Osteosynthesis on the pelvic limb in a fracture of the femur in a dog. Osteosynthesis in animals

For the treatment of fractures, the use of an immobilizing bandage (gypsum) has traditionally been used, this method of treatment has a number of disadvantages - the development of atrophy of the muscles of the limb, frequent malunion of bones, the formation of bedsores under the bandage, impaired blood supply to bones and soft tissues. All these complications led to the abandonment of the widespread use of gypsum for the treatment of fractures, so now this treatment method is used only for the treatment of cracks. A more modern method of treating fractures is osteosynthesis- surgery for surgical comparison of bone fragments with the use of fixing metal structures.

Types of osteosynthesis:

1. Intramedullary osteosynthesis - used to treat fractures of long bones. With this method, a special pin or needle is installed inside the bone. But there are limitations to this method - for example, it is not suitable for the treatment of fractures of the pelvis, skull, spine, jaw, as well as for the treatment of comminuted fractures.

ferret hip fracture

The use of intramedullary osteosynthesis for hip fracture

2. Bone osteosynthesis - with this method, a metal plate is attached to the bones with the help of special bolts. As a result, good stabilization of bone fragments is achieved. This method can treat not only fractures of tubular bones, but also injuries of the pelvis, skull, spine, scapula, etc. The negative side of this method is the rather high cost of the operation, associated with the use of expensive materials (plates, bolts and special tools).

Fracture of the forearm in a dog

Bone osteosynthesis

Gunshot wound to the lower jaw with a fracture of both branches of the lower jaw

View after osteosynthesis

3. Extrafocal osteosynthesis - is used to treat not only fractures, but also dislocations, and consists in passing the spokes through the bone above and below the fracture site with their subsequent fixation from the outside with a special polymer. The advantages of this method are the relative cheapness of consumables, the speed of the operation, and the reliability of fixing debris. The disadvantage of this method is the impossibility of applying an external fixation device in large and giant breeds of dogs.

X-ray after extrafocal osteosynthesis

4. Combined osteosynthesis - consists in the use of several of the above methods and is used mainly for complex comminuted fractures.

A cat with a compound comminuted fracture of the femur

Cat after combined osteosynthesis

Intercondylar fracture of the humerus in a dog

After osteosynthesis

Separately, it is worth considering fractures of the pelvis. As a rule, such injuries are received by dogs as a result of car accidents, and cats by falling from a great height. In case of damage to the pelvic bones, fractures are usually multiple, which makes them the most difficult in the practice of a traumatologist.

Multiple pelvic fractures in a dog. On the right - a fracture of the pubic and ischial bones, on the left - a fracture of the acetabulum.

The same dog after osteosynthesis

Use of a compression plate for a complex fracture of the acetabulum

Our veterinary clinic has accumulated extensive experience in the use of all types of osteosynthesis in animals of all sizes, which allows us to approach the treatment of each case individually and recommend the most optimal method of reconstructive surgery.

Prices, rub.

The price does not include consumables and additional work

Question answer

Is it possible to fix an old fracture (the radius of the front right paw in a dog)? If so, what is the name of this operation? A week later, we were booked in for an examination and an x-ray of an old fracture, we are waiting for what they say. But I would also like to get an answer to the question above ... The fracture has grown together crookedly, the dog is from the street. Julia

Q: Is it possible to fix an old fracture in a dog?

Hello! Maybe. This is metal osteosynthesis. But the only way to tell for sure is from the picture.

Hello. Tell me the approximate amount of total expenses, including additional ones, for prosthetics of the cat's paw. Amputated as a result of falling into a trap, in the area of ​​​​the wrist.

Question: Can you tell me the approximate amount for prosthetics for a cat's paw?

Hello! For prosthetics please email us. [email protected] with a note to Sergey Sergeevich Gorshkov. It needs to be reviewed and reviewed. On the offhand, no one will say the approximate cost.

Under the current conditions of dynamically developing veterinary medicine, it has become important to treat bone fractures in dogs and cats using various methods of osteosynthesis.

What is osteosynthesis

Osteosynthesis (from the Greek Osteon - bone + synthesis - connection). In essence, this is the treatment of fractures using various methods and methods of fixing bone fragments. During the operation, the veterinarian seeks to connect the fragments in such a way as to obtain an anatomically correct bone while maintaining its properties and functions. Osteosynthesis must be stable and functional. The main condition for the successful treatment of fractures in dogs and cats is the functionality of the injured limb. The animal must start using the limb for the first time 24 hours after surgery.

To date, the use of plaster casts and splints is contraindicated due to the large number of complications and due to the low efficiency of these immobilization methods. Plaster casts and splints interfere with the normal function of the limb. As a result, contracture and muscle atrophy, trophic disorders appear. All this creates conditions that prevent the union of the fracture.

In our veterinary clinic, we perform various types of osteosynthesis:

1. Submersible osteosynthesis - the connection of bone fragments occurs with the help of fixators (screws, knitting needles, plates, wire) that are located directly in the fracture zone. Such osteosynthesis, depending on the location of the implants, can be:
   • extraosseous
   • intraosseous
   • transosseous
   • combined
2. External osteosynthesis - when a doctor uses various distraction-compression devices for external fixation to connect bone fragments.

Indications for osteosynthesis in animals

Osteosynthesis for dogs and cats is indicated for fractures that will not grow together without additional fixation, or their union will be incorrect and lead to a violation of functional indicators.

Contraindications for osteosynthesis in dogs and cats

An absolute contraindication is a pathological fracture resulting from an oncological process. The general serious condition of the patient, requiring stabilization. Contraindications directly to internal osteosynthesis is an open fracture with contamination of the surrounding soft tissues, the presence of an infectious process at the fracture site.

Postoperative treatment and rehabilitation

After the operation in our clinic, patients are prescribed a course of antibiotic therapy. External processing of seams. Repeated doses every 14 days. A special rehabilitation course is usually required only for animals with a flight injury, or for patients with concomitant damage to the central or peripheral nervous systems.

As with humans, fractures in dogs and cats are not uncommon. Treatment of fractures in animals is comparable in complexity to that in humans, and is often much more complex and comparable in complexity to pediatric traumatology.

There are a huge number of different types of fractures, and each type requires a different approach.

Types of fractures

A bone fracture can have a very complex name (diagnosis), such as "open comminuted fracture of the right condyle of the femur." This name is associated with a complex classification of fractures.

When broken, parts of the broken bone are called fragments.

If the fragments have not shifted relative to each other after the fracture, then this is a fracture without displacement. If they have shifted in any direction, then this is a fracture with a displacement.

A type of fracture without displacement - crack, microfracture of the bone. With such a fracture, the fragments are not only not displaced, but the fracture itself is not visible on a regular x-ray. Such a fracture is a time bomb, it can grow together, or it can finally break or, in the worst case, become a constant source of inflammation and pain. Computed tomography is required to diagnose these fractures.

If sharp fragments, after displacement, pierced the surrounding muscles and skin and came out, then this open fracture, if the skin is not damaged, then such a fracture closed.

If the fragments broke obliquely, then the fracture oblique, If the fragments broke at an angle of 90 degrees, then straight(the easiest option), if the fragments broke in a spiral, then spiral fracture.

If small fragments are formed during the fracture, then such a fracture is called splintered.

The middle of a bone is called the diaphysis, and the end of the bone that meets another bone at a joint is called the epiphysis. If the bone is broken in the middle, then it is a fracture. diaphyseal. If the bone is broken at either end, then such a fracture is called epiphyseal.

Type of epiphyseal fracture articular fracture. With such a fracture, the epiphysis is broken inside the joint, and not only the bone and surrounding muscles are damaged, but also the joint, which significantly worsens the condition of the dog and can result in permanent lameness and arthrosis of the joint.

There are many types of articular fracture.

Detachments. There are separations of muscles from the bone or breaks of pieces of bone to which the muscle is attached.

Condylar fractures in which half of the articular surface (condyle) breaks off.

In complex joints, which are formed by several bones, one bone can break and the other is not damaged. it incomplete fracture.

If there is only one fracture of the bone, then this simple fracture. If there are several fractures of one bone or the fracture is inside the joint, then such a fracture difficult. Difficult because the treatment of such a fracture requires more experience and knowledge of the doctor, and the operation is long in time.

After reading these classifications (which are far from all listed), one might think that anything and in any way can break down in an animal in accordance with the classification.

In real life, things are a little different. There are statistics and according to her data, animals break only a few bones in 70% of cases, the remaining 30% are rare.

Most often, cats and dogs break their paws, then the spine, and finally the bones of the skull.

If you take paws, then large bones and major joints break first of all.

If it's front paws, then it's

• fractures of the radius and ulna
• fractures of the radius and ulna and elbow joint

• humerus fractures
• fractures of the humerus and shoulder joint

even more rarely fractures in the wrist and metacarpus

If it's the hind legs, then

• femur fractures
• knee fractures
• fractures of the knee and femur
• fractures of the knee and tibia
• tibial fractures

• hip fractures
• pelvic fractures
• pelvic and hip fractures

even less often fractures in the area of ​​the tarsus and metatarsus

In terms of fractures in the head area, the lower jaw leads.

