Sheathed surgical saw blade with bearing

Abstract

A sheathed blade assembly (100) is used to minimize or prevent contact between a moving inner blade and an outer sheath. The assembly includes: an outer sheath (106) having a first portion (110) and a second portion (112) with an inner cavity (132) between the first portion and the second portion; an inner blade (108) movable within the inner cavity of the outer sheath; a first recess (150A) within a first surface (152) of the inner blade; and a first ball bearing (148) within the first recess. The first ball bearing creates a clearance between the first surface of the inner blade and the first portion of the outer sheath. The assembly may also include a second recess (150B) for a second ball bearing (148) within a second surface (154) of the inner blade. The second ball bearing creates a clearance between the second surface of the inner blade and the second portion of the outer sheath. The second recess is in a staggered configuration relative to the first recess.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 639,040, filed on March 6, 2018, and entitled “Sheathed Surgical Saw Blade and Bearings,” and U.S. Provisional Patent Application Serial No. 62 / 724,914, filed on August 30, 2018, and entitled “Sheathed Surgical Saw Blade with Bearings and Universal Saw Handpiece for Sheathed and Standard Blades,” the entire texts of which are incorporated herein by reference. Background Art 1. Technical Field

[0004] The present invention relates generally to surgical blade assemblies, and more particularly to a sheathed blade assembly having a clearance between an outer sheath and an inner blade to minimize wear.

[0005] 2. Related technical description

[0006] A sheathed surgical blade comprises a moving inner member (the blade) and an outer fixed member (the sheath). During use, contact between the moving and fixed components is unavoidable due to the cantilever forces applied to the assembly. Due to the high linear speed of the blade, when the blade contacts the fixed sheath, the assembly can become very hot and wear. Heating of the sheath and blade can lead to bone necrosis and injury to the patient or user. In addition, the wear caused by the blade contacting the sheath will generate metal particles that can fall into the surgical site.

[0007] By design, sheathed blade assemblies and unsheathed (standard) blades require different mechanisms to interface with the surgical saw handpiece, thus requiring different handpieces to drive one or the other blade. The need for two different saw handpieces (one to drive the sheathed blade assembly and one to drive the unsheathed blade) adds additional cost to the surgical facility and / or requires the selection of one blade option (sheathed or unsheathed).

[0008] Therefore, there is a need for a single surgical saw handpiece for driving a sheathed blade assembly as well as an unsheathed (standard) blade and a sheathed blade assembly that prevents or minimizes potential contact between the internal moving blade and the sheath.

[0009] Related Art Section Disclaimer Description: With respect to specific patents / publications / products discussed above in the Related Art Section Description or elsewhere in this disclosure, such discussion should not be considered an admission that the discussed patents / publications / products are prior art for patent law purposes. For example, some or all of the discussed patents / publications / products may not be sufficiently early in time, may not reflect subject matter that was developed early enough in time, and / or may not be sufficient to achieve prior art equivalents for patent law purposes. With respect to specific patents / publications / products discussed above in the Related Art Section Description and / or throughout the application, their descriptions / disclosures are incorporated herein by reference in their respective entireties. Summary of the invention

[0010] The present invention relates to a single surgical saw that will drive a sheathed blade assembly as well as an unsheathed (standard) blade and a sheathed blade that prevents potential contact between a moving inner blade and an outer sheath. According to one aspect, the sheathed blade assembly includes: an outer sheath having a top portion and a bottom portion with an inner cavity between the top portion and the bottom portion; an inner blade movable within the inner cavity of the outer sheath; and at least one ball bearing within the inner cavity of the outer sheath. The ball bearing creates a clearance between the inner blade and at least one of the top portion and the bottom portion of the outer sheath.

[0011] According to another aspect, the sheathed blade assembly includes an outer sheath having a first portion and a second portion with an inner cavity between the first portion and the second portion; an inner blade movable within the inner cavity of the outer sheath; a first recess within a first surface of the inner blade; and a first ball bearing within the first recess. The first ball bearing creates a clearance between the first surface of the inner blade and the first portion of the outer sheath.

[0012] According to another aspect, the present invention is a surgical saw. The surgical saw includes a saw head, the saw head including a chuck having an opening, the opening being configured to receive a movable blade. The blade is removably connected within the chuck. A handpiece is connected to the saw head, and the handpiece has a drive mechanism to move the blade.

