Interbody spacer

Abstract

An interbody spacer includes concave lateral surfaces extending at an angle with respect to the longitudinal axis. In one aspect, the interbody spacer includes upper and lower convex surfaces defined by an arc extending from a center point offset from the spacer midpoint. In another aspect, lateral edges of the upper and lower surfaces are also defined by convex arcs extending from a center point offset from the spacer midpoint.

1 - 36 . (canceled) 
     
     
         37 . An interbody spacer, comprising:
 a body extending along a longitudinal axis between a first end and a second end, the body comprising a top surface and an opposing bottom surface each extending between the first and second ends, the body comprising a first lateral surface and an opposite second lateral surface each extending between the top and bottom surfaces and between the first and second ends,   wherein the top and bottom surfaces each include a series of spaced apart projections extending transverse to the longitudinal axis, the projections each extending between and connecting the first and second lateral surfaces, and   wherein opposite ends of each projection are tapered from an adjacent one of the first and second lateral surfaces to a crest of the projection to facilitate rotation of the body about the longitudinal axis.   
     
     
         38 . An interbody spacer as recited in  claim 37 , wherein the body is rounded between the top surface and the first and second lateral surfaces and between the bottom surface and the first and second lateral surfaces 
     
     
         39 . An interbody spacer as recited in  claim 37 , wherein at least a portion of each of the first and second lateral surfaces is concavely curved between the top and bottom surfaces. 
     
     
         40 . An interbody spacer as recited in  claim 37 , wherein the top and bottom surfaces are each continuously convexly curved between the first and second ends. 
     
     
         41 . An interbody spacer as recited in  claim 37 , wherein:
 the first end defines a nose that is convexly curved between the top and bottom surfaces and between the first and second lateral surfaces; and   the second end defines a planar end surface extending perpendicular to the longitudinal axis.   
     
     
         42 . An interbody spacer as recited in  claim 37 , wherein the body is free of any openings extending into the top and bottom surfaces and the first and second lateral surfaces. 
     
     
         43 . An interbody spacer, comprising:
 a body extending along a longitudinal axis between a first end and a second end, the body comprising a top surface and an opposing bottom surface each extending between the first and second ends, the top and bottom surfaces being continuously curved between the first and second ends, the body comprising a first lateral surface and an opposite second lateral surface each extending between the top and bottom surfaces and between the first and second ends,   wherein the body is rounded between the top surface and the first and second lateral surfaces and between the bottom surface and the first and second lateral surfaces,   wherein at least a portion of each of the first and second lateral surfaces is concavely curved between the top and bottom surfaces.   
     
     
         44 . An interbody spacer as recited in  claim 43 , wherein the top and bottom surfaces each comprise a series of spaced apart projections, each of the projections extending perpendicular to the longitudinal axis. 
     
     
         45 . An interbody spacer as recited in  claim 44 , wherein the projections each include a crest that is rounded. 
     
     
         46 . An interbody spacer as recited in  claim 43 , wherein:
 the body has a length defined by a distance between the first and second ends;   the body defines a midlength plane extending perpendicular to the longitudinal axis that is equidistant from each of the first and second ends; and   the top and bottom surfaces are each convexly curved between the first and second ends such that the body has a maximum height defined by a distance between the top and bottom surfaces at a location that is offset from the midlength plane.   
     
     
         47 . An interbody spacer as recited in  claim 46 , wherein:
 the first end defines a leading end and the second end defines a trailing end, the leading end having a maximum width defined by a distance between the first and second lateral surfaces that is greater than that of the trailing portion; and   the location is positioned closer to the leading end than the trailing end.   
     
     
         48 . An interbody spacer as recited in  claim 43 , wherein the first and second lateral surfaces are each continuously convexly curved between first and second ends. 
     
     
         49 . An interbody spacer as recited in  claim 43 , wherein:
 the body has a length defined by a distance between the first and second ends;   the body defines a midlength plane extending perpendicular to the longitudinal axis that is equidistant from each of the first and second ends; and   the first and second lateral surfaces are each convexly curved between first and second ends such that the body has a maximum width defined by a distance between the first and second lateral surfaces at a location that is offset from the midlength plane.   
     
     
         50 . An interbody spacer as recited in  claim 49 , wherein:
 the first end defines a leading end and the second end defines a trailing end, the leading end having a maximum width defined by a distance between the first and second lateral surfaces that is greater than that of the trailing portion; and   the location is positioned closer to the leading end than the trailing end.   
     
     
         51 . method for positioning an interbody spacer between vertebrae, comprising:
 providing an interbody spacer comprising a body extending along a longitudinal axis between a first end and a second end, the body comprising a top surface and an opposing bottom surface each extending between the first end and the second end, the top and bottom surfaces each comprising a series of spaced apart projections, the body comprising a first lateral surface and an opposite second lateral surface each positioned between the top surface and the bottom surface;   positioning the interbody spacer between the vertebrae such that one of the first and second lateral surfaces faces a superior vertebra and the other of the first and second lateral surfaces faces an adjacent inferior vertebra; and   rotating the interbody spacer between the vertebrae such that the projections of one of the top and bottom surfaces engage the superior vertebra and the projections on the other of the top and bottom surfaces engages the inferior vertebra.   
     
     
         52 . A method as recited in  claim 51 , wherein:
 the body is rounded between the top surface and the first and second lateral surfaces and between the bottom surface and the first and second lateral surfaces; and   each of the first and second lateral surfaces is concavely curved between the top and bottom surfaces.   
     
     
         53 . A method as recited in  claim 51 , wherein:
 the body has a length defined by a distance between the first and second ends;   the body defines a midlength plane extending perpendicular to the longitudinal axis that is equidistant from the first and second ends; and   the top and bottom surfaces are each convexly curved between the first and second ends such that the body has a maximum height at a location that is offset from the midlength plane.   
     
     
         54 . A method as recited in  claim 53 , wherein opposite ends of each projection are tapered from an adjacent one of the first and second lateral surfaces to a crest of the projection to facilitate rotation of the body about the longitudinal axis. 
     
     
         55 . A method as recited in  claim 51 , wherein the first and second lateral surfaces are each smooth and free of any projections. 
     
     
         56 . A method as recited in  claim 51 , wherein the body comprises PEEK.