The wrist joint is the connection of the forearm to the hand. The wrist joint is formed by the radius and the bones of the wrist — the navicular, lunate, and trihedral (Fig.). Movement is possible in it: flexion and extension, adduction and abduction of the hand. The capsule of the wrist joint with its upper edge is attached to the radius and triangular cartilage, the lower - to the first row of the bones of the wrist. On the palmar surface of the wrist joint there are two synovial sheaths , through which the flexor tendons of the fingers, arranged in four layers, pass. The extensor tendons at the level of the wrist joint are located in the synovial sheaths and are located on the dorsum of the wrist joint in two layers. The blood supply to the palmar side of the wrist joint comes from the radial and ulnar arteries, each of which is accompanied by two veins. The back surface of the wrist joint receives blood from the dorsal branch of the radial artery. The joint is innervated by the branches of the ulnar and median nerves. Lymphatic drainage is carried out by deep lymphatic vessels in the axillary lymph nodes.
Cut the right hand:
1 - interosseous membrane;
2 - radius;
3 - wrist joint;
4 - navicular bone;
5 and 12 - lateral radial and ulnar ligaments of the wrist;
6 and 7 - small and large trapezoid bones;
8 - metacarpal bones;
9 - capitate bone;
10 - hooked bone;
11 - triangular bone;
13 - articular disc;
14 - ulna bone.
Damage . Bruises of the wrist joint are relatively rare. Stretching occurs with a sharp excessive flexion, extension, abduction and adduction of the hand and is accompanied by tearing of the ligaments. At the same time on a limited area of the wrist joint is determined by swelling and pain when moving. The diagnosis of stretching is made only after exclusion of a fracture of the radius and navicular bones. Treatment: cold, pressure bandage or back plaster splint on the hand and forearm for 3-6 days.
Dislocations in the wrist joint are extremely rare, dislocations of the lunate or navicular bone are more common. First aid for sprains is reduced to the imposition of an immobilizing bandage type kerchief. Treatment - reduction of dislocation - under anesthesia produces a doctor; after reposition, they apply a plaster cast for 3 weeks. Then appoint thermal procedures, therapeutic gymnastics.
Of intra-articular fractures of the wrist joint, fractures of the scaphoid and lunate bones are more common. A fracture of the navicular bone occurs when falling on an outstretched arm, it can be combined with a fracture of the radial bone in a typical place (see Forearm ). Symptoms: swelling, pain and difficulty moving in the wrist. The diagnosis is clarified radiographically. Treatment: the imposition of gypsum splints for 8-10 weeks. Subsequently, to develop the function of the joint - remedial gymnastics , thermal procedures.
Wounds of the wrist joint (usually gunshot) in peacetime are rarely observed. First aid is the imposition of an aseptic dressing, immobilization of the limb, the introduction of tetanus toxoid in the arm. In the surgical hospital - primary treatment of wounds , stop bleeding, removal of bone fragments, etc .; then a plaster cast is applied from the metacarpophalangeal joint to the middle third of the shoulder in the functionally advantageous position of the elbow and wrist joint. Primary treatment of open injuries of the wrist joint prevents the development of further purulent complications in the wrist joint, as well as (in later periods) osteomyelitis.Go
Diseases . Arthritis of the wrist joint occurs primarily as a complication of purulent tenobursitis as a result of penetrating wounds or tuberculosis infection (see Arthritis, Tuberculosis of bones and joints ).
The radiocarpal joint (articulatio radiocarpea) connects the forearm to the hand. Radial bone and proximal wrist bones - navicular (os scaphoideum), semilunar (os lunatum) and trihedral (os triquetrum) participate in this joint. Between the first and second row of carpal bones, there is an inter-carpal joint, which, together with the wrist joint, forms a functionally interconnected hand joint. The articular cavity is formed by the carpal articular surface of the radial bone (facies articularis carpea radii), which connects to the navicular and semilunar bones, as well as the triangular connective tissue cartilage (discus articularis), performing a gap between the shorter than the radius, the ulnar bone, and the articular surface for triangular bone. The distal ends of the radial and ulnar bones are connected by a joint (art. Radioulnaris distalis).
The capsule of the wrist joint is very thin. Its upper edge is attached to the edge of the articular surface of the radial bone and triangular cartilage, the lower edge is attached to the edge of the articular surfaces of the first row of wrist bones. The joint capsule is reinforced laterally by the radial lateral ligament of the wrist (lig. Collaterale carpi radiale) and the ulnar lateral ligament of the wrist (lig. Collaterale carpi ulnare). In addition, from the radial bone to the bones of the wrist from the palmar surface, the palmar wrist band (lig. Radiocarpeum palmare) is stretched. The same bundle (lig. Radiocarpeum dorsale) is also present on the back side (Fig. 1 and 2). The capsule of the wrist joint eats from the vessels that form the rete carpi palmare (see Brush).
On the palmar surface of the wrist joint there are two synovial vagina, in which under the retinaculum flexorum - a dense ligament, which is a continuation of the palmar aponeurosis, the flexor tendons of the fingers pass. The main muscles flexing the hand are the radial and ulnar flexors of the wrist (hand) and the long palmar muscle (mm. Flexor carpi radialis, palmaris longus et flexor carpi ulnaris). The extension of the hand is produced by the long and short radial extensors of the wrist (hand) and the ulnar extensor (mm. Extensores carpi radiales longus et brevis et m. Extensor carpi ulnaris). The extensor tendons at the level of the wrist are in the vagina and pass under the exteninum retinaculum. On the palm surface of the wrist joint, the tendons and muscles are located in four layers, on the back - in two layers. In addition to these muscles of the flexors and extensors of the hand, the remaining muscles have an indirect effect on the function of the joint.
The blood supply from the palm side of the joint receives from the radial and ulnar arteries. The radial artery is accompanied by two veins and is located superficially. The ulnar artery passes through the ulnar groove of the forearm accompanied by two veins. Medially from the artery, the ulnar nerve is located. The median nerve passes along the palmar surface of the wrist joint, along with flexor tendons. Unlike the tendons, having a lamellar structure in the section, the median nerve has a cable structure (consists of separate longitudinal fibers). This is important to remember when stitching the ends of damaged tendons and nerve. The back surface of the wrist joint receives blood supply from the back of the wrist of the radial artery (ramus carpeus dorsalis) and the dorsal artery of the wrist joint (rete carpi dorsale).
The wrist joint is an ellipsoidal biaxial joint that allows movement in the sagittal and frontal plane of the hand.