CLAVICLE

From Big Medical Encyclopedia

CLAVICLE (clavicula) — the tubular pair bone of a shoulder girdle which is jointed with a breast and a shovel. Functionally To. belongs to an upper extremity, it serves as border between area of a neck and a trunk in the anatomic relation.

Anatomy

Fig. 1. The right clavicle (and — a dorsal view — a ventral view): 1 — the acromial end; 2 — a sternal joint surface; 3 — the sternal end; 4 — an acromial joint surface; 5 — coronoid tuberosity; 6 — a feed throat; 7 — costal tuberosity.

To. has the form of the extended letter S (fig. 1); length To. adult of 12 — 15 cm. Medial part K. (apprx. 2/3 lengths) it is curved kpered, a lateral third — kzad and comes to an end with the plate of a spongy structure flattened from top to down. Average department To. a cylindrical form, has the marrowy channel. The sternal end is thickened, has the form of a trihedral prism with stupid edges and the expressed rough impression on the lower party caused by an attachment of a costoclavicular sheaf. On the lower party of the acromial end To. there is a cone-shaped hillock (tuberculum conoideum) and the trapezoid line (linea trapezoidea) — places of an attachment of a klyuvoklyuchichny sheaf. The deltoid muscle (m. deltoideus), from above and behind — a trapezoid muscle (m. trapezius) is also in front attached to the acromial end from above.

The acromial end To. it is jointed with an acromial shoot of a shovel, forming a clavicular and acromial joint. Mobility in it is caused by the weak tension of the joint capsule and a fibrocartilage layer between bones, edges quite often forms in more or less isolated disk. The joint is strengthened by two sheaves: acromial and clavicular (lig. acromioclaviculare) and klyuvoklyuchichny (lig. coracoclaviculare).

The sternal end To. it is jointed with a breast (a grudinoklyuchichny joint). The joint is divided into two cavities by a cartilaginous joint disk. Stability of a joint is caused by powerful sheaves. With the I edge To. it is connected by a two-layer costoclavicular sheaf (lig. costoclaviculare). In front and behind the grudinoklyuchichny joint is strengthened a front and back grudinoklyuchichnyma by sheaves (lig. sternoclaviculare ant. et post.). Through jugular cutting across there passes the interclavicular sheaf (lig. interclaviculare).

By the sternal end To. at its rear edge it is attached grudino - a clavicular and mastoidal muscle (m. sternocleidomastoideus), from below — a grudinopodjyazychny muscle (t. sternohyoideus). To medial two thirds To. the big pectoral muscle (m. pectoralis major) is in front attached. On a lower surface To. between the I edge and its acromial end there passes the subclavial muscle (m. subclavius). Here the feed throat (foramen nutricium) is located, through a cut vessels get into a bone.

Grudinoklyuchichny and clavicular and acromial joints participate in the active movements of an upper extremity. To their participation there is a rise it above the horizontal line, advance and aside. Functional value K. consists that it is «strut» between bones of a trunk (breast) and a shoulder joint (see. Shoulder girdle ). It stabilizes a joint and increases the volume of movements in it.

At the level of an average third To., behind it, between an attachment deltoid and big chest muscles, kpered from the I edge there pass a subclavial artery and a vein and a brachial plexus.

Age features To.: the first kernels of ossification appear in a body To. on 5 — 6th week of an antenatal life also merge on the 7th week. A kernel of ossification in the cartilaginous sternal end To. appears in 16 — 20 years and merges with a body To. by 20 — 25 years.

A radioanatomy

For X-ray inspection To. apply a X-ray analysis in front and back projections, sometimes in a lobby bilateral — to obtaining the symmetric image both To., and also in a so-called upper projection — for receiving: images To. out of a background of edges (at a path of rays from below in front, along a front wall of a thorax). In the presence of indications use: tomography (see). All pictures To. make at the held breath.

Fig. 2. Front roentgenogram of a normal right clavicle.

In pictures in a direct projection a S-shaped curvature To. in the horizontal plane it is concealed (fig. 2). The wide flat acromial end To. it is projected against the background of covers of small thickness and therefore it seems rarefied; it has a small joint surface. On the lower contour To., near the sternal end, the impression in the place of an attachment of a costoclavicular sheaf which sometimes is mistakenly taken for the center of destruction is visible. In a diaphysis To. the bast layer and a marrowy cavity, and in the ends — spongy structure and a thin bast layer are expressed. Near an upper contour To. in a diaphysis the oblong enlightenment to dia, to 3 mm — the channel for a lateral branch of an average supraclavicular nerve sometimes meets.

