RU2837346C1 - Method for eliminating periarticular valgus-varus deformities at level of knee joint in young children using orthopaedic apparatus - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to traumatology and orthopaedics, and can be used for elimination of periarticular valgus-varus deformities at the level of knee joint in children with application of orthopaedic apparatus. Elimination of deformation is carried out using the device presented in figure 1. Attachment elements of the device, made in the form of detachable sleeves, are applied and fixed on the patient’s hip and shin so that the fixed hinge is located along the axis of movement of the joint of the patient’s extremity in the position of the existing flexion contracture of the joint, which is eliminated discretely, by manual extension of the knee joint by the detachable sleeves, by rotating the plates of the fixed hinge relative to each other when the threaded connection is loosened along the axis of rotation of the joint. Rate of extension correction per day is equal to a turn through the width of one tooth. Process is continued until the contracture is eliminated, after which the valgus, or varus, deformation is eliminated with the position of the hip and shin removed to the anatomically correct position of the physiological axis of the extremity, rate of distraction in first 10 days is 1 mm a day on the concave side of deformation and is provided by turning the nut installed in the bracket for one turn. Distraction rate is then reduced to 0.25 mm a day, which corresponds to a turn of said nut by 1/4 of a turn. Simultaneously, the extremity is loaded. Unloading insole made of foam plastic is inserted into the patient’s shoes, the shape of which in the cross section has the form of a right-angled triangle having a hypotenuse at the base, and in the case of valgus deformity, the vertex of its smaller angle is turned to the outer side of the foot, and in case of varus deformity – inward. As the deformation is corrected, the deformation angle decreases, the load is increased, and the shape of the unloading insole is corrected by cutting its angle at the vertex facing the side opposite to the deformation. At onset of pain syndrome rate of distraction is reduced, taking break for 2-3 days.

EFFECT: method provides reducing the length of treatment, reducing the number of injuries of the intervention, the absence of recurrent deformities, while improving the anatomical and functional outcomes of the treatment ensured by the physiological, non-traumatic elimination of the axial deformation in young children using the Ilizarov effect.

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Description

The invention relates to medicine, namely to orthopedics, and is intended to eliminate valgus-varus deformity at the level of the knee joint in young children.

It is known that most often knee joint deformations are formed as complications in acute hematogenous osteomyelitis or other diseases of the musculoskeletal system, as a result of damage to the metaphyseal growth zone of the femur, or tibia, as well as in the destruction of one of the condyles of the femur, or tibia. It is well known that the percentage of orthopedic complications, and the severity of deformations, or destructions, would be much lower if, along with surgical and antibacterial treatment, patients simultaneously received orthopedic assistance in the form of corrective tutors, or at least plaster casts.

Axial periarticular valgus and varus deformities of the lower extremities in children under 5 years of age (younger age) are formed after acute hematogenous osteomyelitis, "early" and "late" rickets, and in connective tissue dysplasia syndrome, in the form of osteochondrodysplasia with hypermobility of the hip and knee joints. In "early" rickets, at the age of up to 1 year, in the absence of static-dynamic load of body weight when walking, axial periarticular deformities of the legs begin to form only under the influence of muscle traction. In "late" rickets, axial deformities of the legs in children appear when the child begins an active supporting load of walking, and always progress rapidly due to the emerging dystrophy of the growth zones [1]. Osteochondrodysplasia leads to axial disorders of the extremities most often in the first period of intensive growth of the child, that is, at 2-3 years.

Axial periarticular deformations in the hip joint area lead to the formation of coxa vara and coxa valga, and in the knee joint area to genu varum and genu valgum [2].

In children over 5 years of age, surgical methods of correction of valgus-varus deformities of the knee joint are mainly offered, which are performed by means of corrective osteotomy, or corticotomy, the difference lies in the level of its implementation, or form [3]. However, this type of intervention is traumatic, relapses of the disease are not excluded. It should be noted that all known methods of surgical correction of valgus-varus deformities of the knee joint are an extreme measure in the treatment process. It is inappropriate, and sometimes simply dangerous, due to the resulting trauma to the growth zones in the growing child's body, to immediately use such surgical treatment as osteotomy, without making sure that the deformation can be corrected by conservative methods.

A conservative method of correcting tibia deformities in children is known, which consists in the fact that preschool-age children with valgus deformity of the tibia over 15°, or with varus deformity, when the distance between the medial malleoli with closed knee joints is over 3-4 cm, undergo daily correction using redressing exercises, followed by the application of a polywick tutor. Then, as the deformity is eliminated, the tutors are warmed up in a water bath and molded to the shape of the patient's limb. During the treatment, the patient wears tutors for 2-2.5 months. After eliminating severe deformities of the tibia, the tutor is replaced with an orthopedic device, which provides for molding the sleeves of the tibia and thigh to the patient's limb, in which the patient wears for 1 year [4].

