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Sample records for floating knee epidemiology

  1. Ipsilateral Floating Hip and Floating Knee - A Rare Entity

    PubMed Central

    Yashavantha Kumar, C; Nalini, K B; Nagaraj, Prashanth; Jawali, Abhijith

    2013-01-01

    Introduction: Ipsilateral floating hip and floating knee are very rare injuries. These injuries so uncommon that only three cases of similar kind have been reported. These injuries are due to high velocity injuries following motor vehicle accidents. Management of such complex injuries is a challenging task even in experienced hands as there are no standard treatment guidelines for such fractures. Case Report: We hereby report a 20 yr old male who sustained ipsilateral floating hip and ipsilateral floating knee injuries following motor vehicle accident. Patient was stabilized initially and later taken up for surgery. Patient was treated with interlocking nail for femur and tibia in the same sitting whereas acetabulam fracture was managed conservatively. At five months all the fractures united well with restoration of good range of motion in both hip and knee Conclusion: Ipsilateral floating knee and floating hip are very rare injuries seen following high velocity motor vehicle accidents. There are no standard guidelines for treatment of those fractures as only a few cases of similar kind have been reported in literature. Early fixation and aggressive mobilization ensures fracture union and fewer complications. PMID:27298908

  2. Management of the Floating Knee in Polytrauma Patients

    PubMed Central

    Bertrand, M.L.; Andrés-Cano, P.

    2015-01-01

    Ipsilateral fracture of the femur and tibia, or floating knee, is a rare injury that is found almost exclusively in polytrauma or high-energy trauma patients. It presents a combination of diaphyseal, metaphyseal and intra-articular fractures of the femur and tibia, with a high incidence of neurovascular, ligamentous and soft-tissue injuries. The functional outcome and, in some cases, the life, of such polytrauma patients depends largely on a correct therapeutic approach being taken. In general, the treatment decided upon will depend on the individual characteristics present, regarding aspects such as the patient’s general condition, the fracture line and the state of the soft tissues. The treatment provided may be the same as when single fractures are presented, but it is often necessary to consider whether certain techniques or surgical approaches may interfere with other lines of treatment. It is essential at all times to take into consideration the associated injuries and complications before deciding upon a treatment strategy. Ligamentous injuries play an important role in these injuries, much more so than when fractures occur singly. Therefore, these injuries require management by an experienced multidisciplinary team. PMID:26312119

  3. Epidemiology and Impact of Knee Injuries in Major and Minor League Baseball Players.

    PubMed

    Dahm, Diane L; Curriero, Frank C; Camp, Christopher L; Brophy, Robert H; Leo, Tony; Meister, Keith; Paletta, George A; Steubs, John A; Mandelbaum, Bert R; Pollack, Keshia M

    2016-01-01

    Few studies have explored the frequency and impact of lower extremity injuries, such as those to the knee, among professional baseball players. The purpose of this study was to detail the epidemiology of knee injuries in Major League Baseball (MLB) and Minor League Baseball (MiLB) players during the 2011-2014 seasons. It was hypothesized that knee injuries are a common occurrence in these athletes, and represent a significant source of time away from play. The MLB Health and Injury Tracking System database was searched to identify all patients diagnosed with knee injuries during the 2011-2014 seasons. All injuries that occurred during the preseason, regular season, and postseason that resulted in time away from play were included. Injury data analyzed included total number of knee injuries, specific diagnoses, injury mechanisms, locations, player positions, and time lost. Descriptive statistics were conducted and injury rates per athlete-exposures were calculated. During the 2011-2014 seasons, a total of 2171 knee injuries occurred in MLB and MiLB players, representing 6.5% of all injuries in professional baseball. The knee injury rate across both the MLB and MiLB was 1.2 per 1000 athlete-exposures. The mean number of days missed per injury across both leagues was 16.2 with a total of 30,449 days of missed play amongst all athletes over the 4 seasons. Injuries to the knee were the fifth most common cause of missed time in all of baseball, and the fourth most common reason for missed games in the MLB alone. Approximately 12% of all injuries required surgical intervention. The most common mechanism of injury was noncontact (44%), and base runners were injured more frequently than any other position (24%). The infield (30%) and home plate (23%) were the most common locations in which injuries occurred. These data can be utilized for targeted injury prevention initiatives. PMID:26991584

  4. Chronic Multiple Knee Ligament Injuries: Epidemiological Analysis of More Than One Hundred Cases

    PubMed Central

    Bispo, Rosalvo Zosimo; Kawano, Cezar Teruyuki; Guedes, Alexandre Vieira

    2008-01-01

    INTRODUCTION Diagnosis and treatment of multiple ligament injuries of the knee remain a real challenge for most surgeons. OBJECTIVE To find out the epidemiological profile of patients surgically treated at a Reference Service with more than one chronic ligament injury in the knee joint. MATERIALS AND METHODS Of a total of 978 operated patients, 109 presented at least two associated ligament injuries in the same knee. Demographic and clinical variables were evaluated. RESULTS The anterior cruciate ligament group presented a larger number of cases of ligament injuries related with sports practice and falls, while the posterior cruciate ligament and anterior cruciate ligament + posterior cruciate ligament groups presented more cases related to traffic accidents and trauma with object (weight on the knee) (p<0.001). The varus group presented significantly higher values of time since injury (p<0.01). In the group with new anterior cruciate ligament injury (neoligament) associated with other ligament injuries the disruption times were higher, showing statistical significance (p<0.001). CONCLUSIONS Anterior cruciate ligament injury associated with other ligament injuries other than posterior cruciate ligament injury are related to sports practice and falls. Posterior cruciate ligament injury associated to other ligament injuries, including or not anterior cruciate ligament injury, are related to traffic accidents and direct trauma caused by an object on the knee. Significant delay between primary ligament injuries and their reconstructions generates varus deformity of the affected knee. In spite of the large delay in seeking medical treatment, few patients with neoligament anterior cruciate ligament injury and other combined disruptions will develop varus deformity. PMID:18297200

  5. The epidemiology of failure in total knee arthroplasty: avoiding your next revision.

    PubMed

    Khan, M; Osman, K; Green, G; Haddad, F S

    2016-01-01

    Total knee arthroplasty (TKA) is a cost effective and extremely successful operation. As longevity increases, the demand for primary TKA will continue to rise. The success and survivorship of TKAs are dependent on the demographics of the patient, surgical technique and implant-related factors. Currently the risk of failure of a TKA requiring revision surgery ten years post-operatively is 5%. The most common indications for revision include aseptic loosening (29.8%), infection (14.8%), and pain (9.5%). Revision surgery poses considerable clinical burdens on patients and financial burdens on healthcare systems. We present a current concepts review on the epidemiology of failed TKAs using data from worldwide National Joint Registries. PMID:26733654

  6. Reliability and Validity of the Anterior Knee Pain Scale: Applications for Use as an Epidemiologic Screener

    PubMed Central

    2016-01-01

    A screening instrument’s ability to provide clinicians with consistent and reproducible information is crucial to intervention. Despite widespread acceptance and clinical use of the Kujala Anterior Knee Pain Scale (AKPS) in orthopedics and sports medicine, few studies have reported on its reliability and no such studies have concentrated on child or adolescent samples exclusively, segments of the population for which this instrument is often used. The purpose of the current study was to describe and report on the reliability and validity of the AKPS for use with high school female athletes participating in interscholastic athletics. The study was a secondary analysis of prospective epidemiologic data using established scale validation methods. The records of 414 female athletes 11.0 to 18.1 years of age (Mean 13.9 yrs, SD = 1.7 yrs) were used for analysis. Four different approaches to scoring and scale reduction of the AKPS were evaluated, including the original, ordinal 13-item form, a modified, ordinal 6-item form, a modified, dichotomous 13-item form, and a modified, dichotomous 6-item form. Three different types of reliability (internal consistency, equivalence across forms, standard error of measurement) and one type of validity (criterion-related) were estimated for the AKPS in the current sample. The four scoring formats of the AKPS scale were found to have high internal consistency (αcoef = 0.83 to 0.91), equivalence across the short and long forms (r = 0.98), acceptable standard errors of measurement (0.82 to 3.00), and moderate to high criterion related validity—as determined by physican’s diagnosis: 0.92 (13-item form), 0.90 (6-item form). The Kujala AKPS is a valid and reliable measure of anterior knee pain and appropriate for use as an epidemiologic screening tool with adolescent female athletes. PMID:27441381

  7. Reliability and Validity of the Anterior Knee Pain Scale: Applications for Use as an Epidemiologic Screener.

    PubMed

    Ittenbach, Richard F; Huang, Guixia; Barber Foss, Kim D; Hewett, Timothy E; Myer, Gregory D

    2016-01-01

    A screening instrument's ability to provide clinicians with consistent and reproducible information is crucial to intervention. Despite widespread acceptance and clinical use of the Kujala Anterior Knee Pain Scale (AKPS) in orthopedics and sports medicine, few studies have reported on its reliability and no such studies have concentrated on child or adolescent samples exclusively, segments of the population for which this instrument is often used. The purpose of the current study was to describe and report on the reliability and validity of the AKPS for use with high school female athletes participating in interscholastic athletics. The study was a secondary analysis of prospective epidemiologic data using established scale validation methods. The records of 414 female athletes 11.0 to 18.1 years of age (Mean 13.9 yrs, SD = 1.7 yrs) were used for analysis. Four different approaches to scoring and scale reduction of the AKPS were evaluated, including the original, ordinal 13-item form, a modified, ordinal 6-item form, a modified, dichotomous 13-item form, and a modified, dichotomous 6-item form. Three different types of reliability (internal consistency, equivalence across forms, standard error of measurement) and one type of validity (criterion-related) were estimated for the AKPS in the current sample. The four scoring formats of the AKPS scale were found to have high internal consistency (αcoef = 0.83 to 0.91), equivalence across the short and long forms (r = 0.98), acceptable standard errors of measurement (0.82 to 3.00), and moderate to high criterion related validity-as determined by physican's diagnosis: 0.92 (13-item form), 0.90 (6-item form). The Kujala AKPS is a valid and reliable measure of anterior knee pain and appropriate for use as an epidemiologic screening tool with adolescent female athletes. PMID:27441381

  8. Prospective epidemiological study of basketball injuries during one competitive season: ankle sprains and overuse knee injuries.

    PubMed

    Cumps, Elke; Verhagen, Evert; Meeusen, Romain

    2007-01-01

    This prospective cohort study aims to assess the overall incidence of acute and overuse basketball injuries and identifies risk factors associated with ankle sprains and knee overuse injuries. In total, 164 senior players (23.7 years ± 7.0) of all levels of play, and including both men and women, participated voluntarily during one season. A total of 139 acute and 87 overuse injuries were reported, resulting in an overall injury incidence of 9.8 (8.5 to 11.1) per 1,000 hours. The incidence of acute injuries was 6.0/1,000 hours. Ankle sprains (n = 34) accounted for most acute injuries, and 52.9% of all players with ankle sprains reported a previous ankle sprain. Relative Risks (RR) and Odds Ratio (OR) with their 95% Confidence Intervals (CI) were calculated to determine significant differences. Landing on an opponent's foot was the major inciting event, significantly more so than non contact mechanisms (RR=2.1 [95% CI: 1.0-4.2]). Acute knee injuries resulted in the highest playing absence (7 weeks 2 days ± 9 weeks 1 day). Overuse injury incidence was 3.8/1,000 hours. The knee (1.5/1,000 hours) was the most common site. Forward players sustained less knee overuse injuries than players of all other playing positions, and significantly less than center players (OR=0.5 [95% CI: 0.2-0.9]). This study showed that ankle sprains and overuse knee injuries are the most common injuries in basketball, both accounting for 14.8%. Injury prevention programmes however should not concentrate on those injuries only, but might one to consider that acute knee injuries, in spite of the fact that they occur less frequently, also merit further research. Key pointsAnkle sprains are the most common acute injuries in basketball with the inciting event being landing on an opponent's foot or changing direction.Anterior knee pain is the most common overuse injury. Etiologic factors are well described in literature, but prevention strategies are lacking.Acute knee injuries account for the

  9. Floating patella associated with lymphoedema

    PubMed Central

    Vun, Shen Hwa; Bayam, Levent; Drampalos, Efstathios; Jesry, Mohammed; Fadel, George

    2015-01-01

    Ipsilateral injury of more than one component of the knee extensor apparatus is rare. It is mostly associated with previous trauma, surgery, immunosuppression therapy and systemic disease. We present the first documented case of a spontaneous bifocal disruption of the knee extensor apparatus (i.e. floating patella) associated with lymphoedema. This case highlights the importance of considering lymphoedema as another risk factor for rupture of the knee extensor apparatus. It also highlights the importance of assessing all components of the knee extensor apparatus in patients presenting with acute knee injuries. PMID:25802253

  10. Epidemiology of hip and knee pain in a community based sample of Italian persons aged 65 and older1

    PubMed Central

    Cecchi, F.; Mannoni, A.; Molino-Lova, R.; Ceppatelli, S.; Benvenuti, E.; Bandinelli, S.; Lauretani, F.; Macchi, C.; Ferrucci, L.

