical spine injuries occurring in tackle football: 40 years' experience. Clin Sports Med 1987;6(1):185-196.
- Torg JS, Pavlov H, et al. Neurapraxia of the cervical spinal cord with transient quadriplegia. J Bone Joint Surg (Am) 1986;68(9):1354-1370.
- Kumano K, Umeyama T. Cervical disk injuries in athletes. Arch Orthop Trauma Surg 1986;105(4):223-226.
- Poindexter DP, Johnson EW. Football shoulder and neck injury: a study of the "stinger." Arch Phys Med Rehabil 1984;65(10):601-602.
- Torg JS, Sennett B, Vegso JJ. Spinal injury at the level of the third and fourth cervical vertebrae resulting from the axial loading mechanism: an analysis and classification. Clin Sports Med 1987;6(1):159-183.
Kim D. Christensen, DC, DACRB, CCSP
Ridgefield, Washington
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