Bone hemi-lumbar interbody spinal implant having an asymmetrical leading end and method of installation thereof
OwnerGary K. Michelsoninventor
Life of this patent
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Abstract
An interbody spinal implant is formed of cortical bone adapted for placement across an intervertebral space formed across the height of a disc space between two adjacent vertebral bodies. An asymmetrical leading end on the implant is adapted to sit upon the peripheral areas, such as the apophyseal rim and the apophyseal rim area, of the vertebral end plate region of the vertebral bodies without protruding therefrom. The asymmetrical leading end allows for the safe use of an implant of maximum length for the implantation space into which it is installed. The implant can also include an asymmetric trailing end adapted to sit upon the more peripheral areas of the vertebral end plate region of the vertebral bodies.
Claims89
An interbody spinal implant for insertion at least in part across a disc space between adjacent vertebral bodies of a human spine, the vertebral bodies having an anterior aspect and a posterior aspect, said implant comprising:
- a leading end for insertion first into the disc space, a trailing end opposite said leading end, and therebetween a length along a mid-longitudinal axis of said implant, said leading end being asymmetrical;
- opposed portions between said leading and trailing ends adapted to be placed within the disc space to contact and support the adjacent vertebral bodies, said opposed portions being non-arcuate along at least a portion of the length of said implant, said implant being formed of bone;
- an interior facing side wall, an exterior facing side wall opposite said interior side wall, and a width therebetween, said width of said implant being less than approximately one-half of the maximum width of the adjacent vertebral bodies into which said implant is adapted to be inserted, said interior and exterior side walls connecting said opposed portions and said leading and trailing ends, said interior side wall adapted to be oriented toward another implant when inserted within the disc space;
- at least one through-hole having a maximum cross-sectional dimension greater than 0.5 mm between said interior facing and said exterior facing side walls passing completely through said implant from opposed portion to opposed portion and adapted to hold bone growth promoting material for permitting for the growth of bone from vertebral body to vertebral body through said implant;
- a first distance as measured from said leading end to a plane perpendicular to and bisecting the length along the mid-longitudinal axis of said implant that is greater than a second distance as measured from said perpendicular plane to the junction of said leading end and said exterior side wall;
- and
- a third distance as measured from the junction of said leading end and said interior side wall to a plane perpendicular to and bisecting the length along the mid-longitudinal axis of said implant that is greater than said second distance.
An interbody spinal implant for linear insertion at least in part across a disc space between adjacent vertebral bodies of a human spine, the vertebral bodies having an anterior aspect and a posterior aspect, said implant comprising:
- a leading end for insertion first into the disc space, a trailing end opposite said leading end, and therebetween a length along a mid-longitudinal axis of said implant, said implant being non-threaded and adapted for linear insertion in a direction along the mid-longitudinal axis of said implant, said leading end being asymmetrical, less than half of said asymmetric leading end being along a line perpendicular to the mid-longitudinal axis of said implant in a plane dividing said implant into an upper half and a lower half;
- opposed portions between said leading and trailing ends adapted to be placed within the disc space to contact and support the adjacent vertebral bodies, said opposed portions being arcuate along at least a portion of the length of said implant, said implant being formed of bone;
- an interior facing side wall, an exterior facing side wall opposite said interior side wall, and a width therebetween, said width of said implant being less than approximately one-half of the maximum width of the adjacent vertebral bodies into which said implant is adapted to be inserted, said interior and exterior side walls connecting said opposed portions and said leading and trailing ends, said interior side wall adapted to be oriented toward another implant when inserted within the disc space;
- a first distance as measured from said leading end to a plane perpendicular to and bisecting the length along the mid-longitudinal axis of said implant that is greater than a second distance as measured from said perpendicular plane to the junction of said leading end and said exterior side wall;
- and
- a third distance as measured from the junction of said leading end and said interior side wall to a plane perpendicular to and bisecting the length along the midlongitudinal axis of said implant that is greater than said second distance.
A method for installing an interbody spinal implant into a disc space formed across a spinal disc and into vertebral bodies adjacent the spinal disc and installing an implant therein, said method comprising the steps of:
- providing an implant having a leading end for insertion first into the disc space, the leading end being adapted to allow for the seating of the implant on at least one of the anterior and posterior portions of the apophyseal rim bone area without at least a portion of the implant proximate the leading end substantially extending beyond the outer dimensions of the vertebral bodies, a trailing end opposite the leading end, and therebetween a length along a mid-longitudinal axis of the implant, opposed portions between the leading and trailing ends adapted to be placed within the disc space to contact and support the adjacent vertebral bodies, the implant being formed of bone, and having at least one through-hole having a maximum cross-sectional dimension greater than 0.5 mm between said interior facing and said exterior facing side walls passing completely through said implant from opposed portion to opposed portion and adapted to hold bone growth promoting material for permitting for the growth of bone from vertebral body to vertebral body through said implant;
- and
- installing the implant with at least the leading end of the implant positioned in contact with the bone proximate and including at least one of the anterior and posterior portions of the apophyseal rim area of the vertebral bodies.
Dependencies are inferred from the claim text.