In fractures of the spine, most often break

• first cervical vertebrae
• lumbar spine
• sacral spine
• thoracic spine

Working constantly with the same type of cases, the orthopedic veterinarian studies specific types of fractures in relation to certain bones or joints, studies specific methods for treating such fractures, and has a huge advantage over the general surgeon in the treatment of fractures in animals.

For a veterinary orthopedist, classifications and methods of treatment in relation to a specific joint, and not to a generalized concept of a bone or joint, come to the fore.

Incomplete fracture of a long tubular bone (greenstick)

Treatment of fractures in dogs and cats

The animal is examined by a doctor, if the cat or dog is in a condition that does not threaten their life, a diagnosis of the fracture (X-rays and, in some cases, computed tomography) is carried out, and the fracture is treated (osteosynthesis).

Osteosynthesis - (ancient Greek ὀστέον - bone; σύνθεσις - connection) is a surgical operation to connect bone fragments using various fixing structures that ensure stable fixation of fragments in the correct position.

If there is a threat to the life of the patient, then such a patient is first "stabilized", no matter how much time it takes, and then the diagnosis of fractures and osteosynthesis is carried out.

Anesthesia plays an important role in the treatment of animals with fractures, especially severely injured animals. Without anesthesia, the animal may die from shock or simply suffer from severe pain.

The choice of the osteosynthesis method plays a very important role. The rate of fracture healing and recovery of the animal depends on how correctly the method is chosen.

When choosing a method, the materials used during the operation are also important. For example, a bone can be connected with a plate, but the plates, due to the large surface of contact with the bone, slow down the formation of callus. The imposition of the plate is a factor in slowing down the union. But there are plates made of very strong materials, which are smaller than conventional ones and have limited contact with the bone due to a specially designed rolling profile. Such plates do not affect the healing rate.

When performing osteosynthesis, the main task is to match the fragments as anatomically correctly as possible and fix them in this position 100% immobile. This is the only way to achieve the fastest healing of the fracture.

The second task facing the orthopedic surgeon is to perform the operation quickly and minimally traumatically. The speed is ensured by experience and clear planning of the course of the operation, as well as the chosen method of osteosynthesis.
It is important, during the operation, not to damage the nerves and blood vessels in the surrounding tissues. Their damage can lead to the loss of the paw.

A person is often put in a cast, an animal never. This is an unshakable rule that is constantly violated by general surgeons.

Plastering a dog or cat results in:

A. GYPSUM - MOBILITY OF FRAGMENTS - FALSE JOINT - TREATMENT FOR YEARS - RADICAL RECOVERY SURGERY - FREQUENTLY EUTHANASIA

The imposition of plaster on a dog or cat leads to the mobility of the fracture, its long-term non-union and the formation of a false joint. A plaster cast cannot tightly fix the short small and often crooked (unlike human) bones of cats and dogs. Dogs and cats cannot lie down and wait for the fusion, they want to run and loosen the already unreliable plaster cast. The bones at the fracture site are constantly moving and do not allow the formation of callus (fracture union). If the bones are constantly moving at the fracture site, then they “grind” to each other, cartilage is formed at their ends and a false joint occurs. Such a fracture may not grow together for years.

B. GYPSUM - NECROSIS (DEATHING) OF THE PAWS TISSUES - REMOVAL OF THE PAWS - OFTEN EUTANASIUM

Casting a dog or cat results in necrosis (death of the paw) and loss of the paw (removal).
Or to inflammation of the paw, suppuration, long-term treatment and removal of the paw in extreme cases.
People often euthanize animals because they are not ready to take care of a disabled animal.

C. GYPSUM - SEVERE DERMATITIS UNDER GYPSUM - SUPPRESSION - SKIN PLASTY - RADICAL RECOVERY SURGERY - FREQUENTLY LOSS OF PAWS AND EUTHANASIS

Casting is always accompanied by severe dermatitis of the skin under the cast (wool, moisture and dirt cannot simply be preserved under a cast, they destroy the skin and paw under the cast). This is followed by a long recovery of the skin, plastic, antibiotic treatment and a complex reconstructive operation.
People often despair and euthanize animals, because they are not ready to pay for a complex operation to restore a paw, they are not ready to take care of a cripple animal.

THUS, GYPSUM IN 99% OF CASES LEADS TO COMPLICATIONS AND RECOVERY SURGERY WITH A LOWER PROBABILITY OF COMPLETE RECOVERY OF THE PAWS.

60% of the work of orthopedists, plastic surgeons in our clinic is made up of alterations and retreatment after unsuccessful osteosynthesis and plastering at home and in conditions close to those of military field surgery (but these dogs were not on the battlefield), by doctors who do not have experience and knowledge to carry out such operations and do not have the necessary tools and consumables.

Features in the treatment of spinal fractures

The only difference is time.

The spinal cord and nerves can be destroyed irreversibly and the animal will remain disabled.

Time is not playing into your hands.

If the spine is damaged, there is a possibility of damage to the spinal cord by bone fragments and displaced vertebral bodies. The sooner the load on the spinal cord is removed, the faster the spinal cord will begin to recover and the less likely that irreversible damage to the spinal cord will occur.

Care after surgery

Care for a recovering pet depends on the type of fracture and the type of surgery that has been performed. Although most pets can be allowed to do some exercise almost immediately after surgery, it is important that unrestricted activity such as running or jumping is avoided. Sometimes it is required to keep a pet in a limited area, for example, in a small room. Physiotherapy and hydrotherapy may be recommended as part of a recovery program. In most cases, we re-examine the pet six to eight weeks after surgery. When x-rays show that the fracture has healed, normal activity can be resumed.

Risks and difficulties associated with the treatment of fractures

Even an operation performed flawlessly can carry the risk of certain complications such as infection and difficulty in bone healing. However, if the operation is performed by an experienced specialist, such complications are rare, and most pets recover without complications. Joint fractures can lead to osteoarthritis, which may require long-term follow-up with a doctor, however, most pets do not experience such complications. Before any treatment is started, all aspects of your pet's postoperative care, including the risk of complications, will be detailed during your initial consultation with the orthopedist.

prospects

Most pets gain full use of their limbs and can enjoy a normal life.

Why should you contact us for the treatment of a fracture in your pet?

• We have extensive experience in the successful treatment of various fractures;
• We are attentive to each patient;
• We use modern technologies and methods of treatment;
• Our experts regularly take part in veterinary conferences;

The femur is one of the strongest in the body, so its fracture can occur only with serious injuries or pathologies. Main symptoms: pain, inability to stand on the injured leg. A hip fracture in a dog needs surgical treatment.

The femur is long tubular, the upper end has a spherical head and is involved in the formation of a multiaxial hip joint, reinforced by an intracapsular round ligament.

The lower end of the thigh has two rounded blocks to form the femoral and tibial joints.

The upper end of the thigh, in addition to the head with a hole under it (for attaching the round ligament), has a neck, large and small skewers for attaching the gluteal muscle group. Therefore, in Perthes disease, a fracture of the femoral neck is more often observed, as places with the greatest load. The trochanters are connected by an intertrochanteric ridge, which creates the boundaries of the trochanteric fossa.

The lower end of the femur has two ridges of the same size for the patella, between which there is a groove for it to slide during movement. The lower end ends with two condyles - rounded elevations for attaching the tibia. Between them is the intercondylar fossa.

Causes of hip fracture

According to the etiology, fractures can be divided into two large groups: traumatic and pathological.

The causes of traumatic fractures are varied:

• falling from height;
• road accident, car collision;
• a fight with a larger dog;
• a blow from a person;
• and others.

Several diseases lead to pathological fractures:

• Perthes disease. As a result, a hip fracture is commonly seen in small breeds;
• oncology. It is more often registered at old dogs;
• alimentary hyperparathyroidism. Can be found in puppies with protein feeding.

Types of hip fractures

In addition to classification for reasons, there is a division according to the type of fracture:

• Incomplete fracture - a crack in the bone. In this case, the bone still remains a single whole, the crack affects only part of its surface. This is the mildest form of hip injury, but quite dangerous, as it can develop into a real fracture at any time.
• Impacted fracture. It happens when the load is directed not across the bone, but along. For example, when an animal jumps from too high a height. In this case, one fragment enters another. A fairly complex type of fracture, since it requires the extraction of one end of the bone from the other, but it rarely occurs in the femur. Despite the self-fixation of the bone, the dog is not able to lean on the injured limb.
• Fracture without bone displacement. Despite the injury, the fragments do not move relative to each other, so the surrounding tissues are not damaged.
• Closed fracture with displacement. The most common type of fracture. Fragments of bones damage the surrounding tissues, resulting in a hematoma or edema. This type of injury is dangerous with internal hemorrhage, especially if large vessels of the thigh are damaged.
• Open fracture. In this case, a piece of bone breaks through the muscles, skin and comes out. In this case, the injury is often complicated by an infection that penetrates through the resulting wound, so the fracture requires urgent surgery.
• Multiple fracture (with splinters). The most complex type, requiring a long and difficult operation, during which the bone is collected piece by piece. Often, along with such a fracture, other damage to the internal systems (vessels, nerves) or open wounds are also observed. This type of injury often has severe consequences for the dog.

