The aseptic loosening of prosthetic components after the total hip arthroplasty (THA) is a possible clinic problem which needs resolving by orthopedic surgeons. Timely clinical and radiological examinations and ana lyses of the signs and progression of the loosening after THA will play a critical role in prevention and treatment to the aseptic loosening of prosthetic components. The article puts forward the principle for correct evaluation of the aseptic loosening after it reviews and analyzes the existing clinical and radiological examination methods of detecting the loosening. [

BACKGROUND:Electrospinning preparation for the tissue engineering scaffold materials is an extremely promising technology.
OBJECTIVE:To review the progress of electrospinning technology in different fields and its main problems in the current application.
METHODS:We searched Medline and CNKI databases for articles published from 2000 to 2013 using the keywords of“electrospinning, tissue engineering”in English and Chinese.
RESULTS AND CONCLUSION:The structure of non-woven cloth materials made by this technology is similar to the extracel ular matrix, which has high surface area and control able mechanical properties. Electrospinning materials have been widely applied in the tissue engineering field, especial y in the biodegradable materials and high biocompatibility molecular polymer synthesis process. Electrospinning has been developed rapidly in tissue engineering applications, especial y in the choice of materials or electrospinning technique combined with different technologies. Different morphological structures and properties of the materials can be wel combined by using electrospinning technology. A series of new polymers were successful y incorporated into a tissue engineering scaffold as the matrix for cel proliferation and regeneration, but there are some important issues to be solved, including how to control the interaction between the scaffold and the biological system that is to achieve the infiltrative growth of cel s, how to control the pore size, mechanical properties and toxicity. This technology clinical y applied in biomedicine stil requires further research, especial y in vivo studies.

BACKGROUND: During the hip replacement, selection of prosthesis often depends on patients' bone condition. There has been no gold standard for selection of prosthesis. It will be of scientific significance to select femoral prostheses implanted under different bone densities through three-dimensional finite element analysis and simulated contrast mechanical tests.OBJECTIVE: Three-dimensional finite element analysis was employed to select femoral prostheses according to different bone densities, and simultaneously simulated contrast mechanical tests were performed to determine the age criteria regarding the selection of femoral prosthesis during the hip replacement.DESIGN, TIME AND SETTING: An open experiment was performed at the Second Department of Orthopedics, First Clinical Hospital of Jilin University and Institute of Biomechanics, Jilin University between September 2006 and May 2007.MATERIALS: Freshly adult femoral specimens were harvested from cadavers.METHODS: Three-dimensional finite element models of femur were established using Solidworks software. Following the known formula, the bone density and elastic modulus at different age brackets were calculated and input into the computer. The human one-foot standing condition was simulated and pressure was loaded on the reconstructed femoral models.MAIN OUTCOME MEASURES: Some biomechanical characteristics of uncemented and cemented femoral prostheses, such as the distress distribution and initial micromovement at different bone densities, were measured.RESULTS: Relatively well-distributed whole distress and slight initial micromovement of uncemented femoral prostheses were found in male patients at 30-60 years old and in female patients at 40-55 years old. Symptoms of cemented femoral prostheses the same as the uncemented femoral prostheses were present in male patients at 60-70 years and in female patients older than 55 years old.CONCLUSION: Results of three-dimensional finite element analysis and simulated contrast mechanical tests suggest that uncemented femoral prostheses provide better therapeutic effects in male patients younger than 60 years and in female patients younger than 55 years than cemented femoral prosthesis.

BACKGROUND:Standard artificial prosthesis does not well match to patients' skeleton due to absolute individuation,while the difference between them does not keep the stabilization of artificial joint for a long term.OBJECTIVE:To construct three-dimensional models of custom-made femoral prosthesis by using computer-aided design and to verify whether custom-made femoral prosthesis is superior to popular femoral prosthesis via simulating and contrasting mechanical study.DESIGN,TIME AND SETTING:Opening study was performed in the Orthopaedics Institute of the First Clinical Hospital and the Biomechanics Institute,Jilin University between September 2006 and May 2007.MATERIALS:One fresh femur was derived from adult corps.METHODS:Two-dimensional images of the fresh femur was obtained by using total-length CT scanning and processed with computer edge recognition and three-dimensional contour extraction software to identify outer and inner contour of bone cavity,extract contour data of bone cavity and prosthesis,and construct three-dimensional models of femur and custom-rhade femoral prosthesis.SolidWorks software was used to establish three-dimensional prosthetic models in common biological and bone cement types; moreover,bone-cement,biological,and custom-made femoral prosthesis were replaced via simulating clinical surgery.MAIN OUTCOME MEASURES:Standing on single or double feet was simulated to measure stress distribution,interface stress,and primary micromotion of femoral prosthesis in the three types.RESULTS:Edge extracting was replaced by Canny calculator,characterizing by stable running,credible outcome,and consistent with the primary request.Stress,femoral stress,interface stress,and primary micromotion of custom-made femoral prosthesis were significantly lower than biological and'bone-cement femoral prosthesis (P ＜ 0.01).CONCLUSION:The computer-aided design is reliable to perform the assistant design of prosthesis; furthermore,biomechanical properties of the custom-made femoral prosthesis are superior to those of popular femoral prosthesis.

