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Objective: To correlate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) features to clinical and computed tomography (CT) morphological features of osteoid osteoma (OO).Materials and Methods: Our institutional review board approved this retrospective study, waiving the need for informed consent. We included the 102 patients treated with interstitial laser ablation for histologically documented OO at our institution in 2008-2013. DCE-MRI variables were the time-enhancement pattern and rising slope (Sloperise) and CT variables were the bone and segment involved (OObone and OOsegment, respectively), OO location relative to the native cortex (OOcortex), nidus surface area, vessel sign, and largest neighboring-vessel diameter (Dmaxvessel). Descriptive statistics and correlations linking DCE-MRI findings to clinical and CT characteristics were computed.Results: DCE-MRI showed early arterial peak enhancement in 95 (93%) cases, with a mean Sloperise of 9.30 ± 8.10. CT visualized a vessel sign in 84 (82%) cases with a mean Dmaxvessel of 1.10 ± 0.60 mm. By univariate analysis, Sloperise correlated significantly with pain duration and Dmaxvessel (r = 0.30, P = 0.003; and r = 0.22, P = 0.03; respectively). Analysis of variance showed that Sloperise correlated significantly with OObone (P < 0.001), with a steeper slope for OOs located in short or flat bones.Conclusion: This study suggests more abundant vascularization of OOs with long-lasting pain and location on short or flat bones. [ABSTRACT FROM AUTHOR]

In osteoarthritis, magnetic resonance imaging is the method of choice to image articular cartilage and 'bone marrow lesions.' However, the calcified cartilage, the subchondral bone plate, and trabecular subchondral bone that are mineralized tissues strongly attenuate X-rays and are therefore potentially accessible for analyses using computed tomography (CT). CT images nicely show osseous cardinal signs of advanced osteoarthritis such as osteophytes, subchondral cysts, and subchondral bone sclerosis. But more importantly, CT can help us to better understand the pathophysiology of knee osteoarthritis from the measurement of the density and structure of subchondral mineralized tissues in vivo. For that purpose, we recently developed dedicated image analysis software called Medical Image Analysis Framework (MIAF)-Knee. In this manuscript, our aims are to present current knowledge on CT imaging of the subchondral bone in knee osteoarthritis and to provide a brief introduction to basic technical aspects of MIAF-Knee as well as preliminary results we obtained in patients with knee osteoarthritis as compared to control subjects. [ABSTRACT FROM AUTHOR]

Introduction: In assessing cervical fractures of the proximal femur, this in vitro quantitative computed tomography (QCT) study had three objectives: to compare QCT to dual-energy X-ray absorptiometry (DXA) for predicting the failure load of the proximal femur, to compare the contributions of density and geometry to bone failure load, and to compare the contributions of cortical and trabecular bone to bone failure load. A novel three-dimensional (3D) analysis tool [medical image analysis framework (MIAF-Femur)] was used to analyze QCT scans. Methods: The proximal ends of 28 excised femurs were studied (1) using QCT to separately measure bone mineral density (BMD) and geometric variables of trabecular and cortical bone, (2) using mechanical tests to failure in a stance configuration, and (3) using DXA to measure BMD. The variables were described with mean, standard deviation, and range. Correlation matrix and multivariate linear models were computed. Results: Among correlations, cortical thicknesses of the femoral neck were significantly correlated with femoral failure load, especially of the inferoanterior quadrant (r² = 0.41; p < 0.001), as was cortical volume at the "extended neck" (r² = 0.41; p < 0.001). Femoral failure load variance was best explained by a combination of QCT variables. Combining densitometric and geometric variables measured by QCT explained 76% of femoral failure load variance compared with 69% with the DXA model. Geometric variables (measured by QCT) explained 43% of femoral failure load variance compared with 72% for densitometric variables (measured by QCT). A model including only trabecular variables explained 52% of femoral failure load variance compared with 59% for a model including only cortical variables. Conclusion: The QCT-MIAF reported here provides analysis of both geometric and densitometric variables characterizing cortical and trabecular bone. Confirmation of our results in an independent sample would suggest that QCT may better explain failure load variance for cervical fracture than the gold standard DXA-provided BMD. [ABSTRACT FROM AUTHOR]

In seven of eight patients with osteoporosis circumscripta of the cranial vault, the pagetic bone lacunae were separated from the normal bone by a lucent rim visible on conventional radiographs and computed tomography scans. The contour of the rim was sharp on the side of the healthy surrounding bone and hazy on the side of the defect. To our knowledge, this sign has been reported in one single previous article dealing with two pagetic patients with the bisphosphonate escape phenomenon. [ABSTRACT FROM AUTHOR]

