FOREARM [antebrachium (PNA, JNA); antibrachium (BNA)] — an average segment of an upper extremity.
Borders: the upper circular line drawn 5 — 6 cm below than epicondyles of a humeral bone; lower passes across the circular line connecting tops of awl-shaped shoots of elbow and beam bones. At P.'s survey many of bone and myagkotkanny formations of this segment (fig. 1) are visible.
The bone basis of P. is made by beam and elbow bones. An epiphysis of bones connects among themselves proximal and distal radioulnar joints (articulationes radioulnares proximalis et distalis) that gives the chance to make the movements of a beam bone around an elbow knaruzha (supination) and knutr (pronation). An epiphysis of beam and elbow bones is strengthened by sheaves, a diaphysis connects a slanting chord and an interosseous membrane of P. (fig. 2). Skin on P. thin, mobile, with indumentum on back and side surfaces. Own fascia, giving fascial partitions to P.'s bones, forms fascial beds: front, outside and back. Muscles are separated from each other by fascial spurs of own fascia. Above the fascia is strengthened by an aponeurosis of a biceps (aponeurosis m. bicipitis brachii), and below — retinaculums of sgibately and razgibately (retinaculum flexorum et extensorum). In a front fascial bed in four layers the front group of muscles is located: a first coat — the round pronator (m. pronator teres), a beam sgibatel of a wrist (m. flexor carpi radialis), a long palmar muscle (m. palmaris longus); the second — a superficial sgibatel of fingers (t. flexor digitorum superficialis); the third — a deep sgibatel of fingers (m. flexor digitorum profundus), a long sgibatel of the I finger of a brush (t. flexor pollicis longus); the fourth — the square pronator (m. pronator quadratus). Between the second and third layers the front intermuscular kletchatochny crack is located; between the third layer and an interosseous membrane — a front intermusculoskeletal kletchatochny crack; between the square pronator, an interosseous membrane and both bones of P. — Pirogov's space. In an outside fascial bed there is an outside group of muscles: humeroradial (m. brachioradialis), long and short beam razgibatel of a wrist (m. extensor carpi radialis longus et brevis). In a back fascial bed in two layers the back group of muscles lies down: a first coat — an elbow muscle (m. anconeus), an elbow razgibatel of a wrist (m. extensor carpi ulnaris), a razgibatel of the V finger (m. extensor digiti minimi), a razgibatel of fingers (m. extensor digitorum); the second layer — an instep support (m. supinator) in an upper third below — a razgibatel of the II finger (m. extensor indicis) and initial departments short and the long I finger of a razgibately brush (mm. extensores pollicis longus et brevis), the long muscle which is taking away the I finger of a brush (m. abductor pollicis longus); between the first and second layers the back intermuscular crack is located; between the second layer, an interosseous membrane and both bones the back intermusculoskeletal kletchatochny crack is located. The Supinatorny channel (canalis supinatorius) represents a slit-like interval between a beam bone and an instep support. In it there passes the deep branch of a beam nerve (m. profundus n. radialis). The front group of muscles bends fingers and a brush and pronirut a forearm; outside and back — unbends fingers and a brush and supinates a forearm.
In hypodermic cellulose P. medial (v. basilica) and lateral (v. cephalica) superficial veins, and also a median vein of P. (v. mediana antebrachii) and their inflows are located (tsvetn. silt., fig. 1,3). Deep veins of P. (vv. commitentes) accompany arteries. The lobby and side surfaces of P. are innervated medial and lateral by cutaneous nerves of P. (nn. cutanei antebrachii med. et lat.), back — a back cutaneous nerve of P. (n. cutaneus antebrachii post.). It is possible to allocate beam, elbow, front and back interosseous vascular nervous bunches and a median nerve for P. (tsvetn. silt., fig. 2,4). Beam artery and veins, superficial branch of a beam nerve (and. et vv. radiales, r. superficialis n. radialis) are located between a radioulnar muscle and a beam sgibatel of a wrist. Elbow artery, veins and nerve (a., vv. et n. ulnares) pass 2/3 forearms in lower between an elbow sgibatel of a wrist and a deep sgibatel of fingers, and in an upper third the elbow artery lies knaruzh from a nerve on a deep sgibatel of fingers. Front and back interosseous arteries (aa. interosseae ant. et post.) with the veins of the same name and nerves pass on front and back surfaces of an interosseous membrane; a median nerve (n. medianus) — between deep and superficial sgibatel of fingers. The front group of muscles is innervated median and partially elbow by nerves, outside and back — a beam nerve.
