Patent Application
20100137916
The present disclosure generally relates to orthopedic implants and systems for correction of spinal injuries and/or deformities, and more specifically, but not exclusively, concerns implants and systems for stabilizing a portion of the spine to allow correction and/or healing thereof. In some embodiments, the present disclosure is directed to improved apparatus, systems, and assemblies for stabilizing vertebrae.
Currently, in some instances the standard of care for treating spinal injuries and deformities, such as tumors, trauma, degenerative disc disease, etc., is a discectomy with interbody fusion. In some instances, supplemental fixation elements are also utilized to further stabilize the vertebrae to encourage fusion. For example, spinal plates may be securely attached to the vertebrae. In some instances, after fusion of a first spinal level, an adjacent spinal level may require treatment.
Accordingly, in some aspects, the present disclosure relates to spinal plates for use in stabilizing a spinal level adjacent to a previously treated spinal level. Alternatively, the spinal plates of the present disclosure are utilized to treat a spinal level such that a subsequent treatment of an adjacent spinal level is not inhibited. In some instances, the spinal plates of the present disclosure are sized and shaped for use in a level adjacent to a previously implanted stabilization device, such as an intervertebral disc and/or a spinal plate. In that regard, in some embodiments the spinal plates of the present disclosure are no or low profile plates. That is, the spinal plate is sized and shaped for positioning entirely within the disc space between adjacent vertebrae such that it does not extend beyond the outer boundaries of the vertebrae (no profile) or extends only slightly beyond the outer boundaries of the vertebrae (low profile). In some embodiments, the spinal plates of the present disclosure are configured to receive hyper-angulated screws. In some instances, the hyper-angulated screws facilitate optimal cortical bone purchase or penetration for fixedly securing the spinal plates to the vertebrae.
Therefore, there remains a need for improved apparatus, systems, and assemblies for stabilizing the spinal column.
In one embodiment, the present disclosure provides a spinal plate for use in stabilizing a spinal segment. In some instances the spinal plate includes openings extending therethrough to receive fixation members in a hyper-angulated orientation.
In another embodiment, the present disclosure provides a spinal plate for positioning between a first vertebra and a second vertebra. The spinal plate comprises a generally rectangular body portion. The body portion includes a first elongated engagement surface for fixedly engaging the first vertebra and a second elongated engagement surface opposite the first engagement surface for fixedly engaging the second vertebra. The second engagement surface extends substantially parallel to the first engagement surface. The first and second engagement surfaces are separated by a first height. A first axis extends substantially perpendicular to the first and second engagement surfaces. A first sidewall extends between and substantially perpendicular to the first and second engagement surfaces. A second sidewall extends between and substantially perpendicular to the first and second engagement surfaces opposite the first sidewall. The second sidewall extends substantially parallel to the first sidewall. The first and second sidewalls are separated by a first width. The first width is less than the first height. A first substantially cylindrical bore extends from the first sidewall to the second sidewall through the body portion at an oblique angle of at least 30 degrees with respect to the first axis. The first bore is sized to receive and mate with a bone fixation device for securing the body portion to the first vertebra.
In another embodiment, the present disclosure provides a spinal implant for stabilizing a pair of adjacent vertebrae without penetrating a sidewall of the vertebrae. The spinal implant comprises a central portion extending along a first plane, a first engagement portion extending from an upper part of the central portion, and a second engagement portion extending from a lower part of the central portion. The first engagement portion extends along a second plane that is at a first oblique angle with respect to the first plane. The second engagement portion extends along a third plane that is at a second oblique angle with respect to the first plane and substantially perpendicular to the second plane. A first opening extends through the first engagement portion substantially perpendicular to the second plane. The first opening is sized and shaped to receive and mate with a first bone fixation device for securing the first engagement portion to one of the adjacent vertebrae. A second opening extends through the second engagement portion substantially perpendicular to the third plane. The second opening is sized and shaped to receive and mate with a second bone fixation device for securing the second engagement portion to the other of the adjacent vertebrae.
In another embodiment, a method of stabilizing a first vertebra and a second vertebra adjacent to a previously stabilized spinal level that includes the first vertebra is disclosed. The method comprises providing a prosthetic device sized to fit substantially within a disc space between the first and second vertebra, gaining access to the disc space, and inserting the prosthetic device into the disc space in a low or no profile orientation with respect to the first and second vertebra. The prosthetic device extends within the disc space less than ⅓ of the length of the vertebral bodies of the first and second vertebra after insertion. A first bone anchor is extended through a first bore in the prosthetic device and engaged with an endplate of the first vertebra. The first bone anchor extends at an angle of approximately 45 degrees relative to a central axis of the prosthetic device. A second bone anchor is extended through a second bore in the prosthetic device and engaged with an endplate of the second vertebra. The second bone anchor also extends at an angle of approximately 45 degrees relative to the central axis the prosthetic device such that the first bone anchor and the second bone anchor extend substantially perpendicular to one another.
