About two-thirds of those with Alzheimer’s disease (AD) are women, most of whom are post-menopaus... more About two-thirds of those with Alzheimer’s disease (AD) are women, most of whom are post-menopausal. Menopause accelerates the risk for dementia by increasing the risk for metabolic, cardiovascular, and cerebrovascular diseases. Mid-life metabolic disease (e.g. obesity, diabetes, or prediabetes) is a well-known risk factor for dementia. A high fat diet can lead to poor metabolic health in both humans and rodents. The goal of this study was to determine the effects of menopause and high fat diet on metabolic outcomes in the AppNL-Fknock-in mouse model of Alzheimer’s disease. To model menopause, we used an accelerated ovarian failure model (4-vinylcyclohexene diepoxide, VCD). This ovary-intact model is more clinically relevant than an ovariectomy model, as mice go through a perimenopausal period. At 3 months of age, AppNL-Fmice were administered VCD or vehicle (oil) and then placed on either a control diet (10% fat) or a high fat diet (HF; 60% fat) and maintained on the diets until 10...
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
We measured the deformation of the dura and brain surfaces between the time of imaging and the st... more We measured the deformation of the dura and brain surfaces between the time of imaging and the start of surgical resection for 21 patients. All patients underwent intraoperative functional mapping, allowing us to measure brain surface motion at two times that were separated by nearly an hour after opening the dura but before resection. The positions of the dura and brain surfaces were recorded and transformed to the coordinate space of a preoperative MR image using the Acustar neurosurgical navigation system. The mean displacements of the dura and the first and second brain surfaces were 1.2, 4.4, and 5.6 mm, respective/y, with corresponding mean volume reductions under the craniotomy of 6, 22, and 29 ml. The maximum displacement was greater than 10 mm in approximately one-third of the patients for the first brain surface measurement and one-half of the patients for the second. In all cases the direction of brain shift corresponds to a "sinking" of the brain intraoperatively, compared with its preoperative position. We observed two patterns of the brain surface deformation field depending on the inclination of the craniotomy with respect to gravity. Separate measurements of brain deformation within the closed cranium caused by changes in patient head orientation with respect to gravity suggested that less than l mm of the brain shift recorded intraoperatively could have resulted from the change in patient orientation between the time of imaging and the time of surgery. These results suggest that intraoperative brain deformation is an important source of error that needs to be considered when using neurosurgical navigation systems.
Registration of medical images to each other and to physical space for the purposes of surgical p... more Registration of medical images to each other and to physical space for the purposes of surgical planning and surgical navigation can be accomplished using externally attached fiducial markers. The accuracy of fiducial localization, that is, the accuracy of estimating the position of the marker's centroid, is extremely important because marker- based registration accuracy is proportional to localization accuracy. The traditional method of calculating the marker centroid using intensity weighting contains a serious logic flaw. This paper introduces a novel and efficient method for correcting this flaw. Theoretical analysis, computer simulation, and analysis of clinical images demonstrate the importance of this correction.
To propose a new fracture classification according to the direction of epiphysis displacement and... more To propose a new fracture classification according to the direction of epiphysis displacement and to compare clinical findings and surgical outcomes between these subtypes. Retrospective study SETTING:: A tertiary referral hospital PATIENTS/PARTICIPANTS:: Twelve adolescents (mean age 13.4 ± 1.3 years) who experienced separation of the distal ulnar physis were identified from the pediatric trauma database. Closed reduction was attempted for all injuries. If a satisfactory alignment could not be achieved, an open reduction was performed. The clinical outcome was evaluated with Mikic's criteria (union, alignment, length, distal radioulnar joint [DRUJ] subluxation, limitations of elbow/wrist function, and degree of supination/pronation). The impacts of fracture patterns and locations of wrist abrasions on treatment decisions and clinical outcomes were tested with Fisher's exact tests (unadjusted) and logistic regression analyses (adjusted for age and gender) with the bootstrap method. Five orthopedic surgeons used the new classification and the reproducibility was tested with multi-rater kappa. The injury patterns included 6 dorsally-tilted distal ulnas (type I) and 6 volarly-tilted distal ulnas (type II-A [n=1], type II-B [n=3], and type II-C [n=2]). All type I fractures were successfully treated with closed reduction. Five of six cases with type II injuries failed closed reduction due to entrapment of the extensor carpi ulnaris tendon in the fracture site. Eleven of the patients' outcomes were excellent. One patient with a type II-C injury experienced ulnar growth arrest. The multi-rater kappa for the new classification equals to .94, and the p-value is less than .001. The majority of volar-flexion injuries require surgery to reduce the entrapped soft tissue. This new classification is easy to understand with a good inter-rater reproducibility. It is useful in identifying the injury mechanism and correlated with the likelihood of open reduction. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
