Patent Application
20100121325
This invention relates to the field of orthopedic implant devices, and more particularly, to a hybrid intramedullary fixation assembly comprising a screw and plate fixation assembly used for internal fixation of angled joints, bones and joint reinforcement, such as the bones in the foot.
Orthopedic implant devices, such as intramedullary nails, plates, rods and screws are often used to repair or reconstruct bones and joints affected by trauma, degeneration, injury, deformity and disease, such as injuries to the tarsometatarsal joint caused by accidents or falls or Charcot arthropathy caused by diabetes in some patients.
Injuries to the tarsometarsal joint occur in athletics, from minor twisting injuries when stepping unevenly, to more violent injuries that may occur in motor vehicle accidents or falls, while charcot arthropathy (or Charcot foot) is a destructive process affecting many regions including joints of the foot and ankle in diabetics. This condition causes bony fragmentation, dislocation, and fractures that eventually progresses to foot deformity, bony prominences, ulceration and instability of the foot. Charcot arthropathy can affect any joint in the body but is often seen in the feet affecting the metatarsal, tarsometatarsal and tarsal joints and frequently causes the foot to lose its arch or curvature, and joint stability, thus resulting in “flat footedness” in the mid-foot region.
Surgery is required for the majority of the tarsometarsal injuries. The treatment of tarsometatarsal injuries is usually done by reduction of the fraction or dislocation by means of screws that are inserted internally into the bones across the joints. These can be inserted through multiple punctures made on the skin without resorting to incisions on the foot. On the other hand, early treatment for Charcot foot includes the use of therapeutic footwear, immobilization of the foot and/or non-weight bearing treatment. Surgical treatments include orthopedic fixation devices that fixate the bones in order to fuse them into a stable mass. These orthopedic implant devices realign bone segments and hold them together in compression until healing occurs, resulting in a stable mass.
Various implants have been utilized for surgical treatment, including bone screws. While these devices allow fixation and promote fusion, they do not reinforce the joint nor do they restore the arch in a Charcot foot. Instead, the physician must estimate the arch and manually align the bones and deliver the screws to hold the bones in place, while reducing bone purchase. Intramedullary nails and/or a plate with a lag screw too have deficiencies. These intramedullary nails also do not reconstruct an arch that is lost due to Charcot foot disease nor do they reinforce the tarsometatarsal joint.
Moreover, infections and wound complications are a major concern in aforementioned procedures. Wound closure is technically demanding for the surgeon, and devices that add surface prominence, such as plates or exposed screws, add to the difficulty by requiring greater tissue tension during incision reapproximation. This increases the risk of postoperative wound infections and dehiscence that may ultimately result in limb amputation.
There is therefore a need for a hybrid intramedullary fixation assembly and method of use that overcomes some or all of the previously delineated drawbacks of prior fixation assemblies.
An object of the invention is to overcome the drawbacks of previous inventions.
Another object of the invention is to provide a novel and useful intramedullary fixation assembly that may be utilized to treat bones in a mid-foot region.
Another object of the invention is to provide joint reinforcement of the mid-foot region by utilizing a hybrid intramedullary screw and plate assembly.
Another object of the invention is to provide a system for treating deteriorating bones in a mid-foot region.
Another object of the invention is to provide a method for reinforcing the bones in the foot by delivering a plate and screw fixator that can be coupled to bones in a patient's foot.
In a first non-limiting aspect of the invention, an intramedullary fixation assembly for joint stabilization is provided and includes a plate member having a plurality of apertures, where the plate member comprises a first elongated portion and a second curved portion. The assembly further includes a plurality of metatarsal screws for coupling the plate member to the first elongated portion and to the metatarsal bone. An intramedullary screw member coupled to the first elongated portion applies compression to the tarsometarsal joint and a plurality of medial screws coupled to the second curved portion stabilizes the joint.
In a second non-limiting aspect of the invention, a method for reinforcing a tarsometarsal joint in a mid-foot region comprises six steps. Step one includes making a Medial Lis Franc incision in the mid-foot region of the human foot in order to gain access to the tarsometarsal joint. Step two includes Gunstocking the foot to expose the articular surface and removing the articulating cartilage. Step three includes inserting metatarsal screws into the tarsometatarsal plate member and into the metatarsal to anchor the metatarsal screws. Step four includes inserting the intramedullary screws into the tarsometarsal joint and applying compression. Step five includes inserting medial-lateral screws into the bones in the mid-foot region. The sixth step includes closing the incision, thereby reinforcing the tarsometarsal joint in the mid-foot region.
