Matrix Stiffness Affects Mitochondrial Heterogeneity of Tibial Plateau Chondrocytes in Knee Osteoarthritis / 医用生物力学

Objective To investigate the difference of matrix stiffness in different regions of tibial plateau in osteoarthritis (OA) and its effects on morphology of the cartilage and mitochondria. Methods The tibial plateau cartilage specimens of OA were obtained for nanoindentation test, transmission electron microscopy and histological analysis. The stiffness of cartilage matrix in different regions of OA tibial plateau was detected by nano-indentation. The morphology of cartilage mitochondria in different regions was observed by transmission electron microscopy, and the changes of mitochondrial plane area, shape and ridge volume density were quantitatively analyzed. Cartilage injury in different regions of OA tibial plateau was observed by histological staining. Results The cartilage of OA tibial plateau showed regional heterogeneity, and the cartilage and mitochondria on medial side of varus knee OA were more severe, and the matrix stiffness was higher. The OA scores were positively correlated with matrix stiffness. There was also a significant correlation between OA scores and mitochondrial morphology: the higher OA scores, the larger and rounder mitochondrial plane area, and the lower cristae volume density. Conclusions The differences of tibial plateau revealed the correlation between cartilage matrix stiffness, OA scores and mitochondrial morphological parameters. The increased cartilage matrix stiffness may be the main cause of chondrocyte mitochondrial injury, and further aggravate the progression of OA.

Application of 3D printing models in undergraduate medical imaging teaching / 中华医学教育探索杂志

Objective To evaluate the effect of 3D printing models applied to Medical Imaging Di-agnosis Undergraduate Teaching. Methods Students in the year 2012/2013 of Shanghai Jiao Tong Univer-sity School of Medicine stomatology specialty were chosen for this study, including 38 students in the exper-imental group (2013) and 40 students in the control group (2012). All of them were taught by the same group of teachers, including 28 core curriculum hours and 5 practice class hours. 3D printing technology with PPT was applied to the experimental group in the medical imaging diagnostic teaching, and conventional teaching including PPT and usual models in the control group. Medical students were given a test about cardiovascular system and tasked with completion of drawing hand and foot bones. Students in experimental group were also asked to complete a questionnaire about their experience. Results The questionnaire showed that 3D printing teaching molds with PPT was of great significance to improve the students interest in learning imaging anatomy, to meet the vast majority of students' learning requirements, and to achieve satis-factory results. The average scores of the circulatory system test in the experimental group were higher than that of the control group [(8.32 ±2.352) vs. (6.15 ±1.284), P<0.05)]. Students in experimental group per-formed better than students in the control group on the Locomotor system test [(6.81 ±1.347] vs. (3.84 ± 0.985), P<0.01]. Conclusions 3D printing mold combined with PPT teaching method can promote the med-ical imaging anatomy structure, learning effect and teaching quality, and has practical value in the under-graduate teaching of medical imaging diagnosis.

Automated three-dimensional measurement on anatomic parameters of proximal femur / 医用生物力学

ObjectiveTo automatically measure anatomic parameters of proximal femur by establishing three-dimensional (3D) coordinate system of the femur based on bony landmarks, so as to assist pre-operative planning and design of customized femoral stem. MethodsThe software named "Femeter" was independently developed for anatomic measurement of the femur, which allowed importing the femur models with STL format and manually locating the targeted anatomic landmarks. The 3D modeling of femoral medullary canal was rapidly created by semi-spherical iterative searching algorithm, and 16 key anatomic parameters of proximal femur, including femoral head radius, neck-shaft angle, anterversion were automatically calculated by least-squares fitting algorithm. ResultsBy experimenting on 30 femur STL models, the average execution time of single measurement was (0.95±0.16) seconds, and the intra-class correlation coefficient of 9 anatomic parameters was between 0.907 and 0.999, which showed high intra-rater and inter-rater reliability. ConclusionsThe automatic modeling and execution time of measuring algorithm by Femeter are fast, with satisfactory measurement repeatability and easy interaction, which is easily applicable to clinical practice. The 3D anatomic measurement of proximal femur can provide solid data for pre-operative planning of total hip arthroplasty, selection of commercialized femoral stem and design of customized femoral stem.

