RU197909U1 - DEVICE FOR CARRYING OUT LOAD ON THE BALANCING APPARATUS AT THE X-RAY ANALOGICAL EVALUATION OF THE DEGREE OF INSTABILITY OF THE KNEE JOINT - Google Patents

Abstract

The utility model relates to the field of medicine, namely traumatology and orthopedics, and can be used for x-ray assessment of the degree of instability of the knee joint. The solution to this problem is provided by the fact that the proposed device contains two movable straps with two supporting moving along the entire length of the locking elements. Movable straps are connected to the main platform using ratchet mechanisms, allowing you to set a specific configuration of the straps for placement on the limbs. A mechanism is installed on the main site of the device, which creates pressure on the test segment of the limb. With a certain arrangement of the fixing elements at two points of the limb with pressure on the third point, radiographs are performed before and after the load, the difference in bone displacement is determined on the performed radiographs. 5 ill.

Description

The utility model relates to the field of medicine, namely to traumatology and orthopedics, and can be used for x-ray assessment of the degree of instability of the knee joint.

Known device for assessing the degree of instability of the knee ligament of the knee joint Telos Stress Device (Distribution of posterior tibial displacement in knees with posterior cruciate ligament tears Martin S. Schulz, Eric S. Steenlage, Kai Russe, Michael J. Strobel J Bone Joint Surg Am 2007 Feb ; 89), which consists of a frame fixing the lower leg; pulling element; scales; emphasis of a patella. The device has the following disadvantages. The design consists of many bulky heavy elements, the location of which must be alternately changed on the main frame during the study, depending on the side of the investigated limb.

A device for determining the instability of the knee joint, which contains a fixed and movable platform with a bracket. The bracket is connected by rods with bellows having spring valves for pressure limitation, and the fixed platform is connected with a displacement measurement indicator (RU 2199979, A61F 2/64, А61В 5/103, publ. 03/10/2003). The disadvantage of this solution are:

1. Bulkiness, technical complexity of the proposed design.

2. The inability to perform an X-ray examination in the frontal plane to diagnose instability of the knee joint caused by damage to the collateral ligaments of the knee joint.

A device for studying the anteroposterior instability of the knee joint is known, which comprises a bar with two supporting platforms and a measuring unit. The measuring unit has a sleeve with a lock made to move along the bar, a measuring rod moving in the sleeve with a sole with a division price of 1 mm and digitized through 5 mm, and a movable cylinder with a lock that allows you to set the zero position of the measuring rod. In the center of the proximal supporting platform there is a hole (RU 2336816, АВВ 5/103, publ. 10.27.2008). The disadvantage of this device are:

1. The inability to fix the displacement of the lower leg for x-ray examination before and after application of the load.

2. The inability to perform the same load on the limbs for a comparative study of the contralateral limb.

3. The inability to perform an X-ray examination in the frontal plane to diagnose instability of the knee joint caused by damage to the collateral ligaments of the knee joint.

The utility model is based on the task of creating a device for carrying out the load on the ligamentous apparatus during an X-ray assessment of the degree of instability of the knee joint, which provides an indivisible and universal principle of operation.

The result of the invention is achieved in that the device comprises two movable slats with two supporting moving along the entire length of the elements to the limb. Movable straps are connected to the main platform using ratchet mechanisms that allow you to set a specific configuration of the straps for placement on the limbs. A mechanism is installed on the main site of the device, which creates pressure on the test segment of the limb. With a certain arrangement of the fixing elements at two points of the limb with pressure on the third point, radiographs are performed before and after the load, the difference in bone displacement is determined on the performed radiographs.

The figures depict:

The design of the device is illustrated in FIG. 1, which shows a diagram of the proposed device, the numbers indicate:

1. main site;

2. ratchet mechanism for moving the slats;

3. a mechanism that creates pressure;

4. movable slats;

5. elements fixing the limb;

FIG. 2 is a schematic illustration of a device arrangement for assessing the degree of instability of a knee joint in case of damage to the anterior cruciate ligament;

FIG. 3 is a schematic illustration of a device arrangement for assessing the degree of instability of a knee joint in case of damage to the posterior cruciate ligament;

FIG. 4 is a schematic illustration of the layout of a device for diagnosing the degree of instability in case of damage to the medial collateral ligament;

FIG. 5 is a schematic illustration of the arrangement of a device for diagnosing the degree of instability in case of damage to the lateral collateral ligament.

Use the device as follows.

For X-ray assessment of the degree of instability of the knee joint caused by damage to the anterior cruciate ligament, the apparatus is fixed on the lower extremity so that the movable straps are fixed on the front surface of the lower leg in the lower third and on the patella, the mechanism that creates pressure is fixed on the back surface of the lower leg in the upper third , the knee joint is bent 90 degrees (front drawer test) or 30 degrees (Lachman test). Perform an x-ray of the joint without effort. Using the mechanism that creates pressure, the tibia is advanced anteriorly. Perform an x-ray with the created force. According to the performed x-rays, the difference in the displacement of the lower leg in millimeters is determined.

The results are compared with a study performed on the contralateral limb. The difference in the displacement up to 5 mm is taken as instability of the I degree, from 5 to 10 mm - II degree, more than 10 mm - III degree.

CLINICAL OBSERVATION

III, 20 years old, received an injury to the right knee joint 04/01/2017 - sprained his leg when playing soccer. When testing on the proposed device revealed: the difference in the displacement of the tibia anteriorly (test "front drawer") between a healthy and damaged limb was 12 mm, which corresponds to instability of the III degree. Based on the obtained data, a rupture of the anterior cruciate ligament of the right knee joint with acute instability of the III degree was diagnosed. Surgical treatment was performed - autoplasty of the anterior cruciate ligament of the right knee joint with tendons of semi-tendon and tender muscles with nortical graft fixation. 20 days after the operation, a control test of the knee joints for stability was performed: the difference in the anterior tibia displacement (anterior drawer test) between a healthy and damaged limb was 4 mm, which corresponds to residual instability of the first degree. There were no complications.

The device is used in the treatment of 12 patients. Such a device for measuring instability in the published scientific literature was not found.

Claims (1)

A device for carrying out the load on the ligamentous apparatus during an X-ray assessment of the degree of instability of the knee joint, characterized in that it includes two movable slats with two supporting moving along the entire length of the elements on the limb, while the movable straps are connected to the main platform using ratchet mechanisms, and on the main The device’s platform is equipped with a mechanism that creates pressure on the test segment of the limb.

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