BACKGROUND: Resection of the nudeus pulposus is the classical treatment for intervertebral disc protrusion, except a higher recurrence rate. OBJECTIVE: To verify the feasibility of establishing an animal model of intervertebral disc degeneration by puncture and aspiration via a posterolateral approach to simulate resection of human nucleus pulposus. DESIGN, TIME AND SE'I'FING: The experiment was conducted in the animal Experimental Center of Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from October 2006 to February 2007. MATERIALS: Twenty Japanese big ear rabbits were selected to establish animal models of intervertebral disc degeneration. METHODS: Some nucleus pulposus tissues were abstracted from the L1-2 and L3-4 segment of 20 rabbits by the puncture and aspiration method using a 21-gaege hypodermic needle. Histological analysis was performed at 2, 4, 8, 12 weeks after surgery, and L2-3 segment was used as control group.MAIN OUTCOME MEASURE: Histological structure of the intervertebral disc was observed by homatoxylin-eosin staining. RESULTS: Hematoxylin-eosin staining revealed a great deal of complete nudeus pulposus tissues, clear boundaries between nucleus pulposus and annulus fibrosus in the control group, and the structure of near normal annulus fibrosus was almost normal, nucleus pulposus tissue had a large number of nucleus pulposus cells. In the experimental group, the nucleus pulposus cell reduced in amount in the fourth week, the nucleus pulposus at the twelfth week were mainly full of flbroblests, while few nucleus pulposus cells were found.CONCLUSION: It is successful to establishing an animal model of intervertebral disc degeneration by puncture and aspiration via a posterolateral approach based on simulating the resection of human nucleus pulposus. This model is available for repairing intervertebrai disc degeneration using tissue engineering techniques.

10.3969/j.issn.2095-4344.2013.24.002

BACKGROUND:Studies have shown that low-intensity and short-time vibration with a certain frequency can reduce the absorption of bone tissue and increase the quantity and quality of bone through promoting the proliferation and differentiation of osteoblasts.
OBJECTIVE:To investigate the effects of different frequencies of vibration strains on cycle, proliferation and differentiation potency of RAW264.7 cel s cultured in vitro.
METHODS:Passage 6 RAW264.7 cel s in good conditions were randomly divided into six groups, and each group was induced cultured with Dulbecco’s modified Eagle’s medium containing receptor activator of nuclear factor kappa B ligand. The final concentration of receptor activator of nuclear factor kappa B ligand was adjusted to 50μg/L, and then kept without changes. The non-loading group did not loaded with vibration strain, and the other five groups were loaded with 3-10 Hz, 15-35 Hz, 35-45 Hz, 50-70 Hz and 70-90 Hz vibration strains on the RAW264.7 cel s respectively. The other vibration parameters were consistent;the vibration time was 15 min/time with the vibration intensity of 0.3 g, twice per day. The cel cycle and cel proliferation were detected at 3 and 6 days after loading of vibration strains.
RESULTS AND CONCLUSION:After composite vibration loading for 6 days, the cel cycle phase in the vibration groups was changed to some extent when compared with the non-loading group. Compared with non-loading group, the cel number in the G 1 phase of the vibration group was significantly increased (P<0.01);the cel number in the S phase and G 2+M phase of the vibration group was significantly decreased (P<0.01);the vibration parameters in the vibration group were significantly decreased (P<0.01). The results indicate that different frequencies of vibration strains can affect the cel cycle and proliferation, and can inhibit the proliferation and differentiation of osteoblasts.

Objective: To evaluate the effects of parallel versus perpendicular double plating for distal humerus fracture of type C. Methods: A standardized comprehensive literature search was performed by PubMed, Embase, Cochrane library, CMB, CNKI and Medline datebase.Randomized controlled studies on comparison between parallel versus perpendicular double plating for distal humerus fracture of type C before December 2015 were enrolled in the study.All date were analyzed by the RevMan 5.2 software. Results: Six studies, including 284 patients, met the inclusion criteria.There were 155 patients in perpendicular double plating group, 129 patients in parallel double plating group.The results of Meta-analysis indicated that there were statistically significant difference between the two groups in complications (OR=2.59, 95%CI: 1.03 to 6.53, P=0.04). There was no significant difference between the two groups in surgical duration (MD=-1.84, 95% CI: -9.06 to 5.39, P=0.62), bone union time (MD=0.09, 95%CI: -0.06 to 0.24, P=0.22), Mayo Elbow Performance Score (MD=0.09, 95%CI: -0.06 to 0.24, P=0.22), Range of Motions (MD=-0.92, 95%CI: -4.65 to 2.81, P=0.63) and the rate of excellent and good results (OR=0.64, 95%CI: 0.27 to 1.52, P=0.31). Conclusion Both perpendicular and parallel double plating are effective in distal humerus fracture of type C, parallel double plating has less complications.