Damage of anterior cruciate ligament

For several decades, work has been carried out to study the results of arthroscopic treatment of damage to the capsular-ligament apparatus of the knee joint.

Despite the variety of arthroscopic methods of treatment of anterior posttraumatic instability of the knee joint, a significant percentage of unsatisfactory results remains, the most important causes of which are complications resulting from errors at the stages of diagnosis, surgical treatment and rehabilitation of patients with anterior posttraumatic instability.

In the literature, the possible complications after arthroscopic treatment of anterior post-traumatic instability are rather widely discussed. However, little attention is paid to the analysis of their causes and methods for their correction.

[1], [2], [3], [4], [5], [6], [7]

Epidemiology

The problem of treating patients with knee pathology remains to this day important and one of the most difficult in traumatology . The knee joint is the most commonly injured joint, it accounts for up to 50% of all joint injuries and up to 24% of injuries of the lower limb.

According to various authors, ruptures of cruciate ligaments of the knee joint are met with a frequency of 7.3 to 62% among all injuries of the capsular-ligament apparatus of the knee joint.

[8], [9], [10], [11], [12], [13],

Diagnostics of the anterior cruciate ligament injury

All patients before the primary surgery performed a clinical and radiological examination. Performing anamnesis, examination, palpation, clinical testing of injuries of the knee structures, radiography, general blood and urine analysis, biochemical blood and urine tests. According to the indications, the following instrumental studies are performed: testing on the CT-1000, CT, MRI, ultrasound. Diagnostic arthroscopy immediately precedes operative treatment.

The examination of the patient begins with the clarification of complaints and the collection of anamnesis. It is important to determine the mechanism of damage to the lumbar and ligament apparatus of the knee joint and collect information about the transferred operations on the knee joint. Further, the examination, palpation, measurement of the circumference of the joint, determine the amplitude of passive and active movements, also widely use the Lysholm questionnaire for athletes and a 100-point scale developed at CITO for patients with less physical ambitions.

Evaluation of the functions of the lower extremities is carried out according to the following parameters: complaints of instability in the joint, the possibility of actively eliminating the passively prescribed pathological shank displacement, ability to function, lameness, the performance of special motor tasks, maximum strength of the periarticular muscles with prolonged operation, hipotrophy of the hip muscles, muscle tone, pain in the joint, the presence of synovitis, the correspondence of motor abilities to the level of functional claims.

Each attribute is assessed on a 5-point scale: 5 points - no pathological changes, compensation of functions; 4-3 points - moderately expressed changes, subcompensation; 2-0 points - pronounced changes, decompensation.

Evaluation of treatment results includes three degrees: good (more than 77 points), satisfactory (67-76 points) and unsatisfactory (less than 66 points).

One of the criteria for subjective evaluation of treatment outcomes is the patient's assessment of his functional state. The condition of a good result is the restoration of functional capacity. Without this, the results of treatment are considered satisfactory or unsatisfactory.

At a clinical examination, the volume of movements is assessed and stability tests are performed. It is always important to eliminate the symptom of the front drawer.

Patients complain of pain and / or feelings of instability in the joint. Pain can be caused by the very instability or associated damage to the cartilage or meniscus. Some patients can not remember the previous damage, suddenly in months or years pay attention to the knee joint. Patients rarely describe the knee joint as unstable. They usually describe the uncertainty, looseness, the inability to control movements in the damaged joint.

Characteristic crepitation under the patella due to biomechanics in the patellofemoral articulation.

Often dominant are secondary symptoms: chronic effusion in the joint, degenerative changes in the joint or cyst of Baker.

Also important is the state of active-dynamic stabilizing structures both before and after operation. This is due to the achievement of a fairly reliable stabilizing effect due to the periarticular muscles.

Great importance is attached to the indicator of muscle strength.

To diagnose anterior instability and evaluate the long-term results of its treatment, the most informative tests are used: the symptom of the front drawer in the neutral position of the shin, the abduction test, the adduction test, the Lachman test.