A further understanding of the invention can be obtained by reference to a preferred embodiment set forth in the illustrations of the accompanying drawings. Although the illustrated embodiment is merely exemplary of systems and methods for carrying out the invention, both the organization and method of operation of the invention, in general, together with further objectives and advantages thereof, may be more easily understood by reference to the drawings and the following description. The drawings are not intended to limit the scope of this invention, which is set forth with particularity in the claims as appended or as subsequently amended, but merely to clarify and exemplify the invention.
For a more complete understanding of the invention, reference is now made to the following drawings in which:
The invention may be understood more readily by reference to the following detailed description of preferred embodiment of the invention. However, techniques, systems, and operating structures in accordance with the invention may be embodied in a wide variety of forms and modes, some of which may be quite different from those in the disclosed embodiment. Consequently, the specific structural and functional details disclosed herein are merely representative, yet in that regard, they are deemed to afford the best embodiment for purposes of disclosure and to provide a basis for the claims herein, which define the scope of the invention. It must be noted that, as used in the specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly indicates otherwise.
Referring now to
As shown in
Further, proximal screw member 130 has a first smooth exterior portion 206 extending from end 212 of bulbous portion 202. Portion 206 comprises an internal aperture 214 that longitudinally traverses portion 206 in direction 201. Portion 206 terminates into a second generally tubular portion 216. Portion 216 may comprise internal circular aperture 220 that longitudinally traverses inside portion 216. Internal circular aperture 220 is aligned with apertures 214 and 208 along axis 203 to form a continuous opening (i.e., a cannula) from bulbous portion 202 to end 204. The continuous opening or cannula is provided to interact with a guide wire (not shown) by receiving the guide wire within the continuous opening thereby positioning and locating the proximal member 130. In other non-limiting embodiments, the proximal member 130 may be provided without apertures 220 and 214 (i.e., the proximal member is solid).
Furthermore, tubular portion 216 has a plurality of circular threads, such as threads 218, which are circumferentially disposed on the external surface of portion 216 and, with threads 218 having an external diameter 224. Portion 216 may also be provided with a self-tapping leading edge 222 to provide portion 216 with the ability to remove bone material during insertion of proximal screw member 130 into bone. It should be appreciated that the length of the proximal member 130 may be selected of varying lengths to allow a surgeon to fuse different joints in a foot (not shown).
As shown in
Distal member 140 further comprises a generally smooth portion 310 coupled to end 302. Portion 310 has a generally hexagonal shaped aperture 312, which opens into aperture 316 and which longitudinally traverses through portion 310 in direction 301. In other non-limiting embodiments, a star-shaped aperture, a square-shaped aperture, or any other shaped aperture may be utilized. Circular aperture 316 has a diameter 314 that is slightly larger than external diameter 224 of portion 216 and 206 of proximal screw member 130, with portions 216 and 206 being slidably received within aperture 316 of portion 310. Aperture 316 has a diameter that is smaller than diameter 226 of bulbous portion 202.
Portion 310 of distal member 140 terminates into a second generally cylindrical portion 318 which has a plurality of threads 324, which are circumferentially disposed on the external surface of portion 318. Portion 318 has an internal circular aperture 326 which is longitudinally coextensive with portion 318 in direction 301. Circular aperture 326 aligns with aperture 312 to form a continuous opening from end 302 to end 304.
As shown in
Planar portion 408 is coupled to planar portion 422, with portion 422 having a width slightly smaller than width of portion 408. Portion 422 terminates into a generally “U-shaped” portion 424 with portion 424 being orthogonal to portion 422. Further, portion 424 has a plurality of substantially similar sides 426 and 428 which are provided to be slidably coupled to grooves 326 and 328 of distal member 140.
