Self-boring and self-tapping screw for osteosynthesis and compression

Abstract

The invention provides an osteosynthesis and compression screw that is self-boring and self-tapping for the purpose of coaptation of small bone fragments. The screw comprises:a proximal portion formed by a screw head provided with an outside thread;an intermediate portion having no thread; anda distal portion provided with an outside thread.Wherein:each of the screw head and the distal portion includes at least one groove, firstly extending over the entire axial length of its thread, and secondly being formed through each thread in such a manner to form tapping means; andthe terminal zone of the distal portion is provided with preparation means for preparing a housing in the bone fragments for receiving the intermediate and distal portions of the screw.

Description

CROSS REFERENCE RELATED APPLICATION[0001]This application is a continuation application, which is based on and claims priority to co-pending U.S. Utility patent application Ser. No. 10 / 614,496, filed on Jul. 7, 2003, which claims priority to French Application No. 02 08589, filed Jul. 5, 2002, which is entirely incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates to the technical field of surgical screws, and in particular to osteosynthesis screws for joining together and compressing two bone fragments in order to achieve rapid osteosynthesis with the formation of bone callus, the present invention applying more particularly to joining together small bone fragments such as those of the phalanges of the toes or the fingers.[0003]The present invention relates to an osteosynthesis and compression screw for coaptation of small bone fragments, the screw being formed by a single longitudinal body, and comprising:[0004]a proximal portion formed by a sc...

AI Technical Summary

Benefits of technology

[0018]The present invention consequently seeks to remedy the various drawbacks outlined above and to propose a novel osteosynthesis and compression screw for coaptation of small bone fragments, which screw is self-boring and self-tapping so as to simplify installation thereof and so as to enable installation to be controlled as well as possible.

[0019]Another object of the invention is to propose a novel osteosynthesis screw which is not only self-boring and self-tapping, but which also presents excellent strength properties.

Problems solved by technology

When dealing with broken bone fragments of small size, such as those of the phalanges or the toes, the small size of the bones or bone fragments concerned poses difficult problems to be solved by the practitioner in charge of reducing the fracture and then putting the bones into place with sufficient compression to ensure that the fracture is properly resorbed.

Clearly, given the very small size of the bone fragments concerned, and the correspondingly small size of the osteosynthesis screws used, it is difficult to establish longitudinal compression between the two bone fragments concerned.

It is particularly important and difficult to master this type of surgical act, given that the manipulations imposed by the small size of the bones and the screws are fiddly, and given that the small bone fragments need to be positioned relative to one another and compressed and put into final position with very great precision since the purpose is to restore total mobility functions, such as handling functions or walking, in particular when dealing with bones of the hand or of the foot.

Such a technique is poorly adapted to the type of surgery under consideration insofar as putting staples into place relative to the pieces of bone does not make it certain that the bone fragments to be joined together are properly positioned.

In practice, it is not possible with staples to obtain fixing and compression.

Nevertheless, such screws still suffer from drawbacks associated in particular with a certain number of additional actions that the surgeon needs to perform such as prior drilling of a hole in order to ensure that the threads of the screw hold strongly both in the distal portion and in the proximal portion having the head of larger diameter.

This increases the number of actions the surgeon needs to perform and therefore increases the duration of the operation.

Such screws thus require an additional tool to be used which implies an 30 additional act leading to increased manipulation, to additional risk of accidents or faulty installation, and, in all, lengthening the time required for surgery.

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