However, due to persistent muscle contracture and ligament shortening, even with daily retraining exercises, it is not always possible to achieve a quick and immediate correction of axial deformation. Most often, in order to normalize limb growth while simultaneously eliminating axial deformation, it is necessary to apply dosed corrective efforts, gradually increasing them, without the supporting load of walking. Only after complete elimination of axial valgus, or varus, deformation can orthopedic tutors be made that fix the knee joints in the correct position and allow the supporting load of walking.

The closest method to the claimed one, in its technical solution, is the method of normalizing the growth of lower limbs in children with axial deformations [5], in which the correction of axial deformation and "normalization of the growth of lower limbs" are implemented by installing and fixing a rigid spacer between the knee joints with valgus deformation, and a soft pad between the ankle joints, and the size of the rigid pads, with a decrease in axial deformation, is also reduced. Gradual elimination of the asymmetry of the axial load on the epimetaphyseal zone of the growth articular cartilage, due to the muscular-tonic force of traction of the leg muscles, normalizes the growth of the limb. Only after obtaining a stable correction of the axial deformation of the limb axis is the supporting load of walking allowed in an orthopedic tutor with a knee hinge.

However, the cause of deformation in any disease or injury is the hypofunction of the outer (development of valgus) or inner (development of varus) parts of the growth plate of the femur or tibia. The term "outer" or "inner" part of the growth plate is conditional and implies local hypofunction of not the entire growth plate, but only a part of it.

"Normalization of growth" of lower limbs in children with axial valgus and varus deformities by eliminating the asymmetry of the axial load on the epimetaphyseal zone of the growth articular cartilage is impossible, since the functioning of the growth zones occurs until the end of the child's growth, that is, until adolescence (16-18 years). Therefore, even after corrective corticotomies and osteotomies, the problem is the development of a relapse of the deformation eliminated by surgery, which forces orthopedists to correct the deformation repeatedly, until the end of the patient's growth. Therefore, the term "normalization of lower limb growth in children" in this case is incorrect. In addition, fixation of the child's legs for 1 year with a rigid spacer and a soft lining with fixators only during daytime and nighttime sleep, "after receiving stable correction of the axial deformation of the knee joint", does not make physiological sense. Long sleep in the position of limb extension is impossible, and the functioning of the growth zones is most active during the load of the limb, that is, during the day, while walking. The supporting load of walking, even in a conventional orthopedic tutor with a knee hinge, without unloading (distraction efforts) of the area of the affected part of the growth plate, will still lead to a relapse of the existing deformation. The resulting varus, or valgus, deformations often lead to the development of flexion contractures of the knee joint. Without eliminating the contracture, it is impossible to correct the axial deformation of the limb joint. However, the proposed method does not provide for this.

Summarizing the issue of using conservative methods of treating axial deformities at the knee joint level in children, it should be noted that, according to our observations, treatment of such patients is possible using knee joint immobilization using unloading devices. Moreover, the devices should provide the ability to gradually correct valgus-varus deformity at the knee joint level, while simultaneously bringing the limb out of the vicious position to the normocorrection position, eliminating flexion contracture. That is, to treat this group of patients, an orthopedic device is needed that implements distraction efforts in two mutually perpendicular planes: to eliminate frontal deformity - valgus, varus, and to eliminate flexion contracture in the knee joint. As experience has shown, the best rate of bringing the limb out of the vicious position, and the most physiological, is a distraction rate of 1 mm per day - by analogy with the Ilizarov apparatus. At the same time, based on the law of tensile stress discovered by G.A. Ilizarov [6] even observed restoration of the contour of the missing condyle. G.A. Ilizarov himself explained the distraction rate of 1 mm per day by the fact that a capillary can grow at exactly this rate. However, since the development of deformations of the knee joint after acute hematogenous osteomyelitis is observed mainly in newborns and children of the first year of life, the use of the Ilizarov apparatus in patients of this contingent becomes impossible [7].

In 2008, an orthopedic device was created, for which we received Russian patent No. 2390319 in 2010 [8]. The results obtained from its use showed its effectiveness, especially in young children with post-osteomyelitic deformities, and even defects of the femoral condyle (external or internal), which caused these deformities.