[0013] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] One or more aspects of the present invention are particularly pointed out and clearly claimed as examples in the claims at the end of the specification. The foregoing and other objects, features and advantages of the present invention will become apparent from the following description in conjunction with the accompanying drawings, in which:

[0015] Figure 1 is a top perspective schematic diagram of a sheathed blade assembly according to one embodiment;

[0016] Figure 2 is an exploded perspective schematic diagram of a sheathed blade assembly according to one embodiment;

[0017] Figure 3 is a distal schematic view of a sheathed blade assembly according to one embodiment;

[0018] Figure 4 is a schematic side view of a sheathed blade assembly according to one embodiment;

[0019] Figure 5 is a top perspective schematic diagram of a sheathed blade assembly according to an alternative embodiment;

[0020] Figure 6 is an exploded perspective schematic diagram of a sheathed blade assembly according to an alternative embodiment;

[0021] Figure 7 is a schematic side perspective view of a universal saw head according to one embodiment;

[0022] Figure 8 is a side perspective schematic diagram of a sheathed blade assembly connected to a universal saw head according to one embodiment;

[0023] Fig. 9 is a side perspective schematic diagram of an unsheathed blade connected to a universal saw head according to an alternative embodiment; and

[0024] Fig.10 is connected to Figure 8 Schematic diagram of an exploded view of a blade assembly with a sheath of a universal saw head. DETAILED DESCRIPTION

[0025] The various aspects of the present invention and certain features, advantages and details thereof are explained more fully below with reference to the non-limiting examples shown in the accompanying drawings. The description of known structures is omitted so as not to unnecessarily obscure the present invention in detail. However, it should be understood that the detailed description and specific non-limiting examples, although indicating aspects of the present invention, are given only in an illustrative manner, rather than in a limiting manner. In light of the present disclosure, various substitutions, modifications, additions and / or arrangements within the spirit and / or scope of the basic concepts of the present invention will be apparent to those skilled in the art.

[0026] Referring now to the drawings, wherein like reference numerals refer to like parts throughout, Figure 1 A top perspective schematic diagram of a sheathed blade assembly 100 according to one embodiment is shown. The sheathed blade assembly 100 extends from a proximal end 102 to a distal end 104. As shown in the depicted embodiment, the sheathed blade assembly 100 includes a fixed outer sheath 106 and a movable inner blade 108 extending from the fixed outer sheath.

[0027] Now go to Figure 2 , shows an exploded perspective schematic diagram of a sheathed blade assembly 100 according to one embodiment. In the depicted embodiment, the sheathed blade assembly 100 includes an outer sheath 106 having two parts, a top part 110 and a bottom part 112. The top part 110 and the bottom part 112 are constructed of a metal such as stainless steel. Figure 2 As shown, the top portion 110 is an elongated rectangular plate. In the depicted embodiment, the top portion 110 has a straight proximal edge 114 and a curved distal edge 116. The bottom portion 112 is also an elongated rectangular plate with a straight proximal edge 118 and a curved distal edge 120. The bottom portion 112 also includes a distal end 122 with a circular hole 124. In the depicted embodiment, the distal end 122 of the bottom portion 112 includes a pair of arms 126 (or prongs) extending therefrom. The arms 126 extend toward each other but do not intersect, thereby forming a gap 128 between them. The gap 128 extends into the circular hole 124, as shown.

[0028] Still reference Figure 2 , the outer sheath 106 also includes a track 130 extending along the bottom portion 112 between the straight proximal edge 118 and the curved distal edge 120. The track 130 defines an interior cavity 132 between the top portion 110 and the bottom portion 112 of the outer sheath 106 within the sheathed blade assembly 100. The interior cavity 132 is sized and configured to fit and accommodate the inner blade 108.

