FR2466977A1 - Bone fracture mending plate - is trough shaped and curved to match inner condyle at lower end of humerus - Google Patents

Abstract

The plate (3) for mending bone fractures, is partic. designed for the enlarged epitrochlea (11) at the lower end of the humerus. This plate is trough shaped, and is thinner than previously used flat plates. The bottom end is spoon shaped, to match the shape of the bone end. It has a straight portion at the other end with holes for securing screws. This is followed by a sloping part with an elongated hole (9) for an angled screw (10). There are three further holes (5,6) through the remainder for three more screws (7).

Description

Fractures of the humeral palette are serious due to changes in the profile of the articular surfaces that they cause. The prognosis is burdened with the risk of pain, stiffness, and discomfort in everyday life.

 The aim of surgery is to reduce displacement, and to securely maintain the various fora entes in order to allow early rehabilitation. For this, we first used pins, bolts, and screws; more recently, surgeons have used more rigid plate mountings, either posterior5 or external.

The advantages of the external plates are manifold 4 they do not risk creating an immediate annoyance when they are placed or at a distance on the ulnar nerve which circulates at the postero-internal distortion of the pallet. mechanically solid fixtures since they are less stressed than the rear plates in the flexion-extension movements of the elbow
However, these plates of the prior art, and in particular the bent plates applied to the projecting outer edge of the humeral palette (lower extremity of the humerus) have serious drawbacks.
- These plates are thick and obtained by deformation of a flat stainless steel section of several millimeters thick, which involves 1 arrangement of large holes for the passage of screws up to 50 millimeters 9 this causes damage when these screws are in place. The thickness of these external plates is required by the need for rigidity of the flat part which constitutes them, which is bent and deformed in its lower part to follow and overlap the profile of the anterior offset of the epiphysis. bulky, does not respect the adjacent muscles because of its protruding edges and risks not being tolerated very well.

- The positioning of these plates is difficult because we must fix a metal flat not on an oblate bone but on a bone are you, hence unstable tilting. Setting up is therefore difficult and immobilization of the plate on the humeral pallet only takes place after introduction and tightening of the screw. epiphyseal
- The holes made in the plate for the passage of the screws are large, corme already said and widely spaced so as not to weaken the metal flat. Under these conditions the lower part of the plate corresponding to the application on the epicondyle is pierced with only one hole, which, implying the use of a single screw, obviously does not allow to ensure a mounting of several screws in "triangulation" important factor of the solidity of the osteosynthesis.

The present invention relates to an improved plate of the aforementioned type.

It aims to remedy the aforementioned drawbacks.

 The surprising and not obvious aspect of the invention resides in the fact that we have succeeded in obtaining a plate of great rigidity, leading to osteosynthesis of great resistance, while using screws of smaller dimension than 'previously, but in greater number, allowing mounting of the triangular screws in the lower part of the humeral palette, and this, unlike the plates already known, from a metal flat noticeably thinner than the flat used previously . In other words, we obtain much better and safer results than before despite the a priori use of a metal piece originally less resistant. In addition, due to the absence of protruding edges, and serious to its low in filling thickness, this new plate is perfectly well tolerated by the adjacent muscles.

This was therefore the problem not obvious but solved according to the invention of the applicant.

 The external plate according to the invention is essentially characterized by the fact that it is formed from a metal flat of very reduced thickness close to a millimeter, profiled in its length so as to overlap laterally with the profile of the external edge of the humeral palette, then in its lower part to the profile of the anterior offset of the epiphysis, said flat being, by any suitable means, deformed transversely so as to have a gutter-shaped section adapted precisely to be applied to the outer edge of the humeral palette, said gutter ending at its lower part in the shape of a "spoon" adapted precisely to wrap the external part of the epioendyle, said spoon being pierced with at least two holes made in a particularly curved region of the plate, allowing a convergent introduction of said screws, and therefore their mounting in triangulation.

 According to a feature of the invention, the last epiphyseal screw receiving hole made in the hollow of the "spoon" is slightly ovalized so as to allow a certain angular movement of the screw in question relative to the plate.

 According to another particularity, it is made at a certain distance from the "spoon" at least one other ovalized hole allowing the fixing of a screw converging obliquely towards the ends of the epiphyseal screws, in the region of the epitrochlea while respecting the region of the olecranon dimple.

According to yet another particularity, the upper end of the plate, in a variant, does not end in a gutter but on a flat surface allowing a posteriori modeling of the plate, and in situ, in case of need of adaptation on the middle and halfway up the humerus.

 Other features and advantages of the invention will become apparent during the description which follows, given with reference to the appended drawings given by way of nonlimiting examples.

 Figure 1 shows schematically a known external plate applied to a right humerus seen in cross-section.

