An avulsion fracture is a bone fracture

Bone fracture

A bone fracture is a medical condition in which there is a break in the continuity of the bone...

 which occurs when a fragment of bone tears away from the main mass of bone as a result of physical trauma

Physical trauma

Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...

. This can occur at the ligament

Ligament

In anatomy, the term ligament is used to denote any of three types of structures. Most commonly, it refers to fibrous tissue that connects bones to other bones and is also known as articular ligament, articular larua, fibrous ligament, or true ligament.Ligament can also refer to:* Peritoneal...

 due to the application forces external to the body (such as a fall or pull) or at the tendon

Tendon

A tendon is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments and fasciae as they are all made of collagen except that ligaments join one bone to another bone, and fasciae connect muscles to other...

 due to a muscular contraction that is stronger than the forces holding the bone together. Generally muscular avulsion is prevented due to the neurological limitations placed on muscle contraction

Muscle contraction

Muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten, or remain the same...

s. Highly trained athletes can overcome this neurological inhibition of strength and produce a much greater force output capable of breaking or avulsing a bone.

If the fracture is small, it is usually sufficient to treat with rest and support bandage

Splint (medicine)

A splint is a device used for support or immobilization of limbs or of the spine.It can be used:* By the emergency medical services or by volunteer first responders, to immobilize a fractured limb before the transportation; it is then a temporary immobilization;* By allied health professionals such...

, but in more severe cases surgery

Surgery

Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...

 may be required. Ice may be used to relieve swelling

Swelling (medical)

In medical parlance, swelling is the transient enlargement or protuberance in the body and may include tumors. According to cause, it may be congenital, traumatic, inflammatory, neoplastic or miscellaneous....

.

For displaced avulsion fractures, they are best managed by either open reduction and internal fixation or closed reduction and pinning.

Dental avulsion

Traumatic

Dental trauma

Dental trauma refers to trauma to the face, mouth, and especially the teeth lips and periodontium. The study of dental trauma is called dental traumatology.- Types :* Tooth fractures**Enamel infraction**Enamel fracture**Enamel-dentine fracture...

 complete displacement of a tooth

Tooth

Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...

 from its socket in alveolar bone. It is a serious dental emergency

Dental emergency

A dental emergency is a type of medical emergency involving the teeth or gingiva. Pain involving these parts of the mouth, even when minor, can indicate a severe underlying problem that could worsen with time. It is important to contact a dentist as soon as possible for a professional evaluation...

 in which prompt management

Treatment of knocked-out (avulsed) teeth

The Treatment of knocked-out teeth consists of replantation, immediately if possible.Immediate replantation insures the best possible prognosis but is not always possible since more serious injuries may be present...

 (within 20–40 minutes of injury) affects the prognosis

Prognosis

Prognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...

 of the tooth.

Tuberosity avulsion

The tuberosity avulsion fracture (also known as pseduo-Jones fracture or dancer's fracture is a common fracture of the fifth metatarsal (little toe). This fracture is likely caused by the lateral band of the plantar aponeurosis (tendon). Most of these fractures are treated with a hard-soled shoe or walking cast. This is needed until the pain goes away and then the patient can return to normal activities. Healing is usually completed within eight weeks.

Dinosaurs

In 2001, Bruce Rothschild and other paleontologists published a study examining evidence for tendon avulsions in theropod dinosaurs. Among the dinosaurs studied, Avulsion

Avulsion

Avulsion in general refers to a tearing away. Specifically, it can refer to:* A type of amputation where the extremity is pulled off rather than cut off* Avulsion fracture* Avulsion injury, the removal of all the layers of skin from abrasion...

 injuries were only noted among Tyrannosaurus

Tyrannosaurus

Tyrannosaurus meaning "tyrant," and sauros meaning "lizard") is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex , commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, with a much wider range than other...

and Allosaurus

Allosaurus

Allosaurus is a genus of large theropod dinosaur that lived 155 to 150 million years ago during the late Jurassic period . The name Allosaurus means "different lizard". It is derived from the Greek /allos and /sauros...

. Scars from these sorts of injuries were limited to the humerus

Humerus

The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....

 and scapula

Scapula

In anatomy, the scapula , omo, or shoulder blade, is the bone that connects the humerus with the clavicle ....

. A divot on the humerus of Sue the T. rex was one such avulsion. The divot appears to be located at the origin of the deltoid

Deltoid

Deltoid can refer to:* The deltoid muscle, a muscle in the shoulder* Kite , also known as a deltoid, a type of quadrilateral* A deltoid curve, a three-sided hypocycloid* A leaf shape* The deltoid tuberosity, a part of the humerus...

 or teres major muscles. The localization in theropod scapulae as evidenced by the tendon avulsion in Sue suggests that theropods may have had a musculature more complex and functionally different than those of their descendants, the birds.