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OBJECTIVE@#The biomechanical characteristics of three internal fixation modes for femoral subtrochanteric spiral fracture in osteoporotic patients were compared and analyzed by finite element technology, so as to provide the basis for the optimization of fixation methods for femoral subtrochanteric spiral fracture.@*METHODS@#Ten female patients with osteoporosis and femoral subtrochanteric spiral fractures caused by trauma, aged 65-75 years old, with a height of 160-170 cm and a body weight mass of 60-70 kg, were selected as the study subjects. The femur was scanned by spiral CT and a three-dimensional model of the femur was established by digital technology. The computer aided design models of proximal intramedullary nail (PFN), proximal femoral locking plate (PFLP), and the combination of the two (PFLP+PFN) were constructed under the condition of subtrochanteric fracture. Then the same load of 500 N was applied to the femoral head, and the stress distribution of the internal fixators, the stress distribution of the femur, and the displacement of femur after fracture fixation were compared and analyzed under the three finite element internal fixation modes, so as to evaluate the fixation effect.@*RESULTS@#In the PFLP fixation mode, the stress of the plate was mainly concentrated in the main screw channel, the stresses of the different part of the plate were not equal, and gradually decreased from the head to the tail. In the PFN fixation mode, the stress was concentrated in the upper part of the lateral middle segment. In the PFLP+PFN fixation mode, the maximum stress appeared between the first and the second screws in the lower segment, and the maximum stress appeared in the lateral part of the middle segment of the PFN. The maximum stress of PFLP+PFN fixation mode was significantly higher than that of PFLP fixation mode, but significantly lower than that of PFN fixation mode ( P<0.05). In PFLP and PFN fixation modes, the maximum stress of femur appeared in the medial and lateral cortical bone of the middle femur and the lower side of the lowest screw. In PFLP+PFN fixation mode, the stress of femur concentrated in the medial and lateral of the middle femur. There was no significant difference in the maximum stress of femur among the three finite element fixation modes ( P>0.05). The maximum displacement occurred at the femoral head after three finite element fixation modes were used to fix subtrochanteric femoral fractures. The maximum displacement of femur in PFLP fixation mode was the largest, followed by PFN, and PFLP+PFN was the minimum, with significant differences ( P<0.05).@*CONCLUSION@#Under static loading conditions, the PFLP+PFN fixation mode produces the smallest maximum displacement when compared with the single PFN and PFLP fixation modes, but its maximum plate stress is greater than the single PFN and PFLP fixation mode, suggesting that the combination mode has higher stability, but the plate load is greater, and the possibility of fixation failure is higher.
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Humans , Female , Aged , Finite Element Analysis , Biomechanical Phenomena , Fracture Fixation, Internal/methods , Hip Fractures/surgery , Bone Plates , Femur Head , Femoral Fractures/surgeryABSTRACT
The acute combination fractures of the atlas and axis in adults have a higher rate of neurological injury and early death compared with atlas or axial fractures alone. Currently, the diagnosis and treatment choices of acute combination fractures of the atlas and axis in adults are controversial because of the lack of standards for implementation. Non-operative treatments have a high incidence of bone nonunion and complications, while surgeries may easily lead to the injury of the vertebral artery, spinal cord and nerve root. At present, there are no evidence-based Chinese guidelines for the diagnosis and treatment of acute combination fractures of the atlas and axis in adults. To provide orthopedic surgeons with the most up-to-date and effective information in treating acute combination fractures of the atlas and axis in adults, the Spinal Trauma Group of Orthopedic Branch of Chinese Medical Doctor Association organized experts in the field of spinal trauma to develop the Evidence-based guideline for clinical diagnosis and treatment of acute combination fractures of the atlas and axis in adults ( version 2023) by referring to the "Management of acute combination fractures of the atlas and axis in adults" published by American Association of Neurological Surgeons (AANS)/Congress of Neurological Surgeons (CNS) in 2013 and the relevant Chinese and English literatures. Ten recommendations were made concerning the radiological diagnosis, stability judgment, treatment rules, treatment options and complications based on medical evidence, aiming to provide a reference for the diagnosis and treatment of acute combination fractures of the atlas and axis in adults.
