Lordotic spinal implant
AssigneeSulzer Spine-Tech Inc.
InventorsDouglas W. Kohrs, Paul M. Sand
Life of this patent
Estimating the term…
Abstract
A lordotic implant has a frusto-conical shape with external threads. Prior to placement of the implant, vertebrae are distracted in a manner to provide a desired lordosis between the vertebrae. The pre-distracted vertebrae are then tapped to provide a tapped bore having a geometry matching the conical geometry of the implant. The threaded implant is then placed within the pre-tapped conical bore.
Claims13
A kit for placing an implant into a disk space between opposing vertebrae having opposing end plates to be separated by a predetermined degree of lordosis, said kit comprising:
- (A) an implant having:
- a generally frusto-conical hollow body having:
- a leading end
- a trailing end comprising:
- a trailing end rise
- a terminal end
- a longitudinal axis
- a first taper increasing from said leading end to said trailing end rise;
- and
- a second taper increasing from said terminal end to said terminal end rise
- said first taper of said frusto-conical body having a conical angle approximating said degree of lordosis;
- an implant thread pattern surrounding said body;
- openings formed through a conical wall of said body into an interior of said body with said openings formed at least on diametrically opposite sides of said body;
- said implant thread having a generally flat radial extremity in a surface of a cone defined by said implant thread;
- (B) a tap having;
- a shaft defining a longitudinal axis;
- a tapping head at a distal end of said shaft, said tapping head having a tapping thread surrounding said axis with a thread pattern substantially matching said implant thread pattern;
- said tapping thread includes a plurality of peaks and valleys defining a conical path around said axis with a leading end tap diameter adjacent said distal end and with a trailing end tap diameter spaced from said distal end, said trailing end tap diameter being greater than said leading end tap diameter;
- said leading end tap diameter being substantially equal to said leading end implant diameter.
A kit for placing an implant into a disk space between opposing vertebrae having opposing end plates to be separated by a predetermined degree of lordosis, said kit comprising:
- (A) an implant having;
- a generally frusto-conical hollow body having:
- a leading end
- a trailing end comprising:
- a trailing end rise
- a terminal end
- a longitudinal axis
- a first taper increasing from said leading end to said trailing end rise;
- and
- a second taper increasing from said terminal end to said terminal end rise;
- said first taper of said frusto-conical body having a conical angle approximating said degree of lordosis;
- an implant thread pattern surrounding said body;
- openings formed through a conical wall of said body into an interior of said body with said openings formed at least on diametrically opposite sides of said body;
- said implant thread having a generally flat radial extremity in a surface of a cone defined by said implant thread;
- said implant thread having a generally flat radial extremity in a surface of a cone defined by said implant thread;
- (B) a tap having:
- a shaft defining a longitudinal axis;
- a tapping head at a distal end of said shaft, said tapping head having a tapping thread surrounding said axis with a thread pattern substantially matching said implant thread pattern;
- said tapping thread includes a plurality of peaks and valleys defining a conical path around said axis with a leading end tap diameter adjacent said distal end and with a trailing end tap diameter spaced from said distal end, said tailing end tap diameter being greater than said leading end tap diameter;
- said leading end tap diameter being substantially equal to said leading end implant diameter;
- and
- said tapping thread having a sharp radial extremity.
Dependencies are inferred from the claim text.