The essence of the invention lies in a set of essential features sufficient to achieve the desired technical result, and consists in reducing the treatment time, reducing the trauma of the intervention, the absence of relapses of the deformation, while improving the anatomical and functional outcomes of treatment due to the physiological, non-traumatic, elimination of axial deformation in young children, using the Ilizarov effect [6].

The essence of the method for eliminating periarticular valgus-varus deformities at the knee joint level in children using an orthopedic device includes the application and fixation of the orthopedic device at the knee joint level in the position of the existing deformity. The deformity is eliminated using the device shown in Fig. 1. The device fastening elements, made in the form of detachable sleeves, are applied and fixed on the patient's thigh and shin so that the fixed hinge is located along the axis of movement of the patient's limb joint, in the position of the existing flexion contracture of the joint, the elimination of which is performed discretely, by manual extension of the knee joint for the detachable sleeves, rotating the plates of the fixed hinge relative to each other while loosening the threaded connection along the axis of rotation of the joint. The rate of extension correction per day is equal to a rotation by the width of one tooth, the process is continued until the contracture is eliminated, after which the valgus, or varus, deformity is eliminated, with the position of the thigh and shin brought to the anatomically correct position of the physiological axis of the limb. The distraction rate in the first 10 days is 1 mm per day on the concave side of the deformity, and is ensured by turning the nut installed in the bracket by one turn, then the distraction rate is reduced to 0.25 mm per day, which corresponds to turning the said nut by 1/4 turn. At the same time, a load is applied to the limb, for which an unloading insole made of foam plastic is inserted into the patient's shoes, the shape of which in cross-section has the form of a right triangle with a hypotenuse at the base, and in case of valgus deformity, the apex of its smaller angle faces the outer side of the foot, and in case of varus deformity - inward. As the deformation is corrected, the angle of deformation decreases, the load is increased, and the shape of the unloading insole is corrected by trimming its angle at the apex facing the side opposite to the deformation.

When pain occurs, the rate of distraction is reduced, taking a break for 2-3 days.

It is technically impossible to perform deformation correction in the presence of flexion contracture of the knee joint, since in this case, the distraction forces transmitted to the residual elements of the joint (ligamentous element, capsular, periosteum) will not correspond to the existing joint defect, which will lead to the formation of a regenerate of an irregular shape. The distraction regenerate is formed in the direction of the distraction forces exerted on the preserved paraarticular tissues.

The purpose of the correction is to restore the physiological axis of the limb in the frontal and sagittal planes, i.e. to correct the position of the femur axis to the tibia axis in the correct position (a line passing through the center of the greater trochanter, the center of the intercondylar fossa of the femur, the intercondylar eminence of the tibia and the middle of the talus). In acute hematogenous osteomyelitis, even with the destruction of bone tissue, there is preserved periosteum, capsular-ligamentous elements of the joint, which indicates that when implementing distraction, according to the law of G.A. Ilizarov, it is possible to form some kind of distraction regenerate, and at least partially eliminate the axial deformation of the segment. Therefore, it can be considered that the process of correction of deformation, and even elimination of the defect of the metaepiphysis with external structures is similar, in principle of action, to the apparatus and method of G.A. Ilizarov, so often used in the correction of deformation produced by osteotomy and the formation of a distraction regenerate of a given shape.

Distraction at a rate of 1 mm per day during the first 10 days allows to create a distraction regenerate 1 cm long, according to the standard generally accepted technique during deformation correction in the Ilizarov apparatus and osteotomy performed. This is the standard distraction rate proposed by G.A. Ilizarov, since the capillary can grow at a rate of no more than 1 mm per day. During deformation correction, a triangular distraction regenerate is formed on the concave side of the deformation. Such a size of the formed regenerate allows to determine the rate of its formation and maturation radiologically, since after osteomyelitic lesion the rate can decrease to 0.25 mm per day.

X-ray control after 10 days of distraction allows to determine the degree of "maturation" of the regenerate, and to select the optimal distraction rate on the concave side of the deformation. Since after the osteomyelitic process of any severity, the distraction regenerate of the area in question, even after osteotomy, is formed much longer, the distraction rate is reduced to 0.25 mm per day, which is 1/4 of the nut turn, since the thread in the nut-rod connection is cut with a pitch of 1 mm.

Taking into account the well-known postulate of G.A. Ilizarov's discovery about "adequacy of blood supply and load" and that "the structure, shape and volume of the musculoskeletal system are determined by the load", after eliminating the flexion contracture, they begin to apply load to the limb. In case of varus deformity, the load on the inner part of the articular cartilage prevails, in case of valgus - on the outer part. To reduce this joint compression, unloading insoles are used (Fig. 2). The installation of this insole, using the example of varus deformity, pursues the goal of unloading the inner part of the articular cartilage, with an increase in the load on its outer part.

