Surgical treatment of anterior cruciate ligament rupture in dogs. How to treat torn and sprained ligaments in dogs

Rupture of the anterior cruciate ligament (ACL) is one of the most common pathologies in dogs knee joint, which inevitably leads to the development of osteoarthritis and lameness in the hind limb.
The primary function of the ACL is to provide stability to the knee joint. This ligament has important biomechanical functions: it prevents excessive rotation and displacement of the tibia forward, and also protects the joint from overextension.

A bit of anatomy.

The knee joint is the most complex both anatomically and functionally. In its formation in dogs involved: lower section , upper divisions tibia and fibula, patella and three sesamoid bones. The knee joint unites three interconnected joints: femoral, femoral and tibiofibular.

Basically, the knee joint is supported by the internal and external lateral ligaments, as well as the anterior and posterior intra-articular cruciate ligaments. The cruciate ligaments are located between the femur and tibia, and together they prevent abnormal mobility in the joint. When walking, the anterior ligament prevents the lower leg from moving too far forward, while the posterior ligament limits the movement of the lower leg backward.
On the surface of the epiphysis of the tibia (in the cavity of the knee joint) there are two cartilaginous discs - the outer and inner menisci. They protect the articular surfaces from excessive mechanical impact, as well as provide a more complete articulation bone structures. When the ACL is torn, as a result of pathological mobility in the joint, the posterior part of the internal meniscus is often wedged, which leads to its rupture.

Predisposing factors to the rupture of the ACL can be:

excess weight and features of the constitution of the dog;
excess physical activity after prolonged physical inactivity;
deformations in the structure of the knee joint;
dislocation patella or its abnormal location;
violations in the anatomy of the hind limb;
hereditary factor.

Dogs with anterior cruciate ligament disease can be divided into 4 groups based on causes of disease:

1. Rupture due to ligament degeneration in older dogs.

Most common in animals aged 5-7 years. The disease occurs in all dogs, including small breeds(poodle, Yorkshire Terrier, Lhasa Apso, Bichon Frize, Cocker Spaniel).
At large breeds in the beginning, only a partial rupture of the ligament often occurs. In this case, lameness appears, which then suddenly increases, as a partial rupture leads to a complete rupture of the ligament. This can happen after a minor injury or during normal physical activity.

In small breeds, it is almost always not a tear of the ligament, but a complete rupture of it, which facilitates diagnosis.

With degenerative changes, the ligament becomes less strong, and its rupture occurs much more easily. The main reasons for such processes include age, developmental anomalies (dysplasia) and dislocation of the patella, as well as a sharp increase in physical activity.

2. Ligament rupture in young dogs.

It is more common in large and giant breed dogs between the ages of 6 months and 3 years, especially in the Rottweiler, Mastiff, St. Bernard, Newfoundland, Labrador and Boxer. A cruciate ligament injury is usually characterized by partial rupture and chronic pathological changes in the joint associated with osteoarthritis. Such "early" degeneration of the ligament can be caused by structural features of the knee joint and the pelvic limb as a whole.

3. Ligament rupture due to inflammation of the knee joint.

Pathological changes in the PCC can occur with infectious inflammation knee joint, for example, the course of purulent arthritis can cause melting of the anterior cruciate ligament with the occurrence of its rupture.

4. Rupture due to trauma.

This type of damage is extremely rare. Injury is possible with overstretching of the ligament at the time of joint extension and simultaneous excessive internal rotation of the lower leg. Damage can occur when running in hilly terrain and deep snow. In this case, lameness appears suddenly, immediately after exercise.

Clinical signs of torn anterior cruciate ligament.

The manifestation of symptoms of the disease depends on:

degree of rupture: complete or partial rupture of the ACL;
type of rupture: one-stage or staged;
the presence of damage to the menisci of the knee joint;
the severity of the inflammatory process in the joint.

With a partial tear of the anterior cruciate ligament, stability in the knee joint is usually preserved. There is pain and intermittent claudication. There may be concomitant damage to the menisci of the knee joint, and in the future, if left untreated, there is a risk of complete rupture of the ACL. In this case, lameness progresses rapidly.

A complete rupture of the ACL is characterized by the sudden onset of lameness. The dog holds its paw in the air with a slightly bent knee joint. Painful swelling is observed in the area of the knee joint. After 7-10 days, the dog begins to use the limb when walking, but when standing, only slightly touches the ground with his fingers. When walking, a "click or crackle" sound may be heard due to the femoral condyles sliding back and forth from their normal position on the menisci. These phenomena indicate functional instability of the knee joint.

Due to the violation of the support ability, atrophy of the muscles of the hind limb gradually develops.

After 6-8 weeks, restoration of stability in the knee joint is possible, especially in small breeds, it occurs due to the thickening and scarring of the joint capsule. Do more large dogs weighing from 10-15 kg, as a rule, remains varying degrees lameness, due to pathological changes associated with damage to the meniscus and the development of osteoarthritis.

Quite often, if present internal causes diseases, in dogs with unilateral ACL rupture, a ligament rupture occurs on the opposite side within a year and a half.

