DESCRIPTION
BONE SCREW SHIMMING AND BONE GRAFT CONTAINMENT SYSTEM AND METHOD
Technical Field
This invention generally relates to a device and a method which allows the accommodation of an orthopedic screw into a bone hole. More particularly, but not by way of limitation, the instant invention relates to a self adjusting system and method that includes a woven sleeve for shimming and salvaging holes for orthopedic fasteners, and for accepting and strengthening the grip of orthopedic fasteners. Additionally, the invention includes a system for delivering bone strengthening material, such as morselized bone graft material, to a location in a patient.
Background Art
The treatment of fractures frequently requires the attachment of a plate to the bone in order to ensure the correct positioning of the sections of bone that are to be fused together. To attach the plate to the bone one typically selects a plate which has pre-drilled screw hole locations. These pre-drilled screw holes are of a size that accepts a specific size of screw. Additionally, the plate also matches the size and type of bone being worked on. In order to produce the most secure attachment of the plate to the bone one should use screws which produce a close fit between the screw and the plate. The close fit between the screws and the plate results in a highly stable assembly. Unfortunately, however the close fit that provides a stable connection pre des little room for correction of
o pre-determined by the plate being used. Of course, one may change the plate to the larger plate, for example, but this option is usually not available due to the size and location of the bone being repaired. Moreover, a larger screw may cause even greater damage to the bone
5 being repaired. Finally, the anatomy of the location of being repaired may allow the use of a single diameter of screw. For example, the use of a large screw into the pedicle of a vertebra could break or split the pedicle. There are several known devices designed for w providing or enhancing the attachment orthopedic screws to bone. One example of these devices is shown in U.S. Patent No. 5,084,050 to Draenert, which teaches the use of an implant that includes a sheath that holds a material that swells out once inserted in into the bone is in order to provide a means for developing a firm support against the bone. This system is disadvantaged, however, due to the fact that it requires the drilling of a hole that is larger than the screw being used, and in that it does not provide an immediate secure hold against the
20 bone. Furthermore, the Draenert device is limited in its applicability in that is primarily useful in situations where a new portion of bone is to be grown in order to support the screw. Still further, the principle operation of the Draenert device, which provides for a dowel
25 shaped, hollow cylinder which expands to engage the surrounding bone, does not lend itself for a variety of situations, whether the situation requires the use of bone grafts or simply the accommodation of a screw where the screw hole is only slightly larger than the diameter
30 of the screw threads .
It will become apparent that the Draenert device is almost of no use as a repair or salvaging device for situations where the hole for the screw has become damaged due to brittleness or excessive torque imposed on
35 the screw. This is due to the fact that the damaged hole
will have been originally made to correspond to the holes in the plate being attached to the bone. In other words, the damaged hole in the bone is likely to be larger than the hole through the plate; meaning that an insert such as the Draenert device would not fit through the hole in the plate. Therefore, in order to salvage the hole using the Draenert device the surgeon would have to remove the plate, adapt the hole so that it can receive the Draenert device, and then re-fasten the plate over the screw holes . Another insert for use with bone screws in the repair of fractured bones is taught in U.S. patent No. 4,760,843 to Fischer et al . The Fischer patent teaches a connector with an aperture therethrough. The aperture is of a large diameter at one end and of a smaller diameter at the other end. This arrangement causes the end with the smaller diameter to expand once the bone screw is inserted into the device, gripping the inside of the hole in the bone. As can be understood from the above discussion, the use of an expanding device, such as the Fischer device, in situations where the patient's bone has already fragmented is likely to invoke even more than damage to the bone due to the fact that the hole is likely to be in brittle or soft bone. Thus, an attempt to repair a screw hole with the Fischer device is likely to result in even more damage to the hole. Still further, the Fischer device is nearly useless for the purpose of salvaging an existing hole during surgery. This is due to the fact that the stripped or damaged hole would be of a diameter that is approximately equal to the diameter of the hole thorough the plate; meaning that to salvage the hole, the surgeon would have to select the appropriate size Fischer connector and select a new screw that would cooperate with the Fischer connector. This is likely to produce a loose connection since the largest diameter of the plug sleeve portion of the device will necessarily be
approximately the same size as the hole in the plate, preventing proper gripping of the bone immediately below the plate. Finally, an expanding device may fracture or "blow out" bone in certain anatomical area, such as the tube-like confines of the vertebral pedicles, and may increase the risk of injury to surrounding anatomical structures .