    2016-01-01

    Summary Objective To describe prevalence, characteristics and correlates of hip pain (HP) and knee pain (KP) in an Italian community based cohort aged 65 and older (65+). Method Baseline survey (1998–2000), population-based study in the Chianti area (Tuscany, Italy); 1299 persons aged 65+ were selected from the city registry of Greve in Chianti and Bagno a Ripoli (multistage sampling method); 1006 participants (564 women and 442 men, age 75.2 ± 7.1) provided information for this analysis. Persons reporting HP/KP in the past 4 weeks were recorded and their Western Ontario and McMaster University Osteoarthritis Index pain score (WPS-range 0–20) calculated. Potential correlates of HP/KP, including clinical, lifestyle and psycho-social features and physical measures, were tested in age- and gender-adjusted regression analyses and then entered a multivariate regression model. Results HP was reported by 11.9% participants, while 22.4% reported KP and 7.2% both conditions. Climbing/descending stairs and walking were the activities eliciting more severe pain in either condition. Average WPSs were 5.6 ± 3.5 for HP and 5.4 ± 10.4 for KP. Both HP and KP were related to back pain, reduced hip abduction, reduced muscle power and increased trunk flexibility. HP was also related to KP and poor self-rated health (SRH), while KP to HP, foot pain, high body mass index, reduced knee passive flexion and knee extension torque, low education. Conclusion In a community sample of an Italian persons aged 65+, the prevalence of KP almost doubled that of HP. While both conditions were related to pain in other joints and specific joint impairment, only HP was related to poor SRH, and only KP to mechanical overload. PMID:18343164

  11. Stools - floating

    MedlinePlus

    ... absorption of nutrients ( malabsorption ) or too much gas (flatulence). Considerations Most causes of floating stools are harmless. ... Bailey J. FPIN's Clinical Inquiries: Effective management of flatulence. Am Fam Physician Ohge H, Levitt MD. Intestinal ...

  12. Knee pain

    MedlinePlus

    ... the front of your knee around the kneecap Torn ligament. An anterior cruciate ligament (ACL) injury, or ... into your knee, swelling, or an unstable knee. Torn cartilage (a meniscus tear ). Pain felt on the ...

  13. An expert-based job exposure matrix for large scale epidemiologic studies of primary hip and knee osteoarthritis: The Lower Body JEM

    PubMed Central

    2014-01-01

    Background When conducting large scale epidemiologic studies, it is a challenge to obtain quantitative exposure estimates, which do not rely on self-report where estimates may be influenced by symptoms and knowledge of disease status. In this study we developed a job exposure matrix (JEM) for use in population studies of the work-relatedness of hip and knee osteoarthritis. Methods Based on all 2227 occupational titles in the Danish version of the International Standard Classification of Occupations (D-ISCO 88), we constructed 121 job groups comprising occupational titles with expected homogeneous exposure patterns in addition to a minimally exposed job group, which was not included in the JEM. The job groups were allocated the mean value of five experts’ ratings of daily duration (hours/day) of standing/walking, kneeling/squatting, and whole-body vibration as well as total load lifted (kg/day), and frequency of lifting loads weighing ≥20 kg (times/day). Weighted kappa statistics were used to evaluate inter-rater agreement on rankings of the job groups for four of these exposures (whole-body vibration could not be evaluated due to few exposed job groups). Two external experts checked the face validity of the rankings of the mean values. Results A JEM was constructed and English ISCO codes were provided where possible. The experts’ ratings showed fair to moderate agreement with respect to rankings of the job groups (mean weighted kappa values between 0.36 and 0.49). The external experts agreed on 586 of the 605 rankings. Conclusion The Lower Body JEM based on experts’ ratings was established. Experts agreed on rankings of the job groups, and rankings based on mean values were in accordance with the opinion of external experts. PMID:24927760

  14. Knee Bracing: What Works?

    MedlinePlus

    MENU Return to Web version Knee Bracing: What Works? Knee Bracing: What Works? What are knee braces? Knee braces are supports ... have arthritis in their knees. Do knee braces work? Maybe. Companies that make knee braces claim that ...

  15. Knee Replacement

    MedlinePlus

    ... doctor may recommend it if you have knee pain and medicine and other treatments are not helping you anymore. When you have a total knee replacement, the surgeon removes damaged cartilage and bone ...

  16. Knee Problems

    MedlinePlus

    ... cartilage, a tough, elastic material that helps absorb shock and allows the knee joint to move smoothly. ... The two menisci in each knee act as shock absorbers, cushioning the lower part of the leg ...

  17. Knee Injuries

    MedlinePlus

    ... Sprains A sprain means you've stretched or torn a ligament. Common knee sprains usually involve damage ... A strain means you've partly or completely torn a muscle or tendon. With knee strains, you ...

  18. Prophylactic Knee Braces: Where Do They Stand?

    ERIC Educational Resources Information Center

    McCarthy, Paul

    1988-01-01

    The effectiveness of knee braces in preventing knee injuries in football is inconclusive. This article reviews research from epidemiologic, cadaver, and surrogate studies; discusses reasons for conflicting study results, including research design problems; and describes alternative approaches that have been suggested. (IAH)

  19. Obesity and osteoarthritis in knee, hip and/or hand: An epidemiological study in the general population with 10 years follow-up

    PubMed Central

    Grotle, Margreth; Hagen, Kare B; Natvig, Bard; Dahl, Fredrik A; Kvien, Tore K

    2008-01-01

    Background Obesity is one of the most important risk factors for osteoarthritis (OA) in knee(s). However, the relationship between obesity and OA in hand(s) and hip(s) remains controversial and needs further investigation. The purpose of this study was to investigate the impact of obesity on incident osteoarthritis (OA) in hip, knee, and hand in a general population followed in 10 years. Methods A total of 1854 people aged 24–76 years in 1994 participated in a Norwegian study on musculoskeletal pain in both 1994 and 2004. Participants with OA or rheumatoid arthritis in 1994 and those above 74 years in 1994 were excluded, leaving n = 1675 for the analyses. The main outcome measure was OA diagnosis at follow-up based on self-report. Obesity was defined by a body mass index (BMI) of 30 and above. Results At 10-years follow-up the incidence rates were 5.8% (CI 4.3–7.3) for hip OA, 7.3% (CI 5.7–9.0) for knee OA, and 5.6% (CI 4.2–7.1) for hand OA. When adjusting for age, gender, work status and leisure time activities, a high BMI (> 30) was significantly associated with knee OA (OR 2.81; 95%CI 1.32–5.96), and a dose-response relationship was found for this association. Obesity was also significantly associated with hand OA (OR 2.59; 1.08–6.19), but not with hip OA (OR 1.11; 0.41–2.97). There was no statistically significant interaction effect between BMI and gender, age or any of the other confounding variables. Conclusion A high BMI was significantly associated with knee OA and hand OA, but not with hip OA. PMID:18831740

  20. The epidemiological and clinical features of primary giant cell tumor around the knee: A report from the multicenter retrospective study in china

    PubMed Central

    Lin, Fengsong; Hu, Yongcheng; Zhao, Liming; Zhang, Huilin; Yu, Xiuchun; Wang, Zhen; Ye, Zhaoming; Wu, Sujia; Guo, Shibing; Zhang, Guochuan; Wang, Jinghua

    2016-01-01

    Objectives We aimed to determine the demographic characteristics of giant cell tumor around the knee in China. Methods Between March 2000 and June 2014, patients with primary giant cell tumor around the knee were recruited from 6 institutions located in different regions of China, and were reviewed retrospectively the clinical features according to gender and age. Results 334 qualified patients were included in this study. The sex ratio was 1.14:1 (178/156), with mean ages of 36.9 years in men and 33.1 years in women, constituting a significant difference (P=0.007). The prevalence of pathological fracture was 32.9% overall (28.7% in men and 37.8% in women). The prevalence of simple fracture was significantly higher in women (26.3%) than in men (15.2%), P=0.042. Tumor location and staging did not differ significantly according to sex (P>0.05). However, comparing with >40 years old, those patients aged ≤40 were more likely to have a right knee tumor (56.7% vs. 44.7%, P=0.042), less likely to have Enneking stage 3 disease (18.6% vs. 35.0%, P=0.005), and less likely to have both soft-tissue extension and a mass (18.6% vs. 34.0%, P=0.009). Conclusions Giant cell tumor around the knee was more common in men than in women, although female patients were younger on average. Further, cases among patients ≤40 years old were observed to be milder than cases among older patients. The results suggest that efficient treatment and preservation of function should both be valued for young patients with giant cell tumor around the knee. PMID:26998425

  1. Floating Point Control Library

    Energy Science and Technology Software Center (ESTSC)

    2007-08-02

    Floating Point Control is a Library that allows for the manipulation of floating point unit exception masking funtions control exceptions in both the Streaming "Single Instruction, Multiple Data" Extension 2 (SSE2) unit and the floating point unit simultaneously. FPC also provides macros to set floating point rounding and precision control.

  2. Knee arthroscopy - series (image)

    MedlinePlus

    ... knee problems such as: a torn knee disc (meniscus) a damaged knee bone (patella) a damaged ligament ... surgeon can see the ligaments, the knee disc (meniscus), the knee bone (patella), the lining of the ...

  3. Knee injuries in female athletes.

    PubMed

    Hutchinson, M R; Ireland, M L

    1995-04-01

    Female athletes are at increased risk for certain sports-related injuries, particularly those involving the knee. Factors that contribute to this increased risk are the differences in sports undertaken and in gender anatomy and structure. Gender differences include baseline level of conditioning, lower extremity alignment, physiological laxity, pelvis width, tibial rotation and foot alignment. Sports like gymnastics and cheerleading create a noncontact environment, but can result in significant knee injuries. In quick stopping and cutting sports, females have an increased incidence of anterior cruciate ligament (ACL) injury by noncontact mechanisms. Patellofemoral (PF) disorders are also very common in female athletes. Awareness of these facts helps the sports medicine professional make an accurate diagnosis and institute earlier treatment-focused rehabilitation with or without surgery. Further prospective and retrospective research is needed in areas of epidemiology, mechanisms, severity and types of knee injuries. The goal is to lessen the severity of certain knee injuries and to prevent others. PMID:7604201

  4. WindWaveFloat

    SciTech Connect

    Weinstein, Alla

    2011-11-01

    Presentation from the 2011 Water Peer Review includes in which principal investigator Alla Weinstein discusses project progress in development of a floating offshore wind structure - the WindFloat - and incorporation therin of a Spherical Wave Energy Device.

  5. Floating: sink or swim.

    PubMed

    Pronger, L

    1995-12-01

    Budget restrictions, fewer human resources and fluctuating patient populations have combined to increase the practice of floating general duty nurses. Floating occurs when a nurse from an overstaffed unit, based on patient load, is required to work in another unit that is understaffed. Floating is not a new practice, but it has always been an emotionally charged issue. Today, with more float pool nurses seeking the security of a permanent position in a home unit, the issue has increased in intensity. PMID:8713148

  6. The Design of Floats

    NASA Technical Reports Server (NTRS)

    Sottorf, W

    1938-01-01

    Following a summary of the multiplicity of domestic and foreign floats and a brief enumeration of the requirements of floats, the essential form parameters and their effect on the qualities of floats are detailed. On this basis a standard float design is developed which in model families with varying length/beam ratio and angle of dead rise is analyzed by an experimental method which permits its best utilization on any airplane.

  7. Runner's Knee

    MedlinePlus

    ... Over the summer he bought a pair of running shoes and took up jogging. He started with ... bending the knee — when walking, kneeling, squatting, or running, for example. Walking or running downhill or even ...

  8. Knee arthroscopy

    MedlinePlus

    ... is cartilage that cushions the space between the bones in the knee. Surgery is done to repair or remove it. Torn or damaged anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) Torn or damaged collateral ligament Swollen (inflamed) or ...

  9. Knee Injuries and Disorders

    MedlinePlus

    Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty ...

  10. Knee Dislocations

    PubMed Central

    Schenck, Robert C.; Richter, Dustin L.; Wascher, Daniel C.

    2014-01-01

    Background: Traumatic knee dislocation is becoming more prevalent because of improved recognition and increased exposure to high-energy trauma, but long-term results are lacking. Purpose: To present 2 cases with minimum 20-year follow-up and a review of the literature to illustrate some of the fundamental principles in the management of the dislocated knee. Study Design: Review and case reports. Methods: Two patients with knee dislocations who underwent multiligamentous knee reconstruction were reviewed, with a minimum 20-year follow-up. These patients were brought back for a clinical evaluation using both subjective and objective measures. Subjective measures include the following scales: Lysholm, Tegner activity, visual analog scale (VAS), Short Form–36 (SF-36), International Knee Documentation Committee (IKDC), and a psychosocial questionnaire. Objective measures included ligamentous examination, radiographic evaluation (including Telos stress radiographs), and physical therapy assessment of function and stability. Results: The mean follow-up was 22 years. One patient had a vascular injury requiring repair prior to ligament reconstruction. The average assessment scores were as follows: SF-36 physical health, 52; SF-36 mental health, 59; Lysholm, 92; IKDC, 86.5; VAS involved, 10.5 mm; and VAS uninvolved, 2.5 mm. Both patients had excellent stability and were functioning at high levels of activity for their age (eg, hiking, skydiving). Both patients had radiographic signs of arthritis, which lowered 1 subject’s IKDC score to “C.” Conclusion: Knee dislocations have rare long-term excellent results, and most intermediate-term studies show fair to good functional results. By following fundamental principles in the management of a dislocated knee, patients can be given the opportunity to function at high levels. Hopefully, continued advances in the evaluation and treatment of knee dislocations will improve the long-term outcomes for these patients in the

  11. [Jumper's knee].

    PubMed

    Hagner, W; Sosnowski, S; Kaziński, W; Frankowski, S

    1993-01-01

    A series of 30 athletes aged about 16 years on an average, exposed to activities putting a strain on the patellar tendon during training has been examined. They were involved in competitive sports for 3 years on an average. In 27 per cent of them jumpers knee symptoms have been found. PMID:7671664

  12. "Floating shoulder" injuries.

