Risk factors and clinical manifestations of head-neck wear in artificial hip joints / 中华骨科杂志

At present, total hip arthroplasty (THA) is the primary treatment for hip diseases such as femoral head necrosis and developmental dysplasia of the hip. It has good effects in reducing pain and improving joint function. The appearance of modular hip prosthesis facilitates adjustment of limb length and femoral offset. However, the wear between the interface of hip prosthesis can lead to inflammatory pseudotumor, osteolysis and other adverse reactions. To explore the risk factors of wear between hip prosthesis interface is helpful to improve the design and manufacturing concept of the product, improve the product performance, help surgeons optimize the operation technology and reduce the impact of human factors on the wear of the prosthesis. Many literatures have reported the mechanism of wear between the head-acetabula interface of prosthesis. The mechanism of wear between the interfaces has been described relatively clearly. In addition to the head-acetabula interface, the wear between the head-neck interface is another major cause of unexplained pain around the joint and prosthesis loosening after hip replacement. Many factors affect head-neck wear. The design of prosthesis (such as prosthesis material and prosthesis taper), surgical technology (such as impact strength and prosthesis mismatch) and patient factors (such as age, gender and activity) have important impact on head-neck wear. Adverse reactions caused by head-neck wear have also been widely concerned. However, there is no considerable solution for wear prevention. Thus, we should optimize the design of prosthesis, improve the surgical technology, and guide the rehabilitation of patients to prevent wear. In order to improve the attention of joint surgeons, the present paper reviews the literatures and analyzes the risk factors of head-neck interface wear and the clinical manifestations caused by head-neck wear.

Risk factors and clinical manifestations of head-neck wear in artificial hip joints / 中华骨科杂志

At present,total hip arthroplasty (THA) is the primary treatment for hip diseases such as femoral head necrosis and developmental dysplasia of the hip.It has good effects in reducing pain and improving joint function.The appearance of modular hip prosthesis facilitates adjustment of limb length and femoral offset.However,the wear between the interface of hip prosthesis can lead to inflammatory pseudotumor,osteolysis and other adverse reactions.To explore the risk factors of wear between hip prosthesis interface is helpful to improve the design and manufacturing concept of the product,improve the product performance,help surgeons optimize the operation technology and reduce the impact of human factors on the wear of the prosthesis.Many literatures have reported the mechanism of wear between the head-acetabula interface of prosthesis.The mechanism of wear between the interfaces has been described relatively clearly.In addition to the head-acetabula interface,the wear between the head-neck interface is another major cause of unexplained pain around the joint and prosthesis loosening after hip replacement.Many factors affect head-neck wear.The design of prosthesis (such as prosthesis material and prosthesis taper),surgical technology (such as impact strength and prosthesis mismatch) and patient factors (such as age,gender and activity) have important impact on head-neck wear.Adverse reactions caused by head-neck wear have also been widely concerned.However,there is no considerable solution for wear prevention.Thus,we should optimize the design of prosthesis,improve the surgical technology,and guide the rehabilitation of patients to prevent wear.In order to improve the attention of joint surgeons,the present paper reviews the literatures and analyzes the risk factors of head-neck interface wear and the clinical manifestations caused by head-neck wear.

Electrospinning technology in tissue engineering:how far is it from the successful application in biomedicine? / 中国组织工程研究

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.

Surgical outcome and complications of posterior hip dislocation combined with femoral head fractures / 中华创伤杂志

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.

Expression of ER, PR, HER-2, Ki-67 before and after neoadjuvant chemotherapy and the relation between their expression and the curative effects of neoadjuvant chemotherapy in breast cancer / 中华内分泌外科杂志

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.

Effects of high glucose and advanced glycation end-products on osteogenic differentiation of human adipose-derived stromal cells in vitro / 中国组织工程研究

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.

Finite element analysis of acetabular medial wall displacement osteotomy in adult acetabular dysplasia / 中国组织工程研究

