The present application is directed to an implant, and more particularly, to an implant with a non-rotating base and a rotating member that is movable between first and second rotational positions.
Various medical procedures use an implant that is positioned within the patient between supporting skeletal structures. One example is an implant positioned between vertebral members of the spine. The spine is divided into four regions comprising the cervical, thoracic, lumbar, and sacrococcygeal regions. The cervical region includes the top seven vertebral members identified as C1-C7. The thoracic region includes the next twelve vertebral members identified as T1-T12. The lumbar region includes five vertebral members L1-L5. The sacrococcygeal region includes nine fused vertebral members that form the sacrum and the coccyx. The vertebral members of the spine are aligned in a curved configuration that includes a cervical curve, thoracic curve, and lumbosacral curve. Intervertebral discs are positioned between the vertebral members and permit flexion, extension, lateral bending, and rotation.
Various conditions may lead to damage of the intervertebral discs and/or the vertebral members. The damage may result from a variety of causes including but not limited to a specific event such as trauma, a degenerative condition, a tumor, or infection. Damage to the intervertebral discs and vertebral members can lead to pain, neurological deficit, and/or loss of motion.
Various procedures include replacing the entirety or a section of a vertebral member, the entirety or a section of an intervertebral disc, or both. One or more replacement implants may be inserted to replace the damaged vertebral members and/or discs. The implants are configured to be inserted into the intervertebral space and contact against the remaining adjacent vertebral members.
The present application is directed to an implant that fits within a space between skeletal structures and for contacting and spacing apart the skeletal structures. The implant may include a base with first and second sides configured to fit within the space and contact against the skeletal structures. The base may have a height measured between the sides. The implant may include a member having a first height measured between a first pair of opposing sides and a second height measured between a second pair of opposing sides. The first height may be less than or equal to the height of the base and the second height may be greater than the height of the base. The implant may include a connector to connect the member to the base such that the member is able to rotate relative to the base between first and second rotational positions. The member may be rotatable relative to the base between the first rotational position with the first and second sides of the base and the first pair of opposing sides of the member facing in a common direction and one of the second pair of opposing sides facing towards the base, and a second rotational position with the sides of the base and the second pair of opposing sides of the member facing in the common direction and one of the first pair of opposing sides facing towards the base.
The implant may also include a base with a height measured between opposing sides and being sized to fit within the space and contact against the skeletal structures. The implant may include a base a member rotatably connected to the base. The member may also include first and second opposing sides and third and fourth opposing sides. The member may have a first height measured between the first and second sides and a second height measured between the third and fourth sides. The first height may be less than or equal to the height of the base and the second height may be greater than the height of the base. The member may be rotatable relative to the base between a first rotational position with the third side facing towards the intermediate section of the base and a second rotational position with the first side facing towards the intermediate section of the base and the member extending outward beyond the base.
The application also includes a method of spacing apart skeletal structures. The method may include positioning an implant within a space between skeletal structures with the implant including a base and a member rotatably connected to the base. The method may include contacting sides of the base of the implant against the skeletal structures with the member in a first rotational position with at least one of opposing non-contact sides facing towards the skeletal structures and contact sides of the member facing away from the skeletal structures with one of the contact sides facing towards the base. The method may further include that while the sides of the base are contacting the skeletal structures, rotating the member about 90° to a second rotational position and moving the non-contact sides away from the skeletal structures and moving the contact sides of the member into contact with the skeletal structures such that the base and the member simultaneously contact the skeletal structures.
The various aspects of the various embodiments may be used alone or in any combination, as is desired.
The present application is directed to an implant for spacing apart skeletal structures, such as vertebral members. An implant 10 is illustrated in
Returning to
The base 20 also includes opposing first and second sides 21, 22 on the central section 24 and arms 25. One or both sides 21, 22 may include contact features such as teeth or surface texturing to facilitate contact with the skeletal members 200 and prevent or reduce movement of the implant 10 after insertion into the space 201. The base 20 includes a height H measured between the sides 21, 22. The height H may be the same along the length of the base 20, or may vary with one or more regions being greater than other regions.
The base 20 may also include one or more openings 23 to receive the one or more connectors 40. The openings 23 may extend completely through the base 20 as illustrated in
Additional openings 26 may also extend through the central section 24 for accessing the member 30. In one embodiment, the openings 26 extend through the central section for placing bone growth material between the base 20 and the member 30. Openings 26 may also extend through the height of the base 20 (i.e., through the base 20 from the opposing sides 21, 22). Openings in this orientation may be configured to receive bone growth material.
The base 20 may include a single, unitary construction as illustrated in
The member 30 includes a body with a variety of different sides.
Member 30 also includes a second pair of opposing sides 32a, 32b that are spaced apart a greater distance and have a larger height h2. At least one of these sides 32a, 32b faces towards the base 20 when the member 30 is in the first rotational position.