    PubMed

    Heng, Kenneth

    2016-12-01

    "Floating shoulder" is a rare injury complex resulting from high-energy blunt force trauma to the shoulder, resulting in scapulothoracic dissociation. It is commonly associated with catastrophic neurovascular injury. Two cases of motorcyclists with floating shoulder injuries are described. PMID:26961729

  13. Float Zone Workshop

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.

    1980-01-01

    A summary of the Analytical Float Zone Experiment System (AFZES) concept is presented. The types of experiments considered for such a facility are discussed. Reports from various industrial producers and users of float zone material are presented. Special emphasis is placed on state-of-the-art developments in low gravity manufacturing and their applications to space processing.

  14. Knee joint replacement - series (image)

    MedlinePlus

    ... than 3 blocks because of knee pain Loose knee prosthesis Some knee fractures ... an incision over the affected knee. The patella (knee cap) is moved ... helps the prosthesis to adhere better. The two parts of the ...

  15. Knee microfracture surgery

    MedlinePlus

    Cartilage regeneration - knee ... Three types of anesthesia may be used for knee arthroscopy surgery: Medicine to relax you, and shots of painkillers to numb the knee Spinal (regional) anesthesia General anesthesia (you will be ...

  16. Knee CT scan

    MedlinePlus

    CAT scan - knee; Computed axial tomography scan - knee; Computed tomography scan - knee ... Saunders; 2015:chap 93. Shaw AS, Prokop M. Computed tomography. In: Adam A, Dixon AK, Gillard JH, Schaefer- ...

  17. Knee joint replacement

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002974.htm Knee joint replacement To use the sharing features on this page, please enable JavaScript. Knee joint replacement is a surgery to replace a knee ...

  18. Knee pain (image)

    MedlinePlus

    ... front of the knee can be due to bursitis, arthritis, or softening of the patella cartilage as ... knee. Overall knee pain can be due to bursitis, arthritis, tears in the ligaments, osteoarthritis of the ...

  19. Floating emitter solar cell

    NASA Technical Reports Server (NTRS)

    Chih, Sah (Inventor); Cheng, Li-Jen (Inventor)

    1987-01-01

    A front surface contact floating emitter solar cell transistor is provided in a semiconductor body (n-type), in which floating emitter sections (p-type) are diffused or implanted in the front surface. Between the emitter sections, a further section is diffused or implanted in the front surface, but isolated from the floating emitter sections, for use either as a base contact to the n-type semiconductor body, in which case the section is doped n+, or as a collector for the adjacent emitter sections.

  20. Floating Magnet Demonstration.

    ERIC Educational Resources Information Center

    Wake, Masayoshi

    1990-01-01

    A room-temperature demonstration of a floating magnet using a high-temperature superconductor is described. The setup and operation of the apparatus are described. The technical details of the effect are discussed. (CW)

  1. Float-in powerhouses

    SciTech Connect

    Makela, G.A.

    1983-06-01

    The nation's inland waterway system affords a means of transporting large objects limited only by channel depth, size of locks and bridge clearances. The concept of prefabricating standardized, hydroelectric powerhouses at shipyards, transporting them along the inland waterways and installing them at navigation dams without powerhouses was examined for the McClellan-Kerr Arkansas River Navigation system. It was found that construction costs for the float-in design was very close to those of conventional sitebuilt design. Experience at Greenup Dam on the Ohio River where a float-in powerhouse has been installed indicated that construction time could be reduced if the float-in design was used. This time saving, use of standardized designs and construction of the float-in module at a shipyard may offer advantages that should be examined in more detailed when the power potential of the nation's low navigation dams is assessed.

  2. Concrete production floating platforms

    SciTech Connect

    Letourneur, O.; Falcimaigne, J.

    1981-01-01

    The floating production platforms operating in the North Sea are adapted from drilling semisubmersibles which allow only a limited payload capacity. Experience of concrete production platforms constructed for the North Sea has led Sea Tank Co. to propose a floating platform which offers large payload and oil storage capacities similar to those of existing fixed platforms. Sea Tank Co. and Institut Francais du Petrole joined forces in early 1976 to study the feasibility of a concrete floating production platform incorporating the structure and the production riser together. The results of this 3-yr program show that the concrete floating structure is economically attractive for permanent utilization on a production site. Furthermore, concrete has definite advantages over other materials, in its long term behavior.

  3. Micromechanisms with floating pivot

    DOEpatents

    Garcia, Ernest J.

    2001-03-06

    A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use floating pivot structures to relieve some of the problems encountered in the use of solid flexible pivots.

  4. Stabilized floating platforms

    DOEpatents

    Thomas, David G.

    1976-01-01

    The subject invention is directed to a floating platform for supporting nuclear reactors and the like at selected offshore sites. The platform is provided with a stabilizer mechanism which significantly reduces the effects of wave action upon the platform and which comprises a pair of relatively small floats attached by rigid booms to the platform at locations spaced therefrom for reducing wave pitch, acceleration, and the resonance period of the wave.

  5. Failure of aseptic revision total knee arthroplasties

    PubMed Central

    Leta, Tesfaye H; Lygre, Stein Håkon L; Skredderstuen, Arne; Hallan, Geir; Furnes, Ove

    2015-01-01

    Background and purpose In Norway, the proportion of revision knee arthroplasties increased from 6.9% in 1994 to 8.5% in 2011. However, there is limited information on the epidemiology and causes of subsequent failure of revision knee arthroplasty. We therefore studied survival rate and determined the modes of failure of aseptic revision total knee arthroplasties. Method This study was based on 1,016 aseptic revision total knee arthroplasties reported to the Norwegian Arthroplasty Register between 1994 and 2011. Revisions done for infections were not included. Kaplan-Meier and Cox regression analyses were used to assess the survival rate and the relative risk of re-revision with all causes of re-revision as endpoint. Results 145 knees failed after revision total knee arthroplasty. Deep infection was the most frequent cause of re-revision (28%), followed by instability (26%), loose tibial component (17%), and pain (10%). The cumulative survival rate for revision total knee arthroplasties was 85% at 5 years, 78% at 10 years, and 71% at 15 years. Revision total knee arthroplasties with exchange of the femoral or tibial component exclusively had a higher risk of re-revision (RR = 1.7) than those with exchange of the whole prosthesis. The risk of re-revision was higher for men (RR = 2.0) and for patients aged less than 60 years (RR = 1.6). Interpretation In terms of implant survival, revision of the whole implant was better than revision of 1 component only. Young age and male sex were risk factors for re-revision. Deep infection was the most frequent cause of failure of revision of aseptic total knee arthroplasties. PMID:25267502

  6. Floating nut retention system

    NASA Technical Reports Server (NTRS)

    Charles, J. F.; Theakston, H. A. (Inventor)

    1980-01-01

    A floating nut retention system includes a nut with a central aperture. An inner retainer plate has an opening which is fixedly aligned with the nut aperture. An outer retainer member is formed of a base plate having an opening and a surface adjacent to a surface of the inner retainer plate. The outer retainer member includes a securing mechanism for retaining the inner retainer plate adjacent to the outer retainer member. The securing mechanism enables the inner retainer plate to float with respect to the outer retainer number, while simultaneously forming a bearing surface for inner retainer plate.

  7. Tethered float liquid level sensor

    DOEpatents

    Daily, III, William Dean

    2016-09-06

    An apparatus for sensing the level of a liquid includes a float, a tether attached to the float, a pulley attached to the tether, a rotation sensor connected to the pulley that senses vertical movement of said float and senses the level of the liquid.

  8. Compound floating pivot micromechanisms

    DOEpatents

    Garcia, Ernest J.

    2001-04-24

    A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use compound floating pivot structures to attain far greater tilt angles than are practical using other micromechanical techniques. The new mechanisms are also capable of bi-directional tilt about multiple axes.

  9. Floating platform with monolithically formed float members and platform

    SciTech Connect

    Finsterwalder, U.

    1981-06-30

    Floating platforms for various offshore facilities are formed of float members monolithically connected to a superposed platform. The float members are spherically shaped and are formed of reinforced or prestressed concrete. The platform can be a hollow planar member or it can be curved in one or two directions, and the platforms are formed of prestressed concrete. Cylindrical shafts can be used to connect the spherically shaped floats and the platform. Individual floating platforms can be connected by expansion joints and used as a runway. The float members can be constructed at the shoreline, launched into the water and held in a regular pattern while decked over with the platform. After completion of the construction procedure, the floating platform can be moved to an offshore location for use.

  10. Knee arthroscopy - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100117.htm Knee arthroscopy - series To use the sharing features on ... 5 out of 5 Normal anatomy Overview The knee is a complex joint made up of the ...

  11. Knee braces - unloading

    MedlinePlus

    ... most people talk about the arthritis in their knees, they are referring to a type of arthritis ... is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions ...

  12. Partial knee replacement - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series To use the sharing features on ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  13. Osteotomy of the knee

    MedlinePlus

    ... is not affected unless you have had a knee injury in the past. Osteotomy surgery works by shifting ... M. Editorial team. Related MedlinePlus Health Topics Arthritis Knee Injuries and Disorders Browse the Encyclopedia A.D.A. ...

  14. Knee joint replacement

    MedlinePlus

    The results of a total knee replacement are often excellent. The operation relieves pain for most people. Most people do not need help walking after they fully recover. Most artificial knee joints last 10 ...

  15. Partial knee replacement

    MedlinePlus

    Most people recover quickly and have much less pain than they did before surgery. People who have a partial knee replacement recover faster than those who have a total knee replacement. Many people are able to walk ...

  16. Knee joint replacement - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series—Normal anatomy To use the sharing ... of 4 Overview The knee is a complex joint. It contains the distal end of the femur ( ...

  17. Knee braces - unloading

    MedlinePlus

    ... is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions all of your bones and joints, lets the bones glide over one another. If ... the knee become weaker. Over time, your whole knee becomes ...

  18. Freely floating smectic films.

    PubMed

    May, Kathrin; Harth, Kirsten; Trittel, Torsten; Stannarius, Ralf

    2014-05-19

    We have investigated the dynamics of freely floating smectic bubbles using high-speed optical imaging. Bubbles in the size range from a few hundred micrometers to several centimeters were prepared from collapsing catenoids. They represent ideal model systems for the study of thin-film fluid dynamics under well-controlled conditions. Owing to the internal smectic layer structure, the bubbles combine features of both soap films and vesicles in their unique shape dynamics. From a strongly elongated initial shape after pinch-off, they relax towards the spherical equilibrium, first by a slow redistribution of the smectic layers, and finally by weak, damped shape oscillations. In addition, we describe the rupture of freely floating smectic bubbles, and the formation and stability of smectic filaments. PMID:24692347

  19. Predicting Knee Osteoarthritis.

    PubMed

    Gardiner, Bruce S; Woodhouse, Francis G; Besier, Thor F; Grodzinsky, Alan J; Lloyd, David G; Zhang, Lihai; Smith, David W

    2016-01-01

    Treatment options for osteoarthritis (OA) beyond pain relief or total knee replacement are very limited. Because of this, attention has shifted to identifying which factors increase the risk of OA in vulnerable populations in order to be able to give recommendations to delay disease onset or to slow disease progression. The gold standard is then to use principles of risk management, first to provide subject-specific estimates of risk and then to find ways of reducing that risk. Population studies of OA risk based on statistical associations do not provide such individually tailored information. Here we argue that mechanistic models of cartilage tissue maintenance and damage coupled to statistical models incorporating model uncertainty, united within the framework of structural reliability analysis, provide an avenue for bridging the disciplines of epidemiology, cell biology, genetics and biomechanics. Such models promise subject-specific OA risk assessment and personalized strategies for mitigating or even avoiding OA. We illustrate the proposed approach with a simple model of cartilage extracellular matrix synthesis and loss regulated by daily physical activity. PMID:26206679

  20. The Floating Ball Paradox

    NASA Astrophysics Data System (ADS)

    Wente, Henry C.

    2008-11-01

    In capillary theory there are two kinds of surface tension. There is the surface tension at the interface between two immiscible fluids. Thomas Young [9] also allowed for there to be a surface tension associated with a liquid-solid interface. He proceeded to use a balance of forces argument to derive the well-known contact angle condition along a liquid-liquid-solid intersection. The validity of this argument has recently been called into question by R. Finn [6]. A floating ball experiment discussed in that paper leads to an apparent paradox. We address this issue.

  1. Does It Sink or Float?

    ERIC Educational Resources Information Center

    McDonald, Judith Richards

    2012-01-01

    This activity is designed to teach prekindergarten to second grade students about the concept of sink or float through an inquiry activity. Students will use familiar objects to predict and test the properties of sink and float. Background information is offered to teachers to assist them with this activity. This lesson begins with an engaging…

  2. Floating mirror mount

    SciTech Connect

    Koop, D.E.

    1989-01-03

    This patent describes a floating mirror mount for a mirror of a laser is described consisting of: a mirror having a front surface and a back surface, a keeper encircling the mirror and having a peripheral flange engaging the front surface of the mirror when the mirror is not installed in a laser, a retainer positioned rearwardly of the back surface of the mirror and connected to the keeper and having a spring seating surface, spring means engageable with the spring seating surface of the retainer for exerting a resilient biasing force on the mirror, and fastening means for connecting the retainer to the mirror positioning structure of the laser on installation of the mirror mount in the laser.

  3. Floating Silicon Method

    SciTech Connect

    Kellerman, Peter

    2013-12-21

    The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

  4. Floating into Deep Space

    NASA Astrophysics Data System (ADS)

    La Frenais, R.; Saraceno, T.; Powell, J.

