SELECTION OF SURGICAL APPROACH TO TREAT TRAUMATIC INSTABILITY OF SUBAXIAL CERVICAL SPINE

Objective To evaluate the clinical outcomes of surgical therapy in treating traumatic instability of subaxial cervical spine through either anterior or posterior approach. Methods According to the Allen-Fergurson's classification, we retrospectively studied 42 cases of traumatic instability of subaxial cervical spine through either anterior or posterior surgical reconstruction. Patients requiring approach for either reduction or decompression were not included. Results The average follow-up interval was 3 years and 2 months. The anterior and posterior reconstructions were 24 and 18 cases, respectively. Before operation, the average scores of JOA and VAS were: 12.1 and 6.9 for anterior group, and 12.3 and 7.2 for posterior group. At the final assement, the scores of JOA and VAS improved to 16.0 and 2.2 for anterior group, and 15.7 and 2.6 for posterior group. The average ASIA motor scores of anterior and posterior group improved to 68.2 and 65.5 at the final follow-up from 58.4 and 59.7 before operation, respectively. The ASIA grade (A-E) was converted to a numeric score. The average scores before operation in the anterior and posterior group were 3.3 and 3.4, and increased to 3.8 and 3.7 at the final follow-up. After operation, there were different extent improvements of average radiological parameter, such as Cobb angle, vertebral body translation and disc height ratio. The average operation time and blood losing were 122 min and 125 mL for anterior group, and 153 min and 287 mL for posterior group. Fusion was achieved in all patients and 4 and 2 complications occurred at the anterior or posterior group. Conclusion The results showed that there were no obvious difference in parameters, such as neurological assements, functional grades, fusion rate, operation time and blood losing, between anterior and posterior group, except the virtues of anterior group in reconstruction and maintaining physiologic cervical lordosis and intervertrbal disc height occurred.

Pollen-based Holocene quantitative temperature reconstruction on the eastern Tibetan Plateau using a comprehensive method framework

Quantitative climate reconstruction on long timescales can provide important insights for understanding the climate variability and providing valuable data for simulations. Unfortunately, the credibility of some attempts was hampered by incomplete reconstruction procedures. We here establish a comprehensive framework resting on high-quality Chinese modern pollen database, including modern pollen data screening, calibration set selection, major climate factor analysis, appropriate model selection, strict statistical assessment of results and ecological interpretation. The application of this framework to three high-resolution pollen records from the eastern Tibetan Plateau allows accurate quantitative inferences of Holocene temperature changes, which is the major control of regional vegetation. The results show that the mean warmest month temperature(MTwa)during the early Holocene was ca. 10.4℃ and reached the highest value at 8.5–6 ka BP(ca. 11℃). The early and mid-Holocene(11–5 ka BP) warmth was followed by 1.2℃ temperature decrease, culminating in the coolest temperatures of the Holocene during the Neoglacial cooling. Superimposing on the general cooling trend, MTwareveals a significant 500-yr periodicity with varying intensities through time, showing that warm(cold) intervals are in phase with solar maxima(minima) periods. This spectral similarity indicates a possible connection of multi-century scale climate fluctuations with solar forcing.