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Ankylosing spondylitis (AS) combined with spinal fractures with thoracic and lumbar fracture as the most common type shows characteristics of unstable fracture, high incidence of nerve injury, high mortality and high disability rate. The diagnosis may be missed because it is mostly caused by low-energy injury, when spinal rigidity and osteoporosis have a great impact on the accuracy of imaging examination. At the same time, the treatment choices are controversial, with no relevant specifications. Non-operative treatments can easily lead to bone nonunion, pseudoarthrosis and delayed nerve injury, while surgeries may be failed due to internal fixation failure. At present, there are no evidence-based guidelines for the diagnosis and treatment of AS combined with thoracic and lumbar fracture. In this context, the Spinal Trauma Academic Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate the Clinical guideline for the diagnosis and treatment of adult ankylosing spondylitis combined with thoracolumbar fracture ( version 2023) by following the principles of evidence-based medicine and systematically review related literatures. Ten recommendations on the diagnosis, imaging evaluation, classification and treatment of AS combined with thoracic and lumbar fracture were put forward, aiming to standardize the clinical diagnosis and treatment of such disorder.
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Osteoporotic vertebral compression fracture (OVCF) can lead to lower back pain and may be even accompanied by scoliosis, neurological dysfunction and other complications, which will affect the daily activities and life quality of patients. Vertebral augmentation is an effective treatment method for OVCF, but it cannot correct unbalance of bone metabolism or improve the osteoporotic status, causing complications like lower back pain, limited spinal activities and vertebral refracture. The post-operative systematic and standardized rehabilitation treatments can improve curative effect and therapeutic efficacy of anti-osteoporosis, reduce risk of vertebral refracture, increase patient compliance and improve quality of life. Since there still lack relevant clinical treatment guidelines for postoperative rehabilitation treatments following vertebral augmentation for OVCF, the current treatments are varied with uneven therapeutic effect. In order to standardize the postoperative rehabilitation treatment, the Spine Trauma Group of the Orthopedic Branch of Chinese Medical Doctor Association organized relevant experts to refer to relevant literature and develop the "Guideline for postoperative rehabilitation treatment following vertebral augmentation for osteoporotic vertebral compression fracture (2022 version)" based on the clinical guidelines published by the American Academy of Orthopedic Surgeons (AAOS) as well as on the principles of scientificity, practicality and advancement. The guideline provided evidence-based recommendations on 10 important issues related to postoperative rehabilitation treatments of OVCF.
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The pelvic and acetabular fracture accounts for 3%-8% of all fractures, and is often accompanied with injuries to the bladder, rectum, important nerves and blood vessels. The fatality rate and disability rate are as high as 18%. The treatment of pelvic and acetabular fracture has experienced conservative treatment, surgical treatment and minimally invasive treatment. In recent years, minimally invasive surgery has been widely used in internal fixation of pelvic fracture. The anterior pelvic ring is an important tension bow of the pelvis. For unstable pelvic fracture, the anterior pelvic ring fracture accounts for almost 3/4. The authors review several minimally invasive surgical techniques for anterior pelvic ring fracture, including internal fixation (INFIX), anterior column channel screw internal fixation, pubic symphysis channel screw internal fixation and anterior ring bridge plate osteosynthesis, so as to provide a reference for choice of clinical treatment methods.
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According to the pathological characteristics of symptomatic chronic thoracic and lumbar osteoporotic vertebral fracture (SCOVF), the different clinical treatment methods are selected, including vertebral augmentation, anterior-posterior fixation and fusion, posterior decompression fixation and fusion, and posterior correction osteotomy. However, there is still a lack of a unified understanding on how to choose appropriate treatment method for SCOVF. In order to reflect the new treatment concept and the evidence-based medicine progress of SCOVF in a timely manner and standardize its treatment, the clinical guideline for surgical treatment of SCOVF is formulated in compliance with the principle of scientificity, practicability and advancement and based on the level of evidence-based medicine.
