Sports causing SCI

1. Sports causing SCI • Approximately 8.7% of all new cases of spinal cord injuries in the United States are related to sports . • Athletic injuries are third only to motor vehicle accidents and violence as the most common cause of spinal cord injury in people aged 30 years or younger . • A 3-year nationwide survey of all sports in Japan revealed a spinal injury incidence of 1.95 per million per year, with a mean age at injury of 28.5 years, and with 88% occurring in males.

2. Catastrophic Spinal Cord Injuries • are much more likely to result from a cervical spinal injury than thoracic or lumbar trauma. • Historically, sports at greatest risk for catastrophic spinal injuries have been football, ice hockey, wrestling, diving, skiing, snowboarding, rugby, cheerleading, and baseball.

3. Spinal Injuries • The most common spine injuries in athletics can be carefully managed with nonoperative treatment. • More serious spinal injuries, however, may lead to death, permanent disability, and extreme morbidity. • The most common mechanism for injury leading to quadriplegia is an axial compressive force applied to the top of the head while the neck is slightly flexed, leading to loss of the protective cervical lordosis and alignment of the cervical vertebra.

4. Information on Catastrophic Injuries in Sports • recorded by the National Center for Catastrophic Sports Injury Research (NCCSIR), the National Spinal Cord Injury Statistical Center, the United States Consumer Product Safety Commission (CPSC), and other organizations • The NCCSIR defines a catastrophic sports injury as any severe spinal, spinal cord, or cerebral injury incurred during participation in any school- or college-sponsored sport. • These injuries are further subclassified into direct and indirect, and serious, nonfatal, and fatal for epidemiologic purposes .

5. Common Athletic Injuries to the Spine • include strains, muscle spasms, compression fractures, avulsion fractures, and disc herniations, with strains being the most common. • Strains can be caused by any low-grade force to the spine, including the sudden extension-flexion mechanism associated with whiplash injuries. • These athletes typically present with paravertebral muscle spasm, limited range of motion, and a normal neurologic examination. • The loss of normal cervical lordosis or thoracic kyphosis may be seen on plain radiographs. • Treatment involves conservative management with relative rest, anti-inflammatories (NSAIDs), muscle relaxants, and physical therapy.

6. Compression Fractures • Although compression fractures can occur anywhere along the course of the vertebral column, cervical spine compression fractures typically occur at the lower levels of C4 to C7. • Radiologic evaluation with anterior-posterior, lateral, and flexion-extension radiographs are helpful in excluding serious injuries. • Occasionally, when radiolographic negative evaluations are negative, CT or MRI may be necessary to further characterize an injury when the clinician has a high suspicion for cervical injury.

7. Compression Fractures • Isolated compression fractures with less than 25% anterior compression can be conservatively managed with a cervical orthosis. • Compression fractures with greater than 50% anterior compression are frequently associated with posterior ligamentous disruption, are usually unstable, and may require surgical fixation. • A CT scan is helpful in evaluating fractures of the posterior vertebra and the vertebral elements that, if injured, may compromise spinal stability.

8. Shoveler's Fractures • Cervical spinous process avulsion injuries, known as clay shoveler's fractures, usually occur in football players and power lifters at the C7 level. • The most widely accepted theory for the mechanism of injury in clay shoveler's fracture is a forceful flexion of the cervical spine, or forceful contraction of the trapezius and rhomboid muscles. • These avulsion fractures are quite stable and can usually be treated with cervical orthosis and other symptomatic measures such as pain medications and ice.

9. Catastrophic cervical spine injuries • include unstable fractures or dislocations, cervical cord neuropraxia (CCN or transient quadriplegia), and intervertebral disc herniations. • The most frequent causes of catastrophic cervical spine injury, unstable fractures and dislocations, often result in permanent neurologic sequalae and usually occur in the lower cervical spine. • In the lower cervical spine, the spinal cord occupies close to 75% of the canal's cross-sectional area as compared with less than half at the level of the atlas • .

10. Cervical Injuries resulting in Quadriplegia • typically occur following application of an axial force to the top of the head while the neck is slightly flexed . • The neutrally positioned neck has a protective lordotic curve, and most of the energy is dissipated by the paravertebral muscles and the intervertebral discs during an impact. • When the neck is forward flexed about 30°, the cervical spine straightens, allowing the forces to be transmitted to the aligned cervical column.