Symptoms and first aid

The most common symptom is severe pain. She does not allow the dog to lean on the limb. When trying to feel the injured leg, the dog behaves aggressively, it may even bite the owner. When examining a limb, one can see edema, hematoma, and in severe cases, a wound, sometimes with a bone fragment in it. Often, the asymmetry of the hind limb is immediately visible, but sometimes such symptoms are not detected.

Since the dog can behave aggressively, you should immediately put a muzzle on it so that it does not bite the owner or the doctor. The first aid is to fix the limb. To do this, you need to take a long, strong and not flexible stick and tie it to the dog. On the one hand - to the knee, on the other - to the pelvis in the region of the hip joint.

You can not try to set the bone yourself, it will cause an incredibly strong pain reaction.

In addition, you can damage blood vessels and nerves with fragments of bones. The bone should be set by a specialist and only after an X-ray. X-ray is done in two perpendicular planes.

After fixing the limb, you need to deliver the dog to the veterinarian as soon as possible. Large pets are carried on a piece of plywood, a stretched blanket, and other makeshift stretchers. It is not recommended to do anesthesia, as this can lead to incompatibility of the drugs that the doctor will use.

Hip fracture treatment

Treatment at home is impossible, since the condition with fractures is too dangerous. First of all, anesthesia and general anesthesia are carried out, so that the dog allows itself to be examined calmly. Next, an x-ray is taken to determine the position of the bone fragments. Often, in case of fractures, surgery is done immediately.

With incomplete fractures (cracks) or with closed fractures without displacement of the bones, plaster is applied or a splint is created. However, this method is not always effective, because the dog may try to remove the cast, thereby injuring his limb again. In this regard, veterinarians prefer to perform operations.

The operation is done under general anesthesia, all methods of fixation can be divided into two large groups.

Intraosseous osteosynthesis with a pin

The first incision is made at the site of the fracture. Through it, small fragments of bones, blood clots are removed, with an open fracture, they are treated with antibiotics. Next, the upper and lower bone fragments are removed into the wound so that it is convenient to manipulate them.

Then, using a stylet and a drill, a hole is made through the bone fragment near the upper head of the femur. It is made from the inside, through the medullary canal, through the first incision, this is necessary to introduce a conductor - a metal wire that will set the direction of the pin.

The conductor is pushed into the bone through the fracture site to the very top, so that it comes out from the upper end of the bone in the area of ​​​​the vertical cavity (between the head of the bone and the greater and lesser trochanters). When the conductor rests against the skin of the buttock, a second incision is made in this place.

A pin is inserted through the second incision, with the help of a conductor it is given a direction. If necessary, help the pin with a hammer to enter the bone. It is pushed until it comes out of the upper fragment by half a centimeter. After that, the ends of the bones are connected and the pin is inserted completely.

Bone osteosynthesis with rings

If in the first case the pin is inserted into the bone, then according to this method, the fixator is attached from above to the bone. This method is preferred for small breeds, as their bones are thin and do not allow the use intraosseous method. The latch itself can be in the form of a plate, beam or rings.

An incision is made at the fracture site, then the injured area is cleaned of small bone fragments, crushed tissues, and blood clots. The retainer is attached using screws, rings, spokes and other devices. It all depends on the type of fixing device.

Further rehabilitation

Further care includes rest, restriction of movement for the first week. The dog itself will determine the time when you can lean on the paw. On the third day, a callus is formed between the bone fragments, consisting of cartilage tissue, which begins to ossify after 8-10 days. Complete fusion of the bone occurs in 25-45 days.

From the book "Diseases of the Skeletal System of Animals"
Lukyanovsky V. A. and others. Kolos Publishing House, 1984

At closed fractures animals are given first aid. It is necessary to limit the movement and displacement of bone fragments, which can injure muscles, damage blood vessels and nerves, and also cause a strong pain reaction. In addition, it is necessary to prevent the transition of a closed fracture into an open one due to possible damage and rupture of the skin by broken bone fragments, for which a temporary immobilizing bandage is applied and the animal is given complete rest.

When open fractures perform surgical treatment of the wound. It is freed from contamination, foreign objects, dead tissues are removed, the area around the wound is treated with 5% tincture of iodine and covered with a napkin, and then immobilized. To do this, use tire bandages made of plywood, thin planks, splint, wire rods, tin or plastic strips, etc. Special metal tires are also used. In order to prevent the formation of bedsores in the bandage area, soft lining material or layers of gray cotton are used, which are applied to the affected surface under the splint.

Immobilizing splint bandage provides the necessary fixation for fractures in the event that it blocks the mobility of the joints above and below the fracture site of a particular bone.

Depending on the nature of the fracture, the type of animal, the anatomical topographic location of a particular bone and other conditions, the treatment of bone fractures can be conservative or operative. It includes non-bloody and bloody methods of joining fragments, as well as methods and means that stimulate the formation of callus and, in general, osteogenesis, consolidation of fragments.

Conservative treatment of closed bone fractures involves the reduction of displaced fragments and their immobilization, the creation of good conditions for regeneration and stimulation of fracture healing. It should be borne in mind that in advanced cases of bone fragments, it is very difficult to set. Therefore, it is necessary to ensure the greatest possible relaxation of the muscles through anesthesia and local anesthesia.

A good connection of adjacent bone fragments after reduction is achieved by applying immobilizing bandage. It may be different. However, with any dressing, the main thing is to ensure the suction of the wound discharge and reliable antiseptics. The bandage is removed in young large animals on the 35-40th day, in small animals - on the 20-25th day, i.e., during the period of restoration of the supporting function of the injured limb, in old ones - a week later.

The conservative treatment of tubular bone fractures in animals has advantages and disadvantages. An immobilizing bandage, squeezing the tissues for a long time, makes it difficult to restore impaired blood and lymph circulation, resulting in the development of congestion. In addition, fixation of the joints with a bandage excludes the injured limb from the functional load, and this leads to a delay in the formation of callus and other complications.

At open fractures it is necessary to toilet the wound, treat it with tincture of iodine, complex powders and apply a protective immobilizing bandage. In case of complications, a hole (window) is made in such a bandage. This makes it possible to systematically treat the wound and constantly monitor the nature of the healing of the fracture. In case of severe contamination of the wound and significant traumatization of the surrounding tissues, a complex of intensive antiseptic therapy is carried out.

Operative treatment. The operation of connecting bone fragments in a bloody way is called osteosynthesis. Indications for its implementation are open and closed fractures of the olecranon and calcaneal processes, femur, humerus, metacarpal, metatarsal bones in small animals and the lower jaw in large and small animals, as well as fractures of the radius and tibia in large animals.

To connect fragments, metal sutures, aluminum, brass, nickel, molybdenum, and copper wires with a diameter of 0.6-1 mm or more, stainless needles, nails, screws, plates, brackets, bone grafts, metal splints, wooden for intramedullary osteosynthesis are used, metal pins. Recently, polymer pins, strong adhesives, and ultrasonic surfacing and bone welding have been developed and successfully introduced.

With closed fractures, osteosynthesis should be done a day after the injury. At a later date, it is difficult to carry out traction and reposition of fragments. With open fractures, osteosynthesis should be done as early as possible in order to prevent the development of microflora.

Connection of fragments with a wire bus used for fractures of the body of the lower jaw. To do this, the so-called intraoral splint (wire ligature), after appropriate surgical treatment for open fractures, connect bone fragments. In large animals, a wire 2 mm thick is used. In case of metaphyseal fractures, the bones are fixed with two wire ligatures: one is applied around the lateral incisors with hooks, and the other around all incisor teeth. In case of transverse oblique fractures of the body of the lower jaw in male horses, the fragments are fixed by connecting the canines and the edges of the corresponding side of the jaw (see Fractures of the lower jaw).

The bone suture is carried out with a wire, passing it through holes made in the bone. The ends of the wire are twisted with pliers until the fragments are firmly connected. A bone suture is used for oblique or spiral fractures of tubular bones and fractures of the horizontal branches of the lower jaw. However, as noted by B. M. Olivkov (1949), the connection of the bones of the lower jaw with a bone wire suture should be performed only in extreme cases, where it is impossible to impose an intraoral wire splint, since passing through the holes of the wire causes an exacerbation of inflammatory processes in the bones, delays callus formation, and sometimes causes necrosis and other pathological changes.

Fixation of bone fragments with steel staples, which was previously used for fractures of the femur in dogs, has now been successfully replaced by intramedullary osteosynthesis with pins of plant, metal or polymer origin. In some cases, this method can be used to attach fragments of the calcaneus in horses. To do this, triangular or U-shaped stainless steel brackets are made of the required size according to the x-ray and used to fix the calcaneal tubercle by the following method. The fracture zone is not previously opened, the ends of the brackets are carefully driven into the drilled holes in the bone.

