Patent Application
20080103500
During spinal surgery to treat spinal disease, for example, to correct a spinal deformity or to treat degenerative disc disease, one or more spinal rods may be cut by the surgeon or operating room staff to a length suitable for the patient's anatomy and for the procedure being performed. Frequently, the cut end of the spinal rod may have sharp edges and/or burrs that pose a safety risk to the surgeon and the operating room staff. For example, the sharp edge or burrs of the rod may cut the surgical glove or skin of the surgeon thereby exposing the surgeon and the patient to blood borne pathogens. Accordingly, there is a need for an instrument that can smooth the edges of the end of a spinal rod.
Disclosed herein are instruments and methods for smoothing a portion of a spinal rod. In one exemplary embodiment, an instrument for smoothing an end of a spinal rod may include a housing having an opening sized and shaped to receive a spinal rod and a smoothing surface positioned within the housing and in communication with the opening. The smoothing surface may have one or more structures configured to engage a portion of the spinal rod and, upon relative rotation of the spinal rod to the smoothing surface, to smooth the portion of the spinal rod by removing material from the spinal rod.
In another exemplary embodiment, an instrument for smoothing an end of a spinal rod may include a cylindrical housing having a rod opening at a first end thereof and an approximately conical smoothing surface positioned within the housing and in communication with the rod opening. The smoothing surface may have one or more cutting blades configured to engage an end of the spinal rod and, upon relative rotation of the spinal rod to the smoothing surface, to smooth the end of the spinal rod by removing material from the spinal rod.
In a further exemplary embodiment, an instrument for smoothing an end of a spinal rod may include a cylindrical housing having a first rod opening at a first end thereof, a first shaft positioned in the housing, the first shaft having a first smoothing surface positioned at a first end of the first shaft, and a second shaft positioned in the housing, the second shaft having a second smoothing surface positioned at a first end of the second shaft. The first smoothing surface and the second smoothing surface may be positioned within the housing to receive an end of a spinal rod therebetween and in communication with the first rod opening. The first and second smoothing surfaces may have one or more cutting blades configured to engage the end of the spinal rod and, upon relative rotation of the spinal rod to the first and second smoothing surfaces, to smooth the end of the spinal rod by removing material from the spinal rod.
These and other features and advantages of the instrument and methods disclosed herein will be more fully understood by reference to the following detailed description in conjunction with the attached drawings in which like reference numerals refer to like elements through the different views. The drawings illustrate principles of the instruments and methods disclosed herein and, although not to scale, show relative dimensions.
Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the instruments and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the instruments and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.
The articles “a” and “an” are used herein to refer to one or to more than one (i.e. to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element.
The terms “comprise,” “include,” and “have,” and the derivatives thereof, are used herein interchangeably as comprehensive, open-ended terms. For example, use of “comprising,” “including,” or “having” means that whatever element is comprised, had, or included, is not the only element encompassed by the subject of the clause that contains the verb.
In the exemplary embodiment, the housing 12 of the instrument 10 is generally cylindrical in shape having a generally circular cross section, although, one skilled in the art will appreciate that other shapes, including rectilinear or oval, are possible. The housing has a first end 20 and a second end 22. The rod opening 14 is positioned in the first end 20 of the housing 12. An elongated bore 24 may be provided in the second end 22 and may extend along a portion of the housing to reduce the weight of the housing 12. The outer surface 26 may include texturing, grooves, or other surface features 28 to facilitate gripping of the housing during rod smoothing operations.
The smoothing surface 16 may have a size and shape to receive and engage a portion, for example, the end, of a spinal rod. In the exemplary embodiment, the smoothing surface 16 is approximately conical in shape and defines a rod receiving cavity having an approximately conical shape for receiving the spinal rod. In this manner, the smoothing surface 16 tapers from the rod opening 14 to the interior of the rod receiving cavity thereby allowing the smoothing surface to engage rods of varying diameters.
The smoothing surface 16 may include one or more structures 18 configured to engage and smooth a portion of a spinal rod. The structures 18 may be one or more cutting blades formed in the smoothing surface 16. The cutting blades may be edged, sharpened and/or peaked projections provided on the smoothing surface 16. In the exemplary embodiment, the structures 18 are formed be a plurality of arcuate, in cross section, slots 30 provided in the smoothing surface 16 whereby the edges of the slots 30 may engage and smooth a portion of the rod during rotation of the rod relative to the smoothing surface 16. The slots 30 may be spaced about the smoothing surface 16 and any number of slots 30, or other structures, may be provided. The smoothing surface 16 and the structures 18 may be manufactured from any material suitable for cutting, grinding, or otherwise smoothing a metal (e.g., stainless steel or titanium) spinal rod. Suitable materials include, but are not limited to, stainless steel and stone (e.g., a grinding stone).
