The present invention relates to a method and apparatus for providing a soft-tissue transplant to a receiving bone and, more particularly, to a method and apparatus for providing a medial ulnar collateral ligament transplant graft to an ulna.
Injuries to the medial ulnar collateral ligament (MUCL) are not uncommon. Classically, these injuries are seen in the overhead-throwing athlete. Many injuries to the MUCL may be treated nonoperatively with good results. A considerable subset of athletes may require operative reconstruction of the anterior band of the MUCL, though, if they are unable to return to their pre-injury level of function following conservative management.
The MUCL is the major soft tissue restraint to valgus stress of the elbow from 30 to 120 degrees flexion. This ligament serves an integral function in overhead-throwing athletes who experience repeated valgus loads across the elbow. The anterior band is the key anatomic component of the MUCL that resists valgus stress during the throwing motion.
Current surgical reconstructive techniques are designed to address the anterior band of the MUCL. The goals of surgery are to restore the normal biomechanics and kinematics of the elbow joint. While some surgeons have presented good to excellent long term results in over 90 percent of athletes with surgical reconstruction, other authors have been unable to reproduce these results and have lower success rates. A thorough understanding of the anatomy of the medial ulnar collateral ligament is critical for successful reconstruction of the MUCL. The soft tissue anatomy of the medial ulnar collateral ligament ulnar attachment has previously been described. However, the length of the ulnar attachment of the ligament was not described. No study describing the soft-tissue, osseous, and radiographic anatomy of the MUCL ulnar footprint is known to the inventors at this time, who hypothesize that the MUCL has a long soft tissue attachment on the proximal aspect of the ulna and that there is a consistent osseous ridge in this location that corresponds to the attachment of the anterior band of the MUCL.
In an embodiment of the present invention, a method of providing a soft-tissue transplant to a receiving bone is described. A transplant graft is provided, comprising an elongated soft tissue, having first and second soft tissue ends longitudinally separated by a soft tissue body, and a bone block directly connected with the first soft tissue end. The bone block and soft tissue have been integrally formed as a unitary whole. An anchor cavity is machined in the receiving bone. The anchor cavity is shaped to substantially accept the bone block in a mating relationship. A majority of a volume of the bone block is placed in the anchor cavity. The bone block is fastened within the anchor cavity.
In an embodiment of the present invention, a system for providing a soft-tissue transplant to a receiving bone is provided. A transplant graft comprises an elongated soft tissue, having first and second soft tissue ends longitudinally separated by a soft tissue body, and a bone block directly connected with the first soft tissue end. The bone block and soft tissue have been integrally formed as a unitary whole. An anchor cavity is provided in the receiving bone. The anchor cavity is shaped to substantially accept the bone block in a mating relationship. A majority of a volume of the bone block is placed in the anchor cavity and the bone block is fastened to the receiving bone to place the soft tissue in a predetermined connected relationship with the receiving bone.
In an embodiment of the present invention, a method of providing a medial ulnar collateral ligament transplant graft to an ulna is provided. A transplant graft comprising an elongated ligament is provided, having first and second ligament ends longitudinally separated by a ligament body, and a bone block directly connected with the first ligament end. The bone block and ligament have been integrally formed as a unitary whole. An anchor cavity is machined in the ulna. The anchor cavity is shaped to substantially accept the bone block in a mating relationship. A majority of a volume of the bone block is placed in the anchor cavity. The bone block is fastened within the anchor cavity.
For a better understanding of the invention, reference may be made to the accompanying drawings, in which:
The patient tissue is shown and described herein at least as an elbow joint and the soft-tissue transplant is shown and described herein at least as a medial ulnar collateral ligament (MUCL), but the patient tissue and corresponding soft-tissue transplant could be any desired types such as, but not limited to, those used in hip joints, shoulder joints, knee joints, ankle joints, phalangeal joints, metatarsal joints, spinal structures, long bones (e.g., fracture sites), or any other suitable patient tissue use environment for the present invention. The below description presumes that the system, apparatus, and method described is being used in conjunction with a surgical procedure (namely, an at-least-partial MUCL replacement surgery), but the system(s), apparatus, and method(s) described may be used in any desired manner and for any desired purpose without harm to the present invention.
In accordance with the present invention,
The transplant graft 310 is shown in
Alternatively, and particularly when the transplant graft 310 is at least partially manufactured, rather than simply harvested from a native donor tissue, the bone block 320, soft tissue 312, and/or any components of the transplant graft could be separate during at least a portion of the manufacturing process, but could be combined during that process to become a unitary whole by the time manufacture is complete. Regardless of the manner in which such is provided, it may be desirable, for some embodiments of the present invention, for the bone block 320 and soft tissue 312 to be attached together in at least a semi-permanent manner, such that one of these structures would have to be cut or broken to separate them.
