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1.
Orthopade ; 40(10): 902-6, 2011 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-21922269

RESUMEN

BACKGROUND: Isolated osteoarthritis of the patellofemoral joint occurs in 9% of patients over 40 years of age and women are more often affected. Options of treatment are varied and not sufficiently justified by the literature. MATERIALS AND METHODS: A literature research with keywords in the field of femoropatellar osteoarthritis was carried out in the relevant databases. Studies were categorized into different treatment options and analyzed. RESULTS: There are almost no level I studies comparing the different treatment options. In the literature there are indications that relief of pain can be achieved by conservative treatment, arthroscopic surgery, cartilage conserving surgery and isolated arthroplasty. CONCLUSION: In view of the fact that there are almost no prospective randomized controlled trials, none of the options for treatment can be highly recommended. There is still no gold standard for the treatment of isolated patellofemoral osteoarthritis.


Asunto(s)
Medicina Basada en la Evidencia , Osteoartritis de la Rodilla/cirugía , Articulación Patelofemoral/cirugía , Adulto , Anciano , Artroplastia de Reemplazo de Rodilla , Artroscopía , Cartílago Articular/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/diagnóstico , Dimensión del Dolor , Rótula/cirugía , Estudios Prospectivos , Diseño de Prótesis , Ensayos Clínicos Controlados Aleatorios como Asunto
2.
Spine (Phila Pa 1976) ; 25(23): 3021-5, 2000 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-11145813

RESUMEN

STUDY DESIGN: Bone mineral density and regional blood flow were measured in pigs during long-term methylprednisolone treatment. OBJECTIVES: To investigate possible changes in bone mineral density and vertebral blood flow during long-term glucocorticoid treatment. SUMMARY OF BACKGROUND DATA: Steroid-induced vertebral osteonecrosis preferentially involves endplates and adjacent cancellous bone. The precise etiology of vertebral osteonecrosis during long-term glucocorticoid treatment is unknown. METHODS: Twenty-four 10-week-old female Danish landrace sister pigs from 12 litters were treated in two groups. Twelve animals received oral methylprednisolone for 3 months at a daily dose of 100 mg. The 12 sister pigs received no steroid treatment and served as controls. Regional blood blow was measured by means of microspheres in predefined regions of the C6, T11, and L6 vertebrae. In vitro DEXA scanning of the L2-L4 vertebra was performed to assess bone mineral density. RESULTS: Vertebral cancellous bone and endplate regional blood flow were decreased in the C6 and L6 vertebrae among corticosteroid-treated pigs compared with that of controls.- Width-adjusted lumbar vertebral bone mineral density (g/cm3) was unchanged, whereas projectional lumbar vertebral bone mineral density (g/cm2) was decreased in corticosteroid-treated pigs. CONCLUSIONS: Long-term methylprednisolone treatment decreases vertebral bone blood flow mainly in cancellous bone and endplates. This may be an important factor in the pathogenesis of osteonecrosis secondary to glucocorticoid treatment. Lumbar vertebral bone mineral density was unchanged in growing pigs on long-term glucocorticoid treatment when expressed as volumetric bone density. The effect of glucocorticoid treatment on vertebral bone mineral density appears to depend on whether it is expressed as projectional (g/cm2) or volumetric bone mineral density (g/cm3). Vertebral and longbone growth was reduced during methylprednisolone treatment.


Asunto(s)
Densidad Ósea/efectos de los fármacos , Glucocorticoides/farmacología , Metilprednisolona/farmacología , Columna Vertebral/irrigación sanguínea , Animales , Femenino , Flujo Sanguíneo Regional/efectos de los fármacos , Columna Vertebral/efectos de los fármacos , Porcinos , Factores de Tiempo
3.
J Bone Joint Surg Br ; 85(7): 969-74, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-14516029

