Field of the invention

The present invention relates to a surgical kit for vertebral stabilization, including an intersomatic designed to be inserted between two contiguous vertebrae so as to space them apart and thus keep them at a mutual distance such to restore the intervertebral space, and an operating instrument for the surgical insertion of the intersomatic cage.

State of the prior art

Intersomatic cages typically comprise a body provided with a nose protruding from the front end thereof so as to be introduced between two contiguous vertebrae and space them apart so as to allow the insertion of the cage, and external formations for anchoring to the vertebrae. The rear end of the body of the cage is provided with a recess for coupling with an operating instrument for inserting the cage into the intervertebral space. The operating instrument typically consists of a stem having a handle at one end and shaped so as to be coupled with the recess of the intersomatic cage at the other end.

State of the prior art

Document EP2231074 describes a surgical kit of the type defined above, as well as the method of use thereof. In summary, the body of the intersomatic cage, whose rear recess is coupled with the stem of the operating instrument, is introduced with the nose thereof between the two vertebrae to be stabilized. Then, by acting on the handle, the stem is alternately rotated in opposite directions and simultaneously pushed axially so as to dilate the intervertebral space and wedge between the two vertebrae. The cage, thus stably fitted by means of the anchoring formations with which it is provided, is lastly released, hence disengaging the operating stem - thus removing it - from the rear recess thereof.

The intersomatic cage insertion operation is relatively complicated, in particular due to the fact that once it has been inserted into the back of the patient, it is no longer visible to the surgeon, who is therefore unable to verify the angular position thereof so as to be able to correctly calibrate both the direction and the extent of the alternate insertion rotations.

Summary of the invention

The object of the present invention is to solve the aforementioned problem in a simple but at the same time fully effective manner.

According to the invention, this object is achieved due to a surgical kit of the type defined above, whose distinctive characteristic lies in the fact that an indicator member representing the shape and angular position of the intersomatic cage is arranged on the stem of the operating instrument, at a position visible when inserting the intersomatic cage coupled to the operating instrument.

Thanks to this solution idea, during the insertion operation the surgeon is able to constantly know the angular position of the intersomatic cage so as to be able to accurately evaluate both the direction and the extent of the alternate angular displacements required for the correct insertion of the cage into the intervertebral space.

According to a preferred embodiment of the invention, the indicator member consists of a body having the same shape, in larger scale, as the body of the cage and fixed on the stem in the same angular position as the cage coupled to the stem.

In a variant of the invention, a support carrying plurality of bodies angularly offset with respect to one another and having shapes corresponding to those of intersomatic cages designed to be coupled to the operating instrument is rotatably fixed to the stem. The support is designed to be locked on the stem in the position in which the body corresponding to the intersomatic cage coupled to the operating instrument is angularly aligned with such intersomatic cage.

In this manner, the operating instrument of the surgical kit according to the invention can be used with several intersomatic cages of different shapes and sizes.

Brief description of the drawings

The invention will now be described in detail, purely by way of non-limiting example, with reference to the attached drawings, wherein:

- figure 1 is a schematic perspective view of a surgical kit according to a first embodiment of the invention, figures 2, 3 and 4 are respectively plan, elevational and longitudinal section views of the kit of figure 1, figure 5 is a front perspective view of a variant of the operating instrument of the surgical kit according to the invention,

- figures 6, 7, 8 and 9 are lateral elevational views of the operating instrument of figure 5 rotated by 90° with respect to each other, and

- figure 10 is a dorsal perspective view of he operating instrument of figure 5.

Detailed description of the invention Referring initially to figures 1 to 4, the surgical kit according to a first embodiment of the invention essentially comprises an intersomatic cage 1 and an operating instrument 2 for inserting the intersomatic cage 1 into an intervertebral space.

The intersomatic cage 1 is of the per se generally known type and it includes a body with two opposite faces provided with anchoring formations 3, 4, a nose 5 protruding from the front end thereof and designed to be inserted between two contiguous vertebrae to space them apart during the surgical insertion of the cage 1, and a rear recess 6, better visible in figure 4 and configured for the coupling thereof with the operating instrument 2.

The operating instrument 2 consists of an elongated tubular stem 7 rotatable within which is a longitudinal rod 8 which is rotatably coupled to a handle 9 at one end and protrudes from the tubular stem 7 at the opposite end so as be able to engage in the recess 6 of the intersomatic cage 1, as shown in figure 4.

According to the distinctive characteristic of the invention, the stem 7 is configured to reproduce the shape and angular position of the intersomatic cage 1 coupled thereto. To this end, an indicator member 10, having the same shape, in larger scale, as that of the intersomatic cage 1, is fixed on the stem 7 at an angular position identical to that of the intersomatic cage torsionally coupled to the rod 8. The axial position of the indicator member 10 is sufficiently proximal to the operating handle 9 so as to be constantly visible to the surgeon during the intersomatic cage insertion operations. This visibility allows the surgeon to constantly evaluate the angular position of the cage 1 and to calibrate both the direction and the extent of the alternate rotations imparted to the cage 1, through the operating handle 9, until it is completely inserted into the intervertebral space.

The variant of the invention shown in figures 5 to 10 differs from the embodiment described above only by virtue of the fact that the indicator member, indicated with 10', consists of a support rotatably fixed to the stem 7 and carrying a plurality of bodies 11 angularly offset from each other and having shapes corresponding to those of different intersomatic cages designed to be fixed to the operating instrument 2. In the case of the illustrated example, there are three bodies 11, angularly offset by 120°, but this number could be different.

The support 10' can be locked angularly with respect to the stem 7, for example by means of a vice clamp - not illustrated - or similar equivalent systems known to the man skilled in the art, so as to angularly align the body 11 corresponding to the intersomatic cage selected for the surgical insertion operation, with such an intersomatic cage.

This solution obviously has the advantage of allowing to use the same operating instrument 2 with a plurality of different intersomatic cages 1.

Obviously, the construction details and the embodiments may widely vary with respect to what has been described and illustrated, without departing from the scope of protection of the present invention as defined in the claims that follow.