The transplant graft 310 may be at least partially made of any suitable material or combination of materials, including but not limited to bone, soft tissue, plastics, metals, composite materials, shape-memory materials, elastic materials, woven materials, extruded materials, and/or any other suitable manmade or nature-provided material(s).
The transplant graft 310, and components thereof, may have any suitable dimensions. For example, for an MUCL replacement, the soft tissue 312 may be in the range of about 30-50 mm long, more particularly about 40 mm, and about 6-10 mm wide, more particularly about 8 mm. Likewise, the bone block 320 may be in the range of about 10-30 mm long, more particularly about 20 mm, and about 3-9 mm wide, more particularly about 5 mm. Optionally, and as shown in
The bone block 320 or another portion of the transplant graft 310 may include one or more fastener holes 322 having any desired placement, shape, size, or other physical characteristics. These fastener holes 322 may be used to aid in attaching the transplant graft 310 to an anchor cavity of the receiving bone, as will be discussed below.
Operation of the cavity template 424 is shown in
Once the cavity template 424 has been placed and secured as desired with respect to the receiving bone, as shown in
It is also contemplated that the material-removal tool(s) 532 and/or the surrounded volume 428 could be designed and/or chosen to have corresponding dimensions for efficient machining. For example, the surrounded volume 428 could be shaped/sized such that a single one-way pass, or a single circuit, of the material-removal tool 532 within the cavity template 424 will cause the removal of all of the desired material, thus obviating the need for the user to go back and “clean up” kerf or other undesired extra material in the anchor cavity 534.
When the anchor cavity 534 has been machined as desired, the cavity template 424 can be removed from the receiving bone and either cleaned/prepared for reuse or disposed of. Removal of the cavity template 424 leaves the receiving bone (ulna 104) and anchor cavity 534 in a condition to facilitate further steps of the inventive system, as shown schematically in
Stated differently, the bone block 320 could have a graft form factor, and the cavity template 424 could embody at least a portion of the graft form factor which, when the cavity template is used with an appropriate material-removal tool 532, correlates at least one dimension of the resulting anchor cavity with the graft form factor. As an example, if the bone block 320 has a graft form factor with a width of 6 mm, the cavity template 424 could have a width of 6.2 mm or otherwise guide the material-removal tool 532 to create an anchor cavity 534 with a width of 6.2 mm. Accordingly, this example anchor cavity 534 would have a width configured to closely accept the bone block 320 therein, with clearance of 0.1 mm on either side of the width of the bone block. For many applications of the present invention, the user will want the anchor cavity 534 to be slightly larger than the bone block 320, for ease of insertion. However, it is contemplated that exactly matching, or even slightly smaller, dimensions of the anchor cavity 534 as compared to the bone block 320 may facilitate a desired friction- or interference-fit of the bone block 320 within the anchor cavity 534 for some applications of the present invention. It is also contemplated that the components making up the system disclosed herein may be designed with correlated relative dimensions chosen for a desired end result (e.g., to allow for dimensional tolerances or slight inaccuracies in measurements), rather than requiring the relative dimensions to be identical among the various components. Optionally, additional cavities, holes, tunnels, channels, protrusions, or other features may be machined into or provided to the receiving bone (ulna 104) or bone block 320 during preparation of these structures.
Once the anchor cavity 534 has been machined and otherwise prepared as desired, at least a portion of the bone block 320 may be placed in the anchor cavity. For example, a majority of the volume of the bone block 320 may be inserted into the anchor cavity 534 such that a relatively small amount of the bone block protrudes above the surrounding receiving bone surface. It is also contemplated that the anchor cavity 534 could have a depth chosen such that the bone block 320 is completely retracted into the anchor cavity, flush with or even below the surrounding receiving bone surface.
