RU2793720C1 - Method for the treatment of ankle fractures associated with damage to the tibiofibular syndesmosis - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to traumatology and orthopedics, and can be used in the surgical treatment of ankle fractures combined with damage to the tibiofibular syndesmosis. A cancellous screw with a partial thread is inserted into the distal tibia through the formed bone tunnel in the distal fibula directed perpendicular to the plane of the tibial notch. In this case, the diameter of the tunnel in the fibula and the outer cortical of the tibia is made 0.2 mm larger than the diameter of the smooth part of the partially threaded cancellous screw used, the length of the partially threaded cancellous screw should be selected so that its threaded part is located in the tibia at a depth not less than 2 cm from its outer cortical layer. The cancellous screw is inserted until its cap touches the bone plate or the fibula while holding the foot in the position of maximum dorsiflexion.

EFFECT: method provides reduction of terms of treatment and rehabilitation of patients due to the peculiarities of the introduction of the spongy screw.

1 cl, 4 dwg, 2 ex

Description

The invention relates to the field of medicine, namely to traumatology and orthopedics, and can be used in the surgical treatment of ankle fractures, combined with damage to the tibiofibular syndesmosis.

The generally accepted method of surgical treatment of ankle fractures, accompanied by damage to the tibiofibular syndesmosis, is the connection of the tibia to each other by static or dynamic structures: spokes with thrust pads, a coupler bolt, a position screw, a biodegradable screw with a solid thread, various types of plates for the tibiofibular ligaments, etc. conducted at or above the level of the tibiofibular syndesmosis.

Dynamic methods of attachment allow mobility of the fibula relative to the tibia, which is more physiological, however, the amplitudes of the mobility they allow are poorly understood and do not always correspond to the amplitudes of physiological mobility. In this regard, they can excessively limit the amplitude of the mobility of the fibula in one direction and at the same time allow its pathological deviations in others. In addition, dynamic fixation methods are usually more laborious to perform, have insufficient fixation strength of the tibia for early active rehabilitation measures in the postoperative period, and (or) are not economically viable for widespread use.

Static methods of fixation of the tibia rigidly prevent pathological deviations of the fibula, however, at the same time, its physiological mobility in the tibiofibular syndesmosis is also blocked. The disadvantages of the static method of fixing the tibiofibular syndesmosis are:

1. blocking physiological mobility in the tibiofibular syndesmosis, which makes it necessary to comply with a number of restrictions in the rehabilitation period for the time of adequate union of all damaged elements that form the tibiofibular syndesmosis.

2. the need for a staged operation to remove the syndesmosis of the fixing implant within a relatively strictly defined period before the full functional rehabilitation of the patient, i.e. allowing him to fully load the leg and at the same time actively develop movements in the ankle joint.

After the operation with fixation of the tibiofibular syndesmosis with a position screw, a removable plaster splint is applied in the early postoperative period. The motor function of the injured ankle joint and the support function on the damaged limb segment "shin-foot" are excluded. During the period of outpatient treatment, the plaster splint is removed from the damaged segment of the limb, motor function is allowed in the damaged ankle joint.

Before resolving a full axial load on the leg without additional external immobilization, it is recommended to perform a staged removal of the position screw connecting the tibia to each other at the level of the tibiofibular syndesmosis, not earlier than 7-9 weeks after the operation. Depending on the nature of the fracture, patients leave the crutches and walk with a stick, loading the injured limb. During this period, they are allowed motor and support function on the damaged leg segment "shin-foot".

Violation of these recommendations leads to loosening and / or fracture of the position screw with loss of fixation of the tibia bones between themselves and a high risk of their secondary divergence if the loss of fixation occurs before the onset of adequate fusion of the damaged elements of the tibiofibular syndesmosis.

As a result of the patent information search, the following patents were selected.

A known method for the treatment of distal tibiofibular syndesmosis, involving the formation of channels in the distal metaphysis of the tibia and the outer malleolus, passing through the channels of the bone-tendon graft with wedging of the bone fragment in one of the channels. Osteosynthesis of a fracture of the fibula is carried out using a bone plate (RF patent No. 2187269). The disadvantage of this method is the high invasiveness of the operation and the low stability of the fixation of the lateral malleolus to the tibia.

A known method for the treatment of injuries of the tibiofibular syndesmosis, including the operation of metal osteosynthesis of the distal end of the fibula with an external plate, characterized in that for fixing a fracture of the fibula, an external plate is used, which is fixed to the distal fibula with cortical screws through its extreme holes, and through its two middle ones holes placed 2-3 cm above the ankle joint gap drill channels in the fibula at an angle of 25-30 to each other and through them two spongy tightening screws are inserted into the tibia (RF patent No. 2326612). The disadvantage of this method is the excessive limitation of the mobility of the fibula due to its fixation to the tibia with two multidirectional screws.