These and other aspects and advantages of the present disclosure will become apparent to those skilled in the art from the detailed description of the embodiments set forth below.
For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe these embodiments. It is nevertheless understood that no limitation of the scope of the disclosure is thereby intended. Modification of the disclosed embodiments and/or further application of the principles of the present disclosure are fully contemplated as would occur to one skilled in the art to which the present disclosure relates.
Referring now to
Referring now to
Referring more specifically to
The prosthetic device 30 also includes an anterior surface 40 and an opposing posterior surface 42. In the present embodiment, three openings 44, 46, and 48 extend through the prosthetic device 30 from the anterior surface 40 to the posterior surface 42. In that regard, each of the openings 44, 46, and 48 is a generally cylindrical bore sized to receive a bone fixation device for securing the prosthetic device 30 to the adjacent vertebra. In other embodiments, the openings 44, 46, and 48 have other geometrical profiles for receiving and/or mating with bone fixation members. In some embodiments, one or more of the openings 44, 46, and 48 has a different profile than one or more of the other openings 44, 46, and 48. In the present embodiment, the opening 48 is substantially centered about a midline or midpoint of the prosthetic device 30, while the openings 44 and 46 are positioned laterally on each side of the opening 48.
The cylindrical openings 44, 46, and 48 of the illustrated embodiment include a seat or collar 50, 52, and 54, respectively. Generally, each of the collars 50, 52, and 54 define a cylindrical bore having a reduced diameter relative to the majority of the corresponding opening 44, 46, and 48. For example, referring more specifically to
An axis 62 extends substantially perpendicular to the anterior and posterior surfaces 40, 42 of the device 30. The opening 46 extends along an axis 64 that is at an oblique angle 66 with respect to the axis 62. Accordingly, the opening 46 extends from an upper portion of the anterior surface 40 to a lower portion of the posterior surface 42 along the axis 64. In the present embodiment the axis 64 extends at an oblique angle 66 of approximately 45 degrees with respect to the axis 62. Generally, the oblique angle 66 is between about 20 degrees and about 70 degrees, and in some instances is between about 30 degrees and about 60 degrees. In some embodiments, the oblique angle 66 of the axis 64 relative to the axis 62 is selected to allow insertion of the bone fixation devices through the prosthetic device 30 to facilitate engagement of the bone fixation devices with cortical bone of an adjacent vertebra. In that regard, the prosthetic device 30 is considered suitable for use with hyper-angulated bone fixation devices, and in some embodiments hyper-angulated bone screws. Generally, in the context of the present disclosure hyper-angulated bone fixation devices, anchors, and/or screws are considered to be those that are configured to extend at an oblique angle greater than 25 degrees with respect to the axis 62 when received within the prosthetic device 30 and engaged with the adjacent bone structure.
Referring more specifically to
In the present embodiment, the opening 48 extends substantially perpendicular to the opening 46, as illustrated by
As described above, the opening 48 is substantially centered, while the openings 44 and 46 are positioned laterally on each side of the opening 48. In that regard, in some instances when the prosthetic device 30 is positioned within the spinal column the opening 48 is utilized to introduce a bone fixation device into the midline of a vertebra, while the openings 44 and 46 are utilized to introduce bone fixation devices in an offset configuration, spaced from the midline of the vertebra. Accordingly, in some instances the opening 48 is utilized to secure the prosthetic device 30 to a vertebra that has previously received bone anchors or screws in an offset configuration. Similarly, the openings 44 and 46 are utilized to secure the prosthetic device 30 to a vertebra that has previously received bone anchors or screws in a midline configuration. In that regard, while the opening 48 is illustrated as allowing the introduction of the midline bone fixation device into an upper vertebra adjacent the upper surface 32 and the openings 44 and 46 are illustrated as allowing the introduction of the offset bone fixation devices into a lower vertebra adjacent the lower surface 36, it fully contemplated that these orientations are reversed in other embodiments, such that the midline bone fixation device is introduced into the lower vertebra and the offset bone fixation devices are introduced into the upper vertebra.