Joining bone fragments with nails. Fragments are connected with oblique, longitudinal or spiral fractures of tubular bones and fractures of the femoral neck. To do this, a nickel-plated nail is driven into the drilled hole with light blows of a hammer perpendicular to the direction of the fracture line.

Connection of bone fragments with screws (screws). Nickel-plated screws are used for fractures of the ulnar and calcaneal tubercles, maklok and greater trochanter of the femur, and also sometimes for metaphyseal fractures of tubular bones. To do this, use two drills of different diameters. A drill close to the diameter of the screw neck (but somewhat smaller) is used to drill a broken bone section, and a drill with a diameter smaller by 1-2 mm than the middle part of the screw body is used to drill the body of the bone to which the fragment will be fixed. This method makes it possible to very firmly and reliably connect the fracture and does not cause a split of the bones. After the operation, a fixing bandage is applied, if possible. The screw is removed through a new skin incision after 35-45 days.

Connection of fragments with metal plates used for various fractures. For this purpose, strong inflexible plates and screws are used. Through holes in the plate and symmetrical holes in the bone, the fracture is connected with screws. Plates and screws must be made of a homogeneous metal. Otherwise, in the tissue fluid, one of the electrodes will “corrode” and corrode.

The plates are not removed until the fractures are completely healed. If lameness, secondary osteitis or fistulas appear in the operated area after 3-4 weeks, the plates are removed.

Distraction splints. Such tires have been very successfully used in medical practice in recent years. In veterinary medicine, they are used in exceptional cases: with comminuted fractures and large discrepancies in length of fragments, to prevent shortening of the limb.

Distraction splints allow you to combine osteosynthesis with traction. To do this, take two knitting needles with screw threads and two metal plates with holes. The pins are inserted through the drilled holes into the distal and proximal fragments, and the plates are put on the free ends of the pins from the outer and inner sides of the limb. The correct reposition of fragments is carried out with the help of plates by lengthening the distance between the ends of the spokes. Such splints allow for the necessary period of fixation of bone fragments after their reduction.

The imposition of distraction splints must necessarily be accompanied by the use of a splint bandage. The latter is removed simultaneously with distraction splints after 20-30 days, depending on the nature of the fracture healing.

Intramedullary osteosynthesis with a metal pin. The operation is related to the exact choice of the pin. To do this, x-rays are taken. The operation is done as early as possible. With an increase in the general body temperature, to suppress the development of microflora, it is necessary to use antibiotics (introduced into the extravasate and intramuscularly), and then, after improving the general condition, they proceed to the operation.

Over the past 20 years, metal pins have become widely used in veterinary surgery. This is a lamellar pin made of stainless steel for small animals (G. A. Mikhalsky, 1954) and a grooved pin for large animals (A. D. Belov, M. V. Plakhotin, 1957). Pins, as a rule, are selected according to the radiograph. Its width should correspond to the narrowest part of the medullary canal, and the length may vary depending on the nature of the fracture and the size of the damaged bone. For example, with high fractures, it is not necessary to make a pin in the entire length of the bone. To do this, it is enough that the pin goes into the peripheral fragment by 4-6 cm. In case of low fractures, the length of the pin should be large so that it can be passed to the epiphysis.

The operation is performed both under combined and local anesthesia. In the latter case, a 0.25% aqueous solution of novocaine is infiltrated into the skin, and a 2% solution of novocaine in 30 ° wine alcohol is infiltrated into the soft tissues and bone marrow. Alcohol novocaine should be injected into the medullary canal from the side of the fracture. Sheep and calves are injected with 10-15 ml, small dogs, cats - 5-7 ml.

Osteosynthesis of the femur in large animals(cattle, young animals, sheep, goats, large dogs) is carried out with a pin through two incisions. One incision 7-10 cm long is made over the fracture site. The muscles are not cut, but dissected one from the other (biceps femoris, superficial gluteus and lateral head of the quadriceps femoris). After that, blood clots, bone fragments, crushed tissues are removed and alcohol-novocaine is injected into the bone canal. Then the wound is closed with a sterile napkin and a second incision 4-5 cm long is made above the greater trochanter.

The superficial gluteal muscle is retracted forward with a wound hook, thereby opening access to the bottom of the acetabulum. A hole in the medullary canal is drilled from the side of the acetabulum. The hole can also be made with a trocar from the side of the medullary cavity. The pin is inserted into the upper fragment until its end goes beyond the fracture line by 0.5-1 cm, the ends of the fragments are brought closer to each other at an obtuse angle and, by directing the end of the pin into the medullary canal of the distal fragment, the latter is given the correct axial position. Only after that, with light blows of the hammer, the pin is advanced into the medullary canal of the distal fragment. The operation is completed by dusting with a complex antiseptic powder, the wound is closed with a two-story suture and a protective coating or a light cotton-colloid dressing (Fig. 59).

Rice. Fig. 59. Scheme of introducing a metal pin into the medullary canal (Surgical clinic MVA, according to A. D. Belov): A - hips; B - shoulder.

In case of fractures of the femur in small animals (small dogs, cats) and fractures in the upper third of the diaphysis in sheep, goats and large dogs, the operation is performed through one incision, starting 3-5 cm above the greater trochanter and ending 3-5 cm below fracture line locations. Surgical access for fractures of the humerus in all types of animals is made through one incision from the lateral side along this bone.

The incision starts 5-7 cm above the fracture and ends 2-3 cm below it. Then, the muscles are bluntly separated, alcohol-novocaine is injected into the medullary canal, and only after that, a hole is drilled at an angle of 45-50° to insert a pin on the lateral surface of the proximal fragment 3-5 cm above the fracture line. To give the pin the correct direction, the upper edge of the hole is cut off in the form of a groove. The correct reposition of the fragments and the insertion of the pin is carried out in the same way as in the case of fractures of the femur.

At osteosynthesis of the tibia and radius one incision is also made on the medial surface of the lower leg and forearm (the operation technique is the same as for a fracture of the humerus). After fastening the bone with a pin, a blind suture and a light protective bandage are applied to the surgical wound. Additional immobilization is not required.

Strong fixation of fragments provides a free position of the joints and allows the animal to include the limb in the functional load in a short time after the operation. This prevents contractures and muscle atrophy, to a certain extent normalizes blood and lymph circulation in damaged tissues, and significantly accelerates the formation of callus and fracture healing.

Consolidation of the fracture is established clinically and radiographically, the pin is removed under local anesthesia. To do this, the pin head is probed through the skin and an incision 2-3 cm long is made above it.

A hook is inserted into the head hole and the pin is either removed freely or with light blows of a hammer. The postoperative wound is closed by conventional methods. The pin, under good healing conditions, is removed at the following times: in cattle, sheep, goats and pigs on the 25-30th day, in dogs and cats on the 35-45th day.

Recently, a promising method of osteosynthesis with a polymeric absorbable pin deserves to be used (M. V. Plakhotin, L. Ya. Loktionova, V. A. Lukyanovsky, Yu. I. Filippov, N. I. Ochirov et al., 1973). Such a pin is a rod with four longitudinal stiffeners. It is made from a biodegradable copolymer of vinyl nitrogen-containing monomer with acrylate, reinforced with absorbable polymer fiber. The pin diameter is 5-14 mm in 1 mm intervals and the length is 250-420 mm, depending on the pin diameter. They are sterilized either by irradiation with a dose of 2.5 billion and sent to consumers in sterile packaging, or by keeping them in steam for 24 hours.

Intramedullary osteosynthesis absorbable polymer pin is recommended for diaphyseal fractures of the tibia, femur and humerus in dogs, cats, sheep, foxes and other small animals. After dissection of the soft tissues above the fracture zone and removal of fragments from the wound, the medullary canal is drilled from the side of the fracture with a drill with a T-handle and a diameter corresponding to the cross section of the pin.

In the upper fragment, the same drill through the medullary canal makes a hole in the bone to pass the pin from above (in the femur in the region of the acetabular fossa, in the tibia - above the lateral crest, in the humerus - above the external tubercle). The length of the pin is determined by the depth of the medullary canal, the pin is adjusted and cut with a scalpel. To avoid defibration, it is cut at an angle of 30-45° with respect to the axis of the pin.

A pin is inserted from the side of the fracture into the upper bone fragment until it exits under the skin, then an incision is made above it and brought up into the wound until the end of its fracture remains protruding by 1 cm. Then the fragments are connected and the pin is pushed through the bone marrow with light hammer blows. channel into the lower fragment for the entire length. In order to exclude the possible disintegration of the pin during a blow with a hammer when it is inserted into the medullary canal, special metal nozzles are used, the inner diameter of which must correspond to the diameter of the pin.

Intramedullary osteosynthesis with a polymer pin was carried out in the surgical clinic of the Department of General and Private Surgery of the Moscow Veterinary Academy on dogs and sheep with experimental fractures of the diaphyseal tibia and femur. In the postoperative period, the animals felt satisfactorily, the general condition returned to normal on the 3rd-7th day, clinical indicators approached the initial ones after 2 weeks. The function of the injured limb in most animals fully recovered after 4-5 weeks (with the correct restoration of the long axis of the bone). In some dogs and sheep, due to some displacement of fragments, the bone has fused at a slight angle.