RESUMEN

The treatment of osteonecrosis of the femoral head (FHN) is controversial. It mainly occurs in young patients in whom total hip replacement is best avoided because of an increased risk of revision. The objective of this long-term follow-up study was to evaluate the outcome of intertrochanteric flexion osteotomy as a hip joint preserving operation for FHN. Over a 19-year period we carried out 70 intertrochanteric flexion osteotomies for FHN in 64 patients. The mean follow-up was 10.4 years (3.0 to 20.3). The overall mean Harris hip score increased from 51 points preoperatively to 71 points postoperatively. Six patients (9%) developed early postoperative complications. A total of 19 hips (27%) underwent total hip arthroplasty at a mean of 8.7 years after osteotomy. The five-year survival rate was 90%. Survival rates of hips in Ficat stage 2 were higher than those in stages 3 or 4. Hips with a preoperative necrotic angle of <200 degrees had a better survival probability than those with a necrotic angle >200 degrees. Our findings suggest that flexion osteotomy is a safe and effective procedure in Ficat stage 2 and 3 FHN, preferably with a necrotic angle of <200 degrees.


Asunto(s)
Necrosis de la Cabeza Femoral/cirugía , Fémur/cirugía , Osteotomía/métodos , Adolescente , Adulto , Artroplastia de Reemplazo de Cadera , Femenino , Necrosis de la Cabeza Femoral/diagnóstico por imagen , Necrosis de la Cabeza Femoral/etiología , Estudios de Seguimiento , Articulación de la Cadera/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Osteotomía/rehabilitación , Complicaciones Posoperatorias , Radiografía , Rango del Movimiento Articular , Reoperación , Estudios Retrospectivos , Factores de Riesgo , Análisis de Supervivencia , Resultado del Tratamiento
4.
J Bone Joint Surg Br ; 83(2): 274-7, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11284580

RESUMEN

Treatment with corticosteroids is a risk factor for non-traumatic avascular necrosis of the femoral head, but the pathological mechanism is poorly understood. Short-term treatment with high doses of methylprednisolone is used in severe neurotrauma and after kidney and heart transplantation. We investigated the effect of such treatment on the pattern of perfusion of the femoral head and of bone in general in the pig. We allocated 15 immature pigs to treatment with high-dose methylprednisolone (20 mg/kg per day intramuscularly for three days, followed by 10 mg/kg intramuscularly for a further 11 days) and 15 to a control group. Perfusion of the systematically subdivided femoral head, proximal femur, acetabulum, humerus, and soft tissues was determined by the microsphere technique. Blood flow in bone was severely reduced in the steroid-treated group. The reduction of flow affected all the segments and the entire epiphysis of the femoral head. No changes in flow were found in non-osseous tissue. Short-term treatment with high-dose methylprednisolone causes reduction of osseous blood flow which may be the pathogenetic factor in the early stage of steroid-induced osteonecrosis.


Asunto(s)
Huesos/irrigación sanguínea , Glucocorticoides/administración & dosificación , Metilprednisolona/administración & dosificación , Acetábulo/irrigación sanguínea , Animales , Epífisis/irrigación sanguínea , Femenino , Fémur/irrigación sanguínea , Cabeza Femoral/irrigación sanguínea , Húmero/irrigación sanguínea , Masculino , Porcinos
5.
Br J Sports Med ; 38(4): E14, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15273207

RESUMEN

The first case of little league shoulder syndrome in a cricket player is reported. The condition has been reported in baseball pitchers and is characterised by a proximal humeral epiphyseolysis.


Asunto(s)
Traumatismos en Atletas/etiología , Dolor de Hombro/etiología , Niño , Epífisis/lesiones , Humanos , Húmero/lesiones , Masculino , Rango del Movimiento Articular , Recurrencia , Síndrome
6.
Sportverletz Sportschaden ; 18(2): 80-4, 2004 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-15164293