An image processing technique is presented here for finding centroids of cylindrical fiducial mar... more An image processing technique is presented here for finding centroids of cylindrical fiducial markers attached externally to the human head in CT and MR volume images. The centroids can be used for image registration. The technique, which is fast, automatic, and knowledge-based, has two major steps. First, it searches the whole image volume to find all markerlike objects and gets a position inside each object. We call this position a 'seed' point, and we call the object a candidate marker. Second, it selects the voxels surrounding the seed voxel as marker or non-marker voxels using knowledge-based rules and provides an intensity weighted centroid for each true marker. We call this final centroid the 'fiducial' point of the marker. The technique has been developed on forty-two scans of six patients -- one CT and six MR scans per patient. There were four markers attached to each patient for a total of 168 marker images. On these images the technique exhibits no false positives or false negatives for CT. For MR the false positive rate and the false negative rate are both 1.4%. To evaluate the accuracy of the fiducial points MR-CT registration was performed using geometrical correction for the MR images. The fiducial registration accuracies averaged 0.4 mm and were better that 0.6 mm on each of the eighteen image pairs.
There is an increasing demand for accurate registration of CT and MR images for diagnosis and for... more There is an increasing demand for accurate registration of CT and MR images for diagnosis and for surgical planning. One useful technique registers images using externally attached fiducial markers. Previous studies have shown that point-based registration accuracy depends on fiducial localization accuracy, that is, the accuracy with which the position of a marker centroid can be estimated. This paper investigates the dependence of localization accuracy on marker size. The investigation is based on computer simulations. Three shapes are evaluated-- a sphere, a cylinder, and a cube, each with similar dimensions. The results indicate that (1) the accuracy depends strongly on the ratio of marker size to voxel size and (2) the dependence is almost identical among the three shapes tested. The simulation results are shown to agree with results from clinical images.
ABSTRACT All retrospective image registration methods have attached to them some intrinsic estima... more ABSTRACT All retrospective image registration methods have attached to them some intrinsic estimate of registration error. However, this estimate of accuracy may not always be a good indicator of the distance between actual and estimated positions of targets within the cranial cavity. This paper describes a project whose principal goal is to use a prospective method based on fiducial markers as a 'gold standard' to perform an objective, blinded evaluation of the accuracy of several retrospective image-to-image registration techniques. Image volumes of three modalities -- CT, MR, and PET -- were taken of patients undergoing neurosurgery at Vanderbilt University Medical Center. These volumes had all traces of the fiducial markers removed, and were provided to project collaborators outside Vanderbilt, who then performed retrospective registrations on the volumes, calculating transformations from CT to MR and/or from PET to MR, and communicated their transformations to Vanderbilt where the accuracy of each registration was evaluated. In this evaluation the accuracy is measured at multiple 'regions of interest,' i.e. areas in the brain which would commonly be areas of neurological interest. A region is defined in the MR image and its centroid C is determined. Then the prospective registration is used to obtain the corresponding point C' in CT or PET. To this point the retrospective registration is then applied, producing C' in MR. Statistics are gathered on the target registration error (TRE), which is the disparity between the original point C and its corresponding point C'. A second goal of the project is to evaluate the importance of correcting geometrical distortion in MR images, by comparing the retrospective TRE in the rectified images, i.e., those which have had the distortion correction applied, with that of the same images before rectification. This paper presents preliminary results of this study along with a brief description of each registration technique and an estimate of both preparation and execution time needed to perform the registration .