[0029] like Figure 2 As shown, the inner blade 108 includes a proximal cutting end 134 and a distal connecting end 136 (also referred to as a "hub" 164). In the depicted embodiment, the inner blade 108 is elongated and tapered, narrowing toward the proximal cutting end 134. The proximal cutting end 134 of the inner blade 108 includes a head 138 having a plurality of cutting teeth 140. Figure 2In the illustrated embodiment, the head 138 of the proximal cutting end 134 is trapezoidal in shape, with its width increasing in the proximal direction. The distal connecting end 136 includes a disk 142 having a plurality of slots 144 and an opening 146 extending therethrough. The disk 142 is sized and configured to fit within the aperture 124 in the distal end 122 of the base portion 112. In addition, the opening 146 in the disk 142 is positioned so that it is aligned with the gap 128 in the distal end 122 of the base portion 112. The purpose of the distal connecting end 136 of the inner blade 108 and the distal end 122 of the base portion 112 is to facilitate connection of the sheathed blade assembly 100 to the saw head 160 ( Figure 7 ).

[0030] Likewise Figure 2 As shown, the sheathed blade assembly 100 also includes one or more ball bearings 148 between the top portion 110 of the outer sheath 106 and the inner blade 108 and between the bottom portion 112 of the outer sheath 106 and the inner blade 108. The ball bearings 148 are disposed or positioned on both sides of the inner blade 108 and roll relative to the inner blade 108 and the top portion 110 and the bottom portion 112 of the outer sheath 106. Thus, the ball bearings 148 allow the inner blade 108 to move and minimize contact between the inner blade 108 and the outer sheath 106. The ball bearings 148 may be embedded in blind holes or slots (not shown) in the top portion 110 and the bottom portion 112 of the inner blade 108 or the outer sheath 106. The ball bearings 148 protrude beyond the surface of the inner blade 108 or the outer sheath 106 to maintain a gap between the inner blade 108 and the outer sheath 106.

[0031] Reference now Figure 3 and Figure 4 , showing schematic distal and side views of a sheathed blade assembly 100 according to one embodiment. Figure 3 The proximal end 102 of the sheathed blade assembly 100 is shown. In the depicted embodiment, the inner blade 108 is shown positioned within the lumen 132 of the outer sheath 106 (between the top portion 110 and the bottom portion 112). Figure 3 As shown, the ball bearing 148 is positioned within a pocket 150 in a top surface 152 of the inner blade 108 .

[0032] Figure 4 A side view of the sheathed blade assembly 100 is shown. In the depicted embodiment, the inner blade 108 is positioned within the lumen 132 of the outer sheath 106. Figure 4The inner blade 108 shown has two dimples 150A, 150B, one dimple 150A in the top surface 152 of the inner blade 108 and one dimple 150B in the bottom surface 154 of the inner blade 108, wherein the ball bearing 148 is positioned in the dimples 150A, 150B. In the depicted embodiment, the two dimples 150A, 150B are staggered so that one dimple 150A is distal to the proximal cutting end 134 of the inner blade 108 compared to the other dimple 150B. Although the size and configuration of the ball bearing 148 can be designed so that it fits in the dimples 150A, 150B, the blade assembly 100 with the sheath does not require the dimples 150A, 150B. The ball bearing 148 can be limited by the size of the outer sheath 106 and the width of the inner blade 108 within the outer sheath 106. The staggered configuration of the ball bearings 148 provides clearance between the inner blade 108 and the outer sheath 106, greatly reducing friction within the assembly, thereby reducing heat, wear and metal particle generation. The clearance also allows fluid to lubricate the moving parts of the sheathed blade assembly 100.

[0033] Now go to Figure 5 and Figure 6 , shows a schematic top perspective view and an exploded perspective view of a sheathed blade assembly 100 according to an alternative embodiment. Figure 5 and Figure 6 In the illustrated alternative embodiment of the sheathed blade assembly 100, the outer sheath 106 includes a plurality of cutouts 146 (i.e., holes or openings). Figure 5 As shown, the top portion 110 of the outer sheath 106 includes three trapezoidal or triangular shaped cutouts 156A extending therethrough. However, any number of cutouts 156A of any shape or configuration may be used.

[0034] exist Figure 6106 , the bottom portion 112 of the outer sheath 106 also includes a plurality of cutouts 156B (i.e., holes or openings) extending therethrough. The bottom portion 112 of the outer sheath 106 also includes three trapezoidal or triangular cutouts 156B extending therethrough (although any number of cutouts 156B of any shape or configuration may also be used). In the depicted embodiment, the cutouts 156B in the bottom portion 112 of the outer sheath 106 are aligned with the cutouts 156A in the top portion 110 of the outer sheath 106. The cutouts 156A, 156B reduce the contact surface area between the inner blade 108 and the outer sheath 106 and allow fluid from the surgical site to lubricate the moving parts. Thus, the cutouts 156A, 156B reduce friction and wear within the sheathed blade assembly 100, thereby reducing heat and metal particle generation in the sheathed blade assembly 100. To further reduce friction, wear, and heat, any surfaces of the inner blade 108 and outer sheath 106 may also include a coating 158, such as a physical vapor deposition (PVD) coating, a diamond-like carbon coating, and / or a dry lubricating coating, such as tungsten disulfide.

