Detection of acute avascular necrosis of the femoral head in dogs: dynamic contrast-enhanced MR imaging vs spin-echo and STIR sequences (original) (raw)
Related papers
Computer-Assisted Image Analysis of the Rat Postosteonecrotic Remodeled Femoral Head
Experimental and Molecular Pathology, 2001
Osteonecrosis of rat femoral heads was induced by stripping the head that could rightfully be applied to experimental exploraperiosteum of the neck and cutting the ligamentum teres. The epiphyseal tion of treatment modalities premised to hinder or halt the marrow and bone were necrotic on the 5th postoperative day. Specimens progression of the disease in man. A review of the literature obtained 18 and 36 days postoperatively showed fibrous and hematopoion avascular osteonecrosis in animals was published recently etic-fatty tissue in the intertrabecular spaces, osteoclastic bone resorption, osteogenesis, and degeneration of the joint cartilage. Morphomet-(Boss and Misselevich, 2001). We examined rat necrotic rically, the means of the height-to-length ratios of the control, 6-day, femoral heads after vascular deprivation induced by strip-18-day, and 36-day femoral heads were 0.26, 0.28, 0.48, and 0.29, ping the periosteum of the neck and cutting the ligamentum respectively. The shape factor of the femoral heads of the control rats teres: Histologically, necrosis of the hematopoietic-fatty was higher than 0.81 in 80% of the cases, while those of rats killed marrow set in on the second postoperative day. Necrosis of on the 6th, 18th, and 36th postoperative day were higher than 0.81 in 65, 60, and 50% of cases, respectively. Statistically, the means of the the subchondral and trabecular bone was apparent on the height-to-length ratios and the values of the shape factors of the femoral fifth postoperative day. First evident during the second postheads of the rats killed 18 days postoperatively differed significantly operative week, sequentially evolving repair processes led from those of the other three groups of rats. The quantitatively gauged to remodeling of the epiphysis and, often, also of the metaphdata of the remodeled epiphyses negate the authors' subjective impression concerning early flattening of the femoral heads after surgically ysis: Granulation tissue invaded the intertrabecular spaces produced osteonecrosis. ᭧ 2001 Elsevier Science from the inflamed joint capsule, macrophages and osteoclasts Key Words: osteonecrosis of the femoral head; Perthes disease; removed the necrotic debris, fibroblasts produced fibrous architectural remodeling of the femoral head; animal model of human tissue, which was repopulated by hematopoietic and fat cells, disease; computer-assisted image analysis. and, eventually, the osteoblasts deposited appositional and intramembranous bone. This remodeling resulted in architectural distortion of the epiphysis and physis, a shift from spongy to near compacta-type bone, and degeneration of the
Lesion size measurement in femoral head necrosis
International Orthopaedics, 2018
Background Management of patients with early stages of osteonecrosis of the femoral head remains controversial. Uniform use of an effective method of evaluation and classification, including both stage and lesion size, would allow for comparison and would significantly improve treatment of patients. There is no consensus on how best to determine lesion size. The purpose of this study was to evaluate and compare accuracy and ease of use of different techniques for determining the size of femoral head lesions. Methods Twenty-five hips with stages I or II osteonecrosis were evaluated with radiographs and MRI. 3-D MRI measurements of lesion size were used as the standard against which to compare visual estimates and angular measurements: necrotic angle of Kerboul, index of necrosis, and adjusted index of necrosis. Results 3-D measurements (necrotic volume) showed regular progression from 2.2 to 59.2% of the femoral head. There was a rough correlation with angular measurements; index of necrosis was closer than the necrotic angle. Visual estimates from serial MRI images were as accurate as angular measurements. Conclusions Simple visual estimates of lesion size from serial MRI images are reasonably accurate and are satisfactory for clinical use. Angular measurements provide some indication of prognosis and treatment; however, they have limited accuracy, with considerable variability between techniques. 3-D MRI volumetric measurements are the most accurate. Using current techniques and software, they are easier to use, requiring similar time and effort to angular measurements. They should be considered for clinical research and publications when the most accurate measurements are required. Keywords Necrotic angle of Kerboul. Index of necrosis. Adjusted index of necrosis. Femoral head. Osteonecrosis. Classification. MRI
Anteversão do colo do fêmur: avaliação clínica versus radiológica
Acta Ortopédica Brasileira, 2005
O objetivo deste trabalho foi o de verificar a correlação entre o ângulo de anteversão femoral medido radiograficamente e os valores das rotações dos quadris apresentados clinicamente. Para isso, foram estudados 64 quadris de 32 pessoas sem nenhuma patologia coxo-femoral prévia, avaliando-se suas rotações com o auxílio de um aparelho específico - o flexímetro - e radiografando os quadris dos pacientes de acordo com o método de Rippstein-Müller. Os resultados obtidos foram analisados estatisticamente, concluindo-se que não houve correlação estatisticamente significante e que, possivelmente, outros fatores, além da anteversão femoral, têm importância na determinação da amplitude das rotações do quadril.