Twenty-three cases of tuberculous osteomyelitis in children were reviewed. Age at diagnosis range... more Twenty-three cases of tuberculous osteomyelitis in children were reviewed. Age at diagnosis ranged from 10 months to 11 years; 17 patients were younger than 3 years. At clinical presentation, patients were generally afebrile with local swelling and painful limb disability. Delay in diagnosis was common, with an average of 4.3 months. Laboratory data showed mild increase in white cell counts and erythrocyte sedimentation rates. However, C-reactive protein levels were all within normal limits except one. Roentgenograms demonstrated osteolytic lesions over metaphyseal areas with surrounding soft-tissue swelling. All patients had received BCG vaccinations at infancy. None of the patients had pulmonary tuberculosis. No familial or environmental history could be attributed to these victims, nor was any immunodeficient disease noted. Bacille Calmette-Guérin (BCG) vaccination was suspected to be the cause of tuberculosis in these young children. All patients received surgical debridement and oral antituberculosis chemotherapy for 1 year. After an average follow-up period of 71.4 months, all children had complete bony healing and excellent clinical results.
Formosan Journal of Musculoskeletal Disorders, Nov 1, 2011
Dislocation of the patella is not a common disorder of the knee joint and is seen most frequently... more Dislocation of the patella is not a common disorder of the knee joint and is seen most frequently in the adolescent population. Osteochondral fractures account for approximately 5-74% of all acute patellar dislocations and are easy to overlook. The mechanism of injury and presentations of fractured fragments were seldom well describe in published studies. The case reported here is that of a 17-year-old baseball player who suffered an acute patellar dislocation with a large osteochondral fragment fracture, where the fragment presented over the lateral supracondylar aspect of the distal femur. Open reduction and fixation with Kirschner wires gave a good result. Osteochondral fracture of patella is usually regarded as a dislocation phenomenon. However, we review and discuss here three injury mechanisms, and suggest the possible mechanisms by which patellar relocation could have caused our patient's injury and the rare occurrence of a laterally displaced osteochondral fragment over the distal femur.
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright
Analytic solutions to the radiation-hydrodynamic equations are useful for verifying any large-sca... more Analytic solutions to the radiation-hydrodynamic equations are useful for verifying any large-scale numerical simulation software that solves the same set of equations. The one-dimensional, spherically symmetric Coggeshall #9 and #11 analytic solutions, cell-averaged over a uniform-grid have been developed to analyze the corresponding solutions from the Los Alamos National Laboratory Eulerian Applications Project radiation-hydrodynamics code xRAGE. These Coggeshall solutions have been shown to be independent of heat conduction, providing a unique opportunity for comparison with xRAGE solutions with and without the heat conduction module. Solution convergence was analyzed based on radial step size. Since no shocks are involved in either problem and the solutions are smooth, secondorder convergence was expected for both cases. The global L1 errors were used to estimate the convergence rates with and without the heat conduction module implemented.
Formosan Journal of Musculoskeletal Disorders, Aug 1, 2014
Intraosseous lipomas are rare benign primary tumors of the bone. The intraosseous lipoma may be a... more Intraosseous lipomas are rare benign primary tumors of the bone. The intraosseous lipoma may be asymptomatic, and then the lesion may be found incidentally during radiological investigation following an injury in the same region. Intraosseous lipoma is frequently confused histologically or radiologically with fibrous dysplasia, enchondroma, osteoblastoma, chondrosarcoma, bone cyst, and bone infarct. We report a 64-year-old woman suffered from exacerbation of climbing-stairs pain in her right knee due to a juxta-articular bone tumor in distal femur. The symptoms improved after excisional curettage of the tumor and then reconstructed with constrained condylar knee replacement. Histopathological examination of the tumor confirmed the diagnosis of intraosseous lipoma. Although intraosseous lipomas are considered benign lesions and are treated conservatively due to their propensity for spontaneous involution, curettage and grafting has been suggested in cases with painful tumors, pathological fractures or other secondary changes. Curettage and bone grafting is an option for treatment with a good clinical and functional result. And intraosseous lipoma should be considered in the differential diagnosis of osteoblastic lesions for the orthopedic surgeon.
Exostosis, also known as osteochondroma, results from a disorder of the growthplate in which bone... more Exostosis, also known as osteochondroma, results from a disorder of the growthplate in which bone grows from the growth axis to form an irregular projection. This abnormality most commonly occurs around the femur, scapula, humerus, and ribs. Hemothorax and diaphragmatic rupture are known complications of exostotic growth, but they are rarely reported. Here we present a case, possibly the first one in Taiwan, with pin-like inward-facing exostosis in a 20-year-old man with hereditary multiple exostosis that caused hemothorax and required surgical intervention. Exostosis is asymptomatic in most cases and requires no treatment. However, when it causes bursitis or local entrapment of vessels, or when tendons or nerves are involved, surgical resection becomes necessary.
