Transverse rod connectors with osteoconductive material

The present application is directed to transverse connectors that connect first and second vertebral rods that extend along the spine. In one embodiment, the transverse connector includes an elongated base with a first receiver at a first section of the base to receive the first vertebral rod, and a second receiver at a second section of the base to receive the second vertebral rod. Osteoconductive material is positioned on at least the first receiver.

BACKGROUND

The present application is directed to transverse rod connectors and, more particularly, to rod connectors that include osteoconductive material.

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.

Vertebral rods may be implanted to support and position vertebral members in one or more of these regions. The rods extend along a section of the spine and are connected to the vertebral members with one or more fasteners. The rods may have a curved configuration to conform to the curvature of the spine. Often times two or more rods are connected together and work in combination to support and position the vertebral members. The rods may have the same or different shapes and sizes depending upon their position along the spine. The vertebral rods may be used during fusion of two or more vertebral members.

One or more transverse connectors may attach the rods together for further stabilization and positioning. The connectors have a first connection to the first rod, and a second connection to the second rod.

One drawback is that transverse connectors can sometimes increase the possibility of a failed fusion between two or more of the vertebral members. It is commonly believed that the transverse connectors disrupt the bony fusion mass that forms during fusion and therefore creates a weak point in the fusion.

SUMMARY

The present application is directed to transverse connectors that connect first and second vertebral rods that extend along the spine. In one embodiment, the transverse connector includes an elongated base with a first receiver at a first section of the base to receive the first vertebral rod, and a second receiver at a second section of the base to receive the second vertebral rod. Osteoconductive material is positioned on at least the first receiver.

The various aspects of the various embodiments may be used alone or in any combination, as is desired.

DETAILED DESCRIPTION

The present application is directed to transverse connectors with osteoconductive material to facilitate fusion between vertebral members.FIG. 1illustrates a schematic view of a transverse connector10that includes a base20and receivers30. The base20is sized to extend across a section of the spine. In the embodiment ofFIG. 1, the base20includes a length to span across a spinous process201of the vertebral member200. Receivers30are positioned on each end of the base20. Receivers30are adapted to engage with one of the vertebral rods100. One or both of the base20and receivers30include osteoconductive material50to facilitate bone growth along the spine in the area of the transverse connector10.

FIG. 2illustrates an embodiment with a pair of vertebral rods100extending along a length of the spine. The transverse connector10extends between and attaches to each of the rods100. In this embodiment, the rods100extend along the spine on opposite sides of the midline M that extends through the spinous processes201of the vertebral members100. The transverse connector10may also be used in contexts with more than two vertebral rods100, and to connect rods100positioned on one side of the midline M.

The base20may include a variety of shapes and sizes. Base20may be curved or may be substantially straight. In one embodiment as illustrated inFIGS. 1 and 2, base20is a single, unitary member.FIG. 3illustrates another embodiment with the base20formed from separate members including a first member21and a second member22. The members21,22are connected together by a fastener23. Fastener23also provides for positioning the members21,22at various angles to accommodate the vertebral rods100.FIG. 4illustrates another embodiment with the base20formed by first and second members21,22that are positioned in an overlapping arrangement with the first member21positioned above the second member22(i.e., the first member21is posterior to the second member22when the connector10is positioned within the patient). Each member21,22includes scallops26that align together to form the receivers30that receive the vertebral rods100.

The receivers30are adapted to engage with the vertebral rods100. The receivers30may include arms31as illustrated inFIGS. 1 and 3. Each of the arms31is shaped to extend around at least a portion of the vertebral rod100. The arms31may be attached to the base20by fasteners32. Receivers30may also be formed by the base20.FIG. 4illustrates one embodiment with the receivers30formed between members21,22of the base20.FIG. 5illustrates another embodiment with the ends of the base20being shaped to form receivers30. In these various embodiments, each of the receivers30positioned along the base20may be the same or different.

The receivers30may be located relative to the vertebral members200and the vertebral rods100in different manners.FIGS. 1 and 4include embodiments with the receivers30shaped to fit between the vertebral rods100and the vertebral members200.FIG. 5includes an embodiment with the receivers30positioned away from the vertebral member200.

Examples of connectors10are disclosed in U.S. Patent Application Publications 2007/0270818 and 2007/0173829, each incorporated herein by reference.

The osteoconductive material50is positioned to facilitate bone growth that results in a stronger fusion mass. The osteoconductive material50provides a substrate for attachment of bone and is positioned in areas that will cause a stronger fusion mass. In one embodiment, the osteoconductive material50is coated across the entire connector10that includes the base20and receivers30. In other embodiments, the osteoconductive material50is on just isolated elements or sections of the elements.

FIG. 1includes an embodiment with the under sides of the receivers31and sections of the base20are coated with osteoconductive material50. The coating may be applied in a similar manner to each lateral side of the connector10, or may be applied in different manners. By way of example, the osteoconductive material50is continuously coated across the left receiver arm31ofFIG. 1, and discretely coated onto sections of the right receiver arm31ofFIG. 1. The osteoconductive material50is also coated across the entire under side of the base20.FIG. 4includes the osteoconductive material50applied across the entire under side of member22that contacts against the vertebral member200.FIG. 5includes the osteoconductive material50applied to the under side of the base20.

In the various embodiments, the connector10may include a single type of osteoconductive material50, or may include two or more different types of osteoconductive material50.

In one embodiment as illustrated inFIG. 6, the base20and the receivers30are constructed from an osteoconductive material50. In one embodiment, the entire base20and receivers30are constructed from the same osteoconductive material50. In another embodiment, sections of the base20and/or receivers30are constructed from the osteoconductive material50. In another embodiment, the base20and/or receivers30are constructed from two or more different osteoconductive materials50.

In some embodiments, particular sections of the connector10do not include osteoconductive material50because they may interfere with the structural workings. In the embodiment ofFIG. 1, the threaded sections of the base20that receive the fasteners32are not coated because it may interfere with the threads. In the embodiment ofFIG. 3, member22may not be coated to allow for the member22to be movable for adjusting a distance between the receivers30.

A variety of osteoconductive materials50may be applied to the connector10. One type of material is a fill material that may be used to attach the connector10to the vertebral rods100. Examples of fill materials include demineralized bone matrix (DBM), bi-calcium phosphate matrix, platelet gel, calcium phosphate-based materials, methomathactuloid, cranial plast, ceramics, polymers, calcium-sulfate, hydroxyapatite, tricalcium phosphate, or one or more of the previous in combination.

Another type of material is osteoinductive and/or osteogenic material that forms bone and may improves the connection with the cortical bone tissue at the outer shell of the vertebral members100. Examples of osteogenic materials40include hydroxyapatite, bone morphogenetic protein (BMP), LIM mineralized proteins (LMP), DBM, platelet gel, osteoinductive peptides, growth factors, pharmaceutical agents such as antibiotics, pain medication, anti-inflammatory drugs, steroids, or one or more of the previous in combination. The osteoconductive material50may also include a combination of the fill and osteogenic materials.

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. In one embodiment, the osteoconductive material50is positioned away from the fastener32to faciliate subsequent removal of the fastener32. 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.