Biomedical subjects

Yueming Song

Publications and source records attributed to Yueming Song.

11 recordsLinked to original sources

PubMed2006

[The finite element analysis of lumbar fusions].

OBJECTIVE: To investigate the stability and the stress distributions of L(3-5) fused with three different approaches (interbody, posterolateral and circumferential fusions) and to investigate degeneration of the segment adjacent to the fused functional spinal unit. METHODS: A detailed L(3-5) three-dimensional nonlinear finite element model of a normal man aged 32 was established and validated. Based on the model, the destabilized model, the interbody, posterolateral and circumferential fusions models of L45 were established. After the loadings were placed on all the models, we recorded the angular motions of the fused segment and the Von Mises stress of the adjacent intervertebral disc. RESULTS: The circumferential fusion was most stable than the others, and the interbody fusion was more stable than the posterolateral fusion. The maximal Von Mises stress of the adjacent L3.4 intervertebral finite all the models was ranked descendingly as flexion, lateral bending, torsion and extension. For the three kinds of fusions, the stress increment of the L34 intervertebral disc was ranked ascendingly as interbody fusion, posterolateral fusion and circumferential fusion. CONCLUSION: After destabilization of the L(4.5) segment, the stability of the circumferential fusion is better than that of the others, particularly under the fluxional or extensional loading. The stability of the interbody fusion is better than that of the posterolateral fusion, except for under the fluxional loading. The feasibility of adjacent segment degeneration can be ranked descendingly as: circumferential fusion, posterolateral fusion and interbody fusion.

Adult↗

PubMed2006

[Fusion of reconstructed titanic plate, vertebral pedical screws and autogenous granulated cancellous bone graft in posterior occipitocervical region].

OBJECTIVE: To explore the technique of fusing the reconstructed titanic plate, the C2 pedical screws, and the autogenous granulated cancellous bone graft in the occipitocervical region. METHODS: From April 2002 to January 2005, 19 patients aged 31-67 years with occipitocervical instability underwent the occipitocervical fusion using the reconstructed plate, C2 pedical screws, and autogenous granulated cancellous bone graft. Of the patients, 8 had complex occipitocervical deformity, 8 had old atlantoaxial fracture and dislocation, 2 had rheumatoid arthritis and anterior dislocation of the atlantoaxial joint, and 1 had cancer of the deltoid process of the axis. RESULTS: No complication occurred during and after operation. The follow-up for an average of 16 months in 19 patients showed that all the patients achieved solid bony fusion in the occipitocervical region. There was no broken plate, broken screw, looseness of the internal fixation or neurovascular injury. CONCLUSION: The fixation of the C2 pedical screws with the reconstructed titanic plate is reliable, the insertion is easy, and the autogenous granulated cancellous bone graft has a high fusion rate, thus resulting in a satisfactory effect in the occipitocervical fusion.

Adult↗

PubMed2006

[The reconstruction of three dimensional nonlinear finite element model of L3-L5 motion segment].

In this study, a detailed L3-L5, three dimensional nonlinear finite element model of a normal aged 32 man was established with the aid of two softwares, CATIAV5 and MSC. Marc, which can derive a three-dimensional finite element model from CT images. We loaded the model with 10 N * m net moment and computed the average rigidity of functional spinal unit. The model was validated in contrast to the former biomechanical studies of cadaveric spine. The model will be used in further clinical biomechanical studies.

Adult↗

PubMed2005

[Study on the effect of composite of basic fibroblast growth factor and partially deproteinized bone on the repair of femoral head defects].