About two-thirds of those with Alzheimer’s disease (AD) are women, most of whom are post-menopaus... more About two-thirds of those with Alzheimer’s disease (AD) are women, most of whom are post-menopausal. Menopause accelerates the risk for dementia by increasing the risk for metabolic, cardiovascular, and cerebrovascular diseases. Mid-life metabolic disease (e.g. obesity, diabetes, or prediabetes) is a well-known risk factor for dementia. A high fat diet can lead to poor metabolic health in both humans and rodents. The goal of this study was to determine the effects of menopause and high fat diet on metabolic outcomes in the AppNL-Fknock-in mouse model of Alzheimer’s disease. To model menopause, we used an accelerated ovarian failure model (4-vinylcyclohexene diepoxide, VCD). This ovary-intact model is more clinically relevant than an ovariectomy model, as mice go through a perimenopausal period. At 3 months of age, AppNL-Fmice were administered VCD or vehicle (oil) and then placed on either a control diet (10% fat) or a high fat diet (HF; 60% fat) and maintained on the diets until 10...
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
We measured the deformation of the dura and brain surfaces between the time of imaging and the st... more We measured the deformation of the dura and brain surfaces between the time of imaging and the start of surgical resection for 21 patients. All patients underwent intraoperative functional mapping, allowing us to measure brain surface motion at two times that were separated by nearly an hour after opening the dura but before resection. The positions of the dura and brain surfaces were recorded and transformed to the coordinate space of a preoperative MR image using the Acustar neurosurgical navigation system. The mean displacements of the dura and the first and second brain surfaces were 1.2, 4.4, and 5.6 mm, respective/y, with corresponding mean volume reductions under the craniotomy of 6, 22, and 29 ml. The maximum displacement was greater than 10 mm in approximately one-third of the patients for the first brain surface measurement and one-half of the patients for the second. In all cases the direction of brain shift corresponds to a "sinking" of the brain intraoperatively, compared with its preoperative position. We observed two patterns of the brain surface deformation field depending on the inclination of the craniotomy with respect to gravity. Separate measurements of brain deformation within the closed cranium caused by changes in patient head orientation with respect to gravity suggested that less than l mm of the brain shift recorded intraoperatively could have resulted from the change in patient orientation between the time of imaging and the time of surgery. These results suggest that intraoperative brain deformation is an important source of error that needs to be considered when using neurosurgical navigation systems.
Registration of medical images to each other and to physical space for the purposes of surgical p... more Registration of medical images to each other and to physical space for the purposes of surgical planning and surgical navigation can be accomplished using externally attached fiducial markers. The accuracy of fiducial localization, that is, the accuracy of estimating the position of the marker's centroid, is extremely important because marker- based registration accuracy is proportional to localization accuracy. The traditional method of calculating the marker centroid using intensity weighting contains a serious logic flaw. This paper introduces a novel and efficient method for correcting this flaw. Theoretical analysis, computer simulation, and analysis of clinical images demonstrate the importance of this correction.
To propose a new fracture classification according to the direction of epiphysis displacement and... more To propose a new fracture classification according to the direction of epiphysis displacement and to compare clinical findings and surgical outcomes between these subtypes. Retrospective study SETTING:: A tertiary referral hospital PATIENTS/PARTICIPANTS:: Twelve adolescents (mean age 13.4 ± 1.3 years) who experienced separation of the distal ulnar physis were identified from the pediatric trauma database. Closed reduction was attempted for all injuries. If a satisfactory alignment could not be achieved, an open reduction was performed. The clinical outcome was evaluated with Mikic's criteria (union, alignment, length, distal radioulnar joint [DRUJ] subluxation, limitations of elbow/wrist function, and degree of supination/pronation). The impacts of fracture patterns and locations of wrist abrasions on treatment decisions and clinical outcomes were tested with Fisher's exact tests (unadjusted) and logistic regression analyses (adjusted for age and gender) with the bootstrap method. Five orthopedic surgeons used the new classification and the reproducibility was tested with multi-rater kappa. The injury patterns included 6 dorsally-tilted distal ulnas (type I) and 6 volarly-tilted distal ulnas (type II-A [n=1], type II-B [n=3], and type II-C [n=2]). All type I fractures were successfully treated with closed reduction. Five of six cases with type II injuries failed closed reduction due to entrapment of the extensor carpi ulnaris tendon in the fracture site. Eleven of the patients' outcomes were excellent. One patient with a type II-C injury experienced ulnar growth arrest. The multi-rater kappa for the new classification equals to .94, and the p-value is less than .001. The majority of volar-flexion injuries require surgery to reduce the entrapped soft tissue. This new classification is easy to understand with a good inter-rater reproducibility. It is useful in identifying the injury mechanism and correlated with the likelihood of open reduction. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