    2014-04-01

    Is it possible for spaceflight to become more sustainable? Artist and architect Tomas Saraceno proposes a long-term artscience research project based on his initial work with solar balloons to join with the efforts of engineers such as John Powell, working on the Airship to Orbit experiments, which describe a three stage process of using airships to fly to a large suborbital "Dark Sky Station' then literally floating into orbit with additional electrical and chemical propulsion. (See: http://www.jpaerospace.com) In his artworks Tomás Saraceno proposes cell-like flying cities as possible architectonic living spaces in direct reference to Buckminster Fuller's Cloud Nine (circa 1960). The fantastic architectural utopia Cloud Nine consists of a freely floating sphere measuring one mile in diameter that offers living space to several autonomous communities encompassing thousands of inhabitants each. The notion of the cloud is essential to the artist's work. The cloud as metaphor stands for artistic intention, for the meaning of territory and border in today's (urban) society, and for exploring possibilities for the sustainable development of the human living environment. In Saraceno's work this environment is not limited to the earth, but is explicitly conceived to reach into outer space. (Biomimetic Constructions- On the works of Tomás Saraceno By Katharina Schlüter) Saraceno is also interested in human factors experiments using his existing constructions as analogue environments for living on Mars and is proposing carry out a series of workshops, experiments and solar balloon launces in White Sands desert in early 2016 in collaboration with the curator Dr Rob La Frenais, the Rubin Center at The University of Texas at El Paso and various scientific partners.

  5. Preventing Knee Injuries

    MedlinePlus

    ... to tearing. Growth Plate Injuries, Fractures, and Dislocations Knee fractures rarely occur in childhood sports, but with any ... is the bump on the front of the knee where the patellar tendon attaches. Fractures to the growth plate in this area often ...

  6. Bicompartmental knee arthroplasty

    PubMed Central

    Giachino, Matteo; Risitano, Salvatore; Atzori, Francesco

    2016-01-01

    Total knee arthroplasty (TKA) is the most worldwide practiced surgery for knee osteoarthritis and its efficacy is mightily described by literature. Concerns about the invasiveness of TKA let the introduction of segmental resurfacing of the joint for younger patients with localized osteoarthritis. Bone stock sparing and ligaments preservation are the essence of both unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BKA). Advantages related to BKA are the respect of knee biomechanics, lower complications rates, shorter hospital stay, faster rehabilitation. Moreover, in case of failure of the first implant the conversion to TKA is undemanding and can be compared to a standard prosthesis. Our experience suggest that BKA is a reliable technique in selected cases and especially younger people with higher functional requests can favourably profit from it. Although those results are encouraging, we still need further prospective, randomized, long-term studies to finally assess BKA indications and outcomes. PMID:26855941

  7. Bicompartmental knee arthroplasty.

    PubMed

    Sabatini, Luigi; Giachino, Matteo; Risitano, Salvatore; Atzori, Francesco

    2016-01-01

    Total knee arthroplasty (TKA) is the most worldwide practiced surgery for knee osteoarthritis and its efficacy is mightily described by literature. Concerns about the invasiveness of TKA let the introduction of segmental resurfacing of the joint for younger patients with localized osteoarthritis. Bone stock sparing and ligaments preservation are the essence of both unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BKA). Advantages related to BKA are the respect of knee biomechanics, lower complications rates, shorter hospital stay, faster rehabilitation. Moreover, in case of failure of the first implant the conversion to TKA is undemanding and can be compared to a standard prosthesis. Our experience suggest that BKA is a reliable technique in selected cases and especially younger people with higher functional requests can favourably profit from it. Although those results are encouraging, we still need further prospective, randomized, long-term studies to finally assess BKA indications and outcomes. PMID:26855941

  8. Treating Osteoarthritis of the Knee

    MedlinePlus

    ... osteotomy may need knee replacement surgery in the future. Arthroplasty is also called joint or knee replacement therapy. A surgeon removes the part of the knee damaged by osteoarthritis and replaces it with an artificial joint made from metals and plastic. All or part of the knee joint may ...

  9. Floating orbital molecular dynamics simulations.

    PubMed

    Perlt, Eva; Brüssel, Marc; Kirchner, Barbara

    2014-04-21

    We introduce an alternative ab initio molecular dynamics simulation as a unification of Hartree-Fock molecular dynamics and the floating orbital approach. The general scheme of the floating orbital molecular dynamics method is presented. Moreover, a simple but sophisticated guess for the orbital centers is provided to reduce the number of electronic structure optimization steps at each molecular dynamics step. The conservation of total energy and angular momentum is investigated in order to validate the floating orbital molecular dynamics approach with and without application of the initial guess. Finally, a water monomer and a water dimer are simulated, and the influence of the orbital floating on certain properties like the dipole moment is investigated. PMID:24600690

  10. NULL convention floating point multiplier.

    PubMed

    Albert, Anitha Juliette; Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation. PMID:25879069

  11. NULL Convention Floating Point Multiplier

    PubMed Central

    Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation. PMID:25879069

  12. Electrically floating, near vertical incidence, skywave antenna

    SciTech Connect

    Anderson, Allen A.; Kaser, Timothy G.; Tremblay, Paul A.; Mays, Belva L.

    2014-07-08

    An Electrically Floating, Near Vertical Incidence, Skywave (NVIS) Antenna comprising an antenna element, a floating ground element, and a grounding element. At least part of said floating ground element is positioned between said antenna element and said grounding element. The antenna is separated from the floating ground element and the grounding element by one or more electrical insulators. The floating ground element is separated from said antenna and said grounding element by one or more electrical insulators.

  13. Skylab floating ice experiment

    NASA Technical Reports Server (NTRS)

    Campbell, W. J. (Principal Investigator); Ramseier, R. O.; Weaver, R. J.; Weeks, W. F.

    1975-01-01

    The author has identified the following significant results. Coupling of the aircraft data with the ground truth observations proved to be highly successful with interesting results being obtained with IR and SLAR passive microwave techniques, and standard photography. Of particular interest were the results of the PMIS system which operated at 10.69 GHz with both vertical and horizontal polarizations. This was the first time that dual polarized images were obtained from floating ice. In both sea and lake ice, it was possible to distinguish a wide variety of thin ice types because of their large differences in brightness temperatures. It was found that the higher brightness temperature was invariably obtained in the vertically polarized mode, and as the age of the ice increases the brightness temperature increases in both polarizations. Associated with this change in age, the difference in temperature was observed as the different polarizations decreased. It appears that the horizontally polarized data is the most sensitive to variations in ice type for both fresh water and sea ice. The study also showed the great amount of information on ice surface roughness and deformation patterns that can be obtained from X-band SLAR observations.

  14. Floating wind turbine system

    NASA Technical Reports Server (NTRS)

    Viterna, Larry A. (Inventor)

    2009-01-01

    A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips. This large clearance facilitates the use of articulated rotor hubs to reduced damaging structural dynamic loads. Major components of the turbine can be assembled at the shore and transported to an offshore installation site.

  15. Impact on floating membranes

    NASA Astrophysics Data System (ADS)

    Vandenberghe, Nicolas; Duchemin, Laurent

    2016-05-01

    When impacted by a rigid body, a thin elastic membrane with negligible bending rigidity floating on a liquid pool deforms. Two axisymmetric waves radiating from the impact point propagate. First, a longitudinal wave front, associated with in-plane deformation of the membrane and traveling at constant speed, separates an outward stress-free domain from a stretched domain. Then, in the stretched domain a dispersive transverse wave travels at a speed that depends on the local stretching rate. The dynamics is found to be self-similar in time. Using this property, we show that the wave dynamics is similar to the capillary waves that propagate at a liquid-gas interface but with a surface tension coefficient that depends on impact speed. During wave propagation, we observe the development of a buckling instability that gives rise to radial wrinkles. We address the dynamics of this fluid-body system, including the rapid deceleration of an impactor of finite mass, an issue that may have applications in the domain of absorption of impact energy.

  16. Floating into Thin Air

    SciTech Connect

    Hazi, A U

    2007-02-06

    On May 18, 2005, a giant helium balloon carrying the High Energy Focusing Telescope (HEFT) sailed into the spring sky over the deserts of New Mexico. The spindly steel and aluminum gondola that houses the optics, detectors, and other components of the telescope floated for 25 hours after its launch from Fort Sumner, New Mexico. For 21 of those hours, the balloon was nearly 40 kilometers above Earth's surface--almost four times higher than the altitude routinely flown by commercial jet aircraft. In the upper reaches of Earth's atmosphere, HEFT searched the universe for x-ray sources from highly energetic objects such as binary stars, galaxy clusters, and supermassive black holes. Before landing in Arizona, the telescope observed and imaged a dozen scientific targets by capturing photons emitted from these objects in the high-energy (hard) x-ray range (above 10 kiloelectronvolts). Among these targets were the Crab synchrotron nebula, the black hole Cygnus X-1 (one of the brightest x-ray sources in the sky), and the blazar 3C454.3. The scientific data gathered from these targets are among the first focused hard x-ray images returned from high altitudes.

  17. Advanced concepts in knee arthrodesis

    PubMed Central

    Wood, Jennifer H; Conway, Janet D

    2015-01-01

    The aim is to describe advanced strategies that can be used to diagnose and treat complications after knee arthrodesis and to describe temporary knee arthrodesis to treat infected knee arthroplasty. Potential difficult complications include nonunited knee arthrodesis, limb length discrepancy after knee arthrodesis, and united but infected knee arthrodesis. If a nonunited knee arthrodesis shows evidence of implant loosening or failure, then bone grafting the nonunion site as well as exchange intramedullary nailing and/or supplemental plate fixation are recommended. If symptomatic limb length discrepancy cannot be satisfactorily treated with a shoe lift, then the patient should undergo tibial lengthening over nail with a monolateral fixator or exchange nailing with a femoral internal lengthening device. If a united knee arthrodesis is infected, the nail must be removed. Then the surgeon has the option of replacing it with a long, antibiotic cement-coated nail. The authors also describe temporary knee arthrodesis for infected knee arthroplasty in patients who have the potential to undergo insertion of a new implant. The procedure has two goals: eradication of infection and stabilization of the knee. A temporary knee fusion can be accomplished by inserting both an antibiotic cement-coated knee fusion nail and a static antibiotic cement-coated spacer. These advanced techniques can be helpful when treating difficult complications after knee arthrodesis and treating cases of infected knee arthroplasty. PMID:25793160

  18. Knee MRI scan

    MedlinePlus

    ... magnetic resonance imaging) scan uses energy from strong magnets to create pictures of the knee joint and ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  19. Anterior knee pain

    MedlinePlus

    ... places extra stress on the kneecap (such as running, jumping or twisting, skiing, or playing soccer). You ... noticeable with: Deep knee bends Going down stairs Running downhill Standing up after sitting for awhile

  20. Total Knee Replacement

    MedlinePlus

    ... as anti- inflammatory medications, cortisone injections, lubricating injections, physical therapy, or other surgeries A knee that has become ... your function. Other treatment options — including medications, injections, physical therapy, or other types of surgery — will also be ...

  1. Tourniquetless Total Knee Arthroplasty

    MedlinePlus Videos and Cool Tools

    Tourniquetless Total Knee Arthroplasty You must have Javascript enabled in your web browser. View Program Transcript Click Here to view the OR-Live, Inc. Privacy Policy and Legal Notice © 2010 OR- ...

  2. Knee arthroscopy - discharge

    MedlinePlus

    ... is cartilage that cushions the space between the bones in the knee. Surgery is done to repair or remove it. Torn or damaged anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) Inflamed or damaged lining of the joint. This ...

  3. Knee arthroscopy - discharge

    MedlinePlus

    ... knee arthroscopy). You may have been checked for: Torn meniscus. Meniscus is cartilage that cushions the space ... Surgery is done to repair or remove it. Torn or damaged anterior cruciate ligament (ACL) or posterior ...

  4. Taking care of your new knee joint

    MedlinePlus

    Knee arthroplasty - precautions; Knee replacement - precautions ... After you have knee replacement surgery , you will need to be careful about how you move your knee, especially for the first few months after ...

  5. The epidemiology of revision total knee and hip arthroplasty in England and Wales: a comparative analysis with projections for the United States. A study using the National Joint Registry dataset.

