BACKGROUND:There is no doubt that animal model of fracture is the basis of fracture healing research.The fracture animal mode is divided into open osteotomy model and closed fracture model.There is no research about the difference between two kinds of fracture rat models.OBJECTIVE:To compare the modeling process between open osteotomy model and closed fracture model in rats,and to compare fracture healing using radiograph.DESIGN,TIME AND SETTING:The randomized,controlled animal experiment was performed at the Laboratory of Department of Orthopaedics,Second Affiliated Hospital,Soochow University from January to May 2007.MATERIALS:A total of 40 SPF male Sprague Dawley rats,weighing(220?30) g,were randomly divided into an open osteotomy model group and a closed fracture model group,with 20 rats for each group.Electric swing saw was a kind of self-made percussion device for closed fracture models.METHODS:All rats in the open osteotomy model group received open osteotomy to create transverse fracture of the middle femur,and fixed using Kirschner wire.Rats in the closed fracture model group received retrograde Kirschner wire fixation,and midshaft femoral closed fracture induced by model establishment stent.MAIN OUTCOME MEASURES:Mean model establishment time;Successful rate of model establishment;Radiography of fracture healing at 2,3,4 and 8 weeks after surgery.RESULTS:Success rate of open osteotomy model establishment was 90%.Average modeling time was 17 minutes.Rate of malunion and nonunion was 40%.Successful rate of each closed fracture models was 85%,with average modeling time was 12 minutes.There was no malunion and nonunion.At 2,3 and 4 weeks after surgery,X-ray score was lower in the open osteotomy model group compared with the closed fracture model group(P 0.05).CONCLUSION:Model establishment of open osteotomy takes a longer time,with a high rate of malunion and nonunion.In near future or medium-term,fracture healing is significantly lagged.Thus,open osteotomy is not suitable for the study of early or medium-term fracture healing.

Objective To study the application effect of different internal fixation scheme in older children with proximal hu-merus fractures .Methods The clinical data of 102 cases of elder children with proximal humerus fracture from March 2009 to Feb-ruary 2014 in the hospital were retrospectively analyzed according to different internal fixation methods ,they were divided randomly into A ,B ,C group ,34 cases in group A ,using elastic intramedullary retrograde intramedullary internal operation ;32 cases in group B ,using open reduction and Kirschner wire internal fixation operation ;27 cases in group C ,using open reduction and plate internal fixation operation .Compared and study the operation treatment effect on children in three groups .Results The operation time ,hos-pitalization time ,fracture healing time ,the excellent and good rate of postoperative shoulder joint Neer score ,complication rate of patients among the three groups had no statistical significance (P > 0 .05) .Compared with group B and group C ,the amount of bleeding was significantly decreased and incision length was significantly shortened in group A(P< 0 .05) .Conclusion Elastic intr-amedullary retrograte internal fixation ,kirschner wire interal fixation ,open reduction internal fixation ,all can fix proximal humeral fractures in older children safely and effectively ,and the clinical effect of elastic intramedullary retrograte internal fixation is better than other two fixation .

