Research status of acetabular reconstruction in Crowe type Ⅱ and Ⅲ developmental dysplasia of the hip / 中国骨伤

Developmental dysplasia of the hip (DDH) is a major cause of hip arthritis and ultimately total hip arthroplasty. Due to the dysplastic acetabulum, how to place the acetabular cup becomes a challenge in acetabular reconstruction for such patients. Especially in the acetabula classified as Crowe typeⅡand type Ⅲ, the dislocation of the femoral head causes bone defects above the true acetabulum, which will affect the stability of the acetabular cup when the acetabular reconstruction is performed at the true acetabulum. Many acetabular reconstruction methods such as bone grafting, the use of small acetabular cups, socket medialization technique, and high hip center technique are used to increase the host bone coverage of the cup. However, each method has its own shortcomings that can not be ignored so that there is no unified conclusion on the acetabular reconstruction methods for Crowe typeⅡand type Ⅲ hip dysplasia. This article summarized and evaluated various reconstruction methods in combination with the acetabular morphology of DDH, and put forward the research direction in the future.

Research progression in the pathogenesis of osteoarthritis / 中国骨伤

Osteoarthritis(OA) is one of the most common joint diseases. As Chinese society enters the age of aging, the incidence of OA has been soar year by year, and research on its pathogenesis has been continuously valued by researchers. Studies have found that inflammatory cytokines, mainly interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), were responsible for the construction of OA inflammatory networks. It was also found that the overexpression of proteases, mainly matrix metalloproteinases(MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS), was the direct cause of OA cartilage deficiency. What's more, signaling pathways such as stromal cell derived factor-1 (SDF-1) and Wnt, chondrocytic senescence and the senescence-associated secretory phenotype (SASP), chondrocyte apoptosis and autophagy, and estrogen all play significant roles in OA pathogenesis. This paper extensively reviews the research literature relevant to the pathogenesis of OA in recent years, and systematically expounds the pathogenesis of OA from two aspects:molecular level and cell level. At the end of the paper, we discussed and predicted some potential directions in the future clinical diagnosis and treatment of OA.

Radiological study on the cup abduction angle during total hip arthroplasty / 中国骨伤

OBJECTIVE@#To analyze the relationship among the parameters by measuring the relevant parameters of the anteroposterior X-ray of both hips in patients after total hip arthroplasty, to discuss the reliable anatomical markers and reference standards of acetabulum placement in total hip arthroplasty, and finally to accurately control the abduction angle of acetabulum.@*METHODS@#From January 2016 to June 2017, 282 patients (235 hips) underwent total hip arthroplasty and 128 patients(157 hips) met the inclusion criteria. There were 91 males and 37 females, 82 cases of the left hip and 75 cases of the right hip; ranging in age from 22 to 78 years old, with a mean of 55.1 years old. The abduction angle(β), ilium thickness (a), acetabular cup insertion depth (b), ischial thickness (c), acetabular cup insertion depth(d), acetabular abrasion and contusion depth(e) were measured on the postoperative AP X-ray of both hips, and the data were compared.@*RESULTS@#There was a positive correlation between β and b (=0.424, =0.000), a negative correlation between β and d (=-0.407, =0.000), a positive correlation between β and b/a (=0.419, =0.000), a negative correlation between β and d/c (=-0.472, =0.000). There was a linear relationship between β and b/a (5.753, =0.000) and a linear relationship between β and d/c (-6.671, =0.000).@*CONCLUSIONS@#The outreach angle is mainly controlled by the distance between the outer edge of the cup and the outer edge of the cup in the inferior portion(d) during the operation. The distance b from the outer edge of the cup can be used as a reference.

