Patent Description:
The medical industry has made use of both reusable and disposable tools and handles. In a surgical context, there is little room for error and the devices must be precise and simple for a surgeon to use during procedures.

Orthopedic surgical procedures can require the creation or enlargement of holes in bones, affixation or removal of fasteners and the like.

Reusable devices require constant recalibration and sterilization to avoid contamination.

<CIT> relates to an orthopaedic surgical rasp comprising a metallic cutting insert and a handle molded thereto. <CIT> relates to disposable bone cutting instrument, in particular a helical reamer for reaming a bone cavity has a longitudinally extending support shaft having a first driven end and a second end having a tip for insertion into the bone cavity. <CIT> relates to a surgical knife having a blade and a handle integrally molded on the blade.

Aspects of implementations of devices and methods of a disposable cutting tool with an elongated molded body with a proximal end and a distal end. A handle portion formed hear the distal end and a support shaft formed near the proximal end, and the support shaft affixed to the rasp head having a height, a top side and a bottom side via portions of the body co-molded into fluid connections within the rasp head.

The tool, has a molded neck region extending from the body and formed within the fluid connection. A molded collar region is connected to the neck region and formed within a fluid passageway in the rasp head. The passageway extends into sides fluidly connected to the passageway.

The passageway may be one or more of orthogonal and perpendicular to the shaft extending from the top side to the bottom side of the rasp head; at an acute angle to the shaft; at an oblique angle to the shaft; and "Y" shaped extending from the top side to the bottom side of the rasp head.

In some instance at least one of the rasp head and the support shaft are tapered. In some instances wherein at least one of the top side and bottom side of the rasp head is parallel to the axis of the rasp head and the other side is angled relative to the axis of the rasp head, in other instances at least on side is convex or concave relative to the other side.

Aspects of implementations of devices and methods of an ergonomic disposable rasp with an elongated molded body with a proximal end and a distal end having non-circular regions in cross section on the handle portion the support shaft affixed to the rasp head having a height, a top side and a bottom side via portions of the body co-molded into fluid connections within the rasp head; and, wherein the non-circular regions provide preselected griping surfaces on the handle. In some instances the non-circular regions are at least one of divots, bumps and non-homogeneous generally flat regions.

Aspects of implementations of devices and of attaching a rasp head, the method including forming a metal rasp head having a fluid pathway there through then molding an elongated body with support shaft co-molded into the rasp head via said fluid pathway with the fluid pathway branching into one or more sides. In some instances the branches are formed at one of an actuate and oblique angle to the shaft.

The general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as defined in the appended claims. Other aspects of the present invention will be apparent to those skilled in the art in view of the detailed description of the invention as provided herein.

The summary, as well as the following detailed description, is further understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings exemplary implementations of the invention; however, the invention is limited only by the appended claims.

In addition, the drawings are not necessarily drawn to scale.

Rasp tools are an essential part of many surgical procedures. When implanting support devices or replacing bone, a rasp is a commonly used instrument to prepare surfaces for connection. Rasp may also be used to file down bone or alter connecting tissue. Important to any surgery is to minimize contamination, infection and costs.

<FIG> and <FIG> show exterior perspective views of a hybrid rasp tool <NUM>. The body <NUM> is a plastic injection molded elongated member with a distal end and a proximal end. The handle portion <NUM> is at one end and the rasp head <NUM> is at the opposite end. The handle portion may be configured to have varying surface region <NUM> with features such as bumps <NUM> or divots <NUM>. The bumps and divots may form ring like geometries round all or a portion of the varying surface region <NUM>. The varying surface region may be adjacent to a tubular region <NUM>. The tubular region may have one or more non-homogeneous gripping areas <NUM> such as a flat area configured to press a thumb or finger against during griping.

The handle portion may taper via a neck <NUM> to a smaller diameter support shaft <NUM>. In cross section the shaft may be generally circular. In some instance the portion of the shaft adjacent to the rasp head <NUM> may be asymmetrically tapered via a tapered region <NUM> to narrow the shaft to the height of the rasp head <NUM>. The tapered region may be positioned along one or both of the top and bottom faces of the rasp head.

