The carpal bones are the eight small bones that make up the wrist (carpus) that connects the hand to the forearm. The term "carpus" and "carpal" is derived from the Latin carpus and the Greek καρπός (karpós), meaning "wrist". In human anatomy, the main role of the carpal bones is to articulate with the radial and ulnar heads to form a highly mobile condyloid joint, to provide attachments for thenar and hypothenar muscles, and to form part of the rigid carpal tunnel which allows the median nerve and tendons of the anterior forearm muscles to be transmitted to the hand and fingers.
The ulna or ulnal bone is a long bone found in the forearm that stretches from the elbow to the wrist, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of the forearm as the little finger. It runs parallel to the radius, the other long bone in the forearm. The ulna is longer and the radius is shorter, but the radius is thicker and the ulna is thinner. Therefore, the ulna is considered to be the smaller bone of the two bones in the lower arm. The corresponding bone in the lower leg is the fibula.
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 anatomical snuff box or snuffbox or foveola radialis is a triangular deepening on the radial, dorsal aspect of the hand—at the level of the carpal bones, specifically, the scaphoid and trapezium bones forming the floor. The name originates from the use of this surface for placing and then sniffing powdered tobacco, or "snuff." It is sometimes referred to by its French name tabatière.
The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is used to describe the entire appendage of the upper limb, but which in anatomy, technically, means only the region of the upper arm, whereas the lower "arm" is called the forearm. It is homologous to the region of the leg that lies between the knee and the ankle joints, the crus.
In human anatomy, the ulnar nerve is a nerve that runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest in the human body unprotected by muscle or bone, so injury is common. This nerve is directly connected to the little finger, and the adjacent half of the ring finger, innervating the palmar aspect of these fingers, including both front and back of the tips, perhaps as far back as the fingernail beds.
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 nut.
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 longer than the radius, but the radius is thicker. The radius is a long bone, prism-shaped and slightly curved longitudinally.
A distal radius fracture, also known as wrist fracture, is a break of the part of the radius bone which is close to the wrist. Symptoms include pain, bruising, and rapid-onset swelling. The ulna bone may also be broken.
A Smith's fracture, is a fracture of the distal radius.
The Galeazzi fracture is a fracture of the distal third of the radius with dislocation of the distal radioulnar joint. It classically involves an isolated fracture of the junction of the distal third and middle third of the radius with associated subluxation or dislocation of the distal radio-ulnar joint; the injury disrupts the forearm axis joint.
Madelung's deformity is usually characterized by malformed wrists and wrist bones and is often associated with Léri-Weill dyschondrosteosis. It can be bilateral or just in the one wrist. It has only been recognized within the past hundred years. Named after Otto Wilhelm Madelung (1846–1926), a German surgeon, who described it in detail, it was noted by others. Guillaume Dupuytren mentioned it in 1834, Auguste Nélaton in 1847, and Joseph-François Malgaigne in 1855.
The triangular fibrocartilage complex (TFCC) is formed by the triangular fibrocartilage discus (TFC), the radioulnar ligaments (RULs) and the ulnocarpal ligaments (UCLs).
A Barton's fracture is a type of wrist injury where there is a broken bone associated with a dislocated bone in the wrist, typically occurring after falling on top of a bent wrist. It is an intra-articular fracture of the distal radius with dislocation of the radiocarpal joint.
The Essex-Lopresti fracture is a fracture of the radial head of the forearm with concomitant dislocation of the distal radio-ulnar joint along with disruption of the thin interosseous membrane which holds them together. The injury is named after Peter Essex-Lopresti who described it in 1951.
The extrinsic extensor muscles of the hand are located in the back of the forearm and have long tendons connecting them to bones in the hand, where they exert their action. Extrinsic denotes their location outside the hand. Extensor denotes their action which is to extend, or open flat, joints in the hand. They include the extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor digitorum (ED), extensor digiti minimi (EDM), extensor carpi ulnaris (ECU), abductor pollicis longus (APL), extensor pollicis brevis (EPB), extensor pollicis longus (EPL), and extensor indicis (EI).
Radial dysplasia, also known as radial club hand or radial longitudinal deficiency, is a congenital difference occurring in a longitudinal direction resulting in radial deviation of the wrist and shortening of the forearm. It can occur in different ways, from a minor anomaly to complete absence of the radius, radial side of the carpal bones and thumb. Hypoplasia of the distal humerus may be present as well and can lead to stiffness of the elbow. Radial deviation of the wrist is caused by lack of support to the carpus, radial deviation may be reinforced if forearm muscles are functioning poorly or have abnormal insertions. Although radial longitudinal deficiency is often bilateral, the extent of involvement is most often asymmetric.
Wrist osteoarthritis is gradual loss of articular cartilage and hypertrophic bone changes (osteophytes). While in many joints this is part of normal aging (senescence), in the wrist osteoarthritis usually occurs over years to decades after scapholunate interosseous ligament rupture or an unhealed fracture of the scaphoid. Characteristic symptoms including pain, deformity and stiffness. Pain intensity and incapability are notably variable and do not correspond with arthritis severity on radiographs.
Nissen-Lie classification is a system of categorizing Colles' fractures. In the Nissen-Lie classification system there are seven types of fractures. The classification system was first published in 1939.
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.