The devices for use in osteosynthesis include U.S. Pat. No. 5,275,601 to Gogolewski et al . The Gogolewski patent teaches the use of a self locking resorbable screw which is made of the material with a modulus that is similar to the modulus of bone. The Gogolewski patent, however, does not teach suggest how to solve problems associated with salvaging a hole that has been damaged while attempting to fasten the screw within the hole.
Other approaches at ensuring that a bone screw is properly fastened or seated in the bone include the approach and taught in U.S. Pat. No. 5,607,304 to Bailey et al . where a threaded connector is used in combination with an implant to support a screw. Another example is found in U.S. Pat. No. 5,425,7762 to Cohen. The Cohen patent teaches the use of a pair of sections for surgical correction of damage to the bones of the digits of the foot. These patents, however, do not teach or suggest how to salvage a screw hole once it has become damaged due to a fracture of the sides of the hole.
Also of importance is the need for a device that can accommodate a wide variety of screws, and thus can be used with a variety of screws in a variety of applications. The ability of the device to accommodate a wide variety of screws allows the device to produce consistent, reliable results. Known devices, such as the Fischer device or the Draenert device, can complicate
procedures and introduce the possibility of error due to the fact that they must be matched to a particular diameter of screw. Therefore, is possible that the surgeon may find it necessary to remove one of the Fischer devices or the Draenert device after having inserted a device which is slightly smaller than the needed device .
Thus a review of known orthopedic devices reveals a need for a device and method for salvaging damaged holes that have been drilled into patients bone in order to attach a screw to the bone.
Still further, a review of known devices reveals a needed for a method and a system that allows the surgeon to salvage or correct a hole that has become enlarged by erosion of the sides of the hole.
Still further, there remains a need for a system for salvaging a hole by providing self adjusting shims that accommodate to the hole in a radial manner in order to prevent bunching or folding and accumulation of the shimming material .
There remains a need for a system and method for salvaging a damaged hole for an orthopedic fastener, the system and method allowing modification of the thickness and materials used in salvaging the hole.
There remains a need for a system and method for salvaging a damaged hole for an orthopedic fastener, without having to remove plates or other devices that have been successfully attached in order to access the damaged hole.
There remains a need for a system and method that cooperates with a screw being driven into a bone and allows a surgeon to tailor the amount and kind of agents used in attachment of the screw, and thus allowing the surgeon to create an asymmetrical insert, if necessary, to accommodate the needs of the patient.
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The need to use the instant invention arising from damage to the hole caused by over tightening of a screw being driven into the hole, or due to fraying of the hole due to osteoporosis of the bone material. Moreover, the instant invention will allow the user to adapt an existing hole so that the hole can accept a fastener which would otherwise be too small for adequately gripping the sides of the hole.
It will be appreciated that an important aspect of the invention includes the use of woven fibers which can move relative to one another in order to adjust the diameter or size of the sleeve to accommodate for differences in the size of hole and fastener being used.
It is also important to note that the fact that a series of the sleeves or "screw socks" of the instant invention may be stacked within one another allows the surgeon to adjust the thickness and buildup of material to enhance the purchase of the screw. This stackability allows the achievement of important new and useful results in that a surgeon may place a collapsed sleeve within another sleeve, an external sleeve, and between the screw and the external sleeve in an asymmetrical fashion. This arrangement would allow the surgeon to repair an off centered or out of round screw hole. Clearly, the same principle could be used to place bone graft material, or other desired material, symmetrically or asymmetrically between the screw and the external sleeve.
Also of importance is that the instant invention satisfies the need for a system that includes a single sleeve made in accordance with the principles taught herein can accommodate a wide variety of screws, and thus can be used with a variety of screws in a variety of
applications. Thus, the instant invention exhibits the ability to accommodate a wide variety of screws allows the device to produce consistent, reliable results.
Thus, the disclosed invention includes a device and method for salvaging damaged holes that have been drilled into a patient's bone in order to attach a plate to the bone. Particularly, the instant invention allows a surgeon to salvage or correct a hole that has become enlarged by erosion of the sides of the hole.
Still further, the instant invention satisfies the need for a system for salvaging a hole by providing system including self adjusting shims that accommodate to the hole in a radial manner in order to prevent bunching, or folded and uneven accumulation of the shimming material .
Furthermore, it will be appreciated that the disclosed system and method for salvaging a damaged hole for an orthopedic fastener allows stacking of the sleeves, which in turn allows modification of the thickness and materials used in salvaging the hole.