Limf. P.'s vessels form from limf, capillaries of muscles, fastion, hypodermic cellulose and skin. They bring a lymph to elbow and axillary nodes.
Pictures of a diaphysis of bones of a forearm make in direct and side (ul-narny) projections, according to indications — in slanting projections. A diaphysis of beam and elbow bones is unsharply dugoobrazno bent (fig. 3). Thickness of an ulna in the distal direction decreases, and a beam bone, on the contrary, increases. Width of compact substance unequal, it has the greatest density and thickness on adjacent surfaces of bones of a forearm, i.e. adjacent to an interosseous membrane. The most reinforced sites of cortical substance are called crests. In view of uneven density they are mistakenly taken sometimes for a periostitis. On the course of a diaphysis of bones the gleam of the marrowy channel clearly is differentiated. The located lines of an enlightenment crossing cortical substance slantwise are display of nutrient canals.
Malformations meet seldom. Treat them: a hemimelia — total absence of all forearm; a fokomeliya — an underdevelopment of a shoulder and P. when the brush begins directly from a trunk; a peromeliya — total absence of all upper extremity when the insignificant rudiment departs from a trunk. Inborn absence or an underdevelopment beam or an ulna quite often happens symmetric and involves inborn talipomanus (see).
Congenital dislocation of a beam bone develops on the soil patol. shortenings of an ulna with a normal length of a beam bone. The head of a beam bone is usually deformed what restriction of rotation, bending and extension of the Item is connected with. Treatment operational — a resection of a head of a beam bone at the patients who reached 14 years.
Damages Items can be closed and opened. Treat the closed injuries bruises (see), ruptures of muscles and sinews (see. Distortion , Muscles ), and also fractures of bones (see. Changes ). At considerable subfascial hematomas owing to P.'s bruises the prelum of vessels, nerves and muscles is possible that is shown by ischemia, disturbance of skin sensitivity and function of a brush. In these cases the section of skin and a fascia and removal of a hematoma are shown. Hypodermic ruptures of muscles and P.'s sinews meet seldom.
They can be full and partial. Diagnostic characters is local morbidity, a hematoma, dysfunction of a brush or fingers. At partial damages conservative treatment is shown. Complete separations are subject to operational treatment with suture on the injured muscle or a sinew.
At wounds of soft tissues of P. make primary surgical treatment of wounds (see).
Fractures of bones of a forearm among all fractures of bones make from 5 to 25%. They can be open and closed.
Changes of a head of a beam bone, an elbow shoot, a coronal shoot of an ulna — see. Elbow joint .
Changes of a diaphysis of bones of P. arise at influence of a direct or indirect injury. Changes can be in an upper, average and lower third of bones of P., one beam, one ulna, both bones of P., a diaphysis of an ulna with dislocation of a head beam — Montedzhi's change (fig. 4, a), a diaphysis of a beam bone with dislocation of a head of an ulna — a change of Galeazzi (fig. 4, c). Diaphyseal fractures of bones of P. happen cross, slanting, splintered, shattered. Shift of fragments on width, length, at an angle and rotational shift is possible. Children have subperiostal changes (fig. 5) more often — as «bent» when the remained periosteum holds fragments of a bone and therefore their shift is expressed unsharply.