An image processing technique is presented here for finding centroids of cylindrical fiducial mar... more An image processing technique is presented here for finding centroids of cylindrical fiducial markers attached externally to the human head in CT and MR volume images. The centroids can be used for image registration. The technique, which is fast, automatic, and knowledge-based, has two major steps. First, it searches the whole image volume to find all markerlike objects and gets a position inside each object. We call this position a 'seed' point, and we call the object a candidate marker. Second, it selects the voxels surrounding the seed voxel as marker or non-marker voxels using knowledge-based rules and provides an intensity weighted centroid for each true marker. We call this final centroid the 'fiducial' point of the marker. The technique has been developed on forty-two scans of six patients -- one CT and six MR scans per patient. There were four markers attached to each patient for a total of 168 marker images. On these images the technique exhibits no false positives or false negatives for CT. For MR the false positive rate and the false negative rate are both 1.4%. To evaluate the accuracy of the fiducial points MR-CT registration was performed using geometrical correction for the MR images. The fiducial registration accuracies averaged 0.4 mm and were better that 0.6 mm on each of the eighteen image pairs.
There is an increasing demand for accurate registration of CT and MR images for diagnosis and for... more There is an increasing demand for accurate registration of CT and MR images for diagnosis and for surgical planning. One useful technique registers images using externally attached fiducial markers. Previous studies have shown that point-based registration accuracy depends on fiducial localization accuracy, that is, the accuracy with which the position of a marker centroid can be estimated. This paper investigates the dependence of localization accuracy on marker size. The investigation is based on computer simulations. Three shapes are evaluated-- a sphere, a cylinder, and a cube, each with similar dimensions. The results indicate that (1) the accuracy depends strongly on the ratio of marker size to voxel size and (2) the dependence is almost identical among the three shapes tested. The simulation results are shown to agree with results from clinical images.
ABSTRACT All retrospective image registration methods have attached to them some intrinsic estima... more ABSTRACT All retrospective image registration methods have attached to them some intrinsic estimate of registration error. However, this estimate of accuracy may not always be a good indicator of the distance between actual and estimated positions of targets within the cranial cavity. This paper describes a project whose principal goal is to use a prospective method based on fiducial markers as a 'gold standard' to perform an objective, blinded evaluation of the accuracy of several retrospective image-to-image registration techniques. Image volumes of three modalities -- CT, MR, and PET -- were taken of patients undergoing neurosurgery at Vanderbilt University Medical Center. These volumes had all traces of the fiducial markers removed, and were provided to project collaborators outside Vanderbilt, who then performed retrospective registrations on the volumes, calculating transformations from CT to MR and/or from PET to MR, and communicated their transformations to Vanderbilt where the accuracy of each registration was evaluated. In this evaluation the accuracy is measured at multiple 'regions of interest,' i.e. areas in the brain which would commonly be areas of neurological interest. A region is defined in the MR image and its centroid C is determined. Then the prospective registration is used to obtain the corresponding point C' in CT or PET. To this point the retrospective registration is then applied, producing C' in MR. Statistics are gathered on the target registration error (TRE), which is the disparity between the original point C and its corresponding point C'. A second goal of the project is to evaluate the importance of correcting geometrical distortion in MR images, by comparing the retrospective TRE in the rectified images, i.e., those which have had the distortion correction applied, with that of the same images before rectification. This paper presents preliminary results of this study along with a brief description of each registration technique and an estimate of both preparation and execution time needed to perform the registration .