FIG. 2 is a similar view showing the application under the same conditions of a gutter plate, in accordance with the invention.

 FIG. 3 represents the diagram of an osteosynthesis carried out in accordance with the invention, on the lower end of a right humerus affected with supra and inter-condylar fractures, the humerus being seen by its rear face.

Figure 4 is a perspective view showing a plate according to the invention both in its longitudinal profile and in its transverse profile.

We see in Figure 1 a cross-sectional view of a humerus1.

We see in 2 a sectional view of a plate of the prior art made from a flat shape of flat. It is easy to see the difficulties of positioning, positioning, and final fixation on the bony edge of the humerus. Finally, the projecting edges 2a and 2b of the plate 2 risk causing significant intolerance.

 By cons, the plate according to the invention seen in cross section in Figure 2 in 3 is applied perfectly on the ridge thanks to its shape in gutter.

 The thickness of the plate is considerably reduced. From 4 millimeters it is reduced to 16/10 of a millimeter.

 This reduction in thickness, and therefore in resistance of the material is offset by the fundamental change in the profile of the plate, in the form of a gutter, which has just been described.

Figure 3 shows that the gutter plate 3 is deformed more longitudinally so as to adapt well to the anterior offset of the epiphysis.

 This point is important, because in intraoperative the difficulties of positioning and maintaining the plate are considerably reduced. We can even say that we manage to reduce the fragments on the plate (and not the reverse) as it applies well along the eumerus, up to the upper region 3b.

The lower end of the gutter ends in the shape of a "spoon" 3a to wrap the outer part of the epicondyle 4.

 The "spoon" 3a is pierced with at least two holes 5 and 6 allowing the introduction of the epiphyseal screws 7 and 8.

As can be seen in Figure 4, these holes are made in a particularly curved region of the plate, which allows a convergent introduction of the screws 7 and 8 and therefore their mounting in triangulation.

 In addition, in an astonishing manner, the hole 5 is slightly ovalized so as to allow a certain angular movement of the screw 7 relative to the plate. The two converging screws 7 and 8 provide a better grip and suppress rotational movements.

The setting in the epiphyseal fragment is therefore notably modified compared to the prior art.

 The length and diameter of the screws installed has also been changed. The 50 mm screws are replaced by 36 mm screws which are sufficiently solid, and cause less damage when they are put in place.

In the types of joint fractures, represented in FIG. 3, the assemblies ensuring "triangulation" are the most stable.

This is why, in accordance with the invention, an oval-shaped orifice 9 has been created at about 4.5 centimeters from the lower end of the plate, allowing a clearance of 909. With this orifice 9, if the type of fracture requires it, it is # possible to put a long oblique screw 10 in the internal column, converging towards the ends of the screws 7 and 8 in the region of the epitrochlea 11.

There are two types of plates, right and left adapted each to each epiphysis, and three lengths 10, 14 and 16 centimeters may be provided.

 This last plate is special. It can be adapted to the morphology of the bone: the outer edge erases upwards, and gives way to a flat face. The plate thus loses at its upper end 32 its gutter appearance, and becomes flat. This modification has the merit of making it possible to model the plate in its upper part if it was necessary.

For the types of articular fractures going up high on the diaphysis, this 16 cm plate becomes essential.

It goes without saying that one can, without departing from the scope of the present invention, make any modifications to the embodiments which have just been described.

Claims (4)

 1 - Osteosynthesis material for fractures of the lower end of the humerus consisting of an external plate essentially characterized in that it is formed from a metal flat of very reduced thickness close to a millimeter, profiled in its length to overlap laterally on the profile of the external edge of the humeral palette, then in its lower part to the profile of the anterior offset of the epiphysis, said flat being, by any suitable means, deformed transversely so as to have a shaped section of gutter adapted precisely to be applied to the outer edge of the humeral palette, said gutter ending at its lower part in the shape of a "spoon" adapted precisely to wrap the outer part of the epicondyle, said spoon being pierced with at least two holes for the passage of the epiphyseal screws, these holes made in a particularly curved region of the plate allowing a convergent introduction of the say screws, and therefore their triangular mounting.  2 - Plate according to claim 1 characterized in that the last epiphyseal screw receiving hole made in the hollow of the "spoon" is slightly ovalized so as to allow a certain angular movement of the screw in question relative to the plate .  3 - Plate according to claim 2 characterized in that it is made at a certain distance from the 'spoon' as minus another ovalized hole allowing the fixing of a screw converging obliquely towards the ends of the epiphyseal screws, in the region of the epitrochlea while respecting the region of the Olecranian dimple. 4 - Plate according to claim 3 characterized in that the upper end of the plate, in a variant, does not end in gutter but on a flat surface allowing a posteriori modeling of the plate, and in situ, in case need for adaptation on the middle part and halfway up the humerus.