FR2681777A1 - Surgical nail which can be implanted in the bone - Google Patents

Abstract

Surgical nail intended to be impacted axially and with force into the bone, and more especially intended for orthodontics and/or orthopaedics. Its body (1) has a shape capable of opposing extraction and movement in the bone by lateral traction (orthodontics or orthopaedic surgery) and/or axial traction (orthopaedics for supporting a ligament in particular). For orthopaedics for supporting a ligament, its stud (4) is removed, and at least one peripheral groove (15) is preferably hollowed out in its body (1).

Description

BONE IMPLANTABLE SURGICAL NAIL
The present invention relates to a surgical nail implantable in one bone, this surgical nail being more specifically, but not exclusively, intended for use in the field of dento-facial orthopedics and in particular in the orthodontic field, and / or for use in the field of orthopedics.

 It is known in orthodontics to install in the patient's mouth an elastic traction device stretched between the teeth. This device is intended to straighten a tooth or a group of teeth by applying the tensile force on a tooth or on a group of teeth of much larger seat than the tooth or teeth to be straightened, their seat being able to be increased by systems improving their anchoring: interdental or mucosally supported systems.

 The dental movements in the bone under the effect of a force being induced by the alveolo-dental ligaments, it is observed in practice that even the tooth or the group of teeth supposed to constitute a fixed point of traction have a natural tendency to move in response to the force applied to them, despite the blocking systems that may be used.

 It would therefore be desirable to be able to anchor this elastic traction device not on one or more teeth, but on a fixed anchoring member which would be constituted by an implant previously impacted in the jaw bone.

 The FR-A-2 patent application. 647.655 / 89.07487 describes a nail implantable in one bone of the jaw and intended to be used in periodontal surgery for, for example, firmly holding against the bone a flap of flesh to be grafted. This nail is made of a bio-compatible material, and advantageously of titanium.

 Such a nail is unfortunately not thus usable in orthodontics, because it is a priori quite incapable of resisting for months the constant lateral traction which is generated by the elastic orthodontic traction device.

 In the medically very different field of orthopedics, it is known, to hold a totally or partially severed ligament against the bone, to use tripod and flat staples, somewhat similar to tripod tacks intended for wall fixing of relatively heavy sheets of paper, which are implanted in the bone by hammering and arranged so as to press this ligament firmly against this bone. This flat staple is then left permanently.

 It is however essential that the staple, once implanted or "impacted" in the bone over the ligament, cannot be extracted from it, even if only by a fraction of a millimeter, which would lead to an extremely loosening dangerous from the holding pressure that is exerted on the ligament to be resold.

 The tripod staples mentioned above do not present any positive security against this dangerous risk of partial or total axial extraction.

 The US-A-4 patent. 462.395 describes an orthopedic staple having two long branches, this staple being in the overall shape of a sugar tong. Each branch of the staple is provided with a non-return profile, which improves its opposition to axial extraction.

 These two thin branches parallel to one another, however, have a great radial flexibility, and they can consequently approach one another after impacting, which does not ultimately eliminate the risk of axial extraction.

 In addition, this kind of stapling is in essence very specific to the orthopedic area of maintaining a ligament by pressing it against the bone. It does not have the solidity of a nail with a massive body which would allow it to be used for other surgical purposes, and is in particular not, and quite the contrary, an organ capable of withstanding very strong traction. lateral exerted on his head, as should be the case for a possible orthodontic application.

 The invention aims to remedy these drawbacks. It relates for this purpose to a surgical nail implantable in one bone, in particular for orthodontic and / or orthopedic application, this nail comprising an elongated and massive body intended to be force-struck in the bone and a head intended for then protrude from the surface of this bone and comprising a support flange, and being characterized by the fact that it has shape characteristics which tend to positively oppose, once said body impacted in this bone, any lateral displacement and / or axial which would tend to be imposed on it by a respectively lateral and / or axial tensile force.

Anyway, the invention will be well understood, and its advantages and other characteristics will emerge during the following description of two nonlimiting examples of the embodiment of this surgical nail, with reference to the appended schematic drawing, in which: - Figure 1 is an exploded perspective view of a form of
preferential realization of this nail.

- Figure lA is a detail view of the body of the same nail,
showing its adaptation for orthopedic use.

- Figure 2 is a cross-sectional view of the body of the same
nail, according to II-II of Figure 1.

- Figure 3 is a partial section of this same nail, made at
level of its collar.

- Figures 4 to 6 show other possible cross-sectional shapes
for the body of that same nail.

- Figures 7 and 8 show respectively two modes
use of this nail: in orthodontics and orthopedics.

