Patent Application
20120283836
The present invention relates to an implant for orthopedic surgery.
To repair the damaged vertebrae, artificial vertebral body is come out in the medical community aboard, such as titanium cage (TMC). The titanium cage is a hollow skeleton made of titanium alloy formed by titanium alloy plate of several meshes and set in a circle, the inner of the titanium cage is disposed with ring-shaped support. When insert the TMC, the corpectomy or the total removal of the vertebral body needs to be done, and then pack the bone graft in it. The raised spots on the both ends of the titanium cage withstand the cephalad and the caudad endplates separately. With bone growth between vertebral body and bone graft inside the TMC, the fusion of the index level and adjacent vertebral body will be achieved. The minute vessels will grow with the bone graft through the meshes of the titanium cage, achieving the treatment of interbody fusion.
But the titanium cage has these disadvantages below:
1). To implant the bulky size of cylindrical titanium cage, corpectomy or the total removal of the damaged vertebral body needs to be done, the patient will blood much and it will damage the blood supply to the vertebrae.
2). The titanium cage is fixed to the vertebrae by the raised spots on the both ends of the titanium cage withstanding the cephalad and the caudad endplates separately, which will be easily caved in.
3). Bone grafting could not be took in the surrounding of the titanium cage, and the titanium cage does not have the effect of damper to keep out the vertebrae canal, so that the bone graft could enter in and compress the nerve structure.
4). The titanium cage would encase the implant bone, keep off the X-ray and prevent from observing the growth of the bone.
The object of the present invention is to provide interbody fusion device, which could prevent the disadvantages of the titanium cage.
The present invention provides interbody fusion device, which is a hollow skeleton made of titanium alloy for holding bone graft, wherein the skeleton is a U-shaped plate, the front wall is equipped with several holes while the back wall has not; the upper end and the lower end of the bottom of the U-shaped plate are configured separately with inclined hole of ladder shaped, the bigger end of the inclined hole is placed on the bottom surface of the bottom of the U-shaped plate, and the smaller end of the inclined hole is placed on the corresponding surface of the bottom of the U-shaped plate; the inclined hole of the U-shaped plate is disposed with screw inside.
The outward of the cap of the two screws are circle-arc surface, the boundary between the bigger end and the smaller end of the inclined holes is circle arc section, which is coupled to the circle-arc surface.
The outer surface of the back wall of the U-shaped plate is configured with slope along the free end; the outer surface of the front wall is configured with slope along the free end. The slope provides an insert guide head for the U-shaped plate in the surgery.
The upper ends and lower ends of the back wall, front wall and the bottom of the U-shaped plate are configured with flanges. The flanges produce friction between the U-shaped plate and the caudad endplate of the upper vertebral body and the cephalad endplate of the lower one, which improves the stability of the U-shaped plate.
The upper and the lower ends of the U-shaped plate is configured parallel to each other or not. The upper and the lower ends of the U-shaped plate parallel to each other makes it more fit to the thoracic vertebrae end-plate; the upper and the lower ends of the U-shaped plate unparallel to each other makes it more fit to the lumbar vertebrae end-plate; they could prevent collapse or fracture of the upper and the lower lumbar vertebrae due to the partial pressure.
The present invention of interbody fusion device (it could be also called U-shaped artificial vertebrae) comprises a titanium alloy U-shaped plate of 0.6 cm and two screws locking the U-shaped plate between the caudad endplate of the upper vertebral body and the cephalad endplate of the lower one. The inner and the front of the U-shaped plate could be implanted with large amount of bone graft, making it easily to form biological connection. Corpectomy or the total removal of the damaged vertebral body is not needed and only one-third of posterior part of vertebral body is removed because of the small volume of the U-shaped plate. It keeps the anterior column and part of middle column of the damaged vertebral body. It retains most of the vertebrae bone, which reduces blooding and supports the vertebrae blood supply, beneficial to the interbody fusion of the anterior-middle column of the damaged vertebrae. The back wall of the U-shaped plate serving as a gate is disposed without holes, which prevent the entry of the bone graft to the vertebrae canal and the compression to the nerve structures. The front wall of the U-shaped plate is disposed with holes, making it easier for the biological connecting. The minute vessel grows accompanying with the bone by the holes. The inclined holes at the upper and the lower end of the bottom of the U-shaped plate are disposed with screws inside, the screws lock to the caudad endplate of the upper vertebral body and the cephalad endplate of the lower one, preventing the collapse of the implant. The interbody fusion situation could be direct evaluated by the observing the healing of the front two-third vertebrae when taking imaging examination.