BACKGROUND: Adult acetabular dysplasia in advanced stage combined with hip joint osteoarthritis should undergo total hip replacement. The severity of acetabular lesion is various in different patients, which leads to significantly increased difficulty in reestablishing acetabulum. Acetabular medial wall displacement osteotomy can solve the component of acetabular prosthesis, but the displacement range of the acetabular medial wall following osteotomy is controversial.OBJECTIVE: To look for a suitable displacement range of acetabular medial wall following osteotomy by computer-aided design finite element analysis.METHODS: SolidWorks 2008 software was used to establish three-dimensional models of acetabular dysplasia pelvis. Acetabular medial wall displacement osteotomy was simulated to make acetabular medial wall bone displace from 2 mm bone contact to 7 mm bone contact in the pelvic cavity. One experimental group was set at 1 mm intervals, totally 10 experimental groups. The acetabulum in each group was split into four quadrants. The prosthesis acetabulum-bone interface in each group was analyzed by computer simulation contrast mechanics experiment. The Mises stress and shear stress values were measured between acetabular prosthesis and bone interface.RESULTS AND CONCLUSION: In groups 1, 5, 6, 9 and 10, the Mises stress was unevenly distributed in posterior inferior, anterior superior and anterior inferior quadrants. In groups 2, 3, 4, 7 and 8, the Mises stress was evenly distributed in posterior inferior,anterior superior and anterior inferior quadrants. Of them, the stress was most even in the group 4. In groups 2, 3, 4, 7 and 8, the shear stress was evenly distributed in the above-mentioned three quadrants. The shear stress was lowest in the groups 7 and 8.These indicate that joint force in the acetabulum mainly focused in the posterior superior quadrant. With the displacement of acetabular cup, the contact area of acetabular cup and bone would gradually increase, which finally increased the Mises stress in the contact surface. However, shear stress decreased with displacement of acetabular medial wall. Therefore, the suitable displacement range of acetabular medial wall osteotomy is 1 mm away from the pelvic cavity and 1 mm complete embolism in the pelvic cavity. The optimal position was 1 mm complete embolism in the pelvic cavity.

Three-dimensional finite element analysis of uncemented and cemented femoral prostheses implanted under different bone densities / 中国组织工程研究

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.

A simulative biomechanical experiment on different position of none-cement acetabular components influencing the load distribution around acetabulum / 生物医学工程学杂志

In the present study, a three dimensional finite-element model of the human pelvic was reconstructed, and then, under different acetabular component position (the abduction angle ranges from 30 degrees to 70 degrees and the anteversion ranges from 5 degrees to 30degrees) the load distribution around the acetabular was evaluated by the computer biomechanical analysis program (Solidworks). Through the obtained load distribution results, the most even and reasonable range of the distribution was selected; therefore the safe range of the acetabular component implantation can be validated from the biomechanics aspect.

Computer-aided design and simulated-mechanical study of custom-made femoral prosthesis / 中国组织工程研究

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.

Changes of load distribution on cup-bone interface at the different positions of non-cemented acetabular cup / 中国组织工程研究

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.

Expressions of VEGF and TGF-? in periosteum in patients with congenital pseudarthrosis of tibia / 吉林大学学报(医学版)

Objective To approach the expressions of vascular endothelial growth factor(VEGF) and transforming growth factor-beta(TGF-?) in periosteum in patients with congenital pseudarthrosis of tibia(CPT) and elucidate the pathogenesis possibility.Methods The expressions of VEGF and TGF-? in 19 specimens from patients with CPT were detected by using immunohistochemical method.Ten normal periosteum from the healing site after tibia fracture were taken as negative group;15 fresh periosteum from the close tibia fractures were positive group.Results VEGF and TGF-? expressed in vascular endothelial cytoplasm of periosteum.The expression levels of VEGF and TGF-? of CPT were lower than those in positive group(P0.05).Conclusion The decreasing of expression levels of VEGF and TGF-? in periosteum may be involved in pathogenesis of CPT.

Mechanical properties and biocompatibility of nanometer calcium carbonate/poly (L-lactide) composites / 生物医学工程学杂志

The purpose of this study is to synthesize nanometer calcium carbonate/poly(L-lactide) composites and evaluate its biocompatibility, and mechanical properties. The nanometer calcium carbonate/poly(L-lactide) composites was prepared by the method of solution mixing and cell culture. Its properties were analyzed using, mechanical tests, MTT assay, transmission electron microscope and scanning electron microscope. It was found that the new kind copolymer had good biocompatibility, nanometer calcium carbonate could enhance the strength of the pure poly (L-lactide) matrix. The nanometer calcium carbonate/poly (L-lactide) composites is a promising bioabsorbable material. It is worth further medical research.

The influence of biodegradable polymer on bone and soft tissue / 生物医学工程学杂志

Clinical and research reports concerning orthopedic biodegradable implants were reviewed. The clinical results were analyzed in terms of complications and compatibility. The possible applications of the implants and further research fields were summarized.

Clinical and radiological diagnoses of aseptic loosening of prosthetic components after total hip arthroplasty / 中华创伤骨科杂志

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. [