Various openings 34 may extend through the member 30. The openings 34 may extend from side 31a to side 31b, and from sides 32a to side 32b.
The connector 40 pivotally connects the member 30 to the base 20. The connector 40 includes one or more extensions 41 that fit into the corresponding openings 23 in the base 20. The extensions 41 may extend outward from the member 30. The extensions 41 may be part of the member 30 (i.e., an integral, one-piece construction that includes the extensions 41 and the member 30), or the extensions 41 be separate elements that are attached to the member 30.
The extension 41 may include a substantially circular cross-sectional shape with one or more flat sides 44. The one or more flat sides 44 may facilitate engagement with the extension 41. The one or more flat sides 44 may also be a gauge to determine the amount of rotation of the member 30.
One embodiment illustrated in
In a similar construction, the elements of the base 20 and member 30 are reversed. The base 20 includes the connector 40 that includes one or more extensions 41 that extend outward and fit into corresponding openings in the member 30. These extensions may be integrally constructed to the base 20, or may be separate elements that are attached to the base 20.
The member 30 may be connected to the base 20 at two or more locations.
The member 30 may also be connected to the base 20 with a single elongated fastener that extends through the member 30 and into openings 23 in the base 20.
The member 30 rotates about 90° relative to the base 20 between the first and second rotational positions. The connector 40 may be configured to limit an amount of movement between the base 20 and member 30 to within the 90° range. Alternatively, the connector 40 may allow the member 30 to rotate within a greater range (i.e., more than 90°) relative to the body 20.
The member 30 is attached to the base 20 with a fastener (not illustrated) that extends through and aligns the openings 23, 76. As the member 30 is rotated from the first rotational position to the second rotational position, the tabs 77 on the member 30 slide along the respective ramps 70, 71 from the starting points 74 towards the ending points 75. The member 30 is rotated and the tabs 77 slide beyond the end points 75 and into the slots 73. The tabs 77 are captured in the slots 73 thus securing the member 30 in the second rotational position.
The implant 10 may include a single engagement structure 79 and corresponding slots 73, or may include multiple structures 79.
The relative sizes between the body 20 and the member 30 may vary.
The member 30 may be connected to the base 20 at opposing ends as illustrated in
Two or more members 30 may be included in an implant 10.
In embodiments with multiple members 30, the members 30 may be independently rotatable, or may rotate together. In one embodiment, the multiple members 30 are connected together. A rotational force applied to one of the members 30 results in each of the members 30 being rotated between first and second rotational positions. In other embodiments, the members 30 remain independent and each must be individually rotated between the first and second rotational positions. In embodiments with three or more members 30, subsets of the members 30 may be connected to rotate together (e.g., two members are connected with a third being independent).
The shape of the members 30 may vary.
The members 30 may have various heights across the contact sides 32a, 32b.
The member 30 may extend outward from the base 20 in different manners when the member 30 is in the second rotational position.
The implant 10 may also include one or more wings 50, 51 operatively connected to the member 30 as illustrated in
Each of the wings 50, 51 may be connected to one of the extensions 41 that extend outward from the base 20. Alternatively, one or more fasteners may extend outward from the member 30 and connect to the wings 50, 51.
The implant 10 may be inserted into the space 201 with an insertion tool 300 as illustrated in
The elongated section 302 includes a housing 313 that extends around all or a portion of a shaft 306 and a driver 308. The housing 313 is hollow to extend around the shaft 306 and the driver 308. As illustrated in
The shaft 306 is rotatable within the housing 313 and includes a proximal end 304 and an opposing distal end 305. The proximal end 304 is positioned outward beyond a proximal end of the housing 313 and is configured to connect to the connector 303. The distal end 305 of the shaft 306 may include a receptacle 307 sized to engage with the extension 41 on the implant 10. The receptacle 307 may include one or more flat sides that align with and engage the flat sides 44 of the extension 41. Rotation of the handle 301 causes the shaft 302 to rotate thus moving the member 30 from the first rotational position to the second rotational position. The shaft 306 may be constructed from a single continuous piece, or may include two or more separate pieces that are connected together.
The driver 308 extends through the housing 313 and is configured to also engage with the implant 10. The driver 308 includes a proximal end with a knob 309 that is positioned on the exterior of the housing 313, and a distal end that forms an extension 310 that extends outward from the distal end of the housing 313. The extension 310 may be threaded to engage within a threaded opening 26 in the implant 10. The driver 308 is also rotatable relative to the housing 313 such that rotation of the knob 309 rotates the driver 308 causing extension 310 to thread into the opening 26. The driver 308 may be flexible as it meanders through the interior of the housing 313.
In use, the implant 10 is initially connected to the insertion tool 300. This includes placing the implant 10 at the distal end 305 of the elongated section 302. The extension 311 on the housing 313 is positioned in the slot 83 in the implant 10. Further, the extension 310 on the driver 308 is inserted into the opening 26 in the implant 10. This may include surgical personnel rotating the knob 309 on the proximal end of the driver 308 and threading the extension 310 into the threaded opening 26 in the implant 10. Further, the receptacle 307 at the distal end of the shaft 306 is placed over and engages the extension 41 on the implant 10.