Diagnostics Anterior cruciate ligament rupture is based on history, clinical examination, and radiography of the knee joint area.
Complete information about how the injury occurred is important in making a diagnosis. During the examination, the doctor examines the knee joint for an anterior drawer symptom. In this case, there is pathological mobility in the joint with the displacement of the head of the tibia forward in relation to the femur. To improve the quality of the study, especially in large dogs, it may be necessary to general anesthesia. With a partial tear of the ACL, there may not be a “drawer” symptom. For such cases, a slight, almost imperceptible pathological mobility is characteristic.

To date, the most accurate method for diagnosing damage to the ligamentous apparatus and menisci of the knee joint is magnetic resonance imaging (MRI).
In certain cases, arthroscopy may be used. This surgical procedure consists in introducing a special device with a microvideo camera into the joint cavity. It is indispensable for suspected ACL tear and meniscus injury.

Differential diagnosis.

A number of pathologies of the knee joint are clinically similar to ACL rupture. As a rule, all of them are accompanied by lameness and pain, but there are differences.

Rupture of the posterior cruciate ligament (rare) is accompanied by a displacement of the lower leg relative to the thigh backwards, the so-called "posterior drawer" syndrome. Dislocation of the patella is well diagnosed by palpation, it is also necessary to exclude other traumatic injuries knee joint. If a tumor process in the knee joint is suspected, x-ray and histological examinations will be required.

Treatment.

The main criteria in choosing a method of treatment for cruciate ligament rupture are the following factors:

the age of the dog;
weight and features of the constitution;
activity level;
the degree of pathological joint mobility;
age of damage.

For dogs of small breeds weighing up to 10-15 kg, with a rupture of the anterior cruciate ligament, conservative treatment by limiting the load with short walks on a leash for 6-8 weeks. The body weight of the animal should be monitored in order to reduce the load on the knee joint. Approximately in 85% of cases, satisfactory function of the limb is restored. In small breeds, lameness can go away forever. If the lameness persists, the dog undergoes surgery.

In dogs weighing more than 15-20 kg, lameness can also temporarily disappear, but after a while it resumes due to the development of arthrosis of the knee joint, which will be incurable. Thus, in large breed dogs, early stabilization of the knee joint is required to reduce the likelihood of developing osteoarthritis.

In order to speed up recovery and improve joint function, surgery can be recommended for almost all animals.

Surgical treatment is to conduct a revision of the knee joint. This will require arthrotomy (opening the joint cavity) or arthroscopy, which will remove the ACL fragments, examine the menisci and, if necessary, remove the damaged part of the meniscus. To create additional stabilization of the joint, the joint capsule is sutured "overlapped". In animals weighing less than 25 kg, this method may be sufficient to stabilize the joint even without the use of additional methods fixation. Within 2-3 months, due to fibrosis (thickening) of the capsule, stabilization of the knee joint occurs. Depending on the type of surgery, duplication of the capsule can be performed before or after additional stabilization of the joint.

The methods by which additional stabilization of the knee joint is carried out can be divided into two main groups: intra-articular and extra-articular.

At the core extra-articular method lies the use of an implant. It is placed near the start and end of the ACL so that it overlaps the joint and thereby restores joint stability. This operation is more often used in dogs of small and medium breeds with a rupture of the anterior cruciate ligament. Another extracapsular method is a triple tibial osteotomy. To date, this is the most effective operation for dogs of large and giant breeds with angular deformity of the tibial plateau. After such an operation, it is not necessary to wear a fixing bandage.

At intracapsular In operations, the damaged ligament is replaced with a synthetic prosthesis or autograft (own tissue).

In the postoperative period, antibiotic therapy is used. To reduce the load on the operated limb in the postoperative period, movements in the knee joint are limited (using a Robert-Johnson bandage).

For symptomatic treatment, your doctor may prescribe analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), or hormonal preparations. So, for example, with a complete rupture of the ACL, the use of the above drugs will cause a decrease in pain, the dog will begin to use the limb more actively, increasing the load on the unstable joint, which, as a result, will lead to an increase in destructive phenomena in it. Chondroprotectors and glucosaminoglycans can only be used to stop degenerative changes in the articular cartilage.

Forecast with rupture of the anterior cruciate ligament, in general, depends on the timely manner. Prolonged instability in the knee joint leads to the development of arthrosis and lameness, especially in large animals.

Ligaments are called fibrous strands that connect the adjacent parts of the joints. Their structure is elastic and therefore sprains in dogs or ruptures are the most common injury.

A sprain is a tear in the fibers of a ligament. Its severity is determined by how many fibers are damaged. If not many fibers are torn, the sprain is considered insignificant, because the function of the joint is not impaired, there is practically no swelling and bleeding.

In fact, only pain is observed. In a severe sprain, extensive tearing of the fibers is accompanied by swelling, bleeding, limited range of motion in the joint, and severe pain.

Types of Ligament Tears in Dogs: Symptoms, Diagnosis, Causes

For the life of a dog, ruptures of the ligaments of the spine are the most important. They occur with a serious injury with fractures and dislocations of the vertebrae and can lead to impaired urination, paralysis, paresis.