Pathology

Inborn deformations

Inborn deformations meet seldom and are divided into two groups: 1) disturbances of the sizes and form K. — an additional coronoid and clavicular, costoclavicular joint, bifurcation To.; 2) so-called defective anomalies — lack of a part or all To., perforated To., clavicular and cranial dysostosis (see).

At inborn deformations To. in a case funkts, disturbances operational treatment (bone plastics) is shown.

Damages

Dislocations of a clavicle, according to a number of authors, make from 3 to 19% of all dislocations. Distinguish dislocations of the sternal and acromial ends K.

Boley dislocations of the acromial end are frequent To., arise usually at blow to an acromial shoot of a shovel or during the falling on the given shoulder; they can be incomplete (incomplete dislocations at a gap or an anguish of one clavicular and acromial sheaf) and full (at a gap as well klyuvoklyuchichny sheaf). At dislocation of the acromial end To. under skin its vystoyaniye is visible, and during the pressing mobility («a symptom of a key») from above is defined. At suspicion of dislocation of the acromial end To. do bilateral pictures (for comparison with the opposite side) in vertical position of the patient since in horizontal position shift can independently be eliminated. On the roentgenogram at dislocation or an incomplete dislocation the shift of the acromial end is visible To. up.

Dislocation of the sternal end To. happens incomplete (incomplete dislocation) and full. Distinguish presternal, nadgrudinny and retrosternal dislocations. These dislocations are difficult for diagnosis since deformation does not happen considerable, and on the front bilateral roentgenogram asymmetry of the sternal ends To. comes to light only at nadgrudinny dislocation.

For reposition of dislocations of the acromial end To. under local anesthesia the shoulder is raised, taken away back and pressed from above on the outside end To. For deduction To. in such situation there is a large number of plaster bandages and tires which general principle is pressure from above upon the acromial end To. Good results are achieved by use of stage bandages like «sword belt» which main advantage is the constant pressure upon the acromial end To., reliability of its immobilization and possibility of early recovery of function of a shoulder joint. As the pressing element of these bandages serves in the first 3 weeks the replaceable plaster splint, and then the rubber medical bandage put in several layers. Full and old (in 3 weeks and more after an injury) dislocations of the acromial end of a clavicle usually treat quickly. Fixing gained distribution To. to acromial and coronoid shoots by means of silk thread, the combined method — connection K. with a coracoid a mylar tape, with an acromial shoot — Kirchner's spokes and an osteosynthesis of a joint metal fixers. After operation apply a plaster bandage like Dezo with the roller in an axillary hollow 3 — 4 weeks (see. Desmurgy ). At fresh dislocations of the sternal end To. it is easy to make the closed reposition, however to hold the set end To. it is extremely difficult. Therefore carry quite often out open reposition of dislocation with fixing by one or several spokes. An immobilization after operation — to 6 weeks.

Fractures of a clavicle make apprx. 3% of all changes. Direct blows on To. rather seldom are the reasons of its changes. The last are called by indirect influence more often on To.: falling arm-distance, blow in a shoulder joint, a prelum of a body in the sagittal plane etc.

Fig. 3. The diagrammatic representation of typical shift of fragments at a fracture of a clavicle: 1 — grudino - a clavicular and mastoidal muscle; 2 — internal fragment; 3 — a subclavial muscle; 4 — outside fragment.

The most frequent localization of changes To. — border of average and outside its thirds that is caused fiziol, its bend and the smallest mechanical strength in this place. At adults changes happen cross, slanting, splintered, is frequent with considerable shift. At children subperiostal changes as «bent» are more often observed. Under the influence of muscular draft at a change To. the lateral end ev is displaced from top to bottom and kpered, and medial — up and knutr (fig. 3). Occasionally changes To. are fraught with danger of break of skin acute fragment, wound of subclavial vessels and a parietal pleura.

For changes To. all classical signs are characteristic changes (see): deformation in the form of a swelling and quite often vystoyany under skin of the ends of fragments, a hypodermic hematoma, sharp morbidity, palpation of bone fragments and their crepitation in the area K., dysfunction of the corresponding upper extremity. The shoulder joint on the party of a change is displaced down and slightly forward, the head is inclined towards damage. At subperiostal changes at children the symptomatology is limited to a swelling, morbidity at a palpation To. and at the movements of an upper extremity. On the roentgenogram the line of a change of K. V doubtful cases (e.g. is accurately visible, at changes without shift, changes as «bent» at children) the X-ray analysis both is necessary To. on one film.