Complications due to vertebroplasty may be divided into two categories whether or not they are related to polymethylmethacrylate (PMMA) cement leakage from the compressed vertebral body. PMMA leakage is a very frequent occurrence in vertebroplasty is also the main source of complications. Neurological complications are due to cement leakage into the spinal canal and less exceptionally into the intervertebral foramen. The transpedicular needle approach reduces the risk of cement leakage into the foramen. Pulmonary embolism of PMMA may occur when there is a failure to recognize venous migration of cement early during the procedure. Cortical destruction, presence of an epidural soft-tissue mass, highly vascularized lesions, and severe vertebral collapse are factors which increase the rate of complications, which is therefore much higher in metastatic than in osteoporotic vertebral collapse. Prevention of PMMA leakage-related complications is a multifactorial issue including procedure preparation, needle approach and placement, and cement application. The technical refinements which may help reduce the risk of PMMA leakage are reviewed in this article. Experimental data have shown that systemic reactions may occur during vertebroplasty in the absence of cement leakage. These reactions may be partly related to vascular embolism of bone marrow fat. Another controversial issue is a possible increase in the risk of vertebral collapse of adjacent vertebrae following vertebroplasty. Prospective randomized studies are needed to resolve this issue. [ABSTRACT FROM AUTHOR]

: In this retrospective study of hip fracture risk evaluation from hip dual-energy X-ray absorptiometry (DXA) scans, our objectives were to determine which part of the femoral neck length contributes most to the fracture risk and to define a geometric parameter better than hip axis length (HAL) for discriminating hip fracture patients. Forty-nine Caucasian women with a nontraumatic femoral neck fracture were matched on age to 49 normal women and on both age and femoral neck bone mineral density (BMD) to 49 unfractured women. In addition to BMD, geometric parameters including neck–shaft angle, neck width and several HAL segments were evaluated by discriminant analysis to determine which was the best hip fracture discriminator. Neck–shaft angle had a limited influence on the hip fracture risk. Age-related bone loss was associated with a neck width increase in unfractured and fractured patients. HAL was significantly longer in fractured patients and was a significant discriminator between fractured patients and normal controls. HAL was not significant as a discriminator between fractured and low-BMD unfractured patients. The intertrochanter–head center distance (from the intertrochanteric line to the femoral head center) coincides with the femoral lever arm and includes no segments that adapt to BMD changes, such as the greater trochanter–intertrochanter distance. Among all tested lengths, this segment was the part of HAL that discriminated best between fractured and low-BMD unfractured patients. A longer intertrochanter–head center distance increased the risk of femoral neck fracture among low-BMD patients. Including automatic measurement of this segment in standard DXA protocols may prove useful in identifying patients at high risk for hip fracture. At present, HAL remains the easier neck length to measure, but automatic evaluation of the intertrochanter–head center distance must be a goal for future image analysis development. [ABSTRACT FROM AUTHOR]

The most serious complication of Paget's disease is sarcomatous degeneration of pagetic bone. Multifocal sarcomatous degeneration occurs mainly in polyostotic Paget's disease. Multifocal Paget's sarcoma is uncommon and can arise in any site. We report two cases of synchronous multifocal sarcomatous degeneration. The two patients were elderly women (aged 77 and 86 years, respectively) who developed sarcomatous lesions concomitantly, in the first case report in left ilium, left tibia, and first lumbar vertebra and in the second case report in the skull, right ilium, and sacrum. Whether these cases are due to the simultaneous development of several primaries or to metastases from a single primary remains unclear. [ABSTRACT FROM AUTHOR]

We present five cases of a distinctive type of longitudinal stress fracture of the upper femoral shaft in which the fracture line is parallel to the outer surface of the bone, in contrast to the perpendicular orientation to the cortical surface in previously reported cases of diaphyseal stress fractures. In two cases the fracture recurred after 15 and 18 months, respectively. [ABSTRACT FROM AUTHOR]

A 69-year-old woman with a 25-year history of recurrent sciatica presented with an expanding lytic lesion of the right side of the first sacral vertebra. Histological examination proved the lesion to be a DF. DF is usually diagnosed in young patients and is very rarely located in the spine and sacrum. The growth rate of the tumor was presumed to be very low because it had not progressed from radiological studies performed 9 years previously. The clinical, radiological, and pathological features of DF are described, and the differential diagnoses are discussed. The most difficult problem is to distinguish DF from a low-grade fibrosarcoma or chordoma. [ABSTRACT FROM AUTHOR]

This report concerns 12 patients, eight young adults and four adolescents, presenting with lumbar or sciatic pain. This was associated with an unusual defect of the inferior and posterior edges of the vertebral bodies of L4 or L5, together with a small bony ridge protruding into the spinal canal. We found 11 similar cases in the literature, all involving adolescents except for one young adult. It has been considered to be the result of a fracture of the posterior ring apophysis in association with a herniated disc. In our cases, in the absence of any known previous trauma, the radiological features and surgical results and the similarity and frequent association with typical lesions of Scheuermann disease, all suggest a posterior marginal cartilaginous node. The inferior lumbar location and frequent association with herniated disc and sciatic nerve root compression in young patients are discussed. [ABSTRACT FROM AUTHOR]