Measurements and analyses of full length weight bearing X ray radiographs of bilateral lower extremities in patients with knee osteoarthritis / 中国骨伤

<p><b>OBJECTIVE</b>To reveal the characteristics of anatomical and mechanical axes in lower extremities by analyzing full length weight bearing X ray radiographsin patients with knee osteoarthritis(OA).</p><p><b>METHODS</b>From June 2015 to May 2016, the lower extremity CTA was performed for 20 patients with vascular diseases, and these patients without OA were assigned to the normal group. There were 7 males and 13 females, ranging in age from 24 to 72 years old with an average age of 63.2 years old. The weight bearing full length X ray radiographs of the lower extremities were taken for 53 patients with knee OA, and these patients were assigned to the OA group. There were 10 males and 43 females, ranging in age from 52 to 80 years old with an average age of 64.7 years old. The osteoarthritis group were divided into two groups:varus knee group and valgus knee group. The femoral shaft double condyle angle(F), tibial shaft plateau angle(T), joint gap angle(JS), femoral tibial angle(FT), hip knee ankle angle(HKA), knee physiological valgus angle(KPV), and femoral offset were measured. The SPSS 21.0 was used to analyze the statistical data.</p><p><b>RESULTS</b>The mean F were (79.9±2.3)° and (81.4±3.5)°, T were (93.8±3.7)° and (94.6±2.7)°, JS were (1.7±1.0)° and (2.1±2.5)°, FT were (175.4±4.0)° and (178.1±6.3)°, HKA were (181.4±4.1)° and (184.3±6.9)°, KPV were (6.0±1.0)° and (6.2±1.5)°, offset were (38.5±6.5) mm and (38.1±9.2) mm in the normal and OA group respectively. There was a significant difference in the KPV between varus knee and valgus knee groups(=2.956,=0.005), and the greater mean KPV was found in varus knee. Positive correlations were found between KPV and age(=0.241,=0.016), as well as between KPV and offset (r=0.946,=0.000).</p><p><b>CONCLUSIONS</b>The average KPV in patients with knee OA was 6.2° in the present study, and the KPVs were also positively correlated with the patients' ages and the femoral offsets. The average KPV in the varus knee was greater than that of the valgus knee, and the difference was about 1°. The changes of mechanical parameters of lower limb may be one of the risks for developing knee OA. Analyzing the full length weight bearing X ray radiographs of the lower extremities preoperatively will be helpful to determine a individualized osteotomy method for patients.</p>

Case-control study on methods of limb length control in hip arthroplasty / 中国骨伤

<p><b>OBJECTIVE</b>To introduce a new measuring tool for measuring postoperative limb length exactly, and to provide a convenient and effective method to control limb length after total hip replacement.</p><p><b>METHODS</b>From January 2013 to September 2014, 102 patients undergoing primary unilateral hip replacement were divided into two groups: experimental group and control group. There were 51 patients in the experimental group, including 25 males and 26 females, ranging in age from 37 to 92 years old, with an average of 60.41 years old. The patients in experimental group were treated with new method to control limb length. Other 51 patients in the control group, including 27 males and 24 females, ranging in age from 35 to 87 years old, with an average of 61.00 years old. The patients in the control group were treated with normal methods such as shuck test or limb touching. All the patients were operated by the same experienced surgeon. In the experimental group,total hip arthroplasties (THA) were performed on 35 patients with avascular necrosis of the femoral head or femoral neck fracture, and 16 patients were treated with hemiarthroplasty (HA). In the control group, 38 patients received THA and 13 patients received HA. On the anterior-posterior X-ray radiograph, several indexes were measured as follows: the distance of bilateral femoral offset (a), the height from tip of great trochanter to the rotation center of the femoral head (b) and the vertical distance between the top of the minor trochanter and the two tear drops line (c). The leg length discrepancy can be assessed with three parameters as follows: d1, the absolute value of the difference between the bilateral a values; d2, the difference between the bilateral b values; d3, the difference between the bilateral c values. The SPSS 21.0 was applied for the statistical analysis.</p><p><b>RESULTS</b>In the experimental and control groups, d1 were 4.49 mm and 7.32 mm (P = 0.013); d2 were 2.37 mm and 4.32 mm (P = 0.033); d3 were 3.32 mm and 6.08 mm (P = 0.031). The values of d1, d2 and d3 in the experimental group were significant smaller than those in the control group.</p><p><b>CONCLUSION</b>The new measuring tool and method can be used to control the limb length and offset effectively during operation.</p>

