The carpal bones are the eight small bones that make up the wrist that connects the hand to the forearm. The term "carpus" is derived from the Latin carpus and the Greek καρπός (karpós), meaning "wrist". In human anatomy, the main role of the wrist is to facilitate effective positioning of the hand and powerful use of the extensors and flexors of the forearm, and the mobility of individual carpal bones increase the freedom of movements at the wrist.
In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; (2) the wrist joint or radiocarpal joint, the joint between the radius and the carpus and; (3) the anatomical region surrounding the carpus including the distal parts of the bones of the forearm and the proximal parts of the metacarpus or five metacarpal bones and the series of joints between these bones, thus referred to as wrist joints. This region also includes the carpal tunnel, the anatomical snuff box, bracelet lines, the flexor retinaculum, and the extensor retinaculum.
The ankle, or the talocrural region, or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The movements produced at this joint are dorsiflexion and plantarflexion of the foot. In common usage, the term ankle refers exclusively to the ankle region. In medical terminology, "ankle" can refer broadly to the region or specifically to the talocrural joint.
The scaphoid bone is one of the carpal bones of the wrist. It is situated between the hand and forearm on the thumb side of the wrist. It forms the radial border of the carpal tunnel. The scaphoid bone is the largest bone of the proximal row of wrist bones, its long axis being from above downward, lateralward, and forward. It is approximately the size and shape of a medium cashew.
The capitate bone is a bone in the human wrist found in the center of the carpal bone region, located at the distal end of the radius and ulna bones. It articulates with the third metacarpal bone and forms the third carpometacarpal joint. The capitate bone is the largest of the carpal bones in the human hand. It presents, above, a rounded portion or head, which is received into the concavity formed by the scaphoid and lunate bones; a constricted portion or neck; and below this, the body. The bone is also found in many other mammals, and is homologous with the "third distal carpal" of reptiles and amphibians.
The lunate bone is a carpal bone in the human hand. It is distinguished by its deep concavity and crescentic outline. It is situated in the center of the proximal row carpal bones, which lie between the ulna and radius and the hand. The lunate carpal bone is situated between the lateral scaphoid bone and medial triquetral bone.
The radius or radial bone is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna. The ulna is usually slightly longer than the radius, but the radius is thicker. Therefore the radius is considered to be the larger of the two. It is a long bone, prism-shaped and slightly curved longitudinally.
Cleidocranial dysostosis (CCD), also called cleidocranial dysplasia, is a birth defect that mostly affects the bones and teeth. The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close together. The front of the skull often does not close until later, and those affected are often shorter than average. Other symptoms may include a prominent forehead, wide set eyes, abnormal teeth, and a flat nose. Symptoms vary among people; however, intelligence is typically unaffected.
In the sphenoid bone, the anterior boundary of the sella turcica is completed by two small eminences, one on either side, called the anterior clinoid processes, while the posterior boundary is formed by a square-shaped plate of bone, the dorsum sellæ, ending at its superior angles in two tubercles, the posterior clinoid processes, the size and form of which vary considerably in different individuals. The posterior clinoid processes deepen the sella turcica, and give attachment to the tentorium cerebelli.
The midcarpal joint is formed by the scaphoid, lunate, and triquetral bones in the proximal row, and the trapezium, trapezoid, capitate, and hamate bones in the distal row. The distal pole of the scaphoid articulates with two trapezial bones as a gliding type of joint. The proximal end of the scaphoid combines with the lunate and triquetrum to form a deep concavity that articulates with the convexity of the combined capitate and hamate in a form of diarthrodial, almost condyloid joint.
The pyriform sinus is a small recess on either side of the laryngeal inlet. It is bounded medially by the aryepiglottic fold, and laterally by the thyroid cartilage and thyrohyoid membrane. The fossae are involved in speech.
A Chance fracture is a type of vertebral fracture that results from excessive flexion of the spine. Symptoms may include abdominal bruising, or less commonly paralysis of the legs. In around half of cases there is an associated abdominal injury such as a splenic rupture, small bowel injury, pancreatic injury, or mesenteric tear. Injury to the bowel may not be apparent on the first day.
The scapholunate ligament is a ligament of the wrist.
A syndesmophyte is a bony growth originating inside a ligament, commonly seen in the ligaments of the spine, specifically the ligaments in the intervertebral joints leading to fusion of vertebrae. Syndesmophytes are pathologically similar to osteophytes. Ankylosing spondylitis patients are particularly prone to developing syndesmophytes. They are also commonly seen in patients who have had back surgery or other chronic stresses on the ligaments of their spine. Syndesmophytes indicate spine degeneration, similar to osteophytes of spine; however, they bridge across the joint as compared to osteophytes which are non-bridging.
Wrist osteoarthritis is a group of mechanical abnormalities resulting in joint destruction, which can occur in the wrist. These abnormalities include degeneration of cartilage and hypertrophic bone changes, which can lead to pain, swelling and loss of function. Osteoarthritis of the wrist is one of the most common conditions seen by hand surgeons.
Dorsal intercalated segment instability (DISI) is a deformity of the wrist where the lunate bone angulates to the dorsal side of the hand.
There are a number of ways to classify distal radius fractures. Classifications systems are devised to describe patterns of injury which will behave in predictable ways, to distinguish between conditions which have different outcomes or which need different treatments. Most wrist fracture systems have failed to accomplish any of these goals and there is no consensus about the most useful one.
Wilkinson's syndrome is a radiographic term which describes a unilaterally enlarged pedicle opposite a contralateral pars defect. The enlarged pedicle may due to stress hypertrophy, and changes may extend into the adjacent lamina and transverse processes.
Srb's anomaly is the clinical condition describing synostosis, or fusion, between the first and second ribs. It may be either a partial or complete fusion between the two ribs to create an entirely indistinguishable new rib.
Carpal coalition is the abnormal fusion of two or more carpal bones when they fail to segment during intrauterine development. First described by Eduard Sandifort in 1779, carpal coalitions are often an isolated issue which connect two carpal bones in the same row of the wrist. These issues are congenital and occur at various rates throughout the population.