An important indicator of the functional state is the ability to actively eliminate the passively prescribed pathological displacement of the tibia relative to the hip.

From special motor tasks we apply walking, running, jumping, climbing stairs, squats, etc.

Mandatory consideration is given to the endurance of the periarticular muscles during prolonged work.

The passive testing system includes a symptom of an anterior drawer in three shin positions, abduction and adduction tests at 0 and 20 degrees of inflexion in the joint, a recurvement test and a lateral change of the fulcrum, a Lachman-Trillat test, and a measurement of the abnormal shank rotation.

The active testing complex includes an active test of the front drawer in three positions of the tibia, active abduction and adduction tests at 0 and 20 ° flexion in the joint, active Lachman test.

To determine the damage or inferiority of the anterior cruciate ligament, the symptom of the anterior "drawer" is used - the passive shin displacement (anterior translation), also with different flexion of the tibia. Recommend to focus on one of the most accepted, according to the literature gradations of this symptom: I degree (+) - 6-10 mm, II degree (++) -11-15 mm, III degree (+++) - more than 15 mm .

In addition, the symptom of the front "drawer" should be evaluated with a different rotational installation of the shin - 30 °, external or internal rotation.

The Lachman symptom is recognized as the most pathognomonic test for the detection of anterior cruciate ligament injury or its transplant. It is believed that it gives the greatest information about the condition of the anterior cruciate ligament in acute injury to the CS, since when it is performed, there is almost no muscle resistance to anteroposterior translation (displacement) of the tibia, and also with chronic instability of the CS.

Lachman-test is performed in the position lying on the back. Evaluation of the Lachman test is performed in terms of the size of the anterior displacement of the tibia relative to the femur. Some authors use the following gradations: I degree (+) - 5 mm (3-6 mm), II degree (++) - 8 mm (5-9 mm), III degree (+++) - 13 mm (9- 16 mm), IV degree (++++) - 18 mm (up to 20 mm). In an effort to unify the evaluation system, we use a three-degree gradation similar to that previously described for the symptom of the front drawer.

The symptom of a change in the point of rotation, or the symptom of anterior dynamic subluxation of the lower leg (pivot shift-test), is also attributed to symptoms pathognomonic for anterior cruciate ligament injury, to a lesser degree it is characteristic for combination with rupture of internal lateral ligamentous structures.

Testing is carried out in the position lying on the back, the muscles of the legs should be relaxed. One arm grasps the foot and turns the shin inward, the other is located in the region of the lateral condyle of the thigh. With slow bending of the COP to 140-150 °, the hand feels the appearance of anterior subluxation of the tibia, which is eliminated with further bending.

Pivotshift test no Macintosh is performed in a similar patient position. One hand produces the inner rotation of the shin, and the other - valgus deviation. With a positive test, the lateral part of the articular surface of the tibia (outer plateau) is displaced anteriorly, with a slow bending of the CS to 30-40 °, its reverse bias occurs. Although they believe that the pivot shift test is pathognomonic for the inferiority of the anterior cruciate ligament, it can be negative in the event of damage to the orotibial tract (ITT), a full longitudinal rupture of the medial or lateral meniscus with the dislocation of its body (a "handle leukemia"), expressed by a degenerative process in the lateral part of the joint, hypertrophy of the tubercles of the intercondylar elevation of the tibia, and others.

The active Lachmann test can be used for both clinical examination and X-ray examination. If the anterior cruciate ligament is damaged, the anterior displacement of the tibia reaches 3-6 mm. Testing is carried out in the position lying on the back with fully straightened legs. One hand is placed under the thigh of the limb to be examined, bending it at the knee joint at an angle of 20 °, and using the brush to grasp the CS of the other leg so that the thigh of the limb being examined lies on the forearm of the researcher. Another brush is placed on the front surface of the ankle joint of the patient, his heel is pressed against the table. Then the patient is asked to stretch the quadriceps muscle of the thigh and closely follows the movement of the tuberosity of the tibia anteriorly. When it is displaced by more than 3 mm, the symptom is considered positive, indicating a damage to the anterior cruciate ligament. To determine the state of medial and lateral joint stabilizers, a similar test can be performed with the inner and outer rotation of the shin.