11. Cervical Injuries resulting in Quadriplegia • Once maximum compressive forces are reached, the spine fails. This occurs in either a flexion (flexion teardrop) or pure compression (burst fracture) mode with a resultant fracture, dislocation, or subluxation. • This injury sequence may cause vertebral fragments or the intervertebral disc to retropulse into the spinal canal causing spinal cord damage.

12. Cervical Fracture/DislocationsStretch Test • An alternative to the flexion/extension radiographs is the use of controlled axial-traction lateral radiographs, also referred to by White as the "stretch test.” • The stretch test is performed after a standard nontraction lateral C-spine radiograph has been obtained and examined to rule out obvious instability or subluxation. • In the stretch test, the patient is placed supine with the head supported on a roller platform to reduce friction. • The head is placed in a traction rig with either Garner-Wells tongs or a head halter, and incremental 10-lb loads of weight are applied. • The 10-lb weights are added in the presence of the treating physician. The maximum weight allowed is equivalent to 33% of the patient's body weight.

13. Cervical Fracture/DislocationsStretch Test • The physician performs serial neurologic assessments of the patient with each addition of weight. • A lateral C-spine radiograph is obtained with each addition of weight. • The time interval between weight increments should be at least 5 minutes. • The stretch test is considered positive for instability if one of the following situations occurs: (1) the patient sustains a change in neurologic function, (2) on comparison with the pretraction radiograph, there is greater than 1.7 mm of interspace separation of the anterior or posterior elements, or (3) there is greater than 7.5° change in the angle between vertebrae.

14. CNN • CCN is an acute, usually transient neurologic injury, associated with sensory changes and possible weakness or paralysis in at least two extremities. • Despite these findings, the cervical spine bony elements are usually uninjured and the patient is pain-free at the time of injury, with full range of motion. • CCN is classified based on the neurologic deficit, duration of neurologic symptoms, and the pattern of injury . • Injury grading is based on the duration of symptoms: Grade I, less than 15 minutes; Grade II, 15 minutes to 24 hours; and Grade III, longer than 24 hours.

15. CNN • The pattern of injury is classified as quadriplegia, upper only, lower only, or hemiplegia. A prevalence of seven per 10,000 football participants has been previously estimated. • Symptoms typically resolve within 10 to 15 minutes. Cervical stenosis is theorized to be the primary predisposing factor to CCN. • Previously, the postulated mechanism of injury was either a hyperflexion or hyperextension of the neck causing a pincer-type spinal cord compression injury ; however, new data have revealed that no one position particularly predisposes to CCN, and that various mechanisms, including axial forces, can be causative .

16. CCN • An episode of CCN is not an absolute contraindication to return to contact sports. • It is unlikely that athletes who have had previous CCN injuries are at increased risk for permanent quadriplegia with further contact activities. • Rather, poor technique using the top of the head for tackling is the primary risk factor for quadriplegia. • Currently, there are no reports of any previously CCN-injured athlete sustaining a quadriplegic event after returning to contact sports; however, because the number of athletes returning to play after a CCN injury is low, no definitive conclusions can be made. • Although complete resolution of symptoms is the rule with CCN, mild permanent neurologic deficits have been rarely reported .

17. CCN • Athletes who sustain a CCN injury need to be counseled on the known and potential risks of injury with return to contact sports. • Specifically, there is a 50% overall risk of a recurrent CCN episode with return to football, which varies individually based on the canal diameter size—the smaller the canal diameter, the greater the risk of recurrence . • Athletes who have any ligamentous instability, neurologic symptoms lasting longer than 36 hours, recurrent episodes, or MRI evidence of cord defect, cord edema, or minimal functional reserve should be excluded from return to contact sports .

18. CNN • Currently only athletes who have a previous history of CCN should undergo screening for spinal cord stenosis. • Radiation risk and cost make screening all athletes prohibitive. • During the pre-participation physical examination (PPEs) providers should screen all athletes for any previous history of neck injury because this may obviate further questioning and screening.

