Compensating Plates For Bone Fractures

Abstract

Single or double plates are provided for application across the fracture site of fractured bones and wherein the single or double plates are constructed to allow for compressional and tensional forces acting on the fractured bone. When a single plate is used it is rigidly secured at one end on one side of the fracture site and at the other end by means of elongated apertures for fastening the plate on the other side of the fracture site while allowing for relative movement of the bone pieces and fragments and providing for locking the bone fragments in increasingly closer relationship as healing occurs. When two plates are used they operate in the same general functional manner, but the lower plate is provided with elongated openings on one side of the fracture site and the upper plate is provided with elongated openings on the other side of the fracture site and one plate, preferably the lower plate, is provided with a serrated jaw for the reception of a serrated tongue of the other plate which is bent into the same plane. The double plate arrangement may have one of the plates channelled for the slidable reception of the other plate. Use of the plates aids and promotes knitting of the bone fragments and enables the patients to be rapidly ambulatory.

Description

The present invention relates to compensating plate means for application to fractured bones across the fracture site and may take the form of either a single plate or a pair of overlying plates. The compensating plate means interlocks to hold the fractured bones in increasingly closer relationship as knitting occurs and provides support so as to make the patient ambulatory almost immediately. The present invention is an improvement upon the compensating plate means described and claimed in my co-pending application Ser. No. 651,754, filed July 7, 1967 now U.S. Pat. No. 3,547,114.

In the accompanying drawing

FIG. 1 is a fragmentary perspective view of a fractured bone and the compensating plate means to be applied thereto in accordance with one form of the invention;

FIG. 2 is a view generally similar to FIG. 1, but wherein the compensating plate means have been applied to the fractured bone, the compensating plate means being shown in section;

FIG. 3 is a fragmentary sectional view on an enlarged scale of the interlocking portion of the plate;

FIG. 4 is a view of a modified form of the invention wherein two overlying plates are used, one of which has a serrated jaw and the other of which has a serrated tongue fitting therewithin;

FIG. 5 is a sectional view through the compensating plate means of FIG. 4 at a 90.degree. angle thereto;

FIG. 6 is a fragmentary elevational view on an enlarged scale of the interlocking tongue and jaw portions of the plates of FIGS. 4 and 5; and

FIGS. 7, 8 and 9 are enlarged perspective views of the same type of overlying compensating plate means of FIGS. 4 to 6, but which represent a preferred mode of and the best known mode of carrying out the invention and wherein one of the plates is channelled for the slidable reception of the other plate.

Referring to the form of the invention illustrated in FIGS. 1 to 3, the numeral 10 represents parts of a fractured bone with the fracture site designated by the numeral 11, it being understood that the fracture is of known character in that it consists generally of adjacent and aligned ends of the bone together with many small and irregularly shaped pieces and particles. As rapidly as possible after fracture of the bone 10 and the alignment of the two portions the rigid plate 12 is applied across the fracture site 11, the plate 12 being made of any usual or acceptable metallic or non-metallic material such as stainless steel or a synthetic plastic. Plate 12 is provided with any desired number of countersunk apertures such as the two designated at 13, through which pass screws or other fastening instrumentalities 14 into the bone 10 on one side of the fracture site 11, as for example is indicated by the holes or recesses 15 in the bone. Plate 12 is provided with a countersunk elongated aperture 16, the countersink of which is serrated at 17 and all within a rectangular recess 18 and which, when the plate is applied to the bone, overlies at least in part the fracture site 11 and a polygonal nut 19 is provided with oppositely directed serrations 20 adapted to interlock with the serrations 17 and to move notch-by-notch within the rectangular recess 18 to allow or compensate for increasingly closer positioning of the contiguous ends of the fractured bone and the absorption or assimilation of the small bone particles or fragments particularly under the compressional forces resulting from the patient placing weight on the bone during ambulatory movements. The polygonal nut 19 has a central countersunk opening 21 through which the screw 22 passes into the bone on the other side of the fracture site as indicated at 23. One or more additional countersunk elongated openings 24 may be provided in plate 12 as shown and it is understood that a screw 25 passes therethrough into the bone as indicated at 26. The number of such additional elongated openings depends upon the particular bone involved and the size of the plate 12 which is selected for use, it being understood that the plates come in a variety of lengths and thicknesses so that the surgeon or technician can select the best plate for a given patient. It will be seen that plate 12 not only ensures the maintenance of alignment of the bone 10 on either side of the fracture site, but supplies strength and rigidity and it is capable of relative movement with respect to the fractured bone as the bone heals or knits and according to whether compressional or tensional forces are acting on the bone. Compressional forces are generally present during ambulatory movements of the patient and tensional forces may be present as during traction. It is to be understood that in order to get the best and required compensatory action from the cooperating serrated portions above described, it is necessary that the screw 22 be tightened to just the right extent, i.e. it must be tightened enough so that the parts will not become disassembled and it must not be so tight that the nut 19 becomes incapable of the above described relative movement in the rectangular recess 18.