RESUMEN

INTRODUCTION: The aim of the study was to achieve injury situations in European team handball with a video based method. METHODS: A video tape containing 59 injuries of an Olympic handball tournament were analyzed by two observers (sports-scientist, orthopaedic surgeon). The analysis was based on a method previously published by Teitz, which was developed to analyze ACL-injuries. The parameters body region, field position, contact/non-contact, offense/defense, field player/goal keeper were mainly used. RESULTS: The most injuries were localized at the head (N = 20), the lower limb (N = 15), thorax and abdomen (N = 9) and the upper limb (N = 9). Concerning the field, the most injuries were in the midfield (N = 20), followed by the left (N = 13) and right (N = 9) outside position. The injured players were mostly in the offense (84 %), and in the majority of cases the field players were affected (97 %). 86 % of the injuries accomplished by contact. CONCLUSION: The head has a high risk, predominantly of contact injury. Contact-injuries could only be reduced by strict decisions of the referees. Non-contact injuries should be prevented by a special coordinative training.


Asunto(s)
Traumatismos en Atletas/diagnóstico , Traumatismos Cerrados de la Cabeza/etiología , Traumatismos de la Pierna/etiología , Fotograbar/métodos , Medición de Riesgo/métodos , Grabación en Video/métodos , Traumatismos del Brazo/etiología , Humanos , Factores de Riesgo
7.
Bone Joint J ; 95-B(12): 1708-13, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24293604

RESUMEN

Avascular necrosis (AVN) is a serious complication of high-dose chemotherapy for haematological malignancy in childhood. In order to describe its incidence and main risk factors and to evaluate the current treatment options, we reviewed 105 children with a mean age of 8.25 years (1 to 17.8) who had acute lymphoblastic or acute myeloid leukaemia, or a non-Hodgkin's lymphoma. Overall, eight children (7.6%) developed AVN after a mean of 16.8 months (8 to 49). There were four boys and four girls with a mean age of 14.4 years (9.8 to 16.8) and a total of 18 involved sites, 12 of which were in the femoral head. All these children were aged > nine years (p < 0.001). All had received steroid treatment with a mean cumulative dose of prednisone of 5967 mg (4425 to 9599) compared with a mean of 3943 mg (0 to 18 585) for patients without AVN (p = 0.005). No difference existed between genders and no thrombophilic disorders were identified. Their initial treatment included 11 core decompressions and two bipolar hip replacements. Later, two salvage osteotomies were done and three patients (four hips) eventually needed a total joint replacement. We conclude that AVN mostly affects the weight-bearing epiphyses. Its risk increases with age and higher steroid doses. These high-risk patients may benefit from early screening for AVN.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias Hematológicas/tratamiento farmacológico , Osteonecrosis/inducido químicamente , Adolescente , Artroplastia de Reemplazo de Cadera , Niño , Preescolar , Descompresión Quirúrgica , Relación Dosis-Respuesta a Droga , Femenino , Necrosis de la Cabeza Femoral/inducido químicamente , Necrosis de la Cabeza Femoral/diagnóstico , Necrosis de la Cabeza Femoral/cirugía , Glucocorticoides/administración & dosificación , Glucocorticoides/efectos adversos , Humanos , Lactante , Masculino , Osteonecrosis/cirugía , Osteotomía/métodos , Prednisona/administración & dosificación , Prednisona/efectos adversos , Estudios Retrospectivos , Factores de Riesgo
8.
Z Orthop Unfall ; 149(2): 231-40; quiz 241-2, 2011 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-21469042

