Lumbar intervertebrae disc protrusion is a term for the description of morphology, with different pathological changes, pathogenesis and clinical characteristics. We propose a new pathologoical classification including damage-hernia?tion, degeneration-protrusion, posterior vertebral osteochondrosis with disc protrusion, and disc cyst. The appropriate treat?ment including surgical option should be selected according to pathological changes.

BACKGROUND:Femoral head necrosis induced by glucocorticoid is typical under mechanics load.OBJECTIVE:To create the rat models of the femoral head necrosis by long-term glucocorticoid treatment,and to Observe the changes of femoral head necrosis induced by glucocorticoid under mechanics load.METHODS:Wistar rats with 4-month old were randomly divided into the experimental and control groups.After the buttocks injection of dexamethasone 20mg/kg weakly for 8 weeks,rats in the experimental group were made to run on the running machine at a speed of 1 km/h to forme the hyper-weight model;at the same time those in the control group were with the normal physiological weight.Rats in both groups were sacrificed at weeks 2,4,6 and 8.The left legs were taken for the biomechanics test on the EnduraTEC ELF3200,the biggest vertical deformation and stiftness were calculated,the number of empty osteocyte lacunas was calculated,and the cumulative absorbance value was compared between two groups.RESULTS AND CONCLUSION:The femoral head presented with necrosis at 8 weeks in the experimental group.and the width of bone trabecula,and the stiffness of which were smaller than that of the control group.but the biggest vertical deformation was greater the concurrent control group(P＜0.05).The Bcl-2 cumulative absorbance value of 2 groups had significant differences at 4 weeks(P＜0.05),which was increased with time prolonged in the experimental group(P＜0.05).The results demonstrated that:in glucocorticoid-induced osteonecrosis of the femoral head,mechanics Ioad induces the obviously osteocyte necrosis.more cartilage repair,and trabeculae rupture,which is considered as the direct reason of the necrosis of the femoral head The typical femoral head necrosis is presented.

BACKGROUND:It is crucial to determine the location of the rotation center of the hip joint using X-ray.Ranawat's triangle is commonly used to define the hip rotational center in bilateral developmental dysplasia of the hip and revision hip surgery especialy in cases with bone stock deficiency,but there are rare articles about its value in normal hip.OBJECTIVE:To compare the difference between Ranawat's triangle method and Mose circle method in determining the healthy hip joint rotational center.METHODS: We selected 30 patients with normal traumatic femoral neck fracture,who underwent unilateral total hip arthroplasty.Ranawat's triangle method and Mose circle method were applied to measure the anteroposterior radiographs of the pelvis after arthroplasty and to compare the distance between the hip rotational center and the reference lines (X-axis: teardrop line; Y-axis: a line perpendicular to the X-axis,drawn from the intersection of theKohler line and the teardrop line.The distance from the hip joint rotational center to X-axis is dx1,dx2 and the distance to Y-axis is dy1,dy2 in Ranawat's triangle and Mose circle respectively.).We also compared the ratios (dx1/H,dy1/W; dx2/H,dy2/W) in the pelvic height (H: the distance between the highest point on the iliac wing and the lowest point on the ischial tuberosity) and width (W: the distance between the most lateral points on the iliac crests).RESULTS AND CONCLUSION:When the values were compared with both methods,highly significant differences were observed for both X and Y,Ranawat's triangle method dx1=(19.52±3.03) mm,dy1=(24.43±2.26) mm; and Mose circle method dx2=(11.90±3.55) mm,dy2=(34.29±3.79) mm (P＜0.001) and these ratios (dx1/H=0.0992±0.0133,dy1/W=0.0855±0.0069; dx2/H=0.0611±0.0194,dy2/W=0.1201±0.0178) in pelvic height and width (P＜ 0.001).Scatterplot results demonstrated that the hip rotational center identified by Ranawat's triangle method is near to the proximal end and medial end,which may affect mechanical environment surrounding the joint.For cases of bilateral hip dysplasia and joint revision,because of the changes in structure surrounding the acetabulum,Ranawat's triangle method can be a feasible method to identify the hip rotational center.For cases of unilateral lesion,Mose circle method can exactly identify the hip rotational center taking healthy side as a control.