Experimental Model Study of Ischemic Necrosis Induction of the Growing Femoral Head
Acta Ortopédica Brasileira
Many experimental models exist to better understand the necrosis of the femoral head etiology, both in terms of the species variety in which necrosis is induced and in the operative techniques used for treatment. Objective: This study has two main objectives, the first is to review the literature concerning experimental models of avascular necrosis of the growing femoral head, the second, to demonstrate the experimental pig model’s reproducibility using a pilot study. Methods: This was a bibliographic review to describe the attempts over time to find the best species and technique for induction that would reproduce ischemic necrosis of the growing femoral head in humans. Simultaneously, a pilot study was performed to verify the replication of induction in pigs, the species that has more similarities with the human hip. The pilot’s methodological analysis consists of conventional radiology and verification of possible anatomical, pathological changes. Results: In imaging exams; later...
Original paper Imaging of Avascular Necrosis of Femoral Head: Familiar Methods and Newer Trends
2016
Avascular necrosis of the femoral head (AVN) is an increasingly common cause of musculoskeletal disability, and it poses a major diagnostic and therapeutic challenge. Although patients are initially asymptomatic, AVN usually progresses to joint destruction, requiring total hip replacement, usually before the fifth decade. Avascular necrosis is characterized by osseous cell death due to vascular compromise. Avascular necrosis of bone results generally from corticosteroid use, trauma, pancreatitis, alcoholism, radiation, sickle cell disease, infiltrative diseases (e.g. Gaucher’s disease), and Caisson disease. The most commonly affected site is the femoral head and patients usually present with hip and referred knee pain. The aim of diagnostic imaging procedures in avascular femoral head necrosis is to provide the patient with a stage-adapted therapy. Therefore, a differentiated diagnostic work-up is needed. Native radiography of the hip in two planes is still the first step. Over the ...
Imaging of avascular necrosis of bone
European Radiology, 1997
The etiology of avascular necrosis (AVN) is multifactorial. Independent of its etiology and localization it shows typical pathologies and radiological images. In the early stages localized subchondral edema is characteristic. In 50 % of all cases accompanying joint effusion may be found. Due to necrosis of the cells of bone marrow and bone fibrovascular, reactions with hyperemia can be delineated. These reactions allow us to visualize necrosis indirectly. The best imaging methods are MRI and, to a lesser extent, bone scintigraphy. In later stages calcification as well as new bone formation and microfractures are typically demonstrated and visualized best with plain Xrays and CT. Why reparations in many cases, particularly in the hip, are incomplete and may stop in any stage is unknown. Over years clinically complete silent AVNs are not an uncommon finding. Prognosis depends on the localization and size of the AVN. The number of repair mechanisms is best outlined with contrast-enhanced MRI and return of fatty marrow.