CT and MRI manifestations of the axial area primary peripheral primitive neuroectodermal tumors / 中国骨伤

<p><b>OBJECTIVE</b>To explore CT and MRI manifestations of the axial area peripheral primitive neuroectodermal tumors (pPNETs) in order to improve the knowledge of this disease.</p><p><b>METHODS</b>The clinical data of 10 patients with pPNETs underwent pathologically confirmed were retrospectively analyzed from October 2008 to May 2014. There were 7 males and 3 females, aged from 8 to 49 years old with median of 23.6 years. The preoperative multi-slice spiral CT scan was completed in 3 cases, plain CT scan and enhancement in 4 cases; MRI and enhancement scanning in 5 cases; and among them, 2 cases underwent both MRI and CT scan.</p><p><b>RESULTS</b>In-bone type was found 6 cases and out-bone type was found 4 cases. Three cases occurred in sacral vertebrae, 2 cases in lumbar vertebrae, 1 case in cervical vertebrae, 1 case in cervical spinal canal, 1 case in coccyx, 1 case in the right iliac bone, 1 case in presacral space. Cross sectional the smallest tumor maximum level was 1.1 cmx 1.2 cm in size, the biggest tumor was 8.0 cm x 9.2 cm, the median size was 4.4 cm x 5.7 cm, of them, the tumor of maximal diameter larger than 5 cm had 6 cases. Except 2 cases-without destruction of bone, the other 5 cases with osteolytic destruction, 2 cases with calcification, 1 case with mixed. Equidensite was main in CT scan, 1 case with uniform density, other 6 cases with uneven density,in which 3 cases with "floating ice" change; 1 case with moderate strengthening, other 3 cases with obviously strengthening, 2 cases with multiple small blood vessels in enhancement scanning. MRI of 5 cases showed the signal of isointensity on T1WI, the slightly high signal on T2WI and the signal was not uniform; after enhancement scan, the signal of 5 cases obviously enhanced. Two patients complicated with vertebral compression fractures, no periosteal reaction was found in all patients, and no the destruction of intervertebral disk was found in 5 patients of MRI scan.</p><p><b>CONCLUSION</b>The axial area pPNETs is common among children and the youth, and the mass often is huge. The mass of in-bone type often envelopes the vertebral body, and main located on prevertebral space, all associated with bone destruction, osteolytic destruction is common, and primary vertebral bodies also is common, attachment primary or involvement is few found, it can involve the spinal canal and anterior wall of spinal canal is common, some cases complicate with multiple newly born small vessels. The mass of out-hone type in deep soft tissue is common, minority primary spinal canal, many complicated with vertebral bone destruction, osteolytic destruction was main. The intervertebral disk was not invaded and intervertebral space has not stenosis. CT scan offer complicate with "floating ice" sign, and in-bone type is common. Isointensity is main on MRI TlWI and slightly longer signal is main on MRI T2WI, strengthening signal is obvious.</p>

Diagnostic value of 3D-indirect magnetic resonance arthrography in detecting meniscal tears of the knees / 中国骨伤

<p><b>OBJECTIVE</b>To explore the diagnostic value of 3D-indirectmagnetic resonance (MR) arthrography in detecting meniscustears of the knees.</p><p><b>METHODS</b>Form January 2013 to January 2014, routine plain MR of the knees followed by the 3D-indirect MR arthrography was performed in 42 patients with suspected meniscal tears clinically. There were 31 males and 11 females, with an average age of 38.4 years old (ranged, 21 to 67 years old). The duration of the course ranged from 2 h to 15 d. The clinical symptom was knee pain. All the patients got subsequently arthroscopic examination or operation. The sensitivity and specificity of routine plain MR and 3D-indirect MR arthrography were compared based on the results of arthroscopic examination or operation.</p><p><b>RESULTS</b>The signal intensity in the area of meniscal tears on image of 3D-indirect MR arthrography was obviously higher than that of routine plain MR. The sensitivity of 3D-indirect MR arthrography was 85.79% (87/102), while the routine plain MR was 52.94% (54/102), and the specificity improved from 67.78%(61/90) to 86.67%(78/90). The difference was statistically significant (χ2 = 25.90, P < 0.01; χ2 = 9.13, P < 0.01).</p><p><b>CONCLUSION</b>In comparison with the routine plain MR findings, 3D-indirect MR arthrography demonstrates meniscus tears of the knee with the better sensitivity and specificity.</p>

