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BACKGROUND:Irreducible femoral neck fracture was difficult to obtain anatomic reduction.As a new type of internal fixation,the femoral neck system is still blank for the treatment of non-anatomical reduced femoral neck fractures. OBJECTIVE:To explore the biomechanical stability of femoral neck system internal fixation under nonanatomical reduction in the treatment of femoral neck fractures based on finite element analysis. METHODS:CT data of the hip joint of a healthy female adult were obtained.Anatomical reduction of femoral neck fracture models with Pauwels angles of 30°,50°,and 70° were established using Mimics 21.0,Geomagic Wrap 2021,and SolidWorks 2020.The fracture proximal ends of the three anatomical reduction models were shifted upward by 2 mm along the fracture line,and three positive buttress models with different Pauwels angles were obtained.In the same way,three negative buttress models were acquired by shifting downward by 2 mm.SolidWorks 2020 was used to make the femoral neck system internal fixation,and the nine femoral neck fracture models were assembled with the femoral neck system.Then Ansys 19.0 was used for finite element analysis.The displacement distribution and maximum displacement,stress distribution and maximum stress of the femur and femoral neck system were recorded under 2100 N stress. RESULTS AND CONCLUSION:(1)When Pauwels angles were 30°,50°,and 70°,the maximum stresses of the femoral neck system appeared to be concentrated at the junction of the sliding hip screw and anti-rotation screw.The maximum femur stresses appeared to be concentrated in the medial cortex of the femur.The maximum displacement was concentrated at the upper of the femoral head and femoral neck system.(2)When Pauwels angles were 30° and 50°,the maximum displacement and maximum stress of the femoral neck system and femur were:negative buttress>anatomical reduction>positive buttress.(3)When Pauwels angle was 70°,the maximum displacement and maximum stress of the femoral neck system were:negative buttress>anatomical reduction>positive buttress;the maximum displacement and maximum stress of the femur were:negative buttress>positive buttress>anatomical reduction.(4)With the increase of Pauwels angle,the biomechanical advantage of the positive buttress was weakening.However,it was better than a negative buttress.When Pauwels angle was 30°,positive buttress was more stable than anatomical reduction.When Pauwels angle was 50°,the biomechanical difference between positive buttress and anatomical reduction became smaller.When Pauwels angle was 70°,the stability of anatomical reduction was slightly better than positive buttress.(5)If it was difficult to achieve anatomical reduction of femoral neck fracture during operation,but the positive buttress had been displaced within 2 mm,the femoral neck system could be used to offer stable mechanical fixation.It is necessary to avoid negative buttress reduction.
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Objective:To investigate the effects of tantalum coating on adhesion, proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro. Methods:In this study, BMSCs were extracted from 6 6-week-old rats and cultured in vitro to the third generation. Tantalum coating was manufactured on Ti6Al4V by chemical vapor deposition. The cells were identified by flow cytometry before they were induced with different mediums for osteogenesis, chondrogenesis and adipogenesis. The adhesion, proliferation and osteogenic differentiation of BMSCs were detected with fluorescence staining, Cell Counting Kit-8 (CCK8) assay and Q-PCR, respectively. Recorded and compared were the adhesion rate, proliferation rate, and expression of osterix (OSX), Runt-related transcription factor 2 (RUNX2), osteonectin (OSN) and osteopontin (OPN) of BMSCs on the surface of titanium alloy round plates (the Ti6Al4V group) and of tantalum coating round plates (the Ta group). Results:The flow cytometry revealed CD44 (94.55%), CD90 (95.01%) and CD34 (0.06%). Alkaline phosphatase (ALP) staining was positive after osteogenic induction for 14 days; Alizarin red staining showed calcified nodules after osteogenic induction for 21 days; oil red O staining was positive after adipogenic induction for 21 days; alcian blue staining found chondrogenic ability after chondrogenic induction for 21 days. Laser confocal microscopy showed that the BMSCs grew in patches aggregated and closely linked on the surface of titanium alloy round plates (in the Ti6Al4V group) and of tantalum coating round plates (in the Ta group). More BMSCs adhered on the tantalum coating plates than on the titanium alloy plates and exhibited better ductility. The proliferation rates of BMSCs on tantalum coating were significantly faster than those on titanium alloy after 1, 3, 5 and 7 days of co-culture in vitro ( P<0.05).Q-PCR showed that tantalum coating promoted the expression of OSN and OPN after 7 days of culture significantly higher than titanium alloy did ( P<0.05).After 21 days of co-culture in vitro, tantalum coating enhanced the expression of OSX, RUNX2, OSN and OPN significantly higher than titanium alloy did ( P<0.05). Conclusion:Compared to titanium alloy which is used for conventional orthopedic implants, tantalum coating can observably promote adhesion, proliferation and osteogenic differentiation of BMSCs.