<FIG> shows a rear perspective view of the rasp tool. <FIG> and <FIG> show side views of the rasp tool of <FIG>. The distal end <NUM> of the body is visible. <FIG> shows a cut-away view of the hybrid rasp of <FIG> along the line of "A-A". The body is non-metallic, should be moldable via injection molding, and may be formed of plastics, composites, resins, glass filled plastic or resins and the like.

The rasp body may also have non-homogeneous gripping areas <NUM> opposite each other. Important when using a rasp device is that the user have a firm grip. During a surgical procedure a surgeon will often have fluids and material on gloves and such fluids will acts as a lubricant thereby promoting slippage of the hand from a grip. By contouring the body with non-homogeneous gripping areas <NUM> and bumps and divots the user's grip may be improved and slippage reduced. A disposable rasp tool allows fort the disposal of all medical waste associated with the tool during disposal of the tool. Unlike metal rasp tools a hybrid rasp tool may be configured to provide flex to assist the user in positioning and using the tool. The rasp head <NUM> may be configured with concave, convex, flat or tapered top sides and /or bottom sides. The rasp head or heads (in a kit of rasps) may also be formed to mimic the normal lordosis shape of a spine at a predetermined vertebral level. The rasp head or heads (in a kit of rasps) may also be formed to mimic non normal shapes of a spine and thereby selected to match a shape presented by a specific spine. Shown in <FIG> is a tapered rasp head with a first height "h1" at the proximal end of the rasp <NUM> and measured between the top side of the rasp <NUM> and the bottom side of the rasp <NUM>. The rasp head has a second height "h2" at the distal end of the rasp <NUM> and measured between the top side of the rasp <NUM> and the bottom side of the rasp <NUM>. The taper can be seen along the side wall <NUM> of the rasp head. The shaft <NUM> may also be tapered from the shaft cross sectional height "sh1" to a non-circular cross sectional height "sh2" forming shaft regions adjacent to the rasp faces generally the same as the rasp head second height. Cutting features <NUM> of the rasp are shown in a regular pattern on each side of the rasp head. The taper shown on the rasp head and the body is not a limitation. Tapers may vary or be eliminated in some aspects of some embodiments. The rasp is a cutting tool and those of ordinary skill in the art will recognize that drills, scrappers, scalpels, blades and resectors may be connected via the disclosed co-molded process to the handle in lieu of the rasp head, however such cutting tool are not within the scope of this invention. See generally <FIG>.

Shown in <FIG> are aspects of the rasp head attachment. The rasp head <NUM> is fixed permanently at the proximal end <NUM> of the body. The material selected to form the body <NUM> should be configured to provide a predetermined amount of rigidity or flex along its axial length to balance the intended use, which may include the body bending a predetermined amount with the need to support the rasp head <NUM> for its intended use of resection. During resection the rasp head should have limited displacement off axis from the body and that limit of displacement may be the result of material choices.

The body material will also form the neck region <NUM> collar <NUM> and collar ends 170A and 170B of the body component. Shown in <FIG> and <FIG> are the neck and arms. <FIG> shows a cut a-away view of an assembled hybrid rasp device wherein the placement of the neck <NUM>, collar <NUM> and collar ends 170A/170B relative to the rasp head are shown.

The rasp head <NUM> is configured to resect bone or tissue at a surgical site. Accordingly, the rasp head should be constructed of a material of sufficient hardness to accomplish same. Moreover because the rasp head can be co-molded with the body, it needs to withstand the pressure, thermal changes associated with injection molding. By co-molding the rasp head to the body a compact rasp tool is constructed eliminating catches and latches to connect a rasp head to a support member.

Although the rasp head shown in <FIG> is illustrated as a single piece the rasp head may be formed of two or more parts combined together prior to co-molding. In some instances the rasp head will be a ceramic or metallic material. One opening <NUM> to the lateral passageway is also shown.

<FIG> illustrates a cut-away view of the rasp head. A fluid connection <NUM> oriented axially to the body is formed into the rasp head. The fluid connection <NUM> intersects with and is fluidly connected to lateral passageway <NUM> which run perpendicular to the body. The lateral passageway <NUM> has a first side 270A and a second side 270B formed respectively on either side of the fluid connection <NUM>. The fluid connection and the lateral passageway together form a cavity through the rasp head by which the injection molded material will pass during production of the device. The lateral passageway is configured to allow the injection material to flow through.