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Since December 2019, the corona virus disease 2019 (COVID-19) caused by the 2019 novel coronavirus (2019-nCoV) has been reported in Wuhan, Hubei Province. Almost 70% of patients susceptible to 2019-nCoV are over age of 50 years, with extremely large proportion of critical illness and death of the elderly patients. Meanwhile, the elderly patients are at high risk of osteoporotic fractures especially osteoporotic vertebral compression fractures (OVCF). During the prevention and control of COVID-19 epidemic, the orthopedists are confronted with the following difficulties including how to screen and protect OVCF patients, how to accurately diagnose and assess the condition of suspected or confirmed COVID-19 patients, and how to develop reasonable treatment plans and comprehensive protective measures in emergency and outpatient clinics. In order to standardize the diagnosis and treatment of OVCF patients diagnosed with COVID-19, the authors jointly develop this expert consensus to systematically recommend the standardized emergency and outpatient screening and confirmation procedures for OVCF patients with suspected or confirmed COVID-19 and protective measures for emergency and outpatient clinics. Moreover, the consensus describes the grading and classification of OVCF patients diagnosed with COVID-19 according to the severity of illness and recommends different treatment plans and corresponding protective measures.
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Since December 2019, the corona virus disease 2019 (COVID-19) caused by the 2019 novel coronavirus (2019-nCoV) has been reported in Wuhan, Hubei Province. Almost 70% of patients susceptible to 2019-nCoV are over age of 50 years, with extremely large proportion of critical illness and death of the elderly patients. Meanwhile, the elderly patients are at high risk of osteoporotic fractures especially osteoporotic vertebral compression fractures (OVCF). During the prevention and control of COVID-19 epidemic, orthopedists are confronted with the following difficulties including how to screen and protect OVCF patients, how to accurately diagnose and assess the condition of OVCF patients with suspected or confirmed COVID-19, and how to develop reasonable treatment plans and comprehensive protective measures in emergency and outpatient clinics. In order to standardize the diagnosis and treatment of patients with OVCF diagnosed with COVID-19, the authors jointly develop this expert consensus. The consensus systematically recommends the standardized emergency and outpatient screening and confirmation procedures for OVCF patients with suspected or confirmed COVID-19 and protective measures for emergency and outpatient clinics. Moreover, the consensus describes the grading and classification of OVCF patients diagnosed with COVID-19 according to the severity of illness and recommends different treatment plans and corresponding protective measures based on the different types and epidemic prevention and control requirements.
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BACKGROUND: Nano-hydroxyapatite/polyamide 66 (nHA/PA66) is a composite used widely in the repair of bone defects. However, this material is insufficient bioactivity. In contrast, D-RADA16-RGD self-assembling peptide (D-RADA16-RGD sequence containing all D-amino acids is Ac-RADARADARADARADARGDS-CONH2) shows admirable bioactivity for both cell culture and bone regeneration. Here, we describe the fabrication of a favorable biomaterial material (nHA/PA66/D-RADA16-RGD). METHODS: Proteinase K and circular dichroism spectroscopy were employed to test the stability and secondary structural properties of peptide D-RADA16-RGD respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the surface of these materials. Confocal laser scanning (CLS), cell counting kit-8 tests (CCK-8), alizarin red S staining, cell immunofluorescence analysis and Western blotting were involved in vitro. Also biosafety and bioactivity of them have been evaluated in vivo. RESULTS: Proteinase K and circular dichroism spectroscopy demonstrated that D-RADA16-RGD in nHA/PA66 was able to form stable-sheet secondary structure. SEM and TEM showed that the D-RADA16-RGD material was 7–33 nm in width and 130–600 nm in length, and the interwoven pore size ranged from 40 to 200 nm. CLS suggests that cells in nHA/PA66/D-RADA16-RGD group were linked to adjacent cells with more actin filaments. CCK-8 analysis showed that nHA/PA66/D-RADA16-RGD revealed good biocompatibility. The results of Alizarin-red S staining and Western blotting as well as vivo osteogenesis suggest nHA/PA66/D-RADA16-RGD exhibits better bioactivity. CONCLUSION: This study demonstrates that our nHA/PA66/D-RADA16-RGD composite exhibits reasonable mechanical properties, biocompatibility and bioactivity with promotion of bone formation.