Optionally, a portion of the bone block 320 may protrude from the anchor cavity 534 in an asymmetrical or canted manner, such that the end of the bone block having the attached soft tissue 312 is substantially above the surface of the surrounding receiving bone, but the opposite end of the bone block is substantially flush with or even recessed below the surrounding receiving bone surface. When such a “ramp-like” anchor cavity 534 profile is desired, the sidewall 426 of the cavity template 424 may be shaped to echo the desired anchor cavity bottom slant and thus provide a variable depth-stop function during the machining process
The bone block 320, once placed in the anchor cavity 534 as desired, is then fastened within the anchor cavity. This fastening may be accomplished in any desired manner. For example, an adhesive substance (e.g., bone cement or the like) may be used to adhere the bone block 320 within the anchor cavity 534. As another example, at least one penetrating fastener (not shown) may be passed through at least a portion of the bone block 320 and into the receiving bone. This latter example may be particularly applicable when the bone block 320 includes at least one fastener hole 322, though the bone block could also or instead be directly penetrated by a fastener without the benefit of a previously provided fastener hole. Other examples of suitable fasteners include, but are not limited to, bone screws (cannulated and/or solid), with or without washers; suture anchors (screw-in and tap-in types); interference screws; and suspensory fixation devices.
Once the transplant graft 310 has been fastened into place as desired (such as through the fastening of the bone block 320 in the anchor cavity 534), the soft tissue 312—and particularly the first soft tissue end 314—will have achieved a predetermined connected relationship with the receiving bone, such as with the ulna 104 shown in
In
Use of the tool guide 1040 with a hole-forming material-removal tool 532 (e.g., a drill or circular reamer) is shown in the sequence of
Because of the spacing of the three lobes of the guiding aperture 1142, the series of three holes correspondingly machined by the material-removal tool 532 will extend contiguously in an overlapping relationship, as shown in
Optionally, the bone block 320 could be machined for mating acceptance by the intermediate cavity 1644—if so, the intermediate cavity can be considered to serve as an anchor cavity 534. However, for many applications of the present invention, further modifications will be made to the intermediate cavity 1644 before the bone block 320 is accepted. Turning to
As can be seen in the Figures, manipulation of the material-removal tool 532 of
While aspects of the present invention have been particularly shown and described with reference to the preferred embodiment above, it will be understood by those of ordinary skill in the art that various additional embodiments may be contemplated without departing from the spirit and scope of the present invention. For example, the specific methods described above for using the transplant graft 310 or other portions of the system are merely illustrative; one of ordinary skill in the art could readily determine any number of tools, sequences of steps, or other means/options for placing the above-described apparatus, or components thereof, into positions substantively similar to those shown and described herein. Radiopaque markers could be placed in association with any of the described structures and components as desired. Any of the described structures and components could be integrally formed as a single unitary or monolithic piece or made up of separate sub-components, with either of these formations involving any suitable stock or bespoke components and/or any suitable material or combinations of materials; however, the chosen material(s) should be biocompatible for many applications of the present invention. The mating relationships formed between the described structures need not keep the entirety of each of the “mating” surfaces in direct contact with each other but could include spacers or holdaways for partial direct contact, a liner or other intermediate member for indirect contact, or could even be approximated with intervening space remaining therebetween and no contact. Though certain components described herein are shown as having specific geometric shapes, all structures of the present invention may have any suitable shapes, sizes, configurations, relative relationships, cross-sectional areas, or any other physical characteristics as desirable for a particular application of the present invention. The transplant graft 310 or other portions of the system may include a plurality of structures cooperatively forming any components thereof and temporarily or permanently attached together in such a manner as to permit relative motion (e.g., pivoting, sliding, or any other motion) therebetween as desired. While discrete fasteners are discussed herein, it is contemplated that fasteners connected to one another in any desired manner may also or instead be used with the present invention. A cavity template 424 is shown here as accepting a material-removal tool 532 into a central aperture thereof, but it is also contemplated that the cavity template could also or instead include “stencil”-type feature(s) around an outside of which the material-removal tool could be passed. During formation of the anchor cavity 534, any desired “finishing” work (e.g., cleaning up or smoothing the inner surfaces of the anchor cavity) may be performed, whether or not the cavity template 424 remains in place during those finishing tasks. A tool guide 1040 could be used with a cavity template 424 in parallel, as shown in the Figures, or the tool guide could instead be used on its own, optionally in series with a cavity template--in the latter arrangement, the tool guide could itself be considered a cavity template. Any structures or features described with reference to one embodiment or configuration of the present invention could be provided, singly or in combination with other structures or features, to any other embodiment or configuration, as it would be impractical to describe each of the embodiments and configurations discussed herein as having all of the options discussed with respect to all of the other embodiments and configurations. A device or method incorporating any of these features should be understood to fall under the scope of the present invention as determined based upon the claims below and any equivalents thereof.
Other aspects, objects, and advantages of the present invention can be obtained from a study of the drawings, the disclosure, and the appended claims.
This application claims priority from U.S. Provisional Application No. 61/679,817, filed 6 Aug. 2012, the subject matter of which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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61679817 | Aug 2012 | US |