RESUMEN

Femoral head necrosis is an ischaemic bone necrosis of traumatic or nontraumatic pathogenesis which can lead to hip joint destruction in young age. It is today the indication for 10 % of all the total hip joint replacements. Known aetiologies of nontraumatic femoral head necrosis are alcoholism, steroids, sickle cell anaemia, caisson, and Gaucher's disease. Further risk factors are chemotherapy, chronic inflammatory bowel disease, systemic lupus erythematosus, and multiple sclerosis, in which also steroids are involved. Gravidity is another risk factor, but still idiopathic pathogenesis is found. In diagnosis, the ARCO-classification of the Association for the Research of Osseous Circulation is essential. While stage 0 can only be found histologically, the reversible early stage 1 shows MR signal changes. In the irreversible early stage 2, first native x-ray changes are seen as lower radiolucency reflects new bone apposition on dead trabeculae. In stage 3, subchondral fracture follows, and in stage 4 secondary arthritis of the hip. Established therapy in stage 1 is core decompression, physiotherapy, and more and more also bisphosphonates. Sufficient data to support extracorporeal shock wave therapy are still lacking. Stem cell therapy seems to be a promising new therapy method in stage 2. In stage 2 and 3 mainly proximal femoral osteotomies and (non)vascularised bone transplantation are performed. In stage 4, depending on size and location of the necrotic zone and pathology of the adjacent bone, resurfacing or short stem hip arthroplasty can be performed. However, conventional THA is still golden standard. The problem and challenge, however, is the often young patient age in femoral head necrosis. Especially chemotherapy-associated osteonecrosis in leukaemia is found in patients in their second decade of life. Therefore, the hip should be preserved as long as possible.


Asunto(s)
Artroplastia de Reemplazo de Cadera/instrumentación , Artroplastia de Reemplazo de Cadera/métodos , Diagnóstico por Imagen/métodos , Necrosis de la Cabeza Femoral/diagnóstico , Necrosis de la Cabeza Femoral/terapia , Humanos
9.
Z Orthop Unfall ; 149(4): 389-94, 2011 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-21739415

RESUMEN

BACKGROUND: Due to recent changes in the medical licencing act as well as to the introduction of a new model-course programme for medical studies, careers in medicine have become increasingly more attractive. However, there is still a dramatic shortage in younger generation physicians, especially within the surgical fields. The goal of this cross-sectional study was the gender-specific assessment of the ideal career wishes of students during medical school, with a focus being placed in orthopaedic trauma surgery. MATERIALS AND METHODS: During the winter semester of 2010/2011 an online questionnaire (www.surveymonkey.com) was created for students enrolled in their 3rd to 12th semester (n=887). The questionnaire consisted of 50 questions [Likert scale (LS); 5 = agree, 1 = disagree] along with 10 free response questions. The scope of these questions ranged from personal career goals, within the context of their learning environment, to general life goals and planning. With regard to career choice, a differentiation was made between students' ideal career choices/subjects (IS), which were based solely on personal affinity, and so-called reality-based subjects (RS), which students considered more practical and to which they were more likely to apply in the future. RESULTS: The response rate was 36,4% (n=323, 23,4 years, 6.3 semesters, 226 [70.0%] female [f] and 97 [30.0%] male [m]). A total of 206 students (63.8%; m=55.7% vs. f=66.7%; p=0.047) were able to pinpoint an IS, this percentage increased with increasing semester number (p=0.048). Overall, 29.1% of students indicated that their IS lay in the field of orthopaedic trauma, while 20.0% of men and 19.1% of women saw it as a realistic career path (RS). Throughout the course of their studies, from the 3rd semester to their practical year, a declining tendency was observed regarding the agreement between ideal and realistic career paths. Particularly evident was a decreasing interest in the field of orthopaedic trauma, beginning around the 9th semester and during the practical year, especially among the female student population. The reason for this shift seems multifactorial, ranging from concerns about family planning as well as the work load in a male-dominated field. By the time students enter their practical year, 13.5% of women and 15.4% of men were still certain in their choice to pursue a career in orthopaedic trauma (RS). CONCLUSIONS: It seems that there is great interest in the fields of orthopaedic trauma among both female and male students in the middle portion of their studies. Women, especially, tend to prefer a specialisation in this operative field early in the course of their studies. However, this pool of potential successors decreases dramatically with time, due to personal experiences garnered on the wards, expectations regarding career paths (male-dominated, long hours) as well as concerns about family planning. The most dramatic shift seems to occur during the practical year.


