INTERVERTEBRAL DISC SPACE SIZING TOOLS AND METHODS

摘要

A method and apparatus make a size measurement within an intervertebral space by placing an expandable and contractable device into the intervertebral space, expanding the device, measuring a size characteristic of the space, contracting the device and then removing it. Preferably, a holder is held by a physician with an obround-shaped device being inserted into the space and then turned by a steering mechanism prior to the device expansion. The device is small enough to be passed through an incision in the disc annulus prior to turning and after contraction. The measurement may be accomplished by an external x-ray or other imaging device imaging the expanded device in situ or by mechanically operated devices. An expansion and contraction mechanism such as fluid containing bladder or mechanically shifted members expands the device which later contracts in a controlled manner to the contracted size.