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Actin Cytoskeleton , Blotting, Western , Bone Regeneration , Cell Count , Cell Culture Techniques , Circular Dichroism , Endopeptidase K , Fluorescent Antibody Technique , In Vitro Techniques , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Osteogenesis , Sincalide , Spectrum AnalysisABSTRACT
Objective To investigate the effect of transverse extrapedicular unilateral percutaneous vertebroplasty (PVP) via transverse process in treating the osteoporotic vertebral compression fractures.Methods A retrospective study was performed on 16 patients with osteoporotic vertebral compression fractures of upper lumbar treated from August 2016 through December 2016.There were seven males and nine females,at a mean age of 73.5 years (range,62-90 years).All the patients reported severe back pain,with an average history of 2 weeks (range,1-24 weeks).MRI confirmed the diagnosis of osteoporotic vertebral compression fractures,and the compression degree of the affected vertebral body was (25.4 ± 5.3) ％.All the patients were treated with extrapedicular unilateral PVP via transverse process under local anesthesia.The operation time,fluoroscopy frequency,bone cement injection volume,and bone cement dispersion were recorded.Back pain and function recovery were assessed by visual analogue scale (VAS) and Oswestry disability index (ODI),respectively.Results All patients were followed up for 6-12 months (mean,8 months).All operations were successful without complications.The average operation time was 20 min (range,15-30 minutes),and there were 3-6 times of fluoroscopy with successful incubation.The average volume of bone cement injected to each injured vertebral body was 6.2 ml (range,5-9 m1).The bone cement dispersed satisfactorily in the vertebral body.Complete relief of lumbar and back pain was achieved in 14 patients,and remarkable relief in two patients.The postoperative VAS and ODI at 24 hours,72 hours,and 6 months were significantly lower than those before operation (P ＜0.01).Conclusion Extrapedicular unilateral percutaneous vertebroplasty via transverse process has the advantages of uniform fractured bone cement perfusion,significant pain relief,and rapid recovery,and hence is a simple,safe and effective treatment for osteoporotic vertebral compression fractures of the upper lumbar vertebrae.
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Currently,there is no study on the unified coding of the spinal nerve and its main branches.The positions of spinal nerve were encoded according to the basic anatomical principles from top to bottom,from inside to outside and from front to back,with reference to AO bone classification and somatic artery coding and injury classification system.The segmental coding of spinal nerves was decided by its branches and running characteristics.The spinal nerve injuries were encoded by a combination of numbers and letters.The first number represented the region,the second represented the injured nerve,and the third represented the specific segment of injured nerve.The injuries of spinal nerve were divided into 5 categories according to severity.The first letter indicated the category of injury,and the second indicated the orientation of the injured nerve.The functional score scale of the innervation area was prepared based on the evaluation of motor function,sensory function and the results of neurophysiological examination.This scale was used to classify the neurological injuries,guide the clinical treatment and evaluate the prognostic outcomes.This coding and classification system can clearly and comprehensively describe the location and type of spinal nerve injuries,and it is convenient for the diagnosis of nervous system damage.It also has important reference value for treatment and prognosis evaluation.
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Abstarct:Objective To evaluate mid-term efficacy and complications of Prestige LP cervical disc arthroplasty ( CDA) for treatment of single-level cervical spondylotic myelopathy .Methods Retrospectively analyzed the clinical data of 29 patients who underwent Prestige LP cervical disc arthroplasty from June 2009 to December 2013 and were followed up for 2 to 6 years.Among them, there were 19 males and 10 females, and the average age was (45.4 ±7.6)years old (ranged from 28 to 58 years old).Cardinal symptom of spinal compression occured in 20 cases of them,and nerve root compression occured in the other 9 cases.Clinical symptoms and functional outcomes were evaluated with Japanese Orthopaedic Association(JOA) scores,neck and arm visual analog scale(VAS) scores,and Neck Disability Index(NDI).Oerpation segmental range of motion(ROM) were evaluated with follow-up dynamic X-ray.Displacement,subsidence of the prosthesis,heterotopic ossifi-cation(HO) and other complications were also investigated .Results The 29 patients were followed up for 24 to 66 months,(35.5 ±10.4) months averagely .At the final follow-up,the JOA score,NDI,Neck-VAS and Arm-VAS were (15.62 ±1.12) points,(14.65 ±5.68)%,(1.93 ± 1.10) points,and (0.76 ±0.99) points respectively,which were significant improved compared with (12.03 ±2.23) points,(42.52 ± 16.31)%,(5.00 ±2.22) points,and (4.59 ±3.18) points preoperatively,and the differences were of statistical significance (P<0.05). The opreation segmental ROM was (7.37 ±3.11)°,which was better remained compared with (8.50 ±3.35)°before operation.After the surgery,there were 1 case of forward displacement ,3 cases of backward displacement ,1 case of subsidence of the prosthesis ,3 cases of adja-cent segment degenerations ,and 14 cases of heterotopic ossification .Conclusion The mid-term efficacy and safety of Prestige LP cervical disc arthroplasty is fine .But there is a high incidence of the prosthesis-related complications which may counteract the function of protecting the adjacent segment .Therefore,the indication,operation skills and perioperative period management of cervical disc arthroplasty are impor -tant aspects to avoid the adverse effect .