Diagnosis of this injury can be based on X-ray, neurological examination, etc., and treatment can be mainly in the form of surgery. In some breeds of dogs (Chihuahua, Toy Terrier, Yorkie), spontaneous rupture of the ligaments leads to abnormal development of the first and second cervical vertebrae. In this case, the dog wears a corset and is prescribed corticosteroids.

Surgical intervention is indicated only in the absence of the effect of conservative treatment. In dogs, the most common knee disease is an anterior cruciate ligament (ACL) tear, which leads to osteoarthritis.

This ligament can be torn as a result of trauma or regular trauma, degenerative changes, inflammatory diseases of the joint. The disease is manifested by the fact that. More often the dog keeps its paw on weight, slightly bending the knee joint.

Small animals (up to 15 kg) are treated without surgery, while medium and large animals are recommended to be operated on immediately. Tears and sprains of other ligaments (carpal, shoulder, elbow, hip, hock, etc.) are most often associated with joint dislocations. In case of rupture of these ligaments, the joint is simply fixed for 3-4 weeks.

First aid and treatment for sprains and ruptures of ligaments

If the dog suddenly limps, especially after jumping or falling, put something cold on the damaged area for 20 minutes, and then apply a tight bandage or elastic bandage. With such injuries, it cannot be used, because, without feeling pain, the animal will start to run, and this will further injure the damaged joint.

The caudal and cranial cruciate ligaments are two criss-cross structures that lie between the femur and tibia. They work together to help prevent abnormal movement of the tibia relative to the femur. When the animal moves, the cranial ligament keeps the tibia from moving too far forward, and the caudal ligament prevents the tibia from moving too far back. A cruciate ligament tear results in a total or partial loss of the knee joint's ability to function and move normally. With the loss of the cranial ligament, the knee becomes extremely unstable, which places enormous pressure on the weaker stabilizing mechanisms around the joint, and this, in turn, gradually leads to deterioration of the joint.

The link between anterior cruciate ligament rupture in dogs and genetics has not yet been proven. There is a need to study this issue in more detail in order to reduce the risk of such anomalies. This potential incapacitating damage affects both service dogs, and pets, but it is especially common in Labradors and Rottweilers under the age of 4 years. Other breeds of dogs older than 5 years and large breed dogs aged one to two years can also be included in the risk group. More often subject to this disease female dogs.

Symptoms

The severity of the disease and the condition of the animal depends on the degree of damage to the ligament, which can be either complete or partial. Also, for the correct diagnosis and the appointment of adequate treatment, information is needed on how the damage occurred, whether it happened at the same time, or whether the condition worsened over time. Externally, the gap is expressed in the fact that the knee joint loses its mobility, external changes are usually also noticeable. The most common mechanism of rupture is overstretching of the ligaments and excessive internal rotation of the lower leg in the position easy bending. Sudden rupture of the anterior cruciate ligament leads to lameness and fluid accumulation in the joint, bleeding. The injured leg will always be in a bent position if the dog is standing. In the case when the ligament is damaged gradually, lameness may not be immediately noticeable and even disappear for a while. Similar state can last from several weeks to several months, causing suffering and pain to the animal. However, it can function normally. Often, due to the fact that the muscles of the affected leg are not involved in full-fledged movement, muscle atrophy develops, that is, a decrease in their muscle mass and weakening. Most often this applies to the quadriceps femoris. Ligament damage, if left untreated, leads to complete atrophy of the knee joint, leg muscles, the condition of the articular cartilage will worsen, and inflammation may also worsen.

The reasons

The most common cause of anterior cruciate ligament injury in dogs is repetitive microtrauma that gradually leads to complete or partial rupture of the anterior cruciate ligament. Such impacts gradually stretch the ligament tissue, change its structure, which ultimately leads to rupture. Such changes are also called degenerative. There are many reasons that cause degenerative changes, among them are age, developmental anomalies, a decrease in the load on the ligaments associated with the restriction of dog walking, as well as factors associated with a weakened immune system. Anomalies of development can be shown in the course of growth of an animal. If the bones are not formed correctly, the load on the ligaments will be excessive, which can lead to damage. Often the cause of degenerative changes is the overweight of the animal. Also, if an overweight animal suffers a ligament injury once, it increases the likelihood that the next time the injury will occur in the same place, which is not conducive quick recovery. A common cause of anterior cruciate ligament tear in dogs is various injuries knee joint. It is especially dangerous to get injured if the knee ligament has already been weakened before. A dislocation of the patella or a severe bruise (for example, in the event of a car accident) also leads to a rupture.

Diagnostics

In order to determine the rupture of the cranial cruciate ligament, the veterinarian may apply several various ways. Usually use the symptom of the "drawer" in the position of flexion, extension and standing. A similar symptom is easily determined in acute ruptures. However, almost imperceptible mobility, gradually disappearing, is also characteristic of sprains, it appears as a result of a partial rupture of the ligament. If the cranial ligament moves upward towards the femur, this indicates a rupture. This method can also give false positive results so there are other methods.