Radiography

Radiography is carried out according to the standard method in two standard projections, as well as functional radiographs.

When evaluating images, the position of the patella, the tibiofemoral angle, the convexity of the lateral tibial plateau, the concavity of the medial, dorsal fibula in relation to the tibial angle are taken into account.

Radiographs allow you to assess the overall condition of the knee joint, identify degenerative changes, determine the bone state, the type and position of the metal structures, the location of the tunnels and their expansion after the operative treatment.

Of great importance is the experience of the doctor, as the evaluation of the images is rather subjective.

Lateral radiographs should be performed at 45 ° flexion in the joint for a correct evaluation of the relationship between the tibia and the patella. To objectively assess the rotation of the tibia, it is necessary to superimpose the lateral and medial condyle of the tibia on each other. The height of the patella is also assessed.

Insufficient extension is easier to diagnose in the lateral projection, the patient lies with a pierced leg.

To determine the axis of the limb, additional radiographs in a direct projection on long cassettes are required in the patient's standing position, since there are abnormalities in the deforming arthrosis. The anatomical axis of the limb, defined by the longitudinal orientation of the thigh to that of the shin, averages 50-80 °. This is the most important point in the course of further surgical treatment (corrective osteotomy, arthroplasty, endoprosthetics).

The degree of shin displacement relative to the femur in the anteroposterior and medial-lateral direction is determined using functional radiographs with a load.

In chronic anterior instability of the knee joint, characteristic radiographic signs are noted: narrowing of the intercondylar fossa, narrowing of the articular space, presence of peripheral osteophytes on the tibia, upper and lower pole of the patella, deepening of the anterior meniscus groove on the lateral condyle of the thigh, hypertrophy and acuity of the ligament of the intercondylar elevation.

The lateral radiograph often indicates the reason for the limitation of mobility. The lateral radiograph with maximum extension may indicate insufficient extension, while assessing the position of the tibial tunnel relative to the intercondylar arch, which looks like a linear compaction (line Blumensaat).

[14], [15], [16], [17], [18], [19], [20]

CT scan

CT is not considered routine research. CT is performed in patients with insufficient information in other types of examination, especially in the case of compression fractures of the tibial condyles.

With the help of CT, bone and cartilaginous lesions are well visualized. With CT, it is possible to perform various dynamic tests with flexion in the knee joint at different angles.

[21], [22], [23], [24], [25]

KT-1000

To measure anteroposterior displacement of the tibia, the KT-1000 apparatus is used.

The CT-1000 is an arthrometer, it consists of the meter of the front-to-back displacement of the tibia relative to the femur and the supports for the lower thirds of the hips and feet. The device is attached to the shin with the help of Velcro straps, and the existing touch pad presses the patella to the front surface of the femur. In this case, the joint gap should be combined with the line on the apparatus. The lower limb located on the stands is bent at the knee joint within 15-30 ° to measure the front shank displacement and 70 ° to measure the posterior displacement of the tibia relative to the femur.

First, the injured knee joint is tested. To measure the anterior bias of the tibia, the doctor pulls the handle located in the antero-top part of the device toward himself and tries, holding the touch pad on the patella, to make a forward displacement of the shin. At the same time apply force of 6, 8 and 12 kg, which is controlled by sound signals. At occurrence of each sound signal the doctor marks a deviation of an arrow on a scale and records indications of the device. Shin displacement relative to the thigh is expressed in millimeters. Further, the doctor tests the posterior displacement of the lower leg by flexing it in the knee joint to an angle of 70 ° and makes by means of the handle of the apparatus an attempt to shift the shin to the back. The sound signal, which occurs when the arrow is deflected, indicates the amount of posterior displacement of the tibia relative to the femur.

Similar testing is performed on a healthy knee joint. Then, a comparison and subtraction of the corresponding data from the healthy and damaged knee joints is performed. This difference shows the amount of anterior displacement of the tibia relative to the femur at a load of 6, 8 and 12 kg.

