ABSTRACT
Objective:To investigate the effectiveness and safety of middle-column preserved pedicle subtraction closing-opening wedge osteotomy for the treatment of stiff kyphosis.Methods:From January 2016 to April 2018, 12 patients with stiff kyphosis in our department were treated with middle-column preserved pedicle subtraction closing-opening wedge osteotomy. The patients' operative time, intraoperative blood loss, postoperative drainage, surgical complications, low back pain and leg pain visual analogue scale (VAS), Oswestry dysfunction index (ODI) score, and SF-36 were recorded.These parameters were compared at preoperative, postoperative, and at the final follow-up. Coronal parameters included lumbar scoliosis Cobb angle, C 7 vertebral body center to humeral vertical line distance (C 7PL-CSVL), whilesagittal parameters includedlumbar Lordosis (LL), sacral slope (SS), pelvic tilt (PT), and sagittalvertical axis (SVA). Results:All of 12 patients successfully completed the operation.The mean operation time was 238.20±65.95 min, the mean intraoperative blood loss was 440.50±133.60 ml.The patients’ODI score was 65.92%±6.96% at the preoperative, and 21.00%±3.19% at the final follow-up. The difference was statistically significant ( t=20.32, P<0.0001).The VAS score of back pain was 6.00±0.95 at preoperative, 2.33±0.89 at 3 months postoperatively, and 1.42±0.51 at the final follow-up. The VAS score of leg pain was 6.91±1.24 at preoperative, 2.50±1.00 at 3 months postoperatively, and1.50±0.52 at the final follow-up. There was significant difference in SF-36 at preoperative and at final follow-up ( P<0.05). The differences in LL, SS, PT and SVA at the preoperative and at final follow-up were statistically significant ( F=17.47, P<0.001; F=5.015, P=0.0125; F=14.66, P<0.001; F=81.11, P<0.001) . There was significant difference in lumbar scoliosis Cobb angle and C 7PL-CSVL at the preoperative and at final follow-up ( F=87.19, P<0.001; F=100.9, P<0.001) . Conclusion:The advantages of this surgical procedure includesimple operation, reducedsurgery time, and shorten intraoperative bleeding, which can effectively relief clinical symptoms, improve the quality of life, correctkyphosis, and maintain the patient's spinal-pelvic balance.
ABSTRACT
<p><b>OBJECTIVE</b>The aim of this study was to determine the level of exposure of mercury (Hg) miners and smelter workers to elemental mercury (Hg(0)) vapor in China, who work in Hg mines without using protective equipment against Hg(0) vapor. In addition, the level of methylmercury (MeHg) intake by the workers was estimated from the MeHg concentration in their hair.</p><p><b>METHODS</b>Urinary total mercury (THg) and hair THg and MeHg concentrations were measured in 26 Hg miners and smelter workers (i.e., exposed group), and 48 unexposed people (unexposed group).</p><p><b>RESULTS</b>The exposed group showed high geometric mean THg concentrations in urine (258 ng/ml, 226 μg/g creatinine) and hair (20.0 μg/g). The urinary THg concentration of the smelter workers in particular was extremely high (338 μg/g creatinine in urine). The highest urine THg concentration reached 4577 μg/g creatinine. THg concentrations in urine and hair showed a significant correlation in the exposed group (r=0.62), indicating the adhesion of Hg(0) vapor to hair. However, no such significant correlation was found in the unexposed group. Hair MeHg concentration in the exposed group (1.97 μg/g) was about threefold higher than that in the unexposed group (0.60 μg/g).</p><p><b>CONCLUSIONS</b>This study shows that smelter workers in a Chinese Hg mine are exposed to extremely high levels of Hg(0) vapor, and that Hg miners are exposed to higher levels of MeHg than the unexposed subjects. Further study is needed to determine the cause of the higher hair MeHg concentration in the exposed group.</p>
ABSTRACT
Objective: The aim of this study was to determine the level of exposure of mercury (Hg) miners and smelter workers to elemental mercury (Hg0) vapor in China, who work in Hg mines without using protective equipment against Hg0 vapor. In addition, the level of methylmercury (MeHg) intake by the workers was estimated from the MeHg concentration in their hair. Methods: Urinary total mercury (THg) and hair THg and MeHg concentrations were measured in 26 Hg miners and smelter workers (i.e., exposed group), and 48 unexposed people (unexposed group). Results: The exposed group showed high geometric mean THg concentrations in urine (258 ng/ml, 226 μg/g creatinine) and hair (20.0 μg/g). The urinary THg concentration of the smelter workers in particular was extremely high (338 μg/g creatinine in urine). The highest urine THg concentration reached 4577 μg/g creatinine. THg concentrations in urine and hair showed a significant correlation in the exposed group (r=0.62), indicating the adhesion of Hg0 vapor to hair. However, no such significant correlation was found in the unexposed group. Hair MeHg concentration in the exposed group (1.97 μg/g) was about threefold higher than that in the unexposed group (0.60 μg/g). Conclusions: This study shows that smelter workers in a Chinese Hg mine are exposed to extremely high levels of Hg0 vapor, and that Hg miners are exposed to higher levels of MeHg than the unexposed subjects. Further study is needed to determine the cause of the higher hair MeHg concentration in the exposed group.