X-ray examination cannot be one hundred percent to determine the rupture of the ligament, but it greatly helps in the detection of pathological intra-articular processes, for example, fluid in the joint cavity and periarticular osteophytes, compression of the patellar fat pad, avulsion or calcification of the cranial cruciate ligament.

The veterinarian may also order an MRI as an additional examination to help locate the outline of the affected cruciate ligaments and menisci. With the help of a puncture taken from the fluid contained in the knee joint, a veterinarian can diagnose an intra-articular lesion and rule out sepsis, as well as immune-mediated diseases.

Arthroscopy can also directly view the cruciate ligaments, menisci, and other intra-articular structures.

Treatment

For small dogs weighing less than fifteen kilograms, conservative outpatient treatment is usually prescribed. In more than half of the cases, the restoration of the functioning of the joint is guaranteed. During this period of time, the animal is taken outside only when necessary and must be on a leash.

For dogs weighing more than fifteen kilograms, the prognosis for outpatient treatment not so positive, only in 20% of cases a complete cure is possible. Often, surgery is required, which increases the chances of a cure.

For some time you will have to limit the physical activity of the animal. The duration of the restriction depends on the method of treatment and the dynamics of recovery. AT postoperative period physical exercises that help develop the joint are of great importance. To reduce the load on the damaged joint, it is extremely important to monitor the weight of the animal.

To restore the mobility and stability of the knee joint, alternative methods are also used, such as implantation and others. Usually, veterinarians, in addition to the main treatment, also prescribe sedatives and painkillers.

Further observation

Once your pet has been diagnosed and treated appropriately, it is important to follow all of the veterinarian's instructions exactly. After the operation, it will take time to recover, sometimes it takes up to six months. If an animal has a genetic predisposition to degenerative damage to the knee joint and ligaments, it makes sense to spay it so as not to pass on this tendency to descendants. In about 10% of cases, a second operation may be required, since in more than 50% of dogs, a cranial ligament tear is accompanied by a medial meniscus tear. It is a crescent-shaped cartilage located between the femur and tibia. In the case of surgery, the chances of a complete cure are much greater than with conservative treatment.

A common injury, especially among young and active dogs, is sprains of muscles, ligaments, and tendons. Classes on the training ground and playing with relatives make the pet show "miracles of plasticity", which often leads to joint injuries. A sprain in a dog occurs if the pet overestimated its strength and "overloaded" the joint, which was in the most "open" form.

Note! Muscle strain is not accompanied constant pain. The paws hurt when the dog tries to get up after sleep, "dispersing", the animal behaves normally.

The joint is a part of the skeleton that is responsible for flexion - extension of the limbs and shock absorption. elastic fibrous tissue The ligament consists of many thin fibers and nerve endings that protect the bones from the "shock wave", for example, when jumping. According to their functional purpose, ligaments are divided into:

Fixing- fastening of internal organs in the body cavity.

Guides- set the possible degree and direction of movement of the joint.

Strengthening and inhibitory- fix the joint, limit the maximum amplitude of flexion and extension, absorb shocks.

Note! Each step of the dog is a body hit on the ground, accompanied by vibration. Under depreciation, it is understood that the joint and ligaments take on most of the load on themselves, protecting internal organs and muscles from vibration.

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Considering the sprain of the limbs, the injury is divided into 3 degrees of severity:

Lung- joint overstrain, which is accompanied by pain, but does not imply a serious injury, maximum - microrupture of a few fibers connective tissue.

Average- the integrity of the ligament is not broken, but numerous fiber ruptures are observed.

heavy- complete rupture of the ligament. It stands out as a separate type of injury and requires specific treatment.

Note! If the limb is severely swollen, the dog has an acute pain syndrome, most likely, this is not a sprain.

Types, causes and signs of sprains in dogs

Normally, ligaments and joints must withstand the weight of the dog, jumps, falls, rolls and other active loads. In young puppies, during active growth, the connective tissues do not have time to get stronger and adapt to the weight of the dog. The phenomenon is observed in large puppies with massive joints - Caucasian and Central Asian Shepherd Dogs, St. Bernards, Great Danes are also in a special risk group. german shepherds and hunting breeds. In addition to an abnormally fast growth rate, possible reasons The "weaknesses" of the ligaments include:

Lack of calcium and other trace elements responsible for the regeneration of connective tissues.

Complex trauma -,.

Congenital disorders of the development of the skeleton. For example, at decorative dogs ligaments are injured due to improper formation of the vertebrae cervical. Sprain of the spine is perhaps the most dangerous case, requiring a long rehabilitation, wearing a corset and medication.

The most vulnerable places for sprains are the paws, more precisely, the joints that take part in shock absorption.

Sprain on the hind leg, most often suffers from jumping or hip joint. The dog presses the injured paw or stands only on the toe.

Cruciate ligament injury (knee)- consists of two crossed flaps of connective tissue. The dog does not lean on the paw, a slight sprain cannot be detected without x-ray.

Ankle sprain, sometimes described as an elbow injury back paw. The main sign is the incorrect arrangement of the joints of the paws - the hind legs are shifted inward (X-shaped), the front ones, on the contrary, are set apart.

