Expandable anterior lumbar implants

An expandable implant comprising:

• an upper endplate and a lower endplate configured to engage adjacent vertebrae;
• and
• an actuator assembly extending along a longitudinal axis of the implant and positioned between the upper and lower endplates for expanding the upper and lower endplates to independently control anterior and posterior heights of the implant, the actuator assembly including a moveable anterior actuator receiving and securing a plurality of anterior pivot ramps, a moveable posterior actuator, a stationary posterior actuator engaged with upper and lower posterior pivot ramps, and an actuator screw threaded into an anterior actuator nut located in the moveable anterior actuator, and a posterior actuator nut located in the stationary posterior actuator, wherein the actuator screw threads through the moveable posterior actuator to translate the moveable posterior actuator,
• wherein each anterior pivot ramp has a smooth inner surface to allow each anterior pivot ramp to rotate on the moveable anterior actuator,
• wherein the upper and lower endplates each define a plurality of ramps configured to mate with corresponding ramped surfaces on the anterior pivot ramps and the upper and lower posterior pivot ramps,
• wherein when the actuator screw and the anterior actuator nut are turned together, the moveable posterior actuator moves toward the stationary posterior actuator, forcing the upper and lower posterior pivot ramps outward resulting in parallel expansion of the upper and lower endplates, and when only the anterior actuator nut is turned, the moveable anterior actuator moves alone to increase the anterior height, resulting in an increase in a lordotic angle of the implant.

A method of spinal fixation comprising:

• inserting an expandable intervertebral implant into a disc space between adjacent vertebrae, the expandable implant comprising upper and lower endplates each configured to engage one of the adjacent vertebrae and an actuator assembly extending along a longitudinal axis of the implant and positioned between the upper and lower endplates for expanding the upper and lower endplates to independently control anterior and posterior heights of the implant, the actuator assembly including a moveable anterior actuator, a moveable posterior actuator, a stationary posterior actuator, an actuator screw threaded into an anterior actuator nut located in the moveable anterior actuator, and a posterior actuator nut located in the stationary posterior actuator,
• wherein the actuator screw threads through the moveable posterior actuator to translate the moveable posterior actuator,
• wherein the upper and lower endplates each define a plurality of ramps configured to mate with corresponding male protrusions on the moveable anterior actuator and the moveable and stationary posterior actuators, wherein the male protrusions on the moveable anterior actuator and the moveable and stationary posterior actuators include point contact pivoting ramps defined thereon which act as a pivot point, facilitating pivoting or rotational movement for a lordotic angle adjustment between the upper and lower endplates;
• and
• expanding the implant in height by:
• (1) rotating the actuator screw and the anterior actuator nut together to move the moveable posterior actuator toward the stationary posterior actuator, thereby forcing the upper and lower endplates apart resulting in parallel expansion;
• or
• (2) rotating only the anterior actuator nut to move the moveable anterior actuator alone to increase the anterior height, resulting in an increase in a lordotic angle of the implant.