19. The Pavlov-TorgRatio • for assessing cervical spinal stenosis involves measuring the cervical canal diameter and dividing it by the anteroposterior width of the vertebral body. • A ratio of less than 0.8 potentially indicates significant cervical stenosis; however, this is a poor screening tool, because many football players have normal canal dimensions but large vertebral bodies, artificially decreasing this ratio below 0.8 . • A functional spinal stenosis may be a more accurate way of looking for athletes at risk of CCN. • This is seen when there is a loss of the normal amount of cerebrospinal fluid around the spinal cord on MRI or CT myelography .

20. Sport-specific considerations for Catastrophic Spine Injuries -Football • Because of large participation numbers and a high incidence of catastrophic injuries, football is associated with the highest number of severe cervical injuries per year for any high school or collegiate sport. • Though head-related fatalities declined in the early 1970s as a result of better protective helmets, the number of cervical quadriplegia cases increased, likely because tacklers began hitting opponents using the crown of the head because of decreased fear of head injury. • Torgand colleagues were instrumental in reducing the rate of quadriplegia as a result of cervical injury once they demonstrated that spearing, or tackling another player using the top of the head, was the major cause of permanent cervical quadriplegia .

21. Football • Spear tackling injuries typically occur to defensive players, especially defensive backs, as they attempt to tackle an offensive player. • Special team players are especially susceptible because the speed at the time of collision is extremely high . • After intentional spearing was banned in 1976, the rate of catastrophic cervical injuries dropped 80% from 1976 to 1987. • This decline continued, and the incidence of quadriplegic injuries at the high school and college levels remained stable in the 1990s and early 2000s at 0.52 per 100,000 participants per year . • In a recent review of over 500,000 high school football injuries of the 2005–2006 season, 4.1% of all injuries involved the neck or cervical spine, further defining this at-risk population .

22. Ice Hockey • In one study of injury data from the 2001–2002 NCAA ice hockey season, 9% of all hockey injuries occurred to the spine . • When compared with other sports, the overall number of catastrophic injuries in high school and college ice hockey players is lower, but the incidence is comparatively higher. • These injuries generally occur in the cervical region, especially at the C-5 through C-7 levels .

23. Ice Hockey • Checking from behind is the most common cause of injury; the player being checked is looking down and not anticipating the check, which sends him hurtling crown first into the boards, axially loading the cervical spine . • Impact velocities as slow as 1.8 m/s provide 75% of the axial compressive load necessary for cervical spine failure • By comparison, skating speeds exceed 12 m/s and the speed of a sliding skater can be as high as 6.7 m/s, with either situation able to create the force necessary to cause cervical axial load compression failure in a vulnerable player.

24. Wrestling • The vast majority of catastrophic injuries in wrestlers are caused by cervical fractures or major cervical ligament injuries, and the annual catastrophic injury rate is about 1 per 100,000 high school and collegiate wrestlers. • Most injuries occur during match competitions in the low and middle weight classes . • The most common wrestling maneuver associated with these injuries was the takedown of a standing opponent in a defensive position .

25. Wrestlers are typically injured by one of Three mechanisms: • the wrestler is thrown to the mat while both arms are being held, preventing him from being able to protect himself and resulting in the wrestler landing on his head; • the wrestler is landed upon by the full weight of the top wrestler midway through an attempted roll; • or the wrestler sustains an axial compression force to the cervical spine while attempting to “shoot” on an opponent as a result of hitting heads, a knee, or another hard surface.

26. Most swimming-associated Catastrophic Spinal Injuries • occur with race diving into the shallow end of a pool . • This occurs when a swimmer sustains a cervical axial compression injury after diving head-first into the shallow end of a pool . • The national high school and collegiate associations have implemented rules to prevent injuries during the racing dive. • At the high school level, swimmers must start the race in the water if the water depth at the starting end is less than 3.5 feet. • If the water depth is 3.5 feet to less than 4 feet at the starting end, the swimmer may start in the water or from the deck.

27. Swimming • If the water depth at the starting end is 4 feet or more, the swimmer may start from a platform up to 30 inches above the water surface. • College rules require a minimum water depth of 4 feet at the starting end of the pool. • During practice sessions where platforms may not be available, swimmers are advised to only dive into the deep end of the pool or to jump into the water feet first.