Metatarsal joint (wrist) sprain– “favorite” injury of “jumping” dogs. However, it is not necessary for a quadruped to jump, the pet stumbled, twisted its paw, turned sharply while running and began to limp - this is a sprain.

A. N. EFIMOV,
cand. vet. Sciences, Associate Professor, Ch. doctor of clinic 000 "Lev"
St. Petersburg

In dogs susceptible surgical operation According to studies over the past three years, about 3% had a rupture of the anterior cruciate ligament of the knee joint. Among diseases of the musculoskeletal system, this pathology accounts for 6.1% and is inferior in terms of the number of fractures and dislocations.

Several methods have been described in the literature surgical treatment rupture of the anterior cruciate ligament of the knee joint, where the authors often point out their insufficient effectiveness. Applying the cruciate ligament prosthesis with lavsan for several years, we were convinced of the low efficiency and potential danger this method, which was a prerequisite for the development of a new method of surgical treatment.

PURPOSE OF THE STUDY

The purpose of this work is to find a way to functionally stabilize the knee joint after a rupture of the anterior cruciate ligament.

MATERIALS AND METHODS

Anatomical study of the knee joint, reproduction of the rupture of the anterior cruciate ligament, study of the consequences of its loss and development of a method for restoring the functional activity of the knee joint by stabilizing it (using the anatomical elements of the limb itself) were carried out on the corpses of 6 medium-sized dogs.

The implementation of the method developed by us was carried out in a clinic on 85 dogs different breeds with a torn anterior cruciate ligament of the knee joint.

Long-term results were monitored for 3 years.

Data on the condition of patients after the operation was obtained by questioning the owners both during the re-admission of animals for clinical examination and by telephone at the scheduled time.

Material about this pathology (anamnesis, breed, age, etc.) and the results of surgical treatment was obtained from the case histories.

RESEARCH AND METHOD OF CARRYING OUT SURGICAL OPERATION

During the reproduction of movements on the dissected limbs with a crossed anterior cruciate ligament, a wide amplitude mutual displacement of the articular surfaces in the area of the knee joint was established. It has been established that when the joint is extended, the femur, mainly when pressure is exerted on it from the side of the patella, is displaced plantarly (Fig. 3), while the tibia, moving forward from under the femur due to tension of the direct ligament, dorsally (Fig. Per). In this case, quite often the medial condyle of the femur overcomes the caudal horn (edge) of the medial meniscus. During flexion of the knee joint, the bones return to their original (normal) anatomical position. Thus, it has been established that the pathological displacement of the bones occurs under the influence of a powerful extensor of the knee joint - the quadriceps femoris, and their return to their original position is carried out due to the posterior group of such multi-articular muscles as the semitendinosus, semimembranosus, sartorius and biceps (its tibial part), as well as popliteal (Fig. 4).

Figure 1. Ligaments of the knee joint.

The described anatomical and physiological conditions made it possible to develop a method for dynamic stabilization of the knee joint, the main principle of which is to enhance the function of flexion by repositioning (displacing) the attachment sites of the legs (tendons) of the biceps and tailor muscles. We called the proposed method of extra-articular plasty biceps-sartoriotransposition.

Operation technique

Incision skin is carried out from the upper third of the thigh to the upper third of the lower leg along the dorsal surface of the limb, focusing on the lateral edge of the patella and its direct ligament. Thus, we expose the broad fascia and the tendon part of the biceps femoris and the fascia of the leg. Loose connective tissue (subcutaneous tissue) is dissected in the lateral and medial (to the point of attachment of the tailor's muscle) directions in relation to the incision line. Then we dissect the fascia lata along the dorsal edge of the biceps femoris, simultaneously cutting off the tendon (peduncle) of the latter from the patella and direct ligament. Then we continue the incision in the distal direction to the fascia of the leg 1 cm laterally from the crest of the tibia. After that, the biceps femoris muscle is separated from the fascia in the transverse direction at the level of the articular fissure line. Separating the leg of the biceps femoris muscle from the capsule of the knee joint in the latero-plantar direction up to the middle caudal artery of the thigh, we take the latter to the side. Using an arcuate incision from the crest of the tibia, following along the direct ligament, patella and the lateral edge of the rectus head of the quadriceps femoris, we open the knee joint. The kneecap, together with the direct ligament and the quadriceps femoris muscle, is shifted to the side medial surface, thereby widely opening the cavity of the knee joint. After a thorough examination, we remove fragments of the anterior cruciate ligament and, if necessary, the anterior horn of the medial meniscus and bone formations(exostoses) along the edges of the articular surfaces. We wash the joint cavity with physiological saline, reposition (restore to its original position) the patella, and suture the incision of the capsule with a two-row suture. Then we mobilize the legs of the tailor's muscle. We dissect its caudal part from the loose connective tissue and separate it from the tibia. After that, we carry out reimplantation of the biceps and tailor

Figure 2. Mechanism of action of the anterior cruciate ligament.

muscles in a new place. We fix the distal end of the pedicle of the biceps femoris muscle with loop-like sutures to the fascia flap of the lower leg on the crest of the tibia (Fig. 5). Here we hem the leg of the tailor's muscle. After extension of the knee joint, we suture the incision of the wide fascia of the thigh (due to the strong tension of the tissues, the suture material must be strong). The completion of the surgical operation is carried out by layer-by-layer stitching of tissues (superficial fascia, subcutaneous tissue, and skin). In all cases, except for the skin, we use nonreactive absorbable suture material.