MRI ainalysis of the pseudo-tears of the lateral meniscus of the knee and its clinical significance / 中国骨伤

<p><b>OBJECTIVE</b>To determine the mechanism of pseudo-tears of the lateral meniscus caused by the transverse geniculate ligament (TL) and the miniscofemoral ligament(MFL) and to investigate a method to differentiate pseudo-tears from true tear of the lateral meniscus.</p><p><b>METHODS</b>Form June 2012 to February 2014, MR examinations of 72 knees (44 left knees and 28 right knees) without tear of the lateral meniscus verified by arthroscopy were performed in the sagittal and coronal plane. There were 41 males and 31 females in the group, with an average age of 33.7 years old (ranged from 25 to 61). The MR appearance of the TL and the MFL was carefully observed.</p><p><b>RESULTS</b>There existed fatty tissue in the gap between the TL and the anterior horn of the lateral meniscus and its central tendinous attachment. On the sagittal images, the fatty tissue formed a linear high-signal cleft between the TL and the anterior horn of the lateral meniscus. This might be mistaken as an oblique tear within the anterior horn of the lateral meniscus. It was called as pseudo-tears of the anterior horn of the lateral meniscus. In sagittal plane, the MFL was identified as a circle-like or short stick-like area of low signal intensity anterior or posterior to the posterior cruciateligament. Nevertheless, a belt-shaped area of low signal intensity from the posterior horn of the lateral meniscus to lateral facet of the medial femoral condyle was identified in the coronal plane. A linear area of high signal intensity between the MFL and the lateral meniscus was found in sagittal plane, which might be mistaken as an oblique tear within the posterior horn of the lateral meniscus. It was called pseudo-tears of the posterior horn of the lateral meniscus. The occurrence rate of the TL was 34.7% (25/72). The prevaleribe of pseudo-tears of the anterior horn of the lateral meniscus was 18 cases. The shape of the anterior horn of the lateral meniscus was regular, and the course of the pseudo-tears cleft was oblique. The occurrence rate of the MFL was 73.6% (53/72), which included the anterior MFL 23.6% (17/72), the posterior MFL 70.8% (51/72) and the two ligaments coexisted 16.7% (12/72). The prevalence of pseudo-tears of the posterior horn of the lateral meniscus was 25 cases. All observed pseudo-tears had either in posteroinferiorly oblique direction (19/25) or in vertical direction (6/25).</p><p><b>CONCLUSION</b>Based on the location and direction of pseudo-tears and observation in the continuous sagittal plane and the coronal plane, pseudo-tears is easily differentiated from the true tear of the lateral meniscus</p>

MSCT diagnosis of primary ureteral carcinoma and non-specific ureteritis / 实用放射学杂志

Objective To discuss the MSCT diagnosis and differential diagnosis of primary ureteral carcinoma and non-specific u-reteritis.Methods The pre-contrast and three-phase post-contrast MSCT scans were performed in a group of 12 patients with prima-ry ureteral carcinoma and 5 patients with non-specific ureteritis confirmed by pathology.The MPR,CPR,CTU images were genera-ted from raw data.The MSCT image feature of the primary ureteral carcinoma and non-specific ureteritis were observed respective-ly.Results ①1 2 cases of primary ureteral carcinoma pathologically diagnosed as transitional cell carcinoma,The manifestations of MSCT:9 cases (9/12)showed irregular thickened wall and eccentricity lumen stenosis,5 cases had soft tissue mass in lumen,3 ca-ses (3/12)showed irregular thickened wall and central lumen stenosis.The lesions lumen was significant stenosis,edges and broken ends were irregular.②The non-specific ureteritis manifestations of MSCT:1 case (1/5)showed irregular thickened wall and eccen-trical lumen stenosis;3 cases (3/5)showed irregular thickened wall and central lumen stenosis,and the edge of obstruction was rel-atively smooth.1 case (1/5)prompted hydronephrosis and hydroureter.The lesions lumen was still relatively smooth,had no sig-nificant thickening.③On non-enhanced CT,primary ureteral carcinoma attenuation was equal to the non-specific ureteritis (P>0.05).The degree of enhancement was higher than non-specific ureteritis during all enhanced phases (All P<0.05).Conclusion Main performance characteristics of primary ureteral carcinoma and non-specific ureteritis can both cause the ureteral wall thickening in different appearances and degrees.The MSCT enhanced scan with varies images processing techniques such as MPR,CPR and CTU showed some clinical application potentiality in both diseases diagnosis and discrimination.

