Experimental Study The Dura Gide To Annulus Fibrosus Closurement And Evaluate The Efficacy

Objective: To determine the efficacy of an dura gide to facilitate anular defect closure and anular functional recovery after anulotomy and partial discectomy, the repair efficacy was evaluated through biomechanical test and histology test and MRI. The lumbar disc herniation is prevalent in 90% of those over 60 years of age. And the surgical procedure is most important eradicative treatment for it. The discectomy as a common surgical procedure has less complication and much safety for patient, and the medical cost is much lower than fusion operation. While during the discectomy the damage of anular fibrosus usually get treated and may even further aggravate existing damage, That is a reason of reherniation after discectomy. Because the aggravated damage on annular fibrosus, some patients get transient low back pain. So during the discectomy the annular fibrosus should be repaired, that is a crucial method to reduce the reherniation rate and elevate the long term satisfactory rate of treatment. During last decade with the development of resorbable biomaterial and tissue engineer technique, the research on the repair of annular fibrosus and function recovery has been much more intensive than before. Review the previous study on this topic, the major techniques include: surgical annulus closure techniques, cell therapy, gene therapy , tissue engineering with scaffolds, and the combine of cell gene with scaffolds. There are many difficulties on the repair and regeneration of anular fibrosus such as follows: A: there is no appropriate annular cell used for annular fibrosus tissue engineering, there is no appropriate culture medium that can induce the cell differentiate into normal annular fibrosus cell. B\ In order to develop suitable scaffolds for tissue engineering, AF scaffolds must meet these specific requirements: a: Fill and/or repair the AF gap to contain the NP; b: Allow fixation to the surrounding structures, i.e.endplates and/or surrounding AF tissue; c: to maintain/restore the mechanical properties and stability of a spinal motion segment; d\ Not irritate or adhere to the perineurium. D: the scaffold or repairer must be fixed well with local constructure. The repair and reconstruction of annular fibrosus is a ideal strategy to prevent reherniation and other complication. In date The real challenge, however, might be the development of strategies that deal with the damaged annular fibrosus, how to repair the annular fibrosus, regenerative therapies of the AF should always be accompanied by a clear vision for future clinical application. The objective of our study is to explore an appropriate material and method to repair annular fibrosus, in order to postpone the degeneration of annular fibrosus, elevate the long term satisfactory rate of surgical treatment.Methods: 8 Skeleton mature grown-up local goat were obtained in this study, 4 of them are male and the other 4 are female, body weight were ranged from 15 to 20 Kg, 2-3 years old. All the animals were raised in separated cages, they are all grade 1 animal, average animal. After a good preparation, all the animals have no food and water about 24 hours later, and got general anesthesia through injection muscle. Using standard sterile techniques, the disc spaces of L2–3, L3–4, and L4–5were exposed using a left lateral retroperitoneal approach, the iliopsoas were passive separated from transverse process, and the anterolateral of L2–3, L3–4, and L4–5 disc got well exposed. Three levels were assigned to either: no additional procedure, excise annulus make a gap about 5×10mm alone as control group, or excise annulus followed by placement of an dura gide. After operation, penicillin was prophylactic injected for 4 days, at 12 days after surgery the suture was removed. At 12 weeks after surgery all the animals were killed by aeroembolism, the lumbar spine of all the goats were harvested. Before harvesting the specimen, all the goats were randomly divided in to group 1 and group 2. Group 1 were prepared for biomechanical test, group 2 were prepared for histology and MRI. Get T1, T2 weighted coronal and sagittal image of All the specimen of group 2. after decalcification and dehydration, Sections were cut, polished (to an approximate thickness of 5 um), and mounted to a slide, and stained with Masson and HE.Results: MRI images, and histology indicate that there was an exuberant tissue response at dura gide-treated levels. New tissue formation in dura gide-treated specimens was integrated well with the native anulus, but did not resemble the organization of native anulus. The extent of anular closure was substantial enough to allow the disc a functional recovery to a mean 76.4% of its capacity to develop internal pressure. MRI images indicate that dura gide-treated levels did not maintain signal intensity comparable to exposure-only (intact) levels, but dura gide-treated discs were statistically significantly higher than anulotomy-only levels.Conclusion: Dura gide treated discs were better able to maintain hydration and resulted in a functional recovery relative to anulotomy alone levels. The dura gide reduced the cascade of functional degeneration that an intervertebral disc undergoes following anulotomy.