In human anatomy, the wrist is variously defined as 1) carpus bone or carpal bone, an eight-bone complex that forms the proximal skeletal segment of the hand; (2) wrist joints or radiocarpal joints , the joints between the radius and the carpus and (3) the anatomic areas around the carpus including the distal portion of the forearm bone and the proximal portion from metacarpus or five metacarpal bones and a series of joints between these bones, which are referred to as wrist joints . This area also includes carpal tunnel, anatomical tobacco box, bracelet line, flexor retinaculum, and extensor retinaculum.
As a consequence of these different definitions, the fracture to the carpal bone is called a carpal fracture, while fractures like fracture distal fractures are often considered broken bones into the wrist.
Video Wrist
Structure
The distal radioular joint is a pivot joint located between the forearm, the fingers and the ulna. Formed by ulna heads and ulnaris notch radius, these joints are separated from radiocarpal joints by articular discs located between the radius and ulcer styloid processes. The joints are weak and extend from the inferior sacciform to the ulnar shaft. Together with the proximal radioular joints, distal radioulnar joints allow pronation and supineation.
The radiocarpal joint or wrist joint is an ellipsoid joint formed by the radius and proximal articular discs and the proximal row of the distal carpal bone. The carpal bone on the ulnar side only makes intermittent contact with the proximal side - triquetrum only makes contact during the ulnar kidnapping. Capsule, loose and unbranched, thin on the dorsal side and can contain synovial folds. The capsule is continuous with the midcarpal joint and is reinforced by many ligaments, including the palmar and dorsal radiocarpal ligaments, and the ulnar and radial collateral ligaments.
The parts that make up the radiocarpal joint are the lower end of the radius and below the surface of the above articular disc; and scaphoid bone, crescent moon, and triquetral below. The articular surface of the radius and below the surface of the articular disk forms along a transverse, transverse, ellipse surface, the receptor cavity. The superior articular surface of the scaphoid, crescent moon, and triquetrum forms a smooth convex surface, condyles, which are received into the hollow.
Tulang Carpal dari tangan:
- Proksimal: A = Scaphoid, B = Lunate, C = Triquetrum, D = Pisiform
- Distal: E = Trapezium, F = Trapezoid, G = Capitate, H = Hamate
In the right hand a total of 13 bones form part of the wrist: eight carpal bones - scaphoid, crescent moon, triquetral, pisiform, trapezium, trapezoid, capitation, and hamate - and five metacarpal bones - the first, second, third, fourth, and fifth.
The midcarpal joint is an S-shaped joint space that separates the proximal and distal carpal bones. The interarpal joint, between the bones of each row, is strengthened by carpal mummifying and ligaments of the lamamate and ligaments of intersumal, interosseous, and dorsal ligaments. Some degree of mobility may be between the bones of the proximal line while the bones from the distal row are connected to each other and to the metacarpal bone - to the carpometacarpal joint - by the powerful ligaments - pisometacarpal and palmar and dorsal carpometacarpal ligaments - which create functional entities of bone- this bone. In addition, the joints between metacarpal bone bases - intermetakpalal articulation reinforced by dorsal intermetarparpal, interosseous, and palmar ligaments.
Articulation
The radiocarpal, interakaral, midcarpal, carpometacarpal, and intermetacarpal joints often communicate with each other through a common synovial cavity.
Articular Surfaces
It has two articular surfaces named, the proximal and distal articular surfaces. The proximal articular surface consists of the lower end of the radius and the triangular articular disc of the inferior ulnar-radio joint. On the other hand, the distal articular surface consists of the proximal surface of the scaphoid bone, triquetral and crescent.
Maps Wrist
Function
Movement
Extrinsic hand muscles are located in the forearms where their abdomen forms a proximal fleshy roundness. When contracted, most of the tendons of these muscles are prevented from standing like tight bowstring around the wrist by passing under the flexor retinaculum on the palmar side and the extensor retinaculum on the back side. On the palmar side the carpal bones form a carpal tunnel traversed by some flexor tendons through a tendon sheath that allows it to slide back and forth through a narrow alley (see carpal tunnel syndrome).
Starting from the middle position of the hand, the movement allowed on the wrist is (muscle in order of importance):
- Marginal movements: radial deviation (kidnapping, movement toward the thumb) and ulnar deviation (adduction, movement toward the little finger). These movements occur around the dorsopalmar axis (back to front) at the radiocarpal and midcarpal joints that pass through the bruised bone.
- Radial abduction: extensor carpi radialis longus, abductor pollicis longus, extensor pollicis longus, flexor carpi radialis, flexor pollicis longus
- Ulnar adduction: extensor carpi ulnaris, flexor carpi ulnar, extensor digitorum, extensor digiti minimi
- Movement on the plane of the hand: flexion (palmar flexion, inclined towards the palm of the hand) and extension (dorsiflexion, tilted toward the back of the hand). These movements occur through the transverse axis passing through the capitation bone. Palmar flexion is the most powerful of these movements because the flexor, especially the flexor of the finger, is much stronger than the extensor.
-
- Extensions: extensor digitorum, extender carpi radialis longus, extender carpi radialis brevis, extensor indicis, extensor pollicis longus, extensor digiti minimi, extensor carpi ulnaris
- Palmar flexion: flexor digitorum superfisialis, flexor digitorum profundus, flexor carpi ulnar, flexor pollicis longus, flexor carpi radialis, abductor pollicis longus
- Medium or combined motion
However, movements in the wrist can not be described appropriately without including motion in the distal radioulnar joints where supine rotary action and pronation occur and these joints are therefore usually considered to be part of the wrist.
Clinical interests
Wrist pain has a number of causes, including carpal tunnel syndrome and osteoarthritis. Tests like the Phalen test involve palmarfleksion on the wrist.
The hand may deviate on the wrist in some conditions, such as rheumatoid arthritis.
Bone ossification around the wrist is one of the indicators used to measure bone age.
The term 'wrist fracture' can be used to refer to distal radius fractures.
History
Etymology
Source of the article : Wikipedia
0 Comments