Objective To evaluate the chnical effect of posterior decompression and shortsegment pedicle instrumentation treating for thoracolumbar fracture with neurologic deficits in different time intervals.Methods Seventy-nine cases of thoracolumbar fracture with neurologic deficits were treated with shortsegment pedicle instrumentation combined with decompression according to the injury and surgery patients with injury of different time interval were divided into ≤24 h group (41 cases) and ＞ 24 h group (38 cases),the curative effect was evaluated by imaging and nerve function recovery.Results Postoperative hospital stay were performed X-ray check,10-14 d after hospital discharge,were primary healing of incision.A total of 79 patients with thoracolumbar fracture combined with neurologic deficits were followed up for 23.5 (15-32) months averagely.Did not appear in the source sex procedure for postoperative infection,nerve injury and postoperative spinal cord injury aggravated phenomenon,not implants rupture,bending and screw loose phenomenon.There was significant difference at 3 d postoperative and the last follow-up in the rate of vertebral compression,cobb' s angle and spinal canal stenosis rate in two groups [≤ 24 h group:(7.9 ± 4.2)％,(8.5 ± 5.0)％ vs.(40.8 ± 8.4)％ and (3.9 ± 2.5)°,(4.2 ± 2.6)° vs.(28.1 ± 13.1)° ; ＞ 24 h group:(8.8 ± 4.8)％,(9.2 ± 4.8)％ vs.(41.7 ± 7.6)％ and (5.3 ± 2.6)°,(5.7 ± 2.7)° vs.(27.6 ± 12.1)°] (P ＜ 0.05),but there was no statistically significant difference between two groups (P ＞ 0.05).The stenosis rate in two groups at 3 d postoperative was obviously better than preoperative[≤24 h group:(5.3 ± 1.5)％ vs.(41.4 ± 6.1)％; ＞ 24 h group:(6.8 ± 1.1)％ vs.(40.5 ± 5.4)％] (P ＜ 0.05),and ≤ 24 h group was superior to ＞ 24 h group,there was significant difference (P ＜ 0.05).At the last follow-up,the neurological function with ASIA grade 1-2 level recovery,≤24 h group mean improved 1.4 level,and ＞ 24 h group mean improved 1.2 level.Conclusion The opertion of pedicle instrumentation combined with decompression with nerve function damage can rebuild spinal stability,favorable neural functional recovery.

Objective To compare the clinical outcome of shape memory alloy (SMA) embra-cing fixator and reconstruction plate fixation in treatment of displaced or comminuted midshaft clavicle fractures. Methods There were 65 patients with displaced or comminuted midshaft clavicle fractures surgically treated with either a SMA embracing fixator or a reconstruction plate. The patients were divided into two groups according to fixation methods, ie, SMA embracing fixator group (30 patients at average age of 28.1 years) and reconstruction plate group (35 patients at average age of 26.1 years). All pa-tients were followed up for mean 12 months and shoulder function was evaluated using shoulder score. Results Compared with reconstruction plate group, SMA embracing fixator had shorter operation time, smaller wound incision and less loss blood (all P < 0.05). However, there was no statistical difference in aspects of hospital stay, cost, JOA shoulder score and bone union rate between two groups (all P > 0.05). Conclusion The internal fixation with SMA embracing fixator is better than reconstruction plate fixation in treatment of midshaft clavicle fractures.

Objective To observe the effect of vascular endothelial cell growth factor (VEGF)on apoptosis and matrix metabolism of rat intervertebral.disc cells cultured in vitro. Methods Culture system of rat intervertebral disc cells was established to culture the monolayer intervertebral disc cells in vitro.The well-grown intervertebral disc cells of the second generation were chosen and anti-Fas antibody was applied to induce their apoptosis.Then,VEGF at different concentrations ( 10,100,1 000 μg/L)were used to affect their apoptosis and metabolism.The apoptosis of the cells stained with Propidium Iodide (PI) was detected by using flow cytometry.The levels of hydroxyproline and proteoglycan in the culture medium were detected by using chloramines T method and DMB chromometry method,respectively.Results ( 1 ) The apoptotic ratio of the intervertebral disc cells affected by different concentrations of VEGF (10,100,1 000 μg/L) was (87.62 ±11.06)％,(53.30 ±9.23)％ and (16.75 ±4.21)％ respectively,with significant differences in comparison with the control group (P ＜ 0.01 ).(2)The contents of hydroxyproline [ (6.71 ±0.33) μg/L,(9.12 ±0.41 ) μg/L,( 11.58 ±0.12) μg/L] and proteoglycan [ (23.21 ± 2.87) μg/L,( 32.45 ± 5.23 ) μg/L,(37.18 ± 3.22) μg/] in the culture medium raised with the increase of VEGF concentration ( 10,100,1 000 μg/L),with statistical differences compared with those of the control group (P ＜0.01 ).The contents of hydroxyproline and proteoglycan were positively correlated with the concentration of VEGF (ra=0.972,P＜0.01;rb =0.907,P＜0.01). Conclusion VEGF can inhibit the apoptosis of the rat intervertebral disc cells cultured in vitro and promote collagen and proteoglycan synthesis of the cell matrix.