In the postoperative period, we do not immobilize the operated limb. During the first week after the operation, we prescribe antibiotics and carry out symptomatic treatment. The stitches are removed after 7-10 days. To prevent detachment of the reimplanted muscles, we restrict the movement of the animal for 3 weeks. In general, the operation is well tolerated by the patient. Improvement general condition and swelling of the operated limb are completed by the end of the first week (during this time, the animal begins to gradually lean). With a positive dynamics of recovery, lameness disappears after 3-6 weeks without the use of additional therapy.

REMOTE INVESTIGATION

A retrospective analysis of the results of treatment of anterior cruciate ligament rupture in 86 dogs with the surgical method described above was evaluated as follows (Table 1):

Figure 3. The mechanism of the occurrence of pathological mobility when the limb is supported.

An excellent result is a complete restoration of the function of the operated limb without any restrictions;

A good result - the dog moves freely, but with heavy loads there is a slight transient lameness without treatment;

Satisfactory result - periodically occurring mild lameness, which requires a short prescription of non-steroidal anti-inflammatory drugs;

Table 1. Evaluation of the results of surgical treatment of anterior cruciate ligament rupture in 85 dogs using extra-articular plasty of the legs of the femoral and sartorius muscles.

*Grade* *results* *operations*	*Quantity*	*Interest* *(%)*
A great	66	77,6
Good	15	17,6
Satisfactory	3	*3,5*
Unsatisfactory	1	L3
Total:	85	*100*

Unsatisfactory result - permanent lameness.

When analyzing the case histories of dogs subjected to extra-articular plasty, it was found that this pathology spread among various breeds (Table 2).

It has been noted that the lameness that occurs in animals due to rupture of the anterior cruciate ligament was found during a normal walk. From the survey of owners it follows that the dog "stumbled", "twisted his leg", etc. Sometimes the animal began to limp the next day, and its owner recalls that the day before, during a walk, it squealed. Quite often, after this episode, the dog's short-lived lameness was reported to resolve spontaneously, or the treatment was short-lived, but after exercise it reappeared and became more pronounced.

Therefore, if the dog begins to limp “out of the blue” and the owner cannot assume that serious damage lies behind this, such a late arrival of the animal for a consultation with a veterinarian is explained. According to our study, in most animals, the time of manifestation of the above symptoms ranged from two weeks to several months. Unfortunately, as it was established from the anamnesis, one of the reasons for the late admission of patients to the clinic with this pathology was the unsuccessful conservative therapy due to an incorrect diagnosis.

The diagnosis of an anterior cruciate ligament rupture of the knee joint is usually not difficult, since its formulation is based on data from the anamnesis, the presence of lameness, usually of the second degree, and inflammation of the knee joint. The final diagnosis is made when an anterior drawer symptom is found in the knee joint. It consists in free movement forward proximal lower leg in relation to the distal part of the thigh, which is easier to establish in an animal in a state of relaxation. On radiographic examination characteristic features, indicating this pathology, are usually not detected, but its conduction is necessary, since this allows to exclude other damage at the level bone tissue knee joint.

It has also been found that the use of anti-inflammatory therapy usually leads to a temporary improvement, after which the pathology worsens, and lameness becomes more pronounced. Often, upon repeated treatment, this group of patients showed signs of meniscus damage (clicks in the joint during walking and forced movements of the limb).

DISCUSSION

The knee joint is a complex, uniaxial anatomical structure. The articular surfaces of the condyles of the femur and tibia (form the femoral joint) have a convex shape and giving them congruence is provided by the lateral and medial articular menisci (biconcave cartilaginous plates). The medial meniscus in the region of the posterior horn (edge) is connected to the joint capsule by a rather loose connective tissue.

Figure 3 a. The mechanism of occurrence of pathological mobility during extension.

The presence of two anatomically isolated condyles complicates the ligamentous apparatus of the knee joint. In addition to the collateral ligaments of the knee joint, which play an important role in its stabilization, there are also cruciate ligaments (Fig. 1). The latter, located in the middle of the joint, prevent dorsoplantar mutual displacement of the femur and tibia due to the rounded shape of their condyles involved in the formation of the articular surfaces. On the dorsal surface of the knee joint there is a sesame-shaped bone (patella) enclosed in the tendon of the quadriceps muscle. When the quadriceps muscle of the reed is contracted, the kneecap slides along the block of the femur, while during the tension of the direct ligament of the kneecap, a force occurs that is transmitted to the crest of the tibia. Our studies on dissected limbs have established that if the knee joint is in a physiological half-bent position, the forces are decomposed according to the parallelogram rule, where the kneecap simultaneously exerts significant pressure on the femoral block. Under the influence of this pressure during the burden of the limb (supporting it on the substrate) in the conditions of fixation of the knee and hock joints by the gastrocnemius muscle, the femur could be displaced in the plantar direction, but this is mainly prevented by the anterior cruciate ligament. In extension of the knee joint of the hanging unencumbered limb, the tension of the direct ligament could not only rotate the tibia at its articulation with the femur, but also displace it dorsally in relation to the latter, but this is also mainly limited by the anterior cruciate ligament. It can be concluded that the most pronounced load on the anterior cruciate ligament at the most critical moments in the functioning of the knee joint predetermines its damage (Fig. 2).