Asunto(s)
Actitud del Personal de Salud , Selección de Profesión , Educación de Postgrado en Medicina , Ortopedia/educación , Médicos Mujeres/psicología , Heridas y Lesiones/cirugía , Adulto , Servicios de Planificación Familiar , Femenino , Alemania , Objetivos , Humanos , Licencia Médica , Masculino , Factores Sexuales , Especialización , Encuestas y Cuestionarios , Carga de Trabajo/psicología , Adulto Joven
10.
Z Orthop Unfall ; 149(6): 646-52, 2011 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-22161737

RESUMEN

BACKGROUND: The G-DRG system reimburses sledge endoprosthetic implantations (UKA) at a much lower rate than surface replacements (TKA), at significantly different cost weights (CW). Therefore, when only G-DRG payments are considered, the complete endoprosthesis implantation produces higher gains. An orientation on these revenues alone, however, does not provide the basis for an economically sound decision-making process. The aim of this study is to present a comparison of the variable costs of the two procedures. MATERIAL AND METHODS: The mean cost and performance data of 28 Endo-Model UKA implantations and of 85 NexGen CR TKA replacements were compared with each other in 2007. RESULTS: From the perspective of the hospital, when the correct medical indication is present, UKA treatment is of greater economic advantage. In this way the total unit contribution margin can be improved, and although the relative weighting is comparatively low, the costs are significantly lower than in a comparative analysis of the TKA. CONCLUSION: For the desired maximisation of the unit contribution margin, assuming that it is the proper medical indication, the recommendation for the hospital would be implantation of the UKA. Considered from the economic perspective of gains and costs, the assumption that a TKA would be advantageous could not be confirmed in the present study.


Asunto(s)
Costos de la Atención en Salud/estadística & datos numéricos , Prótesis de la Rodilla/economía , Osteoartritis de la Rodilla/economía , Osteoartritis de la Rodilla/cirugía , Anciano , Femenino , Alemania , Humanos , Masculino , Resultado del Tratamiento
11.
Am J Psychiatry ; 146(9): 1243, 1989 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2764196
13.
Calcif Tissue Int ; 80(3): 184-91, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17334879

RESUMEN

Ovariectomy (OVX) in animal models is an accepted method to simulate postmenopausal osteoprosis. Vascular endothelial growth factor (VEGF) has been recently shown to play an important role during endochondral bone formation, hypertrophic cartilage remodeling, ossification, and angiogenesis. We hypothesized that reduced VEGF expression in bone contributes to OVX-induced bone loss and tested it in a miniature pig model and in vitro using human osteoblasts. Seventeen primiparous sows (Göttingen miniature pigs) were allocated to two experimental groups when they were 30 months old: a control group (n = 9) and an OVX group (n = 8). After 15 months, VEGF levels in lumbar vertebrae were measured by enzyme-linked immunosorbent assay and verified by Western blot analysis. VEGF and its receptor (VEGFR) were localized by immunohistochemistry. Expression of VEGF mRNA was analyzed by real-time reverse-transcription polymerase chain reaction. Differently sulfated glycosaminoglycans were localized in subchondral bone histochemically. Osteoblasts were immunopositive for VEGF. VEGF concentration in the vertebra was 27% lower in OVX miniature pigs. VEGFR-2 could be immunostained on osteoblasts. VEGF mRNA and protein were detectable in the lumbar vertebrae of all animals. In subchondral trabecular bone of OVX animals, significantly more islands of mineralized cartilage containing chondroitin 4- and 6-sulfate or keratan sulfate occurred compared to the control group. The occurrence of remnants of mineralized cartilage in subchondral bone of the OVX group may be caused by a delayed bone turnover due to low VEGF levels. In vitro experiments revealed an increase of VEGF in the supernatant of osteoblasts after incubation with estradiol. In conclusion, estrogen seems to be a key factor for regulation of VEGF expression in bone. Loss of VEGF due to menopause may be a reason for reduction of bone density.