OBJECTIVE: To evaluate the effect of composite (bFGF/PDPB) of basic fibroblast growth factor (bFGF) and partially deproteinized bone (PDPB) on the repair of femoral head defect. METHODS: Forty-eight femoral heads with defect derived from 24 New Zealand rabbits were divided into 3 groups at random, which were implanted with bFGF/PDPB (group A), PDPB (group B) and nothing (group C) respectively. The rabbits were sacrificed at 2, 4, and 8 weeks after operation, and then the femoral heads were obtained. The specimens injected with Chinese ink were created. Then X-ray examination, histopathological and morphological examination of blood vessel, and image analysis were made. RESULTS: The bone defects healed completely 8 weeks after operation in group A. The implants in the repaired tissue were not substituted completely in group B. The bone defects did not heal completely in group C. Two weeks after operation, affluent newly formed vessels were seen in repaired areas in group A. No significant difference between group A and group B was observed 8 weeks after operation. In group C, newly formed vessels were scarce 2, 4, and 8 weeks after operation. There were 3 sides rated excellent, 2 good and 1 fair in group A; 1 excellent, 2 good, 2 fair and 1 poor in group B; and 1 fair and 5 poor in group C according to the X-ray evaluation 8 weeks after operation. Eight weeks after operation, the volume fraction of bone trabecula in repaired tissue was higher in group A than that in group B (P < 0.05), and the fraction in group C was the lowest among the 3 groups (P < 0.05). CONCLUSION: The composite of bFGF and PDPB can effectively promote the repair of femoral head defect of rabbit.

Animals↗

PubMed2005

[Experimental study on the polylactic acid glue in preventing epidural adhesion].

OBJECTIVE: To determine the ability of the polylactic acid glue (PLA-G) in preventing epidural adhesion after laminectomy. METHODS: Each of the 24 randomly selected rats was done laminectomy of L2 and L5. The PLA-G, which would change from liquid to solid when meets with serum, was used in the epidural site of L5 to become a half-solid membrane (the experimental group, EG). The PLA-G was not used in the same site of L2 (the control group, CG). The gross anatomical, histological, and microscopical evaluation were made 2, 4, 6, 8, 10 and 12 weeks after operation; electron microscope observation was also made on two rats 4 weeks after operation(both EG and CG). RESULTS: Obvious epidural space was observed between dura mater and scar tissue (ST), but no cells in the epidural space were observed in EG 2 weeks after operation. Corps of the red cells between dura mater and ST and proliferation of fibroblast cell (FB) were observed in CG 2 weeks after operation. Some remaining glue shivered in the epidural space with lightly increasing fibroblast and smooth dura mater were observed in EG 4 weeks after operation. However, fragile scar adhered with dura mater diffusely and more FB were observed in CG. From the 6th week to the 12th week, a potential interspace between scar and dura mater was observed and PLA glue was absorbed completely in EG. However, tougher scar, which was very difficult to dissect from dura mater and surrounding tissues, was observed. According to the fibroblast ultrastructure observation, bigger nucleus and more plentiful rough endoplasmic reticulum were observed in CG. CONCLUSION: The PLA-G can effectively reduce the epidural scar and adhesion in animal experiment.

Adhesives↗

PubMed2005

[Culture of chondrocytes onto poly-DL-lactide scaffoldings: experimental study].

This experimental study was intended to find the possibility of using PDLLA as scaffolds in tissue engineering and to assess the effect of PDLLA scaffolds with different porosity on chondrocytes. Chondrocytes were cultured when they were seeded onto PDLLA scaffolds with different porosity. Under scanning electron microscope, the scaffolds in hydrophila and adsorptivity to chondrocytes and the function of the cells were observed. The chondrocytes were noted to proliferate on PDLLA scaffolds with different porosity, those with 90%-96% porosity being significantly better. So PDLLA can be used as a scaffold in tissue engineering, and the proper porosity of PDLLA scaffolds should be 90% approximately 96%.

Cells, Cultured↗

PubMed2005

[A preliminary clinical study on absorbable screws].

To evaluate the application of self-reinforced ploy-DL-lactide (SR-PDLLA) absorbable screws in the treatment of spongy bone and intra-articular fractures, the internal fixation with SR-PDLLA absorbable screw was performed on 58 cases,of which 25 were medial malleolus fractures, 14 condyle of humerus fractures, 9 tibial plateau fractures, 7 ulnar olecranon fractures, and 3 lateral malleolus fractures. Observations were made on the orthopaedic operation sites and overall conditions frequently and radiography was performed for periodic analysis. The results showed that SR-PDLLA absorbable screws were particularly effective and reliable, they had good biocompatibility in the treatment of spongy bone and intra-articular fractures and could be used safely in clinical practice.

