Objective To evaluate the therapeutic efficacy of microendoscopic tubular retractor system (METRx) with a postmedial approach in the treatment of lumbar disc herniation. Methods A total of 290 patients with lumbar disc herniation were treated with METRx. The duration of follow-up ranged from 3 months to 33 months. Results According to the Nakai scale, 81% (235 cases) of the patients were evaluated as excellent, 13.4% (39 cases) as good, 4.8% (14cases) as fair and 0.7% (2 cases) as poor. Postoperative infection in intervertebral space was found in 2 cases. Conclusions METRx has a satisfactory short-term therapeutic efficacy in the treatment of lumbar disc herniation.

BACKGROUND:Panax notoginseng saponins promotes bone repair by improving vascular proliferation. Therefore, the scaffolds carrying panax notoginseng saponins were supposed to be used to improve bone repair at the bone defect region. However, the biocompatibility of scaffolds remains unclear.
OBJECTIVE:To evaluate the biocompatibility of panax notoginseng saponins-hydroxyapatite/chitosan scaffolds.
METHODS:A new bone repair scaffold has been generated by thoroughly mixtures of 0, 0.1, 1, 10 mg panax notoginseng saponins and chitosan/hydroxyapatite using in-situ composite technique and freeze-drying technique. Morphology and mechanical property of the scaffold were observed under a scanning electron microscope. (1) Cel proliferation test:rabbit bone marrow mesenchymal stem cel s of passage 3 were cultured in four kinds of drug loaded hydroxyapatite/chitosan composite material leaching liquor. Cel s normal y cultured were considered as controls. 3-(4, 5-Dimethylthiazol-2-yl) 2, 5-diphenyl tetrazolium bromide was used to measure absorbance value of cel s in each group. (2) Hemolysis test:Rabbit anticoagulated blood was added with four kinds of drug loaded hydroxyapatite/chitosan composite material leaching liquor. Absorbance values were measured using a microplate reader in each group. (3) Pyrogen test:The four kinds of drug loaded hydroxyapatite/chitosan composite material leaching liquor and saline were respectively injected into ear vein of rabbits, and the increase of rabbit body temperature was detected.
RESULTS AND CONCLUSION:Drug loaded hydroxyapatite/chitosan composite material contained three dimensional porous structure of 110μm in diameter. Drug loading process of panax notoginseng saponins did not significantly affect the porosity, pore size and density of the composite material, but decreased its breaking strength and elastic modulus. The larger amount of drug loading showed a more obvious effect. Simple hydroxyapatite/chitosan composite material had good cel ular compatibility. The composite material after drug loading obviously suppressed cel proliferation, and the larger amount of drug loading showed a more obvious effect. The composite material had good blood compatibility before and after drug loading. The composite material had good pyrogen effects before and after drug loading, but accorded with acceptable quality level of pyrogen test.