Our anatomical and functional studies have shown that flexion and extension of the knee joint is associated with a constant tension of the anterior cruciate ligament. In this case, the main load occurs in connection with the opposition to the pressure of the patella, which it exerts on the block of the femur. It is logical to assume that one of the reasons frequent occurrence This pathology is the body weight and well-developed muscles of dogs. Data from a retrospective study among dog breeds show that the most common rupture of the anterior cruciate ligament occurs in Rottweilers, Staffordshire Terriers and Chowchow, which was respectively 17.65; 17.65 and 11.8% (Table 2).

Figure 4. Initial location of the biceps femoris.

Table 2. The frequency of occurrence of anterior cruciate ligament rupture of the knee joint among different breeds of dogs.

*Breed*	*Quantity* *dogs*	*Interest* (%)
1. rottweiler	15	17,65
2. Staffordshire terrier	15	17,65
3. chow- chow	10	11,8
4. mastiff	9	10,6
5. dobermanpinscher	6	7,0
6. Central Asian shepherd dog	5	5,9
7. Deutschgreat dane	4	4,7
8. east- Europeanshepherd dog	4	4,7
9. boxer	3	3,5
10. cocker- spaniel	3	3,5
11. Airedale	2	2,3
12. giant schnauzer	2	2,3
13. poodle	1	1,2
14. Frenchbulldog	1	1,2
16. pit bullterrier	1	1,2
17. Bordeauxgreat dane	1	1,2
18. Moscowsentry	1	1,2
19. Americanbulldog	1	1,2
20. Newfoundland	1	1,2
*Total* :	85	*100*

The study of the functional activity of the knee joint after an artificial rupture of the anterior cruciate ligament shows that with the contraction of the quadriceps femoris muscle during extension of the limb in the knee joint, both when moving it forward and while maintaining body weight, there is a mutual displacement of the femur and tibia in the plantar and dorsal directions, respectively. During knee flexion, reverse displacement occurs and the bones return to their anatomical position. correct position. In this regard, the main idea of the proposed method of surgical treatment is to enhance the function of the knee joint flexors by replanting the knee part of the tendon (pedicle) of the biceps femoris and the leg of the sartorius muscle on the crest of the tibia. This method of surgical operation prevents the negative effect of the quadriceps femoris muscle, which causes mutual displacement of the femur and tibia. To prevent abduction (abduction) of the limb, we displace the point of attachment of the leg of the sartorius muscle distally. The damaged anterior cruciate ligament is not restored, and we do not prosthetize it. As you know, antagonism muscle tissue manifested by the state constant voltage. Movement in the joints is provided by a synchronous increase in the tone of one muscle group and a decrease in the other. Thus, it can be assumed that when the knee joint is extended, the quadriceps femoris contraction occurs, which is simultaneously accompanied by greater resistance to relaxation of the biceps femoris muscle, which thereby prevents the tibia from shifting dorsally relative to the femur. Active dynamic stabilization of the knee joint by applying the proposed method of surgical treatment is confirmed by the fact that in recovered animals in the normal state, it is not possible to reproduce the symptom of the "anterior drawer", while during relaxation, as a rule, this is possible.

In addition to the replantation of the legs of the above muscles, the complete removal of fragments of the damaged ligament and medial meniscus from the joint, if possible, is of great importance. Without this, aseptic arthritis may continue despite anti-inflammatory therapy.

Having many years of experience in prosthetics of the cruciate ligament with a lavsan cord, it can be said with confidence that this material does not have sufficient strength to withstand the loads that continue to act in the knee joint after surgery. Malygina M.A. with co-authors indicates that "after the craze for lavsan plastic surgery for ligament restoration, disappointment came" due to the large number of complications. It cannot be said that in all dogs the lavsan ligament is ruptured, however, quite often the implant ruptures after a certain time and the problem recurs. At the same time, the method of extra-articular plasty proposed by us is more reliable in contrast to intra-articular plasty, an artificial material intended to replace the cruciate ligament.

It is impossible to ignore the increased risk of infection when a sufficiently massive implant is introduced into the cavity of the knee joint. In this regard, foreign material has to be removed, and the problem of restoring the dynamic function of the joint remains insoluble. Movshovich I.A. insists on the strictest observance of the rules of asepsis during the implantation of Dacron, which is difficult to implement in the real conditions of a veterinary clinic.

Figure 5. Movement of the leg of the biceps femoris to the crest of the tibia.

Replacement of the damaged anterior cruciate ligament of the knee joint with fascia flaps and other ligaments is also considered unpromising, as evidenced by studies in humanitarian medicine, which show that the implanted material deprived of blood supply atrophies, and a decrease in its strength inevitably leads to rupture. Klepikova R.A. in the experiment showed that the lengthening of the reimplanted flaps leads to repeated destabilization of the knee joint.

