Sports injury


Sports injuries occur during participation in sports or exercise in general. Globally, around 40% of individuals engage in some form of regular exercise or organized sports, with upwards of 60% of US high school students participating in one or more sports. Sports injuries account for 15 - 20% of annual acute care visits with an incidence of 1.79 - 6.36 injuries per 1,000 hours of participation. Sports injuries can be broken down into the types of injuries, risk factors and prevention and the overall impact that injuries have on athletes.

Types of sport injury

The type of sports injury suffered varies greatly based on gender, age and sport. Nonetheless, those with the highest prevalence remain contusions, fractures and sprains, followed closely by wounds and overuse injuries. Also common, the possible severity of head and neck injuries are important to consider. It is also paramount to place emphasis on the specific injuries that are most commonly encountered by sports medicine specialists.

Soft tissue injuries

Soft tissue injuries can be divided into those that affect the connective tissue, ligaments, tendons, or muscles. Injuries affecting the integument or the skin, can be classified as contusions, abrasions, and lacerations. Contusions or bruises are the simplest and most common injuries and are usually a result of blunt force trauma. Severe contusions may involve deeper structures and can include nerve or vascular injury. Abrasions are superficial injuries to the skin that result from a shearing force and are no deeper than the most superficial tissue layer, the epidermis. Bleeding, when present, is minimal. Minor abrasions generally do not scar, but deeper abrasions generally bleed and may scar. Lacerations occur from blunt trauma and result in a puncture through the skin, leaving an open wound. Facial lacerations are the most variable of the soft tissue injuries that athletes can sustain. They can occur intraoral or extraoral, and vary from a superficial skin nick to a lip laceration, or involve significant vascular disruption or injury to collateral vital structures.
Another major set of soft tissue injuries are those that affect the tendons and ligaments involved in the function of weight bearing joints. Of the various ligament and tendon injuries sustained during sports, those that hold particular importance for sports medicine providers due to their high prevalence are described in the following table:

Table: Prevalence and Implications of Common Soft Tissue Sports Injuries

Bony Injuries

Types of hard tissue injuries can include dental and bone injuries and are less frequent than soft tissue injuries in sport, but are often more serious. Hard tissue injuries to teeth and bones can occur with contusions, such as Battle sign, which indicates basilar skull fracture, and so-called raccoon eyes, which indicate midface fractures. However, tooth fractures are the most common type of tooth injury, and can be categorized as crown infractions, enamel-only fracture, enamel-dentin fractures, and fractures that extend through the enamel and dentin into the pulp which is defined below.
  • Crown infractions are characterized by a disruption of the enamel prisms from a traumatic force, these injuries typically present as small cracks that affect only the enamel.
  • Enamel-only fractures are mild and often appear as roughness along the edge of the tooth crown. These injuries typically can go unnoticed by the athlete as they are usually not sensitive to the touch or temperature changes. Enamel-only fractures are not considered dental emergencies and immediate care is not needed.
  • Enamel-Dentin crown fractures typically present as a tooth fracture confined to enamel and dentin with loss of tooth structure, but not exposing the pulp. The athlete often will report sensitivity to air, cold or touch, but the athlete can return to play as tolerated and referral can be delayed up to 24 hours.
  • Enamel-Dentin-Pulp fractures extend through the enamel and dentin and into the pulp. If the pulp is vital, a focal spot of hemorrhage will be noticeable within the yellow dentin layer and the athlete may report acute pain. Referral to a trauma-ready dentist should occur as soon as possible.
In addition to tooth fractures, there are several types of bone fractures as well. These types being closed or simple, open or compound, greenstick, hairline, complicated, comminuted, avulsion, and compression. A complicated fracture is when the structures surrounding the fracture are injured, such as blood vessels, organs, nerves, etc.