[0035] Reference now Figure 7 , shows a side perspective schematic diagram of a universal saw head 160 according to one embodiment. In the depicted embodiment, the saw head 160 includes a blade assembly 100 ( Figure 1 ) and unsheathed (standard) blade 200. When using a sheathed blade 100, such as Figure 1 to Figure 2 As shown, the chuck 162 secures the outer sheath 106 to keep it stationary while engaging and driving the inner blade 108 using the hub 164 of the inner blade 108. When an unsheathed blade 200 is used, the saw head 160 engages and drives the unsheathed blade 200 using the hub (not shown) of the unsheathed blade 200 because it has the same design as the sheathed blade assembly 100 ( Figure 2 ) hub 164, while the chuck 162 provides sufficient clearance so that the standard blade 200 will not contact any mechanism associated with the fixed outer sheath 106. Since the saw head 160 can accommodate the sheathed blade assembly 100 ( Figure 1 ) and unsheathed (standard) blades 200, eliminating the need for two different types of saw heads, reducing procurement costs and inventory. It can also improve logistics for hospitals and surgical centers. Figure 7 As shown, the single universal saw head 160 also provides a user (eg, a surgeon) with greater flexibility in selecting blade types for various surgical resections during orthopedic surgery.

[0036] Briefly go to Figure 8 and Fig. 9, respectively, show side perspective schematic diagrams of a sheathed blade assembly 100 and an unsheathed blade 200 connected to a universal saw head 160. Figure 8 and Fig. 9 As shown in both, Figure 7 The universal saw head 160 may be attached to a handpiece 166. The handpiece 166 may be any handpiece having a drive mechanism, such as a battery powered handpiece or a pneumatic handpiece.

[0037] exist Figure 8 In an embodiment using a sheathed blade assembly 100, the cartridge 162 is disposed at the distal end 122 ( Figure 2 ) at the gripping arm 126. In particular, Fig.10 As shown, one or more raised areas 172 on the collet 162 clamp (or otherwise grip) the outer sheath 106 of the sheathed blade assembly 100 to hold it stationary, while the inner blade 108 essentially floats within the outer sheath 106. Thus, the collet 162 is connected to the fixed outer sheath 106 without contacting the movable inner blade 108, as shown in FIG. Fig.10 shown.

[0038] When using an unsheathed (standard) blade 200, such as Fig. 9 As shown, the cartridge 162 is connected to the hub of the unsheathed blade 200 (similar to the hub 164 ( Figure 2 )), but a clearance 168 is left between the blade 200 and the chuck 162 to prevent contact, heating and damage. Fig. 9 The amount of clearance 168 in the cartridge 162 may be created by a groove 174 in the cartridge 162, such as Fig.10 The groove 174 provides a clearance amount 168 ( Fig. 9 ).

[0039] Fig.10 Various other components of the collet 162 and saw head 160 are also shown. In the depicted embodiment, the sheathed blade assembly 100 is attached to the collet 162 (and saw head 160) via a cover 176 and a conventional connector 178. In the depicted embodiment, the connector 178 is attached to the cover 176 and extends through the hub 164 and collet 162 of the sheathed blade assembly 100. Fig.10 As shown, the saw head 160 includes a drive hub 180. The drive hub 180 is a movable component of the saw head 160. When the fixed outer sheath 106 is clamped by the raised area 172 of the chuck 162, the inner blade 180 is driven, moved or otherwise actuated by the drive hub 180, which is connected to a drive mechanism (not shown) in the handpiece 166.