<FIG> shows a sectional top view of a rasp head <NUM> with a "Y" shaped channel having a fluid passageway <NUM> with sides 304A and 304B at oblique angles from the fluid connection <NUM>. <FIG> shows a sectional top view of a rasp head <NUM> with an arrow shaped channel having a fluid passageway <NUM> with sides 404A and 404B at acute angles from the fluid connection <NUM>. <FIG> shows a cross sectional view of a rasp head <NUM> with a "T" shaped channel with sides 504A and 504B orthogonal to the shaft and fluid passageway <NUM> spanning from the top side <NUM> to the bottom side <NUM> of the rasp head. <FIG> shows a cross sectional view of a rasp head <NUM> with a "Y" shaped channel with sides 504A and 504B orthogonal to the shaft and fluid passageway <NUM> spanning from the top side <NUM> to the bottom side <NUM> of the rasp head.

<FIG> show side view of several rasp head. <FIG> shows a side view of rasp head <NUM> with parallel sides <NUM> and <NUM>. <FIG> shows a side view of a rasp head <NUM> showing an axis of the rasp head <NUM> which is parallel or flat to the bottom side <NUM> and a top side <NUM> that is tapered relative to the axis of the rasp head. <FIG> shows a side view of rasp head <NUM> which has a complex shape shown as a convex top side <NUM> and a convex bottom side <NUM>. In this implementation the center of the rasp head is the height point at height two "h2" and with a lesser height at height one "h1" and height three "h3". The skilled artisan and those of ordinary skill in the art will recognize that <FIG> may be convex or concave on one side and flat on another side.

<FIG> illustrates a disposable cutting device <NUM> with a plastic shaft <NUM> co-molded to a support collar <NUM> affixed to a blade <NUM>. Collar end 170B can be seen through lateral passageway <NUM> which is fluidly connected to fluid connection <NUM> oriented axially to the shaft and collar.

<FIG> illustrates a disposable cutting device <NUM> with a plastic shaft <NUM> co-molded to a support collar <NUM> affixed to a drill <NUM>. Collar end 170B can be seen through lateral passageway <NUM> which is fluidly connected to fluid connection <NUM> oriented axially to the shaft and collar.

<FIG> illustrates a disposable scraping device <NUM> with a plastic shaft <NUM> co-molded to a support collar <NUM> affixed to or formed as part of a scraper <NUM>. Collar end 170B can be seen through lateral passageway <NUM> which is fluidly connected to fluid connection <NUM> oriented axially to the shaft.

Those of ordinary skill in the art will recognize that the scope of the invention includes non linear lateral passageways and lateral passageways which may have additional branches. The lateral passageway is configured to retain injection material in a fashion that fixes the rasp head to the body and prevent rotation of the rasp head on the body within the parameters of intended usage.

While the method and apparatus have been described in terms of what are presently considered to be the most practical and preferred implementations, it is to be understood that the invention need not be limited to the disclosed implementations. It is intended to cover various modifications and similar arrangements included within the scope of the claims.

Further, the use of the transitional phrase "comprising" is used to maintain the "open-end" claims herein, according to traditional claim interpretation. Thus, unless the context requires otherwise, it should be understood that the term "compromise" or variations such as "comprises" or "comprising", are intended to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps.

Claim 1:
A disposable cutting tool comprising:
an elongated molded body with a proximal end (<NUM>) and a distal end (<NUM>);
a handle portion (<NUM>) formed near the distal end and a support shaft (<NUM>) formed near the proximal end;
a rasp head (<NUM>) having a height, a top side (<NUM>), a bottom side (<NUM>) and a fluid connection (<NUM>);
the support shaft affixed to the rasp head (<NUM>) via portions of the body co-molded within the rasp head;
the portions of the body co-molded within the rasp head comprising a molded neck region(<NUM>) formed within the fluid connection (<NUM>);
characterized in that the portions of the body co-molded within the rasp head further comprise a molded collar region (<NUM>) connected to the neck region and formed within a passageway (<NUM>) in the rasp head; said passageway (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) being fluidly connected to the fluid connection (<NUM>) and comprising a first side (270A) and a second side (270B) formed respectively on either side of the fluid connections (<NUM>).