Evaluation of the effects of standard rescue procedure on severe trauma treatment in china / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This study aimed to evaluate the effects of standard rescue procedure (SRP) in improving severe trauma treatments in China.</p><p><b>METHODS</b>This study was conducted in 12 hospitals located in geographically and industrially different cities in China. A standard procedure on severe trauma rescue was established as a general rule for staff training and patient treatment. A regional network (system) efficiently integrating prehospital rescue, emergency room treatments, and hospital specialist treatments was built under the rule for information sharing and improving severe trauma treatments. Treatment outcomes were compared between before and 1 year after the implementation of the SRP.</p><p><b>RESULTS</b>The outcomes of a total of 74,615 and 12,051 trauma cases were collected from 12 hospitals before and after the implementation of the SRP. Implementation of the SRP led to efficient cooperation and information sharing of different treatment services. The emergency response time, prehospital transit time, emergency rescue time, consultation call time, and mortality rate of patients were 24.24 ± 4.32 min, 45.69 ± 3.89 min, 6.38 ± 1.05 min, 17.53 ± 0.72 min, and 33.82% ± 3.87% (n = 441), respectively, before the implementation of the standardization and significantly reduced to 10.11 ± 3.21 min, 22.39 ± 4.32 min, 3.26 ± 0.89 min, 3.45 ± 0.45 min, and 20.49% ± 3.11%, separately (n = 495, P < 0.05) after that.</p><p><b>CONCLUSIONS</b>Staff training and SRP can significantly improve the efficiency of severe trauma treatments in China.</p>

Cross-sectional Anatomy of Ilium for Guiding Acetabular Component Placement Using High Hip Center Technique in Asian Population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Many clinical studies have been published involving the use of a high hip center (HHC), achieved good follow-up. However, there is a little anatomic guidance in the literature regarding the amount of bone stock available for initial implant coverage in this area of the ilium. The purpose of this study was to evaluate the thickness and width of the human ilium and related acetabular cup coverage for guiding acetabular component placement in HHC.</p><p><b>METHODS</b>A total of 120 normal hips in 60 cases of adult patients from lower extremities computer tomographic angiography Digital Imaging and Communications in Medicine data were chosen for the study. After importing the data to the mimics software, we chose the cross sections every 5-mm increments from the rotational center of the hip to the cephalic of the ilium according the body sagittal axis, then we measured the thickness and width of the ilium for each cross section in axial plane, calculated the cup coverage at each chosen section.</p><p><b>RESULTS</b>At the acetabular dome, the mean thickness and width of the ilium were 49.71 ± 4.88 mm and 38.92 ± 3.67 mm, respectively, whereas at 1 cm above the dome, decreased to 41.35 ± 5.13 and 31.13 ± 3.37 respectively, and 2 cm above the dome, decreased to 31.25 ± 4.04 and 26.65 ± 3.43, respectively. Acetabular cup averaged coverage for 40-, 50-, and 60-mm hemispheric shells, was 100%, 89%, and 44% at the acetabular dome, 100%, 43.7%, and 27.5% for 1 cm above the dome, and 37.5%, 21.9%, and 14.2% for 2 cm above the dome.</p><p><b>CONCLUSIONS</b>HHC reconstructions within 1 cm above the acetabular dome will be an acceptable and smaller diameter prosthesis would be better.</p>

Zinc finger X-chromosomal protein promotes growth and tumorigenesis in human osteosarcoma cells

To investigate the role of Zinc finger X-chromosomal protein [ZFX] in oncogenesis of Osteosarcoma tumor. Here, we first conducted an expression analysis of ZFX in Osteosarcoma cell lines. Then, we constructed ZFX-specific small interfering RNA [siRNA]-lentiviral vector that is capable of effectively inhibiting the expression of ZFX gene in human Osteosarcoma Saos-2 cells, and investigated systemically the impacts of ZFX silence on the growth and invasive ability of the cancer cells in vitro. Furthermore, we determined the effects of ZFX knockdown on the cell cycle distribution and apoptosis of Saos-2 cells. We found that ZFX inhibition resulted in significantly impaired proliferation and colony formation as well as mitigated invasiveness of Saos-2 cells. Importantly, si-ZFX infected cells exhibited a greater portion of cells at G1 phase, but a minor portion of S and G2/M phase cells. Moreover, a greater portion of sub-G1 apoptotic cells was observed in si-ZFX infected cells. These results strongly suggest that ZFX is a novel proliferation regulator that promotes growth of Osteosarcoma cells, and downregulation of ZFX expression induces growth suppression of Saos-2 cells via arrested G0/G1 phase cell cycle and apoptosis pathways, thereby indicating that ZFX may serve as a new molecular target for Osteosarcoma tumor therapy

