Objective To study the methods for reconstruction of pelvic ring after subtotal sacrectomy of primary sacral bone tumor.Methods The pelvic ring of nine patients with primary sacral bone tumor were reconstructed by internal fixation after sacrectomy.Results In 9 patients,all were followed-up and got satisfactory functional recovery, the pelvic ring was stable without dislocation.Conclusions Operation should be considered and adopted for primary sacral bone tumor. Reconstruction of sacrum with internal fixation can improve the stability of the pelvis.

Objective To study the methods for treatment of distal femoral complicated fractures.Methods Twenty-seven cases were treated using condyle sustain plate after open reduction.Results In 27 patients,all were followed-up for average 1 5 years,complications included two cases of phocomelia and another two patients with valgus deformity.According to Merchan standards,the rate of the excellent and the good was 73 9%.Conclusion Sustain plate is an excellent alternative for the treatment of distal femoral supracondylar fracture and intercondylar comminuted fracture.

[Objective]Design the Static Three Dimensional Screw-Plate system(STDSP), bring a new instrument for the treatment of femoral neck fractures, which has good biome chanical features of axial loading and rotation stability and can reestablish the loss of support of the posterior neck of fracture with posterior comminution. [Method]Design the STDSP. To the fracture group,one femur of each pair was randomly selected to be stabilized by STDSP, and the other was fixed by the three cancellous lag screws(TCS). Then the constructions were tested with axial loading or rotation to failure. The intact group were fixed and then taken out with the two methods, then tested with axial loading. [Result] (1)Rotation test: Compare the loads of the same rotation angle and the loads of the same width the anterior gap of the osteotomy open, STDS group is bigger than TCS group(PTCS group (P

[Objective]To explore the curative effect of lumbar discogenic low back pain treated with posterior lumbar interbody fusion(PLIF)and transpadicular instrumentation.[Method]Thirty-six patients with lumbar discogenic low back pain were treated with disc excision,lumbar interbody fusion and transpedicular instrumentation.The clinical results were evaluated by pre-and post-operative VAS(visual analogue scale),and the fusion rates were evaluated by X-ray of the lumbosacral spine.[Result]The average period of follow-up was 16 months,ranging from 8 to 28 months.Low back pain basically disappeared in 33 patients treated with PLIF,mild back pain occurred in 3 patients;the VAS after operation decreased significantly in comparison with that of preoparation(P

0.05).There were significant differences between group B and C pre and postoperatively(P

BACKGROUND: The commonly used research methods of lumbar biomechanics are animal model,physical model and corpse model respectively. However, each model has its own disadvantages.OBJECTIVE: To establish the finite element model of lumbarmotionsegments in order to provide theoretical basis for biomechanical research of lumbar.DESIGN: Single sample study based on healthy volunteer.SETTING: Orthopaedic department of a university hospital.PARTICIPANTS: The experiment was completed in the Orthopaedic Department of Xiangya Hospital of Central South University from December 2003to August 2004. A healthy male volunteer was chosen as a mock object.METHODS:CT scanning was conducted to the spine(T12 - S1) of a healthy volunteer by 2 mm layer and got 264 images. The 3D model of normal Chinese male L4 5 motion segments was built by combininglumbar images scanned by CT and anatomic data through 3DSMAX software. Then it was transferred into finite elementmodel by finite element analyzing software SAP2000.MAIN OUTCOME MEASURES: ① Vertebral body model andintervertebraldisc model built by 3DSMAX software; ② Finite element model of motion segment made by SAP2000 software.RESULTS:The finite element model of lumbar L4-5 segments had been built. It had totally 2 120 nodes that include 1 728 Solid units, 592 Area units and 50 Link units.CONCLUSION: The finite element model of lumbar motion segments can be established through CT scanning, digital image processing and computer aid design to further study the biomechanics of spine.