BACKGROUND:Insulin-like growth factor-1(IGF-1) is an important regulator in osteoblasts proliferation,differentiation and matrix synthesis,which participates in the process of fracture healing and repairing. OBJECTIVE:To investigate the potential bone regeneration effect of human bone marrow mesenchymal stem cells(MSCs) transfected into IGF-1 retroviruses vector on bone defects repairing. DESIGN,TIME AND SETTING:A controlled observation experiment was performed between March 2004 and May 2005 at the Laboratory Animal Center of Soochow University. MATERIALS:MSCs were transfected into IGF-1 retroviruses vector in vitro and combined with demineralized bone matrix(DBM) . METHODS:Fifteen BalB/C nude mice were prepared for 8 mm calvarial defects models and divided into 3 groups by number table method,with 5 animals in each group. DBM transfected with IGF-1 and DBM transfected with vector were implanted into the defect in MSCs cells transduced with IGF-1 and vector groups,respectively. There was no other intervention in the blank control group. The implants were harvested and evaluated by histological examination at 4 weeks after model preparation. MAIN OUTCOME MEASURES:①The mRNA expression of IGF-1 was analyzed by RT-PCR and Western Blot. ②The complexes of cells and DBM were analyzed by scanning electron microscope(SEM) at days 3 and 6 after co-culture. ③Gross observation of the calvarial defects models. ④Osteogenic activity of the implants was evaluated by hematoxylin-eosin staining at weeks 4 after model preparation. RESULTS:①There were mRNA and protein expression of IGF-1 in MSCs cells transduced with IGF-1 vector. ②SEM showed that there were plenty of cells adhered to surface of DBM,and grew into inner part at the 3 days after co-culture with IGF-1,which secreted much collagen fibers at days 6. The count of adherent cells and collagen fiber was smaller in the vector group at each time points. ③No obvious inflammatory reaction could be seen in each group at 4 weeks after model preparation. Compared with vector control,abundant new bone and blood vessel formation occurred in the calvarial defects treated with DBM/IGF-1,and no new bone formation in the blank control groups. ④Results of hematoxylin-eosin staining showed that grafts in the MSCs cells transduced with IGF-1 group was combined closely with calvarial defects,new bone and vessel could be found. There were few bone-like materials formation in vector group,and no defects in control group were repaired. CONCLUSION:The composites of IGF-1 transfected MSCs and DBM has good effect in repairing calvarial defects.

Objective To study the clinical efficacy and safety of Bryan-Morrey approach combined with anatomic locking plate fixation for the treatment of type C fractures of distal humerus.Methods Performed a prospective study from from Mar.2011 to Aug.2014.Thirty-three cases of distal humerus fracture were included in our study,and the mean age was (37.3 ±4.1) years old.The fracture type of distal humerus was 13-C according to Mayo classification.All the fractures treated with a Bryan-Morrey approach and anatomic locking plates.In the follow-up,Mayo scores of elbow,measurement of range of motion,elbow flexion and extension muscle strength were recorded and analysed.Results In this study,there were no serious complications,such as nonunion,rupture of triceps tendon and the infection,except partial sensory function injury of ulnar nerve in 5 cases.At the last time of the follow-up,elbow flexion muscle strength and extension muscle strength did not significantly decreased significantly compared with strength of the normal side.The mean flexion of the injured side was (134.5 ± 10.1) degrees,and the mean extension was (-1 1.5 ± 8.1) degrees.According to Mayo elbow performance score,the average scores of elbow was (86.2 ± 7.8),84％ of the patients got excellent or very excellent function results.Conclusion The Bryan-Morrey approach combined with anatomic locking plate fixation is a good choice for the treatment of distal humerus fractures of AO C type.

Objective To observe whether the full-thickness defects of articular cartilage at the knee joint of rabbits could be repaired by implantation of polyglycolic-acid(PGA) composites adhered with bone marrow stromal cells (BMSCs). Methods Culture-expanded rabbits’BMSCs were seeded onto porous PGA scaffolds. After a 72-hour co-culturing, the cell-adhered PGA was implanted into the articular cartilage defect at the intercondylar fossa of the femur. The rabbits were sacrificed 12 weeks later after the operation and the specimens were examined histologically for morphologic features, and stained immunohistochemically for type Ⅱcollagen. Results The specimens harvested from BMSCs-PGA composite demonstrated a hyaline cartilage formation. No obvious progressive degeneration sign was found in the newly formed tissue. The control groups showed no hyaline-like cartilage formation. Conclusion PGA composites adhered with in vitro culture-expanded autologous BMSCs can facilitate formation of hyaline-like cartilage in rabbits.