Asunto(s)
Huesos/metabolismo , Estradiol/farmacología , Osteoblastos/metabolismo , Factor A de Crecimiento Endotelial Vascular/biosíntesis , Animales , Western Blotting , Cartílago/metabolismo , Estradiol/metabolismo , Femenino , Humanos , Osteoclastos/metabolismo , Ovariectomía , Receptores de Factores de Crecimiento Endotelial Vascular/metabolismo , Porcinos , Porcinos Enanos
15.
Zentralbl Chir ; 102(18): 1132-5, 1977.
Artículo en Alemán | MEDLINE | ID: mdl-919855

RESUMEN

A report is given on the therapy and results of 16 men with a mammary carcinoma during the last 15 years. The analysis shows the dependence of therapeutic treatment and prognosis of the state of tumour, especially of the metastases in regional lymphnodes. By applying a combined surgical-radiological treatment a survival time of 3 years could be reached in 8 patients and a survival time of 5 years in 5 patients.


Asunto(s)
Neoplasias de la Mama/terapia , Adulto , Neoplasias de la Mama/radioterapia , Neoplasias de la Mama/cirugía , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Pronóstico , Factores Sexuales
16.
Strahlentherapie ; 160(8): 505-7, 1984 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-6474525

RESUMEN

Late effects of radiotherapy are observed more frequently due to the improved results of the treatment of cancer and the resulting longer survival times. The big arteries, however, are only seldom attacked by late complications. The authors present a single case and stress the importance corresponding therapeutic action.


Asunto(s)
Disgerminoma/radioterapia , Claudicación Intermitente/diagnóstico por imagen , Traumatismos por Radiación/etiología , Adulto , Aortografía , Circulación Colateral/efectos de la radiación , Arteria Femoral/efectos de la radiación , Humanos , Masculino , Factores de Tiempo
17.
Zentralbl Gynakol ; 102(3): 181-5, 1980.
Artículo en Alemán | MEDLINE | ID: mdl-7211031

RESUMEN

Hyperprolactinaemic amenorrhoea was diagnosed in a patient, 33 years of age. It had been caused by retrosellar adamantinoma of the basis encephali. The radiological and histological findings are reported in this paper. This rare case is likely to reaffirm the urgent need for prolactin determination in every single case of amenorrhoea for brain tumour detection.


Asunto(s)
Ameloblastoma/complicaciones , Amenorrea/etiología , Neoplasias Encefálicas/complicaciones , Prolactina/sangre , Adulto , Ameloblastoma/diagnóstico , Neoplasias Encefálicas/diagnóstico , Femenino , Humanos
18.
Arch Orthop Trauma Surg ; 118(1-2): 45-9, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9833105

RESUMEN

In beagle dogs, the alterations of intraosseous pressure and blood supply in the femoral head that result from the administration of vasoactive substances were examined, and the changes were documented by magnetic resonance imaging (MRI). Vasoactive substance were infused into the medial and lateral circumflex femoral arteries of 12 beagle dogs. All infusions were done under standardised conditions with simultaneous measurements of venous blood flow and intraosseous pressure distribution in the proximal femur. The drugs were infused in three cycles of 30 min each separated by 30 min recovery periods, followed by MRI examination at the end of each experiment. At an intraosseous pressure of 14.3 (+/- 4.2) mmHg in the femoral head epiphysis (I), 11.6 (+/- 2.7) mmHg in the greater trochanter (II) and 9.3 (+/- 3.2) mmHg in the femoral shaft (III), a baseline flow of 96.2 (+/- 18.8, n = 12) ml/min was measured in the femoral vein. After infusing bradykinin at a concentration of 10(-6) moles, which is commonly known to lead to cerebral and subcutaneous oedema formation by vessel dilatation, the intraosseous pressure increased to (I): 49.1 (+/- 6.2) mmHg, (II): 42.5 (+/- 5.8) mmHg and (III): 38.3 (+/- 7.1) mmHg in the three measured femoral areas (n = 3). After the bradykinin injection, femoral vein flow increased to a peak value of 238.4 (+/- 43.4) ml/min and then dropped to 62.3 (+/- 14.2) ml/min after discontinuation of the bradykinin infusion. In a second and third series of tests, hyperosmolar (20% NaCl) and hypo-osmolar (distilled water) solutions were applied, also resulting in increased but lower mean intraosseous pressure values (17.3 +/- 4.1 and 25.7 +/- 5.1 ml/min, respectively) in all regions. When administering bradykinin, MRI scans taken immediately after completion of the experiment showed substantial oedema in the femoral muscular system, but without any changes of osseous signals in T1- or short time inversion recovery (STIR)-weighted images, nor did any changes occur when solutions of 20% NaCl or distilled H2O were injected. The results of our experiments demonstrate that acute increases of intraosseous pressure do not cause MRI signal alterations. We therefore conclude that in addition to the described pressure increase, other intraosseous alterations must occur to lead to the detectable signal changes found among patients with diagnosed femoral head necrosis. Finally, the short time period between the rise in intraosseous pressure and performing a conventional MRI may be one reason for missing the development of an intraosseous oedema. On the other hand, conventional MRI might have additional disadvantages for detecting intraosseous fluid compared with a dynamic imaging modality.


