From Big Medical Encyclopedia

SYNOSTOSIS (synostosis, Greek syn-together, with osteon a bone + - osis) — a bone union of two bones or parts of one bone among themselves. An union of bones in a joint call bone anchylosis (see).

Process of an union of fragments of a bone later change (see) with education bone callosity (see) it is accepted to call consolidation.

Distinguish S. spontaneous (anatomic, inborn and posttraumatic) and artificial, prepared in the operational way.

Anatomic synostosis — this normal, coming in certain time, fiziol. an union among themselves parts of a bone in the course of its growth — an epiphysis with metaphyses, apophyses with ground mass bones (see). The terms of approach of anatomic S. studied according to roentgenograms use as objective criterion of physical development and age (see. Age bone ). Disturbances of an anatomic sinostozirovaniye and the delay or acceleration of growth of a bone connected with it are observed at a number patol. states, is more often than endocrine system, napr, at dwarfism (see), the general infantility (see), eunuchoidism (see), Kashin's diseases — Beck (see. Kashina — Beck a disease ), hypergenitalism (see), Blant's diseases (see. Blanta disease ).

Inborn synostosis — patol. an union of the next bones owing to aplasia (see) or hypoplasias of connecting fabric between the next bones. This process is the cornerstone of inborn radioulnar S. (see. Elbow joint ). Various forms of inborn S. are observed in backbone (see), napr, at Klippel's disease — Feylya (see. Klippelya — Feylya a disease ). S. of several edges in the form of a plate, by S. additional (so-called cervical) edges with the I edge, an union (concrescense) of phalanxes of fingers is described at a bone form of a syndactylia (see). Carry also premature union of bones of a skull in its seams at a craniostenosis to inborn S. (see).

Posttraumatic synostosis — an union of the next bones after an injury of a periosteum, a bone tissue or damage of a proliferative zone of an epiphyseal cartilage. Arises between the next vertebrae, bones of a forearm or a shin more often.

Fig. 1. The roentgenogram of the left elbow joint and bones of a forearm in 1 year after a double change of an ulna: 1 — a synostosis between beam and elbow bones in the place of the former change of an ulna; in the field of a synostosis uniform transition of structure of one bone to structure another is visible; 2 — area of incorrectly accrete change of an ulna; 3 — a serklyazhny wire seam.
fig. 2. The roentgenogram of an elbow joint (a side projection) in 2 months after a resection of a head of a beam bone: the arrow specified the growth of a bone tissue connecting opit a beam bone and an ulna.
Fig. 3. The roentgenogram of a distal part of a shin and ankle joint (direct projection) in 1 year after a fracture of a fibular bone with a rupture of a distal intertibial syndesmosis: the arrow specified the growth of a bone tissue connecting tibial and fibular bones; two serklyazhny wire seams fixing fragments of a fibular bone are visible.

After a regional fracture of a body of a vertebra or its dislocation quite often there is an ossification of a front longitudinal ligament of backbone and S. of two vertebrae. At a fracture of bones of a forearm with the shift of fragments sometimes perhaps mutual rapprochement of beam and elbow bones in a zone of an injury. Damaged in this place periosteum (see) produces a bone tissue, edges are filled by a crack between bones that, eventually, leads to S. of bones of a forearm on. the isolated site (fig. 1). It is possible to carry a bone union as a complication of an operative measure on a bone to posttraumatic S., napr, radioulnar S. after a resection of a head of a beam bone (fig. 2); the main symptom of this S. is total absence of rotation of a forearm. At a change of the lower quarter of a fibular bone quite often there is a rupture of linking of a distal intertibial syndesmosis. At the same time ossification of sheaves — intertibial posttraumatic S. (fig. 3) can be observed. At the heart of S.'s pathogeny after changes or operative measures lies fiziol. the process of an osteogenesis observed at development of a bone callosity.