Association of sterol regulatory element binding protein 2 and insulin-like growth factor binding protein 3 genetic polymorphisms with avascular necrosis of the femoral head in the Chinese population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Sterol regulatory element binding protein (SREBP)-2 plays a key role in lipid homeostasis by stimulating gene expression of cholesterol biosynthetic pathways. The insulin-like growth factor binding protein (IGFBP) family regulates growth and metabolism, especially bone cell metabolism, and correlates with osteonecrosis. However, association of their gene polymorphisms with risk of avascular necrosis of the femoral head (ANFH) has rarely been reported. We determined whether SREBP-2 and IGFBP-3 gene polymorphisms were associated with increased ANFH risk in the Chinese population.</p><p><b>METHODS</b>Two single nucleotide polymorphisms of SREBP2 gene, rs2267439 and rs2267443, and one of IGFBP-3 gene, rs2453839, were selected and genotyped in 49 ANFH patients and 42 control individuals by direct sequencing assay.</p><p><b>RESULTS</b>The frequencies of rs2267439 TT and rs2267443 GA of SREBP2 and rs2453839 TT and CT of IGFBP-3 in the ANFH group showed increased and decreased tendencies (against normal control group), respectively. Interaction analysis of genes revealed that the frequency of carrying rs2267439 TT and rs2267443 GA genotypes of SREBF-2 in ANFH patients was significantly higher than in the control group (P < 0.05). Association analysis between polymorphisms and clinical phenotype demonstrated that the disease course in ANFH patients with the rs2453839 TT genotype of IGFBP-3 was significantly shorter than that of CT + CC carriers (P < 0.01). CT + CC genotype frequency in patients with stage III/IV bilateral hip lesions was significantly higher than in those with stage III/IV unilateral lesions and stage II/III bilateral lesions (P < 0.05 - 0.02).</p><p><b>CONCLUSIONS</b>Our results suggested that interaction of SREBP-2 gene polymorphisms and the relationship between the polymorphisms and clinical phenotype of IGFBP-3 were closely related to increased ANFH risk in the Chinese population. The most significant finding was that the CT + CC genotype carriers of IGFBP-3 rs2453839 were highly associated with the development of ANFH.</p>

Differential diagnosis of cervical radiculopathy and superior pulmonary sulcus tumor / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The result would be disastrous if the superior pulmonary sulcus tumor (Pancoast tumor) was misdiagnosed as degenerative cervical spine diseases. The aim of this study was to investigate the differential diagnosis methods of cervical radiculopathy and superior pulmonary sulcus tumor.</p><p><b>METHODS</b>Clinical manifestations, physical, and radiological findings of 10 patients, whose main complaints were radiating shoulder and arm pain and later were diagnosed with superior pulmonary sulcus tumor, were reviewed and compared with those of cervical radiculopathy.</p><p><b>RESULTS</b>Superior pulmonary sulcus tumor patients have shorter mean history and fewer complaints of neck pain or limitation of neck movement. Physical examination showed almost normal cervical spine range of motion. Spurling's neck compression test was negative in all patients. Anteroposterior cervical radiographs showed the lack of pulmonary air at the top of the affected lung in all cases and first rib encroachment in one case. The diagnosis of superior pulmonary sulcus tumor can be further confirmed by CT and MRI.</p><p><b>CONCLUSIONS</b>By the method of combination of history, physical examination, and radiological findings, superior pulmonary sulcus tumor can be efficiently differentiated from cervical radiculopathy. Normal motion range of the cervical spine, negative Spurling's neck compression test, and the lack of pulmonary air at the top of the affected lung in anteroposterior cervical radiographs should be considered as indications for further chest radiograph examinations.</p>

Treatment of long unstable femoral intertrochanteric fractures with locking plate and cable rope / 中国骨伤