It was established that in the process of fracture healing, the polymeric absorbable pin gradually swelled and loosened fibers. It began in the area of ​​fragments connection and then spread along the pin located in the medullary canal. The period of resorption of the pin is 1.5-2 years.

The polymeric absorbable nail, when administered intramedullary, is non-toxic, does not cause a pronounced reaction in the body to a foreign body, and provides immobilization of bone fragments in case of fractures of the tibia and femur in dogs and sheep. The use of a polymeric absorbable post eliminates the secondary operation, which is mandatory in cases where a metal post is used.

ULTRASONIC WELDING AND WELDING OF BONE TISSUE

Ultrasound is now increasingly used in medicine and veterinary medicine for therapeutic and diagnostic purposes. In case of bone injuries, it is used for surfacing and welding of injured bones. In medicine, extensive research has been carried out to find the most rational methods for ultrasonic welding of bones. In veterinary medicine, at the Department of General and Private Surgery of the Moscow Veterinary Academy, since 1973, in creative collaboration with the Department of Welding of the Moscow Higher Technical School named after N.E. Bauman, research has been carried out on optimal options for ultrasonic surfacing.

To date, experimental studies have established the specific features of the replacement of ultrasonic surfacing with bone regenerate in tubular bones in sheep and dogs in the process of bone tissue regeneration after experimental defection. In the experiments, 20 sheep and 19 dogs were used, in which a rectangular bone plate of the diaphysis 12–20 mm long and 4–5 mm wide was sawn out by ultrasound or mechanically in the region of the radius and tibia. In some cases, the bone marrow was removed in the defect zone, in others it was preserved.

The bone defect dried with sterile gauze drains was filled with bone chips to the outer edges. Porous surfacing was obtained by exposing bone chips to ethyl a-cyanoacrylate, as well as adding 5% ethoxyethyl cyanoacrylate or arotic acid to it, dense surfacing was obtained by using heterochips in dextran with exposure to ethyl a-cyanoacrylate.

In all cases, the polymerization of the surfacing was carried out with an ultrasonic device for 15-20 s at an oscillation frequency of 26.5 kHz, an amplitude of 50-55 μm (Fig. 60). Subsequently, after dusting with antiseptic powders, ordinary sutures were applied to the surgical wound and covered with an antiseptic dressing (sometimes plaster).

In the postoperative period, the general condition, pulse rate, respiration, temperature was measured in animals, histological and biochemical blood tests were performed (total protein, protein fractions, Ca and P). On the 15-20th, 30th, 40th, 50th, 60th, 80th, 100th, 120th, 140th, 160th, 180th and 200th days after ultrasonic surfacing, the pathological material was taken and pathological, radiological, biochemical and histological studies were performed. It was established that the general condition of the animals during the experiments was satisfactory in all cases. In the first 2-3 days after the operation, both in sheep and dogs, the body temperature increased, breathing and pulse quickened to the maximum physiological norm or slightly higher. During the first 5 days mild lameness was observed. Wound healing proceeded by primary intention. Bandage dressings and sutures were removed on the 10-12th day after the operation of ultrasonic welding.

It was noted that the reaction to ultrasonic surfacing of bone defects in both sheep and dogs is close to the usual reaction to surgical bone trauma.

According to X-ray studies, the periosteal reaction after surfacing manifests itself on the 17-20th day. Endosteal reaction with porous surfacing appears on X-ray patterns on the 25-30th day, and with dense surfacing - on the 40-50th day. In subsequent periods, until the complete replacement of the surfacing with bone regenerate, the periosteal and endosteal reactions are more pronounced.

Until the 40th-60th day, according to X-ray data, the difference in the development of the postoperative reaction in the surfacing zone in sheep and dogs cannot be established. It should be noted that during these periods the contours of the defect are expressed quite clearly, and a light gray shadow is formed in the surfacing zone on X-ray photographs, which indicates the development of regenerative-restorative processes.

By day 80, the occlusion of the medullary canal was noted proximal and distal to the surfacing zone as a result of endosteal formation of bone tissue. On radiographs, this was revealed in the form of dense gray shadows. This reaction in sheep and dogs is most pronounced when the bone marrow is removed. During these periods, the contours of the defect are less noticeable, the defect zone in sheep on radiographs is darker than in dogs.

In sheep, the contours of the defect by 100-110 days are poorly visible, the bone regenerate at the site of the defect is clearly marked, the density of which, in terms of the intensity of the shadow, approaches the density of the intact bone tube. Such a radiograph was established in dogs at 20-30 days. later (on, fig. 30).

Clinical and radiological studies have noted that in sheep and dogs, the defect is completely replaced by bone regenerate at different times. So, in sheep with porous surfacing, this occurred by 140-160 days, in dogs - later than 180 days, with dense ones, respectively, by 110-120 and 160-180 days. With dense surfacing with preservation of the bone marrow after the operation, the medullary canal acquires the shape of a regular tube, and the tubular bone in the surfacing zone acquires the correct shape. With porous surfacing, the wall of the tubular bone in the defect zone during these periods is somewhat thickened inside the medullary canal.

It has been established by research that the complete replacement of surfacing with bone regenerate occurs faster in sheep than in dogs, and this difference is most pronounced when using dense surfacings. Thus, ultrasonic devices can be successfully used in clinics for surfacing for defects in various bones in animals.

BIOLOGICAL ESSENCE OF HEALING OF FRACTURES OF BONES
(CLINICAL AND RADIOLOGICAL, HEMATOLOGICAL, BIOCHEMICAL AND RADIOISOTOPE INDICATORS OF HEALING OF FRACTURES OF TUBULAR BONES

The healing of bone fractures is accompanied by both local and general changes in the body. Bone tissue after a fracture is restored by the formation of a bone callus (incl., Fig. 34). The following are involved in the regeneration process: the inner (cambial) layer of the periosteum, endosteum, bone marrow, endothelium of the vessels of the Haversian canals, young connective tissue, subsequently metaplasing into the bone (Fig. 61).

Rice. 61. Rib fractures. Bone formation.

In the primary callus (AD Belov, 1966) there are: periosteal, or external, callus, which develops from the cells of the cambial layer of the periosteum; endosteal, or internal, callus, formed from the cells of the endosteum and bone marrow of both fragments; an intermediate callus developing from the haversian canals of the cortical layer of the bone and partly from the cells of the endosteum and periosteum; parossal, or near-osseous callus, formed from soft tissues near the fracture. The development of this callus depends on the degree of damage to the surrounding tissues.

In the process of formation of callus, the following main phases are distinguished.

First phase- preparatory - within 48-72 hours, in response to injury, serous aseptic inflammation develops, exudation and migration of leukocytes into soft tissues. At the same time, traumatic osteitis occurs at the ends of the fragments. Under the influence of osteoclasts and their enzyme (acid phosphatase), under conditions of local acidosis, demineralization of the ends of the fragments along the fracture line occurs.

Second phase occurs 3 days after injury and is characterized by the formation of connective tissue callus. Initially, osteoid tissue is formed in the cellular elements of the periosteum, endosteum, and bone marrow at some distance from the fracture line, that is, in the intact area from injury, and then this process continues to the fracture line.

At the same time, osteogenic cells of the cambial layer of the periosteum, bone marrow, and endosteum penetrate the blood clot in the fracture zone, gradually multiplying, and grow into it with a dense network of blood capillaries. A kind of granulation tissue develops around the bone fragments, which is a connective tissue callus, where the cellular elements in it, by differentiation, turn into osteoblasts and bone cells, and the intermediate substance - into collagen fibers - the main substance.

This phase is characterized by an increase in the activity of alkaline phosphatase, the intensity of phosphorus-calcium metabolism. In addition, the content of phosphorus and calcium in the blood serum increases, the activity of alkaline phosphatase and the complexing properties of proteins with phosphorus-calcium salts increase.

Third phase. After 10-12 days. a callus is formed, characterized by the process of ossification. For osteoid tissue at this time, the process of ossification is characteristic. The main role here is played by osteoblasts that produce alkaline phosphatase and carbonic acid. The resulting bone tissue does not have a physiologically correct structure. Gradually, with the restoration of the musculoskeletal function, it undergoes a static-dynamic restructuring.

Fourth phase is accompanied by the final restructuring of the formed callus with the regrouping of bone beams according to the laws of statics and dynamics. This process takes a long time. During this time, the bone beams of the callus, which do not function under static-dynamic load, dissolve, and those under load are formed and, in their architectonics, approach normal bone. For general changes in the body, a gradual normalization of biochemical parameters is characteristic, which are established within the normal range after 5-8 months.

The healing of fractures in different animals has its own characteristics. So, horses and dogs after a fracture strictly protect the limb and include it in the support function, when the fragments are firmly fixed by the callus. In these animals, the fracture is accompanied by the development of serous inflammatory edema, the phenomena of proliferation are weakly expressed, the connective tissue callus is formed by 10-15 days. Fragments of the bone grow together by 35-45 days.

