Parasyndesmophytes or floating syndesmophytes are, as the name suggests, paravertebral dystrophic soft tissue calcifications or heterotopic ossifications.
They are known to be seen in :
Initially they begin at a distance from the vertebral body and intervertebral space. In early disease they are best described as thick and fluffy or thin and curvilinear densities on one side of the spine, paralleling lateral surface of vertebrae and disci. Eventually they will grow to form large and bulky masses, merging with the underlying bone and disc.