    PubMed

    Patel, A; Pavlou, G; Mújica-Mota, R E; Toms, A D

    2015-08-01

    Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are recognised and proven interventions for patients with advanced arthritis. Studies to date have demonstrated a steady increase in the requirement for primary and revision procedures. Projected estimates made for the United States show that by 2030 the demand for primary TKA will grow by 673% and for revision TKA by 601% from the level in 2005. For THA the projected estimates are 174% and 137% for primary and revision surgery, respectively. The purpose of this study was to see if those predictions were similar for England and Wales using data from the National Joint Registry and the Office of National Statistics. Analysis of data for England and Wales suggest that by 2030, the volume of primary and revision TKAs will have increased by 117% and 332%, respectively between 2012 and 2030. The data for the United States translates to a 306% cumulative rate of increase between 2012 and 2030 for revision surgery, which is similar to our predictions for England and Wales. The predictions from the United States for primary TKA were similar to our upper limit projections. For THA, we predicted an increase of 134% and 31% for primary and revision hip surgery, respectively. Our model has limitations, however, it highlights the economic burden of arthroplasty in the future in England and Wales as a real and unaddressed problem. This will have significant implications for the provision of health care and the management of orthopaedic services in the future. PMID:26224824

  6. Reading Knee-Deep

    ERIC Educational Resources Information Center

    Jewett, Pamela

    2007-01-01

    Freire told his audience at a seminar at the University of Massachusetts, "You need to read knee-deep in texts, for deeper than surface meanings, and you need to know the words to be able to do it" (quoted in Cleary, 2003). In a children's literature class, fifteen teachers and I traveled along a path that moved us toward reading knee-deep as we…

  7. Dashboard (in the) knee.

    PubMed

    Patel, M S; Qureshi, A A; Green, T P

    2015-03-01

    We present the case of a 19-year-old individual presenting to an orthopaedic outpatient clinic several months following a dashboard knee injury during a road traffic accident with intermittent mechanical symptoms. Despite unremarkable examination findings and normal magnetic resonance imaging, the patient was identified subsequently as having an intra-articular plastic foreign body consistent with a piece of dashboard on arthroscopic knee assessment, the retrieval of which resulted in a complete resolution of symptoms. PMID:25723676

  8. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 15 2011-07-01 2011-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  9. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 16 2014-07-01 2014-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  10. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 16 2012-07-01 2012-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  11. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  12. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 16 2013-07-01 2013-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  13. Endodontic Epidemiology

    PubMed Central

    Shahravan, Arash; Haghdoost, Ali Akbar

    2014-01-01

    Epidemiology is the study of disease distribution and factors determining or affecting it. Likewise, endodontic epidemiology can be defined as the science of studying the distribution pattern and determinants of pulp and periapical diseases; specially apical periodontitis. Although different study designs have been used in endodontics, researchers must pay more attention to study designs with higher level of evidence such as randomized clinical trials. PMID:24688577

  14. Designing seaplane hulls and floats

    NASA Technical Reports Server (NTRS)

    Benoit,

    1926-01-01

    Experimental data, such as the results of tank tests of models, render it possible to predict, at least in principle, as to how a hull or float of a given shape will comport itself. We will see further along, however, how uncertain these methods are and how they leave room for empiricism, which will reign for a long time yet in seaplane research bureaus.

  15. Flinking: Neither Floating nor Sinking.

    ERIC Educational Resources Information Center

    Wilson, Roger B.

    1993-01-01

    Describes an activity that challenges students to make an object that, when released under water, does not float up or sink down. The main concept this activity investigates is the density of ordinary objects in comparison to the density of water. (PR)

  16. Cementless total knee arthroplasty

    PubMed Central

    Risitano, Salvatore; Sabatini, Luigi; Giachino, Matteo; Agati, Gabriele; Massè, Alessandro

    2016-01-01

    Interest for uncemented total knee arthroplasty (TKA) has greatly increased in recent years. This technique, less used than cemented knee replacement in the last decades, sees a revival thanks an advance in prosthetic design, instrumentation and operative technique. The related literature in some cases shows conflicting data on survival and on the revision’s rate, but in most cases a success rate comparable to cemented TKA is reported. The optimal fixation in TKA is a subject of debate with the majority of surgeons favouring cemented fixation. PMID:27162779

  17. Hypermobility and Knee Injuries.

    ERIC Educational Resources Information Center

    Steiner, Mark E.

    1987-01-01

    A review of research on the effect of hypermobility on knee injury indicates that greater than normal joint flexibility may be necessary for some athletic endeavors and that it may be possible to change one's underlying flexibility through training. However, for most athletes, inherited flexibility probably plays only a small role, if any, in…

  18. [Occupational epidemiology].

    PubMed

    Ahrens, W; Behrens, T; Mester, B; Schmeisser, N

    2008-03-01

    The aim of occupational epidemiology is to describe workplace-related diseases and to identify their underlying causes. Its primary goal is to protect workers from hazardous effects of the working process by applying work-related primary and secondary prevention measures. To assess health risks different study designs and a wide array of complex study instruments and methods are frequently employed that cannot be replaced by toxicological investigations. This paper primarily addresses health risks by agent exposures. In this context a central task of occupational epidemiology is careful assessment of exposure. Different data sources, such as work site measurements, register data, archive material, experts' opinion, and the workers' personal estimates of exposure may be used during this process. In addition, biological markers can complement exposure assessment. Since thorough occupational epidemiologic studies allow assessment of disease risks under realistic exposure conditions, their results should be more frequently used to derive workplace-related threshold limit values. PMID:18311483

  19. Polygenic Epidemiology

    PubMed Central

    2016-01-01

    ABSTRACT Much of the genetic basis of complex traits is present on current genotyping products, but the individual variants that affect the traits have largely not been identified. Several traditional problems in genetic epidemiology have recently been addressed by assuming a polygenic basis for disease and treating it as a single entity. Here I briefly review some of these applications, which collectively may be termed polygenic epidemiology. Methodologies in this area include polygenic scoring, linear mixed models, and linkage disequilibrium scoring. They have been used to establish a polygenic effect, estimate genetic correlation between traits, estimate how many variants affect a trait, stratify cases into subphenotypes, predict individual disease risks, and infer causal effects using Mendelian randomization. Polygenic epidemiology will continue to yield useful applications even while much of the specific variation underlying complex traits remains undiscovered. PMID:27061411

  20. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  1. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.136... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly (refer to §§ 572.130(a)(1)(v) and (vi)) for the purpose of...

  2. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  3. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.126...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly is part of the leg assembly (drawing 127-4000-1 and -2). (b) When the...

  4. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  5. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure. 572.136... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly (refer to §§ 572.130(a)(1)(v) and (vi)) for the purpose of...

  6. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  7. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.126...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly is part of the leg assembly (drawing 127-4000-1 and -2). (b) When the...

  8. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  9. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Knees and knee impact test procedure. 572.126...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly is part of the leg assembly (drawing 127-4000-1 and -2). (b) When the...

  10. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.136... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly (refer to §§ 572.130(a)(1)(v) and (vi)) for the purpose of...

  11. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure. 572.126...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly is part of the leg assembly (drawing 127-4000-1 and -2). (b) When the...

  12. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.126...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly is part of the leg assembly (drawing 127-4000-1 and -2). (b) When the...

  13. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  14. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.136... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly (refer to §§ 572.130(a)(1)(v) and (vi)) for the purpose of...

  15. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  16. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  17. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Knees and knee impact test procedure. 572.136... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure. (a) Knee assembly. The knee assembly (refer to §§ 572.130(a)(1)(v) and (vi)) for the purpose of...

  18. Cognitive epidemiology

    PubMed Central

    Deary, Ian J; Batty, G David

    2007-01-01

    This glossary provides a guide to some concepts, findings and issues of discussion in the new field of research in which intelligence test scores are associated with mortality and morbidity. Intelligence tests are devised and studied by differential psychologists. Some of the major concepts in differential psychology are explained, especially those regarding cognitive ability testing. Some aspects of IQ (intelligence) tests are described and some of the major tests are outlined. A short guide is given to the main statistical techniques used by differential psychologists in the study of human mental abilities. There is a discussion of common epidemiological concepts in the context of cognitive epidemiology. PMID:17435201

  19. Can flexibility help you float?

    NASA Astrophysics Data System (ADS)

    Burton, L. J.; Bush, J. W. M.

    2012-10-01

    We consider the role of flexibility in the weight-bearing characteristics of bodies floating at an interface. Specifically, we develop a theoretical model for a two-dimensional thin floating plate that yields the maximum stable plate load and optimal stiffness for weight support. Plates small relative to the capillary length are primarily supported by surface tension, and their weight-bearing potential does not benefit from flexibility. Above a critical size comparable to the capillary length, flexibility assists interfacial flotation. For plates on the order of and larger than the capillary length, deflection from an initially flat shape increases the force resulting from hydrostatic pressure, allowing the plate to support a greater load. In this large plate limit, the shape that bears the most weight is a semicircle, which displaces the most fluid above the plate for a fixed plate length. Exact results for maximum weight-bearing plate shapes are compared to analytic approximations made in the limits of large and small plate sizes. The value of flexibility for floating to a number of biological organisms is discussed in light of our study.

  20. Instability of floating extensional flows

    NASA Astrophysics Data System (ADS)

    Sayag, Roiy; Worster, Grae

    2015-11-01

    We study the propagation of a viscous fluid over a thin layer of a denser and inviscid fluid. The viscous fluid is released axisymmetrially at constant flux, and is driven by gravity. Near the origin, where the viscous layer is thick, the flow is dominated by vertical shear. In the outer region where the viscous layer is thinner, it floats over the inviscid layer and the dominant stress is extensional. The floating region of such flows remains axisymmetric when the viscous fluid is Newtonian. In contrast, when the viscous fluid is non Newtonian, the floating region can be distributed in an array of extensional tongues. We use experimental and theoretical analysis to study the symmetry breaking of the extensional region. Experiments using polymeric fluids show that the characteristic wavelength of the tongues increases with flux. Theoretically, we model the symmetry breaking as flow instability of a power-law fluid that becomes Newtonian at low strain rates. Our model predicts unstable modes at the strongly non-Newtonian limit, and stable, axisymmetric mode in the Newtonian limit.

  1. Dragging a floating horizontal cylinder

    NASA Astrophysics Data System (ADS)

    Lee, Duck-Gyu; Kim, Ho-Young

    2010-11-01

    A cylinder immersed in a fluid stream experiences a drag, and it is well known that the drag coefficient is a function of the Reynolds number only. Here we study the force exerted on a long horizontal cylinder that is dragged perpendicular to its axis while floating on an air-water interface with a high Reynolds number. In addition to the flow-induced drag, the floating body is subjected to capillary forces along the contact line where the three phases of liquid/solid/gas meet. We first theoretically predict the meniscus profile around the horizontally moving cylinder assuming the potential flow, and show that the profile is in good agreement with that obtained experimentally. Then we compare our theoretical predictions and experimental measurement results for the drag coefficient of a floating horizontal cylinder that is given by a function of the Weber number and the Bond number. This study can help us to understand the horizontal motion of partially submerged objects at air-liquid interface, such as semi-aquatic insects and marine plants.

  2. Float zone experiments in space

    NASA Technical Reports Server (NTRS)

    Verhoeven, J. D.; Noack, M. A.; Gill, W. N.; Hau, C. C.

    1984-01-01

    The molten zone/freezing crystal interface system and all the mechanisms were examined. If Marangoni convection produces oscillatory flows in the float zone of semiconductor materials, such as silicon, then it is unlikely that superior quality crystals can be grown in space using this process. The major goals were: (1) to determine the conditions for the onset of Marangoni flows in molten tin, a model system for low Prandtl number molten semiconductor materials; (2) to determine whether the flows can be suppressed by a thin oxide layer; and (3) based on experimental and mathematical analysis, to predict whether oscillatory flows will occur in the float zone silicon geometry in space, and if so, could it be suppressed by thin oxide or nitride films. Techniques were developed to analyze molten tin surfaces in a UHV system in a disk float zone geometry to minimize buoyancy flows. The critical Marangoni number for onset of oscillatory flows was determined to be greater than 4300 on atomically clean molten tin surfaces.

  3. Spontaneous Knee Ankylosis through Heterotopic Ossification after Total Knee Arthroplasty

    PubMed Central

    Boulezaz, Samuel; Gibon, Emmanuel; Loriaut, Philippe; Casabianca, Laurent; Rousseau, Romain; Dallaudiere, Benjamin; Pascal-Moussellard, Hugues

    2016-01-01

    This paper reports on a case of total ankylosis of the knee after a cruciate-sacrificing cemented total knee arthroplasty (TKA). An 82-year-old female patient previously underwent primary TKA for osteoarthritis twenty years ago in our institution. She had recovered uneventfully and returned to her regular activities. There was no history of postsurgical trauma; however, she progressively lost knee range of motion. Radiographs revealed severe bridging heterotopic ossification. PMID:27119034

  4. Nutritional Epidemiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although observations on relationships between diet and health have always been recognized—the systematic science of nutritional epidemiology in populations is relatively recent. Important observations propelling the field of nutrition forward were numerous in the 18th and 19th centuries, as it was...

  5. Epidemiological causality.

    PubMed

    Morabia, Alfredo

    2005-01-01

    Epidemiological methods, which combine population thinking and group comparisons, can primarily identify causes of disease in populations. There is therefore a tension between our intuitive notion of a cause, which we want to be deterministic and invariant at the individual level, and the epidemiological notion of causes, which are invariant only at the population level. Epidemiologists have given heretofore a pragmatic solution to this tension. Causal inference in epidemiology consists in checking the logical coherence of a causality statement and determining whether what has been found grossly contradicts what we think we already know: how strong is the association? Is there a dose-response relationship? Does the cause precede the effect? Is the effect biologically plausible? Etc. This approach to causal inference can be traced back to the English philosophers David Hume and John Stuart Mill. On the other hand, the mode of establishing causality, devised by Jakob Henle and Robert Koch, which has been fruitful in bacteriology, requires that in every instance the effect invariably follows the cause (e.g., inoculation of Koch bacillus and tuberculosis). This is incompatible with epidemiological causality which has to deal with probabilistic effects (e.g., smoking and lung cancer), and is therefore invariant only for the population. PMID:16898206

  6. 14 CFR 27.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float design. 27.753 Section 27.753... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.753 Main float design. (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure...

  7. 14 CFR 29.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float design. 29.753 Section 29.753... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.753 Main float design. (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure...

  8. 14 CFR 29.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 29.753 Section 29.753 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.753 Main float design. (a) Bag floats. Each bag float...

  9. 14 CFR 27.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 27.753 Section 27.753... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.753 Main float design. (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure...

  10. Tank Tests of Twin Seaplane Floats

    NASA Technical Reports Server (NTRS)

    Herrman, H; Kempf, G; Kloess, H

    1928-01-01

    The following report contains the most essential data for the hydrodynamic portion of the twin-float problem. The following points were successfully investigated: 1) difference between stationary and nonstationary flow; 2) effect of the shape of the step; 3) effect of distance between floats; 4) effect of nose-heavy and tail-heavy moments; 5) effect of the shape of floats; 6) maneuverability.

