[The protrusion of thoracic intervertebral disc-thoracic spondylosis (author's transl)].

The protrusion of cervical intervertebral discs was divided into three pathological entities by Spurling; soft disc, hard disc and spondylosis. We applied these concept to the dorsal intervertebral disc disease and treated two cases of thoracic spondylosis. Case 1. A 41-year-old male entered the hospital because of the gradual progression of weakness of both legs of two months' duration. Since ten days before admission he had not had an errection and had not been to able to walk and micturate. He also complained of paresthesia radiating down the abdomen into both legs. There were no visceral complaints. Neurological examination revealed severe weakness of both legs with bilateral impairment of deep sensations and hypalgesia up to the level of T6. Reflexes in both legs were hyperactive with sustained clonus. Plantar responses were extensor bilaterally. Though plain X-rays showed no changes, tomography revealed a calcified intervertebral spur formation at the T5-6 interspace. A myelogram showed a complete block of the contrast medium at the level of the upper part of T6. The patient underwent a complete laminectomy from T3 through T6 and extradural anterior decompression with the removal of the calcified disc at the T5-6 interspace using an air drill. Postoperatively, he demonstrated an immediate improvement in sensation and a gradual recovery in motor power. At his follow-up examination 14 months after surgery he could walk without assistance. Case 2. A 47-year-old dwarfish woman (130 cm) with a low back pain and difficulty in walking for a few years duration was admitted. A few months before admission she felt pain at her left lateral abdomen. There was weakness of both legs, greater in the left. Reflexes in her left lower extremity were hyperactive with sustained clonus. Plantar responces were flexor bilaterally. Palin X-rays showed scoliosis of thoracic spine with the top at T7 level and calcified intervertebral masses at T10-11, T11-12 and T12-L1, extending into the canal that were confirmed more clearly by tomography. Myelography by a cisternal puncture disclosed a complete block at the level of T10. The patient underwent total laminectomy of T9 through L2 and extradural anterior decompression with the removal of calcified discs. At her follow-up examination 12 months after surgery she could walk for herself with some residual neurological signs, minimal weakness in the right leg and hypesthesia up to the level of T12 in the left. We have discussed the incidental, related diagnostic and operative problems of this disease.