A known method of restoring the distal tibiofibular syndesmosis of the lower leg, including the implementation of the channel in the fibula, characterized in that through the external incision along the lateral surface of the lower leg 3.0 cm above the joint space of the ankle joint, a through hole is made in the lower third of the fibula in the transverse direction in the frontal plane , a cortical screw 3.0 cm long is screwed through the hole until it stops into the tibia with subsequent passage along its posterior surface paraossally (RF patent No. 2493794). The disadvantage of this method is the insufficient stability of the fastening of the tibiofibular syndesmosis - in fact, the screw is attached in the soft tissues behind the tibia. In the early rehabilitation period, the method requires a number of strict restrictions on the load regime and (or) on the development of movements in the ankle joint.

A known method of surgical treatment of fractures of the fibula in the lower third with damage to the tibiofibular syndesmosis, including intramedullary osteosynthesis. To do this, an intramedullary nail fixing the fragments is carried out in the direction corresponding to the longitudinal axis of the intact fibula. The rod is introduced into the distal fragment in a direct way, maximally displaced posteriorly and outward from the center of the cross section of the fibula, asymmetrically relative to the center of the section of the medullary canal of the central fragment (RF patent No. 2168317). The disadvantage of this method is that intramedullary insertion of the rod without the use of blocking elements can lead to the fact that in the process of bone tissue resorption, the medullary canal will expand, and the rod will begin to displace in the bone, i.e. migrate. In this case, the repairing and fixing effects of its elastoelastic deformation will be lost, i.e. treatment will be ineffective.

The closest analogue to the claimed method is a method of surgical treatment of fractures of the fibula in the lower third with a rupture of the tibiofibular syndesmosis, characterized by the fact that surgical access is performed, reposition of fragments of the fibula is performed, a channel is formed in the outer malleolus of the fibula through its apex, injected into the formed channel an intramedullary nail with holes for the locking screws, holes are formed in the lateral malleolus of the fibula, located on the same axis as the holes in the lower part of the intramedullary nail, the position of the latter is fixed by introducing locking screws through the holes in it and the lateral malleolus of the fibula, in the fibula and tibia a canal is formed above the joint space in the transverse direction to ensure that the diameter of its inlet in the fibula is greater than the diameter of the formed canal, a spongy screw is inserted through the latter, it is screwed until the head stops in the intramedullary nail with the possibility of providing dynamic fixation of the tibiofibular syndesmosis. The formation of the channel in the fibula and tibia produced 4-5 cm above the joint space (RF patent No. 2461366). The disadvantage of this method is the subsequent difficulty in removing the fixators after the fracture heals, since the screw head can become overgrown with bone tissue. At the level of 4-5 cm above the articular surface, spongy bone tissue has a less dense structure than at the level of syndesmosis.

In addition, all of the above methods of fixing the tibia at the level of the tibiofibular syndesmosis within the framework of the respective methods of treatment imply a number of restrictions on the load regime and (or) on the development of movements in the ankle joint in the postoperative period.

The aim of the invention is to reduce the time of treatment of patients with fractures of the fibula, combined with damage to the tibiofibular syndesmosis, after surgical treatment.

Achieving this goal is carried out by maintaining the mobility of the fibula relative to the tibial notch in the tibia in the created system of connection of the tibia during surgery in patients with injuries of the ankle joint, accompanied by damage to the tibiofibular syndesmosis, while the limits of the amplitudes of mobility between the tibia are almost identical to the physiological ones. This allows you to restore both the support and motor function of the damaged segment of the limb "shin-foot" simultaneously and almost immediately after the surgical intervention.

This goal is achieved through the use of a method for the treatment of ankle fractures, combined with damage to the tibiofibular syndesmosis, which consists in the use of a cancellous screw with a partial thread, characterized in that the cancellous screw with a partial thread is inserted into the distal tibia, through the formed bone tunnel in in the distal part of the fibula, the direction of which is perpendicular to the plane of the tibiofibular notch, while the diameter of the tunnel in the fibula and the outer cortical of the tibia is made 0.2 mm larger than the diameter of the smooth part of the partially threaded cancellous screw used, the length of the partially threaded cancellous screw should be selected in this way so that its threaded part is located in the tibia at a depth of at least 2 cm from its outer cortical layer, the cancellous screw is inserted until its cap is in contact with the bone plate or fibula while holding the foot in the position of maximum dorsiflexion.