<p><b>OBJECTIVE</b>To investigate clinical effect of long unstable femoral intertrochanteric fractures with locking plate and cable rope.</p><p><b>METHODS</b>From June 2004 to June 2010, twenty-six elderly patients with long unstable femoral intertrochanteric fractures were treated locking plate and cable rope fixation,included 16 males and 10 females with an average age of (58.23 +/- 4.45) years ranging from 50 to 65 years. There were 22 cases for traffic accident, 10 of them for traffic accident with other injury; 4 cases for falling injury. According to Evans classification, 21 cases were in type I,among them 8 in type Ia, 10 in type Ib,2 in type Ic, 1 in type Id; the other 5 cases were type Hrd. Hip function scores were recorded to evaluate the treatment outcomes by Harris hip function score system.</p><p><b>RESULTS</b>Twenty-six cases were followed-up for 9 to 18 months (means 15 months). The operations were successful. All the patients received functional training for walking without weight loading from 7 to 14 days after operation, and walking gradually in weight loading from 6 weeks after operation,gradually fully weight loading from 12 weeks. The Harris hip function score were 77.31 +/- 13.97, involving pain 39.79 +/- 6.54, function 31.08 +/- 9.45, deformity and activity 3.85 +/- 0.46. The clinical results were excellent in 10 cases, good in 13, fair in 3.</p><p><b>CONCLUSION</b>Locking plate and cable rope is suiteable for the treatment of senile long femoral intertrochanteric fractures of every Evans type, especially benefit for osteoporosis patients.</p>

Effect of tissue factor in extravascular migration of fibrosarcoma cells / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate the effect of tissue factor (TF) in extravascular migration of fibrosarcoma cells and hematogenous metastasis.</p><p><b>METHODS</b>The expression of tissue factor in fibrosarcoma HT1080 cells was analyzed by flow cytometry. The extravascular migration of fibrosarcoma cells was observed in a constructed monolayer vascular endothelial cells and extra-cellular matrix model.</p><p><b>RESULT</b>Tissue factor was highly expressed in HT1080 cells. HT1080 migrated and passed through the monolayer vascular endothelial cells to the collagen gel in a time-dependent manner. Anti-TF antibody inhibited extravascular migration of fibrosarcoma cells and the inhibition was concentration-dependent (P<0.05).</p><p><b>CONCLUSION</b>Tissue factor may enhance hematogenous metastasis through extravascular migration of fibrosarcoma cells.</p>

Pedicle screw placement in the thoracic spine: a randomized comparison study of computer-assisted navigation and conventional techniques / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the accuracy of computer-assisted pedicle screw installation and its clinical benefit as compared with conventional pedicle screw installation techniques.</p><p><b>METHODS</b>Total 176 thoracic pedicle screws placed in 42 thoracic fracture patients were involved in the study randomly, 20 patients under conventional fluoroscopic control (84 screws) and 22 patients had screw insertion under three dimensional (3D) computer-assisted navigation (92 screws). The 2 groups were compared for accuracy of screw placement, time for screw insertion by postoperative thin-cut CT scans and statistical analysis by X(2) test. The cortical perforations were then graded by 2-mm increments: Grade I (good, no cortical perforation), Grade II (screw outside the pedicle less than 2 mm), Grade III (screw outside the pedicle larger than 2 mm).</p><p><b>RESULTS</b>In computer assisted group, 88 (95.65%) were Grade I (good), 4 (4.35%) were Grade II (less than 2mm), no Grade III (larger than 2 mm) violations. In conventional group, there were 14 cortical violations (16.67%), 70 (83.33%) were Grade I (good), 11 (13.1%) were Grade II (less than 2 mm), and 3 (3.57%) were Grade III (larger than 2 mm) violations (P less than 0.001). The number (19.57%) of upper thoracic pedicle screws ( T(1)-T(4) ) inserted under 3D computer-assisted navigation was significantly higher than that (3.57%) by conventional fluoroscopic control (P less than 0.001). Average screw insertion time in conventional group was (4.56+/-1.03) min and (2.54+/-0.63) min in computer assisted group (P less than 0.001). In the conventional group, one patient had pleura injury and one had a minor dura violation.</p><p><b>CONCLUSIONS</b>This study provides further evidence that 3D computer-assisted navigation placement of pedicle screws can increase accuracy, reduce surgical time, and be performed safely and effectively at all levels of the thoracic spine, particularly upper thoracic spine.</p>