Individualized treatment of orthopaedics and 3D printing technology / 医用生物力学

Individualized treatment is an important direction in the development of orthopaedics. Either the application of the custom-made implants or using patient-specific surgical instrument to assist the implantation of conventional prosthesis, theoretically, could improve the matching between the implants and adjacent bony structures, so as to improve the overall function of the patients. However, the superiority of individualized treatment in theory cannot compensate its complexity and time-lag caused by individualized therapy in preoperative planning, design, manufacturing, etc. Therefore, individualized treatment is just a concept in most of the time. With the development of image technology and the maturity of 3D printing technique, the efficiency of individualized design and manufacturing is expected to be improving significantly, which shows the potential to translate this elegant concept into a practical principle.

Research and analysis of failure data of contemporary artificial joint registration system / 生物医学工程学杂志

This paper is aimed to focus on the joint prosthesis failure event, to collect the statistic data about the failure of artificial joints issued by authoritative organizations at home and aboard, and to compare the functions of different types of the artificial joints. We generalized and compared current study analyzing the failure reason and type of joint prosthesis, and categorized the failure events according to the failure occurring time, i. e. short-term, medium-term and long-term. This paper could be helpful for improving and summarizing of artificial joint replacement surgery, and could put forward the requirements for the future artificial joints.

The artificial joint failure types and analysis / 中国医疗器械杂志

This paper focused on the joint prosthesis failure event, through survey and investigation in different kinds of case studies, generalized and analyzed the failure reason of joint prosthesis. The failure reason been categorized according to the failure occurring time: short-term, medium-term and long-term, and for each category, the characteristics and root causes are discussed, and the corresponding countermeasures put forward.

Biomechanical analysis and reasoning on dislocation failure after total hip arthroplasty / 医用生物力学

Objective To propose a detailed method on the diagnosis of dislocation failure by studying the mechanism of mechanical failure and causes of dislocation occurrence after the total hip arthroplasty (THA). Methods The correlation between dislocation failure and clinical situation, product design and patients was analyzed by establishing the dislocation model to study the biomechanical mechanism of dislocation procedure. Results The reasoning route for dislocation analysis after THA was proposed and the visual hip prosthesis motion analysis software was developed and validated. Conclusions Case study on dislocation failure after THA shows that the proposed method and developed software can judge the cause of dislocation incidence in detail, and determine the relationship between implanting position for the hip prosthesis and dislocation incidence. Meanwhile, it can find the best implanting position before operation and analyze the risk of dislocation incidence, which will be helpful for the prosthesis design.

Dislocation risk after total hip arthroplasty / 医用生物力学

Objective To investigate and analyze the risk of dislocation failure after total hip arthroplasty (THA). Methods The optical motion capture system was used to obtain the kinematic data of the lower limbs during actions of daily living (ADLs) from normal people. The visual hip prosthesis motion analysis software was designed and developed to measure the maximum safe motion space of the hip prosthesis with different design parameters and judge the safety of the hip prosthesis by analyzing the relative motion relation between the cup and prosthetic stem. Results Based on the measured kinematics data, the motion analysis software could compare the range of motion of the natural joints and that after THA. Thus, the relationship between the dislocation of hip prosthesis and ADLs was obtained and the dislocation risk after THA was investigated. Conclusions There is a high risk when activities that require a high flexion motion are performed, especially for the kneeling and squatting activity.