The present application claims priority from European Patent Application No. 12150401.3 filed Jan. 6, 2012, the disclosure of which is hereby incorporated herein by reference.
The present invention relates to soft tissue protector and drill guide for guiding elements, especially drill bits and implants of an implantation kit during a surgical intervention, comprising a soft tissue protector main body having a gripping portion, wherein the drill guide has an upper and a lower opening along its longitudinal axis with a through going cavity for receiving the element to be guided, and a lower object contact surface to be positioned on an object on or into which said element is to be guided, wherein the diameter of the through going cavity can be varied.
Drilling and positioning implants in bones require protection of the surrounding soft tissues. In the prior art this is achieved through hollow cylindrical metallic parts that prevent contact between the instrument or implant and the surrounding soft tissues. These same tools are produced in different diameters in order to accommodate for different drill bits and implants diameters.
The soft tissue protector can be also used to roughly guide the surgeon in achieving determined alignments between implants. Several of these soft tissue protectors can be joined through a metallic connector and help the surgeon drilling concentric holes and maximizing the implant grip in the bone.
The use of implants having many different diameters requires the surgical sets to be equipped with a considerable number of parts. These are the drills necessary to perform adequate holes and the chucks necessary to join the drill bits to the drill, different trocars and sleeves. For using 3, 4, 5 and 6 millimetre pins, e.g. twelve different parts can be necessary. A large number of parts require the surgeon and the assistants to pay additional attention in selecting the proper equipment. Furthermore, so many parts result in a heavier and larger instruments tray.
A drill guide and soft tissue protector is known from U.S. Patent Application Publication No. 2010/0232897. This drill guide has a main body with a flat base and an aperture for assisting the movement of the drill bit. Interchangeable drilling heads adapted to guide drill bits of different diameters are provided and can be positioned inside the housing of the main body wherein the drilling heads are maintained in the housing by a retention plate. The device can be held by the user at the handle.
Based on this prior art, it is one aspect of the present invention to provide a soft tissue protector guide being adapted for aiming different diameter drill bits and implants; saving surgical time during implant insertion; decreasing soft tissue injury during surgery and decreasing the number of parts a surgeon needs to manipulate for standard surgical procedures.
It is a further aspect of the invention to improve positioning of implants of different sizes using a single tool as tissue protector.
The above mentioned goals are achieved through a soft tissue protector and drill guide for guiding elements of an implantation kit during a surgical intervention. The drill guide includes a soft tissue protector main body, a gripping portion attached at the soft tissue protector main body, a rotatable adjustment cap mounted on the main body and a plurality of jaws defining a through going cavity along the longitudinal axis of the soft tissue protector main body. The jaws have inner jaw surfaces, wherein the through going cavity has an upper and a lower opening for receiving the element to be guided, wherein the jaws engage the adjustment cap as well as the soft tissue protector main body. The soft tissue protector main body has a lower contact surface to be positioned on a bone on or into which a bone screw is to be guided. The diameter of the through going cavity can be varied. The adjustment cap can be rotated against the soft tissue protector main body forcing the jaws radially apart providing the variable diameter of the through going cavity with their inner jaw surfaces. The elements of an implantation kit are drill bits and implants. Each jaw comprises a flexible guiding extension ending near the lower opening of the drill guide. The flexible guiding extension comprises, at the free end of the guiding extension, a guide spring oriented away from the longitudinal axis of the guiding extension, contacting the inner wall of the drill guide sleeve and pushing the inner jaw surfaces of the flexible guiding extension one against the other. This allows passage of the elements against the action of the spring. Each jaw comprises a stiff upper jaw body being radially guided in the drill guide body and connected to the flexible extension. Each upper jaw body comprises a first guide, wherein the tissue protector main body comprises a complementary second guide for each first guide of the upper jaw body, allowing for a radial movement of the upper jaw body upon rotation of the main body against the jaws. The first guide may be slide blocks and the complementary second guide are spiral grooves extending from an inner position end to an outer position of each groove end each groove adapted to receive a slide block of one jaw body. Each upper jaw body comprises a rotating element, wherein the adjustment cap provides the upper opening and comprises complementary rotation element for each rotating element of the jaws engaging them for providing a rotation of the jaw bodies against the tissue protector main body when the cap is rotated. The rotating element is a pin and the complementary rotation element for each pin is a radially oriented slot engaging each pin for allowing the radial movement of the jaw during a rotation of the jaw bodies. The soft tissue protector and drill guide may comprise at least three jaws. In the innermost position the walls of adjacent jaw bodies contact each other, thus providing a completely surrounded inner through going cavity.