Fig. 4. The survey roentgenogram of a basin of the child in 6 years after a difficult injury of a basin with a change of the left acetabular hollow: there is no x-ray crack of the left igrekobrazny cartilage well noticeable on the healthy party (it is specified by an arrow) that testifies to a synostosis of an acetabular hollow; bones of the left half of a basin and the left femur of an atrofichna are also deformed.

At an epiphysiolysis (see. Changes ) sometimes there is a premature ossification of a part of an epiphyseal cartilage that slows down growth of a bone in length and leads to varus or valgus deformation of an extremity. At injury of an igrekoobrazny cartilage of an acetabular hollow development of a difficult clinicoradiological symptom complex owing to early S. of an acetabular hollow (fig. 4) is possible.

The most authentically posttraumatic S. is defined radiological. Posttraumatic S.'s treatment is carried out only in those cases if it considerably limits the movements in an adjacent joint. The resection of a bone in the area C. is made with implementation of laying from biological or synthetic material between the next bones (see. Arthroplasty ). After operation from the first days appoint LFK. S.'s recurrence therefore its prevention at treatment of fresh changes is important is quite often observed: exact reposition of fragments, use of atraumatic methods repositions (see), stable osteosynthesis (see).

Fig. 5. The flow diagram Ghana (a) and its modifications (b) at elimination of defect of a tibial bone: and — the proximal end of the crossed fibular bone is implemented in the central part of tibial; — the ends of the transplant created from a fibular bone are implemented in distal and proximal fragments of a tibial bone.
Fig. 6. The scheme of operations of a bypass synostosis at defect of a tibial bone: and — according to Stewart — to Bogdanov; in a distal and proximal epiphysis of tibial bones from a fibular bone canals into which are densely entered bone auto-are slantwise drilled or allotransplants (are shaded); — across Bogdanov — to Antonyuk; except two transplants entered into an epiphysis of tibial bones the third transplant through a fibular bone is carried out to a zone of defect of a tibial bone.

The artificial synostosis is created between bones, most often tibial, for treatment of an inborn or posttraumatic nearthrosis or defect of a tibial bone. One of the first such ways can consider operation Ghana (fig. 5). However afterwards similar operational S. were forced out by typical operations bone plastics (see). The operational sinostozirovaniye keeps the relevance when because of extensive cicatricial process or big bone defect intervention in the center of damage is fraught with a necrosis of soft tissues or suppuration. In such cases use bypass S.'s operation on Stewart — to Bogdanov or her modification across Bogdanov — to Antonyuk (fig. 6). After an union of tibial and fibular bones and S.'s education in the course of walking axial loading is the share of not changed fibular bone, edges over time is kompensatorno thickened, sometimes to the sizes tibial since assumes its function.

Artificial S. by operational destruction of a metaepiphyseal rostkovy cartilage of a pla of its part in some cases try to stop growth of a bone at acromegalias (see).

Bibliography: Bogdanov F. R. and Antonyuk I. G. About surgical treatment of patients with the complicated nearthroses and defects of a tibial bone, Ortop. and travmat., No. 3, page 9, 1965; Bukhna A. F. Damages of epiphyseal zones of bones at children, M., 1973, bibliogr.; Lagunova I. G. Radioanatomy of a skeleton, page 22, 286, M., 1981; Maykova-Stroganov V. S. and Rokhlin D. G. Bones and joints in the x-ray image, the Extremity, page 71, etc., D., 1957; Rokhlin D. G. Rent-genoosteologiya and X-ray anthropology, p.1, L., 1936; Green W. T. a. M i-t and 1 M. of A. Congenital radio-ulnar synostosis, surgical treatment, J. Bone Jt Surg., v. 61-A, p. 738, 1979; Weinberg H. o. Early fibular bypass procedures (tibiofibular synostosis) for massive bone loss in war injuries, J. Trauma, v. 19, p. 177, 1979.

In, F. Pozharisky.