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Objective@#To investigate the early diagnosis and treatment options for steroid-induced osteonecrosis of the femoral head (SONFH).@*Methods@#Retrospective analysis was conducted in 73 patients with unilateral SONFH from January 2010 to June 2017. There were 27 males and 46 females, aged 34.26±10.35 years (range, 20-45 years). The following type of cases were included, 21 cases of ARCO I, 24 cases of IIa, 8 cases of IIb, 18 cases of IIc and 2 cases of IIIa. Patients with ARCO I were limited in weight and were treated with low molecular weight heparin sodium and ginkgo dharma drugs after excluding bleeding risk. Core decompression was performed in patients with ARCO IIa and IIb vascularized greater trochanter bone transfer was conducted in patients with IIc and IIIa. During the follow-up duration, when the ARCO I progressed to ARCO IIa and IIb, the core decompression was performed. When the ARCO IIa and IIb progressed to the ARCO IIc or IIIa, the vascularized greater trochanter bone transfer was conducted. Vascularized greater trochanter bone combined with the tantalum rod was implanted in ARCO IIIb. The femoral head reconstruction with the larger trochanter bone flap or joint replacement was performed in ARCO IIIc and above. The Harris hip score was used to evaluate the clinical outcomes. The femoral head survival curve of SONFH was drawn with the end of joint replacement.@*Results@#All 73 patients were followed up for an average of 29 months (range, 18 to 48 months). After treatment of 21 patients with ARCO I, a total of 14 (67%) patients had no ARCO staging progress. After 6 months, three patients progressed to ARCO IIb and 4 patients progressed to ARCO IIc. All 32 patients with ARCO IIa and IIb were treated, of which 25 (78%) did not progress but 4 patients progressed to ARCO IIIa at 6 months. Only one patient progressed to ARCO IIIb at 6 months, and 2 patient progressed to ARCO IIIc at 12 months. There were 18 patients with ARCO IIc underwent treatment, of which 14 patients (78%) did not progress but 2 patients progressed to ARCO IIIa at 6 months and 2 patients progressed to ARCO IIIc at 24 months and to ARCO IV at 42 months, respectively. Two patients of ARCO IIIa, 1 patient did not progress and the other one progressed to ARCO IV at 36 months. The Harris hip score was 90.48±5.36 before treatment and 91.76±8.19 at the last follow-up. The difference was not statistically significant (t=1.231, P=0.402). The Harris hip score of patients with ARCO IIa and IIb in creased from 75.22±8.30 to 84.47±16.77 with statistically significant difference (t=5.624, P<0.001). The Harris hip score of patients with ARCO IIc and IIIa increased from 59.80±9.24 to 77.75±20.75 with statistically significant difference (t=12.033, P<0.001). Four patients eventually underwent arthroplasty. The femoral head survival rate was 98.6% at 2 years and 94.5% at 4 years.@*Conclusion@#The SONFH can be diagnosed early by screening, and is treated by different reserving hip methods according to severe stages. The short-term clinical effects are satisfied.
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BACKGROUND: The imaging methods of evaluating the volume of necrotic femoral head are based on Kerboul angle and necrosis index revealed on X-ray, as well as CT and MRI three-dimensional reconstruction, but the accuracy of each method is different, and none is widely accepted. Additionally, the association of the volum and degree of necrotic femoral head with the status of blood supply to the femoral head remain unclear. OBJECTIVE: To evaluate the accuracy of each imaing method for assessing different stages of femoral head necrosis, and to confirm a convenient method used for measuring the volum of necrotic femoral head. METHODS: This diagnostic in vivo animal trial was finished in the Affiliated Zhongshan Hospital of Dalian University, Liaoning Province, China. The canine models of steroid-induced necrosis of femoral head were prepared, and received CT and MRI examinations, followed by three-dimensional reconstruction combined with Micro-CT to make accuratediagnosis; the degree of necrotic femoral head and its association with the status of blood supply were evaluated throughangiography and histopathological examination. All above outcome measures were compared with the Association Research Circulation Osseous to testify the consistency of this precise method with traditional methods. The experiment follows the national guidelines for the Care and Use of Laboratory Animals, and Consensus author guidelines on animal ethics and welfare by the international Association for Veterinary Editors (IAVE). The article was prepared in accordance with the Animal Research: Reporting of In Vivo Experiments Guidelines (ARRIVE Guidelines). RESULTS AND CONCLUSION: The aim of the study is to obtain a accurate measurement method by detecting different stages of osteonecrosis using different imaging techniques, which enables surgeons make exact diagnosis and clinical stage of osteonecrosis, thus desiging standardized treatment program.
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Objective To analyze retrospectively the clinical efficacy that the application with vascularized greater trochanter to reconstruct the collapse of femoral head necrosis.Methods Followed-up the data of 21 patients who underwent reconstruction of the femoral head from January,2008 to December,2012,by this we made the clinical and radiological assess,Harris hip scoring system was used to evaluate the situation of hip function.All patients were followed up regularly for X-ray film (after 3 months,6 months and then be reviewed once a year),by the film we assessed the bone healing and repair of the femoral head,and determined whether had the progress in phases.The clinical survival was decided by receiving or not the arthroplasty.Results All 21 patients were followed up for 24-72 months,with an average of 47 months.The postoperative Harris hip score was 82.8 ± 7.1 points,compared with the preoperative,the score improved significantly (average 52.4 ± 4.3 points for preoperative),the difference was statistically significant (P ＜ 0.05).Based on Ficat stage for osteonecrosis,8 patients in this group had progress after 24 to 48 months (mean 33 months),whose femoral heads got collapse worsened.The radiographic success rate was 61.9％.Six cases received arthroplasty in 18 to 48 months (mean 34 months) due to progressive collapse of the femoral head or severe hip pain,or both.FicatⅢ contained 25％ (4 hips),and Ⅳ had 40％ (2 hips),the clinical survival rate was 71.4％.Conclusion The application with vascularized greate.r trochanter transfer coverage to rebuild the collapse of the femoral head in patients with osteonecrosis is a good way.It' s worthy to be applied.
