Not Applicable.
1. Field of the Invention
The invention relates generally to devices and methods for orthopedic surgery. More particularly, the invention relates to devices and method for aligning a guide pin for re-surfacing the ball portion of a ball and socket joint.
2. Background of the Invention
Total hip replacement, also referred to as hip arthroplasty, is a surgical procedure in which the hip joint is replaced by a prosthetic implant. Hip joint replacement surgery is typically conducted to relieve arthritis or to repair severe joint damage resulting from fracture. Hip resurfacing arthroplasty is a type of hip replacement that replaces the surface of the joint but removes far less bone than the traditional total hip replacement. Since hip resurfacing removes less bone, it may be particularly suited for younger patients that are expected to need a second, or revision, hip replacement surgery as they grow older and wear-out or out-grow the original artificial hip replacement.
Although hip resurfacing arthroplasty removes less bone, it is a technically more difficult operation with a higher complication rate then routine total hip replacement. One potential complication is femoral neck fracture, which is generally influenced by four factors including varus placement of the femoral component, notching during surgery, Body Mass Index (BMI), and gender. Although BMI and gender of a given patient cannot be controlled by the surgeon, varus placement of the femoral component and notching during surgery may be impacted by the surgeon's performance and procedure. In particular, proper placement of the guide pin to resurface the femoral head can reduce notching and improve varus placement of the femoral component.
Optimal placement of the guide pin depends on the anteversion/retroversion (generally “version”) angular orientation of the guide pin relative to the ball portion of the femoral neck, the varus/valgus orientation of the guide pin relative to the ball portion of the femoral neck, and the intersection of the femoral neck central axis with the surface of the ball portion of the femoral neck. As is known in the art, varus/valgus alignment generally refers to the angular orientation of the femur longitudinal axis measured in the coronal or frontal plane, and femoral version generally refers to the angular orientation of the femoral neck measured in the transverse plane. Referring briefly to
Accordingly, there is a need for devices and methods that enable a surgeon to properly position a guide pin for joint resurfacing procedures. Such devices and methods would be particularly well received if they provided a relatively simple, cost effective approach to position the guide pin without requiring simultaneous varus/valgus alignment, the entry point of the guide pin, and anteversion/retroversion alignment.
These and other needs in the art are addressed in one embodiment by a drill guide for aligning a guide pin. In an embodiment, the drill guide comprises a base having a concave inner surface, an outer surface opposite the inner surface, and a central axis perpendicular to the inner surface. In addition, the drill guide comprises a drilling template extending axially from the outer surface of the base along the central axis and includes a plurality of through-bores extending completely through the drilling template to the inner surface of the base. Further, the drill guide comprises a first curved member extending along a central longitudinal axis from a fixed end integral with the base to a free end distal the base and a second curved member extending along a central longitudinal axis from a fixed end integral with the base to a free end distal the base. The first curved member and the second curved member are angularly spaced about 180 degrees apart relative to the central axis and include an elongate locking slot aligned with the central longitudinal axis.
These and other needs in the art are addressed in another embodiment by a drill guide for aligning a guide pin. In an embodiment, the drill guide comprises a base having a concave inner surface, an outer surface opposite the inner surface, and a central axis perpendicular to the inner surface. In addition, the drill guide comprises a drilling template centered on the upper surface of the base and includes a plurality of through-bores extending completely through the drilling template to the inner surface of the base. Further, the drill guide comprises a plurality of curved members extending along a central longitudinal axis from a fixed end integral with the base to a free end distal the base and angularly spaced relative to the central axis. Each curved member includes an elongate locking slot aligned with the central longitudinal axis.
These and other needs in the art are addressed in another embodiment by a method for aligning a guide pin for re-surfacing a joint. In an embodiment, the method comprises providing a drill guide. The drill guide includes a base having a curved inner surface, an outer surface opposite the inner surface, and a central axis perpendicular to the inner surface. In addition, the drill guide includes a plurality of curved members extending from the base and angularly spaced relative to the central axis. Each curved member extends along a central longitudinal axis from a first end coupled to the base to a second end distal the base. Further, the drill guide includes a drilling template centered on the upper surface of the base. The drilling template includes a plurality of through-bores. Each curved member includes an elongate locking slot positioned along the central longitudinal axis. In addition, the method comprises placing the drill guide over a ball portion of a ball and socket joint such that the inner surface of the base engages the ball portion. Further, the method comprises restricting the rotation of the drill guide relative to a first axis. Moreover, the method comprises restricting the rotation of the drill guide relative to a second axis orthogonal to the first axis.
Thus, embodiments described herein comprise a combination of features and advantages intended to address various shortcomings associated with certain prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, and by referring to the accompanying drawings.
The foregoing has outlined rather broadly certain features and technical advantages of the disclosed devices and methods in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
The following discussion is directed to various embodiments of the invention. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.
Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections. Further, the terms “radial” and “radially” may be used to described positions, movement, or distances perpendicular to a central axis or longitudinal, while the terms “axial” and “axially” may be used to describe positions, movement, or distances parallel to the central or longitudinal axis.
Referring now to
Base 112 has a partially spherical geometry including a convex upper or outer surface 114 and a concave lower or inner surface 116 substantially parallel with outer surface 114. Inner surface 116 may generally be described as being disposed on a reference sphere 108. A central axis 101 passes through the center of base 112 substantially perpendicular to inner and outer surfaces 114, 116. Still further, base 112 includes a plurality of locking through holes or bores 124, each locking hole 124 radially positioned between the outer radial periphery of base 112 and a drilling template 102 disposed at the center of base 112 (i.e., centered relative to central axis 101). In this embodiment, locking holes 124 are uniformly angularly spaced about 90 degrees apart about central axis 101. Further, each locking hole 124 is positioned in base 112 between each pair of curved members 104. In general, each locking hole 124 may have any suitable diameter, but is preferably has a diameter between about 2 mm and 6 mm. Locking holes 124 provide a means to restrict the movement and rotation of drill guide 100 relative to the ball portion on which it is disposed for resurfacing operations. In particular, a pin is disposed through one or more holes 124 and into positive engagement with the ball portion to restrict translational and rotational movement of drill guide 100 relative to the ball portion.
Referring still to
Drilling template 102 also includes a plurality of substantially parallel through-bores 103 extending from planar surface 118 of free end 102a to inner surface 116 of base 112. In this embodiment, each through-bore 103 is substantially parallel to central axis 101. However, in other embodiments one or more of the through-bores (e.g. through-bores 103) may be oriented at an acute angle relative to a central axis (e.g. central axis 101). Further, in this embodiment, each bore 103 is formed by a rigid, durable insert sleeve 105 intended to reduce and/or prevent damage to drilling template 102 during guide pin insertion operations. Sleeves 105 may comprise any suitable rigid, durable material including, without limitation, metals or metal alloys (e.g., stainless steel, aluminum, etc.), polymer (e.g., polyethylene), composite, or combinations thereof. Preferably, sleeve 105 comprises a rigid durable, low-friction polymer such as polyethylene.
In general, through-bores 103 may have any suitable diameter, spacing, and arrangement. However, each through-bore (e.g., through-bore 103) preferably has a diameter between about 1 mm and about 10 mm, more preferably between about 2 mm and 5 mm, and even more preferably between about 2 mm to about 3 mm. Further, the through-bores are preferably spaced less than or equal to about 2 mm apart measured by the least distance between the outer perimeters of two adjacent through-bores (e.g., through-bores 103). It should be appreciated that the spacing of the through-bores may be less than 0, in which case the outer perimeter of two adjacent through-bores may overlap or cross. In the embodiment shown in
During ball joint resurfacing, drill guide 100 is placed over the ball portion to be resurfaced and through-bores 103 provide a path for a guide pin to be inserted into the ball portion for the resurfacing procedures. Depending on a variety of factors including, without limitation, user preferences, bone structure and geometry, patient BMI, patient gender, and expected patient activities and associated loading, a specific through-bore 103 may be selected to optimize joint resurfacing geometry. In this manner, drilling template 102 allows alignment of a guide pin with an axis passing through the ball portion that may be offset or misaligned with the center of the ball portion itself. For example, the drilling template permits alignment of a guide pin with the central axis of the femoral neck (e.g., central axis 35 of femoral neck 30 previously described with reference to
Although drilling template 102 is shown and described as extending axially from base 102, in other embodiments, the drilling template (e.g., drilling template 102) may be flush with the outer surface of the base. In such embodiments, the drilling template does not extend from the outer surface of the base (e.g., outer surface 114 of base 112), and the through-bores of the drilling template (e.g., through-bores 103) extend from the outer surface of the base to the inner surface of the base (e.g., inner surface 116). Further, although drilling template 102 is integral with base 112 in the embodiment shown in
Referring still to
Each curved member 104 has a convex, partially spherical outer surface 114a, a concave, partially spherical inner surface 116a generally parallel with outer surface 114a and disposed on reference sphere 108 previously described. Outer surface 114a of each curved member 104 is contiguous with and continuously contoured with outer surface 114 of base 112. Likewise, inner surface 116a of each curved member 104 is contiguous with and continuously contoured with inner surface 116 of base 112. Since inner surface 116a of each curved member 104 and inner surface 116 of base 112 are each disposed on a common reference sphere 108, base 112 and curved members 104 form a partially spherical drill guide 100.