Peripheral nerve injury is very common in clinics. It has brought the patients with high rate of disability and huge economic burden and become one of serious health problems in the world. Nowadays, with the development of nerve tissue engineering, it provides new method for surgical procedures of nerve defects repair.The nerve scaffold plays a vital role in repairing nerve defects. It can provide temporary support for nerve cells to grow,adhere and to form structures. This review aims at introducing classification, properties and the applications of the nerve scaffolds for tissue engineering. Future development of the nerve scaffolds and remaining problems are discussed as well.

BACKGROUND:The main change of knee osteoarthritis is cartilaginous degeneration and secondary bone hyperplasia. The mechanism of these pathological changes is unclear, but some experiments have proved that the onset of knees osteoarthritis is closely related to inflammatory substances.
OBJECTIVE:To discuss the role of inflammatory substances in the pathogenesis of knee osteoarthritis.
METHODS:According to diagnostic criteria set by the American Colege of Rheumatology, we selected 60 knee osteoarthritis patients as experimental group, and another 60 patients undergoing the operative treatment of traumatic amputation or meniscus injury (except knee injury) as control group. After extracting synovial fluid samples from two groups, ELISA assay method was used to detect the levels of interleukin-1β, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor α, basic fibroblast growth factor, and osteopontin. The nitric oxide level in the synovial fluid was detected with nitric oxide detection kit. The content of lipid peroxidase was detected using TBA fluorescence method.
RESULTS AND CONCLUSION:We found higher levels of interleukin-1β, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor α, basic fibroblast growth factor, osteopontin, nitric oxide, and lipid peroxidase in knee osteoarthritis patients, and these levels were positively correlated with knee osteoarthritis. These inflammatory substances are realy involved in the inflammation process of knees osteoarthritis.

BACKGROUND:Discitis is an inflammatory lesion of the intervertebral disc.However,it attracts more attention on autoimmune factors.OBJECTIVE:To construct discitis animal model by destroying the fibrous ring and the cartilage lamina through the surgery,in addition,to explore the changes of autoimmune reaction.DESIGN,TIME AND SETTING:Randomized controlled animal experiment was performed at the Orthpeadic Laboratory of General Hospital of Tianjin Medical University from June to December 2007.MATERIALS:Fifty healthy,adult,New Zealand rabbits,irrespective of gender,were randomly divided into the model(n=30),sham operation(n=10)and control(n=10)groups.METHODS:Thirty rabbits were randomly selected after anesthetized,L3-4,L4-5,L5-6 intervertebral discs were exposed,discitis models were created by destroying the fibrous ring and the cartilage lamina with self-made transfixion pin.Animals in the sham operation group were exposed intervertebral discs without damage.Rabbits in the model and sham operation were executed to get the intervertebral disc specimens at weeks 1,2,4,8,and 12 after operation.MAIN OUTCOME MEASURES:①Hematoxylin-eosin staining,immunocytochemical comparison and lymphocytic expression.②The positive CD4 cells,CD8 positive T cells,as well as the expression of IgG,IgM were detected by immunohistochemistry and immunofluorescence technique.③Bacteriological cultivation.RESULTS:Under light microscope,the internal and external layer fibrous rings could be seen disordered,with inflammatory reaction and fibrosis in the model group.However,there was no same appearance in the sham operation and control group.Immunohistochemistry showed that there was more CD4 positive lymphocyte expressed at weeks 1 and 2 after operation,and the CD8 positive lymphocyte expressed more at 2 and 4 after operation.There was a few lymphocyte expressions in the sham operation group,and no expressed in the control group.Immunofluorescence demonstrated that immune globulin IgG,IgM was positive,a little expression was found in the model group at 1 week,which increased at the 2,4,and 8 weeks after operation.Only a little of IgG expression could be found in the sham operation and control groups.The bacteriological cultivation was negative.CONCLUSION:①Discitis animal model can be established by using the anterior external surgery to destroy the fibrous ring and the cartilage lamina.②After destroying the fibrous ring and the cartilage lamina,the contact between the autoantigen of the nucleus pulposus and blood circulation will provocate autoimmune reaction,which display in both cellular immunity and humoral immunity.③Autoimmune reaction plays a vital role in pathogenesy,pathological change and symptom generating of discitis.