Twenty-three cases of tuberculous osteomyelitis in children were reviewed. Age at diagnosis range... more Twenty-three cases of tuberculous osteomyelitis in children were reviewed. Age at diagnosis ranged from 10 months to 11 years; 17 patients were younger than 3 years. At clinical presentation, patients were generally afebrile with local swelling and painful limb disability. Delay in diagnosis was common, with an average of 4.3 months. Laboratory data showed mild increase in white cell counts and erythrocyte sedimentation rates. However, C-reactive protein levels were all within normal limits except one. Roentgenograms demonstrated osteolytic lesions over metaphyseal areas with surrounding soft-tissue swelling. All patients had received BCG vaccinations at infancy. None of the patients had pulmonary tuberculosis. No familial or environmental history could be attributed to these victims, nor was any immunodeficient disease noted. Bacille Calmette-Guérin (BCG) vaccination was suspected to be the cause of tuberculosis in these young children. All patients received surgical debridement and oral antituberculosis chemotherapy for 1 year. After an average follow-up period of 71.4 months, all children had complete bony healing and excellent clinical results.
Formosan Journal of Musculoskeletal Disorders, Nov 1, 2011
Dislocation of the patella is not a common disorder of the knee joint and is seen most frequently... more Dislocation of the patella is not a common disorder of the knee joint and is seen most frequently in the adolescent population. Osteochondral fractures account for approximately 5-74% of all acute patellar dislocations and are easy to overlook. The mechanism of injury and presentations of fractured fragments were seldom well describe in published studies. The case reported here is that of a 17-year-old baseball player who suffered an acute patellar dislocation with a large osteochondral fragment fracture, where the fragment presented over the lateral supracondylar aspect of the distal femur. Open reduction and fixation with Kirschner wires gave a good result. Osteochondral fracture of patella is usually regarded as a dislocation phenomenon. However, we review and discuss here three injury mechanisms, and suggest the possible mechanisms by which patellar relocation could have caused our patient's injury and the rare occurrence of a laterally displaced osteochondral fragment over the distal femur.
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright
Analytic solutions to the radiation-hydrodynamic equations are useful for verifying any large-sca... more Analytic solutions to the radiation-hydrodynamic equations are useful for verifying any large-scale numerical simulation software that solves the same set of equations. The one-dimensional, spherically symmetric Coggeshall #9 and #11 analytic solutions, cell-averaged over a uniform-grid have been developed to analyze the corresponding solutions from the Los Alamos National Laboratory Eulerian Applications Project radiation-hydrodynamics code xRAGE. These Coggeshall solutions have been shown to be independent of heat conduction, providing a unique opportunity for comparison with xRAGE solutions with and without the heat conduction module. Solution convergence was analyzed based on radial step size. Since no shocks are involved in either problem and the solutions are smooth, secondorder convergence was expected for both cases. The global L1 errors were used to estimate the convergence rates with and without the heat conduction module implemented.
Formosan Journal of Musculoskeletal Disorders, Aug 1, 2014
Intraosseous lipomas are rare benign primary tumors of the bone. The intraosseous lipoma may be a... more Intraosseous lipomas are rare benign primary tumors of the bone. The intraosseous lipoma may be asymptomatic, and then the lesion may be found incidentally during radiological investigation following an injury in the same region. Intraosseous lipoma is frequently confused histologically or radiologically with fibrous dysplasia, enchondroma, osteoblastoma, chondrosarcoma, bone cyst, and bone infarct. We report a 64-year-old woman suffered from exacerbation of climbing-stairs pain in her right knee due to a juxta-articular bone tumor in distal femur. The symptoms improved after excisional curettage of the tumor and then reconstructed with constrained condylar knee replacement. Histopathological examination of the tumor confirmed the diagnosis of intraosseous lipoma. Although intraosseous lipomas are considered benign lesions and are treated conservatively due to their propensity for spontaneous involution, curettage and grafting has been suggested in cases with painful tumors, pathological fractures or other secondary changes. Curettage and bone grafting is an option for treatment with a good clinical and functional result. And intraosseous lipoma should be considered in the differential diagnosis of osteoblastic lesions for the orthopedic surgeon.
Exostosis, also known as osteochondroma, results from a disorder of the growthplate in which bone... more Exostosis, also known as osteochondroma, results from a disorder of the growthplate in which bone grows from the growth axis to form an irregular projection. This abnormality most commonly occurs around the femur, scapula, humerus, and ribs. Hemothorax and diaphragmatic rupture are known complications of exostotic growth, but they are rarely reported. Here we present a case, possibly the first one in Taiwan, with pin-like inward-facing exostosis in a 20-year-old man with hereditary multiple exostosis that caused hemothorax and required surgical intervention. Exostosis is asymptomatic in most cases and requires no treatment. However, when it causes bursitis or local entrapment of vessels, or when tendons or nerves are involved, surgical resection becomes necessary.
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