Joint surface replacement system
Inventors
Vitale, Glenn C. • Parisi, Michael • CONLAN, WAYNE
Assignees
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Publication Number
US-11039928-B2
Publication Date
2021-06-22
Expiration Date
Abstract
The present invention relates to an articular joint replacement system. The system has first and second components. Each component has a tapered head piece for covering the end of a bone and for acting as an articular surface, an integrally formed screw stem having a length sufficient to extend into the medullary canal, and inwardly angled bone grips affixed to the underside of the head piece to allow solid fixation to the bone by compression press fit. The head piece of the first component is provided with a shaped exterior surface which complements the shaped exterior surface of the head piece of the second component and which allows motion in three planes.
Core Innovation
The disclosed invention is an articular surface replacement component for replacing an end of a first bone. The component includes an exterior articular surface defined by a concave head piece dimensioned to cover the end of the first bone, with an interior surface, an exterior surface, and an outer periphery connecting the interior and exterior surfaces. The interior surface is a smooth contiguous surface area, while recessed features in the interior surface are provided to promote fixation.
Fixation is achieved through a plurality of recessed channel-shaped anti-rotation bone grips located in the interior surface of the concave head piece. The recessed channel-shaped anti-rotation bone grips are configured to allow ingrowth of the first bone therein to improve resistance to rotation and to support solid fixation. The bone grips are described with a longitudinal/radial extending configuration extending from adjacent the outer periphery to adjacent a centrally located stem.
The component further includes a centrally located stem extending from the interior surface of the concave head piece, and a plurality of threads extending around the stem. The assembly is positioned as part of an articular surface replacement system using a concave head piece with recessed anti-rotation grips and a centrally located stem to achieve stable motion in multiple planes. The disclosed concepts are associated with using coarsely finished surfaces and bone growth coating options, and with replacing or preserving subchondral bone functions depending on the specified configuration.
Claims Coverage
The partial claim set includes two independent claims. Across the independent claims, the inventive structure is focused on a concave head piece with a smooth contiguous interior surface containing recessed channel-shaped anti-rotation bone grips for ingrowth, together with a centrally located stem and threads extending around the stem.
Concave head piece covering the bone end
An exterior articular surface defined by a concave head piece dimensioned to cover the end of the bone, the concave head piece having an interior surface, an exterior surface, and an outer periphery connecting the interior and exterior surfaces.
Smooth contiguous interior surface with recessed channel-shaped anti-rotation bone grips
The interior surface of the concave head piece is a smooth contiguous surface area having a plurality of recessed channel-shaped anti-rotation bone grips recessed therein, each extending longitudinally in a radial direction from adjacent the outer periphery of the concave head piece to adjacent the centrally located stem.
Centrally located stem extending from the concave interior
A centrally located stem extending from the interior surface of the concave head piece.
Threads extending around the centrally located stem
A plurality of threads extending around the stem.
Solid fixation using radially-extending recessed channel-shaped anti-rotation bone grips
A plurality of radially-extending recessed channel-shaped anti-rotation bone grips in the interior surface of the concave head piece that allow for ingrowth of the bone therein to solidify fixation.
Across the independent claims, the central inventive theme is an articular surface replacement component with a concave head piece whose smooth contiguous interior surface carries recessed radially extending channel-shaped anti-rotation bone grips to allow bone ingrowth for fixation, together with a centrally located stem and threads around the stem.
Stated Advantages
Elimination of implant pistoning/loosening.
Preservation of subchondral bone/shock absorption.
Elimination of detritic synovitis.
Improved stability and anti-interference with range of motion.
Low-mass components to reduce breakage and bulk.
Documented Applications
Two-component joint/articular surface replacement system for an end of a first bone, including an example of a phalangeal component.
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