SURGICAL INSTRUMENT

Featured is a surgical instrument having an elongate inner tubular member and an elongate outer tubular member, in which the inner tubular member is moveably received within the outer tubular member. The instrument also includes a diamond-like carbon (DLC) surface disposed so as to be between the inner and outer tubular members. In further embodiments, the DLC surface is formed on the outer surface of the inner tubular member and/or on the inner surface of the outer tubular member. In yet further embodiments, the inner tubular member includes a cutting edge disposed at a distal region thereof, and the outer tubular member includes a distal opening therein. The opening is positioned to expose and co-operate with the cutting edge of the inner tubular member to permit shearing or cutting of tissue.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the various figures of the drawing wherein like reference characters refer to like parts, there is shown inFIG. 1a surgical cutting instrument10according to an aspect of the present invention. Such a surgical cutting instrument includes an elongate outer tubular member11coupled at a proximal end12to a major hub component13. A distal end14of the outer tubular member11includes an opening15which forms a cutting port or window.

The surgical cutting instrument10further includes an elongate inner tubular member20, more readily illustrated inFIG. 2. The inner tubular member20is coupled at a proximal end21to a minor hub component22, and includes a distal end23having a cutting edge24. The minor hub22and inner tubular member20are rotatably received in the major hub13and outer tubular member11, respectfully, such that the distal ends of the inner and outer tubular members abut, and so that the cutting edge24is positioned adjacent the opening15so the cutting edge can engage bodily tissue/bone for purposes of cutting same.

Such a surgical cutting instrument and the parts thereof are generally made from bio-compatible materials (e.g., plastic or metals) that are appropriate for the intended use. For example, the inner and outer tubular members20,11are constructed using a biocompatible metal such as for example, stainless steel or titanium.

The minor hub22includes a transverse bore25, into which the inner tubular member20partly extends, and a proximal region30for engagement with a drive shaft of an electric motor (or other driving mechanism known in the art, e.g., a pneumatic motor) in a handpiece, not shown. Such an electric motor typically includes gearing or other such mechanisms known in the art that couples the motor to the drive shaft and are for controlling the rotational speed and torque being delivered. The electric drive shaft is coupled (e.g., mechanically coupled) to the inner tubular member using any of a number of techniques known to those skilled in the art for rotationally driving the inner tubular member.

The opening15in the distal end of the outer tubular member11extends through the side and end walls to produce an edge which, in use, cooperates with the cutting edge24of the inner tubular member20. The opening20and cutting edge or edges24can have any number of configurations as are known in the art or hereinafter developed, depending on their intended use, as long as the configurations are suitable for cooperating with each other to provide a surgical blade or the like that is suitable for cutting tissue and/or bone. In exemplary embodiments, the opening and cutting edge or edges can combine or cooperate to form surgical trimmers, meniscal cutters, end cutters, side cutters, full radius cutters, synovial resectors, whiskers, open end cutters, arthroplasty burrs, slotted whiskers, tapered burrs, or oval burrs.

In use, the inner tubular member20is rotatably driven within the outer tubular member11such that the cutting edge24engages body tissue through the cutting port or window formed by opening20. The cut or processed tissue is aspirated through the lumen of the inner tubular member and to exit the surgical cutting instrument via transverse bore25, which communicates with a suction passage in the handpiece.

Referring now toFIGS. 3 to 6, various different exemplary embodiments of the present invention are shown in which the surfaces in regions of the tubular members are coated with a diamond-like carbon (DLC) material.

Such diamond-like carbon material can be used as a coating material to impart some of the properties of diamond, such as hardness, wear resistance, slickness and smoothness, to a material upon which it is coated. Diamond-like carbon is observed in seven different forms and can be applied to almost any material that is compatible with a vacuum environment. Thus, DLC coatings with no extended crystalline order can be produced. This results in materials with no brittle fracture planes, such that peeling and cracking of the surface coating is virtually eliminated. These DLC coatings are flexible and readily conform to the particular shape of the article being coated, whilst retaining the characteristic hardness properties of diamond. Such diamond-like carbon can embody different crystalline polytypes such as carbon atoms arranged in a cubic lattice or in a hexagonal lattice (sp3bonded carbon atoms).