Using transposition of the biceps and sartorius muscles for anterior cruciate ligament rupture, we also observed several complications.

1. In one dog, on the fourth day after the operation, the reimplanted muscles were torn off from their attachment sites as a result of increased physical activity (the animal was attacked by another dog).

2. Two dogs showed signs of meniscus damage in the coming weeks after the operation, although this was not observed during the revision of the joint during the operation (repeated operation - meniscectomy ended with the recovery of patients).

3. Septic arthritis was observed in three dogs. In two, chasing occurred 1.5-2 months after the operation, when lameness was not observed in animals, and they passed exhibitions. At bacteriological examination two patients were isolated Staphylococcus aureus and one coli. Conducting rational antibiotic therapy made it possible to quickly cope with inflammatory process and restore limb function. In the third dog, the inflammation was complicated by damage to the articular cartilage and, although the septic process was eliminated, she continued to limp, despite additional treatment. The owner of the animal refused arthrodesis.

It should be noted that the operation according to the proposed method is possible, and it is better to use absorbable suture material, such as Dexon, Vicryl, and even catgut. This is due to the fact that there is no foreign material left in the operated area, which could, due to random circumstances, become a source of an infectious inflammatory process.

The data of a retrospective study, shown in Table 1, indicate that in 95.6% of the animals the function of the knee joint was completely restored, while in 3.8% of the dogs, the good functioning of the limb was associated with the need for periodic mild therapy. One unsatisfactory surgical outcome was associated with an accident.

Our own studies on the relationship between the age of animals and rupture of the anterior cruciate ligament do not give grounds to agree that the injury is preceded by degenerative changes in the knee joint. As can be seen from Table 3, the highest incidence of this pathology occurs at the age of 1 to 3 years, for which degenerative changes in the knee joints are doubtful.

Table 3. Incidence of Anterior Knee Ligament Rupture in Dogs by Age.

*Age*	*Quantity*	*Interest*
	*dogs*	*(%)*
1 year	9	10,6
2 of the year	29	34,1
3 of the year	17	20
4 of the year	10	11,8
5 years	7	*8,2*
6 *years*	9	10,6
7 years	1	*1,2*
8 years	3	*3,5*
*Total* :	85	*100*

On the contrary, in older individuals, for whom this type of joint damage is most common, rupture of the anterior cruciate ligament is quite rare. An additional argument against a secondary rupture of the ligament is usually the optimal condition of another, not injured, joint. The often observed sequential rupture of the anterior cruciate ligament, first in one and then in the other knee joint, in our opinion, is associated with an additional burden on the uninjured limb in the context of the continuing action of the same causative factors.

An analysis of the anamnesis obtained from the medical history in our clinic regarding the rupture of the anterior cruciate ligament in dogs shows that injuries in animals occurred in the same type and completely safe environment for their health. The resulting lameness, as a rule, was not accompanied by a visible deformity of the limb and any pronounced pain symptoms, which, in fact, was the main reason for the late appeal of animal owners for advice. It should be borne in mind that the news of a rather serious injury in their pets and the need for complex surgical intervention caused distrust among some owners. Despite the fact that the rupture of the anterior cruciate ligament of the knee joint is manifested by pathognomonic symptoms, the examination of the animal should be complete and requires a final diagnosis.

CONCLUSION

A long-term study of the results of treatment of anterior cruciate ligament rupture in 85 dogs by the method described above of reimplantation of the legs of the biceps femoris and sartorius muscles on the knee joint for 3 years allows us to draw the following conclusions:

1. The proposed method compared with prosthetic anterior cruciate ligament of the knee joint in dogs artificial materials and own tissues is the simplest and least time-consuming.

2. Inflammatory reaction in the postoperative period is less pronounced and manifests itself within a week.

3. Complete recovery of the operated limb generally occurs within 3-6 weeks from the date of the operation without the use of additional treatment.

4. Complications that arise do not affect the final result of treatment and are easily eliminated.

5. The result of the operation does not depend on the body weight of the animal and the conditions of its maintenance.

6. Excellent and nice results treatments that were obtained in 95.6% of the operated animals, as well as positive feedback from colleagues who have mastered the proposed method, allow us to recommend it for the treatment of anterior cruciate ligament rupture.

Literature

1. Akaevsky A.I. Anatomy of pets M., Kolos, 1975.

2. Klepikova R.A. Auto- and homotransplantation of fascia in the experiment: Abstract of the thesis. dis.cand. honey. Nauk.-M., 1966.-14 p.

3. Malygina M.A. and others. What is more important: the strength of the ligament prosthesis or its isometric location in the knee joint? Collection scientific works. Transplantation and implantation in surgery of large joints. Nizhny Novgorod. 2000, pp. 68-72.

4. Bags P.M. Plastic surgery of the ligamentous apparatus of the knee joint with various plastic materials: Abstract of the thesis. dis... cand.med.sci.- Baku.-1968.- 18 p.

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Magazine "Veterinarian" 6/2003