Femoral Head Deformation and Repair Following Induction of Ischemic Necrosis
The Journal of Bone and Joint Surgery-American Volume, 2009
Background: Ischemic necrosis of the femoral head can be induced surgically in the piglet. We used this model to assess femoral head deformation and repair in vivo by sequential magnetic resonance imaging and by correlating endstage findings with histologic assessments. Methods: Ischemic necrosis of the femoral head was induced in ten three-week-old piglets by tying a silk ligature around the base of the femoral neck (intracapsular) and cutting the ligamentum teres. We used magnetic resonance imaging with the piglets under general anesthesia to study the hips at forty-eight hours and at one, two, four, and eight weeks. Measurements on magnetic resonance images in the midcoronal plane of the involved and control sides at each time documented the femoral head height, femoral head width, superior surface cartilage height, and femoral neck-shaft angle. Histologic assessments were done at the time of killing. Results: Complete ischemia of the femoral head was identified in all involved femora by magnetic resonance imaging at forty-eight hours. Revascularization began at the periphery of the femoral head as early as one week and was underway in all by two weeks. At eight weeks, magnetic resonance imaging and histologic analysis showed deformation of the femoral head and variable tissue deposition. Tissue responses included (1) vascularized fibroblastic ingrowth with tissue resorption and cartilage, intramembranous bone, and mixed fibro-osseous or fibro-cartilaginous tissue synthesis and (2) resumption of endochondral bone growth. At eight weeks, the mean femoral head measurements (and standard error of the mean) for the control compared with the ligated femora were 10.4 ± 0.4 and 4.8 ± 0.4 mm, respectively, for height; 26.7 ± 0.8 and 31.2 ± 0.8 mm for diameter; 1.1 ± 0.1 and 2.3 ± 0.1 mm for cartilage thickness; and 151°± 2°and 135°± 2°for the femoral neck-shaft angle. Repeated-measures mixed-model analysis of variance revealed highly significant effects of ligation in each parameter (p < 0.0001). Conclusions: Magnetic resonance imaging allows for the assessment of individual hips at sequential time periods to follow deformation and repair. There was a variable tissue response, and histologic assessment at the time of killing was shown to correlate with the evolving and varying magnetic resonance imaging signal intensities. Femoral head height on the ischemic side from one week onward was always less than the initial control value and continually decreased with time, indicating collapse as well as slowed growth. Increased femoral head width occurred relatively late (four to eight weeks), indicating cartilage model overgrowth concentrated at the periphery. Clinical Relevance: Femoral head deformation and internal tissue deposition patterns can be followed accurately in vivo by magnetic resonance imaging. I ntracapsular surgical ligation at the base of the femoral neck and sectioning of the ligamentum teres is an excellent model for inducing ischemia and necrosis in the immature piglet femoral head 1-4. While the development of femoral head deformity is a well-recognized finding with necrosis, the contributions of collapse, slowed growth, and asymmetric
International Journal of Experimental Pathology, 2002
The blood supply of rats 0 femoral heads was severed by cutting the ligamentum teres and stripping the periostium. Histologically, necrosis of the marrow was apparent on the 2nd postoperative day, necrosis of the bone on the 5th postoperative day and fibrous ingrowth on the 7th postoperative day. During the following 5 weeks, progressive resorption of the intertrabecular necrotic debris and necrotic bony trabeculae and subchondral bone plate and, concurrently, appositional and intramembranous new bone formation resulted in remodeling of the femoral heads. In 2 of 7 femoral heads, replacement of the necrotic bone by viable bone was complete at the 42-day postoperative interval. Also, the articular cartilage of the deformed and flattened femoral heads was undergoing degenerative changes. Reduplicating the pathogenically inferred clinical settings of blood supply deprivation, it is proposed that this model, in a small laboratory animal, satisfies the requirements sought for preclinical studies of treatment modalities of avascular osteonecrosis in man.
Avascular Necrosis of the Femoral Head in Dogs - Retrospective Study
Acta Scientiae Veterinariae, 2018
Background: The avascular necrosis of the femoral head is a development disease caused by ischemic necrosis, which is mainly observed in young dogs. The etiology of the disease remains controversial. The diagnosis requires imaging exams such as MRI and radiographs. Thus, the aim of the current study was to retrospectively assess a population of dogs with avascular necrosis of the femoral head in order to feature the disease, as well as to analyze the radiographic appearance of the lesion at the moment of patient consultation.Materials, Methods & Results: The signalment factors of dogs (breed, gender, age and body mass), the affected hind limb, the radiographic appearance of the lesion, the clinical signs at the moment of patient consultation, the time of occurrence and the type of treatment were evaluated. The disease was radiographically classified according to the previously described items. Forty-three cases of avascular necrosis of the femoral head were identified, 97.67% presen...