Cattle, sheep and pigs spare the injured limb in the first 3-5 days, and then they begin to gradually include it in the supporting function. The zone of inflammatory edema in them is more localized than in horses and dogs, the connective tissue callus is formed by 8-10 days. Bone fragments in these animals grow together by 25-35 days.

Fractures can have complications. The most dangerous are osteomyelitis in open and gunshot fractures, contractures and false joints (pseudoarthrosis). In the latter case, persistent abnormal mobility is noted at the site of the former fracture, which may occur as a result of a violation of the process of callus formation (Fig. 62).

Rice. 62. Scheme of formation of pseudarthrosis:
1 - post-traumatic hemorrhage; fragment diastasis; 2 - formation of connective tissue in a blood clot (inflammatory osteoporosis of bone fragments); 3 - proliferation of bone tissue around fragments (transformation of connective tissue callus into fibrous); 4 - formed pseudarthrosis.

Currently, clinical and radiological, hematological, biochemical, histological, radioisotope and other research methods have established that the body's response to injury is accompanied by significant shifts in the balance of the animal body, a number of local and general disorders, biochemical changes in the blood and bone system, and metabolic disorders. substances both in the area of ​​the injured segment and in the body as a whole.

Studies by domestic and foreign authors, as well as experimental and clinical studies conducted on dogs, sheep, pigs and young cattle at the Department of General and Private Surgery of the Moscow Veterinary Academy (M.V. Plakhotin, G.A. Mikhalsky, R.G. Mustakimov, A.D. Belov, V.A. Lukyanovsky, L.Ya. Loktionova, Yu.I. Filippov, N.I. Ochirov, etc.) have made it possible to more deeply reveal the biological essence of bone fracture healing.

With fractures of tubular bones, significant changes occur both in the fracture zone and in the body as a whole in the first 10 days. This period is characterized by pronounced clinical, biochemical, histological changes. So, after a fracture and osteosynthesis in animals, appetite decreases, body temperature rises, pulse and respiration become more frequent, an inflammatory process occurs locally in the area of ​​damage with more or less pronounced edema.

Against this background, already on the 5th and 10th days, significant changes are observed, accompanied by a decrease in the amount of total protein, albumin, albumin-globulin ratio (A/G) and an increase in the content of inorganic phosphorus in the blood. During this period, the content of inorganic phosphorus at the ends of fragments decreases, which, apparently, is associated with local acidosis, the predominance of acid phosphatase, and an increase in osteoclast activity that occur against the background of an inflammatory reaction. These phenomena are also noted by V. M. Vasyutochkin, E. M. Guseva (1930), N. P. Altshuller, M. N. Pogorelov (1936), M. V. Plakhotin and A. D. Belov (1967), Mohamed -El Mustafa (1963), Z.M. Zelenskaya (1968) and others. It was established that after bone fractures there is a shift in the active reaction of the blood towards acidosis, and subsequently, as acute reactive phenomena weaken, the disappearance of inflammatory edema of soft tissues, the predominance of regenerative processes and the formation of callus, an active reaction of the blood and the tissue environment gradually disappears towards alkalosis. Most authors believe that against the background of acidosis in the bones, the processes of rarefaction and recrystallization prevail, and with moderate alkalosis, condensation and crystallization.

A decrease in the level of mineral metabolism at the ends of fragments and an increase in the content of mineral substances in the blood in the first period after a fracture, apparently, are associated with the resorption of mineral substances from the bone tissue and their entry into the blood.

By the 10th day, the intensity of protein-mineral metabolism in the bone-forming elements of the damaged bone increases, hypoproteinemia increases against the background of an increase in the biosynthesis of alpha- and beta-globulins with a simultaneous predominance of their decay and a strong decrease in the level of albumins. The biosynthesis of gamma globulins exceeds the intensity of their decay, in connection with this, the amount of gamma globulins in the blood serum becomes higher than the original. Radiologically, by this time, light gray shadows of periosteal layers are established at a considerable distance from the fracture site.

Consequently, in the initial period, within 10 days after a fracture of the tubular bones and intramedullary osteosynthesis, acute reactive phenomena occur, accompanied by a pronounced inflammatory reaction, an increase in body temperature, and an increase in heart rate and respiration. This reduces the amount of total protein, albumin, alpha globulins and increases the content of minerals in the blood serum. In the ends of the fragments and the epiphyses of the damaged bone, the level of calcium and phosphorus increases. In the symmetrical areas of the diaphysis and the epiphyses of the intact tubular bone, no significant changes were observed. Radiologically, by this time, light gray shadows are established in the zone of the emerging callus, and a radioisotope study using Ca45, P32 and S35 methionine reveals a fairly high level of protein and mineral metabolism (incl., Fig. 54).

In the period from the 10th to the 25th day, acute reactive phenomena subside and the emerging callus is quite clearly visible on the radiographs. Indicators of the content of total protein are normalized, and the amount of albumin and albumin-globulin index remain at a low level. The enzymatic activity of alkaline phosphatase increases to the maximum. By the end of 25 days, radiographs show the beginning of closing of the periosteal callus of the proximal and distal fragments.

During this period, the content of mineral components significantly increases in the periosteal callus adjacent to the ends of the fragments; and in the callus at the level of the fracture. Moreover, there are more of them in the periosteal callus. The level of mineral substances in the epiphyses slightly increases, while at the ends of the fragments, on the contrary, it decreases. Radioisotope studies have established that in the emerging callus, the maximum intensity of protein metabolism is established on the 15th day, and mineral - by 25 days. By the end of this period, the fragments are consolidated into a complete restoration of the supporting function of the damaged limb. Consequently, in the period from 10 to 25 days after the fracture and the operation of osteosynthesis, acute reactive phenomena fade and pronounced regeneration in the fracture zone prevails. This period is characterized by an increase in the content of total protein in the blood to the initial levels, a slight increase in the amount of albumin, normalization of alpha and beta globulins, a high level of gamma globulins and a significant decrease in mineral elements in the blood. The content of the latter is somewhat higher than the initial values, there is a slight decrease in their level at the ends of the fragments while increasing it in the callus. This period is characterized by a maximum increase in the enzymatic activity of alkaline phosphatase, protein and mineral metabolism in the bone-forming elements of the damaged bone and the emerging callus.

It should be noted that the maximum level of protein metabolism in the emerging callus precedes a period of high intensity and phosphorus-calcium metabolism. Such a ratio in protein-mineral metabolism in the process of bone tissue regeneration corresponds to the existing biological ideas that the protein matrix is ​​formed first, and then the crystallization of minerals occurs.

In the period from 25 to 60 days after the fracture and intramedullary osteosynthesis, albumin, gamma-globulin fractions and the A / G ratio (albumin-globulin ratio) are normalized, the content of mineral components in the blood decreases and the intensity of protein and some phosphorus calcium metabolism in bones and callus. After clinical recovery (8-12 months), the activity of bone phosphatase and phosphorus-calcium metabolism in the area of ​​the former fracture is maintained for a long time slightly above the initial level.

Radiologically, in the period from the 25th to the 60th day, the consolidation of fragments is established. The density of the shadows of the callus approaches the cortical layer of the ends of the fragments of the tubular bone. On the background. of these changes, gamma globulin fractions are normalized, the amount of albumins and the A / G coefficient increase, the content of which reaches the initial values ​​on the 60th day. The indicators of phosphorus-calcium metabolism in the blood serum after a slight increase on the 35th day further decrease, but continue to remain above the initial data. The content of mineral elements at the ends of fragments after a slight increase! by the 35th day it decreases again on the 45th day and only by the 60th day it increases and remains slightly higher than their level in the cortical layer of the intact diaphysis.

In the periosteal callus adjacent to the ends of the fragments, and in the callus at the level of the fracture, the amount of calcium and phosphorus increases and continues to remain for a long time, as noted earlier, above the initial level. The intensity of protein metabolism, according to radioisotope studies using radioactive methionine S35, gradually decreases and after 60 days. from the moment of fracture and osteosynthesis operation becomes almost the same. However, the intensity of protein metabolism remains 2-3 times higher than at the ends of fragments.

Consequently, in the period from the 25th to the 60th day of healing of fractures of tubular bones, the electrophoretic picture of blood serum proteins is normalized, the A/G ratio and the content of inorganic phosphorus in damaged and intact bones are restored almost to the level of the initial values, with the exception of the emerging callus, in which still has a high content of mineral elements.

According to radioisotope studies, the level of protein and phosphorus-calcium metabolism decreases, but on the 60th day it remains higher than in the ends of the fragments and symmetrical areas of the diaphysis of the intact femur. At this time, a strong consolidation of fragments occurs and the supporting function of the damaged limb is fully restored.

It should be noted that the healing process in different animals has some of its own characteristics. So, in sheep and cattle, in comparison with dogs: in the area of ​​damage, fibrous proliferative inflammation prevails over exudative inflammation. They have an earlier fixation of fragments by paraossal fibrous callus and the consolidation of the fracture occurs much faster. Fractures of bones in sheep and calves grow together for 10 days. earlier than in dogs and horses.