Absorbable Implants↗

PubMed2004

[Pathological development of researches on intervertebral disc degeneration].

This article reviews the literature about the etiology and pathology of intervertebral disc degeneration. The degeneration of intervertebral disc is associated with certain biomechanical factor. Stress can directly lead to the rupture of intervertebral disc and, more importantly, change its biological properties. And then, it can trigger the process of degeneration via inflammatory mechanism which may include autoimmunity.

Biomechanical Phenomena↗

PubMed2003

[Effect of absorbable poly-DL-lactide rods on experimental fracture healing].

This study was designed to assess the effect of a home-bred poly-DL-lactide (PDLLA) rods on experimental fracture healing. An operation was performed to create bilateral ulnar and radial fractures of forearm in 15 rabbits. The right sides were fixed with 2 PDLLA (Mv = 34 x 10(4), 1.6 mm x 1.6 mm x 30 mm) rods, and the contralateral sides were fixed with 2 Kirschner wires to be used as controls. After operation, casts were used for external fixation, and the joint above and the joint below the fracture were immobilized. The casts were removed at the 6th week after operation. The specimens were removed at specific intervals between 2 and 12 weeks. Histologically, the light microscopy and scanning electron microscopy evaluation of the rabbit ulnar and radial fractures fixation revealed that, the fractured bone gradually healed and the PDLLA rods properly fixed on the fracture area during the implanted period. However, results suggest that internal fixation by absorbable material made the course of fracture healing slower than that in the control group, but the osteogenesis appeared to be normal. In the absorbable group, the collagenous fiber was characterized by order and orientation, and calcified normally. In conclusion, this kind of PDLLA rods have an effect on delaying the process of the normal union of fracture and should be applicable to fractures where the tissues are rich in blood supply.

Absorbable Implants↗

PubMed2002

CT value analysis and clinical significance before and after percutaneous lumbar discectomy.

OBJECTIVE: To provide theoretical basis for effect and mechanism of percutaneous lumbar discectomy in clinic. METHODS: A total of 180 patients with lumbar intervertebral disc herniation were evaluated by CT on the fifth day before and after operation. Meanwhile, CT value was measured in the determined level and region. RESULTS: After operation, CT value of the central and posterior determined point of herniated intervertebral disc was lower significantly than that before operation (P<0.01), but CT value of the anterior determined point was different insignificantly. The excellent and good results of the patients together were 83% postoperatively. CONCLUSIONS: The curative effect of percutaneous lumbar discectomy is achieved through reduction of lumbar intradiscal pressure.

Adult↗

PubMed2002

The influence of the intervertebral disc on stress distribution of the thoracolumbar vertebrae under destructive load.

OBJECTIVE: To compare the influence of normal and degenerative discs on stress distribution of the thoracolumbar vertebrae under destructive load, explore the biomechanical background and clinical meaning and provide theoretical basis for clinical diagnosis and treatment. METHODS: A mechanical model of thoracolumbar motion segment of normal and degenerative discs was built with a three dimensional finite element method and three stresses of vertical compression, compressive flexion and distractive flexion were comparatively analyzed. RESULTS: With vertical compression and compressive flexion loads, the thoracolumbar motion segment of the normal disc showed that the central part of the upper and lower end-plates of the vertebrae and the central part of the trabecular bone adjacent to the end-plate were loaded with the most intensive stresses, meanwhile, the postero-lateral part of the annulus fibrosus was concentrated with stresses. Degenerative disc showed that the stress distribution of the trabecular bone was relatively averaged, the stresses of the central part adjacent to the end-plate were low, while at the same time, the stresses of the peripheral part were elevated relatively. With distraction flexion load, the stresses of the cortex bone, trabecular bone, end-plate and annulus fibrosus of the thoracolumbar vertebrae of degenerative discs were low, meanwhile, the stresses of the posterior structure of the vertebral body were relatively elevated compared with that of normal discs. CONCLUSIONS: There is difference in influence between normal and degenerative discs on the stress distribution of the thoracolumbar vertebrae with destructive load. The transferring way of load is changed after disc degeneration.

Elasticity↗