Low back pain has a serious impact on people's lives in t he world.With the approaching of aging society in China,the number of low back pain increased rapidly.Though many of the pathological factors in spine might lead to low back pain,Modic changes (MCs) was one of the most important factors.Therefore,to get familiar with MCs in the etiology and pathology has a positive practical significance.Although a large number of studies have analyzed the epidemiological and imaging characteristics of MCs,there are relatively few studies on the histological and pathological fields of MCs.In recent years,researchers have gradually shed some light on etiology of MCs and found that low toxic bacterial infection and autoimmune reaction may play a vital role in the development of MCs.The damage of vertebral body or endplate is closely related to the etiopathogenesis of MCs.In addition,to reveal the pathological characteristic of MCs is also a good attempt for better understanding of MCs.There are various imaging changes in MCs,however,what is the pathological basis behind it.It is also unclear that why different types of MCs are capable of transformation? When MCs occur,the activation of some cytokines (such as IL-6,RANKL,etc.) and certain receptors (TLR,PPARγ,etc.) can interfere with the formation and metabolism of the nearby bone marrow cells,break the balance of formation and absorption in trabecular beam and further change their microstructures through various pathways.During this dynamic balance process,the different types of MCs can be transformed into each other.The specific type may not only depend on the intensity and duration of inflammatory stimulus,but also rely on the composition and metabolic status of the bone marrow.Although the study of animal models has made some progress,some limitations still exist in practical course.Due to the unclear mechanism of MCs,the study on etiology and pathology of MCs may play a great important role in clarifying this issue.

ObjectiveTo investigate the changes of serum growth hormone (GH)/insulin-like growth factor- Ⅰ ( IGF- Ⅰ ) in patients with traumatic long bone fractures and the related clinical significance.MethodsTwenty-one patients with traumatic long bone fractures from the same trauma care center treated between November 2009 and April 2010 were enrolled in the study..There were 14 males and 7 females,at age range of 22-60 years (mean 45.0 years).Seventeen patients (81％) were with closed trauma and four ( 19％ ) with open trauma.Enzyme Linked Immunoadsorbent Assay (ELISA) was used to determine the levels of serum GH and IGF- Ⅰ within 14 days after fractures and the relationship between changes of GH-IGF- Ⅰ axis and injury severity score (ISS) was further analyzed.Eight patients with normal GH/IGF- Ⅰ were set as control group.ResultsThe GH level in the peripheral blood was significantly higher at day 1 after fractures ( P ＜ 0.05 ),and rapidly declined and stabilized at day 5 compared with the control group.The GH level in the patients with ISS≥ 18 points was sigmficantly higher than that in those with ISS＜18 points at day 1 after fractures (P＜0.05).The IGF- Ⅰ level in the peripheral blood in the patients with 1SS≥ 18 points was significantly higher than that in those with ISS ＜ 18 points at days 5-10 after fractures ( P ＜ 0.05 ).ConclusionThe hypothalamus GH-IGF- Ⅰ axis plays an important role in early metabolism and fracture healing during the acute phase of traumatic long bone fractures.

Estrogen is involved in the process of postmenopausal osteoporosis, and the main functional cells are osteoclasts. However, the mechanism of estrogen on the osteoclasts is not yet fully understood. Here we demonstrate the effects of estrogen on osteoclasts in three aspects: morphology and structure, apoptosis of osteoclasts and differentiation of preosteoclasts, which give an overall explanation for effects of estrogen on osteoclasts.

0.05). The mean degrees for coronal inclinations of facet joint of the patients with degenerative spondylolisthesis were significantly greater than those of the patients without degenerative spondylolisthesis (P