- Figures 9 and 10 show other examples of profiles which
can be given to this nail for use in
orthopedics.

- Figure it shows a mode of use in orthopedic surgery
a nail according to Figure 1.

- Figure 12 is a perspective view of another form of
realization of this nail.

- Figure 13 is a cross section, taken along XIII-XIII of
Figure 12, of the body of this last nail.

 Referring to FIGS. 1, 2 and 3, it is a surgical nail impactable in the bone, made of titanium or any other bio-compatible alloy and which, as shown in these figures, is intended for the maintenance of an elastic lateral traction member in dentofacial orthopedics and in particular in orthodontics, but which, with very little modification which can be performed a posteriori, can also be used in orthopedics to almost completely maintain a ligament or partially sectioned or to constitute fixing points for fixation in a bone for the reduction and the containment of bone fractures.

 This nail is composed of a body 1, solid and elongated, and of a head 2 which itself comprises a large flat and circular collar 3 and an axial protuberance in the form of a pin 4.

 The body 1 is intended to be impacted by force, and up to the guard, in the jaw bone, and the collar 3 serves as a stop and seat member. This seat is reinforced by three coaxial and circular ribs 5, 6, 7, which are provided on the underside 8 of the flange 3, and which also serve, for the orthopedic application which will be described below, to maintain a ligament.

 The lug 4 is intended for holding the wire or other traction member in orthodontics, and it is therefore provided with a groove 9 around which it is possible to pass this wire, as well as a transverse drilling 10 to through which this same wire can pass.

 In orthopedic application for maintaining a ligament, this lug is absent, so as not to interfere with the sliding of the tissues on the flat outer face of the collar 3. It is therefore advantageously removable by unscrewing and its lower part or end piece 12 is threaded Consequently. In addition, as will be seen below with reference to FIG. 11, the threaded part 13 can allow the fixing of fixators for the use of such a nail in orthopedic surgery.

 In addition to these three ribs 5 to 7, and in addition to a blind and tapped axial bore 13 for receiving the screwable end 12 of the lug 4, four holes 14, paramedians and parallel to the axis of the nail, are formed in the collar 3, and are intended to receive a four-pin key for the extraction of the nail by quasi-unscrewing when the orthodontic traction has ended.

 The body 1, which has a free end sufficiently pointed to allow its easy impacting, has a polygonal section with several slightly concave faces 25 (but which can be planar), here in the form of a pentagon, and is, on the other hand, twisted in the form of 'very wide pitch propeller, of the order of a quarter to three quarters of a turn over the entire length of the nail to fix ideas.

 These particular shape characteristics greatly increase lateral stability in the event of orthodontic traction.

The twisted nature of the body 1 provides appreciable support security during work in the mouth, the latter being always very delicate. The pitch of 1 propeller, being less than about a revolution, and preferably being of the order of a fraction of a revolution, over the entire length of the body 1, is wide enough not to interfere with the laying of the nail by axial impact at strength. On the other hand, this twisting allows easy extraction of the nail by unscrewing by means of the aforementioned pin wrench.

 The nail shown can have a quasi-polygonal section of another type: for example, according to the respective figures 4 to 6, a section with hexagon, with four sides, or with three sides.

 The twisted nature of this nail does not however give it the satisfactory characteristic of total opposition to the axial extraction which is highly desired in orthopedics.

This is why, for this last application of this nail, it is planned to mill in the body 1 thereof one or more peripheral grooves 15 (Figure 1A) that the bone will fill by osteogenesis after the impact of the nail ligament support.

 Note that, for this purpose, various forms of non-return profiles can be created, such as those according to FIGS. 9 (truncated cones in series 21) and 10 (scales 22) which are borrowed from the DIY field, possibly 'These are profiles which, for example having a slope directed towards the axis and towards the tip of the nail, do not in any way interfere with the axial impact by force of this nail.

 For a more economical embodiment, it is also possible, in the case of nails intended only for one orthopedic application of ligament fixation, to provide these latter nails without lug 4, and even even without the orifices 13 and 14. Note however that these latter holes 14 still allow in orthopedics to easily remove the nail by unscrewing if the impacting is not satisfactory.

 Figure 7 shows the use of this nail in orthodontics, where it is impacted in the bone 16 of the jaw, a wire 17, or other conventional elastic member of orthodontic traction, being passed through the orifice 10 or around the groove 9 of its lug 4.