An operative functional method for the treatment of ankle fractures, combined with damage to the tibiofibular syndesmosis, in which static-dynamic connection of the tibia bones at the level of the tibiofibular syndesmosis is performed using a spongy screw with a partial thread in the treatment of ankle fractures, combined with damage to the tibiofibular syndesmosis. Installation of a cancellous screw with a partial thread by the proposed method preserves the individual mobility of the fibula relative to the tibia in the tibiofibular notch and limits it only to physiological, but not pathological amplitudes. This, in turn, eliminates the restrictions on the load that are recommended for static methods of fixation of the tibiofibular syndesmosis, and relieves patients of the need for a staged operation within the regulated time frame - removal of the metal fixator fixing the syndesmosis. After the operation, (in the absence of other contraindications) no additional external fixation of the damaged limb segment "shin - foot" with a removable orthosis, plaster or polymer bandage is required. The patient is taught to walk immediately with full support on the injured limb, while developing the motor function of the injured ankle joint.

The proposed method is illustrated in the following figures:

Fig. 1 Static-dynamic connection of the tibia with a cancellous screw with a partial thread at the level of the tibiofibular syndesmosis.

A - diagram of the connection of the tibia in the frontal plane

B - diagram of the connection of the tibia in the horizontal plane

B - diagram of the connection of the tibia in the sagittal plane

D - the principle of static-dynamic connection of the tibia with a spongy screw with a partial thread

1 - cancellous screw with partial thread;

2 - fibula (2a - outer cortical layer; 2b - spongy substance; 2c - inner cortical layer);

3 - tibia (3a - outer cortical layer; 3b - spongy substance; 3c - inner cortical layer);

4 - formed channel for the screw (0.2 mm wider than the diameter of the smooth part of the screw);

5 - talus.

Fig. Fig. 2 Schematic representation of dual mobility in the static-dynamic connection of the tibia with a cancellous screw with a partial thread at the level of the tibiofibular syndesmosis with the possibility of a slight elastic deviation of the screw itself in different directions relative to its central axis, as well as the possibility of the fibula to change its position relative to the screw.

A - in the frontal plane; B - in the horizontal plane.

Designations: 1 - cancellous screw with partial thread;

2 - fibula; 3 - tibia;

4 - formed channel for the screw (0.2 mm wider than the diameter of the smooth part of the screw).

Fig. 3 An example of the proposed method No. 1 (a. - injury; c. - immediately after surgery; c. - after 6 weeks; d. - after a year and 3 months; f. - changes in the screw channel during the healing of the fracture and rehabilitation of the patient.

Fig. 4 An example of the proposed method No. 2 (a. - injury; c. - immediately after surgery; c. - after 6 weeks; d. - after a year; e. - after removal of the fixators within a year and 2 months; f. - channel changes screw during fracture healing and patient rehabilitation.

To understand the proposed operational functional method for the treatment of ankle fractures, combined with damage to the tibiofibular syndesmosis, it is necessary to know about the physiological movements of the fibula relative to the tibial notch of the tibia in the norm.

The movements of the talus during flexion and extension of the foot are accompanied by translational and rotational movements of the fibula relative to the tibial notch of the tibia. The fibula relative to the tibial notch of the tibia in the tibiofibular syndesmosis, combined with movements in the ankle joint, can move proximally, distally, rotate slightly, deviate forward and backward, outward and inward, that is, perform translational and rotational movements in 3 mutually perpendicular planes . These movements are consistent with movements in the ankle joint.

The longitudinal mobility of the fibula relative to the axis of the leg occurs within 2-2.2 mm, and with increased load - up to 4-4.5 mm. Movements in the frontal plane from 1.2 to 1.8 mm. Linear mobility in the sagittal plane up to 2 mm. During dorsiflexion of the foot, the fibula moves in a posterior-outer direction and rotates outward to 7.4°.

Such a relatively small range of motion of the fibula relative to the tibial notch of the tibia in the tibiofibular syndesmosis has individual amplitudes and features, and is essential for the correct provision of the complex function of the ankle joint. The slightest violations of this range of motion adversely affect the function of the ankle joint and subsequently can lead to certain adverse complications in the course of treatment.

The proposed operational functional method for the treatment of ankle fractures, combined with damage to the tibiofibular syndesmosis, in which the method of static-dynamic connection of the tibia in case of ankle fractures, differs from the static methods of fixing the tibiofibular syndesmosis in that it does not block the physiological mobility between the tibia bones at the level of the tibiofibular syndesmosis. And from other dynamic methods of fixation of tibiofibular syndesmosis, it is distinguished by the creation of obstacles to pathological deviations of the fibula relative to the tibiofibular notch of the tibia due to the use of a fixator, which in itself does not have internal dynamic properties.