The forward displacement is determined at a flexion angle of the shin 30 °.

When the difference in the value of the front displacement at 67N and 89N of the affected and healthy joint is more than 2 mm, a rupture of the anterior cruciate ligament is suspected.

There are certain principles of instrumental testing in the instability of COP. It is necessary to consider the following parameters: the degree of rigidity of fixation of the limb by belts, the location of sensor sensors on the joint, the complete relaxation of the leg muscles, the location of the arthrometer in relation to the joint gap, the degree of rotation of the shank, the weight of the leg, the angle of flexion in the knee joint.

In the acute period after the injury, the use of an arthrometer is inadvisable, since it is impossible to completely relax the periarticular muscles. It is necessary to choose the neutral position of the shin correctly, taking into account the internal rotation during the forward displacement of the shin, while the external rotation occurs at the outer shank. Otherwise, the amount of anteroposterior translation will be less than the true value. In order to obtain the maximum value of the abnormal shank displacement, it is also necessary to allow its free rotation.

The degree of translation depends on the magnitude of the applied force, the point of its attraction and direction.

The use of footstools should not restrict the shin rotation. It is necessary to locate the sensor sensors, strictly focusing on the articular fissure, since if they are distally displaced, the readings will be less than the true value, if proximally, then more.

An obligatory condition for an objective evaluation is the fixation of the patella in the intercondylar sulcus. For this, it is necessary to give the tibia an angle of flexion in the joint of the order of 25-30 °. With congenital and post-traumatic subluxations of the patella, the angle of flexion is increased to 40 °. With the front instability, the angle of flexion in the joint is 30 °, with the back - 90 °.

Two audio signals accompany the testing: the first - with a load of 67N, the second - at 89N. Sometimes, to determine the rupture of the anterior cruciate ligament, greater force is needed.

Normally, the difference between the two extremities when testing anteroposterior displacement does not exceed 2 mm, sometimes indicating a value of less than 3 mm as at the limit of normal.

Take into account the index of forward compliance, that is, the difference between the offset at 67N and 89N. This value should also not normally exceed 2 mm.

With a displacement of more than 2 mm, we can speak of a rupture of the anterior cruciate ligament (anterior cruciate ligament transplant).

I would also like to note that with the instability of both knee joints or hypermobility, the use of the CT-1000 arthrometer is impractical.

In conclusion, it should be said that when using this arthrometer, of course, there is an element of subjectivity, depending on a number of parameters, including the researcher. Therefore, the examination of patients should be carried out (if possible) by one doctor.

With the help of KT-1000, one can only ascertain the anteroposterior displacement of the tibia relative to the femur, and no lateral instability is recorded.

Magnetic resonance imaging

MRI is the most informative of non-invasive research methods, allowing to visualize both bone and soft tissue structures of the knee joint.

A healthy anterior cruciate ligament should look less intense on all images. Compared to the denser posterior cruciate ligament, the anterior cruciate ligament can be slightly non-homogeneous. In connection with its oblique direction, many prefer to use oblique coronary images. When the anterior cruciate ligament ruptures, the MRI allows you to visualize the location of the lesion.

The anterior cruciate ligament is well visualized on the lateral sections during extention and external rotation of the tibia. The anterior cruciate ligament is brighter than the posterior cruciate ligament, the fibers of the anterior cruciate ligament are twisted. The absence of continuity of fibers or their chaotic orientation indicates the ligament rupture.

A complete rupture of the anterior cruciate ligament is diagnosed more by indirect signs: anterior tibial displacement, excessive posterior incline of the posterior cruciate ligament, an undulating contour of the anterior cruciate ligament.

Ultrasonography

Advantages of ultrasound - low cost, safety, speed, highly informative image of soft tissues.

Ultrasound allows to study the state of the soft tissues of the knee joint, the surface of bone and cartilage, and also to reduce the echogenicity of the edema of tissues, the accumulation of fluid in the joint cavity or periarticular formations. Ultrasound is used to detect injuries of meniscuses of the knee joint, collateral ligaments, soft tissue structures surrounding the knee joint.