In case of bone fractures in animals, various complications can be observed. The most dangerous of them are osteomyelitis in open and gunshot fractures, contractures and false joints (pseudoarthrosis). Osteomyelitis is described in the relevant section of this book.

Complications in fracture healing

Contractures are formed with improper union of fractures and are persistent and irreversible. Defective sick animals are culled.

false joint- persistent abnormal mobility at the site of the former fracture, resulting from a violation of the process of callus formation (incl., Fig. 25). A false joint should be distinguished from delayed healing of fractures of injured bones. If there is mobility at the fracture site even in a relatively long time after the fracture, but there are no characteristic symptoms of a false joint on the radiograph, then this phenomenon is considered as delayed fracture healing.

According to the pathoanatomical picture, they distinguish: fibrous false joints (the ends of the fragments are connected by fibrous tissue, which has a transverse direction of the fibers to the axis of the bone); dangling false joints (the ends of the fragments have a rather strong divergence and mobility over a wide range); fibrosynovial, or true false joints (there is a modeling of the ends of the fragments according to the shape of the joint, covering with cartilage and connecting them with a fibrous capsule containing serous-mucosal fluid).

Etiology. False joints arise as a result of a violation of the formation of connective tissue, and then callus. They can be in the presence of large bone defects at the fracture site and are formed as a result of untimely and incorrect reposition of bone fragments and immobilization. False joints occur when the process of bone tissue regeneration is disturbed and under conditions that slow down the stimulation and formation of callus. Prolonged inflammatory purulent processes in open fractures are also one of the causes of pseudoarthrosis.

Clinical signs. Characteristic symptoms are painless abnormal mobility, absence of an inflammatory reaction in the fracture zone, and atrophy of muscles not involved in movement. On the radiograph, there is no callus and the process of regeneration, there are discrepancies in bone fragments, roundness of their ends and closure of the medullary canal with a compact layer of bone substance (with false joints in the long term). The rounded ends of the fragments are covered with a thin layer of cartilaginous tissue, a kind of bag (capsule of the false joint) is formed around them.

Diagnosis established on the basis of clinical signs and x-ray data.

Forecast in the sense of restoring the function of a limb, it is unfavorable, but favorable for the life of the animal.

Treatment. False joints are eliminated by surgery. After appropriate surgical preparation, the area of ​​pseudoarthrosis is opened, the ends of the fragments are removed and connected with pins. After the operation, the animals are given rest and agents that stimulate osteogenesis are used.

Prevention. To prevent pseudoarthrosis, it is necessary to reposition and immobilize bone fragments in a timely and correct manner after a fracture. With significant defects in the fracture zone, the edges of the fragments should be brought as close as possible. If they are sharp, then they are cut down. Suppurative processes are also eliminated. In case of violation of bone regeneration processes, it is necessary to find out the etiological causes of the main and predisposing nature and take appropriate measures.
CONDITIONS THAT DELAY AND STIMULATE BONE CALL FORMATION

The biological process of fracture healing and the duration of callus formation depend on timely and high-quality surgical care, the nature and location of the fracture, the general condition of the animal, feeding and maintenance conditions, age and other reasons.

The reasons that slow down the formation of callus and healing of fractures can be general and local. The common ones include rickets, osteomalacia, beriberi, pregnancy, disorders of the thyroid and parathyroid glands, as well as infectious diseases.

Local causes include poor immobilization of fragments, divergence of their ends, penetration of soft tissues between them, significant destruction of the blood vessels of the periosteum and bone marrow, penetration of synovial fluid into the gap between the fragments (with intra-articular fractures), purulent osteitis and osteomyelitis.

Treatment for delayed callus formation after the elimination of the causes, it should be directed to the use of general and local agents that stimulate the development of osteoid tissue and its calcification. For these purposes, it is necessary to provide animals with complete feed, enrich diets with vitamins C, D, mineral supplements, bone sawdust, and also use functional therapy (passive movements, wiring, dosed light work). From pathogenetic therapy, novocaine blockades and tissue therapy, as well as ultraviolet irradiation, diathermy, calcium electrophoresis should be used.

Noteworthy for stimulation of bone tissue regeneration is the introduction into the bone marrow canal of an alcohol-novocaine solution (2% solution of novocaine in 30 ° wine alcohol) on the first day after injury and after 5-6 days. back to the fracture zone. Good results are given by travertines with feed at a dose of 0.2-0.5 g per 1 kg of animal weight for 30 days. This contributes to the normalization of mineral metabolism and accelerate the consolidation of the fracture by 5-10 days. The same results are obtained when using pyrogenal at a dose of 1.5 gamma (15 MPD - minimum pyrogenic doses) per 1 kg of animal weight for 20-30 days. with an injection interval of 48 hours.

A large number of experimental and clinical studies have been devoted to the issue of stimulation of bone tissue regeneration in fractures. Some of the methods of stimulation proposed at one time are not used in surgical clinics and are mainly of historical interest only.

Special literature provides data on the influence of various hormones on the recovery process, since it is known that as a result of injury, adaptive mechanisms are activated in the pituitary-adrenal cortex system with increased release of the corresponding hormones.

Of greatest interest is the recently discovered thyroid hormone thyrocalciotonin (D. H. Coppetal, 1962; F. P. Hirschetal, 1963), produced by parafollicular cells. It has been proven that this hormone inhibits the resorptive process in bone tissue during fractures, while simultaneously increasing the level of protein metabolism and osteoblast activity in the bone regenerate.

Parathyroid hormones, unlike other hormones, have a directed effect on the cellular elements of bone tissue. They affect the transformation of osteoblasts, enhance the synthesis of specific proteins, RNA and alkaline phosphatase.

It has been established that steroid hormones normalize metabolic processes in trauma, reduce necrobiosis, increase the synthesis of mucopolysaccharides, and increase callus mineralization.

Studies of other substances - acetylcholine, norepinephrine, histamine, vasopressin have established their positive effect on the regenerative process. This was manifested in an improvement in the vascularization of the regenerate, a decrease in chondroid tissue, and an increase in ossification.

In experiment and clinic, a number of researchers have widely tested the stimulating effect of travertines on the healing process of bone fractures in dogs, sheep and cattle. It was noted that travertine top dressing at the rate of 0.5 g per 1 kg of animal weight for 30 days. from the moment of injury, it increases the enzymatic activity of alkaline phosphatase in the bones and blood serum, the intensity of phosphorus-calcium metabolism in the bone-forming elements of the damaged bone and tissues of the emerging callus and accelerates by 10-15 days. fracture consolidation. Travertine normalizes mineral metabolism in the bones and significantly reduces the negative effect of the metal pin on the damaged bone, reducing the effects of reefation in it.

Some scientists tested alcohol-novocaine solutions of low concentrations (1-2% solution of novocaine in 30% wine alcohol) on different types of animals with bone fractures. Double injection of this solution into the bone marrow canal and soft tissues surrounding the fracture site (during the osteosynthesis operation or in the first days after the fracture and on the 5-6th day after the injury) causes prolonged pain relief and accelerates the healing process.

In a number of studies, researchers have noted that intramuscular injection of pyrogenal to animals with bone fractures during intramedullary osteosynthesis at a dose of 1.5 gamma (15 MPD) per 1 kg of animal weight for 30 days. with injection intervals of 48 hours, it contributes to an earlier normalization of total blood serum protein, an increase in the intensity of protein-mineral metabolism, alkaline phosphatase activity in the bones and an acceleration of 5-10 days. fracture healing (incl., Fig. 35).

The advances in physics associated with the discovery of isotopes have created new possibilities for the use of the latter for therapeutic purposes in medicine and veterinary medicine. A number of researchers come to the conclusion that if relatively large doses of radioactive substances inhibit the formation of callus, then small doses, on the contrary, actively stimulate it.

Introduced into the body orally and parenterally, P32 quickly disappears from the bloodstream (after 1.5-2 hours, only 2-3% of the administered amount remains). A particularly large accumulation of P32 is observed in the bone skeleton and at the fracture site, as well as in the liver, spleen, kidneys, intestines, muscles and less in the blood, skin and brain.

According to L. M. Kapitsa and A. D. Fedorova (1954), radioactive phosphorus, injected between bone fragments at a dose of 1.6 microcuries per 1 kg of animal weight, accelerates the healing of the fracture every other day, and large doses of this drug act depressingly on formation of bone marrow.

It has been established that a single injection of microdoses of phosphorus (32/0.01 mccurie per 1 kg of animal weight) into the fracture zone of the bones has a beneficial effect on the healing of fractures, accelerating, respectively, by 5-10 days. fragment consolidation. It was noted that the local application of a 2% lactic acid solution in order to stimulate bone formation during delayed maturation of the callus enhances regenerative processes mainly due to the activation of the cambial layer of the periosteum.

To stimulate the healing of fractures of tubular bones in rabbits, complex compounds of trace elements of cobalt (Co35 and Co50) and copper (Cu5) were used by electrophoresis. It consisted in the following: a gasket impregnated with a 0.3% solution of Co35 was applied to the fracture site and connected to the anode of the galvanic apparatus; current strength 2.5 mA, exposure 25 minutes, daily sessions, course of treatment 25-30 procedures.