Fighting injuries To. are followed by damage of neurovascular educations, a lung, nearby large bones and a big array of soft tissues (see. Wounds, wounds ) and in this regard massive bleeding (see) and traumatic shock (see. Shock ).

Treatment of changes To. can be conservative and operational. The conservative method is applied most often, especially at children.

Fig. 4. The figure-of-eight bandage applied after reposition at a fracture of a clavicle: 1 — a stage of imposing; 2 — an anterior aspect; 3 — the back view

For single-step reposition of a change, To., made under local anesthesia of 2% solution of novocaine (15-20 ml), the patient is seated on a stool, and the assistant both hands, standing behind, parts shoulders of the patient so that to pull together inner edges of shovels among themselves. The surgeon a thumb makes at this time reposition of fragments To. with the subsequent immobilization (see). Deduction of fragments presents considerable difficulties that explains existence more than 250 different types of bandages and tires for treatment of changes To. The greatest distribution was gained by Kuzminsky, Kaplan, Chaklin's tires, a figure-of-eight bandage (fig. 4), plaster bandages like Dezo, Sitenko, etc. Consolidation of a change To. in most cases comes at an immobilization during 4 — 6 weeks, it is frequent about a nek-eye the shift of fragments. However function of a hand at the same time, as a rule, does not suffer. Failure of union of a change is observed extremely seldom, it is connected with considerable interposition of soft tissues in a zone of a change or with rough errors of an immobilization.

Fig. 5. Intramedullary osteosynthesis of a clavicle: 1 — the acromial end of a clavicle; 2 — a sternal joint surface; 3 — the sternal end of a clavicle; the dotted line showed the metal core entered into a bone which passed through the line of a change.

The indication to operational treatment are only changes with the considerable shift of fragments and interposition of soft tissues, threat of break of skin of fragment To. and damages of vessels, nearthroses To. with dysfunction of an extremity. Use various options of intramedullary fixing of fragments To. (fig. 5). Irrespective of a way of an osteosynthesis (Shch.) after operation apply a plaster bandage 6 — 10 weeks, and sometimes and more long term.

Diseases

Osteomyelitis (see). To. more often happens at children, strikes usually sternal end To. Treatment operational — necretomy (see), sequestectomy (see), a resection To.

The diagnosis of specific defeats (tuberculosis, syphilis, an actinomycosis) To. put on the basis of characteristic clinic, rentgenol, and a lab. data. Treatment surgical in a combination to specific antibacterial therapy (see. Actinomycosis , Syphilis , Tuberculosis of bones and joints ).

At youthful age there is an osteochondropathy of the sternal end To., edges consists in an aseptic subchondral necrosis (see. Friedrich syndrome ).

Tumors

Most often meets sarcoma (see), osteoblastoclastoma (see), osteoma (see) and angioma (see). Treatment depends on a look and the nature of a tumor.



Bibliography: Kaplan A. V. The closed injuries of bones and joints, M., 1967, bibliogr.; Krupko I. L. Guide to traumatology and orthopedics, book 1, L., 1974, bibliogr.; The multivolume guide to orthopedics and traumatology, under the editorship of N. P. Novachenko, t. 2, page 480, t. 3, page 381, M., 1968; Nadj D. X-ray anatomy, the lane with Wenger., page 56, Budapest, 1961; Reynbergs. A. Radiodiagnosis of diseases of bones and joints, t. 1 — 2, M., 1964; Watson-D zhonsr. Fractures of bones and injury of joints, the lane with English, M., 1972; In u n n e 1 I S. Surgery of the hand, Montreal — Philadelphia, 1964; Herman S. Congenital bilateral pseudarthrosis of the clavicles, Clin. Orthop. related Res., No. 91, p. 162, 1973; Kohler A. u. Zimmer E. A. Grenzen des Normalen und Anfange des Pathologischen im Ront-genbilde des Skelettes, S. 168, Stuttgart, 1956; Sycamore L. K. Common congenital anomalies of bony thorax, Amer. J. Roentgenol., v. 51, p. 593, 1944.


AA. P. Mathis; S. I. Finkelstein (rents.).

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