The connection of the tibia at the level of the tibiofibular syndesmosis is carried out at the last stage of the operation after the anatomical restoration of the internal and external complexes of injuries in the ankle joint, as well as after laying and holding the fibula in its bed - the tibiofibular notch of the same name of the tibia.

A cancellous screw with a partial thread with a thread diameter of 4.0 mm is used to connect the tibia. Channel formation for a cancellous screw with a partial thread is carried out with a drill about 2.7 mm (0.2 mm wider than the diameter of the smooth part of the cancellous screw with a partial thread) within the fibula and 1.0-1.5 cm of the outer part of the tibia. The direction of passage of the cancellous screw with a partial thread should be as close as possible to the perpendicular to the relative plane of the peroneal notch, and the level of its passage in the range from 1.5 to 3-4 cm above the joint space of the ankle joint (through syndesmosis), where the spongy tissue of the tibia has denser structure. The length of the cancellous screw with a partial thread should be selected so that its threaded part is located in the depth of the tibia at a depth of at least 2-2.5 cm from its outer cortical layer. The deeper the transition point of the smooth part of the screw into the threaded one is located, the more it will be protected by the canal walls from angular overloads, while 4-cortical fixation of the tibia is not necessary (Fig. 1). When installing a cancellous screw with a partial thread, the latter is inserted no more than until the moment of its cap adjoining the extraosseous plate and (or) directly to the fibula while holding the foot in the position of maximum dorsiflexion. With this (dorsal) position of the foot in the intermalleolar space, the anterior widest part of the talus block is located, setting the necessary individual restriction on the convergence of the tibia. This allows you to save the individual functional mobility of the fibula relative to the tibial notch of the tibia and at the same time limit it from pathological abnormalities, which gives the ankle joint both functionality and stability.

The mobility between the tibia at the level of the tibiofibular syndesmosis with this method of connection is maintained due to dual mobility, which is ensured by the possibility of a slight elastic deviation of the cancellous screw with a partial thread to the sides relative to its central axis, as well as the ability of the fibula to change its position relative to the cancellous screw with a partial thread due to the difference in the diameters of its smooth part and the channel formed for it in the fibula. (Fig. 2)

In this system of static-dynamic connection of the tibia with ankle fractures, accompanied by damage to the tibiofibular syndesmosis:

1) the fibula is glided along the cancellous screw with a partial thread within the limits between the tibia and the cap (head) of the screw;

2) slight deviations of the fibula along its vertical and frontal axes are carried out due to slight vibrations of the cancellous screw itself with a partial thread, as well as due to the difference in the thickness of its smooth part and the width of the canal in which it is located;

3) rotation of the fibula along its vertical axis is carried out due to the difference in the diameter of the smooth part of the screw and the diameter of the channel made in the fibula in which it is located, and also due to slight vibrations of the cancellous screw itself with partial thread.

At the same time, the fibula is protected from pathological deviations relative to the tibial notch of the tibia by restrictions on the mobility of the spongy screw with a partial thread by the walls of its canal.

This is followed by a gradual cone-shaped expansion of the canal walls to the required size in accordance with the individual needs of the body due to the crushing of the internal thread in the canal. Subsequently, the walls of the canal become sclerosed, which is clearly seen on the control radiographs in the long-term period (Fig. 3d, 3e, Fig. 4e, 4f.)

An example of the application of the proposed method No. 1. (Fig. 3)

Patient S-ch, 19 years old. On the street, he twisted his left foot, felt a sharp pain. Delivered to hospital. Diagnosis: "Closed suprasyndesmotic fracture of the left fibula, rupture of the tibiofibular syndesmosis with outward subluxation of the foot" (Fig. 3a.). Upon admission under local anesthesia, manual reposition was performed with the imposition of an “and”-shaped plaster splint bandage. Operation on the day of admission - osteosynthesis of a fracture of the fibula in the lower third with a compression screw and a neutralizing plate, fixation of the tibiofibular syndesmosis with a cancellous screw with a partial thread (Fig. 3c.). Healing of postoperative wounds without complications. The stitches were removed after two weeks. Activation with full load on the operated limb without additional external immobilization and additional support from the second day after the operation. Returned to work (circus acrobat) 6 weeks after surgery. Recovery of ankle function was estimated at 98 points on the AOFAS scale. Radiographs of the patient 6 weeks after surgery (Fig. 3c). Radiographs of the patient 1 year and 3 months after surgery (Fig. 3d.). In the course of fracture healing and rehabilitation of the patient, a fusiform deformity and sclerosis of the canal walls from the inserted spongy screw with a partial thread (Fig. 3f) occur, indirectly indicating the preservation of the mobility of the elements in this system of tibial bones connection at the level of tibiofibular syndesmosis. Preservation of bone density on radiographs between the turns of the screw thread indirectly indicates the preservation of fixation stability.