  11. Synovial plicae of the knee

    SciTech Connect

    Apple, J.S.; Martinez, S.; Daffner, R.H.; Gehweiler, J.A.; Hardaker, W.T.

    1982-01-01

    This report describes the anatomy, patho-physiology, clinical, and radiographic findings, and treatment of the synovial plicae of the knee joint. The suprapatellar plica is a synovial fold present in the suprapatellar pouch of the knee joint in approximately 20% of the population. This fold may become symptomatic after injury and cause symptoms similar to other common internal derangements of the knee. Double contrast arthrography of the knee can be used to identify the presence of plicae. Although arthrography can identify the presence of a plica, its clinical significance requires close correlation with symptoms and an accurate clinical examination.

  12. Multiligamentous injuries and knee dislocations.

    PubMed

    Gimber, Lana H; Scalcione, Luke R; Rowan, Andrew; Hardy, Jolene C; Melville, David M; Taljanovic, Mihra S

    2015-11-01

    Complex capsular ligamentous structures contribute to stability of the knee joint. Simultaneous injury of two or more knee ligaments, aside from concurrent tears involving the anterior cruciate and medial collateral ligaments, is considered to be associated with femorotibial knee dislocations. Proximal tibiofibular joint dislocations are not always easily recognized and may be overlooked or missed. Patellofemoral dislocations can be transient with MR imaging sometimes required to reach the diagnosis. In this article, the authors describe the mechanism of injury, ligamentous disruptions, imaging, and treatment options of various types of knee dislocations including injuries of the femorotibial, proximal tibiofibular, and patellofemoral joints. PMID:26002747

  13. Modeling International Space Station (ISS) Floating Potentials

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.; Gardner, Barbara

    2002-01-01

    The floating potential of the International Space Station (ISS) as a function of the electron current collection of its high voltage solar array panels is derived analytically. Based on Floating Potential Probe (FPP) measurements of the ISS potential and ambient plasma characteristics, it is shown that the ISS floating potential is a strong function of the electron temperature of the surrounding plasma. While the ISS floating potential has so far not attained the pre-flight predicted highly negative values, it is shown that for future mission builds, ISS must continue to provide two-fault tolerant arc-hazard protection for astronauts on EVA.

  14. Knee stabilization in patients with medial compartment knee osteoarthritis

    PubMed Central

    Lewek, Michael D.; Ramsey, Dan K.; Snyder-Mackler, Lynn; Rudolph, Katherine S.

    2005-01-01

    OBJECTIVE Individuals with medial knee osteoarthritis (MKOA) experience knee laxity and instability. Muscle stabilization strategies may influence the long term integrity of the joint. In this study we determined how individuals with medial knee OA respond to a rapid valgus knee movement to investigate the relationship between muscle stabilization strategies and knee instability. METHODS Twenty one subjects with MKOA and genu varum, and 19 control subjects were tested. Subjects stood with the test limb on a moveable platform that translated laterally to rapidly stress the knee’s medial periarticular structures and create a potentially destabilizing feeling at the knee joint. Knee motion and muscle responses were recorded. Subjects rated their knee instability with a self-report questionnaire about knee instability during daily activities. RESULTS Prior to plate movement the OA subjects demonstrated more medial muscle co-contraction (p=0.014). Following plate movement the OA subjects shifted less weight off the test limb (p = 0.013) and had more medial co-contraction (p=0.037). Those without instability had higher VMMH co-contraction than those who reported more instability (p=0.038). Knee stability correlated positively with VMMH co-contraction prior to plate movement (r = 0.459; p = 0.042). CONCLUSION This study demonstrates that individuals with MKOA attempt to stabilize the knee with greater medial muscle co-contraction in response to laxity that appears on only the medial side of the joint. This strategy presumably contributes to higher joint compression and could exacerbate joint destruction and needs to be altered to slow or stop the progression of the OA disease process. PMID:16142714

  15. Selectively Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    Myers, W. Neill (Inventor); Shadoan, Michael D. (Inventor); Forbes, John C. (Inventor); Baker, Kevin J. (Inventor); Rice, Darron C. (Inventor)

    1996-01-01

    A knee brace for aiding in rehabilitation of damaged leg muscles includes upper and lower housings normally pivotable one relative to the other about the knee joint axis of a patient. The upper housing is attachable to the thigh of the patient above the knee joint while the lower housing is secured to a stirrup which extends downwardly along the patient's leg and is attached to the patient's shoe. An actuation rod is carried within the lower housing and is coupled to a cable. The upper and lower housings carry cooperative clutch/brake elements which normally are disengaged to permit relative movement between the upper and lower housings. When the cable is extended the clutch/brake elements engage and lock the housings together. A heel strike mechanism fastened to the stirrup and the heel of the shoe is connected to the cable to selectively extend the cable and lock the brace in substantially any position when the patient places weight on the heel.

  16. Selectively lockable knee brace

    NASA Technical Reports Server (NTRS)

    Myers, Neill (Inventor); Shadoan, Mike (Inventor); Forbes, John (Inventor); Baker, Kevin (Inventor)

    1994-01-01

    A knee brace for aiding in rehabilitation of damaged leg muscles includes upper and lower housings, normally pivotable, one relative to the other about the knee joint axis of a patient. The upper housing is attachable to the thigh of the patient above the knee joint, while the lower housing is secured to a stirrup which extends downwardly along the patient's leg and is attached to the patient's shoe. An actuation rod is carried within the lower housing and is coupled to a cable. The upper and lower housings carry cooperative clutch/brake elements which normally are disengaged to permit relative movement between the upper and lower housings. When the cable is extended, the clutch/brake elements engage and lock the housings together. A heel strike mechanism fastened to the stirrup and the heel of the shoe is connected to the cable to selectively extend the cable and lock the brace in substantially any position when the patient places weight on the heel.

  17. Digital Epidemiology

    PubMed Central

    Salathé, Marcel; Bengtsson, Linus; Bodnar, Todd J.; Brewer, Devon D.; Brownstein, John S.; Buckee, Caroline; Campbell, Ellsworth M.; Cattuto, Ciro; Khandelwal, Shashank; Mabry, Patricia L.; Vespignani, Alessandro

    2012-01-01

    Mobile, social, real-time: the ongoing revolution in the way people communicate has given rise to a new kind of epidemiology. Digital data sources, when harnessed appropriately, can provide local and timely information about disease and health dynamics in populations around the world. The rapid, unprecedented increase in the availability of relevant data from various digital sources creates considerable technical and computational challenges. PMID:22844241

  18. Wave drag on floating bodies

    PubMed Central

    Le Merrer, Marie; Clanet, Christophe; Quéré, David; Raphaël, Élie; Chevy, Frédéric

    2011-01-01

    We measure the deceleration of liquid nitrogen drops floating at the surface of a liquid bath. On water, the friction force is found to be about 10 to 100 times larger than on a solid substrate, which is shown to arise from wave resistance. We investigate the influence of the bath viscosity and show that the dissipation decreases as the viscosity is increased, owing to wave damping. The measured resistance is well predicted by a model imposing a vertical force (i.e., the drop weight) on a finite area, as long as the wake can be considered stationary. PMID:21876186

  19. Floating platform well production apparatus

    SciTech Connect

    Nobileau, P.C.

    1980-10-21

    A plurality of wells are clustered around a central riser which is maintained under tension from a floating platform. A plurality of spiders on the riser carry funnels in vertical alignment with the wells. The funnels are sufficiently large to permit the passage of wellhead connectors and master block valves, and the production risers include centralizers which brace the production riser from the funnels through a limited vertical range. Tensioning of the production riser is with a lower force and through a limited range which precludes disengagement of the centralizers from the funnel. Some centralizers are located to facilitate entry and attachment to the wellhead.

  20. Floating liquid bridge charge dynamics

    NASA Astrophysics Data System (ADS)

    Teschke, Omar; Soares, David Mendez; Gomes, Whyllerson Evaristo; Valente Filho, Juracyr Ferraz

    2016-01-01

    The interaction of liquid with electric fields is investigated in a configuration where up to 13 kV are applied between electrodes resulting in a 106 V/m electric field in the capillaries and where there is the formation of a free-standing fluid bridge in the interelectrode gap. The Mott-Gurney equation was fitted to the measured ionization current vs applied voltage curve which indicates that the ionization rate at the high-voltage anode electrode dimethylsulfoxide (DMSO) interface and space charging in the interelectrode gap determine the floating liquid bridge current for a given cathode-to-anode voltage. Space charge effects were measured in the cathode becker and also at the liquid bridge since the ionized charges at the anode migrate to the bridge outer surface and decrease the interfacial tension from 43 mJ/m2 to 29 mJ/m2. Two distinct structural regions then form the bridge, a charged plastic (bulk modulus ˜100 MPa) conducting outer layer with a surface conductivity of ˜10-9 Ω-1, which shapes and supports the floating fluid structure, and an inner liquid cylinder, where DMSO molecules flow.

  1. Automatic locking orthotic knee device

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (Inventor)

    1993-01-01

    An articulated tang in clevis joint for incorporation in newly manufactured conventional strap-on orthotic knee devices or for replacing such joints in conventional strap-on orthotic knee devices is discussed. The instant tang in clevis joint allows the user the freedom to extend and bend the knee normally when no load (weight) is applied to the knee and to automatically lock the knee when the user transfers weight to the knee, thus preventing a damaged knee from bending uncontrollably when weight is applied to the knee. The tang in clevis joint of the present invention includes first and second clevis plates, a tang assembly and a spacer plate secured between the clevis plates. Each clevis plate includes a bevelled serrated upper section. A bevelled shoe is secured to the tank in close proximity to the bevelled serrated upper section of the clevis plates. A coiled spring mounted within an oblong bore of the tang normally urges the shoes secured to the tang out of engagement with the serrated upper section of each clevic plate to allow rotation of the tang relative to the clevis plate. When weight is applied to the joint, the load compresses the coiled spring, the serrations on each clevis plate dig into the bevelled shoes secured to the tang to prevent relative movement between the tang and clevis plates. A shoulder is provided on the tang and the spacer plate to prevent overextension of the joint.

  2. Exercise and the Knee Joint.

    ERIC Educational Resources Information Center

    Clarke, H. Harrison, Ed.

    1976-01-01

    This report by the President's Council on Physical Fitness and Sports examines the effects of various forms of physical exercise on the knee joint which, because of its vulnerability, is especially subject to injury. Discussion centers around the physical characteristics of the joint, commonly used measurements for determining knee stability,…

  3. New Generation Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A knee brace that uses Space Shuttle propulsion technology has moved a step closer to being available to help knee injury and stroke patients and may possibly benefit patients with birth defects, spinal cord injuries, and post-polio conditions. After years of hard work, inventors at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, have turned over the final design and prototype to industry partners at Horton's Orthotic Lab in Little Rock, Arkansas for further clinical testing. The device, called the Selectively Lockable Knee Brace, may mean faster, less painful rehabilitation for patients by allowing the knee to move when weight is not on the heel. Devices currently on the market lock the knee in a rigid, straight-leg position, or allow continuous free motion. Pictured here is a knee brace prototype being tested and fitted at Horton's Orthotic Lab. The knee brace is just one example of how space technology is being used to improve the lives of people on Earth. NASA's MSFC inventors Michael Shadoan and Neill Myers are space propulsion engineers who use the same mechanisms and materials to build systems for rockets that they used to design and develop the knee brace.

  4. Future float zone development in industry

    NASA Technical Reports Server (NTRS)

    Sandfort, R. M.

    1980-01-01

    The present industrial requirements for float zone silicon are summarized. Developments desired by the industry in the future are reported. The five most significant problems faced today by the float zone crystal growth method in industry are discussed. They are economic, large diameter, resistivity uniformity, control of carbon, and swirl defects.

  5. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  6. Whatever Floats Your Boat: A Design Challenge

    ERIC Educational Resources Information Center

    Kornoelje, Joanne; Roman, Harry T.

    2012-01-01

    This article presents a simple design challenge, based on the PBS program "Design Squad's" "Watercraft" activity that will prove engaging to most technology and engineering students. In this floating boat challenge, students are to build a boat that can float and support 25 pennies for at least 10 seconds--without leaking, sinking, or tipping…

  7. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  8. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  9. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  10. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  11. Vertical pump with free floating check valve

    DOEpatents

    Lindsay, Malcolm

    1980-01-01

    A vertical pump with a bottom discharge having a free floating check valve isposed in the outlet plenum thereof. The free floating check valve comprises a spherical member with a hemispherical cage-like member attached thereto which is capable of allowing forward or reverse flow under appropriate conditions while preventing reverse flow under inappropriate conditions.

  12. 49 CFR 572.176 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.176... Hybrid III 10-Year-Old Child Test Dummy (HIII-10C) § 572.176 Knees and knee impact test procedure. (a) The knee assembly for the purpose of this test is the part of the leg assembly shown in drawing...

  13. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N). ... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure....

  14. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N). ... 49 Transportation 7 2011-10-01 2011-10-01 false Knees and knee impact test procedure....

  15. 49 CFR 572.176 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.176... Hybrid III 10-Year-Old Child Test Dummy (HIII-10C) § 572.176 Knees and knee impact test procedure. (a) The knee assembly for the purpose of this test is the part of the leg assembly shown in drawing...

  16. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  17. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N). ... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure....