BACKGROUND:Acetabular cup orientation is critical for preserving the range of motion and preventing dislocation of the prosthesis. Cup malpositioning may result in an increased polyethylene wear rate,pelvic osteolysis and acetabular migration (aseptic loosening).There are no definite criterion for the orientation of the acetabular cup.OBJECTIVE:To explore the relationship between acetabular cup Position and the load distribution within the acetabulum and to confirm an optimal range of cup position.thereby providing a theoretical criterion from a biomechanical aspect for proper cup implantation in clinical work.DESIGN:Repeated measurements.SETTING:Second Department of Orthopaedics in the First Clinical Hospital of Jilin University.MATERIALS: One healthy male adult fresh Cadaveric pelvis was offered by the Department of Anatomy in Jilin University.METHODS:This experiment was carried out at the Institute of Orthopaedics in the First Clinical Hospital of Jilin University,and the Institute of Biomechanics in Jilin University from September 2005 to May 2006.Cadaveric pelvic was scanned with spiral CT,and then the two-dimensional images were evaluated using GE medical systems software and the outline of the pelvis was identified by the edge detective estimation.Pelvic coordinate data were put into the computer to build up a three-dimensional (3D) finite element model of the pelvic using Solidworks software.A P48 non-cemented cup from Tianjin Huabei Medical Instrument Factory was used,and the 3D measurement of the cup was carried out by CLY single-arm 3D measurement apparatus,which was made in Testing Technology Institute of China.The measurement data were transferred into computer.Through the CAD SliodWorks2003 software,the 3D model of the cup was automatically reconstructed. Afterwards, one-foot standing position was simulated to conduct the loading and constraint of the model,the Mises and shear force distributing of the cup were analyzed,forecasting the mechanical risk of prosthetic failure.MAIN OUTCOME MEASURES:The evaluation of Mises stress and shear force distributions under different cup positions.RESULTS:In the 3D finite element modeI of human pelvis.the number of total nodes was 103043 and the number of total elements was 69271.Abduction angle did not affect the Mises and shear force distributions between the range of 40°-50°(P>0.05).However,significant affects appeared in Mises and shear force once the abduction angle was<35°or>50°.The change of the cup anteversion within 5°-30°would not affect the Mises and shear forces in the acetabulum(P>0.05).CONCLUSION:A uniform load distribution on the cup-bone interface can be obtained when the cup abduction angle is from 40°to 50°.The change of the cup anteversion angle can not affect the load distribution in the acetabulum,therefore the cup abduction range of 40°-50°can be confirmed as the safe range for cup implantation.

BACKGROUND: Bone metabolism disorder happens in diabetic environment, bone defects in which are difficult to repair. Study addressing osteogenic property of adipose-derived stroma cells (ADSCs) in diabetic environment provides theoretical basis for its application in certain environment.OBJECTIVE: To explore the effects of high glucose (HG) and advanced glycation end-products (AGEs) on osteogenic capacity of human ADSCs. METHODS: 100 mg/L AGEs and 27.5 mmol/L HG were used to simulate in vitro diabetic environment and intervened ADSCs osteogenic differentiation. The cells were divided into 4 groups, with 6 samples in each group. The expression of type Ⅰ collagen was examined by fluorescent immunofluorescence at 21 days after osteogenic induction. The number of calcification nodes was counted under contrast phase microscopy at 14, 21 and 28 days. RESULTS AND CONCLUSION: Fluorescent quantitation scan showed that the type Ⅰ collagen amount of the AGEs+HG treated group was 2.76 times lower than that of the control group. AGEs+HG reduced the number of ADSCs calcification nodes compared with the control, HG, and AGEs groups, the differences were statistical significant (P < 0.01). AGEs and HG exposure inhibit the cognate osteogenic differentiation of ADSCs, which suggest that AGEs and HG are unfavorable factors that reduce ADSCs osteogenic ability.

