Multifunctional spinal osteosynthesis device.

The present invention relates to a device for osteosynthesis of the spine posteriorly with implants, which part is intended to the bone anchor in the vertebral pedicles and the other party can receive either a plate or a rod for connecting the different screw them.

Usually, implanting pedicle screws together only either by plates or by rods.

The object of the invention to provide a simple instrumentation design, allowing positioning and particularly precise and secure locking, as well as a plate of a rod, to facilitate the fixation of the spine, regardless are the anatomical conditions and deformities in kyphosis, scoliosis or kyphosis in scoliosis.

To this end, the invention relates to an osteosynthesis device of the pedicle screws in the spine of the type comprising a threaded ogive shaped tip and a threaded head, separated by a hexagonal body, the said screws being connected by a connecting element, characterized in that it comprises, furthermore, a single fastener provided with a passage hole of said threaded head on which is screwed a lock nut of the assembly fixing piece connecting element on said head, the one of the two bodies, attachment or connecting element, being formed on its lower face so as to constitute a receiving groove and locking in rotation of said hexagonal body, said jumper-shaped part being also provided with striations on its face facing the plate.

According to an application of the device, more particularly for fixing a rod, the device is characterized in that said attachment piece comprises on its upper face a groove in the bottom of which is formed said hole, whose one flank forms a shoulder and the other flank delimiting a concave surface for receiving said rod, said lock nut being provided on its underside with a frustoconical portion capable of bearing, on the one hand, against the said shoulder and, hand, against said rod and in that the underside of said fixing part comprises said receiving groove and locking the hexagonal body.

According to an application of the device particularly for fixing of a plate, the device is characterized in that said fastener is a jumper-shaped piece straddling the upper face of said plate provided with said through hole and flanked by two projections parallel side, in that said plate comprises oblong holes and is provided on its upper face, with transverse striations, and, on its lower face, said groove receiving and locking the hexagonal body.

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

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

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

The device of the invention comprises pedicle screws of known general type, composed of three parts: a Pointe1, a body 2, a head 3.

The screw is made of materials approved for surgery to be biocompatible and avoid out equipment at its penetration into the vertebral body.

The tip of the screw 1 is threaded ogival shape and preferably has a different taper between the back of the net and the top.

The head of the screw 3 has a cylindrical shape with a thread for receiving a nut (4,4 ') for locking a shaft 5 (Figure 1) or a plate 6 (Figure 3) through d a single auxiliary part (7 or 8) provided in its central portion a smooth hole 9 and threaded onto the head 3.

Nuts (4,4 ') are extended at the top by a cylindrical tubular portion 10 with slits 11 allowing a braking nuts by a slight approximation of parts 10 facing the pliers before threading the screw head 3 in the auxiliary room 7.8.

In addition, means are provided on one of the following organs: the single auxiliary part or the pedicle screws connecting element to form a housing for receiving and locking in rotation of the body 2 of the screw with respect to said element of link.

In the embodiment illustrated by Figures 1 and 2, the auxiliary piece or single intermediate 7 is interposed between a rod 12 of cylindrical section of 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 which is pierced the hole 9. One of the sidewalls of the groove 13 is straight and forms a shoulder 14 and the other flank of the groove delimits a concave surface 15 serving to house the rod 12 near the hole 9.

In this embodiment, the nuts 4 are extended at the bottom by a frustoconical portion 16 capable of coming (Figure 2) bear, on the one hand, on the edge of the shoulder 14 and, secondly, on the rod 12 in place in its housing 15 when attaching and locking all 7.12 on a screw head 3.

The part comprises, on its underside, a groove 17 (Figure 2) corresponding to the body 2 and receives the latter in the blocking in rotation.

In the embodiment of Figure 3, the single intermediate piece 8 has a general shape of a rider designed to overlap lumbosacral plate 18 of rectangular cross section, pre-curved, having from place to place slots 19 for receipt of screw heads 3.

The plate 18 comprises, on its upper surface, transverse grooves 20 and, on its underside, a groove 21 similar to the groove 13 of the part 7, and intended to receive and lock the screw body 2.

The intermediate part 8 has a central portion with a hole 9, preferably elongate for insertion amenities of the screw head 3 and flanked by two lateral projections 22 for guiding and clamping the member 8 along the face ridged upper plate 18, the face of the part 8 facing the grooves 20 being also striated correspondence.

The striations avoid moving, once the tightening of the nut 4 'made of the screw head 3 in the slot 19.

The nut 4 'is similar to that of Figures 1 and 2 except that it has no tapered portion at its base.

By altering the size of the screws (1,2,3) you can practice with the device of the invention regardless of its embodiment, vertebral fixations over the height of dorsal-lumbosacral spine.