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Objective To investigate the clinical effect of the iliac periosteal flap with ascending branch of lateral femoral circumflex artery for the treatment of Legg-Calvé-Perthes disease.Methods Followed-up 18 patients with Legg-Calvé-Perthes disease who had undergone the treatment of iliac periosteal flap with ascending branch of lateral femoral circumflex artery from January,2008 to May,2012 in our hospital.Minimum follow-up time was from 24 to 60 months,and the average time was 38 months.The followed-up period ended in May,2014.Assessed the effect of surgery by X-ray,clinical examination and Harris scoring system.Results Sixteen patients had good healing with iliac periosteal flap according to X-ray show.Their epiphyseal height recovered and the femoral head rounded gradually.Two cases became flat and collapse.The result of excellent and good rate was 88.9％ by Mose method combined with the results of X-ray.The average Harris hip score improved from 72.3 ± 4.9 points preoperatively to 91.3 ± 2.4 points postoperatively.The difference of the result was statistically significant (P ＜ 0.05).Conclusion The transfer of iliac periosteal flap with ascending branch of lateral femoral circumflex artery is an effective treatment for Legg-Calvé-Perthes disease.
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BACKGROUND:Porous tantalum rods, possessing high porosity and highly similar elastic modulus to the trabecular bone, not only can provide effective mechanical support for the femoral head, but also can enhance revascularization in the areas of necrosis, reduce stress shielding, and provide guarantee for bone ingrowth in necrotic area. OBJECTIVE:To investigate the attachment and proliferation of bone marrow mesenchymal stem cells on the surface of porous tantalum rod. METHODS:The purified bone marrow mesenchymal stem cells which were separated from canines were seeded on the surface of porous tantalum rod by the celldensity of 1.5×109/L. cellattachment and proliferation was observed under phase microscope and scanning electron microscope at 5, 10 and 15 days under co-cultured condition. RESULTS AND CONCLUSION:(1) Inverted microscope:Within 1-5 days after co-culture, the cells began to proliferate, and less cells were found near the tantalum rod, but more cells far from the rod. At 6-10 days after co-culture, the cells increased significantly and gradual y migrated to the rod, and even some cells attached to the edges of the rod. After 14 days, the cells were interconnected to form a film, packing the surrounding and dents of the tantalum rod. cells were visible to agglomerate and cellcalcification occurred. (2) Scanning electron microscope:At 5 days after co-culture, no celladhesion appeared on the the tantalum rod surface. At 10 days after co-culture, the cells scattered on the surface of tantalum rod, but there was no interconnection between them. After 15 days, cells were polygon shaped and connected into pieces. It could be seen that the cells secreted large amounts of col agen fibers, and the cells that were fusiform and polygon shaped were surrounded by a great amount of extracellular matrice. Bone marrow mesenchymal stem cells appear to have good adhesion and proliferation capability on the surface of tantalum rod.
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Objective To investigate the incidence of osteonecrosis of the femoral head (ONFH) in divers of Dalian.Methods From January 2010 to December 2010,all registered 855 divers in Dalian were enrolled in this study.All divers underwent a unified medical examination and a questionnaire including height,weight,blood pressure and hip inspection.Radiological examination (anteroposterior and frog position)was used for all divers.Suspicious persons with hip pain but normal X-ray performance were confirmed by MRI.Results Sixty-eight divers were confirmed as ONFH,and the incidence of ONFH in divers of Dalian was 7.95％.According to the Ficat classification,12 patients (12 hips) were in Phase 1,40 patients (47 hips)in phase Ⅱ,3 patients (3 hips) in phase Ⅲ,13 patients (15 hips) in phase Ⅳ.The mean age of divers was 32.6+5.5 years (range,18-55 years).The onset ages of most patients ranged from 30 years to 50 years,accounted for 83.82％ (57/68).Among all patients,primary school education accounted for 10.58％ (38/359),junior high school education 6.28％ (28/446),high school education 4.26％ (2/47),university education 0 (0/3); seniority less than 5 years accounted for 4.55％ (20/440),6-10 years 9.69％ (28/289),11-15 years 13.04％ (12/92),16-20 years 21.05％ (4/19),more than 20 years 26.67％ (4/15); self-employed accounted for 11.88％ (19/160),private enterprise 8.41％ (38/452),and national enterprise 4.53％ (11/243).Conclusion The incidence of ONFH is high in divers of Dalian,which is different in terms of age,seniority,level of education,enterprise nature.