Arthroscopy

In diagnostic arthroscopy, the authors use standard approaches: anterolateral, anteromedial, upper parietal lateral.

Arthroscopic examination of the anterior cruciate ligament includes evaluation of the appearance of the anterior cruciate ligament, the integrity of the synovial ligament of the ligament, the orientation of the collagen fibers not only at the tibial attachment site of the ligament, but also along its length, especially at the site of the femoral insertion. If in cases of damage to the anterior cruciate ligament during and at the tibial attachment site with detachment of the bone fragment arthroscopic diagnosis is not particularly difficult, then the diagnosis of intrasynovial (intramuscular) fresh and chronic lesions of the anterior cruciate ligament presents great difficulties. This is due to the fact that the outward, at first glance, front cross-shaped ligament appears to be whole: the synovial membrane is whole, the palpation of the anterior cruciate ligament with an arthroscopic crochet reveals the presence of a full structure and thickness of the ligament, the arthroscopic symptom of the front "drawer" shows sufficient tension of the ligament fibers. However, a more careful study of the capillary network in the middle and femoral parts of the ligament, as well as the opening of the synovial sheath of the ligament, makes it possible to determine the damage to the ligament fibers and the presence of hemorrhages or scar tissue. The secondary sign of the old intrasynovial damage of the anterior cruciate ligament is the hypertrophy of the synovial and adipose tissue on the femoral part of the posterior cruciate ligament and the arch of the intercondylar thighbolt (symptom of "tissue gain").

Sometimes only arthroscopically it is possible to fix the following types of damage to the anterior cruciate ligament:

• damage to the anterior cruciate ligament in the femoral attachment site with and without stump formation;
• Intrasynovial anterior cruciate ligament injury;
• damage to the anterior cruciate ligament throughout;
• in rare cases - damage to the anterior cruciate ligament in the region of intercondylar elevation with detachment of the bone fragment.

[26], [27], [28]

Treatment of the anterior cruciate ligament injury

With compensated form of anterior instability of the knee joint, the treatment consists in immobilization with subsequent restoration of joint mobility and the functions of active stabilizers (muscles).

With subcompensated and decompensated forms of anterior instability, there is a need for surgical intervention aimed at restoring the integrity of primarily static stabilizers. The complex treatment necessarily includes functional treatment to enhance active stabilizers.

It should also be noted that as a result of the medical measures, mainly with an anteromedial form of instability, transitions from the subcompensated to the compensated form are possible, since this anatomical region has the largest number of secondary stabilizers, which has a favorable effect on the result of treatment.

Management of patients with anterior instability of the knee depends on many factors: age, type of professional activity, the level of athletic training, concomitant intraarticular injuries, the degree of instability, the risk of repeated damage, the time from the time of injury. First of all, the plastic restoration of the anterior cruciate ligament during rupture is indicated to professional athletes, especially with concomitant injuries of other structures of the knee joint. Also, the reconstruction of the anterior cruciate ligament is recommended for chronic instability of the knee joint.

Indications for anterior arthroscopic static stabilization are primary and recurrent subcompensated and decompensated forms and types of anteromedial (A2M1, A2M2, AZM1, AZM2, AZMZ) and anterolateral (A2L1, A2L2, A2L3, AZ2, A2L2, A2L3, AZ1, A2L2, A2L3) instability, the inability to compensate for pathology with conservative methods treatment.

The decision on plastic recovery of the anterior cruciate ligament in patients older than 50 years is taken depending on the age and level of physical activity of the patient, the degree of deforming arthrosis. Plastic anterior cruciate ligament is recommended in the case of a strong restriction of physical activity due to instability of the knee joint.

In each individual case, the decision on surgical treatment is made taking into account the individual characteristics of the patient.