The method is explained by illustrations:

Fig. 1 shows the external appearance of the orthopedic apparatus [8], where: 1 - detachable sleeves for each segment of the limb, equipped with splints 2 installed along the longitudinal axes of the opposite side surfaces of the sleeves 1. 3 and 4 - brackets fixed on each splint 2, in which threaded rods 5 are placed, with chamfers 6 along the entire length. In the middle part of the bracket 4, a groove 7 is formed for installing a nut 8 in it, with the possibility of rotation along the threaded rod 5. Adjacent ends of the rods 5 of the fastening elements 1 form a hinge 9 with axes 10, radially installed on two cylindrical plates 11 and 12, fastened in the center with a threaded connection 13. Plates 11 and 12 form a hinge 14 along the axis of rotation of the joint. The hinge 14 is fixed, since radially directed teeth 15 are formed on the opposite surfaces of the plates 11 and 12. A cylindrical compression spring (not shown) is installed between the plates 11 and 12, along the axis of rotation.

In this case, the axes of the hinges 9 at the adjacent ends of the rods 5 are perpendicular to the axes of these rods and the axis of the fixed hinge 14, and on the rods 5, between these hinges 9 and the mounting brackets 4, cylindrical compression springs 16 are installed.

Fig. 2 - types of insoles for valgus, or varus, deformity;

Fig. 3 - Fig. 6 are X-ray images and photographs explaining a clinical example:

Fig. 3, Fig. 4 - X-ray images of the limb of patient B. Upon admission for treatment: the absence of contours of the lateral condyle of the femur is determined, which resulted in the development of valgus deformity of the right knee joint. Flexion contracture of the right knee joint.

Fig. 5 - X-ray image after completion of treatment and correction of deformation;

Fig. 6 shows an orthopedic apparatus installed on the limb of patient V., 4 years old.

The method is carried out as follows.

In the frontal plane, in the position of the existing deformation and flexion contracture of the knee joint, the orthopedic apparatus is applied and fixed at the knee joint level. The fastening elements, in the form of detachable sleeves, are put on and fixed on the patient's thigh and shin so that the fixed hinge is located along the axis of movement of the limb joint in the position of the existing contracture. Elimination of the flexion contracture of the joint is performed by manual extension of the knee joint by the detachable sleeves, rotation of the plates of the fixed hinge relative to each other, while loosening the threaded connection along the axis of rotation of the joint. The rate of correction of extension is one tooth per day - a rotation by the width of one tooth per day. The process is continued until the contracture is completely eliminated, after which the valgus, or varus, deformity is eliminated, with the position of the thigh and shin being brought to the anatomically correct position of the biomechanical axis of the limb. The distraction rate is selected individually, and in the first 10 days it is 1 mm per day on the concave side of the deformation, and is ensured by turning the nut installed in the bracket by one turn. Then the rate is reduced to 0.25 mm per day, which corresponds to turning the said nut by 1/4 turn. At the same time, a load is applied to the limb, for which an unloading insole is inserted into the patient's shoe (Fig. 1), made of foam plastic, the shape of which in cross-section has the form of a right triangle, with a hypotenuse at the base, and with valgus deformation the apex of its smaller angle is directed outward of the foot, and with varus deformation - inward (Fig. 2). As the deformation is corrected, the angle of the deformation decreases, the load is increased, and the shape of the unloading insole is corrected by cutting its angle at the apex facing the side opposite to the deformation. In case of severe contractures, the rate of extension is increased until pain syndrome occurs, and if it develops, a break is taken for 2-3 days.

Clinical example

Patient V., 4 years old, was hospitalized with the diagnosis: Previous acute hematogenous osteomyelitis of the distal metaepiphysis of the right femur with destruction of the condyle. About a year has passed since the end of surgical treatment and closure of the last fistula. The patient did not receive orthopedic treatment. At the time of examination, the limb is in a position of flexion contracture in the knee joint at an angle of 130° and valgus deformity of 150°. Control radiography (Figs. 3, 4) reveals the absence of contours of the lateral condyle of the femur, which resulted in the development of valgus deformity of the right knee joint. Flexion contracture of the right knee joint.

