Artificial disc
First Claim
1. An intervertebral disc protheses for replacement of a disc between an upper vertebrae and a lower vertebrae comprising,a lower member having a lower mounting surface for attachment against an upper surface of said lower vertebrae, said lower member having an upper surface,an upper member having an upper mounting surface for attachment against a lower surface of said upper vertebrae, said upper member having a lower surface,a pivot ball extending from a post from one of said upper member and said lower member,the other of said upper member and said lower member having an elongate cavity therein,means on said other of said upper member and said lower member for retaining said pivot ball in said cavity,an elastomeric shock absorbing member between said upper member and said lower member, said elastomeric shock absorbing member compressible between a relief condition wherein said upper surface of said lower member has a first spacing from said lower surface of said upper member, and a compressed condition wherein said upper surface of said lower member has a second spacing from said lower surface of said upper member, said second spacing being less than said first spacing, andsaid pivot ball is vertically movable within said elongate cavity to permit compression of said shock absorbing member from said relief condition to said compressed condition.
0 Assignments
0 Petitions
Accused Products
Abstract
A disc prosthesis for insertion between vertebrae of the spin has upper and lower members and a pivot ball retained in a socket to prevent the ball from becoming removed from the socket. Also, a shock absorbing member is fitted between the upper and lower member of the prosthesis. The upper and lower members are also vertically movable to compress the shock absorbing member and absorb shock in the spine.
-
Citations
6 Claims
-
1. An intervertebral disc protheses for replacement of a disc between an upper vertebrae and a lower vertebrae comprising,
a lower member having a lower mounting surface for attachment against an upper surface of said lower vertebrae, said lower member having an upper surface, an upper member having an upper mounting surface for attachment against a lower surface of said upper vertebrae, said upper member having a lower surface, a pivot ball extending from a post from one of said upper member and said lower member, the other of said upper member and said lower member having an elongate cavity therein, means on said other of said upper member and said lower member for retaining said pivot ball in said cavity, an elastomeric shock absorbing member between said upper member and said lower member, said elastomeric shock absorbing member compressible between a relief condition wherein said upper surface of said lower member has a first spacing from said lower surface of said upper member, and a compressed condition wherein said upper surface of said lower member has a second spacing from said lower surface of said upper member, said second spacing being less than said first spacing, and said pivot ball is vertically movable within said elongate cavity to permit compression of said shock absorbing member from said relief condition to said compressed condition.
-
4. An intervertebral disc prostheses for replacement of a disc between an upper vertebrae and a lower vertebrae comprising,
a lower member having a lower mounting surface for attachment against an upper surface of said lower vertebrae, an upper member having an upper mounting surface for attachment against a lower surface of said upper vertebrae, one of said upper member and said lower member have a base portion with a tubular central portion having an inner diameter, an annular collar around said tubular central portion, said annular collar having a central opening, a pivot ball extending from a post from the other of said upper member and said lower member, said pivot ball having a diameter less than said inner diameter, said central opening of said collar having a diameter which is less than said diameter of said pivot ball whereby said collar retains said pivot ball in said tubular central portion, an elastomeric shock absorbing member between said upper member and said lower member, said elastomeric shock absorbing member movable between a relief condition wherein said upper member has a first spacing from said lower member and a compressed condition wherein said upper member has a second spacing from said lower member, and said pivot ball vertically movable within said tubular central portion of said one of said upper member and said lower member to permit compression of said shock absorbing member from said relief condition to said compressed condition.
Specification