Contraindications to static stabilization are the following conditions and diseases:

• presence of gonarthrosis of III-IV degree;
• pronounced hypotrophy of the hip muscles;
• contracture of the joint;
• term after injury more than 3 days and less than 3 weeks;
• infectious diseases;
• osteoporosis;
• thrombosis of the vessels of the lower limb.

At a stage of definition of indications and contraindications to operative treatment of anterior posttraumatic instability, a dilemma sometimes arises. On the one hand, the consequences of chronic instability (hipotrophy of the hip muscles, deforming arthrosis) become contraindications to the performance of static stabilization and arthroscopic stabilization using grafts with bone blocks leads to an increase in the load on the articular cartilage (as a consequence - to the progressing deforming arthrosis). On the other hand, conservative methods do not provide a sufficient stabilizing effect, which also contributes to the development of deforming arthrosis.

Sometimes it is recommended to postpone the operation to an increase in the volume of movements in the knee joint, which may take 2-3 weeks. Postponement of surgery in the acute phase leads to a reduction in complications during rehabilitation measures associated with the restoration of the volume of movements in the knee joint after surgical treatment.

The choice of autograft and method of fixation

To restore the anterior cruciate ligament, autografts from the patellar ligament, the tendons of the semimembranous and tender muscles, in rare cases the Achilles tendon and the quadriceps tendon are most often used. The central third of the patellar ligament with two bone blocks remains the most common autograft for the reconstruction of the anterior cruciate ligament in athletes. A quadriceps tendon with a single bone block or without a bone block is increasingly being used as an autograft to replace the anterior cruciate ligament. The most frequently used autologous material for transplantation of the anterior cruciate ligament in the CITO is the central third of the patellar ligament. This transplant has two bone blocks (from the patella and tuberosity of the tibia) to provide a primary, reliable, rigid fixation, which contributes to early loading.

The advantages of an autograft from a patellar ligament are as follows.

• Normally, the width of the patellar ligament allows for autografting of any desired width and thickness. Usually the transplant has a width of 8-10 mm, but sometimes, in cases of repeated reconstruction, the necessary width can reach 12 mm.
• The patellar patch is always available as an auto material and has minor anatomical variations. This makes it possible at any time to make a technical sampling of the auto material technically.
• Bone blocks allow the transplant to be firmly fixed, for example, with intervening screws, by screwing them between the bone block and the wall of the bone tunnel. This method provides a very high primary fixation.

The use of an autograft from the tendons of the semitendinous and tender muscles, according to several authors, increases the pathological external rotation of the shank to 12%. The success of the reconstruction of the anterior cruciate ligament depends significantly on the biological remodeling of the graft.

In connection with the removal of the ligament strips with bone blocks from the patella and tuberosity of the tibia, this area becomes painful. Although the bone defect can be closed with a spongy bone, it is not always possible to adequately cover the defect with soft tissues, especially if the primary damage provoked scar formation around the tendon.

Since the bone block is taken from the tuberosity of the tibia, which is important for resting on the knee, some patients (wrestler wrestlers, artists, priests, etc.) can complain of pain during direct loading on the knee joint or the inability to rest on the knee. There are observations when the patient does not complain about instability of the knee joint and the lack of limb functions after the operation, but because of this complication he is forced to abandon or restrict his usual professional activity. Therefore, a good result is based not only on stability.

In the clinic of sports and ballet injuries CITO prefer to use autografts from a patellar ligament with two bone blocks and fixing them with interferential screws.

The anterior static stabilization of the knee joint with a free autotransplant from the patellar ligament is performed following a diagnostic arthroscope to determine the extent and types of intervention.

Autograft sampling is usually performed on the ipsilateral limb for preservation of the contralateral as a supporting one. First, the bone block is taken from the tuberosity of the tibia, then from the patella. One of the bone blocks should be massive enough to fix it in the femoral tunnel.

To reduce the chances of splitting the bone block and the amount of damage in the donor site, the bone fragments of the trapezoidal autograft are taken; such a bone block is easier to handle with a squeezing ticks, which gives the graft a round shape, with less risk of a patella fracture.

