BACKGROUND:Bone marrow mesenchymal stem cels are non-hematopoietic stem cels from the bone marrow and can differentiate into chondrocytes, osteocytes and adipocytes under different induction conditions, which are the most promising seed cels for tissue engineering.
OBJECTIVE:To evaluate the osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cels under directional induction.
METHODS:Bone marrow samples from Japanese rabbits were extracted asepticaly to isolate and purify bone marrow mesenchymal stem cels using density gradient centrifugation and cel adherent method. Then, the cels were cultured in osteogenic and adipogenic induction media as experimental group. Another cels cultured in DMEM medium acted as control group. Sudan IV staining, Von Kossa staining and alkaline phosphatase activity detection were performed at different time after culture to compare the osteogenic and adipogenic rates.
RESULTS AND CONCLUSION:After 7 days of adipogenic induction, smal lipid droplets were visible and the cels arranged disorderly; at 21 days of induction, see lipid droplets with high refractivity were seen in the cytoplasm. Sudan IV staining showed that there were a large amount of red lipid droplets in the cloning center of bone marrow mesenchymal stem cels, but only 5% bone marrow mesenchymal stem cels differentiated into adipocytes in the control group. At 7 days of osteogenic induction, induced cels were confluent in a flagstone shape, and there were many nodules; at 14 days of culture, the center of brown mineralized nodules were visible; at 21 days of culture, smal pieces of mineralized nodules formed. The osteogenic and adipogenic rates were 40% and 20% in the experimental group, respectively, which were higher than those in the control group (5%, 5%). These findings indicate that under certain conditions, bone marrow mesenchymal stem cels can partialy differentiate into fat cels part, and another part differentiate into osteocytes, suggesting there is a certain link between them, that is, more adipocytes and fewer osteoblasts, or vice versa.

BACKGROUND:Humeral fractures can be treated by using rotary self-locking intramedulary nail. The previous spin in self-locking intramedulary nail has some limitations in application, so it should be improved in its design so as to obtain better biomechanical effect.
OBJECTIVE:To improve the design of the rotary self-locking intramedulary nail of the humerus, and to analyze its biomechanical characteristics and application effect, and to provide reference for the clinical treatment of humeral fractures.
METHODS: (1) The design of the rotary self-locking intramedulary nail was improved and tested by mechanics test. (2) A total of 63 cases of humeral fractures were randomly divided into two groups: control group (31 cases) and experimental group (32 cases). Patients in the control group received conventional rotary self-locking intramedulary nail, and patients in the experimental group received improved nail.
RESULTS AND CONCLUSION:Results of mechanical test concerning anti-axial compression, tensile, torsion and bending were obviously better after improvement than before improvement. No significant difference in range of motion was detected between the two groups (P > 0.05). Compared with that before treatment, the range of motion was significantly increased after treatment in both groups (P < 0.01 orP < 0.05). The range of motion was significantly higher in the experimental group than in the control group (P < 0.05). Simultaneously, the excelent and good rate was significantly higher in the experimental group than in the control group (P < 0.05). Thesedata suggest that the improved rotary self-locking intramedulary nail has better mechanical characteristics and can obtain better clinical effect.

BACKGROUND:At present, humeral fractures can be mainly treated by antegrade screwed intramedul ary nail and traditional interlocking intramedul ary nail, but above methods easily induce rotator cuff injury. Results of relevant study revealed that retrograde intramedul ary nailing can solve the above problems. OBJECTIVE:To analyze biomechanical test results of retrograde improved screwed nail and to provide a basis for the further clinical use. METHODS:(1) According to the anatomical characteristics of the human humerus, specimens of humerus were subjected to biomechanical test. (2) A total of 80 cases of humeral fractures were selected from the Orthopeadic Surgery of Xi’an Red Cross Hospital Affiliated to Xi’an Jiaotong University School of Medicine from December 2013 to January 2015. Patients were randomly divided into improved nail group and prototype nail group (n=40), which were given improved nail and prototype nail, respectively. RESULTS AND CONCLUSION:(1) Anti-axial compression, anti-tension, anti-torsion, and anti-bending functions were significantly better in the improved screwed nail than in the prototype nail (P<0.05). (2) The excel ent and good rate of clinical curative effects was significantly higher in the improved nail group than in the prototype nail group. No infection, metal fracture or internal fixation loosening occurred in al patients of the two groups. These findings suggest that compared with traditional screwed nail, retrograde improved screwed nail had more advantages, more reasonable biomechanical design, more simple operation, and lower incidence of complications, so it is fit for clinical application.