  18. 49 CFR 572.176 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.176... Hybrid III 10-Year-Old Child Test Dummy (HIII-10C) § 572.176 Knees and knee impact test procedure. (a) The knee assembly for the purpose of this test is the part of the leg assembly shown in drawing...

  19. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  20. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N). ... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure....

  1. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  2. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N). ... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure....

  3. Floating plant dominance as a stable state

    PubMed Central

    Scheffer, Marten; Szabó, Sándor; Gragnani, Alessandra; van Nes, Egbert H.; Rinaldi, Sergio; Kautsky, Nils; Norberg, Jon; Roijackers, Rudi M. M.; Franken, Rob J. M.

    2003-01-01

    Invasion by mats of free-floating plants is among the most important threats to the functioning and biodiversity of freshwater ecosystems ranging from temperate ponds and ditches to tropical lakes. Dark, anoxic conditions under thick floating-plant cover leave little opportunity for animal or plant life, and they can have large negative impacts on fisheries and navigation in tropical lakes. Here, we demonstrate that floating-plant dominance can be a self-stabilizing ecosystem state, which may explain its notorious persistence in many situations. Our results, based on experiments, field data, and models, represent evidence for alternative domains of attraction in ecosystems. An implication of our findings is that nutrient enrichment reduces the resilience of freshwater systems against a shift to floating-plant dominance. On the other hand, our results also suggest that a single drastic harvest of floating plants can induce a permanent shift to an alternative state dominated by rooted, submerged growth forms. PMID:12634429

  4. Prosthetic knee design by simulation

    SciTech Connect

    Hollerbach, K; Hollister, A

    1999-07-30

    Although 150,000 total knee replacement surgeries are performed annually in North America, current designs of knee prostheses have mechanical problems that include a limited range of motion, abnormal gait patterns, patellofemoral joint dysfunction, implant loosening or subsidence, and excessive wear. These problems fall into three categories: failure to reproduce normal joint kinematics, which results in altered limb function; bone-implant interface failure; and material failure. Modern computer technology can be used to design, prototype, and test new total knee implants. The design team uses the full range of CAD-CAM to design and produce implant prototypes for mechanical and clinical testing. Closer approximation of natural knee kinematics and kinetics is essential for improved patient function and diminished implant loads. Current knee replacement designs are based on 19th Century theories that the knee moves about a variable axis of rotation. Recent research has shown, however, that knee motion occurs about two fixed, offset axes of rotation. These aces are not perpendicular to the long axes of the bones or to each other, and the axes do not intersect. Bearing surfaces of mechanisms that move about axes of rotation are surfaces of revolution of those axes which advanced CAD technology can produce. Solids with surfaces of revolution for the two axes of rotation for the knee have been made using an HP9000 workstation and Structural Ideas Master Series CAD software at ArthroMotion. The implant's CAD model should closely replicate movements of the normal knee. The knee model will have a range of flexion-extension (FE) from -5 to 120 degrees. Movements include varus, valgus, internal and external rotation, as well as flexion and extension. The patellofemoral joint is aligned perpendicular to the FE axis and replicates the natural joint more closely than those of existing prostheses. The bearing surfaces will be more congruent than current designs and should

  5. Queen Alexandra's Knee.

    PubMed

    Pinals, Robert S

    2016-06-01

    In 1867, Alexandra, the 22-year-old Princess of Wales, late in her third pregnancy, had sudden onset of a febrile illness. There was a brief period of migratory arthritis, followed by persistent, severe inflammation in 1 knee. A diagnosis of rheumatic fever was made by her physicians, but the course of her illness differed greatly from the expected one. In this report reviewing her disorder, the suggestion is made that she more likely had gonococcal arthritis and that the infection was transmitted to her by her husband, the future King Edward VII, then known as "The Playboy Prince." PMID:27219308

  6. Semi-submersible floating structure

    SciTech Connect

    Finsterwalder, K.

    1981-06-23

    A semi-submersible floating structure includes a horizontal platform with a symmetrical arrangement of buoyant bodies extending vertically downwardly from the platform. The buoyant bodies consist of a tubular column secured by a bending-resistant connection to the platform with a closed container secured to and extending downwardly from the lower end of the tubular column. The horizontal cross-sectional area of the closed container is for most of its vertical height greater than the transverse cross -sectional area of the tubular column. At least the lower portion of the closed container has a curvilinear surface. An annular wall extends around and is spaced radially outwardly from each of the closed containers and the wall, in combination with the enclosed container, forms an annular chamber therebetween open at the bottom and closed at the top. The platform and the buoyant bodies are formed of reinforced concrete or prestressed concrete.

  7. Unicompartmental knee arthroplasty

    PubMed Central

    Murray, D. W.; Liddle, A. D.; Dodd, C. A. F.; Pandit, H.

    2015-01-01

    There is a large amount of evidence available about the relative merits of unicompartmental and total knee arthroplasty (UKA and TKA). Based on the same evidence, different people draw different conclusions and as a result, there is great variability in the usage of UKA. The revision rate of UKA is much higher than TKA and so some surgeons conclude that UKA should not be performed. Other surgeons believe that the main reason for the high revision rate is that UKA is easy to revise and, therefore, the threshold for revision is low. They also believe that UKA has many advantages over TKA such as a faster recovery, lower morbidity and mortality and better function. They therefore conclude that UKA should be undertaken whenever appropriate. The solution to this argument is to minimise the revision rate of UKA, thereby addressing the main disadvantage of UKA. The evidence suggests that this will be achieved if surgeons use UKA for at least 20% of their knee arthroplasties and use implants that are appropriate for these broad indications. Cite this article: Bone Joint J 2015;97-B(10 Suppl A):3–8. PMID:26430080

  8. Osteonecrosis of the knee: review

    PubMed Central

    Karim, Ammar R.; Cherian, Jeffrey J.; Jauregui, Julio J.; Pierce, Todd

    2015-01-01

    Osteonecrosis is a devastating disease that can lead to end-stage arthritis of various joint including the knee. There are three categories of osteonecrosis that affect the knee: spontaneous osteonecrosis of the knee (SONK), secondary, and post-arthroscopic. Regardless of osteonecrosis categories, the treatment of this disease aims to halt further progression or delay the onset of end-stage arthritis of the knee. However, once substantial joint surface collapse has occurred or there are sign of degenerative arthritis, joint arthroplasty is the most appropriate treatment option. Currently, the non-operative treatment options consist of observation, non-steroidal anti-inflammatory drugs (NSAIDs), protected weight bearing, and analgesia as needed. Operative interventions include joint preserving surgery, unilateral knee arthroplasty (UKA), or total knee arthroplasty (TKA) depending on the extent and type of disease. Joint preserving procedures (i.e., arthroscopy, core decompression, osteochondral autograft, and bone grafting) are usually attempted in pre-collapse and some post-collapse lesions, when the articular cartilage is generally intact with only the underlying subchondral bone being affected. Conversely, after severe subchondral collapse has occurred, procedures that attempt to salvage the joint are rarely successful and joint arthroplasty are necessary to relieve pain. The purpose of this article is to highlight the recent evidence concerning the treatment options across the spectrum of management of osteonecrosis of the knee including lesion observation, medications, joint preserving techniques, and total joint arthroplasties. PMID:25705638

  9. New Generation Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A knee brace that uses Space Shuttle propulsion technology has moved a step closer to being available to help knee injury and stroke patients and may possibly benefit patients with birth defects, spinal cord injuries, and post-polio conditions. After years of hard work, inventors at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, have turned over the final design and prototype to industry partners at Horton's Orthotic Lab in Little Rock, Arkansas for further clinical testing. The device, called the Selectively Lockable Knee Brace, may mean faster, less painful rehabilitation for patients by allowing the knee to move when weight is not on the heel. Devices currently on the market lock the knee in a rigid, straight-leg position, or allow continuous free motion. The knee brace is just one example of how space technology is being used to improve the lives of people on Earth. NASA's MSFC inventors Michael Shadoan and Neill Myers are space propulsion engineers who use the same mechanisms and materials to build systems for rockets that they used to design and develop the knee brace.

  10. Myofascial pain in patients waitlisted for total knee arthroplasty

    PubMed Central

    Henry, Richard; Cahill, Catherine M; Wood, Gavin; Hroch, Jennifer; Wilson, Rosemary; Cupido, Tracy; VanDenKerkhof, Elizabeth

    2012-01-01

    BACKGROUND: Knee pain is one of the major sources of pain and disability in developed countries, particularly in aging populations, and is the primary indication for total knee arthroplasty (TKA) in patients with osteoarthritis (OA). OBJECTIVES: To determine the presence of myofascial pain in OA patients waitlisted for TKA and to determine whether their knee pain may be alleviated by trigger point injections. METHODS: Following ethics approval, 25 participants were recruited from the wait list for elective unilateral primary TKA at the study centre. After providing informed consent, all participants were examined for the presence of active trigger points in the muscles surrounding the knee and received trigger point injections of bupivacaine. Assessments and trigger point injections were implemented on the first visit and at subsequent visits on weeks 1, 2, 4 and 8. Outcome measures included the Timed Up and Go test, Brief Pain Inventory, Centre for Epidemiologic Studies Depression Scale, State-Trait Anxiety Inventory and Short-Form McGill Pain Questionnaire. RESULTS: Myofascial trigger points were identified in all participants. Trigger point injections significantly reduced pain intensity and pain interference, and improved mobility. All participants had trigger points identified in medial muscles, most commonly in the head of the gastrocnemius muscle. An acute reduction in pain and improved functionality was observed immediately following intervention, and persisted over the eight-week course of the investigation. CONCLUSION: All patients had trigger points in the vastus and gastrocnemius muscles, and 92% of patients experienced significant pain relief with trigger point injections at the first visit, indicating that a significant proportion of the OA knee pain was myofascial in origin. Further investigation is warranted to determine the prevalence of myofascial pain and whether treatment delays or prevents TKA. PMID:23061082

  11. Floating electron states in covalent semiconductors.

    PubMed

    Matsushita, Yu-ichiro; Furuya, Shinnosuke; Oshiyama, Atsushi

    2012-06-15

    We report first-principles electronic-structure calculations that clarify the floating nature of electron states in covalent semiconductors. It is found that wave functions of several conduction- and valence-band states, including the conduction-band minima, do not distribute near atomic sites, as was taken for granted, but float in interstitial channels in most semiconductors. The directions and shapes of the interstitial channels depend on the crystal symmetry so that mysterious variation of the energy gaps in SiC polymorphs is naturally explained by considering the floating nature. PMID:23004300

  12. Comparison of hip and knee muscle moments in subjects with and without knee pain.

    PubMed

    Manetta, Jennifer; Franz, Laura Hayden; Moon, Chris; Perell, Karen L; Fang, Meika

    2002-12-01

    Elderly subjects with and without knee pain walked at a comfortable pace during gait analysis. Comparison of peak hip and knee internal extensor generalized muscle moments (GMMs) during loading response was made between groups. Walking velocity, peak hip internal extensor GMM, and knee range of motion (ROM) were significantly less for the group with knee pain than for the group without pain. Peak hip internal extensor GMM was strongly correlated with velocity, but peak knee internal extensor GMM was not. Knee ROM limitations may account for the increased peak knee internal extensor GMM in the knee pain group. PMID:12443949

  13. Floating-gated memory based on carbon nanotube field-effect transistors with Si floating dots

    NASA Astrophysics Data System (ADS)

    Seike, Kohei; Fujii, Yusuke; Ohno, Yasuhide; Maehashi, Kenzo; Inoue, Koichi; Matsumoto, Kazuhiko

    2014-01-01

    We have fabricated a carbon nanotube field-effect transistor (CNTFET)-based nonvolatile memory device with Si floating dots. The electrical characteristics of this memory device were compared with those of devices with a HfO2 charge storage layer or Au floating dots. For a sweep width of 6 V, the memory window of the devices with the Si floating dots increased twofold as compared with that of the devices with the HfO2 layer. Moreover, the retention characteristics revealed that, for the device with the Au floating dots, the off-state had almost the same current as the on-state at the 400th s. However, the devices with the Si floating dots had longer-retention characteristics. The results indicate that CNTFET-based devices with Si floating dots are promising candidates for low-power consumption nonvolatile memory devices.

  14. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  15. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  16. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  17. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  18. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  19. 14 CFR 23.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float design. 23.753 Section 23.753... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Floats and Hulls § 23.753 Main float design. Each seaplane main float must meet the requirements of § 23.521....

  20. 14 CFR 27.751 - Main float buoyancy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float buoyancy. 27.751 Section 27.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.751 Main float buoyancy. (a) For main floats, the...

  1. 14 CFR 29.751 - Main float buoyancy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.751 Main float buoyancy. (a) For main floats,...

  2. 14 CFR 25.751 - Main float buoyancy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float buoyancy. 25.751 Section 25.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Floats and Hulls § 25.751 Main float buoyancy. Each main float must have— (a)...

  3. Program Converts VAX Floating-Point Data To UNIX

    NASA Technical Reports Server (NTRS)

    Alves, Marcos; Chapman, Bruce; Chu, Eugene

    1996-01-01

    VAX Floating Point to Host Floating Point Conversion (VAXFC) software converts non-ASCII files to unformatted floating-point representation of UNIX machine. This is done by reading bytes bit by bit, converting them to floating-point numbers, then writing results to another file. Useful when data files created by VAX computer must be used on other machines. Written in C language.

  4. 14 CFR 23.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 23.753 Section 23.753... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Floats and Hulls § 23.753 Main float design. Each seaplane main float must meet the requirements of § 23.521....

  5. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  6. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  7. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  8. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  9. Cosmetic effect of knee joint in a knee disarticulation prosthesis.

