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.
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.
Arthrogryposis (AMC) describes congenital joint contracture in two or more areas of the body. It derives its name from Greek, literally meaning 'curving of joints'.
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.
Finkelstein's test is a test used to diagnose de Quervain's tenosynovitis in people who have wrist pain.
Aplasia is a birth defect where an organ or tissue is wholly or largely absent. It is caused by a defect in a developmental process.
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.
Duane-radial ray syndrome, also known as Okihiro Syndrome, is a rare autosomal dominant disorder that primarily affects the eyes and causes abnormalities of bones in the arms and hands. This disorder is considered to be a SALL4-related disorder due to the SALL4 gene mutations leading to these abnormalities. It is diagnosed by clinical findings on a physical exam as well as genetic testing and imaging. After being diagnosed, there are other evaluations that one may go through in order to determine the extent of the disease. There are various treatments for the symptoms of this disorder.
Dysmelia is a congenital disorder of a limb resulting from a disturbance in embryonic development.
The elbow is the region between the upper arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa, and the lateral and the medial epicondyles of the humerus. The elbow joint is a hinge joint between the arm and the forearm; more specifically between the humerus in the upper arm and the radius and ulna in the forearm which allows the forearm and hand to be moved towards and away from the body. The term elbow is specifically used for humans and other primates, and in other vertebrates forelimb plus joint is used.
Radial aplasia is a congenital defect which affects the formation of the radius bone in the arm. The radius is the lateral bone which connects the humerus of the upper arm to the wrist via articulation with the carpal bones. A child born with this condition has either a short or absent radius bone in one or both of his or her arms. Radial aplasia also results in the thumb being either partly formed or completely absent from the hand, which can result in difficulties performing activities of daily living. Radial aplasia is connected with the condition VACTERL association, under the 'L' for limb malformations.
Oligodactyly is the presence of fewer than five fingers or toes on a hand or foot.
Thumb hypoplasia is a spectrum of congenital abnormalities of the thumb varying from small defects to complete absence of the thumb. It can be isolated, when only the thumb is affected, and in 60% of the cases it is associated with radial dysplasia. Radial dysplasia is the condition in which the forearm bone and the soft tissues on the thumb side are underdeveloped or absent.
Ectrodactyly, split hand, or cleft hand involves the deficiency or absence of one or more central digits of the hand or foot and is also known as split hand/split foot malformation (SHFM). The hands and feet of people with ectrodactyly (ectrodactyls) are often described as "claw-like" and may include only the thumb and one finger with similar abnormalities of the feet.
Hemimelia is a birth defect consisting in unilateral or bilateral underdevelopment of the distal part of the lower or upper limb. The affected bone may be shortened or not develop at all.
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.
Ectrodactyly with tibia aplasia/hypoplasia also known as cleft hand absent tibia is a very rare limb malformation syndrome which is characterized by ectrodactyly, and aplasia/hypoplasia of the tibia bone. Additional findings include cup-shaped ears, pre-postaxial polydactyly, and hypoplasia of the big toes, femur, patella, and ulnae bone. It is inherited as an autosomal dominant trait with reduced penetrance.
Van Den Berghe Dequeker syndrome, also known as ulnar hypoplasia-split foot syndrome is a very rare congenital limb malformation syndrome which is characterized by severe ulnar hypoplasia, absence of the index to pinky finger in both hands, and split-foot.