Such an autograft is easier to install in the intraosteal tunnels. The autograft is cut off first from the tuberosity of the tibia, then from the patella.

With the help of arthroscopic clamps, the bone blocks are attached to a rounded shape

Simultaneously with the preparation of the autograft, the optimal (isometric) position of the tibial tunnel is determined. To do this, use a special stereoscopic system (the angle of the stereoscopic system is 5.5 °). The tunnel is centered, focusing on the remaining tibial part of the anterior cruciate ligament, and in its absence - on the area between the tubercles of the intercondylar elevation or 1-2 mm behind them.

Its diameter varies depending on the size of the autograft (it should be 1 mm larger than the diameter of the transplant). In succession, the specified diameter of the drill is formed by the intraosseous tunnel (strictly on the spoke, otherwise there will be an extension of the canal). The joint is washed abundantly to remove bone chips. Using the arthroscopic rasp, the edges of the exit of the tibial canal are smoothed.

In the next step, using the drill, a femoral insertion point is determined on the outer condyle of the hip (5-7 mm from the posterior margin) for the right knee joint at 11 hours. When revisions are reconstructed, as a rule, an "old" channel with minor variations in its position is used. Using the cannulated drill, the femoral canal is drilled, its depth should not exceed 3 cm. After finishing the canal, the edges of the femoral canal are treated with an arthroscopic rasp.

In some cases, plasticity of the intercondylar notch is produced (gothic arch, intercondylar scrap ramp).

Before the autograft in the bone tunnels from the joint cavity, all bone-cartilaginous fragments are removed with the help of arthroscopic clamping and thorough flushing of the joint.

The stitched transplant is carried out in the intraosteal tunnels and fixed in the femoral tunnel by an interferential screw.

After fixing the femoral end of the graft, the joint is washed with antiseptics to prevent purulent complications.

Then the operated lower limb is completely unbent and performs fixation in the tibial canal, necessarily with full extension of the knee joint. The filaments are stretched along the channel axis, the arthroscope is inserted into the lower tibial portal, the point and the direction of fixation by the screw are determined with the help of the needle (if the bone tissue in this region is solid, the sword is injected). When screwing the screw in position and tension of the threads follow the displacement of the bone block, so that it is not pushed out of the canal into the joint cavity. In the next step, the arthroscope visualizes if the bone block does not protrude into the joint due to its displacement along the channel axis when the screw is twisted (therefore, it is better to use a self-tensioning screw), then, by means of an arthroscope, the degree of adherence of the bone block to the bone tunnel wall is evaluated, then the screw is screwed completely.

If the original length of the autograft with bone blocks exceeds 10 cm, there is a high probability of protruding the bone block from the tibial canal to the outside.

To avoid post-operative pain in the patellofemoral joint after fixation, the protruding part of the bone block is bored.

Before closing the soft tissues with a rasp smooth out the sharp protruding bone edges and corners, and then suture soft tissue.

Next, carefully inspect the area of the tibial screw for bleeding, if necessary, perform thorough haemostasis with the help of coagulation.

Control radiographic shots in two projections are performed directly in the operating theater.

Wounds are sutured layer by piece tightly, do not recommend installing drainage, as it becomes the gateway to infection; if necessary (appearance of effusion in the joint) the next day, puncture the joint.

On the operated limb impose a postoperative brace with a lock 0-180 °.

After the operation, a cold system is applied to the joint, which significantly reduces the number of complications such as paraarticular edema and effusion in the joint.

For the first time in Russia, a more universal method of fixing autografts with polyamino acid pins from the Rigidfix system and the last-generation Mi-La-Gro interjection screw for grafts with bone blocks was launched in Russia at CITO. The versatility of the method lies in its application to soft tissue transplants and to grafts with bone blocks. Advantages of the method are the absence of danger of damage to the soft tissue part of the autograft with bone blocks at the time of fixation, rigid fixation, no problems with the removal of fixing pins due to their resorption. The stiffness of the primary fixation and the tight fit of the bone graft blocks are provided by the swelling of the pins and the resulting compression.