Thus the soft tissue protector and drill guide for guiding elements, especially drill bits and implants such as bone screws of the implantation kit during an surgical intervention, includes a soft tissue protector main body having a gripping portion. The drill guide has an upper and a lower opening along its longitudinal axis with a through going cavity for receiving the element to be guided, and a lower object contact surface to be positioned on an object on or into which said element is to be guided. The diameter of the through going cavity can be varied. The soft tissue protector and drill guide comprises a number of jaws engaging an adjustment cap as well as engaging the main body, wherein the adjustment cap can be rotated against the main body forcing the jaws radially apart providing the variable diameter of the through going cavity with their inner jaw surface.
It is an advantage for a centered guiding of elements like drills into a guide, where each jaw comprises such a flexible guiding extension ending near the lower opening of the drill guide. Each flexible guiding extension comprises, at the free end of the guiding extension, a guide spring oriented away from the longitudinal axis of the guiding extension. The spring contacts the inner wall of the drill guide sleeve and pushes the inner jaw surfaces of the flexible guiding extension one against the other, allowing passage of drill or implant elements against the action of the spring, which elements are readily centered from the beginning of the introduction.
The mechanism according to the invention allows concentric translation of different planes aimed to orient drill bits of different diameters along the same axis and driving the drills and implants during insertion and protecting the soft tissues. The concentric translation of the planes is driven by the mechanism of the present invention to determined positions. The features of the mechanism allow for the planes stability in each position to drive a drill bit or to drive the insertion of a surgical implant. The mechanism is designed that it can be easily disassembled and cleaned.
A drill guide or other element lower contact surface is therefore positioned on an object, such as a bone, on or into which the element is to be guided, wherein the diameter of the through going cavity can be varied by a.) positioning of four jaws inside the cavity and/or b.) against the force of a spring at the lower free end of the guiding extension provided on the back side of the extension against the inner wall of the drill guide sleeve.
The user of the device applies a method for adapting the diameter of the drill guide to a specific drill he intends to use, comprising the method steps of:
providing a soft tissue protector and drill guide for guiding elements according to the invention,
turning the adjustment cap mounted on the main body in a direction, engaging the jaws which turn and move radially apart providing the maximum adaptable diameter of the through going cavity with their inner jaw surface for the upper jaw bodies,
introducing the element to be guided through the upper predefined opening of the adjustment cap through the through going cavity with the inner jaw surface, and
rotating the adjustment cap in the opposite direction to close the jaws on the element to be guided.
It is especially advantageous that the step of introduction comprises an advancement of the element to be guided into the extension portions of the jaws which are closed to the minimum diameter at the lower free ends until they are pushed one away from the other by the introduction of the element to be guided against the force of spring elements on the backside of the flexible guiding extension, allowing the passage of said elements against the action of the spring being biased against the inner wall of the drill guide sleeve.
A further aim of the springs is to provide the moving flat surfaces support where they are thinner and then it is not intended that the distal portion of the lower surfaces exert an important force radial to the drill because this could make the drill extraction difficult.
Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings,
The drill guide head 30 extends above the handle attachment flange 21 whereas the drill guide sleeve 31 is fitted into the handle attachment flange 21. As can be seen from
The internal form of the guide cavity 49 (
The four jaws 60 each covering 90 degree of the walls of the internal cavity 49 are shown in
As will be seen in connection with the explanation of
It can be seen from
Upon rotation of the four jaws 60 through rotation of the adjustment cap 33 slide blocks 66 of each jaw 60 (shown in
The orientation of the groove 76 in the embodiment shown starts with a slightly curved slot at the smallest distance from the centre of the device with a growing curvature until about to two third of its lengths when it turns around into an almost tangential direction until it ends at the outer end 72 of groove 76. The choice of the curvatures follows the possible sizes of the drill bits and implants used in connection with this drill guide and provide good functionality for the intended rotation. As can be seen from
Extension 40 can be attached to the sleeve 31 through teeth or mating embossments 45 enter into mating grooves 44 and the same teeth can, as seen in
The description relating to
From
It is also possible that, If the upper jaws 61 are open, the lower inner surfaces 61 have the same distance one from another when they are stiff, in this case the springs 68 do not press these surfaces together and close them at the extension free end 69.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
Number | Date | Country | Kind |
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12150401.3 | Jan 2012 | EP | regional |