Objective To investigate the stability of lumbar single?level dynamicly fixed by socket track pedicle screws after decompression. Methods Socket track pedicle screws are made of titanium?alloy, swing like universal screw within the scope of 18° in the sagittal plane and 8° in the horizontal plane. Motion constraints were due to the hole which the screw goes through. Six pig spines (L1-5) were tested by applying a pure moment of 4.018 Nm in 3 directions of loading. The range of motion (ROM) of the following groups underwent different surgical procedures was measured:(1) intact;(2) dynamic fixation 1 (decompres?sion by total laminectomy and instrumentation with socket track pedicle screws); (3) dynamic fixation 2 (decompression by total laminectomy and bilateral facetectomy while instrumentation with socket track pedicle screws);( 4) instability resulted from decom?pression (decompression by total laminectomy plus bilateral facetectomy without any rod);(5) hybrid fixation (decompression by to?tal laminectomy and bilateral facetectomy while instrumentation with 2 socket track pedicle screws connected with 2 unilateral pedicle screws ). Results Compared with the intact specimens (in flexion, extension, lateral bending and rotation, corresponding angular displacements were 1.84°±0.75°, 1.55°±0.34°, 2.2°±1.07°, 2.06°±0.76° respectively), the ROM of segment L3, 4 of each group were significantly restricted except for axial rotation. In flexion, extension and lateral bending, the ROM was reduced to 0.71°±0.39°, 0.46°±0.18°, 0.85°±0.66° in dynamic fixation 1 group;0.79°±0.43°, 0.71°±0.20°, 1.17°±0.48° in dynamic fixation 2 group and 0.63°±0.50°, 0.37°±0.19°, 0.54°±0.60° in hybrid fixation group. The rotation ROM of dynamic fixation 1 group and hy?brid fixation group were decreased to 1.50°±0.64° and 1.22°±0.36°, whereas the ROM of dynamic fixation 2 had a non?significant reduction to 1.85°±0.67°. The extension and rotation ROM of dynamic fixation 2 increased significantly comparing to dynamic fixa?tion 1 group; the extension, lateral bending and axial rotation ROM of hybrid fixation group were reduced comparing to the state of dynamic fixation 2 group. Conclusion The dynamic instrumentation of single?level lumbar spine with socket track pedicle screws could offer stability in all directions. The flexion, extension, lateral bending and rotation ROM of spine with dynamic instru?mentation after total laminectomy and bilateral facetectomy could be reduced.

Designable experiment refers to such an experiment that students apply their knowledge and experiment skills to design and prepare experimental materials,instruments,means and procedures based on specific purpose and requirements,and finish the formal experiment by themselves.Through designable experiment,students' integration capability such as applying knowledge,manual operation and handling problem are cultured.We explore setting up designable experiment in the course of clinical hematological examination,and evaluate the effectiveness of teaching.

Objective To investigate the effects of quercetin on glial scar formation and axonal regeneration after spinal cord injury (SCI) and its association with the p38 mitogen activated protein kinase (MAPK) signal pathway.Methods 128 female Sprague-Dawley (SD) rats were randomly divided into a control group (SCI + saline),an intervention group (SCI + quercetin + anisomycin),a treatment group (SCI + quercetin) and a sham-operation group (n =32).Basso Beattie Bresnahan (BBB) assessment and footprint analysis of the hind limb were performed on days 1,3,7,14,21 and 28 postoperation in each group.The expression levels of p38MAPK,phosphorylation p38MAPK,glial fibrillary acidic protein (GFAP) and neurofilament protein-200 (NF-200) were detected by Western blot.The numbers of GFAP and NF-200 positive staining cells in the injured spinal cord in each group were detected by immunohistochemistry.Results The BBB scores in the treatment group were significantly higher than in the intervention and control groups at each time point after SCI except on day 3 postoperation (P ＜ 0.05).The expression levels of phosphorylation p38MAPK protein in each SCI group were significantly higher than in the sham-operation group on days 3 and 7 postoperation (P ＜ 0.05).The expression levels of phosphorylation p38MAPK protein in the treatment group were significantly lower than in the control and intervention groups on days 3,7 and 14 postoperation (P ＜ 0.05),but there was no significant difference on day 28 postoperation among all the groups (P ＞ 0.05).The numbers of NF-200 and GFAP positive staining cells were significantly greater than in the sham-operation group at each time point postoperation (P ＜ 0.05);the NF-200 positive staining cells in the treatment group were significantly increased in comparison with the control and intervention groups (P ＜ 0.05);the GFAP positive staining cells in the treatment group were significandy fewer than in the control and intervention groups on days 7,14 and 28 postoperation (P ＜ 0.05).Conclusions Quercetin may have protective effects against acute SCI by decreasing glial scar formation,increasing axonal regeneration and promoting recovery of locomotor and nerve function in rats.The effects may be correlated with inhibition of the p38MAPK signal pathway.

