RU2284784C1 - Device for setting and fixing fractured bone fragments - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: device has immersible fork-shaped curved part to ½ of bone diameter having teeth on internal surface. The immersible part is rigidly attached to shank portion threaded all over its length, longitudinal through canal and slit on the external end. Wire introduced into the longitudinal canal is brought through fractured bone fragment. The external wire end is fixed in shank slit by means of two nuts. Middle part of the shank is attached to external support member of transosseous apparatus movable (to make splinter setting) and stable fixation next to it (set splinter stabilization).

EFFECT: enhanced effectiveness of reposition in three planes; reduced risk of traumatic and infectious complications.

8 dwg

Description

The present invention relates to medicine, namely to traumatology and orthopedics, and can be used for reposition and fixation of bone fragments in external fixation devices.

A known method of reposition of bone fragments using a device based on cantilever spokes with thrust pads [Sysenko Yu.M. and others. Certificate No. 7302 for a utility model of the Russian Federation, MKI 6 A 61 V 17/56]. This method has the following disadvantages:

1. The restriction to the use of the method in the presence of the main vessels and nerves in the projection, in which it is necessary to reposition the knitting needle (s), for example, when the bone fragment is localized on the inner surface of the middle third of the shoulder, thigh, etc .;

2. If there is a large volume of soft tissues on the side of the bone fragment (posterior surface of the thigh, shoulder, etc.), then holding through it a repairing needle (spoke) sharply increases the risk of eruption of soft tissues with the occurrence of pain, restriction of movements in joints, the occurrence of inflammatory complications;

3. If the bone fragment is located inside the interosseous space (forearm, lower leg), then it is not possible to use this device;

4. The need to drill a bone fragment for carrying the spokes through it increases the invasiveness of the intervention and poses a threat to the development of “spoke” osteomyelitis.

There is a method for reposition of bone fragments using hook-shaped rods pivotally fixed to the external supports of the transosseous apparatus [Barabash A.P. RF patent No. 2068241]. The disadvantages of using this device are:

1. The use of the known hook-shaped fixative is possible only if its tubular structure is preserved in the bone fragment, i.e. there is no defect in any of the cortical plates. Thus, the reposition of the marginal bone fragment by the specified device is impossible;

2. The inability to use in the presence of the main vessels and nerves in the projection, in which it is necessary to enter the rod-hook;

3. The need to form holes for the introduction of the rod-hook increases the morbidity of manipulation;

4. The introduction of a hook into the bone with a bend greater than 1/3 of the circumference is technically difficult, especially in places with a large volume of soft tissue.

Closest to the proposed one is a method for reposition and fixation of bone fragments using a device in the form of a hook-like curved rod pivotally attached to the support of the transosseous apparatus, having a bend not exceeding 1/2 of the bone diameter, equipped with pointed teeth on a concave surface, pivotally fixed to external supports transosseous apparatus [Solomin L.H. and other RF Patent No. 2233640]. The main disadvantage of using this device is the inability to reposition bone fragments along and across the anatomical axis of the bone, rotational displacements (i.e., in six standard degrees of freedom), insufficiently rigid fixation of the bone fragment.

The proposed device is deprived of these drawbacks, which provides an effective reposition of bone fragments in three planes (six degrees of freedom of movement) with minimal invasiveness of the intervention, eliminating the risk of damage to the main vessels and nerves, and reducing the likelihood of infectious complications.

A positive effect is achieved due to the fact that the device consists of a submersible fork-shaped curved part and provided with teeth along the inner surface, which is rigidly fixed to the second part, the shank, which ensures the device is connected to the support of the transosseous device. In this case, the shank along its entire length is provided with an external thread, a longitudinal through channel, and also a slot at the outer end. The needle introduced into the longitudinal channel is drawn through a bone fragment; the outer end of the knitting needle is bent into the slots and rigidly fixed to the shank with two nuts. The middle third of the shank is attached to the external support of the transosseous apparatus with the possibility of its movement using a reposition unit (for reposition of a fragment) and subsequent stable fixation (respectively, for fixing a fragment in a repaired state).

The design of the device for reposition of bone fragments and the principle of its operation are explained by the drawings: FIG. 1 is a side view of the device, FIG. 2 is a direct view of the device. In figures 3, 4, 5, 6, 7 and 8 presents the scheme of reposition and fixation of the marginal bone fragment using the developed device.