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Objective To evaluate the clinical outcomes of lumbopelvic fixation of vertically unstable Tile type C pelvic fractures combined with complex sacral fractures.Methods A prospective study was made on 21 cases of vertically unstable type C pelvic fractures combined with complex sacral fractures admitted between May 2014 and December 2015.There were 10 males and 11 females, with a mean age of 35.9 years (range, 14-59 years).Tile classification of pelvic fractures was type C1 in five cases, type C2 in four and type C3 in 12.Denis classification of sacral fractures was zone I in five cases, zone Ⅱ in seven and zone Ⅲ in nine.Twelve cases had neurological deficits.Operation time, intraoperative blood loss, bone healing time, pelvis vertical displacement and postoperative complications were recorded.Vertical displacement and functional outcome were assessed by Matta method and Majeed score respectively.Results All cases were followed up for (12.5±5.4)months (range, 7-26 months).Operation time was (108.0±49.4) min (range, 64-225 min).Intraoperative blood loss was 150-3 000 ml[400(225-500)ml].All fractures were healed at (19.0±4.6) weeks (range, 15-32 weeks).Vertical displacement of the pelvis was (8.76±5.46)mm (2.54-21.80 mm) before operation and (4.20±3.22)mm (0-12.57 mm) after lumbopelvic fixation (P<0.05), showing the reduction distance of-4.45-17.86 mm [4.09(1.74-5.58)mm].According to the Matta method, the results were excellent in 13 cases, good in six, and fair in two, with the excellent and good rate of 90%.Majeed score evaluation at last follow-up was 51-98 points and the results were excellent in nine cases, good in nine, fair in two and poor in one, with the excellent and good rate of 86%.Deep infection occurred in two cases who were cured by debridement and antibiotics, and the internal instruments of the two cases were removed after fracture healing.Screw loosening occurred in five cases with no evidence of screw breakage.Four cases complained of foreign body sensation and discomfort in sacral area due to the prominence of the iliac hardware.Four cases had limited range of motion of the lumbar spine, especially in anterior flexion range, and lumbar range of motion was recovered in three of them after removal of the internal fixator.Conclusion Lumbopelvic fixation can restore vertical stability of the pelvis, but removal of the internal fixator is suggested after fracture healing due to the high rate of screw loosening.
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Objective To analyze treatment strategies for complications following lumbopelvic fixation for unstable sacral fractures.Methods Between May 2014 and December 2015,20 patients diagnosed with unstable sacral fracture were treated by lumbopelvic fixation.They were 9 males and 11 females,with an average age of 35.5 years (range,from 14 to 59 years).According to the Denis classification,5 fractures were type Ⅰ,7 type Ⅱ and 8 type Ⅲ.Complications related to lumbopelvic fixation were recorded and followed up.Results All the patients were followed up for an average of 18 months (range,from 12 to 31 months).All the fractures healed after an average of 19 weeks (range,from 15 to 32 weeks).Early complications included neural injury in 2 cases,incision infection in one and pressure ulcer in 2;late complications included prominence of internal implants in 7 cases,loosening of internal implants in 5,lumbopelvic pain or discomfort in 3,limited motion of lumbar vertebrae in 4,limb discrepancy in 3 and rotation deformity of lower limb in one.Conclusions Complications related to wound and internal implants are common following lumbopelvic fixation for sacral fractures.Careful planning and correct choice of internal fixators are the key to decreasing complications.Internal implants should be removed as soon as a sacral fracture unites to decrease the risk of long-term complications.
