Effects Of Unilateral Graded Facetectomy On Lumbar Spinal Stability In Biomechanics

Lateral lumbar disc herniation is a special type of lumbar disc hemiation. It means the exerted tissues of intervertebral disc is on inside or out of intervertebral foramen, compressing the nerve root which runs in the same level of intervertebral foramen and producing a series of syndromes. "Lateral" and "non-lateral" are based on the medial border of intervertebral foramen. Lateral lumbar disc hemiation is a special type of lumbar disc hemiation because of the difference with lateral central lumber disc hemiation and central lumbar disc hemiation in anatomy, symptom, imageology, treatment and so on. Lateral lumbar disc hemiation occurs rarely, the incidence rate is about 2.6%-11.7% in all of lumber disc hemiation. The first paper reported by Abdullah in 1974. Reviewing the internal references, the predilection site of lateral lumber disc hemiation is on the level of L4,5 and L3,4(>80%); the next is on the level of L5S1( about 11%). But the common sites of lateral central lumber disc herniation are on L5S1 and L4,5. The reason is unclear. The exerted tissues compress the never root which come from the same level of lumbar disc hemiation because of the exerted tissues being on the anterior-lateral of the never root leaving vertebral canal. Such as the extreme lateral lumber disc hemiation of L4,5 compresses the nerve root of L4. But in lateral central one, the exerted tissues compress the never root of L5. Part of orthopedists can not know these well and lead to missed diagnosis and misdiagnosis. It is the reason of the surgery failure of lumbar disc herniation. The traditional operation influences the stability of vertebral column directly because that it destroys the bone structure severely. We have gotten satisfied therapeutic efficacy in treatment of extreme lateral lumber disc hemiation by X-TUBE since 2003 in our hospital. My experiment was graded facetectomy on lumbar spine from outside to inside by imitating X-TUBE, study the effects of spinal stabilization and provide practice and rationale for operation in clinical. 5 functional spine units(FSU) from 5 adult fresh cadavers without any diseases in lumbar vertebrae were collected. Soft tissues of the samples such as the paraspinal muscles, fats were cut off; the ligaments, articular capsules and the structure...