BACKGROUND:Elderly patients are more prone to unstable and osteoporotic fractures. In the clinical surgical treatment, different programs can be taken. Internal fixation was done previously. However, the precise choice of the methods of unstable and osteoporotic femoral fractures in the elderly was stil controversial.
OBJECTIVE:To investigate the clinical effect of carbon-coated artificial femoral head replacement in the treatment of elderly patients with unstable and osteoporotic femoral fractures.
METHODS:A retrospective analysis was performed in the Honghui Hospital Affiliated to Health Science Center, Xi’an Jiaotong University from February 2013 to February 2014 in 83 cases of unstable and osteoporotic femoral fractures. These patients were divided into control group (42 cases) and observation group (41 cases) according to treatment methods. Conventional internal fixation and artificial femoral head replacement were conducted. Operation time, intraoperative blood loss, postoperative bed time and hospital stay were observed in the two groups. Patients were fol owed up for 12 months. Recovery of hip function and complications were observed and compared between the two groups.
RESULTS AND CONCLUSION:No significant difference in operation time and intraoperative blood loss was detected between the observation group and the control group (P>0.05). Postoperative bed time and hospital stay were significantly shorter in the observation group than in the control group (P<0.05). The excel ent and good rate of hip joint function was significantly higher in the observation group than in the control group, but the complication rate was significantly lower in the observation group than in the control group (P<0.05). These findings suggest that carbon-coated artificial femoral head replacement for unstable and osteoporotic femoral fractures in the elderly obtained good repair effects, had smal injury to the patient and less complications. Moreover, it can better improve hip function.

Objective To investigate the diagnostic accuracy factors for CT-guided percutaneous biopsy of spine lesions.Methods The clinical and pathological data of 128 patients who were undergone CT-guided percutaneous biopsy of spine lesions were collected.The multivariate stepwise Logistic retrospective study was performed to study the influence of the patient-related factors (sex,age),lesion-related factors (location,bone destruction characteristics,with or without necrosis,with or without calcification),and procedure factors (punc-ture target spot,tissue specimen size)on the diagnostic accuracy.Results The diagnostic accuracy rate of CT-guided percutaneous biopsy of spine lesions was 86.7% (1 1 1/128 ).By multi-factor analysis,bone destruction characteristics (OR = 3.428,P = 0.038 ),with or without necrosis (OR=0.1 93,P =0.012),with or without calcification (OR=0.266,P =0.036),tissue specimen size (OR=0.200, P =0.01 5)were incorporated into the regression equation of the diagnostic accuracy.Conclusion CT-guided percutaneous biopsy of spine lesions has a high diagnostic accuracy.Bone destruction characteristics,with or without necrosis,with or without calcification, tissue specimen size are the independent factors.

Objective The study aimed to identify risk factors of lumbar disc herniation in patients after decompression,and provide theoretical basis for postoperaive rehabilitation.Methods A told of 169 patients with lumbar spinal stenosis underwent bilateral partial laminectomy were included in the study,24 patients in herniation group,and 145 patients without develop postoperative acute sciatica as a control group.The radiographic variables were measured.The threshold of risk factors was evaluated by multiple logistics analysis and receiver operating characteristic curve(ROC) analysis.Results The results revealed that preoperative retrolisthesis during extension was the independent risk factor for lumbar disc herniation(1.24,95％CI[1.07～1.43];P<0.01).The area under the curve(AUC) was 0.801,and the cutoff value was 6.89％.Conclusion The preoperative retrolisthesis was the risk factor of lumbar disc herniation.

Objective To investigate the relationship between the level of serum triglyceride and early pain after posterior lumbar interbody fusion.Methods A total of 79 patients who were admitted into our hospital from March 2016 to December 2016 were selected into the study,and these patients were divided into two groups according to the degree of pain which means 32 cases in the minor pain group and 47 cases in the intermediate pain group.The difference of serum triglyceride level 3 days after operation were compared between the two groups.Pearson correlation analysis was performed to test the correlation between the level of serum triglyceride and early post-surgical pain.Logistic regression analysis was performed to test the risk factors for early post-surgical pain.Results The data indicated the level of pain was significant higher in the intermediate pain group than that of the minor pain group.Level of serum triglyceride had a significantly positive correlation with the level of post-surgical pain and it was the risk factor of pain after posterior lumbar interbody fusion.Conclusion The level of serum triglyceride is the risk factor of early post-surgical pain of lumbar single level interbody infusion,and it should be adjusted in the perioperative treatment.

