Catastrophic Sports Injuries

Barry P. Boden

INTRODUCTION

In the United States, approximately 10% of all brain injuries and 7% of all new cases of paraplegia and quadriplegia are related to athletic activities (15).
Information on catastrophic injuries in athletes is collected by the National Center for Catastrophic Sports Injury Research (NCCSIR), the U.S. Consumer Product Safety Commission (CPSC), and the professional league data registries.
The NCCSIR defines catastrophic sports injury as “any severe spinal, spinal cord, or cerebral injury incurred during participation in a school- or college-sponsored sport.” Concussions are not considered to be catastrophic injuries.
The NCCSIR classifies injuries as direct, resulting from participating in the skills of a sport (i.e., trauma from a collision), or indirect, resulting from systemic failure due to exertion while participating in a sport.
The NCCSIR subdivides catastrophic injuries into three categories: fatal, nonfatal, and serious. A nonfatal injury is any injury where the athlete suffered a permanent, severe, functional disability. A serious injury is a severe injury with no permanent functional disability (e.g., a fractured cervical vertebra without paralysis) (15).
The CPSC operates a statistically valid injury and review system known as the National Electronic Injury Surveillance System (NEISS) (26). The NEISS estimates are calculated using data from a sample of hospitals that are representative of emergency departments in the United States. The CPSC does not provide data on injury specifics nor does it include information on injuries that initially presented to physician offices.
The National Collegiate Athletic Association (NCAA) and the National Federation of State High School Associations (NFHS) review injury epidemiology annually and publish a rules book for each sport with the intent of promoting safe play (17,18).

EPIDEMIOLOGY

For all sports followed by the NCCSIR, the total direct and indirect incidence of catastrophic injuries is approximately 1 per 100,000 high school athletes and 4 per 100,000 college athletes (16).
The combined fatality rate for direct and indirect injuries in high school is 0.40 for every 100,000 high school athletes and 1.42 for every 100,000 college participants (16).
Football is associated with the greatest number of catastrophic injuries for all major team sports.
Pole vault, gymnastics, ice hockey, and football have the highest incidence of injury per 100,000 male participants (16).
Cheerleading is associated with the highest number of direct catastrophic injuries for all female sports (16).

INDIRECT INJURIES

Indirect or nontraumatic deaths in athletes have been identified to be predominantly caused by cardiovascular conditions such as hypertrophic cardiomyopathy (HCM), cardiac artery anomalies, myocarditis, aortic stenosis, and dysrhythmias. The most common etiology of sudden cardiac death is HCM for those under age 35 and coronary artery disease for those over age 35. Noncardiac conditions that cause fatalities are heat illness and miscellaneous diagnoses such as rhabdomyolysis, status asthmaticus, and electrocution caused by lightning.

Cardiac Conditions

Most young athletes who die suddenly have HCM. These athletes typically have prodromal symptoms such as presyncope or syncope with or without exercise prior to the fatal event. A systolic murmur is often appreciated only in the standing position or with a Valsalva maneuver.
Congenital coronary artery anomalies are a frequent cause of sudden cardiac death. These athletes may or may not have symptoms of syncope or chest pain with exercise, making diagnosis difficult.
Athletes with aortic stenosis and mitral valve prolapse have abnormal auscultatory findings that should lead to the suspected diagnosis.
The preparticipation physical is critical for detecting cardiac conditions that may be life threatening.

Heat Illness

Epidemiology

Heat illness is the third most common cause of death in athletes.
Risk factors for heat illness include obesity, fever, recent respiratory or gastrointestinal (GI) viral illness, sickle cell trait, stimulants, supplements such as ephedrine, illicit drugs, alcohol, sleep deprivation, sunburn, and underconditioned athletes (9).
Heat illness usually occurs during unseasonable hot conditions at times of extreme exertion. A typical scenario is an obese football lineman wearing a football uniform and playing two-a-day practices during late summer tryouts in the Southeast United States.