 Figure 8 shows the use of this same nail in orthopedics, where it is used to press and maintain, thanks to its collar 3 and its circular ribs 5 to 7, a ligament 18 against for example 1 knee bone 19. For this In use, the lug 4 has been removed, and a peripheral groove 15 has been milled in the body 1 of this nail.

 Likewise, FIG. 11 shows the use of this same nail, if necessary provided with larger dimensions, in orthopedic surgery, for the reduction and the containment of bone fractures. In this case, 1 1 previous pin 4 is replaced by a fixator 26 which is screwed in its place in the blind hole and tapped 13. In the drawing two nails of this type are shown each impacted in a respective fraction 27.28 of the fractured bone, and a device 29 for tensioning and restraining is stretched between the two fixers 26.

 An alternative embodiment of this nail is shown in FIGS. 12 and 13.

 According to this variant, the body 1 is not twisted, but its cross section (FIG. 12) has an oblong shape 23 and in fact is very flat, with preferably a concave part 30 which, by increasing its lateral bearing surface, improves its resistance to extraction during orthodontic traction. This resistance to lateral traction is further increased here by the fact that four long protuberances constituted by small paramedian nails 20, parallel to the body 1 and the tip of which is also directed downwards, are provided on the underside 8 of the collar 3. These nails 20 are also generally capable of ensuring the maintenance of the ligament in orthopedic application, so that, as shown, the circular ribs 5 to 7 may be absent in this embodiment.

 Note that these paramedian nails 20 can be removably mounted by unscrewing on the underside 8 of the flange 3.

 It goes without saying that the invention is not limited to the embodiment which has just been described. Other forms capable of opposing the extraction of this nail by lateral and / or axial traction are possible. Instead of providing the holes 14, it is also possible to give the lug a shape, for example with a hexagon, allowing it to receive a key, or a screwdriver, for unscrewing the nail. This lug can be made integral with the collar. The body 1 may have one or more planar or concave faces without its section being quasi-polygonal; etc ...

Claims (13)

 1- Surgical nail implantable in the bone, in particular for orthodontic and / or orthopedic application, this nail comprising an elongated and solid body (1) intended to be forced into the bone (16,19) and a head ( 2) intended then to protrude from the surface of this bone and comprising a support flange (3), characterized in that it has shape characteristics (25,23,20; 15,21,22) which tend to oppose positively, once said body (1) impacted in this bone, any lateral and / or axial displacement which would tend to be imposed on it by a respectively lateral and / or axial tensile force.  2- surgical nail according to claim 1, characterized in that its body (1) has a section which has one or more planar or concave faces (25).  3- surgical nail according to claim 2, characterized in that its body has a quasi-polygonal section.  4- surgical nail according to one of claims 1 to 3, characterized in that its body has a flattened section (23) and may have concavities (30).  5- surgical nail according to one of claims 1 to 4, characterized in that the underside (8) of its flange (3) is equipped with one or more long paramedian protuberances (20) in the form of nails parallel to the body (1) and directed in the same direction, these nails (20) can be removable by unscrewing.  6- surgical nail according to claim 3, characterized in that its body (1) is twisted according to a helix whose pitch is wide enough not to prevent impacting this nail axially and force.  7- surgical nail according to claim 6, characterized in that the pitch of this helix is of the order of a fraction of a turn over the entire length of the body (1) of the nail.  8- surgical nail according to one of claims 6 or 7, characterized in that its head (2) is shaped, for example by means of orifices (14) provided in its collar (3), to receive a key allowing the extraction of this nail by unscrewing.  9- surgical nail according to one of claims 1 to 8, characterized in that the underside (8) of its flange (3) comprises one or more circular and coaxial ribs (5,6,7).  10- surgical nail according to one of claims 1 to 9, characterized in that the upper face (11) of its flange (3) is left bare in the case of orthopedic use of this nail in particular for the maintenance of 'A ligament (18), while it is contrario equipped with a lug (4) for fixing a member (17) of lateral traction in the case of orthodontic use of the same nail or a fixative (26) in the case of use in orthopedic surgery (27,28,29).  11- A surgical nail according to claim 10, characterized in that this lug (4) or this fixator (26) is removably mounted on this flange (3).  12- Surgical nail according to one of claims 1 to 11, characterized in that, in particular in the case of orthopedic use for maintaining a ligament (18), provision is made to machine one or more peripheral grooves ( 15) in the body (1) of this nail.  13- Surgical nail according to one of claims 1 to 12, characterized in that, in particular in the event of orthopedic use for the maintenance of a ligament, it is planned to then confer on its body (1) an anti- back, for example with trunks of cones (21) or scales (22), this profile being oriented so as not to oppose the axial impact by force of the nail.