In the exemplary embodiment, the instrument 10 may include a removable and replaceable cover 32 engagable with the first end 20 of the housing 12. The cover 32 includes a cover opening 34 aligned with the rod opening 14 upon engagement of the cover 32 to the housing 12. The cover 32 may have a size and shape complementary to the size and shape of the housing. In the exemplary embodiment, the cover 32 is generally cylindrical in shape and has an open first end 35 and a closed second end 36 with the cover opening 34 formed in the closed second end 36. The closed second end 36 is spaced apart from the rod opening 14 upon engagement of the cover 32 with the housing 12 providing a collecting space 40 for collecting shavings, debris, or other removed material during smoothing operations. Moreover, by spacing the second end 36, and, thus, the cover opening 34, from the rod opening 14, the cover 32 may operate to stabilize the rod during smoothing operations. The cover opening 34 may be sized and shaped to approximate the size and shape of the spinal rod to facilitate stabilization of the spinal rod during smoothing operations. For example, in the case of round spinal rods, the cover opening 34 may have a diameter approximate to standard sizes for round spinal rods, such as, for example, a rod diameter of approximately 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, or 6.35 mm. In the case of a 5.5 mm spinal rod, for example, the cover opening 32 may be 6.0 mm in diameter and in the case of a 6.35 mm spinal rod, for example, the cover opening 32 may be 6.85 mm in diameter. One skilled in the art will appreciate that the cover opening 34 is not limited to these sizes or a round shape.
The cover 32 may include a connection mechanism to permit selective connection of the cover 32 to the housing 12 of the instrument 10. In the illustrated embodiment, for example, the cover 32 includes internal threads 42 for engagement with external threads 44 of the first end of housing 12. In other embodiments, alternative connection mechanisms, for example a snap-fit connection, may be employed.
In certain exemplary embodiments, the instrument 10 may include additional removable and replaceable covers having cover openings of differing sizes and/or shapes. Such additional covers facilitate the use of one instrument 10 with rods of differing sizes and shapes.
The instrument 10 may be manufactured from metal, polymers, ceramics, or other material suitable for use in medical instruments. In one exemplary embodiment, the instrument 10 is manufactured from stainless steel.
In use, a portion of a spinal rod, e.g., an end of a spinal rod, may be inserted through the cover opening 34 and the rod opening 14 into engagement with the smoothing surface 16. By rotating the spinal rod relative to the smoothing surface 16, the rod is smoothed. In certain embodiments, the rod 12 may be rotated relative to the housing 12. In other embodiments, the housing 12 may be rotated relative to the rod. The housing 12 may be configured for connection to a rotary drive, e.g., a rotating shaft, of a power tool to facilitate rotation of the housing 12 relative to the spinal rod.
The housing 112, in the exemplary embodiment, includes a second end 122 having a second rod opening 124 formed therein for receiving a second spinal rod 200B. The second rod opening 124 may have a size and a shape distinct from the first rod opening 114. In the exemplary embodiment, for example, the first rod opening 114 may be sized to receive a round spinal rod 200A having a 6.35 mm diameter and the second rod opening 124 may be sized to receive a round spinal rod 200B having a 5.5 mm diameter. The first rod opening 114 and the second rod opening 124 may have a size approximate the size of the spinal rod to be received therein. For example, the first rod opening 114 has a diameter of 6.85 mm to receive a 6.35 mm spinal rod 200A and the second rod opening has a diameter of 6.0 to receive a 5.5 mm spinal rod 200B.
In the exemplary embodiment, the first shaft 150 may have a third smoothing surface 164 positioned at a second end 154 of the first shaft 150 and the second shaft 170 has a fourth smoothing surface 166 positioned at a second end 174 of the second shaft 170, the third smoothing surface 164 and the fourth smoothing surface 166 positioned within the housing 112 to receive an end of a second spinal rod 200B therebetween and in communication with the second rod opening 124. The third and fourth smoothing surfaces 164, 166 may have one or more cutting blades 118 configured to engage the end 202B of the spinal rod 200B and, upon relative rotation of the spinal rod 200B to the third and fourth smoothing surfaces 164, 166, to smooth the end 202B of the spinal rod 200B by removing material from the spinal rod 202B.
The first shaft 150 and the second shaft 170 may be fixed to the housing 112. In the exemplary embodiment, for example, the first and second shafts 150, 170 may be connected to the ends 120, 122 of the housing 112. In alternative embodiments, the first shaft 150 and/or the second shaft 170 may rotate about their respective longitudinal central axis relative to the housing 112. In certain embodiments, the first shaft 150 may be coupled to the second shaft 170 by one or more gears that permit the first and second shafts 150, 170 to rotate together. The first and second shafts 150, 170 may be connected to a rotating shaft, gear, or other device that is rotated by a motor, for example, the motor of a rotary power tool.
The smoothing surfaces 160, 162, 164, and 166 may be an approximately conical in shape or may otherwise taper from an end of the respective shaft toward the middle of the respective shaft. In this arrangement, the first smoothing surface 160 and the second smoothing surface 162 are positioned relative to one another to create an approximately conical cavity therebetween for receiving the end 202A of the spinal rod 200A. Likewise, the third smoothing surface 164 and the fourth smoothing surface 164 are positioned relative to one another to create an approximately conical cavity therebetween for receiving the end 202B of the spinal rod 200B.
While the instruments and methods of the present invention have been particularly shown and described with reference to the exemplary embodiments thereof, those of ordinary skill in the art will understand that various changes may be made in the form and details herein without departing from the spirit and scope of the present invention. Those of ordinary skill in the art will recognize or be able to ascertain many equivalents to the exemplary embodiments described specifically herein by using no more than routine experimentation. Such equivalents are intended to be encompassed by the scope of the present invention and the appended claims.
This application claims priority to U.S. Provisional Patent Application No. 60/863,690 filed Oct. 31, 2006, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60863690 | Oct 2006 | US |
