The reported clinical results following revision of failed cemented hip arthroplasties have varied. The most improtaint aspect of revision surgery, especially in case of removal of well injected femoral cement need not be daunting if certain essential principles are understanding. The prohlem is hasically that of a tuhe (cement) fixed within another tube (femur). Otherwise, any attempt to work between the two will cause the instruments to skid off the cement and penetrate the femoral cortex. Therefore, on the first step to deal with the problem and theoretical ground, we have investigated the mode of fracture in bone cement. Prior to this study, a comparision of various cement strength been published by A.J.C. Lee, University of Exetcr, UK is rviewed for our reference. As far as cement crack is concerned, the re are three modes of fracture, namely, mode I, mode II and mode III. As seen in the Fig. 5, mode I fracture is defined to be the fracture under symmetic loading, which is perpendicular to the crack surface. Mode II fracture is the fracture under anti-symmetric loading, which is parallel to the crack surface. In mode III, the loading is perpendicular to both crack surface and the plan of the paper. On the left is the situation shown when using osteotome to crush the cement Fig. 6. The prohlem here is of dynamical nature, however, this kind of prohlem has not been solved yet. Prediction of the direction of propagation is possible by assuming the static nature when the osteotome just gets inside the cement. Small element with distance and angle from the osteotome tip under stress is also,shown on the left, Here, th mode of fracture is mode I. ∂θθ is obstained from fracture mechanics as this, and the direction of crack propagation is given by solving ∂θθ = o,i.e, the direction of maximum ∂θθwhich turns out to be 0=0. When chisel is used, the mode of fracture is th combined mode, i. e. Mode I + Mode II (Fig. 7). In an angiogous approach to the previous one, aθθis obtained, thus, the direction of propagation is given by solving ∂θθ/∂θ = 0. which results in θ=(−)α, the half of the included angle of the chisel, Note, however, that the direction of propagation given here is the initial direction of crack propagation. In practiee, the crack often gets curves, however, this phenomena is governed by other factors neglected in this presentation, such as inhomogenity, state of stress of bone, cement and stem, etc, Thus, quantitative study is required in addition to so've these phenomenon.
Arthroplasty ; Hip Prosthesis ; Hip ; Mechanics

The authors studied 5 cases of idiopathic CNS hypersomnia who visited Division of Sleep Studies, Seoul National University Hospital in 1995. Detailed medical history was taken and nocturnal polysomnography(NPSG), multiple sleep latency test(MSLT)and human leukocyte antigen(HLA) typing were performed. Neither cataplexy nor hypnagogic hallucination was reported in all cases and in NPSGs, there were tendencies of increased sleep period time and decreased slow wave sleep time. In MSLT, all the subjects showed average sleep latencies less than 8 minutes without sleep-onset rapid eye movement period(SOREMP). In HLA typing, some correlation between idiopathis CNS hypersomnia and HLA DR4 was observed. in contrast to previous reports, overall treatment response with methylphenidate was remarkable. Therefore, the authors suggest that patients suspected of idiopathic CNS hypersomnia be actively evaluated and treated with rather optimistic perspective.
Cataplexy ; Central Nervous System* ; Disorders of Excessive Somnolence* ; Hallucinations ; Histocompatibility Testing ; Humans ; Leukocytes ; Methylphenidate ; Seoul ; Sleep, REM

We have experienced two cases of Wernicke's encephalopathy associated with hypere-mesis gravidarum. Delay in it's diagnosis caused a protracted illness and persisting neurol-ogic deficits. Because of its association with chronic alcoholism, possibility of Wernicke's encephalopathy may not be considered in early stage of disease. The clinical feature, the principle of management and the prevention of Wernicke's encephalopathy are discussed.
Alcoholism ; Diagnosis ; Female ; Hyperemesis Gravidarum* ; Pregnancy ; Wernicke Encephalopathy*

No abstract available.
Allografts* ; Animals ; Blood Transfusion* ; Cyclosporine* ; Lymphocyte Culture Test, Mixed* ; Rats*

Background: The major complications of spinal anesthesia are hypotension and bradycardia. In normal condition, hypotension stimulates baroreceptor reflex and compensatory tachycardia is occured. But during spinal anesthesia, there is possibility of a blockade of cardiac sympathetic nerve fibers which would result in increased vagal tone and depress compensatory baroreceptor reflex which is activated during hypotension. Atropine is an anticholinergic agent whose predominant cardiovascular effect was known as increasing heart rate at clinical dose. The purpose of this study was to evaluate hemodynamic effect of atropine during spinal anesthesia. Methods: We compared heart rate, systolic, diastolic and mean arterial pressures and cardiac output in 26 patients of ASA physical status 1, 2 before and after intravenous injection of atropine sulfate 0.01 mg/Kg during spinal anesthesia. Hemodynamic parameters were measured just prior to and 1, 2, 3, 4, 5, 10 minutes after atropine sulfate intravenous injection. The data were analyzed by repeated measures ANOVA. Results: Heart rate, mean blood pressure and diastolic blood pressure after atropine sulfate injection increased with significance. Conclusion: These findings suggest that during spinal anesthesia atropine is effective to produce tachycardia with a dosage of 0.01 mg/Kg in humans. Also hypotension might be improved because atropine makes mean blood pressure and diastolic blood pressure increase.
Anesthesia, Spinal* ; Arterial Pressure ; Atropine* ; Baroreflex ; Blood Pressure ; Bradycardia ; Cardiac Output ; Heart Rate ; Hemodynamics* ; Humans ; Hypotension ; Injections, Intravenous ; Nerve Fibers ; Tachycardia

Female urethral injury are very uncommon and encountered during traffic accident, trauma, instrumentation, operation and delivery. Treatment modalities are determined by the level of urethral injury. The result was better in the cases of rapid operative treatment than delayed one. In this report the clinical findings, patterns of injury and surgical managementof 4 cases were reviewed.
Accidents, Traffic ; Female* ; Humans

During the period of 9.5 years from September, 1985 to March, 1995, 32 cases with spontaneous closure in simple ventricular septal defect(VSD) were observed and evaluated at Yeungnam University Hospital, and those were confirmed by 2D-echocardiogram. The results were as follows: 1. Among these 32 cases, there were 23 cases(71.9%) of perimembranous VSD, 8 cases(25.0%) of muscular VSD and 1 case(3.1%) of subarterial VSD. Septal aneurysms appears to be main mechanism of spontaneous closure of VSD because of the presence of septal aneurysm in all cases with spontaneous ',;losure of a perimembranous VSD. 2. The size of the defect was variable in diameter, but 27 cases(81.2%) were less than 5 mm. 3. The mean age was 12.1 months at spontaneous closure with the range from 1 month old to 72 months. 4. The mean weight was 9.0 kg at spontaneous closure. 5.--Among these 32 cases, 3 cases had the clinical evidence of cardimegaly or congestive hert -failure during infancy. 6. Male to female sex ratio was 1.5:1
Aneurysm ; Estrogens, Conjugated (USP) ; Female ; Heart Septal Defects, Ventricular* ; Humans ; Male ; Sex Ratio

No abstract available.

No abstract available.
Ultrasonography*

No abstract available.
Cardioplegic Solutions* ; Heart Diseases* ; Heart* ; Hemodynamics* ; Humans