In-bone implantable shaft for prosthetic joints or for direct skeletal attachment of external limb prostheses and method of its installation

Abstract

An in-bone implantable shaft for prosthetic joints or for direct skeletal attachment of external limb prostheses, comprised of a central body fitted in the zone of the bone's medullary cavity conventionally prepared for implantation, and of side elements attached to the central body and fitted in the slots specially made in the bone's walls surrounding said medullary canal; said side elements have spaces between them, arranged to be filled by bone cells to provide a natural and safe osseolocking of the shaft. A method of preparing the bone for implantation of a prosthetic shaft, comprising the steps of: placing a cylindrical guide with slots made in the longitudinal direction of said guide inside said bone's canal which is conventionally prepared for implantation; cutting said bone's walls by progressing a saw along the edges of the slots of said guide; removing the guide; fitting the shaft in the bone's canal, provided that the side elements are fitted to the slots in the bone's walls.

Description

TECHNICAL FIELD[0001]Prosthetics, surgical instruments; more particularly, methods and devices for surgically preparing a bone for the implantation of a prosthetic implant component of a prosthetic joint [1, 2] or the implantation of an abutment for direct skeletal attachment of external prostheses, as described in: http: / / www.sahlgrenska.se / vgrtemplates / Page—33031.aspx.BACKGROUND OF THE INVENTION[0002]This invention relates to prosthetic implants for skeletal replacement, reconstruction and attachment in humans and animals, and, more particularly, to the design and method of installation of such devices that would reduce their loosening with time.[0003]Implantable devices are used to partially or completely replace joints or bone segments in humans and animals, or to provide direct skeletal attachment of external prostheses to the residuum.[0004]The known approaches to attaching the implants include fitting the implant into the medullary canal of the bone by force; securing the imp...

AI Technical Summary

Benefits of technology

[0017]The present invention relates to the creation of favorable conditions for the ingrowth of bone cells and tissues between and throughout the sides of the implanted shaft (“osseolocking”). To increase the positive effect of osseolocking, the bone walls are specially prepared in conjunction with the standard drilling of the medullary canal. That specific preparation includes fashioning one or more slots in the bone walls in the longitudinal direction. The protruding sides of the installed implant are positioned in the slots, and the ossification begins. That ossification process between and throughout the side elements progresses in the direction of the widening bone, and is able to naturally lock the implant's shaft with an anchoring effect similar to the inter-locking nailing, but without its complications [16].

Problems solved by technology

One of the major problems involved in the use of such devices is the loosening of the attachment between the prosthetic implant and the associated bone.

One of the reasons for loosening, after all these approaches or their several combinations are used, is that the approaches are all in conflict with the structure and function of the medullary cavity canal, into which the implants are inserted.

However, the preexisting position of the endosteum limits the potential volume of the remodeled ossified bone tissue in the outward-inward direction.

However, this approach has never been applied to lock the implanted shaft.

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