Referring still to
Referring still to
Drill guide 100 also includes a plurality of inspection slots 152, each aligned but axially spaced above one of locking slots 122 (relative to central longitudinal axis 109). In particular, each inspection slot 152 extends along central longitudinal axis 109 from the upper portion of curved member 104, across fixed end 104a, and into base 112. Although inspection slots 152 extend into base 112, each is radially spaced apart from drilling template 112 (relative to central axis 101). Each inspection slot 152 extends completely from outer surfaces 114, 114a to inner surfaces 116, 116a, thereby providing a means to view and inspect the ball portion and soft tissue disposed within drill guide 100.
Referring now to
Once drill guide 100 is sufficiently disposed on ball portion 32, one or more slot pins 126 are disposed through locking slots 122 of one pair of opposed curved members 104 and into positive engagement with ball portion 32, and one or more pins are disposed through locking slots 122 of the other pair of opposed curved members 104. As shown in
With the rotation of drill guide 100 restricted to two degrees (i.e., about axes 45, 55), the orientation of drill guide 100 is adjusted to achieve the desired position of drilling template 112 relative to ball portion 32. To reduce complexities of simultaneous adjustment of drill guide 100 about multiple axes (e.g., axes 45, 55), drill guide 100 is preferably initially rotated about first axis 45, followed by second axis 55, or vice versa. It should be appreciated that slot pins 126 slidingly engage locking slots 122, and thus, are permitted to slide through locking slots 122 as the orientation of drill guide 100 is adjusted about axes 45, 55. Once the desired rotation about axes 45, 55 and orientation of drill guide 100 and drilling template 112 is achieved, one or more hole pins 128 or other suitable securing means are inserted through one or more locking hole 124 and into positive engagement with ball portion 32, thereby completely restricting rotation of drill guide 100 and drilling template 112 about center 38.
With the position of drilling template 112 locked relative to ball portion 32, a guide pin 70 is advanced through one of the through-bores 103 for subsequent resurfacing operations. As previously described, an array of through-bores 103 are provided in drilling template 112. Consequently, to accommodate for any variation in the final orientation and locking of the drilling template 112 relative to ball portion 32, multiple through-bores 103, each providing a slightly different entry point is available to achieve the desired guide pin 70 orientation.
During placement of drill guide 100 on ball portion 102, pinning of drill guide 100 to ball portion 102, adjustment of drill guide 100 relative to ball portion 102, and locking of drill guide 100 relative to ball portion 32, inspection slots 152 may be utilized by the surgeon or user of device 100 to view ball portion 32 and associated soft tissue.
Referring now to
Two adjacent curved members 204 (i.e., two curved members angularly spaced 90 degrees apart relative to central axis 201) each include a depth of resection indication slot 250 disposed between an elongate locking slot 222 and a fixed end 204a, and oriented substantially perpendicular to locking slot 222. Further, the two adjacent curved members 204 including resection indication slots 250 each include an inspection slot 252 that is aligned with but axially spaced above one of locking slots 222 (relative to central longitudinal axis 109). However, unlike drill guide 100 previously described with reference to
Referring now to
Referring now to
Referring now to
Embodiments of drill guide 100, 200, 300, 500, and 600 may comprise any suitable material(s) including without limitation metals (e.g., stainless steel, titanium, etc.), non-metals (e.g., polymer, composites, etc.) or combinations thereof. The components of drill guide 100, 200, 300, 500, and 600 are preferably manufactured from a durable biocompatible material such as titanium, stainless steel, or polymers such as high density polyethylene. A polymeric drill guide 100, 200, 300, 500, and 600 offers the potential for relatively inexpensive material and manufacturing costs, thereby allowing for an economically feasible disposable drill guide 100, 200, 300, 500, and 600.
Moreover, the components of drill guide 100, 200, 300, 500, and 600 may be manufactured by any suitable methods. Examples of suitable methods include, without limitation, casting or molding, machining, laser cutting, electromechanical deposition (EMD), or combinations thereof. The components of drill guide 100, 200, 300, 500, and 600 may be assembled by any suitable method including without limitation welding, press fitting, or combinations thereof. Moreover, it is envisioned that various sizes of drill guide 100, 200, 300, 500, and 600 may be manufactured to accommodate different sized joints. For example, women and children may have different joint sizes than an adult male joint.
Although embodiments described herein were described for use in positioning a guide pin for resurfacing the ball portion of a hip ball and socket joint, in general, embodiments of drill guide 100, 200, 300, 500, and 600 may be sized and utilized to position a guide pin for resurfacing the ball portion of any ball and socket joint.
While embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings. The embodiments described and the examples provided herein are exemplary only, and are not intended to be limiting. Many variations and modifications of the embodiments disclosed herein are possible. Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims.
This application claims the benefit of U.S. provisional application Ser. No. 60/985,547, filed Nov. 5, 2007, and entitled “Joint Re-Surfacing Drill Guide”,” which is hereby incorporated herein by reference in its entirety.
Number | Date | Country | |
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60985547 | Nov 2007 | US |