The epiphysiolysis which meets in distal department of a beam bone more often can result from an injury. Degree of an epiphysiolysis happens various — from small asymmetric expansion of a zone of a metaepiphyseal cartilage to an epiphysiolysis on a half and more than a diameter of a bone. As a rule, together with an epiphysis the small bone fragment which is coming off at the same time a metaphysis is displaced (osteoepifizeoliz).
The change of the distal end of a beam bone (a change in the typical place) arises on site the former rostkovy zone (2 — 2,5 cm from a joint crack), peripheral fragment of a beam bone is displaced in the back of P. — Kollis's change (see. Kollis change ); during the falling on a dorsum of a brush peripheral fragment is displaced in the palmar party (Smith's change).
At the isolated injuries of separate bones local symptoms of a change — local pain, disturbance of a form and function P. and a brush are defined (see. Changes ). Pay attention to a state distal (at a fracture of a beam bone) and proximal (at a change of an ulna) radioulnar joints since dislocation of bones is possible at the same time. During the carrying out a X-ray analysis pictures do in two projections with capture of elbow and radiocarpal joints.
At the closed fractures of both bones of P. without the shift of fragments impose for 2 — 2,5 months a plaster bandage in situation P., an average between pronation and supination, during the bending in an elbow joint to 90 °. At the closed P.'s changes with the shift of fragments carry out them reposition (see) then apply a circular plaster bandage (see. Plaster equipment ). Rentgenol. control is exercised right after reposition, and also in 10 — 14 days after it, after the termination of hypostasis of fabrics. Term of an immobilization plaster bandage of 2,5 — 3 months. Working capacity is recovered in 4 — 5 months after a change. At the isolated fractures of bones of P. the same tactics.
Resort to an osteosynthesis at the unsuccessful closed reposition, secondary shifts in a plaster bandage, and also at Montedzhi's changes and Galeazzi. It is most widespread bone or nailing of bones of a forearm (see. Osteosynthesis ). At Montedzhi's change set dislocation of a head of a beam bone and temporarily fix it chreskostno a spoke, and then carry out an osteosynthesis of fragments of an ulna. At chronic dislocations of a head of a beam bone its resection is shown. At a change of Galeazzi the osteosynthesis of a beam bone is carried out by a plate, set dislocation of a head of an ulna. After an osteosynthesis for 2,5 — 3 months apply a plaster circular bandage. At fractures of bones of P. the heavy complication — Folkmann's contracture can develop (see. Contracture ).
Open fractures of bones of P. arise at a direct injury from the outside (often splintered and shattered changes), and also as a result of a puncture of soft tissues and skin the acute ends of fragments from within.
In case of open fractures of bones of P. without the shift of fragments, and also after successful reposition of fragments apply a cutting circular or longetny plaster bandage. The submersible osteosynthesis can be carried out by metal designs during surgical treatment of a wound at a small zone of damage of soft tissues, in the absence of signs inf. complications and at a possibility of stitching on a wound. At the multisplintered and shattered changes, and also at extensive wounds of P. fixing of fragments devices for chreskostny fixing is more reasonable (see. Distraktsionno-kompressionnye devices ).
In treatment of fractures of bones of P., in addition to an immobilization of fragments, the big role belongs to remedial gymnastics. It is connected with the fact that effects of injuries of P., especially fractures of bones, have an adverse effect on function of a brush. After imposing of a plaster bandage on 2 — the 3rd day there begin the movements in joints of a hand, free from a plaster bandage. Carry out various movements by fingers (bending and extension, cultivation and the data, opposition), the movements on all axes of a shoulder joint. Apply the exercises including static tension with the subsequent relaxation to the muscles which are under gypsum. After the termination of an immobilization the injured hand in its initial position on a surface of a table of the patient carries out exercises for fingers, the movements in a radiocarpal joint, pronation and P.'s supination, the movements in an elbow joint. Exercises in warm water in the form of active movements by a brush and fingers give good effect. At it is long the remaining puffiness of a brush light massage of a forearm is shown. At the end of treatment in joints and strengthenings of muscles of a hand apply rubber bandage, dumbbells, expanders to further increase in amplitude of movements. For acceleration of recovery of working capacity widely use work therapy (a vvertyvaniye the screw-driver of bolts, work with a plane and a file, winding of threads on a ball, pasting of envelopes, etc.).