Clinical Features

Heat cramps is a misnomer and should be termed exercise cramps. Muscle cramping is triggered by fatigue and can occur at any temperature.
Heat syncope is associated with an abrupt loss of consciousness in a heat-exposed athlete whose core temperature is normal or mildly elevated. The condition often occurs toward the completion of exercise due to reduced cardiac return and postural hypotension. Heat syncope usually occurs during the first few days of heat exposure before the body has been allowed to acclimatize.
Heat exhaustion is defined as the inability to continue to exercise in the heat since the cardiovascular system fails to respond to workload. The condition occurs at core or rectal temperatures between 100.4°F and 104°F. Symptoms of heat exhaustion can include muscle cramping, mild confusion, headache, dizziness, chills, nausea, and often collapse.
Heatstroke is exercise-associated collapse with thermoregulatory failure and central nervous system dysfunction. Heatstroke and mental status changes begin at temperatures in excess of 104°F. The athlete may or may not be sweating. The condition may result in a variety of life-threatening problems, such as rhabdomyolysis, renal failure, disseminated intravascular coagulopathy, liver failure, and brain injury.
The athlete with repeated heat illness requires a workup for a muscle enzyme deficiency.

Diagnosis and Treatment

A correct diagnosis is based on the history, physical examination, core body temperature, and differential including hyponatremia and cardiac conditions.
Treatment involves rapid cooling, moving to a cooler environment, removing clothing, tepid water spray, fans, and ice to the neck, groin, and axilla. Hydration should include both oral intake and intravenous fluids. Rehydration with sports drinks containing electrolytes is preferred over water. Athletes with core temperatures greater than 104°F should be considered for cold water immersion. Emergency medical services (EMS) should be contacted for athletes with heat exhaustion and heat stroke.

DIRECT INJURIES

Football

Epidemiology

Football has the highest number of catastrophic head and neck injuries per year for all high school and college sports (16).
From 1989 through 2002, the average number of quadriplegic events for high school and college football players was six per year (5).
From 1989 through 2002, there was an average of seven catastrophic head injuries per year for high school and college football participants (6). The incidence is dramatically higher at the high school level than at the college level (6).

Mechanisms

Spearing or tackling a player with the top of the head has been identified as a major cause of permanent cervical quadriplegia. When the neck is flexed 30 degrees, the cervical spine becomes straight, and the forces are transmitted directly to the spinal structures. In 1976, spearing was banned, and the rate of catastrophic cervical injuries dramatically dropped (24,25).
Cervical cord neurapraxia (CCN) is an acute, transient neurologic episode associated with sensory changes with or without motor weakness or complete paralysis in the arms, legs, or both (25). Complete recovery usually occurs within 10-15 minutes but may take up to 2 days. The pincer mechanism involves cord compression either through hyperflexion or hyperextension of the neck. Axial compression may also cause CCN via shear forces on the cervical spine (5).
An episode of CCN is not an absolute contraindication to return to football. It is unlikely that athletes who experience CCN are at risk for permanent neurologic sequelae with return to play. The overall risk of a recurrent CCN episode with return to football is approximately 50% and is correlated with the canal diameter size. The smaller the canal diameter, the greater is the risk of recurrence.
The majority of catastrophic head injuries are subdural hematomas (6). Forty percent of players have been reported to be playing with residual neurologic symptoms from a prior head injury at the time of the catastrophic injury (6).

Prevention

Banning spear tackling and teaching players to play “heads up” ball with no contact on the top of the helmet have dramatically reduced the incidence of permanent cervical quadriplegia. A recent change in the spear tackling rule to include intentional and unintentional spear tackling may further reduce the incidence of this injury.
The development of a safety standard for the football helmet by the National Operating Committee on Standards for Athletic Equipment (NOCSAE) has also been a significant factor in reducing catastrophic head injuries.
Careful surveillance for concussions and referral to medical personnel before return to play have reduced the incidence of catastrophic head injuries. Younger athletes often have a protracted recovery from concussion and may require delayed return to play compared to college and professional athletes.
Training medical personnel to understand on-field management of athletic head and neck injuries and guidelines for return to contact or collision sport after an injury will also help to reduce injuries.

Pole Vaulting

Epidemiology

Pole vaulting is a unique sport in that athletes often land from heights ranging from 10 to 20 ft. Prior to 2003, pole vaulting had one of the highest rates of direct, catastrophic injuries per 100,000 participants for all sports monitored by the NCCSIR (4).
The vast majority of catastrophic pole vaulting injuries are head injuries in male athletes. The overall incidence of catastrophic pole vault injuries is two per year, whereas the incidence of fatalities is one per year. Most injuries occurred at the high school level (4).

Mechanisms