In operation, sides 426 and 428 of instrument 120 are received in respective grooves 326 and 328 of distal member 140, of
In operation, and as best shown in
As shown in
Next, in step 708, the instrument 120 is coupled to the distal member 140 by coupling sides 426 and 428 of instrument 120 to respective grooves 326 and 328. In step 710, initial positioning of the proximal member 130 is assessed with the use of a guide wire through portion 412 (i.e., aiming device). Next, in step 712, a countersink drill is inserted through portion 412 and the proximal cortex is penetrated. In this step, a cannulated drill or guide wire is used to pre-drill the hole through the joints selected for fusion. In step 714, the proximal screw member 130 is inserted over the guide wire and into the distal member 140. Particularly, the proximal member 130 is inserted through tubular portion 412 (i.e., aiming device), causing proximal member 130 to travel through internal longitudinal aperture 420, into distal member 140 and further into bones 504, 506 and 508 until rigid connection with the tapered aperture 316 is made, thereby compressing the joint. In one non-limiting embodiment, a locking element (not shown) such as a plate or a washer is coupled to end 302 of the intramedullary fixation assembly 110 to further secure proximal threaded member 130 to distal member 140. Next, in step 716 the instrument 120 is removed and the dorsal Lis Franc (i.e., mid-foot) incision is closed. The method ends in step 718.
It should be appreciated that a plurality of intramedullary fixation assemblies, such as intramedullary fixation assembly 110, may be inserted into any of the bones of a foot 500 such as, but not limited to the metatarsal, cuneiform, calcaneus, cuboid, talus and navicular bones, in order to restore the natural anatomical shape of the arch of the foot 500. Thus, the fixation system 100, in one non-limiting embodiment, is utilized to couple the intramedullary fixation assembly 110 to the foot 500, which causes the metatarsal 504, medial cuneiform 504, navicular 506 and talus 508 bones to be aligned to the proper anatomical shape of an arch when assembled within foot 500. It should be appreciated that the intramedullary fixation assembly 110 is delivered through a dorsal midfoot incision, thereby reducing the disruption to the plantar tissues and/or the metatarsal heads while at the same time minimizing the tension on the skin. This allows for improved wound closure, reduced operating room time, reduction in the number of incisions required and reduction in the total length of incisions. It should also be appreciated that in other non-limiting embodiments, the intramedullary assembly 110 may be utilized with graft material (i.e., autograft, allograft or other biologic agent).
Referring now to
Further, and as shown in
As shown in
As shown in
Next, in step 1308, initial positioning of the intramedullary screw 835 is assessed the intramedullary screw 835 is inserted into the human foot 805 and compression is applied to lock the TMT plate member 810 to the metatarsal 815, the medial cuneiform 820, the navicular 865, and the talus 870 bones. In one non-limiting embodiment, the positioning of the intramedullary screw member 835 is assessed with the use of a guide wire and a countersink drill is inserted to pre-drill a hole in the metatarsal 815 and medial cuneiform 820. Next, in step 1310, medial-lateral screws, such as screws 840 and 845 are inserted to reinforce the tarsometatarsal joint by locking the TMT plate member 810 to the medial cuneiform 820, intermediate cuneiform 905, the lateral cuneiform 910, the cuboid 915, and the navicular 875 respectively. Next, in step 1312, medial Lis Franc (i.e., mid-foot) incision is closed. The method ends in step 1314.
It should be appreciated that a plurality of intramedullary fixation assemblies, such as intramedullary fixation assembly 800, may be inserted into any of the bones of a human foot 805 such as, but not limited to the metatarsal, cuneiform, calcaneus, cuboid, talus and navicular bones, in order to stabilize the joints in the foot 805. It should be appreciated that the intramedullary fixation assembly 800 is delivered through a medial midfoot incision, thereby reducing the disruption to the plantar tissues and/or the metatarsal heads while at the same time minimizing the tension on the skin. This allows for improved wound closure, reduced operating room time, reduction in the number of incisions required and reduction in the total length of incisions. It should also be appreciated that in other non-limiting embodiments, the intramedullary assembly 800 may be utilized with graft material (i.e., autograft, allograft or other biologic agent).
It should be understood that this invention is not limited to the disclosed features and other similar method and system may be utilized without departing from the spirit and the scope of the invention.
While the invention has been described with reference to the preferred embodiment and alternative embodiments, which embodiments have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, such embodiments are merely exemplary and are not intended to be limiting or represent an exhaustive enumeration of all aspects of the invention. The scope of the invention, therefore, shall defined solely by the following claims. Further, it will be apparent to those of skill in the art that numerous changes may be made in such details without departing from the spirit and the principles of the invention. It should be appreciated that the invention is capable of being embodied in other forms without departing from its essential characteristics.
This application is a continuation-in-part application of Non-Provisional application Ser. No. 12/456,808, filed Jun. 23, 2009, which claims the benefit of Provisional Application No. 61/132,932, filed Jun. 24, 2008, the entire contents of which are herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61132932 | Jun 2008 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12456808 | Jun 2009 | US |
| Child | 12587445 | US |