Asunto(s)
Bradiquinina/farmacología , Cabeza Femoral/efectos de los fármacos , Imagen por Resonancia Magnética/métodos , Vasodilatadores/farmacología , Animales , Enfermedades Óseas/inducido químicamente , Enfermedades Óseas/diagnóstico , Enfermedades Óseas/fisiopatología , Bradiquinina/administración & dosificación , Medios de Contraste , Perros , Edema/inducido químicamente , Edema/diagnóstico , Edema/fisiopatología , Femenino , Cabeza Femoral/irrigación sanguínea , Cabeza Femoral/patología , Cabeza Femoral/fisiología , Gadolinio DTPA , Soluciones Hipertónicas , Soluciones Hipotónicas , Infusiones Intraarteriales , Masculino , Presión , Flujo Sanguíneo Regional/efectos de los fármacos , Vasodilatadores/administración & dosificación
19.
Unfallchirurg ; 107(8): 671-5, 2004 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-15179556

RESUMEN

The aim of this study was to evaluate structural properties of native and elongated bovine anterior cruciate ligaments after the application of bipolar radiofrequency. Using a material testing machine typical load-elongation curves were used to determine the initial strength of untreated (group 1, n = 20) and elongated cruciate ligaments (group 2, n = 20) after treatment with bipolar radiofrequency (ArthroCare). After the application of a cyclic loading protocol (1000 x 400 N) elongation, yield load, maximal load, and stiffness were determined. Native ligaments served as a control group (group 3, n = 20). In both groups 4 mm reduction in length was caused by the application of radiofrequency. Elongation was significantly higher; yield load, maximal load, and stiffness of cruciate ligaments treated with radiofrequency (groups 1 and 2) were significantly reduced after the application of a cyclic loading protocol in comparison to the control group (p < 0.05). Group 2 ligaments showed the lowest values. The application of radiofrequency weakens the biomechanical properties of native and elongated cruciate ligaments significantly. When radiofrequency energy is used to shrink elongated cruciate ligaments, a nonaggressive rehabilitation protocol should be applied.


Asunto(s)
Ligamento Cruzado Anterior/fisiología , Ligamento Cruzado Anterior/efectos de la radiación , Ondas de Radio , Animales , Ligamento Cruzado Anterior/anatomía & histología , Fenómenos Biomecánicos/métodos , Bovinos , Fuerza Compresiva/fisiología , Fuerza Compresiva/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Elasticidad , Técnicas In Vitro , Dosis de Radiación , Estrés Mecánico , Resistencia a la Tracción/fisiología , Resistencia a la Tracción/efectos de la radiación
20.
Transfusion ; 18(1): 89-90, 1978.
Artículo en Inglés | MEDLINE | ID: mdl-625787

RESUMEN

A case is reported in which massive extracorporeal blood clotting necessitated the discontinuance of leukapheresis and loss of the product. An investigation of the cause of the massive clotting is reported along with suggested precautions to prevent similar occurrences in pheresis programs.


Asunto(s)
Coagulación Sanguínea , Plasmaféresis , Anticoagulantes/farmacología , Citratos/farmacología , Humanos
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