There is osteoarthrosis of the interspinous joint secondary to dessication and loss of intervertebral disc space (Baastrup's disease). There will also be narrowing of the exit foramina bilaterally, resulting in back pain and radicular pain. Spinal claudication (pain after walking a certain distance) is present.

This is condition may be delayed or treated with placement of interspinous devices.

The location of the spinous processes under the skin allows for the implantation of interspinous process spacers with minimal operative intervention and unwanted after effects of surgery. The interspinous process devices are designed to distract (open) the foramina, where the nerve roots traverse. These devices may also reduce the axial load on the intervertebral disc.

Below are images of 4 interspinous devices (clockwise from upper left quadrant: the coflex, DIAM, Wallis and X-Stop.