In light of the above and accompanying description, it will be appreciated that the disclosed invention may be used in tendon or ligament reattachment procedures . These procedures typically involve the forming of a bore or tunnel that accepts means for anchoring and reattaching the ligaments to the bone. The anchoring means used in these ligament reattachment procedures may also work come loose due to over-tightening of threaded anchors, for example. Thus it can be appreciated that the instant invention can be used to salvage or bolster the attachment of these means used to anchor or reattach the ligaments to the bone. It is contemplated that the
o reattachment or enhancement of the grip of the anchor used in the ligament reattachment procedure would be carried out in a manner similar to the manner in which screw holes are salvaged as taught herein.
It should also be understood that while the above 5 and other advantages and results of the present invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings, showing the contemplated novel construction, combinations and elements as herein described, and more particularly w defined by the appended claims, it is understood that changes in the precise embodiments of the herein disclosed invention are meant to be included within the scope of the claims, except insofar as they may be precluded by the prior art.
Brief Description of Drawings
The accompanying drawings illustrate preferred embodiments of the present invention according to the best mode presently devised for making and using the instant invention, and in which:
FIG. 1 is a perspective view showing the arrangement and use of the instant invention together with a plate.
FIG. 2 is a perspective view of a preferred embodiment of a sleeve made in accordance with the principles disclosed herein.
FIG. 3 illustrates the adjustment or expandability of the sleeve in an axial direction.
FIG. 3A illustrates the adjustment or expandability of the sleeve in a radial direction.
FIG. 3B illustrates the attachment of the fibers to achieve a body which tends to remain closed.
FIG. 3C illustrates the use of the rod to insert a sleeve through a plate and into a hole in the bone.
FIG. 4 is a side view of a pair of sleeves being stacked, one inside the other.
FIG. 5 is a side view of another embodiment of the instant invention, the embodiment including a sleeve with a generally conical shape and two open ends.
FIG. 6 is a side sectional view with a portion of the sleeve broken away to illustrate the fact that the hole in the bone is larger than the hole in the plate,
o and the cooperation of the sleeve and that threads of the fastener in taking up the space between the threads of the fastener and the bone.
FIG. 7 is a perspective view of a variation of an embodiment of the instant invention, the embodiment shown 5 mounted over a fastener before insertion into the bone.
FIG. 8 illustrates the use of several sleeves and other materials to fill a severely damaged hole.
Best Mode for Carrying Out the Invention
While the invention will be described and disclosed here w in connection with certain preferred embodiments, the description is not intended to limit the invention to the specific embodiments shown and described here, but rather the invention is intended to cover all alternative embodiments and modifications that fall within the spirit is and scope of the invention as defined by the claims included herein as well as any equivalents of the disclosed and claimed invention.
Turning now to Fig. 1 where a preferred embodiment of the sleeve 10 of the instant invention has been shown
20 in relation to a plate 12 which is to be mounted on to a bone 14 by means of fasteners 16. As can be observed from figure 1, the plate 12 includes a curvature that has been adapted for the bone to which is to be mounted. Is to be understood that the use of plates, such as the
25 plate 12 shown on Fig. 1, is common practice in situations where a severe fracture is to be stabilized by the plate, or situations where several sections of bone or several different bones are to be stabilized in order to allow the healing between the sections of bone. Thus
30 it will be appreciated that for a particular bone there is likely to be a single plate that will fit properly
over the bone, and a specific plate may only have faster holes at locations which may not necessarily avoid the fractured or injured areas of the bone.
To fasten the plate to the bone, the surgeon must drill holes, such as hole 48 into the bone 14 to at locations that match the hole locations on the plate.
The plate is then placed over the desired area and fastened in place with orthopedic or bone screws . As discussed earlier, the situation arises where while driving the screws 16 into the bone the hole 48 becomes stripped or enlarged. In the following discussion a damaged hole, or any hole which may benefit from the use of the instant invention, such as the hole used for anchoring a ligament or tendon, will be referred to as a damaged hole 48A. It is important to emphasize that it is contemplated that the instant invention may be used in any situation where it is desired to enhance the grip of the fastening means, and that it has been discovered that the instant invention is particularly useful in situations where the hole has been damaged, but it is contemplated that the instant invention may also be used with unstripped or undamaged holes. Accordingly, to salvage the damaged hole 48A, the sleeve 10 is driven into the hole 48A by means of a rod 20. The rod 20 will preferably include a first end 22 and a second end 24. The first end 22 will preferably include a smooth, rounded surface. The second end 24 may include the handle or other means for gripping the rod 20.