Radiation exposure to spine surgeon: a comparison of computer-assisted navigation and conventional technique / 中国骨伤

To analyze the radiation exposure of surgeon in spine surgery and compare computer-assisted navigation and conventinal technique. While performing spine surgery, the surgeon is exposed to a significant amount of radiation. Spinal surgeons should be considered as workers of radiational occupation accordingly. Methods of reducing radiation exposure should be strongly recommended. Comparing with conventional fluoroscopic technique,the computer-assisted navigtion can reduce surgical time, radiation exposure, and has become an increasingly accepted and practiced from of intraoperative spinal navigation.

Mechanism of endothelial Rho/Rho kinase in extravascular migration of fibrosarcoma cell / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the mechanism of endothelial Rho/Rho kinase in extravascular migration of fibrosarcoma cell.</p><p><b>METHODS</b>We used an in vitro model of fibrosarcoma cell transmigration across a monolayer of human umbilical vein endothelial cell (HUVEC) cultured on collagen gel to observe extravascular migration of fibrosarcoma cells, and then calculated the electrical resistance of HUVEC monolayer and endothelial myosin light chain (MLC) phosphorylation in extravascular migration of fibrosarcoma cells.</p><p><b>RESULTS</b>Fibrosarcoma cells migrated through endothelial cells into collagen gel. The electrical resistance of a HUVEC monolayer reduced and endothelial MLC phosphorylation enhanced in the extravascular migration of fibrosarcoma cells. Endothelial Rho inhibitor (C3 transferase) and Rho kinase inhibitor (Y-27632) inhibited the extravascular migration of fibrosarcoma cells and inhibited the reduction of electrical resistance of a HUVEC monolayer and the enhancement of endothelial MLC phosphorylation in extravascular migration of fibrosarcoma cells.</p><p><b>CONCLUSION</b>Endothelial Rho/Rho kinase may regulate fibrosarcoma cell transendothelial migration through MLC phosphorylation.</p>

Protective effect of velvet antler polypeptide (VAP) on rats with the spinal cord injury / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the protective effect of antler polypeptide on the rats with spinal cord injury (SCI).</p><p><b>METHODS</b>The model rats were treated with different doses of antler polypeptide, and its effect on motor function, ethology and pathological changes of spinal cord of the rats observed.</p><p><b>RESULTS</b>Seven days after treatment with different doses of antler polypeptide, rat's motor activity was recovered in some extent. Significant difference (P < 0.001)was found between the antler polypeptide treatment group and operation group. The effect could be enhanced by increase of the doses. We observerd the effect on the pathological change of spinal cord in rat, and found the tissue edema and inflammatory infiltration were relieved after treatment with different doses of antler polypeptide, especially in the dose of 15 mg antler polypeptide.</p><p><b>CONCLUSION</b>Antler polypeptide can promote the motor function recovery in SCI rats, and its action is dose-dependent.</p>

Therapeutic effects of small interfering RNA targeting MDM2 on human osteosarcoma cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the inhibitory effect of the small interfering RNA targeting mdm2 gene on the growth of osteosarcoma cells.</p><p><b>METHODS</b>PGCsilencerTM-mdm2 siRNA was constructed and transfected into the osteosarcoma cell line U2OS cells. The inhibitory effects on mdm2 were determined by RT-PCR and Western blot analysis. The cell growth activity was determined by MTT assay, and the cell apoptosis was examined by flow cytometry. The therapeutic effects of simdm2 was assessed on the nude mouse model of transplanted tumor.</p><p><b>RESULTS</b>The simdm2 plasmid was successfully constructed. After simdm2 being transfected into the U2OS cells, the expressions of mdm2 gene and protein were significantly inhibited. The ability of cell growth activity decreased greatly and cell apoptosis occurred apparently. There was no significant difference between the negative control group and non-transfected group. The growth of xenograft tumor in simdm2 transfected nude mice was inhibited and the expressions of mdm2 gene and protein were down-regulated remarkably.</p><p><b>CONCLUSION</b>siRNA targeting mdm2 gene inhibits the mdm2 expression in osteosarcoma U2OS cells and the growth of osteosarcoma in nude mice.</p>