Objective To investigate the effects of bone marrow stromal cell (BMSC) transplantation on axonal and glial scarring after spinal cord injury (SCI).Methods Thirty New Zealand white rabbits were randomly assigned to a sham operation group (group A),a saline treatment group (group B) or a BMSC treatment group (group C).Group A served as controls,in which the canal was opened without damage to the spinal cord.In groups C and B SCI models were established with aneurysm clips and the rabbits of groups C and B were then given injections of BMSCs and saline solution respectively via the intra-intercostal artery at 1 week post injury.At 1 day,1 week,2 weeks and 4 weeks post injury,Basso Beattie-Bresnahan (BBB) scores were assessed to evaluate the recovery of locomotor function in the hind limbs.Spinal cord samples were harvested for HE and Nissl staining,and immunohistochemistry and image analysis were used to detect any changes in neurofilament (NF200) and glial fibrillary acidic protein (GFAP) in the injured spinal cords.Results The average BBB scores of group A were significantly higher those that of groups B and C at each time point,and those of group C were significantly better than those of group B at the 2nd and 4th week post injury.At the 4th week post injury,HE staining showed there was no glial scarring or cavities in group A,but that there was glial cellular proliferation,glial scarring and cavity formation at the injury site in groups B and C.In group C all were obviously less than in group B.Nissl staining indicated there were more typical neurons in group A,while there were a larger number of ruptured neurons,more degradation,and irregular remaining neurons in groups B and C.These abnormalities were again significantly more prevalent in group C.Immunohistochemical examination showed significant increases in NF200 positive neurons and GFAP in groups B and C compared with group A.The number of NF200 positive neurons was significantly higher in group C than in group B,but the GFAP positive area was significantly smaller in group C than in group B.Conclusion BMSC transplantation via the intercostal arteries can effectively improve axonal regeneration,attenuate glial cellular proliferation and reduce glial scar formation,promoting functional recovery after SCI,at least in rabbits.

Objective To discuss the value of the posterior long segments pedicle screws fixation in surgical treatment of thoracolumbar fracture-dislocation,and summarize the experience.Method s We reviewed the clinical information of 27 cases of thoracolumbar fracture-dislocation since July 2007 to March 2010; all the cases were treated with the posterior long segments pedicle screws fixation.In these cases,20were male,7 were female.And the age ranged from 18 to 58 years old (average age was 35 years).The posterior approach was used,and the pedicle screws were inserted into the 2 vertebrae above and below the fractured vertebrae.Posterior decompression and bone grafts for fusion were also accomplished during the operation.Results Follow-up ranged from 7 to 25 months,averaging 14 months.Completely restoration of the dislocation was got in 25 cases and the spine sequence resumed to nearly normal.One case with lateral dislocation failed to complete correction; another 1 case operated 20 days after surgery failed to complete correction of forward dislocation.At the last follow-up,the mean Cobb angle loss was 3 degrees,the height of the vertebral had obvious loss compared with that of post-operation.The loosen of screw nut was found during the follow-up,but no dislocation and secondary deformity were observed after fixation.There was no death,no infection.Conclusions The technique of posterior long segments pedicle screw fixation is of great value in the clinical applications,since it has the following advantages:the operation is simple,trauma is small,the fixation is firm,good restoration of fracture and dislocations can be easily got,and most importantly,it can effectively prevent long-term vertebral height loss and the backward protruding deformity.