Curved expandable cage

An expandable implant for insertion into an intervertebral space between a superior vertebral body and an adjacent inferior vertebral body, the expandable implant comprising:

• a superior endplate having a superior outer surface configured to contact the superior vertebral body;
• an inferior endplate having an inferior outer surface configured to contact the inferior vertebral body;
• an actuation member disposed at least partially between the superior and inferior endplates, the actuation member having a first threaded section extending along a first central longitudinal axis of the actuation member and a second threaded section joined to the first threaded section and extending along a second central longitudinal axis of the actuation member, wherein the first central longitudinal axis and the second central longitudinal axis form an angle between about 15° and about 75°;
• a first wedge member threadedly mated with the first threaded section and a second wedge member threadedly mated with the second threaded section;
• wherein the actuation member is configured to be rotated about the first and second central longitudinal axes, thereby driving the first wedge member to translate along the first threaded section and the second wedge member to translate along the second threaded section, such that at least one of the inferior and superior endplates is urged to move away from the other of the inferior and superior endplates from a collapsed implant configuration to an expanded implant configuration, and
• wherein the actuation member comprises a dual universal joint located between the first threaded section and the second threaded section, the dual universal joint comprising a central narrow, circular flange.