Features of fighting damages, stage treatment. At use of modern types of arms the gunshot wounds of P., damages caused by a shockwave (the closed and open fractures of bones, prelums, etc.), and also the combined damages can be observed. P.'s damages classify by the form a hurting shell, to character and localization of wound, a type of a change, rate of decay of soft tissues, and also by the accompanying damages. Fire fractures of bones of P. during the Great Patriotic War made 36,7% of fire fractures of long tubular bones. 7,4% had damages of vessels accompanying P.'s changes, nerves — at 30,5% of wounded. P.'s wounds bullets of small caliber with high initial velocity of flight are followed by extensive destruction of soft tissues in the field of outlet opening, multisplintered fractures of bones, is frequent with defect of a bone tissue (fig. 6).
At diagnosis of changes of P. take into account: P.'s deformation, an arrangement of entrance and output openings and the direction of the wound channel, existence of the bone fragments seen in a wound, patol. mobility at the level of wound, pain in the field of a change, restriction of active and passive movements of a brush and fingers. The final diagnosis is established after carrying out rentgenol, by researches.
First aid: a stop of bleeding by means of a compressing bandage or a plait, imposing of an aseptic bandage, P.'s immobilization make-shifts, introduction of analgetics.
Pre-medical help: control and correction of the applied bandages, tires and styptic plaits, introduction of analgetics, according to indications improvement of an immobilization by means of wire or plywood tires.
First medical assistance: correction or replacement of bandages, tires and styptic plaits, a temporary stop of bleeding — an alloying of the damaged vessel or its crossclamping in a wound a styptic clip, introduction of analgetics, antibiotics, antitetanic serum and tetanic anatoxin.
The qualified medical care is usually provided according to urgent indications (the proceeding bleeding, a separation and crush of an extremity, a mephitic gangrene).
Specialized medical care: surgical treatment of a wound and reliable immobilization of fragments a plaster bandage, according to indications during surgical treatment an economical resection of the fragments shattered and an oskolcha of ty fractures of bones of P. for the purpose of implementation of reliable fixing of fragments metal designs.
Diseases. The miositis develops after various inflammatory processes and infectious diseases (flu, tonsillitis, abscesses, phlegmons, etc.). It also systematic overstrain of muscles of P. causing them overfatigue can be the cause. The miositis is shown by persistent pains, muscular weakness and dysfunction of a brush. Treatment — rest, novocainic blockade, thermal procedures, superficial massage. In cases of a persistent current of a miositis apply P.'s immobilization (see. Miositis ).
The aseptic tendovaginitis of sinews of P. can arise at hard physical work. More often this process is struck by a razgibatel of fingers and beam and an elbow razgibatela of a wrist. Treatment — two-or triple irrigation by Aether chloratus of skin on the course of the interested sinew with an interval of 2 — 3 days; rest and heat. The acute purulent tendovaginitis of sgibatel of fingers of a brush which is usually a complication felon (see), can be followed by purulent fusion of fabrics and break of pus in Pirogov's space. Treatment operational (see. Tendovaginitis ).
Osteomyelitis can be hematogenous and posttraumatic (as a complication of fire or open not fire changes) or postoperative. Hematogenous osteomyelitis of bones of P. arises less than other bones of a skeleton. The metafizarny department of bones is surprised more often, diaphyseal is more rare. Treatment is carried out by the principles accepted for treatment of osteomyelitis (see. Osteomyelitis, treatment ).
Tuberculosis proceeds usually with defeat of epiphyseal and metafizarny departments of bones of P. (cm. Tuberculosis extra pulmonary ).
