腰椎の局在性後縦靱帯骨化症の4例

抄録

Recently, we experienced the treatment of 4 cases with lumbago and sciatica which resulted from nerve root compression by a small ossified fragment of the posterior longitudinal ligament in location of the L4-5 intervertebral space of the lumbar spine.
Radiologically, the ossified fragment was the thin lens-shaped and situated a little apart from the posterior surfaces of the intervertebral space and the vertebral body.
Laminectomy and posterior spinal fusion were performed on 2 cases with severe symptoms. At operation, it was noticed that the ossified fragment was pushed up by the protruded intervertebral disc. Microscopically, it was proved that the ossified fragment was produced by ossifing metaplasia of the posterior ligament.
It is undoubted that localized ossification of this ligament may be closely related to disc degeneration, irritation to the ligament at movements of the lumbar spine and local disposition for ossification. Therefore, it is presumed that this condition may be originally included into early special pattern of spondylosis deformans.