An example of the application of the proposed method No. 2. (Fig. 4)

Patient M-at 44 years old. On the street, he twisted his left foot, felt a sharp pain. Delivered to hospital. Diagnosis: "Closed comminuted suprasyndesmotic fracture of the fibula in the lower third, fracture of the medial malleolus and posterior edge of the tibia with displacement of fragments, rupture of the tibiofibular syndesmosis, subluxation of the foot outwards" (Fig. 4a.). Upon admission under local anesthesia, manual reposition was performed with the imposition of an “and”-shaped plaster splint bandage. Operation on the 4th day after injury - osteosynthesis of a fracture of the fibula in the lower third with compression screws and a neutralizing plate, osteosynthesis of the inner ankle with a screw and a wire, connection of the tibia to each other at the level of the tibiofibular syndesmosis with a spongy screw (malleolar) with a partial thread (Fig. 4c.) . Immobilization of the posterior plaster splint bandage for 1 day after the operation.

Healing of postoperative wounds through the stage of formation of dry marginal necrosis 2.0x0.5 cm. The sutures were removed after two weeks. Activation with full load on the operated limb without additional external immobilization and additional support from the second or third day after the operation. Six weeks after surgery, the level of functionality of the ankle joint was 90 points on the AOFAS scale. Radiographs of the patient 6 weeks after surgery (Fig. 4c.). The patient achieved full functional recovery by 5-6 months after surgery. Radiographs of the patient 1 year after surgery (Fig. 4d.). After 1 year and 2 months after the operation, the fixators were removed (Fig. 4e.). In the course of fracture healing and rehabilitation of the patient, a fusiform deformity and sclerosis of the canal walls occur from the transsyndesmospongiosus screw with a partial thread (Fig. 4f.), part of the cancellous screw with a partial thread indirectly indicates the preservation of the stability of fixation throughout the time of its installation. Thus, the proposed operational functional method for the treatment of ankle fractures, combined with damage to the tibiofibular syndesmosis, in which the connection of the tibia is carried out using a cancellous screw with a partial thread, does not block the physiological mobility between the tibia at the level of the tibiofibular syndesmosis, but at the same time quite stably protects the tibia bones from pathological discrepancies.

As a result of the operation performed by this method, the shock-absorbing role of the tibiofibular syndesmosis is preserved, the possibility of a full range of motion of the talus in the intermalleolar space is preserved, which in the early recovery period of the patient's treatment makes it possible to simultaneously develop both the supporting and motor functions of the damaged limb segment "shin-foot".

This is due to the fact that the tibia in the area of the tibiofibular syndesmosis are connected to each other both stably (due to the static fixator) and functionally (due to the dynamic connection).

The proposed surgical functional method for the treatment of ankle fractures, combined with damage to the tibiofibular syndesmosis, creates favorable conditions for the earliest possible functional rehabilitation of patients, with simultaneous early recovery of both supporting and motor functions of the injured ankle joint, and their most rapid return to normal life. In addition, the proposed method allows patients to avoid a staged operation to remove the trans-syndesmosis screw in a strictly regulated time frame.

Its use can significantly reduce the treatment time for patients with ankle fractures associated with damage to the tibiofibular syndesmosis, as well as the number of early and late complications.

The offer is intended for surgical treatment of ankle fractures in trauma and orthopedic clinics.

Claims (1)

A method for the treatment of ankle fractures associated with damage to the tibiofibular syndesmosis, which consists in the use of a cancellous screw with a partial thread, characterized in that the cancellous screw with a partial thread is inserted into the distal tibia through the formed bone tunnel in the distal fibula, the direction of which perpendicular to the plane of the tibiofibular notch, while the diameter of the tunnel in the fibula and the outer cortical of the tibia is made 0.2 mm larger than the diameter of the smooth part of the partially threaded cancellous screw used, the length of the partially threaded cancellous screw should be selected so that its threaded part is located in of the tibia at a depth of at least 2 cm from its outer cortical layer, the cancellous screw is inserted until its cap is attached to the extraosseous plate or to the fibula while holding the foot in the position of maximum dorsiflexion.

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