RU2245685C2 - Device for carrying out compression osteosynthesis - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: device has compression clamp having fixing pedicle on one end manufactured from titanium nickelide possessing shape memory and superelasticity properties, intramedullary rod for setting fractured bone fragments having intraosseous and extraosseous parts. The rod is manufactured from biologically inert material and is coupled with the second end of the compression clamp. The rod-to-clamp joint is movable and allows rigid fixation of bone fragments.

EFFECT: enhanced effectiveness in selecting compression clamp position after setting bone fragments.

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Description

The invention relates to medical equipment and is intended for the surgical treatment of fractures of mainly metaepiphyseal sections of long tubular bones.

With the invention of titanium nickelide-based alloys, the technique for treating bone fractures underwent a conceptual transformation in the direction of intramedullary (intraosseous) fixation of fragments and bone compression with braces from these alloys. The task of osteosynthesis itself is all the more invariant in solving, the more complicated the fracture is in its topography and the number of comminuted fragments. Reposition of fragments, their fixation, compression with all necessary conditions for the success of the operation elevate the surgeon's work to the level of solid creativity and improvisation. Moreover, the technical means used must meet many requirements in order to contribute to success.

The prior art includes the closest analogues using alloys based on titanium nickelide and recently constituting a separate promising area of surgical traumatology and orthopedics.

A device [1] for compression osteosynthesis in fractures of tubular bones, in particular, metaepiphyseal localization, containing an intramedullary pin 2 (hereinafter referred to as the pin) and compression bracket 1 (Fig. 1) (hereinafter referred to as the bracket) is known. The pin is made in the form of a spoke of titanium and is installed when repositioning fragments inside the bone, in a specially prepared bed of the medullary canal. The function of the pin is the correct comparison of bone fragments, their connection and primary fixation. The bracket 1 has an active section of a Ω-shaped and legs at both ends to fix it in the tissue of the connected bone fragments. When installing staples for legs, a bed is prepared - holes are drilled, and the distance between them is selected in excess of its stationary value, established after compression. Compression is performed by realizing the memory effect of the form of titanium nickelide.

The device has found application in clinical practice, but its drawback is the need to drill two holes to fix the bracket, i.e. increased invasiveness, prompted to seek new solutions.

A device for compression osteosynthesis [2], made of titanium nickelide with the effects of shape memory and superelasticity, is known. The device (figure 2) contains the signs of the previous analogue, i.e. compression bracket 1 and intramedullary pin, 2 but, in contrast to it, united by rigid fastening them at the second end of the bracket. Thus, the second leg is abolished and with it the need for a separate bone bed for it. The pin is located and oriented relative to the bracket, taking into account the orientation of the intramedullary canal being prepared for it and the bone defect itself. To install the device, it is necessary to design its configuration, basic dimensions according to the data of an X-ray examination, and during the operation follow the plan, as the integrity of the structure of the device does not allow you to adjust the positioning of the bracket. The need for such correction almost always exists after exposing the fracture site and analyzing the visual examination. Thus, the disadvantage of this analogue, which is most chosen for the prototype of the proposal, is low installation variability.

The technical result of the proposed solution is to increase the variability of the installation of the device.

The specified technical result is achieved in that in a device for compression osteosynthesis containing a compression bracket with a fixing leg at one end made of titanium nickelide with shape memory and superelasticity effects, an intramedullary pin for reposition of bone fragments with intraosseous and extraosseous sections made of bioinert material and articulated with the second end of the compression bracket, the joint of the pin with the compression bracket is movable.

The significance of the distinguishing feature - the movable joint of the bracket and the pin - follows from a comparison of the composition of the necessary actions when installing devices: prototype and proposal.