The object of the present invention is to provide a preferred embodiment of fusion device for vertebral body. The
The U-shaped plate 1 is hollow skeleton made of titanium alloys with thickness of 0.6 cm.
The outer surface of the back wall 11 of the U-shaped plate 1 is configured with slope 111 along the free end. The middle section of the back wall 11 near the bottom 14 is configured with a back groove 112 extending to the edge.
Refer to the
The slope 111 on the back wall 11 and the slope 121 on the front wall 12 of the U-shaped plate 1 provide a leading section for the placement of the U-shaped plate in the surgery. The back groove 112 on the back wall 11 and the front groove 122 on the front wall 12 of the U-shaped plate provide a gripper for holding the U-shaped plate in the surgery.
Refer to the
The screw 2 is made of titanium alloy.
Refer to the
The back wall 11 of the U-shaped plate 1 goes towards the vertebrae canal, preventing the entry of the bone graft to the vertebrae canal. If the bone graft gets into the vertebrae canal, nerve compression would occur. The flanges 13 and flanges 15 on the both ends of the u-shaped plate 1 withstand the caudad endplate of the upper vertebral body 4 and the cephalad endplate of the lower vertebral body 5 separately. Two screws 2 pass though the corresponding inclined holes 141 on the both end of the bottom of the U-shaped plate 1, and the two screws 2 reach out of the both ends of the bottom. The cone thread sections 22 of the two screws 2 lock the bottom of the cephalad lumbar vertebrae 4 and the top of the caudad lumbar vertebrae 5, and the circle arc surface 232 on the cap 23 of the screw 2 contact with the circle- arc section 1411 of the inclined hole 141. The U-shaped plate 1 is fixed between the cephalad lumbar vertebrae 4 and the caudad lumbar vertebrae 5 by the two screws 2.
The present invention provides with the second embodiment of the interbody fusion device for the thoracic vertebral body.
The U-shaped plate 6 is hollow skeleton made of titanium alloys with thickness of 0.6 cm.
The outer surface of the back wall 61 of the U-shaped plate 6 is configured with slope 611 along the free end. The middle section of the back wall 61 near the bottom 64 is configured with a back groove 612 extending to the edge.
The outer surface of the front wall 62 of the U-shaped plate 6 is configured with slope 621 along the free end. The middle section of the front wall 62 near the bottom 64 is configured with a front groove 622 extending to the edge. Four holes 623 are disposed on the front wall 62 evenly disposed.
The slope 611 on the back wall 61 and the slope 621 on the front wall 62 of the U-shaped plate 6 provide a leading section for the placement of the U-shaped plate in the surgery. The back groove 612 on the back wall 11 and the front groove 622 on the front wall 62 of the U-shaped plate provide a gripper for holding the U-shaped plate in the surgery.
Refer to the
Refer to the
The back wall 61 of the U-shaped plate 6 goes towards the vertebrae canal, and the back wall 61 can prevent the entry of the bone graft to the vertebrae canal. If the bone graft gets into the vertebrae canal, nerve compression would occur. The flanges 63 on the both ends of the u-shaped plate 6 withstand the caudad endplate of the upper vertebral body 8 and the cephalad endplate of the lower vertebral body 9 separately. Two screws 2 pass though the corresponding inclined holes 641 on the both end of the bottom of the U-shaped plate 6, and the two screws 2 reach out of the both ends of the bottom. The cone thread sections 22 of the two screws 2 lock the bottom of the cephalad thoracic vertebrae 8 and the top of the caudad thoracic vertebrae 9, and the circle arc surface 232 on the cap 23 of the screw 2 contact with the circle-arc section 6411 of the inclined hole 641. The U-shaped plate 6 is fixed between the cephalad thoracic vertebrae 8 and the caudad thoracic vertebrae 3 by the two screws 2.
Although the present invention has been fully described by ways of preferred embodiments with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scopes of the present invention, they should be construed as being included therein.