A flat arcuate bend with pointed protrusions on the concave side is made with the aim of better adaptation and fixation of the bone and eliminates the appearance of pressure sores.

The arcuate bending of the device, occupying up to 1/2 of the bone diameter, does not cause difficulties when introducing the device to the site of bone damage, and also provides the necessary stability of the bone fragment, which optimizes reposition and its subsequent fixation.

The longitudinal channel in the shank allows you to draw a spoke through it.

The external thread of the shank is necessary for fixing it in the support of the transosseous apparatus, the possibility of dosed movement in the transverse plane using two nuts (Fig.6 and 7).

Holding the spokes provides fixation of the fragment to the device, which was deprived of the prototype. This makes it possible to reposition the bone fragment not in one plane (horizontal), as in the prototype, but in three.

The slot at the end of the shank is designed to fix the needle, thereby eliminating the possibility of its migration, increasing the stability of the bone-metal block.

The reposition unit (Figs. 3, 4, 5) is a rod (1) pivotally fixed at one end to the external support of the apparatus (2). The other end of this rod is fixed to the distal (outer) third of the hook rod (3). Depending on the location of the node (2), traction (Fig. 4) or pushing (Fig. 5) of the device is carried out. The place of articulation of the hook rod to the external support of the apparatus is the center of the redistribution of power loads from the traction device to the bone fragment. This ensures the approximation of a bone fragment in the plane of the bone wound.

Figure 3 shows the possibility of moving the fragment in the frontal plane. The vertical movement of the cannulated device for reposition and fixation of bone fragments (and with it the bone fragment) is possible due to the vertical movement of the bracket, which is connected to the shank, in the support hole of the device, and due to lowering (or raising) the support of the device with a fixed on her device.

6 and 7 show the possibility of reposition of a bone fragment in a horizontal plane.

In addition, the device allows you to eliminate the rotational displacement of the fragment (Fig).

The main indications for using the proposed device is the need for reposition of the marginal bone fragment, in the projection of which (from the side of the external cortical plate) there are the main vessels and nerves and (or) there is a large volume of soft tissues, as well as cases of the bone fragment in the interosseous gap of the forearm, lower leg .

The specified device can also be used to reposition the main bone fragments, having an advantage over knitting needles with thrust pads or screw rods, for example, in the case of osteoporosis.

Use the proposed device as follows.

The radiograph determines the localization of the bone fragment, its size, location, the necessary direction of reposition, bone diameter, remoteness of the fragment from the annular support. Sterilize the device. On the extremities, the most preferred place for the introduction of the fixative is determined (away from the neurovascular bundle and where there are fewer soft tissues above the bone). After processing the surgical field and local anesthesia, the skin is punctured up to 3-5 mm. A curved clamp forms a channel in the soft tissues to the bone fragment. A device is inserted into the formed channel, orienting it so that the concave part with the teeth comes into contact with the external cortical plate of the bone fragment. Using a shank, press the fragment to the bone; a needle is introduced through the channel of the shank and a bone fragment is fixed with it to the device. After that, manually or by means of the reposition unit, the final reposition and fixation of the bone fragment is carried out and the device is stabilized. To exclude the migration of the needle, it is bent in the slots of the shank and fixed on both sides with nuts.

Information sources

1. Certificate No. 7302 for a utility model of the Russian Federation, MKI 6 A 61 V 1 7/56.

Device for the treatment of comminuted fractures of tubular bones / Yu.M. Sysenko, S.I. Shved, S.I. Novichkov (RF). - Position. Decision 10/14/97, publ. 08/16/98; Bull. Number 8

2. Barabash A.P. Compression distraction apparatus // RF Patent No. 2068241.

3. Solomin L.N., Kornilov N.V., Voitovich A.V., Nazarov V.A., Puseva M.E., Andrianov M.V. A device for reposition and fixation of bone fragments // RF Patent No. 2233640.

Claims (1)

A device for reposition and fixation of bone fragments in the form of a hook-like curved tooth rod up to ^1/2 _{of the} diameter of the bone and shank attached to the external support of the transosseous apparatus, characterized in that the shank is provided with a longitudinal through channel under the spoke for fixing the bone fragment, while the shank has a slot for bending knitting needles and an external thread, the external thread being made for fixing the needles with nuts and for fastening to the external support of the transosseous device with the possibility of dosed movement.

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