[0040] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0041] Although various embodiments have been described and shown herein, a person of ordinary skill in the art will readily conceive of various other devices and / or structures for performing functions and / or obtaining results and / or one or more of the advantages described herein, and each of such variations and / or modifications is considered to be within the scope of the embodiments described herein. More generally, it will be readily understood by those skilled in the art that all parameters, dimensions, materials, and configurations described herein are exemplary, and that actual parameters, dimensions, materials, and / or configurations will depend on the teachings of the present invention for one or more specific applications thereof. Using only routine experiments, those skilled in the art will recognize or be able to determine many equivalents of the specific embodiments described herein. Therefore, it should be understood that the foregoing embodiments are given only by way of example, and within the scope of the appended claims and their equivalents, embodiments may be practiced in a manner different from that specifically described and protected by the claims. The embodiments of the present disclosure relate to each individual feature, system, article, material, kit, and / or method described herein. In addition, if these features, systems, articles, materials, kits, and / or methods are not mutually contradictory, any combination of two or more such features, systems, articles, materials, kits, and / or methods is also included within the scope of the present disclosure.

[0042] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are also intended to include plural forms. It should also be understood that the terms "comprise" (and any form of "comprise", such as "comprises" and "comprising"), "have" (and any form of "have", such as "has" and "having"), "include" (and any form of "include", such as "includes" and "including"), and "contain" (and any form of "contain", such as "contains" and "containing") are open-ended copulas. Therefore, "including", "having", "including" or "containing" a method or device of one or more steps or elements. Likewise, a method step or an apparatus element that "comprises," "has," "includes," or "contains" one or more features has those one or more features, but is not limited to having only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed.

[0043] All means or steps in the following claims plus corresponding structures, materials, operations, and equivalents of functional elements, if any, are intended to include any structure, material, or operation for performing a function in combination with other claimed elements as specifically claimed. The description of the present invention has been given for the purpose of illustration and description, but the description is not exhaustive or limits the invention to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiments are selected and described in order to best explain the principles and practical applications of one or more aspects of the invention, and to enable others of ordinary skill in the art to understand one or more aspects of the invention for various embodiments with various modifications suitable for the specific purposes contemplated.

Claims

1. A blade assembly with a sheath, include: an outer sheath having a top portion and a bottom portion with an inner cavity therebetween; an inner blade movable within the lumen of the outer sheath; a ball bearing within the inner cavity of the outer sheath; Wherein the ball bearing creates an amount of clearance between the inner blade and at least one of the top portion and the bottom portion of the outer sheath, the ball bearing being positioned within a recess in a top surface or a bottom surface of the inner blade.

2. The assembly of claim 1, wherein the outer sheath is fixed relative to the movable inner blade.

3. The assembly of claim 1, wherein the inner blade tapers toward a proximal cutting end.

4. The assembly of claim 3, further comprising a head at the proximal cutting end of the inner blade, the head having a plurality of cutting teeth extending therefrom.

5. The assembly of claim 4, wherein the width of the head increases proximally.

6. The assembly of claim 1 wherein the inner blade has a distal connection end comprising a disk having a plurality of apertures extending therethrough.

7. The assembly of claim 6 further comprising an opening extending into said disk.

8. The assembly of claim 7, wherein the bottom portion of the outer sheath includes a distal end having an opening that aligns with the opening in the disk.

9. A blade assembly with a sheath, include: an outer sheath having a first portion and a second portion with an inner lumen therebetween; an inner blade movable within the lumen of the outer sheath; a first recess in a first surface of the inner blade; a first ball bearing, the first ball bearing being in the first recess; wherein the first ball bearing creates a clearance amount between the first surface of the inner blade and the first portion of the outer sheath, The assembly further includes a second recess in a second surface of the inner blade, the second surface being opposite the first surface, The assembly also includes a second ball bearing within the second pocket.

10. The assembly of claim 9, wherein the second ball bearing creates a clearance volume between the second surface of the inner blade and the second portion of the outer sheath.

11. The assembly of claim 9, wherein the second dimples are in a staggered configuration relative to the first dimples.

12. The assembly of claim 9, further comprising a first plurality of cutouts extending through the first portion.

13. The assembly of claim 12, further comprising a second plurality of cutouts extending through the second portion, the second plurality of cutouts being aligned with the first plurality of cutouts.

14. The assembly of claim 9, further comprising a coating on at least one of the inner blade and the outer sheath, the coating consisting of at least one of a physical vapor deposition coating, a carbon coating, and a dry lubrication coating.

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