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BACKGROUND:Mechano growth factor has the potential to activate muscle satelite cels and promote myogenic cel growth, and has dual roles in maintaining bone mass and repairing bone defects. OBJECTIVE: To explore the mechanism underlying osteogenic differentiation of rabbit bone marrow mesenchymal stem cels promoted by the mechano growth factor. METHODS:The best concentration and time of mechano growth factor to promote osteogenic differentiation of rabbit bone marrow mesenchymal stem cels were detected by MTT. The mRNA and protein expressions of alkaline phosphatase and osteocalcin were detected by qPCR and western blot, respectively. The phosphorylation level of AKT and mTOR were detected by western blot assay. RESULTS AND CONCLUSION:The best concentration and time of mechano growth factor was 45 μg/L and 5 days for promoting the osteogenic differentiation of rabbit bone marrow mesenchymal stem cels. The expressions of alkaline phosphatase and osteocalcin at mRNA and protein levels were highest after 4-hour intervention with 45 μg/L mechano growth factor, and meanwhile, the phosphorylation levels of mTOR and AKT were also highest. These findings indicate that the mechano growth factor can promote the differentiation of rabbit bone marrow mesenchymal stem cels into osteoblastsvia PI3K/AKT pathway, and its best concentration and time are 45 μg/L and 4 hours, respectively.
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We carry out the tutorial system in the standardized training of residents,promote students to grasp the clinical skills and clinical research and thinking,and promote teachers' professional theoretical level and teaching ability.In the orthopedic rotation we define the teaching focus to the trainees of different seniority:for junior trainees,the training of medical records writing and basic clinical skills should be focused,and for senior trainees,the emphasis of training is to improve their clinical capacity of diagnosis and treatment.In teaching,the teaching methods of a combination of Multidisciplinary team (MDT) of bone and soft tissue tumors and problem based learning (PBL) have been actively tried to improve students' learning enthusiasm and initiative,which helps the trainees fully grasp the diagnosis and treatment of certain diseases.
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Objective To investigate the general information such as study motivation, study de-mand, and encountered difficulties of foreign medical postgraduates in China. Methods 45 medical post-graduates in Chongqing Medical University participated in this survey in February 2014. The questionnaire consisted of 19 questions, including study motivation, the reasons to learn in China, language proficiency, study expectation, satisfaction rate, and future career plan. In total, 45 questionnaires were handed out, and 42 (93%) were recovered. Results All respondents (42 persons) had already acquired medical license in their own countries. 45%of them (19 persons) had obtained bachelor’s degree in other university and were attracted by the reputation of Chongqing Medical University. 50% of respondents (21 persons) considered language barrier as the biggest problem in their learning process. 60%(25 persons) were generally satisfied with their postgraduate education in China. And lack of clinical practice opportunity was ranked as the No. 1 reason of dissatisfaction (54%, 23 persons). Conclusion Language barrier as well as lack of clinical practice opportunity is the biggest two problems encountered by foreign medical postgraduates in China. Although Chongqing Medical University has gained a lot of experience in foreign medical postgraduate education, improvements regarding training program and mentor selection should still be made.
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BACKGROUND:The hardened acrylic resin bone cement composite after implantation into human body can resist an intensity of 78-93 MPa. But a large amount of heat energy is released by bone cement during the process of solidification and it wil kil normal cel s, leading to peripheral tissue necrosis. OBJECTIVE:To investigate the characteristics of induced knee joint osteoarthritis after application of acrylic resin bone cement composite as a bone substitute for subchondral bone. METHODS:Thirty male Japanese big ear rabbits were randomly and equal y divided into four experimental groups (A, B, C, D) and a blank control group. After removal of subchondral bone on the right medial tibial plateau, polymethyl methacrylate powder/hydroxyapatite composite materials were implanted in rabbits in the experimental groups A, B, C, and D. Rabbits in the blank control group were only subjected to exposure of periosteum on the left medial tibial plateau. At 3, 6, 9 and 12 weeks after removal of subchondral bone, rabbits in the experimental groups A, B, C and D were sacrificed, and subchondral bone specimens were taken for hematoxylin-eosin staining and matrix metal oproteinase expression analysis. At the same time, interleukin-1βand tumor necrosis factor-ɑ levels in the synovial fluid were determined. RESULTS AND CONCLUSION:Mankin score in the experimental group C was significantly higher than in the blank control group and experimental group A (P<0.05). Mankin score in the experimental group D was significantly higher than in the experimental group B (P<0.05). The gray scale of matrix metal oproteinase-1 was highest in the blank control group, fol owed by experimental groups A, B, C, and the last in the experimental group D (P<0.05). Interleukin-1β and tumor necrosis factor-ɑ levels in the synovial fluid were highest in the experimental group D, fol owed by experimental groups C, B, A and the last in the blank control group (P<0.05). These findings suggest that acrylic resin bone cement composite as a bone substitute for subchondral bone induces knee joint osteoarthritis and leads to increases in matrix metal oproteinase-1 and tumor necrosis factor-ɑ levels in the synovial fluid.