The syphilitic osteoperiostitis of bones of P. more often happens asymmetric, to focal pristenochny uzura. At recognition data a wedge are of great importance. pictures and lab. researches. Treatment specific (see. Syphilis ).
Mycoses (an actinomycosis, a spirotrichosis, an aspergillosis, etc.) extremely seldom affect P.'s bones (see. Mycoses ).
In P.'s bones changes at a hyperparathyreosis can be observed, Pedzhet's diseases, the localized cyst and an osteoblastoclastoma meet (see. Bone cyst , Osteoblastoclastoma , Parathyroid osteodystrophy , Pedzheta disease ).
After damages and various diseases of muscles and P.'s sinews, and also after fractures of bones of P. there can be contractures of a brush and fingers, a rotational contracture of P., a special form of a contracture — folkmannovsky (see. Contracture ). Total absence of rotation of P. can be caused, in addition to pathology elbow joint (see) or radiocarpal joint (see), to also posttraumatic radioulnar synostosis (see).
Tumors. Benign tumors. In soft tissues of P. can develop angioma (see), lipoma (see), fibroma (see. Fibroma ), lymphangioma (see), in bones — hondroblastoma (see), chondromyxoid fibroma, chondroma (see), osteoblastoclastoma (see), osteoma (see), osteoidosteoma (see), etc. Treatment operational — radical removal of the center of defeat with the subsequent bone auto-or an alloplasty of defect.
Malignant tumors. Soft tissues of P. can be a source of development rhabdomyosarcomas (see) and fibrosarcomas (see). Ewing's sarcoma (see. Ewing tumor ), chondrosarcoma (see), a myeloma, a reticulosarcoma of bones (see. Reticulosarcoma of a bone primary ) to areas P., and also metastasises of malignant tumors are observed seldom. Treatment usually operational with the subsequent radiation therapy. In early stages savings operations — wide resections of bones of P. with a bone alloplasty are possible. In late stages amputation at the level of a shoulder is shown. The forecast for life is defined by timeliness of the carried-out treatment; at savings operations function P. is substantially recovered.
Access to a diaphysis of a beam bone can be provided on outside, palmar or the back of P.; access to a diaphysis of an ulna — on internal, a palmar pla to the back of the Item. The elbow artery and an elbow nerve are bared by means of palmar and elbow access. The section of skin at the supinated P. is made from a medial epicondyle of a shoulder to the outer edge of a pea-shaped bone. After a section of a fascia the elbow artery and an elbow nerve are found in an interval between an elbow sgibatel of a brush and a superficial sgibatel of fingers. The beam artery and a superficial branch of a beam nerve are bared by means of palmar and beam access. The section of skin is made at the supinated situation P. on the line connecting the outer edge of a sinew of a biceps of a shoulder and an awl-shaped shoot of a beam bone. The artery and a superficial branch of a beam nerve are bared between the round pronator and a humeroradial muscle.
P.'s amputation in an upper and average third is carried out by a scrappy or circular way with a cuff. Median, elbow and beam nerves shorten on 4 — 5 cm to exclude a possibility of formation of an amputating neuroma under skin at the end of a stump. Muscles and sinews cross in one plane on 3 — 4 cm distalny opit bones. P.'s bones saw round at one level, edges smooth them a rasp. Vessels tie up a catgut (see. Amputation ). According to indications carry out cinematization of a stump (see. Krukenberg hand ). The resection of bones of P. is carried out at tumors, in certain cases osteomyelitis and nearthroses.
Lengthening of bones of P. is shown at talipomanus (see), the inborn and acquired shortenings. After a slanting osteotomy lengthening is carried out by means of distraktsionno-compression devices. The osteotomy in the area P. is similar according to indications and the equipment of an osteotomy of other long tubular bones (see. Osteotomy ).
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C. C. Tkachenko; V. P. Illarionov (to lay down. physical.), M. K. Klimova (rents.), E. R. Mathis (hir.), A. A. Travin (An.).