Devices and methods for treatment of facet and other joints
View Patent ↗Embodiments of the present invention describe methods, devices and instruments for resurfacing or replacing facet joints, uncovertebral joints and costovertebral joints. The joints can be prepared by smoothing the articular surface on one side, by distracting the joint and by implant insertion. Implants can be stabilized against a first articular surface by creating a high level of conformance with said first articular surface, while smoothing the second articular surface with a surgical instrument with a smooth mating implant surface.
1. An implant for use in a vertebral facet joint of a patient, said implant consisting of: a body at least partially configured to be inserted between first and second opposing articular joint surfaces of the vertebral facet joint, the body of the implant including an interpositional body portion extending along a first longitudinal axis between a first end and a second opposing end of the body of the implant, said implant interpositional body portion including a first articular surface and a second opposing articular surface extending between the first and second ends of the body of the implant and spaced from one another by a thickness of the interpositional body portion of the implant, the first articular surface of the body of the implant configured to engage the first articular joint surface of the vertebral facet joint, and the second articular surface of the body of the implant configured to engage the second opposing articular joint surface of the vertebral facet joint when the interpositional body portion of the implant is inserted between the first and second articular joint surfaces of the vertebral facet joint, at least a portion of the first articular surface of the interpositional body portion of the implant having a concave shape, and at least a portion of the first articular surface of the interpositional body portion of the implant is formed of a non-pliable material and having a three dimensional shape that conforms with a three dimensional shape of the first articular joint surface of the vertebral facet joint of the patient, wherein information used for forming the three dimensional shape of the first articular surface of the body of the implant is derived from electronic image data of the vertebral facet joint of the patient, wherein at least one of the first and second ends of the body of the implant is enlarged relative to the interpositional body portion of the implant, that includes the first and the second articular surfaces of the body of the implant, and defining an implant extrapositional body portion extending along a second longitudinal axis traversing the first longitudinal axis, such that the body of the implant forms a T-shape anchor for further engaging an outer surface of the vertebral facet joint with bone facing surfaces of the implant extrapositional body portion to prevent the body of the implant from sliding or dislodging through the facet joint, such that the implant extrapositional body portion is configured to be located in an extra-articular position when the implant interpositional body portion is implanted in the vertebral facet joint, and wherein the body of the implant, including the interpositional and the extrapositional body portions of the implant, is free of through holes for receiving an attachment mechanism.
2. The implant of claim 1 , wherein contours of at least a portion of the second articular surface of the body of the implant substantially conform to corresponding contours of the second articular joint surface of the vertebral facet joint.
3. The implant of claim 1 , wherein at least a portion of the second articular surface of the body of the implant substantially forms a negative of a corresponding portion of the second articular joint surface of the vertebral facet joint.
4. The implant of claim 1 , wherein the first articular surface of the body of the implant is configured to secure the body of the implant relative to the first articular joint surface when the implant interpositional body portion is implanted in the vertebral facet joint.
5. The implant of claim 1 , wherein at least a portion of the first articular surface of the body of the implant is configured to interdigitate with a corresponding portion of the first articular joint surface of the vertebral facet joint when the implant interpositional body portion is implanted in the vertebral facet joint.
6. The implant of claim 1 , wherein the second articular surface of the body of the implant is substantially smooth.
7. The implant of claim 1 , wherein the other one of the first and second ends of the body of the implant is enlarged relative to a middle portion of the interpositional body portion of the implant and is configured to enlarge a space between the first and second articular joint surfaces of the vertebral facet joint.
8. The implant of claim 1 , the body of the implant includes an attachment mechanism configured to secure the body of the implant in the vertebral facet joint.
9. The implant of claim 8 , wherein the attachment mechanism is a protrusion selected from the group consisting of a pin and a fin projecting from the second articular surface of the body of the implant.