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BACKGROUND:Alogeneic bone marrow stromal stem cel transplantation for treatment of bone diseases is a hot topic. To seek effective methods for prevention of post-transplantation immune rejection is urgent to be solved. OBJECTIVE:To explore the expression of MHC antigen on the surface of bone marrow stromal stem cels after osteogenic inductionin vitro. METHODS:Bone marrow samples were extracted from rabbits to in vitro isolate and culture bone marrow stromal stem cels. Then, the cels were cultured in IMDM medium containing bone morphogenetic protein-2. Flow cytometry was used to analyze the expression of MHC antigen on the osteoblasts differentiated from bone marrow stromal stem cels. RESULTS AND CONCLUSION:There was highly expressed MHC I antigen but no MHCII antigen on the osteoblasts differentiated from bone marrow stromal stem cels. After osteogenic induction, no immune rejection was found. These findings indicate that alogeneic or xenogeneic bone marrow stromal cel transplantation can be used in the treatment of bone defects.
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Objective To evaluate the feasibility and clinical effect of stage Ⅰ posterior vertebral corpectomy filled with titanium mesh cages plus long-segmental instrumentation for treatment of Denis type D and E severe unstable thoracolumbar burst fracture.Methods A retrospectively review was made on 14 patients with Denis type D and E severe unstable thoracolumbar burst fracture,having had posterior vertebral corpectomy,titanium mesh bone grafting and long-segmental pedicle screw fixation.Parameters recorded were operation time,amount of bleeding,bone fusion and reduction,postoperative complications,low back pain,neurological performance,restoration and loss of anterior vertebral height,correction and loss of kyphosis,and intraspinal space occupying lesion.Results Mean operation time was 207.1 min (range,148-306 min) and blood loss was 585 ml (range,300-1,500 ml).Intraoperative fracture reduction was satisfactory.Follow-up ranged from 18 to 54 months (mean,28 months),which showed no complications of infection,screw-rod breakage,loosening or shifting of the internal fixation device,titanium mesh subsidence and pseudarthrosis,and no signs of adjacent segment degeneration.Six months after operation,CT scan showed bony fusion of the bone-implant interface.At the final follow-up,the Denis pain scale improved significantly including 12 patients with completely relieve of pain (P1) and 2 ache slightly but no need of taking painkiller (P2).Neurological functions were improved by 1-3 degree in all patients.Percentage of anterior vertebral height was (41.2 ± 8.9)％ before operation,significantly reduced to (8.3 ± 4.8) ％ one week after operation and to (8.9 ± 5.1) ％ at the final follow-up (P ＜0.01).Mean loss of anterior vertebral height was 0.6％.Sagittal kyphotic angle was (36.9 ± 4.9) °before operation,significantly reduced to (8.1 ± 3.4) ° one week after operation and (8.5 ± 3.8) °at the final follow-up (P ＜0.01).Mean loss of kyphotic angle was 0.9°.Ratio of intraspinal space occupancy was (74.9 ± 11.3) ％ before operation but recovered to (4.1 ± 1.6) ％ one week after operation and (1.8 ± 1.4) ％ at the final follow-up,with significant differences in pair comparison (P ＜ 0.01).Conclusion The use of posterior vertebral corpectomy and fusion with titanium mesh cage fusion in conjunction with long-segment instrumentation are effective for spinal canal decompression,fracture reduction,three-column reconstruction as well as rigid fusion at one stage,lumbar pain relief,neurological function recovery,prevention of correction loss and vertebral height restoration.