Referring more specifically to
As shown in
The combination of the low or no profile orientation of the prosthetic device 30 along with the hyper-angulated openings 44, 46, and 48 facilitates a greater capture of cortical bone compared to traditional anterior plates that engage the cortical wall of the vertebrae, rather than the vertebral endplates. In that regard, the prosthetic devices of the present disclosure facilitate the use of longer bone screws that, in turn, create greater cortical bone engagement as they extend through the vertebral body via the hyper-angulated approach. Also, the combination of the low or no profile orientation of the prosthetic device 30 along with the hyper-angulated openings 44, 46, and 48 limits or eliminates impingement or coverage of the anterior longitudinal ligament, which results in less anatomic compromise and reduces the likelihood of an adjacent level being affected by calcification. In that regard, the prosthetic devices of the present disclosure are also utilized in some instances to decrease stress and/or forces across adjacent discs by providing a more localized and concentrated stiffness compared to typical anterior plates. Also, the prosthetic devices of the present disclosure are able to share loads and/or stresses imparted upon the vertebrae because the bone modulus of the vertebrae are not adversely affected, especially as compared to standard anterior plates and implantation methods. Further, the hyper-angulated approach allows the insertion of prosthetic devices at multiple levels with smaller incisions. Also, in some instances the bone screws and prosthetic devices are easier to access and remove during revision surgeries because of the hyper-angulated approach.
Referring now to
The prosthetic device 90 also includes an anterior surface 96 and an opposing posterior surface 98. In the present embodiment, the anterior surface 96 includes a recessed portion 100. The recessed portion 100 is positioned centrally between the upper and lower surfaces 92 and 94 and extends substantially along the entire length of the prosthetic device. The recessed portion 100 includes tapered surfaces 102 and 104 and planar surface 106. The planar surface 106 extends substantially parallel to the posterior surface 98. The tapered surface 102 extends from an upper portion of the anterior surface 96 and tapers at a constant rate to the planar surface 106. Similarly, the tapered surface 104 extends from a lower portion of the anterior surface 96 and tapers at a constant rate to the planar surface 106. In some instances, the recessed portion 100 allows for the nesting of the heads of the bone screws within the profile of the prosthetic device 90 as defined by the anterior surface 96. In that regard, the bone screw are engaged with the prosthetic device 90 such that the heads of the bone screws do not extend anteriorly beyond the anterior surface 96 and/or outside of the disc space into which the prosthetic device is implanted. Further, in some instances, the recessed portion 100 is utilized by an insertion tool to grasp the prosthetic device 90 during implantation. Further, the recessed portion 100 provides a viewing port in some instances. In that regard, a viewing port is utilized in some instances with longer prosthetic devices 90. Finally, the recessed portion 100 reduces the material density of the prosthetic device 90. Accordingly, in one particular embodiment the titanium density of the prosthetic device 90 is reduced by having the recessed portion 100.
The prosthetic device 90 also includes three openings 108, 110, and 112 extending through the prosthetic device 90 from the anterior surface 96 to the posterior surface 98. Each of the openings 108, 110, and 112 is a generally cylindrical bore sized to receive a bone fixation device for securing the prosthetic device 90 to the adjacent vertebra. In the present embodiment, the opening 112 is substantially centered about a midline or midpoint of the prosthetic device 90, while the openings 108 and 110 are positioned laterally on each side of the opening 112. As discussed above, this orientation of the openings allows the prosthetic device 90 to be utilized adjacent to a spinal level where an implant has been previously implanted, regardless of whether the previous implant is secured to the vertebra with a midline or offset orientation. More specifically, in some instances when the prosthetic device 90 is positioned within the spinal column the opening 112 is utilized to introduce a bone fixation device into the midline of a vertebra, while the openings 108 and 110 are utilized to introduce bone fixation devices in an offset configuration, spaced from the midline of the vertebra. Accordingly, the opening 112 is utilized to secure the prosthetic device 90 to a vertebra that has previously received bone anchors or screws in an offset configuration, while the openings 108 and 110 are utilized to secure the prosthetic device 90 to a vertebra that has previously received bone anchors or screws in a midline configuration.