Overuse injuries

Overuse injuries can be defined as injuries that result from a mechanism of repetitive and cumulative micro-trauma, that exceeds tissue repair capacity. Overuse injuries can be divided into three primary categories, tendinopathy, stress reaction and stress fractures, and Juvenile Osteochondritis Dissecans. Tendinopathy is the result of accumulative micro-trauma and degenerative changes to the tissue that can predispose to pain and even rupture with activity. Tendinopathy progresses in stages from tendinitis which is inflammatory driven, to later tendinosis which is primarily degenerative. The lack of inflammation in this later stage is in fact what hinders the bodies ability to heal the injury. Stress reaction and stress fractures occur due to accumulative trauma to bone that leads to a imbalance between bone cleavage and replacement leaving the bone prone to micro-damage and stress fractures.
A common cause for both these types of injuries are increase in training frequency and can be associated with poor technique, or other external factors like training on hard surfaces or long distance sports. Finally, the rapid changes in physical growth in children leave them prone to overuse injuries, especially Juvenile Osteochonditis Dissecans, in which the bone-cartilage interface is affected. This disease is driven primarily by repetitive micro-trauma sustained while training and can lead to pain in the affected joints. The disease predominately affects athletes undergoing rapid periods of growth, therefore as the athlete's bodies continues to mature, the disease tends to self-resolve.

Head and neck injuries

Sports-related head and neck injuries account for a large portion of athletic trauma, and the severity of these injuries account for an estimated 70% of sports-related mortality and 20% permanent disability. In the United States, approximately 1.6 to 3.8 million sports-related concussions occur annually, with contact sports such as football, hockey, and soccer carrying the highest incidence.
Concussion, the most common sports-related head injury, results from disrupted neurologic function due to significant mechanical forces imparted on the brain, plus resulting inflammation. Continuing research into sports related concussions has shown that repeat concussions can lead to a disorder called chronic traumatic encephalopathy, characterized by memory loss, lack of impulse control, amongst a myriad of mental health and movement disorders.
Sideline evaluation of concussed athletes includes symptom assessment, cognitive testing, and balance examination. Imaging, like CT-scan, is reserved for cases when intracranial hemorrhage, or bleeding into the brain, is suspected. Return-to-play protocols are designed to ensure a stepwise and timely recovery to prevent second-impact syndrome, a severe condition caused by swelling of the brain tissue.
Head and neck injuries commonly co-occur. When examining a patient with a neck injury, a physician will use specialized maneuvers in conjunction with a neurologic examination, to evaluate if the neck injury is causing compression or disruption of the nerve roots. Should a spinal cord injury be suspected, the athlete will be placed into spinal immobilization and sent for further testing. If an athlete with a head injury is unconscious, they are assumed to have a spinal cord injury and full spinal immobilization is required.
Several strategies, such as rule modifications and protective equipment have helped decrease the risk of head and neck injuries, especially in high contact sports like football and hockey. However, the effectiveness of such strategies has shown more efficacy for preventing concussions as compared to neck injuries. Given the severity of such injuries, the Concussion in Sport Group holds regular conferences to evaluate the literature on the topic and propose updated guidelines for prevention and management of these injuries.

Risk factors

Recent changes to load management for athletes and fear of overtraining led to a groundbreaking study by the International Olympic Committee in 2016, in which the committee hoped to identify risk factors predisposing athletes to overuse and risk of injury. The study performed a systematic review with an inclusion of 106 prior studies on load and injury risk. A major takeaway from the study was the analysis of how external versus internal factors predispose to injury and how these factors can be managed to avoid injury. Intrinsic or personal factors that could put an athlete at higher risk for injury could be gender. For example, female athletes are typically more prone to injuries such as ACL tears. There is approximately a 1.6-fold greater rate of ACL tears per athletic exposure in high school female athletes than in males of the same age range. Other intrinsic factors are age, weight, body composition, height, lack of flexibility or range of motion, coordination, balance, and endurance. In addition, biological factors such as pes planus, pes cavus, and valgus or varus knees can cause an athlete to have improper biomechanics and become predisposed to injury. There are also psychological factors that are included in intrinsic risk factors. Some psychological factors that could make certain individuals more subject to injury include personal stressors in their homes, school, or social life. There are also extrinsic risk factors that can affect an athlete's risk of injury. Some examples of extrinsic factors would be sport-specific protective equipment such as helmets, shoulder pads, mouth guards, and shin guards, and whether or not these pieces of equipment are fitted correctly to the individual athlete to ensure that they are each preventing injury as well as possible. Other extrinsic factors are the conditions of the sports setting such as rain, snow, and maintenance of the floor/field of playing surface.