A new pathological classification of lumbar disc protrusion and its clinical significance.

Lumbar disc protrusion is common. Its clinical manifestations and treatments are closely related to the pathological changes; however, the pathological classification of lumbar disc protrusion is controversial. This article introduces a new pathological classification comprising four types of lumbar disc protrusion according to intraoperative findings. The damage-herniation type is probably caused by injury and is characterized by soft herniation, the capsule can easily be cut and the broken disc tissue blocks overflow or is easily removed. The broken disc substances should be completely removed; satisfactory results can be achieved by minimally invasive endoscopic surgery. The degeneration-protrusion type is characterized by hard and tough protrusions and the pathological process by degeneration and proliferative reaction. The nerve should be decompressed and relaxed with minimally invasive removal of the posterior wall; the bulged or protruded disc often need not be excised. The posterior vertebral osteochondrosis with disc protrusion type is characterized by deformity of the posterior vertebral body, osteochondral nodules and intervertebral disc protrusion. The herniated and fragmented disc tissue should be removed with partially protruding osteochondral nodules. Intervertebral disc cyst is of uncertain pathogenesis and is characterized by a cyst that communicates with the disc. Resection of the cyst under microscopic or endoscopic control can achieve good results; and whether the affected disc needs to be simultaneously resected is controversial. The new pathological classification proposed here is will aid better understanding of pathological changes and pathogenesis of lumbar disc protrusion and provides a reference for diagnosis and treatment.