In the frontal plane, in the position of the existing valgus deformity and flexion contracture of the knee joint, the patient was fitted with orthopedic device fastening elements in the form of detachable sleeves and fixed on the thigh and lower leg. In this case, the fixed hinge was positioned along the axis of movement of the limb joint in the position of the existing contracture. The rate of extension correction was one tooth per day - rotation by the width of one tooth per day. Elimination of flexion contracture of the knee joint was 5 days. The patient's parents were given instructions and recommendations for deformity correction, the distraction rate and techniques for handling the device were explained. During the first ten days, the deformity was corrected at the generally accepted rate of 1 mm per day, after which a control radiography was performed, which revealed that the selected distraction rate was excessive. The further rate was 0.25 mm per day. Simultaneously with the deformation correction and until its completion, a measured load on the limb was performed using an unloading foam insole inserted into the shoe. The insole cross-sectional shape was a right triangle with a hypotenuse at the base, the apex of the smaller angle of which was facing the outer side of the foot. The insole angle corresponded to the deformation angle determined by the radiograph. After the deformation was eliminated, the load was gradually increased until pain syndrome occurred when walking. During periodic examination of the patient, a decrease in the deformation value was determined during correction, accordingly, the insole angle was reduced. Upon achieving correction, the insole was removed. The entire correction process took 85 days, and, due to the short-term pain syndrome that developed, the correction was interrupted. The device was stabilized, and the patient wore it for 11 months in a distracted (stretched) state. The control radiography (Fig. 5) shows restoration of the contours of the outer condyle of the femur. A positive effect when using the orthopedic device was obtained in 5 patients, which allows us to recommend it for widespread use in patients with the pathology indicated.

Sources of information:

1. Zatsepin T.S. Orthopedics of childhood and adolescence. - Med-giz: M, 1956. - 320 p.

2. Marx V.O. Orthopedic diagnostics. - Minsk: Science and Technology, 1978. - 511 p.

3. Movshovich I.A. Operative orthopedics. - M.: Medicine, 1983. - 416 p.

4. Patent RU No. 2119776. Method for correction of post-traumatic deformities of the tibia in children. - B.G. Spivak, N.F. Monakhov. 1998. Bulletin No. 10 (Prototype).

5. Russian Federation Patent No. 2724387. Method for normalizing the growth of lower limbs in children with axial deformities.

6. State Register of Discoveries of the USSR. A previously unknown general biological property of tissues to respond to dosed stresses arising in them, primarily tensile stresses, by growth and regeneration caused by stimulation of biosynthesis processes in tissues (the Ilizarov effect) has been experimentally and clinically established. Author: G.A. Ilizarov Priority number and date: No. 355 of November 24, 1970. Date of registration: September 15, 1988.

7. Ilizarov G.A. Treatment of knee joint deformities according to Ilizarov with formation of a wedge-shaped regenerate: methodical recommendations / G.A. Ilizarov, V.I. Gracheva, V.N. Vasiliev. - Kurgan, 1982. - 21 p.

8. Russian Federation Patent No. 2390319 A61F 5/01, Bulletin No. 15, 2010. Orthopedic device for eliminating valgus-varus deformity at the level of the knee joint.

Claims (2)

1. A method for eliminating periarticular valgus-varus deformities at the level of the knee joint in children using an orthopedic apparatus, including the application and fixation of the orthopedic apparatus at the level of the knee joint in the position of the existing deformity, characterized in that the deformation is eliminated using the device shown in Figure 1, the fastening elements of the device, made in the form of detachable sleeves, are applied and fixed on the patient's thigh and shin so that the fixed hinge is located along the axis of movement of the joint of the patient's limb in the position of the existing flexion contracture of the joint, the elimination of which is performed discretely, by manual extension of the knee joint by the detachable sleeves, rotating the plates of the fixed hinge relative to each other while loosening the threaded connection along the axis of rotation of the joint, the rate of correction of extension per day is equal to a rotation by the width of one tooth, the process is continued until the contracture is eliminated, after which the valgus, or varus, deformity is eliminated with the position of the hip and the lower leg to the anatomically correct position of the physiological axis of the limb, the distraction rate in the first 10 days is 1 mm per day on the concave side of the deformation and is ensured by turning the nut installed in the bracket by one turn, then the distraction rate is reduced to a value of 0.25 mm per day, which corresponds to turning the said nut by 1/4 turn, simultaneously applying a load to the limb, for which an unloading insole made of foam plastic is inserted into the patient's shoes, the shape of which in cross section has the form of a right triangle with a hypotenuse at the base, and in case of valgus deformation, the apex of its smaller angle faces the outer side of the foot, and in case of varus deformation - inward, as the deformation is corrected, the angle of deformation decreases, the load is increased, and the shape of the unloading insole is corrected by cutting its angle at the apex facing the side opposite to the deformation. 2. The method according to item 1, characterized in that when pain syndrome occurs, the rate of distraction is reduced, taking a break for 2-3 days.