Patent ID: 7914581

Claim:
An expandable medical implant for supporting skeletal structures comprising: a first tubular member with a first connection end and an opposite first skeletal interface end and a first longitudinal axis extending between the first connection end and the first skeletal interface; a second tubular member with a second connection end configured to engage with the first connection end of the first tubular member, the second tubular member having an opposite second skeletal interface end and a second longitudinal axis extending between the second connection end and the second skeletal interface; a key pin non-threadedly fixed to the first tubular member and positioned in a slot extending through the second tubular member from an outer surface to the an inner surface of the second tubular member and extending in a direction parallel to the second longitudinal axis, the slot defining a desired longitudinal path of translation between the first and second tubular members such that the key pin positioned in the slot guides translation between the first tubular member and the second tubular member along the desired path in a direction parallel to the first and second longitudinal axes without relative rotation of the first and second tubular members; wherein the first tubular member includes a first set of adjacent protrusions that are spaced apart from one another by a first distance; and wherein the second tubular member includes a second set of protrusions that are spaced apart from one another by a second distance that is greater than the first distance, wherein one or more of the second set of protrusions interdigitate with one or more of the first set of adjacent protrusions.