To date, a lot of data has been accumulated, indicating that external electric fields affect the recovery processes in the bone after a fracture.

Ultrasound of low power (0.05-0.2 W/cm2) stimulates the processes of consolidation, and a strong one can lead to their slowdown up to a stop. Many researchers report a significant acceleration of the process of bone tissue regeneration under the influence of low doses of ultrasound (0.1-1 W/cm2), and at a dose of more than 4 W/cm2, they note a slowdown in the union of bone fractures.

The stimulating effect of ultrasound on the formation of callus is explained by the fact that micromassage of cells and tissues by ultrasound leads to the displacement of molecular atoms in them, causes a kind of shaking of the constituent parts of the cytoplasm, and contact between the substances of the cell, which is unusual for ordinary conditions, also occurs. This determines the increase in the intensity of enzymatic metabolic processes.

Regeneration of bone tissue after irradiation with a helium-neon laser with a wavelength of 6328 ° A ° and a different output power of 12 mW leads to earlier formation of callus in irradiated groups of animals (N. A. Shugarov, D. V. Voronkov, 1973; V. N. Koshelev et al., 1973; DV Voronkov, 1976), and with an increase in exposure from 1 to 10 minutes, the stimulating effect increases accordingly.

Noteworthy is the study by N. K. Ternova et al. (1977) in an experiment on the influence of the stimulating effect of interferon on reparative osteogenesis. Among the most active inducers of iterferon is a synthetic double-stranded polyribonucleotide of inosinic and cytidilic acids.

Interferon (I. Pofy, C. Pofy, 1963) was prepared in sterile saline with pH adjusted to 7.6 at a concentration of 1 mg/ml. The drug was used intravenously 24 hours before the operation at the rate of 0.2 mg per 1 kg of animal weight, then immediately after the operation and subsequently 5 days later during the first month.

The authors note that the stimulating effect of interferon can be traced at all stages of bone tissue regeneration. Apparently, the stimulation is based on the acceleration of the differentiation of cellular elements, and not on the elementary mobilization of the proliferative properties of cellular elements. A more active course of osteogenesis is manifested by the early formation of bone beams.

The main phenomenon is a noticeable activation of the processes of restructuring of the bone tissue regenerate up to an earlier maturation of the newly formed bone tissue and its organ restructuring. The interferon inductor affects the rate of differentiation of cellular elements and activates the proliferation of fibroblasts - connective tissue cells.

Pyrimidine derivatives (methyluracil and pentoxyl) have been extensively tested under experimental conditions and tested in clinical practice in various human and animal pathologies due to their pronounced anabolic effect on the body due to active interference in the synthesis of nucleic acids and protein.

V. I. Rusakov and I. F. Grekh (1954, 1969, 1970, 1972) proved the anti-inflammatory effect of pyrimidines. V. G. Garibyan et al. (1959) studied the effect of metacil on the course of experimental fractures and noted that in the control group, the bone defect was replaced on average in 78 days, while in animals after the administration of metacil, in 61 days and cytosine, in 55 days.

MA Korendyasov (1961) conducted a clinical and experimental study of the effect of certain pyrimidines (methyluracil, pantoxyl and citrosine) on bone tissue regeneration. 256 experiments were carried out on rabbits aged from 2 months to 3 years. All animals underwent the same type of operation: 0.6 cm of the radius was resected on the front paw, and pyrimidines were injected into the defect area along with antibiotics.

It was established that the topical application of pentoxyl had no effect on bone restoration, while methyluracil and citrosine accelerated the healing of a bone defect. Histological studies have shown that pyrimidines have an effect in the early stages of osteogenesis. In the experimental series, a pronounced periosteal reaction, massive growth of bone beams, and early appearance of osteoid tissue were observed. By the end of 3-4 weeks, bone consolidation occurred, and in the control series for 7-10 days. later.

Orotic acid, which was discovered in 1905 by Biscaro and Belloni, who isolated it from cow's milk whey, is used as a stimulant for the regeneration of bone fracture healing. Later, it was found in biological objects of animal and plant origin: liver, milk, yeast, mold, fungi, bacteria, blood, urine, etc.

Orotic acid is a derivative of pyrimidine bases. In the free state, it is white crystals with a melting point of 345-346°C (with decomposition). It is insoluble in acids, but readily soluble in alkalis and hot water (solubility in water at 18°C ​​is 0.2%) and has pronounced acidic properties, clearly forming salts with metals.

Unlike synthetic analogs of uracil (methyluracil and pentoxyl), orotic acid is a normal intermediate in the biosynthesis of pyrimidine nucleotides and is actively involved in the synthesis of nucleic acids. In addition, it is involved in the construction of other biopolymers: glycogen, complex lipids, mucopolysaccharides. An essential feature of orotic acid, which distinguishes it from other natural pyrimidines (thymine, uracil, cyrosine), is the ability to be included in macromolecular metabolism not in an activated form, but in a free form due to the existence of a specific pyrophosphorylase enzyme that converts orotic acid into orotidine-5-phosphate.

According to M. M. Pates et al. (1937), orotic acid and its derivatives stimulate erythro- and leukopoiesis. It is effective in violation of hematopoiesis caused by radiation exposure, has a preventive and therapeutic effect in liver damage caused by various hypotoxemic substances.

Fundamentally new is the use of potassium orotate for the treatment of liver disorders in diabetes mellitus (AV Lesnichiy, 1970). A distinct anti-inflammatory effect and an increase in the immunological activity of the body with the introduction of potassium orotate have been established by many scientists. At a dose of 100 mg / kg, the drug increases the activity of leukocytes and the formation of antibodies in rabbits with an altered reactivity of the body.

Consequently, the versatile effect of pyrimidines on the regeneration of various tissues and organs is associated with their active intervention in metabolic processes and, above all, stimulation of protein synthesis. The anabolic effect of pyrimidines has been confirmed by a number of researchers.

The activity of orotic acid is manifested primarily in its distinct anabolic and anti-catabolic action. Numerous researchers have noted the pronounced ability of orotic acid to accelerate the reproduction of bacteria and stimulate tissue growth.

When studying some aspects of the mechanism of action of orotic acid, V. I. Porallo et al. (1975), G. I. Bilich et al. (1975) came to the conclusion that it increases the content of nucleic acids and active acid nucleases in regenerating lung tissues in the early stages after surgery, while the use of potassium orotate after gastrotomy, along with an increase in the amount of nucleic acids, leads to a decrease in acidic DNA activity.

KG Berkhout (1969) successfully used potassium orotate in the postoperative treatment of traumatic nerve injuries. BM Novikov (1976) studied the effect of orotic acid on the regeneration of injuries to the anterior abdominal wall and stomach. The author notes that orotic acid is an effective stimulator of reparative regeneration of soft tissues and the stomach due to direct active intervention in the synthesis of nucleic acids, and, consequently, in the entire protein synthesis. However, as shown by histological studies, it exhibits a local anti-inflammatory and anti-edematous effect.

The diverse effect of pyrimidines on the body is essentially reduced to one phenomenon - the stimulation of protein synthesis, which causes the acceleration of the regeneration of various tissues (connective, bone, muscle tissue, epithelium, antibody production, etc.) against the background of a more or less intensive course of reparative processes.

The effect of orotic acid on osteogenesis in bone trauma was studied (M. V. Plakhotin, L. Ya. Loktionova, V. A. Lukyanovsky, Yu. I. Filippov and N. I. Ochirov, 1976-1980). It was applied to the surface of the polymer pin under the polymer film at a dose of 30-50 mg. By X-ray and histological studies, the authors found that a polymer pin implanted in the medullary canal of the epiphyses with subsequent closure of the bone defect with an autoreplant does not cause any pathological changes in the bone tissue. Orotic acid applied to the pin at a dose of 35-50 mg stimulates osteogenesis and accelerates the engraftment of the autoreplant 2 times faster than in control animals (incl., Fig. 32, 33).

It has also been established that orotic acid has a positive effect on the regenerative processes and the development of callus during intramedullary metal osteosynthesis (incl., Fig. 31). The metal pin used for osteosynthesis in combination with orotic acid is removed from the medullary canal 5-7 days earlier than usual. In addition to positive properties, acid prevents the early development of aseptic osteomyelitis.

Thus, to stimulate the healing of bone fractures, there are a large number of agents, the timely use of which gives positive results in the treatment of animals.

Prevention of bone fractures. The prevention of most bone fractures is based on measures aimed at eliminating closed and open mechanical damage, acute purulent inflammatory processes localized near the bones. Creation of appropriate conditions of detention, sufficient intake of vitamin and mineral components into the animal's body, physiologically normal metabolism also make it possible to prevent bone fractures. It should be borne in mind that even minor injuries, bruises, mechanical violence in some cases with a weak resistance of the body and belated surgical care can lead to serious complications. Therefore, first aid to a sick animal must be provided as early as possible and qualified.