Facet fusion implant

摘要

Facet fusion implants with various body geometries are provided. The bodies of the facet fusion implants can be configured to minimize migration of the implants when the implants are inserted into facet joints. Surgical methods and accompanying surgical instrumentation for inserting the facet fusion implants into facet joints are provided.

主权项

1. A facet fusion implant comprising:
an implant body elongate along a central axis, the implant body including a head portion disposed at a proximal end of the implant body, and a shaft portion that extends from the head portion toward a distal end of the implant body in a distal direction along the central axis, the head portion defining a head cross-sectional dimension that is perpendicular to the central axis, the shaft portion defining a plurality of thread peaks and valleys, and a minimum cross-sectional dimension that is aligned with the respective valley and is perpendicular to the central axis, wherein the head cross-sectional dimension does not exceed the minimum cross-sectional dimension, the shaft portion further defining a thread proximal face that extends from a respective peak to the respective valley at a location on the shaft portion that defines the minimum-cross-sectional dimension is aligned with respective valley, and a thread distal face that is opposite the thread proximal face along the central axis such that the thread proximal face faces the proximal end, wherein the thread proximal face defines a first radius of curvature, and the thread distal face defines a second radius of curvature that is greater than the first radius of curvature; and an engaging element carried by the head portion, the engaging element configured to engage with a complementary insertion instrument configured to insert the facet fusion implant into the facet joint between the first and second vertebral articulation surfaces.