BACKGROUND: Artificial lumbar disc replacement is a novel approach to treat lumbar disc protrusion. But its theoreticalbasis needs further verification.OBJECTIVE:To establish finite element model of lumbar disc replacement for biomechanical studies.DESIGN: A single sample study taking the data of L4-5 three-dimensional infinite element model as object of research.SETTING: Orthopedic Department of Xiangya Hospital of SunYat-sen University.PARTICIPANTS: The trial was conducted in the Laboratory of the Orthopedic Department of Xiangya Hospital from December 2003 through August 2004. A healthy male volunteer served as simulation. His T12-S1 underwent continuous CT scanning. There were altogether 264 images with 2 mm inthickness each. Three-dimensional images were reconstructed every 15° in order to obtain the data for three-dimensional model.METHODS: The CT images and human anatomical data were processed by 3DSMAX software to establish three-dimensional L4-5 model of normal Chinese males. It was then transformed to finite element model after processed by SAP2000 software together with Charite SB Ⅲ disc prosthesis model.MAIN OUTCOME MEASURES: The three-dimensional model and finiteelement model of lumbar spine were successfully established.RESULTS: The finite element model of Charite SB Ⅲ disc replacement in L4_5 spine was established. The total nodes were 2542 and there were 1924Solid units, 592 Area units and 50 link units.CONCLUSION:The finite element model of artificial disc replacement can be established by CT scanning, digital processor and computer aideddesign,and used for further study on spinal biomechanics.

Objective To evaluate the value of Vascular Closure Device(VCD)with the new Angio-Seal STS(Self-Tightening Suture)in femoral artery closure after coronary angiography(CAG)or percutaneous coronary intervention(PCI).Methods Totally 298 patients were divided into Angio-Seal STS group(group A,n=120)and manual compression group(group B,n=178).The success rate of hemostasis,the time of hemostasis,the time of bedrest and the complication rate were observed.Results Compared with group B,the time of hemostasis,the time of bedrest and the rate of distress on the waist were markedly decreased in group A(P0.05).Conclusion Angio-Seal STS vascular closure derice provided a safe and effective means of obtainig rapid arterial hemostasis after cardiac catheterization.It reduces the bedrest time and discomfort without increasing complications.Angio-seal STS device has the feature of self tightening suture,and doesn't need the post-placement tension spring.

Objective To investigate the properties of cultured periosteal cells associated with bone morphogenetic protein(BMP) to find a new treatment for bone defects.Methods The periosteal cells were cultured,expanded and passage cultured in vitro to investigate the characteristics and functional changes of rabbit periosteal cells.Animal models of 1.0cm gaps with complete removal of the bilateral radius medium bone and periosteum were induced in 24 New Zealand rabbits,which were randomly divided into 4 groups to receive the defect repair with periosteal cells combined with BMP,periosteal cells,BMP and blank control respectively.X-ray and histological examination were made periodically after operation to evaluate the effectiveness of bone formation.Results Periosteal cell morphology can be divided into three stages: cell division phase,cell growth phase and cell functional phase.Cellular configuration had no significant difference with primary cells after anagenesis.The callus can be formed after the periosteal cells were transplanted into the bone defection.The osteogenesis ability of periosteal cells combined with BMP was better than that of the BMP,and the osteogenesis ability of the BMP was better than that of the periosteal cells.The mechanism of bone regeneration for periosteal cells was similar to intramembranous ossification,and that of BMP was similar to endochondral ossification.In the periosteal cells combined with BMP group,both intramembranous and endochondral ossification existed,and the former was obvious.Conclusion Both periosteal cells and BMP can improve the repair of bone defect in vivo.Cultured periosteal cells combined with BMP had substantial ability of synergistic osteogenesis,and it was an ideal treatment for bone defection.

Objective To investigate the expression and significance of vascular endothelial growth factor(VEGF) in the various types of degenerated lumbar discs and the normal control.Methods Forty-one cases of degenerated intervertebral disc tissue(the contained group with 17 cases and uncontained group with 24 cases) from surgical intervention for lumbar disc herniation and 13 cases of normal disc tissue from anterior approach for scoliosis and lumbar fracture were stained with hematoxylin and eosin.The expression of VEGF was tested by immunohistochemistry method.Results There was no capillary infiltration and VEGF positive expression in the control group.The VEGF positive rate was 41.2%(7/17) in the contained group,and 79.2%(19/24) in the uncontained group.In the contained group and uncontained group,the VEGF positive rate was higher than that in the control group(P