RU2239382C2 - Intramedullary rod for performing osteosynthesis - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: device has hollow rod attachable to bone fragments with blocking screws. The rod and blocking screws are manufactured from absorbable material. Reinforcing net is attached to absorbable rod wall. The net is connected to bushing mounted on rod end. The bushing is threaded and matches the guide member allowing the rod to be introduced into medullary canal and with extractor unit allowing the reinforcing net to be removed. The bushing has threaded cork. The blocking screws are also manufactured from absorbing material and the holes for receiving them are produced in the rod just in course of operation.

EFFECT: reduced risk of traumatic complications; avoided repeated operation for removing implants.

4 cl, 5 dwg

Description

The invention relates to medicine and may find application in traumatology in the treatment of bone fractures.

There is a method of bone grafting of a tubular bone by forming a longitudinal groove on one fragment, introducing a graft into the marrow channel through the formed groove and turning it, in which a graft of rectangular shape is used, the groove is made wider than the thickness of the graft in the bone marrow channel of the opposing fragment form a channel tapering inward, and the graft is rotated relative to the groove width (see RF patent No. 2063717 according to class A 61 B 17/56, published on July 20, 1996, bull. No. 20).

The disadvantage of this method is the need to perform a longitudinal groove on one of the fragments, which complicates the healing.

Closest to the proposed invention (prototype) is a method for bone osteosynthesis of a tibial fracture in the absence of rotational displacements and a device for bone osteosynthesis (RF patent No. 2093094 according to class A 61 B 17/56, publ. 20.10.97, Bull. No. 29). The method of bone osteosynthesis of a tibial fracture in the absence of rotational displacement involves matching fragments, applying a plate to the fracture zone and fixing it with screws, screws are inserted through the skin notches above the skin, and the fragments are fixed with a plate with a longitudinal groove open from the sharpening side drawn into the fracture zone through a transverse incision of soft tissues with a width corresponding to the width of the plate proximal to the extreme of the screws. The device for bone osteosynthesis contains a plate with screw holes, one end of which is obtuse and the other has a point, while the device is equipped with a holder with a guide rod and a fastening element for the obtuse end of the plate, and the hole for the screws in the plate is made in the form of a longitudinal groove open from the point of the plate.

A disadvantage of the known method and device is that the metal plate and screws after bone fusion must be removed, which requires a second operation. In addition, the known invention is applicable only for fractures of the tibia.

The aim of the invention is to reduce the morbidity of osteosynthesis operations for various fractures of long tubular bones.

This goal is achieved by the fact that for bonding bone fragments an intramedullary rod is used, which is a hollow rod made of absorbable material, in the wall of which there is a reinforcing metal mesh attached to the sleeve installed on the end of the rod, and the sleeve is threaded under the guide for introducing the intramedullary rod into the marrow canal and under the extractor to remove the reinforcing mesh. The intramedullary shaft and screws can also be made of absorbable material of the Ethipin or Biofix brand. The reinforcing mesh is made of thin stainless wire or titanium. The sleeve is equipped with a screw plug. The holes for the locking screws are made in the rod directly during the operation.

The invention is illustrated by drawings, in which Fig. 1 shows a general view of the intramedullary nail, in Fig. 2 is a sectional view of the nail, Fig. 3 is a view of a bone with an intramedullary nail inserted, and Fig. 4 shows the introduction of an intramedullary nail into the marrow canal, figure 5 - removal of the reinforcing mesh after completion of the osteosynthesis process.

The intramedullary rod 1 (Fig. 1) is a hollow rod of absorbable material, in the wall of which, to increase the strength of the implant, a reinforcing mesh 2 (Fig. 2) is made of thin metal wire, which is fixed at the base of the rod to the metal threaded sleeve 3, and the end the rod after it is inserted into the bone is closed with a screw plug 4 with a groove 5 for a screwdriver. To bone fragments 6 and 7 (figure 3), the intramedullary shaft 1 is fixed with screws 8, which are also made of absorbable material. The introduction of the intramedullary rod 1 into the bone marrow canal is performed during the operation (Fig. 4) using a hammer 9, and the removal of the reinforcing mesh 2 (Fig. 5) is performed using the extractor 10 and the clamp 11.

The proposed intramedullary rod is used for osteosynthesis as follows. In the presence of medical indicators, i.e. in cases where significant forces from the ligaments and tendons do not act on bone fragments, use intramedullary rods of this design. To do this, in the bone fragments 6 and 7, the bone marrow canal is inserted to introduce the intramedullary rod 1. After this, an internal metal guide (not shown) is inserted into the intramedullary rod through the threaded sleeve 3, and the latter is inserted into the canal inside the bone using a hammer 9 After the insertion of the rod 1 into the medullary canal, the metal guide is removed from the rod, and a resorbable implant of the appropriate size is inserted instead. The metal sleeve 3 after the completion of osteosynthesis is closed by a threaded plug 4 in order to prevent its overgrowth with bone marrow. To fix fragments 6 and 7 to the intramedullary shaft 1, blocking absorbable screws are introduced 8. The screws are inserted at two levels (through the central and peripheral fragments of the damaged bone) after preliminary drilling of the bone and the implant directly during the operation. The reinforced metal mesh 2, made of thin metal wire or titanium, is removed after the fracture is consolidated (fused) and the implant is resorbed by successively unscrewing the plug 4 with a screwdriver, attaching the extractor 10 to the metal sleeve 3 and pulling it out of the medullary canal using clamp 11 .

Using the proposed invention allows the patient to perform only one operation - osteosynthesis and to eliminate the need for reoperation in order to remove the implant. The proposed intramedullary rod resolves within 18-24 months, the tensile, fracture and bending strength of the rod is increased to the required values due to the use of a reinforced metal mesh. You do not need to use an x-ray machine to insert the locking screws. Resorbable material implants can also be used for osteosynthesis of apical fragments and fragments of the spongy bone that are not exposed to stress.

Claims (4)

1. An intramedullary shaft for osteosynthesis, including a hollow shaft that is attached to bone fragments by means of locking screws, characterized in that the shaft and locking screws are made of absorbable material, and a reinforcing mesh is made in the wall of the shaft, which is attached to a sleeve mounted on the end of the shaft . 2. The intramedullary rod according to claim 1, characterized in that the sleeve is threaded under the guide for introducing the rod into the marrow canal and under the extractor to remove the reinforcing mesh. 3. The intramedullary shaft according to claim 1, characterized in that the sleeve is provided with a threaded plug. 4. The intramedullary rod according to claim 1, characterized in that the holes for the locking screws are made in the rod directly during the operation.

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