Turning now to Fig. 2 it will be understood that the sleeve 10 includes a sleeve shaped body 26. The sleeve shaped body 26 includes an external surface 28, as well as an internal surface 30, a first end 32, a mid portion 34, and a second end 36. The second end 36 will preferably include means for engaging the first end 22 of
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Turning now to Fig. 4 and Fig. 5, it will be appreciated that the closing action of the instant invention allows the stacking of several sleeves 10 to provide a thicker stack up for situations where larger amounts of space needs to be taken up. Also shown on Fig. 5 is a sleeve 10A with a generally conical shape, shown together with a layer of a material, referred to herein has an agent material 44, the may be placed between two sleeves 10 that are stacked within one another. This allows the physician to place a layer of an agent material which exhibits bone growth enhancing properties or other biological properties, and thereby providing a customized treatment to the area where the stack of sleeves 10 have been applied.
It is important to note that the resiliency of the fibers 38, and the ability of the woven fibers 38 move relative to one another, produces important new and useful results that could not be achieved with known devices. For example, the resiliency of the fibers 38 can aid in holding and centering the sleeve 10 within the hole in the bone 14. Additionally, the ability of fibers 38 move or slide past one another allows radial of adjustment of the size of the sleeve 10. The radial adjustment of the size sleeve 10 allows uniform build-up of the sleeve material about the fastener 16. Moreover, as discussed above, the resiliency of the fibers 38 will allow the sleeve 10 to open up once inserted in the hole 48, and grip or bias the sleeve 10 against the hole 48, allowing the removal of the rod 20 while leaving the sleeve 10 within the hole 48. Of course, has shown on
Fig. 3B it is contemplated that the bias of the fibers 38 may be arranged so that the bias tends to close the sleeve 10, as compared to biasing the fibers 38 to
o maintain a generally opened sleeve arrangement . In a preferred embodiment of the invention the fibers 38 are made from a suture type material, or of a suture type material that has been impregnated with bone growth stimulating agent, such as a bone morphogenic protein
5 (BMP, or an antibiotic agent to provide protection against infection. The bone morphogenic protein would promote bone growth around the fastener 16. Additionally, it is contemplated that the suture material may be of a bioabsorbable or non-bioabsorbable material or a o combination of both.
It will be understood that the instant invention also includes a method for a salvaging a damaged hole. The method includes the steps of providing a woven sleeve 10. The sleeve having an elongated, sleeve shaped body s 26. The sleeve shaped body 26 having an interior portion, or surface 30. Then providing an elongated rod 20, and then using the elongated rod 20 for inserting at least one woven sleeve 10 into the into the hole, so that the sleeve remains in the hole. Then, with insertion of
20 the fastener into the sleeve the difference in the size of the damaged hole 48A and the fastener is taken up by the sleeve, as seen in FIG. 6.
It is contemplated that the woven sock, or sleeve 10, can also be used as a container for delivering
25 morselized bone graft material to a desired location.
Thus, it will be appreciated that the instant invention presents an important advancement in the art in that traditionally the application of morselized bone graft material is accomplished by placing the graft against the
30 bone with no means for preventing migration or dislodgement of the graft. The previously described woven sleeve 10, or "screw sock," whether manufactured with bone growth enhancing material provides an ideal
"bag" or container which can retain the bone graft material at a desired position. Additionally, it is important to note that the surgeon may tailor a mixture of the bone graft material to suit the needs of the patient. Thus, for example, the surgeon may combine bone graft material with bone growth enhancing material within a single sleeve 10, and then suture the sleeve closed to allow placement of the mixture within the sleeve 10 a desired location. Clearly is contemplated that this location may be within yet another sleeve 10, and against a screw, to allow filling of an oblong or irregularly shaped hole.
A sack made from a sleeve 10, as described above, and filled with morselized bone graft material, such as the material known under the trademarks Allograft or the material known under the trademark Autograft, together with BMP (for example) could be introduced through trocars to allow for percutaneous placement of the material at a desired location in the patient's body. Incidentally, the sleeve 10 could also be used prophylactically to provide enhanced purchase for the bone screw when the underlying bone is known to be osteoporotic and brittle. Thus, it will be appreciated that the versatility of the woven sleeve 10 of the instant invention allows the surgeon to carry out many of the tasks that required distinctly different devices, such as the known devices described above. The ability to carry out these functions with a single device made in accordance with the principles taught herein reduces the need to carry a large inventory of these other known devices in the operating room. The elimination of this large variety of devices not only reduces the cost to the hospital, but also reduces the risk of selecting the wrong device where several devices of similar appearance are available.
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