ObjectiveTo investigate the relationship between the expression of ER,PR,HER-2,Ki-67 and the effective rate of neoadjuvant chemotherapy (NAC) and to study the influence of NAC on expression of ER,PR,HER-2 and Ki-67 in breast cancer.Methods41 patients of breast cancer were performed 2 to 6 cycles of CAF chemotherapy.The expression of ER,PR,HER-2 and Ki-67 was detected by SP immunohistochemical method before and after NAC.ResultsThe effective rate of NAC was 73.17％ (30/41).The positive and negative efficiency rate was 67.86％ (19/28) vs 84.62％ ( 11/13 ) for ER,64.29％ (9/14) vs 77.78％ (21/27 ) for HER-2,70.00％ (14/20) vs 76.19％ ( 16/21 ) for Ki-67.The difference had no statistical significance (P ＞0.05).The positive and negative efficiency rate was 66.67％ (16/24) vs 82.35％ (14/17) for PR.The difference had statistical significance (P ＜ 0.05 ).The expression of ER,PR,HER-2 and Ki-67 before and after NAC changed in 10,8,3 and 9 cases respectively.The difference had no statistical significance (P ＞ 0.05).ConclusionsNAC has no influence on the expression of ER,PR,HER-2 and Ki-67.Patients with PR negative are more sensitive to NAC.The expression state of PR can be used to predict the curative effect of NAC.The expression state of ER,HER-2 and Ki-67 has no significant correlation with NAC.

Objective To investigate the short-term surgical effect and complications of posterior dislocation of the hip with femoral head fractures.Methods Twenty-two patients with posterior dislocation of the hip with femoral head fractures treated surgically from December 1999 to December 2008 were reviewed retrospectively.All the patients were males aged from 23-52 years (mean 39.2 years).According to Pipkin classification,fractures were type Ⅰ in nine cases (41％),type Ⅱ in seven (32％),type Ⅲ in two (9％) and type Ⅳ in four (18％).Different surgical approaches and treatment methods were employed together with a periodic follow-up.Harris score and Thompson & Epstein score were used as measurement standard in postoperative clinical and radiological follow-up.Postoperative complications were analyzed as well.Results All the patients were followed up for mean 36 months.Clinical outcome as assessed by Harris criteria was excellent in 10 cases,good in seven,fair in two and poor in three,with excellent-good rate of 77％.Complications included femoral head avascular necrosis in four cases and traumatic arthritis in six.Heterotopic ossification of the hip did not occur.One case complicated with idiopathic injury of sciatic nerve was recovered at one year after operation.Conclusions Posterior dislocation of the hip with femoral head fractures should be operated as soon as possible.Operational modalities should depend on the type of fractures for the sake of reducing complications.

BACKGROUND:Magnesium al oy as a fracture fixation material has mechanical properties similar to the bone, good biocompatibility and biodegradability, but its rapid degradation rate in body fluids becomes a clinical bottleneck. Therefore, the use of surface treatments to improve its corrosion resistance is important.
OBJECTIVE:To use magnetron sputtering technology and alkali heat treatment technology in the preparation of coating characterized as both corrosion resistance and biological activity.
METHODS:First, we prepared Mg-Zn-Mn al oy using the smelting technology, and prepared a dense coating on the al oy surface by the magnetron sputtering technique. Then, we processed the coating surface using an alkaline solution, and studied the corrosion behavior of the coating by use of simulated body fluid experiments. We speculated the biological activity of the coating by measuring the content of calcium and phosphorus from the surface products.
RESULTS AND CONCLUSION:We prepared the coating, which had both corrosion resistance and biological activity, on the surface of magnesium al oy by use of magnetron sputtering and alkali heat treatment technology. After soaking in the simulated body fluid for 24 hours and 168 hours, the deposition of the coating surface contained Ca, P products. Ca/P ratios were 1.54 and 2.11, respectively, closed to the bone-phosphate Ca/P ratio. The coating surface formed 5-10μm pitting after 24 hours of immersion, and the pitting grew up with the immersion time. The pitting was enlarged to 100-800μm after 168 hours.