After access to the injured area of the bone, the fragments are repositioned using the spatially combined insertion of a pin (if necessary, several pins) into them. Since the connection of the pin and the bracket in the prototype is rigid, the place of fixation of the bracket with its leg is prescribed, because alteration of the device during the operation is unlikely. The movable joint of the pin and staples of the proposed device provides the ability to change the place of fixation of the staple. The type of joint determines the degree of mobility. Techniques for implementing mobility are diverse, but are limited by a number of conditions: reliability, structural simplicity and compactness, anatomical conjugation, ease of action, manufacturability. The compression of the bone fragment necessary for successful osteosynthesis, determined by the stiffness of the staple fixation in the presence of a movable joint of the staple and the pin, is ensured by the elastic connection of the Ω-shaped portion of nickelidotitanium staple 1 (Fig. 1). When mounting and installing the device, a possible backlash in the connection of the bracket and the pin is “selected” also by bending the extraosseous portion of the pin.

The material of the pin can be selected from a number of modern biocompatible and mechanically strong materials, such as titanium, stainless steel, titanium nickelide, etc.

The specified technical result in the consumer plan ensures the surgeon’s efficiency, the correct choice of the optimal compression option and, as a result, the improvement of osteosynthesis.

The drawings show:

figure 1 - a device for compression osteosynthesis (analogue) with disparate bracket 1 and pin 2,

figure 2 - device for compression osteosynthesis (prototype) with articulated and rigidly fastened bracket 1 and pin 2,

figure 3 - a device for compression osteosynthesis (proposal) with a movable articulation of the bracket and pin. 1 - bracket, 2 - pin, 3 - fixing leg of the bracket, 4 - loop-shaped second end of the bracket, 5 - extra-bone section of the pin,

figure 4 - installation diagram of a device for compression osteosynthesis in fractures of metaepiphyseal sections of long tubular bones.

The efficiency of the proposed invention and the attainability of the technical result is confirmed by examples of specific implementation in the treatment of bone fractures in the trauma center of the district hospital of Surgut.

Example.

Patient E., 40 years old. Diagnosis: closed intraarticular, comminuted, impression fracture of the distal metaphysis of the tibia and the outer ankle of the left lower leg.

For surgical treatment, a device for compression osteosynthesis with a complex of features of the present invention was used. The active section of the compression bracket 1 (Fig. 3) is made in the form of an Ω-letter made of nickelidotitanium wire with a diameter of 1.2 mm of the TN-10 alloy. One end of the bracket 20 mm long is bent 90 ° from the plane of the active sections and serves as a fixing leg 3. The second end is molded in the form of a loop 4 with a diameter of 2.5 mm, covering the extraosseous section 5 of pin 2. The intramedullary pin 2 is made of titanium.

The device during the operation works as follows: under spinal anesthesia with open access, reposition of fragments and their primary fixation by incomplete insertion of pin 2 into the spatially combined intramedullary bed (Fig. 4). At a distance from the mouth of the made bed, exceeding by 8-10 mm the length of the bracket from the loop-shaped end 4 to the fixing legs 3, a hole is made - a bed for the fixing legs. In this case, the position of the hole on the bone is selected based on the configuration of the fracture and the most favorable direction of the forthcoming compression efforts. After cooling under chloethyl, the bracket is unbent to a length corresponding to the specified distance, and set, fixing with a leg and putting on a loop on the protruding (extraosseous) end of the 5th pin. Pin 2 is tightened by 1-1.5 cm, bent 60-90 ° to the side opposite to the position of the bracket, and returned to the previous depth.

Warming the staples to the patient's body temperature leads to its deformation in the direction of the initial state and compression of the bone fragments. The surgical wound is sutured.

After the operation, the leg is laid on the Beler tire. After 12 days, the stitches were removed, and the patient was discharged for outpatient treatment with the permission of dosed walking with crutches.

A series of similar successfully completed operations indicates the high efficiency of the devices, the attainability of the technical result and the promise of widespread use in surgical practice.

Sources used in compiling the description:

1. Delay Law and New Class of Materials and Jmplants in Medicine Edited by B.E. Gunther, STT, Northampton, MA 2000, pp. 167-168.

Claims (1)

A device for compression osteosynthesis comprising a compression bracket with a fixing leg at one end made of titanium nickelide with a shape memory effect and superelasticity, an intramedullation pin for reposition of bone fragments with intraosseous and extraosseous sections made of bioenergy material and articulated with the second end of the compression brace characterized in that the joint of the intramedullary pin with the compression bracket is movable with the possibility of rigid fixation of bone fragments.

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