In the modified form of the invention illustrated in FIGS. 4 to 6, there are two relatively long and slender plates, 26 which is the underlying plate and 27 which is the overlying plate. One of these plates such as the underlying plate 26 is provided with a plurality of elongated countersunk apertures 28 through which the screws 29 pass into the bone on one side of the fracture site 11 and the portion of that same plate on the other side of the fracture site is provided with ordinary drilled apertures 30 of a size to receive the shank portion of the screws directly beneath their heads. The other or overlying plate 27 is oppositely constructed in that it has ordinary drilled apertures 31 over the elongated apertures 28 and registered therewith on one side of the fracture site and elongated apertures 32 similar to the elongated apertures 28 in the portion of plate 27 on the other side of the fracture site 11 and over the ordinary drilled apertures 30. The number of elongated and ordinary apertures can vary as will be appreciated. Screws 33 pass through the sets of elongated and ordinary apertures on the other side of the fracture site as will be clear from FIGS. 4 and 5 in particular. It will be appreciated that these pairs of elongated and ordinary apertures permit relative movement of the pieces of bone 10 on either side of the fracture site 11 to allow or compensate for compressional or tensional forces in the same general functional manner as already described above, but in this form of the invention the locking means is different. In this case the lower or underlying plate 26 is provided at one end with a jaw portion 34 having serrations 35 and the other or overlying plate 27 is bent near one end at 36 into the plane of plate 26 and terminates in a serrated tongue 37 whereof the serrations are opposite to those of the jaw 34 so that as the bone portions on either side of the fracture site approach more closely to one another for or during healing or knitting, each such new position can be maintained by relative movement of the serrated jaw and tongue which become fixed in progressively different positions. For some purposes this form of the invention has advantages in that it is better for longer and more slender bones or where there is less room or space for application by the physician or technician.

The form of the invention shown in FIGS. 7 to 9 and which is the preferred form of the invention is essentially the same as the form of the invention shown in FIGS. 4 to 6, the main and only substantial difference being that the upper or overlying plate 27' is channelled at 38 for the reception and relative slidable movement of the other or underlying plate 26'. It has been found that this particular structural arrangement and cooperation of parts provides the best, smoothest and most effective action and consequently represents the presently best known mode of carrying out the invention. The other parts of FIGS. 7 to 9 are the same as those already described as will be appreciated by the use of the same numerals.

Claims

What is claimed is:

1. Plate means for bone fractures comprising a pair of rigid plates having apertures through which securing means are adapted to pass into the bone on one side of the fracture site and elongated openings through which securing means are adapted to pass into the bone on the other side of the fracture site, the plates with their apertures and securing means being arranged to respond to tensional and compressional forces acting on said fractured bone and maintaining the bone fragments at the fracture site in alignment and in position for aiding healing in which there are two relatively movable overlying plates slidable longitudinally on each other and of which one plate has a laterally serrated tongue at one extremity engaged in a serrated open-ended jaw of the other plate and bent into its plane.

2. Plate means according to claim 1 in which one of the plates has its elongated openings on one extremity of the plate and the other plate has its elongated openings on the opposite extremity of the plate.

3. Plate means according to claim 1 in which one of the plates is channelled for the reception therein of the other plate.