Objective To investigate the effect of intravenous tranexamic acid (TXA) on perioperative hidden blood loss in percutaneous pedicle screw fixation for thoracolumbar fractures.Methods A prospective study was conducted in the 113 patients who would be subjected to percutaneous pedicle screw fixation for thoracolumbar fracture from January 2017 to December 2017.They were randomly assigned into an observation group (n =58) receiving intravenous drip of 15 mg/kg TXA 30 minutes preoperation or a control group (n =55) receiving intravenous drip of normal saline solution 30 minutes preoperation.The total blood loss and hidden blood loss 24 hours postoperation,D-dimer volume,incidences of deep vein thrombosis and other complications were recorded and compared between the 2 groups.Results There were 54 patients in the observation group and 50 patients in the control group for statistic analysis.The observation group had significantly less total blood loss (319.0 ± 140.5 mL) and hidden blood loss (242.0 ± 143.4 mL) 24 hours postoperation than the control group (418.7 ± 188.1 mL and 354.7 ± 181.9 mL,respectively) (P ＜ 0.05).There were no significant differences between the 2 groups in operation time or intraoperative blood loss (P ＞ 0.05).The volume of postoperative D-dimer was significantly higher than the preoperative value in both groups (P ＜ 0.05).No thromboembolic events occurred in either group.Conclusion Intravenous TXA may significantly reduce intraoperative hidden blood loss with no increased rik of thromboembolic events in percutaneous pedicle screw fixation for thoracolumbar fractures.

Objective To compare minimally invasive percutaneous pedicle screw fixation and open pedicle screw fixation for neurologically intact thoracolumbar fractures.Methods A retrospective study was conducted in the 180 patients who had been treated for thoracolumbar fractures without neurological deficits from January 2016 to December 2016.Of them,93 were treated by minimally invasive percutaneous pedicle screw fixation and 87 by open pedicle screw fixation.The 2 groups were compared in terms of blood loss,radiological parameters,visual analogue scale (VAS) and Oswestry disability index (ODI).Results Compared with the open surgery group,the minimally invasive surgery group had significantly shorter operating time (95.8 ±33.4 min versus 106.3 ±30.9 min),significantly less intraoperative blood loss (65.8 ±40.3 mL versus 183.1 ± 77.5 mL),significantly less total blood loss in theory 24 hours after surgery (374.7 ± 160.6 mL versus 614.8 ± 242.6 mL) and significantly shorter hospital stay (5.2 ± 2.0 d versus 6.7 ± 2.7 d),but significantly longer C-arm exposure time (23.6 ±4.2 min versus 12.4 ±4.1 min) and significantly more hidden blood loss 24 hours after surgery (308.9 ± 159.0 mL versus 243.5 ± 195.5 mL) (P ＜ 0.05).Compared with preoperation,significant improvements were observed at one week postoperation and the last follow-up in the 2 groups regarding the percentage of anterior height of the fractured vertebral body and cobb angle (P ＜ 0.05),but there were no significant differences in the percentage of anterior height of the fractured vertebral body or cobb angle between the 2 groups at one week postoperation or at the last follow-up (P ＞ 0.05).At 3 days postoperation,significant better pain relief was observed in the minimally invasive surgery group than in the open surgery group (P ＜ 0.01),but at the last follow-up no obvious pain was reported in either group.At the last follow-up,there was no significant difference between the 2 groups in ODI (6.2 ± 1.1 versus 6.0 ± 1.4) (P =0.320).Conclusions In the treatment of neurologically intact thoracolumbar fractures,minimally invasive percutaneous pedicle screw fixation may lead to shorter operating time,less blood loss and shorter hospital stay but no poorer radiological outcomes or long-term patient-reported outcomes than the open pedicle screw fixation.However,it should be noted that the former may lead to a higher volume of hidden blood loss.

Objective To discuss the feasibility,the advantages and disadvantages,the clinical efficacy and the indications of minimally invasive transforaminal endoscopic debridement combined with allograft and posterial percutaneous internal fixation for thoracolumbar spinal tuberculosis.Methods All of 22 patients with thoracolumbar tuberculosis treated in our department from January 2012 to December 2013 were retrospectively reviewed.There are 11 male and female cases separately,with an average age of 54.1 ±10.2 years and with an average disease duration of 5.3 ± 1.9 months.Endoscopic lesion removal and allograft bone grafting combined with posterial percutaneous immobilization were performed on all these cases.The data of these patients were complete,and all patients had been followed up for more than 36 months.The clinical and radiographic results were recorded and analyzed.Results In this group,22 patients were followed-up for 41.9±2.5 months(36-48 months).The spinal kyphosis was not improved 3 months after surgery (t=0.3546,P=0.7029),but the amount of blood loss (30.5±7.9 ml) was less in the operation,the amount of postoperative analgesics(0.3±0.1 g) was low and the bed time(1.5±0.3 days) was short.No recurrence and no internal fixation failure was found after long term follow-up.Good clinical outcomes were achieved with the fusion rate reached above grade 2 in all patients(95.5％) except one.The neuralgia was relieved,and the spinal cord injury was recovered to ASIA E.The VAS score and SF-36 score which were recorded 1 month and 3 months after operative were all improved significantly compared with those before operation,and patients' life quality in the early period after operation was excellent.The incidence of complications was low(9.0％),and the patients were satisfied with the treatment process.Conclusion It may be a potential way to treat spinal tuberculosis with minimally invasive transforaminal endoscopic debridement combined with allograft and percutaneous internal fixation,which could be a powerful supplement to other therapeutic measures,and is worthy of further research and development.