Intramedullary Nail

Abstract

A versatile intramedullary nail is constructed in two cooperating and optionally interlocking pieces, with a further optional annular restoration hub. The two cooperating pieces, when interlocked, approximate a long shaft, generally tubular in cross-section, with a recessed area on the male piece adapted to receive the annular restoration hub. The female piece is adapted to receive the flange of the male piece coaxially, and—unless a locking screw or bolt is inserted through the flange—the two pieces can rotate axially. Alternatively, the nail can be constructed of a single solid piece.

Description

BACKGROUND AND CROSS REFERENCE[0001]1. Field of the Invention[0002]The present invention is a versatile nail for use in the intramedullary canal of the ulna or the fibula, and claims priority to U.S. Patent Application Ser. No. 62 / 036,426 filed 12 Aug. 2014 and No. 62 / 039,275 filed 19 Aug. 2014, each of which is incorporated herein by reference.[0003]2. Description of Related Art[0004]Intramedullary nails are known in the art, and are widely used throughout the world to repair fractures or to reinforce bone shafts during and after surgery of various types. The intramedullary canal (synonymous with the marrow canal) is an ideal place for insertion of a support structure, because the relatively softer bone or marrow provides an easy implantation site, and intramedullary implants are less compromising to bone than other bone inserts. Traditional intramedullary nails or rods have typically been secured with locking bolts or screws to the adjacent bone, to prevent unwanted rotation, and ...

AI Technical Summary

Benefits of technology

[0007]In order to meet this need, the present invention is a versatile intramedullary nail constructed in one piece or in two cooperating and optionally interlocking pieces, with a further optional truncated annular restoration hub. The two cooperating pieces, when interlocked, approximate a long shaft, generally tubular in cross-section, with a recessed area on the male piece adapted to receive the truncated annular restoration hub. The female piece is adapted to receive the flange of the male piece coaxially, and—unless a locking screw or bolt is inserted through the flange—the two pieces can rotate axially and independently of each other. (Alternatively, the aforesaid nail structures can be manufactured as a single piece and, in such case, no interior rotation will take place.) Bolt or screw holes near the ends of either piece allow selective anchoring of either or both pieces to the adjacent intramedullary bone. However, if the interconnected pieces are interlocked and only one piece is bolted or screwed to the adjacent intramedullary bone, the other piece can rotate freely within the intramedullary canal to restore range of motion to an adjacent joint. Conversely, if the interconnected pieces are each bolted or screwed to their respective bone but the interconnection is NOT interlocked, then the two pieces maintain their lengthwise rigidity but can rotate axially depending on exertion from an adjacent joint. The present intramedullary nail or plate is particularly suited for use within the ulna or fibula, especially after wrist or even ankle joint fusion creates a need for improved range of motion in the hand or foot.

Problems solved by technology

One disadvantage of a traditional intramedullary nail inhered in its elongated length: surgical implantation was often complicated simply by the sheer size of the nail.

Also, prior art intramedullary nails and rods were typically designed to be completely stationary within the bone, and hold the bone immobile-specifically not allowing motion within the bone but only at the adjacent joint.

However, having the ulna in two pieces, with only one end of each piece's being securely anchored, created problems of its own such as instability of the proximal ulna stump, even though the osteotomy did restore some range of motion after the fusion.

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