The implant 10 is positioned in the first rotational position. This provides a reduced overall height and facilitates insertion into the patient and into the space 201 between the skeletal members 200. The surgical personnel manipulate the insertion tool 300 and the implant 10 is placed in the space 201 with the side 21 of the base 20 contacting against the first skeletal member 200 and side 22 contacting against the second skeletal member 200. With the member 30 in the first rotational position, the sides 31a, 31b are facing in the same direction as sides 21, 22 and towards the skeletal members 200. One, both, or neither of the sides 31a, 31b may be in contact with the skeletal members 200.
Bone growth material may be placed into the implant 10 prior to or after the implant 10 is positioned in the space 201. After the implant 10 is properly positioned in the space 201, the member 30 is rotated to the second rotational position. This includes rotating the handle 301 on the insertion tool 300 thereby rotating the shaft 306 and hence the member 30.
In some embodiments, the extent of rotation of the member 30 is performed visually by the surgical personnel. They may observe the flat side 44 of the extension and determine when the member 30 has been rotated the correct amount. The surgical personnel may also use tactile feedback to determine rotation. Other embodiments may include limiters to control the extent of rotation. This may include engagement structures 79 as illustrated in
Rotation of the member 30 to the second rotational position causes the sides 32a, 32b to move into contact with the skeletal members 200. The height h2 of the member 30 is configured to support the skeletal members 200 at the proper spacing.
The member 30 may be secured after rotation to the second rotational position. A fastener 67 (see
After the implant 10 is properly positioned in the space 201 while in the second rotational position, the insertion tool 300 may be removed from the implant 10. This may include rotating the knob 309 and removing the extension 310 from the implant 10. Further, the insertion tool 300 is moved outward away from the implant 10 to disengage from the implant 10.
The implant 10 may also be manually inserted into the space 201 and rotated to the second rotational position.
The base 20 may be constructed to have an articulating configuration. Base 20 includes multiple sections that are connected together and provide for pivoting motion between the sections.
During rotation of the member 30, the extension 41 rotates and translates in the opening 23.
In some embodiments, the rotational axis A is centered in the member 30. Other embodiments may include the rotational axis A is offset in the member 30. This may include offset between sides 32a and 32b, and/or between sides 31a, 31b.
A rotatable implant is also disclosed in U.S. patent application Ser. No. 12/845,809 filed Jul. 30, 2010 which is herein incorporated by reference in its entirety.
In one embodiment, the implant 10 includes a base 20 with a height of 10 mm for insertion when the member 30 is in the first rotational position, and includes the member 30 with a height of 14 mm for supporting the skeletal members 200 when the member 30 is in the second rotational position.
The height h1 of the member 30 in the first rotational position may be smaller than the height H of the base 20. The height h1 may also be equal to the height H.
The implant 10 is sized to space apart skeletal members 200. One application includes the implant 10 positioned within the intervertebral space between the bodies of vertebral members. The implant 10 may also be used to treat long bones (e.g., femur, tibia, fibula, humerus).
The various elements of the implant 10 may be constructed of biocompatible materials of various types. Examples of implant materials include, but are not limited to, non-reinforced polymers, reinforced polymer composites, PEEK and PEEK composites, shape-memory alloys, titanium, titanium alloys, cobalt chrome alloys, stainless steel, ceramics and combinations thereof. Reinforcing materials may include carbon, fiberglass, metal pieces, or any other effective reinforcing material. The implant 10 may include radiographic markers to provide the ability to monitor and determine radiographically or fluoroscopically the location of the implant 10 within the patient. In some embodiments, the implant elements may be constructed of solid sections of bone or other tissues. In other embodiments, the implant elements are constructed of planks of bone that are assembled into a final configuration. The implant may be constructed of planks of bone that are assembled along horizontal or vertical planes through one or more longitudinal axes of the implant. 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 other tissue materials include, but are not limited to, hard tissues, connective tissues, demineralized bone matrix and combinations thereof. Examples of resorbable materials that may be used include, but are not limited to, polylactide, polyglycolide, tyrosine-derived polycarbonate, polyanhydride, polyorthoester, polyphosphazene, calcium phosphate, hydroxyapatite, bioactive glass, and combinations thereof.
The implant 10 may be used during surgical procedures on living patients. The implant 10 may also be used in a non-living situation, such as within a cadaver, model, and the like. The non-living situation may be for one or more of testing, training, and demonstration purposes.
Spatially relative terms such as “under”, “below”, “lower”, “over”, “upper”, and the like, are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first”, “second”, and the like, are also used to describe various elements, regions, sections, etc and are also not intended to be limiting Like terms refer to like elements throughout the description.
As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise.
The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.