FIG. 3shows a section of the inner tubular member ofFIG. 2, along the line A-A. As shown, according to an embodiment or another aspect of the present invention the outer surface of the distal region of the inner tubular member includes a coating31of diamond-like carbon. Referring now toFIG. 4, there is shown another embodiment or aspect of the present invention in which the inner surface of the distal region of the outer tubular member11includes a coating32of diamond-like carbon. The coated surface in each illustration acts as a bearing surface to prevent wear and the shedding of metallic particulates. In yet a further aspect or embodiment of the present invention, both the outer surface of the inner tubular member and the inner surface of the outer tubular member are provided with such a coating or bearing surface.

The bearing surface can be a circumferential bearing surface, as illustrated inFIGS. 3 and 4, an end bearing surface, as shown inFIGS. 5 and 6, or it can be a combination of the two. Also, the circumferential bearing surface is configurable so as to extend along the length of either the inner and/or outer tubular members from the distal end of the instrument for a length sufficient to provide an elongate bearing surface between the inner and outer tubular members. As discussed above, the DLC coating can be applied to an inner surface of the outer tubular member, an outer surface of the inner tubular member, or it can be applied to surfaces of both the outer tubular member and the inner tubular member.

Although the end bearing surfaces of the inner and outer tubular members are illustrated as being spherical or hemi-spherical in shape, this is not limiting as it is within the scope of the present invention for the ends of the tubular members to be configured and arranged so as to provide any of a number of bearing surface arrangements as is known in the art and otherwise appropriate for the intended use.

In yet further embodiments/aspects of the present invention, the DLC coating is applied to the cutting edge and/or opening or cutting port or window so that the cutting region benefits from the properties of the coating material.

The DLC coating as described herein preferably has a thickness of from about 0.001 to 10.0 micrometers, with a hardness of between about 1,500-3,500 Vickers (approx. 14-34 GPa). The coating will typically have a coefficient of friction of less than 0.2. In preferred embodiments, the coefficient of friction is less than 0.15; most preferably less than 0.1. In more particular embodiments, the properties of the DLC coating are such that the hardness is in the range of 1,500-3,500 Vickers (approx. 14-34 GPa) and the coefficient of friction is in the range of 0.2 to about 0.05, more specifically the coefficient of friction is one of less than 0.2, 0.15 or less than 0.1.

The DLC coating is not shown to scale in the illustrated examples as, in practice, the coating is so thin that it could not be otherwise illustrated.

In alternative embodiments, the inner tubular member is coated on its inner, on its outer, or on its inner and outer surfaces. A DLC coating on the inner surface is expected to help to prevent sticking and clogging of aspirated tissue. In further alternative embodiments, the outer tubular member is coated on its inner, on its outer, or on its inner and outer surfaces. A coating on the outer surface is expected to assist with the movement of the instrument through tissue, and also during cutting.

The DLC coating can be any of its known forms, i.e. pure tetrahedral amorphous carbon with all sp3bonded carbon atoms, or one of the other forms containing sp3and sp2bonded carbon atoms. As indicated herein, the coating also can include a filler(s) such as hydrogen and metal.

In yet further embodiments or aspects of the present invention, the DLC material selected for coating a surface can have different properties from the DLC coating being applied to an opposing surface. For example, a first DLC coating having a first set of properties is applied to the outer surface of the inner tubular member and a second DLC coating having a second set of properties is applied to the inner surface of the outer tubular member, where the first and second set of properties are different from each other. Also, for example, the DLC coating(s) applied to the outer surface of the outer tubular member and /or the inner surface of the inner tubular member can be different from the properties of the DLC coating(s) applied between the inner surface of the outer tubular member and/or the outer surface of the inner tubular member.

EXAMPLES

A DLC coating having a thickness of3micrometers was applied to the entire outer surface of an inner tubular member. A coating of the same thickness was applied to the inside surface of the outer tubular member, in the region of the distal tip. In use, the inner tubular member and outer tubular member are in physical contact as a bearing surface in the distal tip region.

The coating was considered to be on the “soft” side of its potential spectrum, i.e. approx. 1,500 Vickers (14 GPa). The blade was a Smith & Nephew 4.5 mm Full Radius REF. 7205306, although the intention is to use this coating on all sizes and types of blades and burrs.

In the areas where there is no intentional contact between the inner and the outer blades, the gap between them could be as much as 0.25 mm.

INCORPORATION BY REFERENCE

All patents, published patent applications and other references disclosed herein are hereby expressly incorporated by reference in their entireties by reference.

EQUIVALENTS