Multifunctional spinal osteosynthesis device.

MULTIFUNCTIONAL SPINE DD OSTEOSYNTHESIS DEVICE

The present invention relates to a device for the osteosynthesis of the spine by the posterior route with implants, one part of which is intended for the cssous anchoring in the vertebral pedicles and the other part makes it possible to receive either a plague or a rod to connect them. different screws between them.

Usually, pedicle screws are implanted uniquely joined either by plates or by rods.

The aim of the invention is to provide instrumentation of simple design, allowing particularly precise and safe positioning and blocking, both from a plague and from a rod, with a view to facilitating the osteosynthesis of the spine. either the anatomical conditions and the deformities in kyphosis, scoliosis or kyphosis scoliosis.

To this end, the invention relates to a device for osteosynthesis of the spine with pedicle screws of the type comprising a threaded ogival tip and a threaded head, separated by a hexagonal body, said screws being connected by a connecting element, characterized in that it further comprises a single fixing piece provided with a hole for passing said threaded head on the tube is screwed a locking nut of the fixing piece assembly connecting element on said head, one of the two members, fixing part or connecting element, being shaped on its underside so as to constitute a groove for receiving and locking in rotation of said hexagonal body, said part in the form of a rider also being provided with grooves on its face opposite the beach.

MA 22018EN

According to an application of the device more particularly to the fixing of a rod, the device is characterized in that said fixing part comprises on its upper face a groove in the bottom of which said hole is formed, one of the sides of which forms a shoulder. and the other side of which delimits a concave surface for receiving said rod, said locking nut being provided on its underside with a frustoconical part capable of coming to bear, on the one hand, against said shoulder and, on the other hand, against said rod and in that the lower face of said fixing part comprises said groove for receiving and locking the hexagonal body.

According to one application of the device more particularly to the fixing of a plate, the device is characterized in that said fixing part is a part in the form of a jumper overlapping the upper face of said plate provided with said passage hole and flanked by two projections parallel sides, in that said plate has oblong holes and is provided, on its upper face, with transverse ridges, and, on its lower face, of said receiving groove and blocaqe of the hexaqonal body.

Figure 1 of the accompanying drawing is an exploded view of an embodiment of the device of the invention to the attachment of a rod.

Figure 2 is a sectional view of the device of Figure 1 assembled.

FIG. 3 is an exploded view of one embodiment of the device for fixing a plate.

The device of the invention comprises pedicle screws, of known general type, composed of three parts: a pointel, a body 2, a head 3.

The screw is constructed from materials approved for surgery in order to be bio-compatible and to avoid material breakage at the level of its penetration into the vertebral body.

The tip of the screw 1 has a threaded ogival shape and advantageously has a different taper between the bottom of the threads and their top.

The head of the screw 3 has a cylindrical shape with a thread for receiving a locking nut (4.4 ')

MA 22018FR with a rod 5 (figure 1) or a plate 6 (figure 3) via an unigue auxiliary part (7 or 8) provided in its central part with a smooth hole 9 and threaded on head 3.

The nuts (4,4 ') are extended in the upper part by a cylindrical tubular part 10 with slots 11 allowing the nuts to be braked by a slight approach of the opposite parts 10 using pliers before threading the screw head 3 in the auxiliary part 7,8.

In addition, means are provided on one of the following two members: the unigue auxiliary part or the connecting element of the pedicle screws, to constitute a housing for receiving and locking in rotation the body 2 of the screws with respect to said element. binding.

In the embodiment illustrated by Figures 1 and 2, the unigue auxiliary or intermediate part 7 is interposed between a rod 12 of cylindrical section with a diameter sufficient to withstand the stresses and forces of the spine, the smooth surface having the advantage to allow bending to obtain a certain curvature, adapting to deformations or to the anatomy of the spine.

This part 7 has, on its upper face, a central groove 13 in the bottom of the laguelle is drilled the hole 9. One of the sides of the groove 13 is straight and forms a shoulder 14 and the other side of the delimited groove. a concave surface 15 serving as a housing for the rod 12 next to the hole 9.

In this embodiment, the nuts 4 are extended in the lower part by a truncated part 16 capable of coming (FIG. 2) to bear, on the one hand, on the rim of the shoulder 14 and, on the other hand, on the rod 12 in] place in its housing 15 when fixing and locking the assembly 7,12 on a screw head 3.

The part comprises, on its lower face, a groove 17 (FIG. 2) corresponding to the body 2 and receiving the latter by blogging it in rotation.

In the embodiment of FIG. 3, the unigue intermediate piece 8 has the general shape of a rider intended to overlap a lumbosacral plague 18 of cross section.

MA 22918FR rectangular, pre-curved, comprising from place to place oblong holes 19 for receiving the screw heads 3.

The plate 18 comprises, on its upper face, transverse ridges 20 and, on its lower face, a groove 21 similar to the groove 13 of the part 7, and intended to receive and block the screw bodies 2.

The intermediate part 8 comprises a central part pierced with a hole 9, preferably oblong for ease of insertion of the screw head 3 and flanked by two lateral projections 22 for guiding and wedging the part 8 along the face. upper striated of the plate 18, the face of the part 8 facing the striations 20 also being striated in correspondence.

The ridges prevent the displacement, once the nut 4 'has been tightened, of the head of the screw 3 in the oblong hole 19.

The nut 4 'is similar to that of figures let 2 except that it does not have a frustoconical part at its base.

By modifying the size of the screws (1,2,3) it is possible to practice with the device of the invention regardless of its variant embodiment, vertebral fixations over the entire height of the dorso-lumbosacral spine.