Each of the openings 108, 110, and 112 of the illustrated embodiment include a seat 114, 116, and 118, respectively. Generally, each of the seats 114, 116, and 118 define a cylindrical bore having a reduced diameter relative to the majority of the corresponding opening 108, 110, and 112. In some instances the seats 114, 116, and 118 are sized and shaped to mate with a head portion of a multi-axial bone screw or other bone anchor. Similar to the openings 44, 46, and 48 of the prosthetic device 30, the openings 108, 110, and 112 extend at an oblique angle with respect to a central plane of the prosthetic device extending parallel to the upper and lower surfaces 92 and 94. Generally, the openings extend at an oblique angle between about 20 degrees and about 70 degrees, and in some instances between about 30 degrees and about 60 degrees relative to the central plane of the prosthetic device. In that regard, the oblique angles are selected to allow insertion of bone fixation devices through the prosthetic device 90 to facilitate engagement of the bone fixation devices with cortical bone of the adjacent vertebrae.
The prosthetic device 90 is suitable for use with hyper-angulated bone fixation devices, and in some embodiments hyper-angulated bone screws. In that regard, the prosthetic device 90 may be positioned entirely within the outer boundaries of the adjacent vertebrae in a no profile orientation when receiving the bone fixation devices. In some instances, at least a portion of the prosthetic device 90, such as a portion of anterior surface 96, extends beyond the anterior boundary of the vertebrae in at least one region when receiving the bone fixation devices. In such instances, the prosthetic device 90 is considered to be implanted in a low profile orientation.
Referring now to
Referring more specifically to
As shown, the central portion 126 includes an anterior surface 150 and a posterior surface 152. The anterior and posterior surfaces 150, 152 are substantially planar and extend substantially parallel to one another along axis 138. Accordingly, the central portion 126 has a substantially constant thickness 154 as measured between the surfaces 150 and 152. The upper portion 128 includes an anterior surface 156 and a posterior surface 158. The anterior and posterior surfaces 156, 158 are substantially planar and extend substantially parallel to one another along axis 142. Accordingly, the upper portion 128 has a substantially constant thickness 160 as measured between the surfaces 156 and 158. Finally, the lower portion 130 also includes an anterior surface 162 and a posterior surface 164. The anterior and posterior surfaces 162, 164 are substantially planar and extend substantially parallel to one another along axis 146. Accordingly, the lower portion 130 has a substantially constant thickness 166 as measured between the surfaces 162 and 164. In some instances, the thicknesses 154, 160, and 166 are substantially equal to one another such that the plate 122 has a substantially constant thickness. In other embodiments, the thicknesses 154, 160, and 166 of the central portion 126, upper portion 128, and lower portion 130, respectively, vary with respect to one another. In some embodiments, the thicknesses 154, 160, and 166 themselves vary within each of the central portion 126, upper portion 128, and lower portion 130, respectively. In some instances, the particular thicknesses 154, 160, and 166 are determined based on such factors as the material from which the plate is manufactured, the spinal level in which the plate is to be inserted, patient anatomy, and/or other factors.
Referring still to
As mentioned above, the openings 132, 134, and 136 extend through the plate 122 such that openings 132 and 134 extend through at least a part of the lower portion 130, while opening 136 extends through at least a part of the upper portion 128. In that regard the openings 132 and 134 extend substantially perpendicular to the anterior and posterior surfaces 162 and 164 of the lower portion 130. Similarly, the opening 136 extends substantially perpendicular to the anterior and posterior surfaces 156 and 158 of the upper portion 128. In the illustrated embodiment the upper and lower portions 128 and 130 extend at angles 144, 148 of approximately 45 degrees with respect to axis 140 such that the upper portion 128 extends substantially perpendicular to the lower portion 130. Accordingly, the opening 136 also extends substantially perpendicular to the openings 132, 134. More specifically, the opening 136 extends substantially perpendicular to axis 142, which in the present embodiment is substantially parallel to axis 146. Similarly, the openings 132, 134 extend substantially perpendicular to axis 146, which is substantially parallel to axis 142 in the present embodiment. In other embodiments, one or more of the openings 132, 134, and 136 extends at an oblique angle with respect to the corresponding upper or lower portion 128, 130 of the plate 122.
Generally, the angles 144, 148 of the upper and lower portions 128, 130 with respect to the axis 140 and/or the angle of the openings with respect to the upper and lower portions 128, 130 is selected to allow insertion of the fixation members 124 through the plate 122 to facilitate engagement of the fixation members with cortical bone of an adjacent vertebra. In that regard, the plate 122 is suitable for use with hyper-angulated bone fixation devices, and in some embodiments hyper-angulated bone screws. In some instances, the hyper-angulated screws facilitate optimal cortical bone purchase or penetration for fixedly securing the plate 122 to the adjacent vertebrae.
