Effect of Mixture of Recombinant Human Bone Morphogenic Protein-2 and demineralized Bone Matrix in Lateral Lumbar Interbody Fusion.

Objective: This study aims to determine the optimal dose of recombinant-human Bone Morphogenic Protein-2 (rhBMP-2) for successful bone fusion in minimally invasive Lateral Lumbar Interbody Fusion (MIS LLIF). Previous studies show that rh-BMP is an effective alternative to autologous iliac crest bone graft, but the optimal dose remains uncertain. The study analyzes the fusion rates associated with different rh-BMP doses to provide a recommendation for the optimal dose in MIS LLIF. Methods: 93 patients underwent MIS LLIF using demineralized bone matrix (DBM) or a mixture of rhBMP-2 and DBM as fusion material. The group was divided into the following three groups according to the rhBMP-2 usage. Group A (only DBM was used, n: 27). Group B (1mg of rhBMP-2 per 5cc of DBM paste, n: 41). Group C (2mg of rhBMP-2 per 5cc of DBM paste, n: 25). Demographic data, clinical outcomes, postoperative complication and fusion were assessed. Results: At 12 months post-surgery, the overall fusion rate was 92.3% according to Bridwell fusion grading system. Group B and C, who received rhBMP-2, had significantly higher fusion rates than group A, who received only DBM. However, there was no significant increase in fusion rate when the rhBMP-2 dosage was increased from group B to group C. The group B and C showed significant improvement in back pain and ODI compared to the group A. The incidence of screw loosening was decreased in group B and C, but there was no significant difference in the occurrence of other complications. Conclusion: Usage of rhBMP-2 in LLIF surgery leads to early and increased final fusion rates, which can result in faster pain relief and return to daily activities for patients. The benefits of using rhBMP-2 were not significantly different between the groups that received 1mg/5cc and 2mg/5cc of rhBMP-2. Therefore, it is recommended to use 1mg of rhBMP-2 with 5cc of DBM, taking both economic and clinical aspects into consideration.

Occlusion of Both Vertebral Arteries With Development of Collateral Circulation From the Deep Cervical Artery After Cervical Spine Trauma.

Careful evaluation of vertebral artery injuries is important after cervical translation injuries or transverse foramen fractures. Treatment of trauma can be complicated in cases of concomitant vertebral artery injuries. A 76-year-old woman was admitted to our hospital with left hemiparesis (Motor grade 3) after a motorcycle accident. Cervical spine magnetic resonance imaging (MRI) and computed tomography (CT) revealed a C3 burst fracture and a left C3 lateral mass and lamina fracture. CT angiography revealed fracture fragments that predisposed the vertebral artery to injury throughout its course in the area. CT angiography confirmed that both vertebral arteries were occluded at the C3 fracture site. Subsequent brain MRI revealed acute infarction in the right occipital area. Although both vertebral arteries were occluded, the infarction site did not correspond to the territory supplied by these vessels; therefore, we performed transfemoral cerebral angiography, which revealed collateralization of the bilateral vertebral arteries by the deep cervical artery.. The deep cervical arteries are located between the posterior muscles; therefore, a fixation operation performed using the posterior approach may have affected the collateral circulation and led to exacerbation of the infarction site. Therefore, surgery was performed using an anterior approach and it was possible to minimize the risk of cerebral infarction through preservation of collateral circulation.

Characteristics of PCDDs/PCDFs in stack gas from medical waste incinerators.

Toxic polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in 45 stack gas samples were measured from 19 medical waste incinerators in South Korea using high-resolution gas chromatography equipped with a high-resolution mass spectrometer. The average concentrations of the sum of 17 toxic PCDD/PCDF congeners emitted from the medical waste incinerators ranged from 0.153 to 101.9 ng/Sm3. Based on the World Health Organization toxic equivalency factor, they ranged from 0.007 to 5.437 ng-TEQ/Sm3. The congener patterns of PCDDs/PCDFs were described using principal component analysis and presented four patterns. In the evaluation of annual average total TEQ concentrations, outlying stack gas samples were excluded. In this study, the number of chlorine substitutions was evaluated as an important factor in congener patterns. Coefficient of determination values were employed for evaluation of correlation between PCDDs and PCDFs. 1,2,3,4,6,7,8-HpCDF was measured as the most emitted congener, while 2,3,4,7,8-PeCDF was the greatest TEQ contributor.