28. Swimming • Many recreational diving injuries go unreported, hampering attempts at improved awareness and water safety. In a retrospective review of traumatic spinal cord injuries presenting to a trauma center in Germany, 7.7% were caused by diving accidents . • Ninety-seven percent of the injured patients were male. Inadequate supervision, alcohol use, shallow water, and inexperienced divers are all risk factors for injury . • Preventive strategies for swimmers include not diving head-first into shallow or unknown waters, removing the high board in favor of a water slide, maintaining adequate supervision of inexperienced swimmers and divers, and avoiding alcohol and other judgment-affecting substances to reduce the incidence of spinal cord injuries.

29. Downhill skiing/snowboarding • The incidence of severe spinal cord injury is 0.01 injuries per 1,000 skier-days . • These injuries are evenly distributed at all spinal levels . • These injuries have been increasing among skiers during the last 2 decades, especially in young males. • They occur during falls as a result of poorly groomed slopes, equipment failures, unfavorable weather conditions, overcrowding, skier error, or loss of control. • Although spinal injuries are not the etiology of all skiing fatalities, they have been well-documented as a significant cause of death in skiers .

30. Downhill skiing/snowboarding • Spinal injuries in snowboarders have been reported to be three- to fourfold higher than in skiing, and this ratio seems to be increasing as snowboarding grows in popularity. • Snowboard injuries typically occur in two basic populations: inexperienced snowboarders having falls, and expert and intermediate snowboarders involved in jumping accidents . • Snowboard jumping causes up to 80% of spinal injuries, which usually affect the thoracolumbar region in these athletes .

31. Cheerleading • Recently cheerleading has evolved from a motivational support role into an activity demanding high levels of skill, athleticism, and complex gymnastic maneuvers. • Though the incidence of cheerleading injuries is relatively low compared with other sports, it carries a high risk of catastrophic injury. • Cheerleaders have accounted for more than half of the catastrophic injuries that occurred in high school and college female athletes from 1982 to 2005 [4]. • College athletes are five times more likely than high school athletes to sustain a catastrophic injury. • This is likely because of the increased complexity of stunts at the college level . • In 2000 a total of 1814 neck injuries, including 76 cervical fractures, in cheerleaders who presented to emergency departments.

32. Cheerleading • Pyramid formations with the cheerleader on the top and the basket toss, in which a cheerleader is thrown into the air to heights of 6 to 20 feet and then caught before landing on the ground, are the most common stunts to result in catastrophic injury . • Other less common mechanisms of injury involve advanced floor tumbling routines, participating on a wet surface, or performing a mount. • The vast majority of injuries occur when an athlete lands on a hard surface.

33. Baseball • Although baseball has a low noncatastrophic injury rate, it has a relatively high catastrophic injury incidence compared with other sports, with 1.95 catastrophic injuries per year, or 0.43 injuries per 100,000 participants . • Severe head injuries are more common than cervical spine injuries. • Catastrophic spine injuries in baseball most commonly occur as a result of a collision between a base runner and a fielder, typically the catcher . • A typical mechanism is when a base runner dives head-first into a catcher, sustaining an axial compression cervical injury .

34. Baseball • Although rarely enforced, baseball rules state that the fielder has the right of way to the base path and that the runner should avoid the fielder, especially when it involves the catcher at home plate. • Because the speed of head-first sliding has not been shown to be statistically different from feet-first sliding and the risk of catastrophic injury is high with head-first sliding, the rules regarding the head-first slide needs to be reassessed at the high school and collegiate levels . • In Little League Baseball, head-first sliding is never allowed. • Preventive measures include enforcing the rules regarding base path right of way, and instituting or enforcing feet-first sliding only in all baseball below the professional leagues.

35. Conclusion • The incidence of catastrophic cervical injuries in sports has significantly decreased over the last 30 years. • This decrease is the result of monumental rule changes, such as the ban on spearing in American football, better coaching on contact and tackling techniques, the presence and instruction of athletic trainers at all levels of play, and the improvement in protective gear including helmets and shoulder pads. • Unfortunately, when catastrophic neurologic injuries do occur, they are permanent and life changing.