For example, referring to
Referring now to
Referring more specifically to
Referring more specifically to
Referring now to
In addition to the openings for receiving the bone anchors, the upper and lower sections 208, 210 include a recessed portion for receiving locking member 206 for securing the bone anchors 204 to the plate portion 202. Generally, any suitable locking member 206 is utilized to secure the bone anchors 204 in place. In some instances, the locking members 206 are similar to those described in U.S. Pat. No. 7,169,150 titled “NON-METALLIC ORTHOPEDIC PLATE”, which is hereby incorporated by reference in its entirety. In other instances, the locking members comprise a single Nitinol wire. Further, while not explicitly described with respect to some embodiments of the present disclosure it is understood that in some instances locking members are utilized with the other prosthetic devices of the present disclosure to secure the bone fixation members to the prosthetic devices.
Referring now to
Referring more specifically to
As illustrated, an axis 246 extends substantially perpendicular to an axis coincident with the radius of curvature 242 passing through the center point 244 and a midpoint of the plate 230. In that regard, the axis 246 is a tangent to the arc defined by the radius of curvature 242 at the midpoint of the plate 230. The bone screws 238 received by the middle region 232 extend substantially parallel to the axis coincident with the radius of curvature 242. Accordingly, the bone screws 238 received by the middle region 232 extend substantially perpendicular to the axis 246. Further, the bone screws 238 received by the upper region 234 extend along an axis 248, which is at an oblique angle 250 relative to the axis 246. Similarly, the bone screws 238 received by the lower region 236 extend along an axis 252, which is at an oblique angle 254 relative to the axis 246. Generally, the angles 250 and 254 are between about 20 degrees and about 70 degrees, and in some instances are between about 30 degrees and about 60 degrees. In the illustrated embodiment, each of the angles 250 and 254 is approximately 20 degrees. In this manner the plate 230 is shaped to receive the bone screws 238 through the upper and lower regions 234, 236 in a hyper-angulated orientation. In that regard, in some instances the bores or openings of the upper and lower regions 234, 236 that receive the bone screws 238 extend substantially parallel to the axes 248 and 250.
Referring more specifically to
Referring now to
Generally, the prosthetic devices, plates, and fixation members of the present disclosure are constructed of any suitable medical grade material. In that regard, desired features of the particular component, such as strength, flexibility, radiopaque/radiolucent, hardness, weight, wear resistance, and/or other characteristics, are considered in selecting the suitable material. Suitable biocompatible materials include metals, ceramics, polymers, and combinations thereof. For example, in some embodiments metals such as cobalt-chromium alloys, titanium alloys, nickel titanium alloys, and stainless steel alloys are suitable. In other embodiments, ceramic materials such as aluminum oxide or alumina, zirconium oxide or zirconia, compact of particulate diamond, or pyrolytic carbon are suitable. In yet other embodiments polymer materials are used, including members of the polyaryletherketone (PAEK) family such as polyetheretherketone (PEEK), carbon-reinforced PEEK, other modified PEEK materials, or polyetherketoneketone (PEKK); polysulfone; polyetherimide; polyimide; ultra-high molecular weight polyethylene (UHMWPE); cross-linked UHMWPE; silicon, polycarbonate urethanes, and nano-material treated polymers. In some instances, the materials are imbedded with one or more radiographic markers.
In some embodiments, the devices or individual components are constructed of bone or other tissue materials. Tissue materials include, but are not limited to, synthetic or natural autograft, allograft or xenograft, and may be resorbable or non-resorbable in nature. Examples of tissue materials include, but are not limited to, hard tissues, connective tissues, demineralized bone matrix and combinations thereof. Examples of resorbable materials that are used in some instances include, but are not limited to, polylactide, polyglycolide, tyrosine-derived polycarbonate, polyanhydride, polyorthoester, polyphosphazene, calcium phosphate, hydroxyapatite, bioactive glass, PLLA, PLDA, and combinations thereof. Further still, in some circumstances an interior portion or cavity of the prosthetic devices is packed with a suitable osteogenic material, bone morphogenetic proteins, or therapeutic composition to encourage bone growth. Osteogenic materials include, without limitation, autograft, allograft, xenograft, demineralized bone, synthetic and natural bone graft substitutes, such as bioceramics and polymers, and osteoinductive factors.
While specific embodiments have been illustrated and described in detail in the drawings and foregoing description, this is to be considered illustrative and not restrictive in character. It is understood that one of ordinary skill will be able to effect various alterations, substitutions of equivalents, and other modifications without departing from the concepts disclosed herein.