    PubMed

    de Laat, Fred A; van der Pluijm, Mark J; van Kuijk, Annette A; Geertzen, Jan H; Roorda, Leo D

    2014-01-01

    Despite numerous advantages, knee disarticulations (KDs) are rarely performed because of the anticipated KD prosthesis fitting problems that include the positioning of the knee joint distally from the KD socket. This results in lengthening of the thigh and subsequent shortening of the shank. The objective of this study was to assess the cosmetic effect of the knee joint in a KD prosthesis by determining the extent of the lengthening of the thigh and the shortening of the shank. This lengthening and shortening were measured through an experimental setup using laser techniques. These measurements were made of 18 knee joints used in KD prostheses. Lengthening of the thigh varied between 23 and 92 mm, and shortening of the shank varied between 3 and 50 mm. The polycentric knees Medi KH6 and Medi KHF1 showed the least lengthening of the thigh, and the polycentric knees Teh Lin Prosthetic & Orthotic Co. Ltd Graph-Lite and Medi KP5 showed the least shortening of the shank. PMID:25856500

  10. Surface tension supported floating of heavy objects: Why elongated bodies float better?

    PubMed

    Bormashenko, Edward

    2016-02-01

    Floating of bodies heavier than the supporting liquid is discussed. Floating of cylindrical, ellipsoidal bodies and rectangular plates possessing lateral dimensions smaller than the capillary length is treated. It is demonstrated that more elongated bodies of a fixed volume are better supported by capillary forces, due to the increase in the perimeter of the triple line. Thus, floating of metallic needles obtains reasonable explanation. PMID:26513731

  11. Intraarticular osteochondroma of the knee

    PubMed Central

    Morey, Vivek Morey; Jalan, Divesh; Mittal, Ravi; Gamangatti, Shivanand

    2014-01-01

    Osteochondromas are usually extra articular and grow away from the joint towards the diaphysis. Intraarticular osteochondromas are very rare and often misdiagnosed. We report a case of 16-year-old boy who presented with pain and clicking sound in the right knee for last 6 months. On examination, click was felt at the terminal flexion of the knee. The lateral radiograph of the right knee showed a radio opaque shadow at the posterior aspect of the distal end of femur, which was further evaluated with an MRI. Arthroscopy showed a hard lesion arising from the roof of the intercondylar notch of femur. It was excised arthroscopically. Histopathology revealed it to be an osteochondroma. Thus, intraarticular osteochondroma of the knee can be considered as a rare cause of pain in young patients. PMID:24932044

  12. Anterior Knee Pain (Chondromalacia Patellae).

    ERIC Educational Resources Information Center

    Garrick, James G.

    1989-01-01

    This article presents a pragmatic approach to the definition, diagnosis, and management of anterior knee pain. Symptoms and treatment are described. Emphasis is on active involvement of the patient in the rehabilitation exercise program. (IAH)

  13. Minimally Invasive Total Knee Arthroplasty

    MedlinePlus

    ... and drill her. And how much are you rotating there? This rotates 3 degrees externally with respect ... femoral components that can be used. With the rotating knee system, a class III device at this ...

  14. Knee Brace Would Lock And Unlock Automatically

    NASA Technical Reports Server (NTRS)

    Myers, Neill; Forbes, John; Shadoan, Mike; Baker, Kevin

    1995-01-01

    Proposed knee brace designed to aid rehabilitation of person who suffered some muscle damage in leg. Not limited to locking in straight-leg position and, instead, locks at any bend angle. Does not prevent knee from bearing weight. Instead, knee brace allows knee to bear weight and locks only when foot and lower leg bear weight. Thus, brace prevents flexion that wearer desired to prevent but could not prevent because of weakened muscles. Knee bends freely to exercise knee-related muscles. Knee brace strapped at upper end to leg above knee, and anchored at lower end by stirrup under foot. Joint mechanism (identical mechanisms used in left and right assemblies) allows knee joint to flex freely except when weight applied to heel.

  15. Analysis of Joint Sounds in the Diagnosis of Knee Disorders

    ClinicalTrials.gov

    2015-07-22

    Healthy Patients; No Knee Complaints; No Knee Injuries; No Knee Surgeries; No Neurological Problems; Patients Undergoing Knee Arthroscopy, Who Has a Pre-op MRI; Age Groups of 20,40 and 60 Years of Age.

  16. Exploring Floating Concrete and Beam Design.

    ERIC Educational Resources Information Center

    Snell, Billie G.; Snell, Luke M.

    2002-01-01

    Presents two construction activities that address both state and federal science standards and encourage students to consider career options in mathematics and science. Includes floating concrete and paper bridge activities. (YDS)

  17. Lagrangian floats as sea floor imaging platforms

    NASA Astrophysics Data System (ADS)

    Roman, Chris; Inglis, Gabrielle; McGilvray, Bryan

    2011-10-01

    There is a persistent need for high resolution photographic images of the sea floor and associated biota for marine habitat classification and fisheries stock assessment. This paper presents a novel low cost Lagrangian imaging platform that offers high quality images with reduced operational demands in comparison to existing methodologies such as diver surveys, drop cameras, ship towed systems and dedicated remote or autonomous underwater vehicles. The platform consists of a recently developed bottom following Lagrangian float fit with down looking stereo cameras and strobe lighting. The float can use active ballasting to perform constant altitude photographic drift surveys in coastal waters over varying bathymetry. Images from the float can be used to create large photomosaics, stereographic bathymetry estimates and image-derived current measurements. Test data are presented to demonstrate the operation of the Lagrangian float and summarize the data products.

  18. Archimedes' floating bodies on a spherical Earth

    NASA Astrophysics Data System (ADS)

    Rorres, Chris

    2016-01-01

    Archimedes was the first to systematically find the centers of gravity of various solid bodies and to apply this concept in determining stable configurations of floating bodies. In this paper, we discuss an error in a proof developed by Archimedes that involves determining whether a uniform, spherical cap will float stably with its base horizontal in a liquid on a spherical Earth. We present a simpler, corrected proof and discuss aspects of his proof regarding a spherical cap that is not uniform.

  19. Floating phenomenon and mode of color appearance

    NASA Astrophysics Data System (ADS)

    Aoki, Hironobu; Shinoda, Hiroyuki; Ikeda, Mitsuo

    2002-06-01

    We found an interesting phenomenon concerning the motion perception and the mode of color appearance. We suppose you are holding a stiff sheet of picture and move it laterally to and fro in front of the eye. Though the picture and all items in it move physically altogether with your hand, your perception is not always so. But when the picture that is a figure appears light-source color mode and a background of object color, a figure appears to slip on a background. We call this a 'floating phenomenon.' We predicted the occurrence of floating phenomenon depends on whether the color is perceived to belong to an object or not. To examine the relation between the floating phenomenon and the mode of color appearance, we measured the luminance threshold of floating phenomenon and the transition luminance between two color modes by constant stimulus method to use a mondrian. Our results show the floating never occurred when the target appeared as object color mode. The floating phenomenon may be caused by the separation of the light-source color from an object or week-belonging.

  20. [Eco-epidemiology: towards epidemiology of complexity].

    PubMed

    Bizouarn, Philippe

    2016-05-01

    In order to solve public health problems posed by the epidemiology of risk factors centered on the individual and neglecting the causal processes linking the risk factors with the health outcomes, Mervyn Susser proposed a multilevel epidemiology called eco-epidemiology, addressing the interdependence of individuals and their connection with molecular, individual, societal, environmental levels of organization participating in the causal disease processes. The aim of this epidemiology is to integrate more than a level of organization in design, analysis and interpretation of health problems. After presenting the main criticisms of risk-factor epidemiology focused on the individual, we will try to show how eco-epidemiology and its development could help to understand the need for a broader and integrative epidemiology, in which studies designed to identify risk factors would be balanced by studies designed to answer other questions equally vital to public health. PMID:27225924

  1. Floating intake reduces pump damage

    SciTech Connect

    Kronig, A.

    1993-12-31

    The solution to a costly sand erosion problem at the Grande Dixence hydroelectric project in Switzerland turned out to be as simple as a floating pump. The 726-MW Grande Dixence project drains a 350-square-kilometer reach of the Zermatt and Herens valleys in the southwestern Swiss Alps. About half of the drainage area is covered by active glaciers. Because the glaciers in Zermatt Valley are so low in altitude, their water is collected in Z`mutt Reservoir at the base of the Matterhorn, then pumped up 500 meters for transport to the main Grande Disence Reservoir near Sion. The glacier water is heavily laden with sand. In spite of a gravel pass and a desilter, the 700,000-acubic-meter Z`mutt Reservoir receives large quantities of sand. The sand tends to remain in solution because of the low water temperatures (1 to 2 degrees Centigrade). In the original intake system, the sand would be sucked into the pump intakes, causing extensive erosion to the pump wheels and an expensive yearly program of repair. (Pump damage averaged 200,000 Swiss Francs ($284,000 U.S.) per year between 1980 and 1985.)

  2. Cadmium uptake by floating macrophytes.

    PubMed

    Maine, M A; Duarte, M V; Suñé, N L

    2001-08-01

    Cd uptake capacity of a group of floating macrophytes (Salvinia herzogii, Pistia stratiotes, Hydromistia stolonifera and Eichhornia crassipes) was determined in outdoors experiments during the lowest temperature period of the year. Although all studied species were highly efficient in the Cd uptake, Pistia stratiotes was selected for further research because of its superior performance and its higher average relative growth rate. Cadmium% removal by Pistia stratiotes was greater in the first 24 h of the experiments (63, 65, 72 and 74% of the added Cd for 1, 2, 4 and 6 mg Cd 1(-1), respectively). After 31 days of growth, Pistia statiotes efficiently removed Cd at the studied concentrations. The macrophyte was able to keep its capacity for Cd removal even though some toxicity symptoms appeared at 4 and 6 mg Cd 1(-1). The greater the initial concentration, the greater Cd bioaccumulation rates. The increase of Cd concentration in plant tissues occurred especially in roots and was linearly related to the quantity of Cd added. Cd sorption by roots is faster than translocation to the plant aerial part and it occurs mainly during the first 24h. PMID:11456161

  3. Changes in knee kinematics following total knee arthroplasty.

    PubMed

    Akbari Shandiz, Mohsen; Boulos, Paul; Saevarsson, Stefan Karl; Yoo, Sam; Miller, Stephen; Anglin, Carolyn

    2016-04-01

    Total knee arthroplasty (TKA) changes the knee joint in both intentional and unintentional, known and unknown, ways. Patellofemoral and tibiofemoral kinematics play an important role in postoperative pain, function, satisfaction and revision, yet are largely unknown. Preoperative kinematics, postoperative kinematics or changes in kinematics may help identify causes of poor clinical outcome. Patellofemoral kinematics are challenging to record since the patella is obscured by the metal femoral component in X-ray and moves under the skin. The purpose of this study was to determine the kinematic degrees of freedom having significant changes and to evaluate the variability in individual changes to allow future study of patients with poor clinical outcomes. We prospectively studied the 6 degrees of freedom patellofemoral and tibiofemoral weightbearing kinematics, tibiofemoral contact points and helical axes of rotation of nine subjects before and at least 1 year after total knee arthroplasty using clinically available computed tomography and radiographic imaging systems. Normal kinematics for healthy individuals were identified from the literature. Significant differences existed between pre-TKA and post-TKA kinematics, with the post-TKA kinematics being closer to normal. While on average the pre-total knee arthroplasty knees in this group displayed no pivoting (only translation), individually only five knees displayed this behaviour (of these, two showed lateral pivoting, one showed medial pivoting and one showed central pivoting). There was considerable variability postoperatively as well (five central, two lateral and two medial pivoting). Both preop and postop, flexion behaviour was more hinge-like medially and more rolling laterally. Helical axes were more consistent postop for this group. An inclusive understanding of the pre-TKA and post-TKA kinematics and changes in kinematics due to total knee arthroplasty could improve implant design, patient diagnosis and

  4. Will 'Unloading' Shoes Help Your Arthritic Knees?

    MedlinePlus

    ... 160406.html Will 'Unloading' Shoes Help Your Arthritic Knees? Study puts specially designed footwear to the test ... 2016 (HealthDay News) -- For reducing pain from arthritic knees, "unloading" shoes don't offer a leg up ...

  5. Knee joint forces: prediction, measurement, and significance

    PubMed Central

    D’Lima, Darryl D.; Fregly, Benjamin J.; Patil, Shantanu; Steklov, Nikolai; Colwell, Clifford W.

    2011-01-01

    Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined. PMID:22468461

  6. Deciding to have knee or hip replacement

    MedlinePlus

    ... patientinstructions/000368.htm Deciding to have knee or hip replacement To use the sharing features on this page, ... make a decision. Who Benefits From Knee or hip Replacement Surgery? The most common reason to have a ...

  7. Risks of hip and knee replacement

    MedlinePlus

    ... is normal to lose blood during and after hip or knee replacement surgery. Some people need a blood transfusion during ... clot form are higher during and soon after hip or knee replacement surgery. Sitting or lying down for long periods ...

  8. Knee joint forces: prediction, measurement, and significance.

    PubMed

    D'Lima, Darryl D; Fregly, Benjamin J; Patil, Shantanu; Steklov, Nikolai; Colwell, Clifford W

    2012-02-01

    Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined. PMID:22468461

  9. Early knee osteoarthritis

    PubMed Central

    Favero, Marta; Ramonda, Roberta; Goldring, Mary B; Goldring, Steven R; Punzi, Leonardo

    2015-01-01

    Concepts regarding osteoarthritis, the most common joint disease, have dramatically changed in the past decade thanks to the development of new imaging techniques and the widespread use of arthroscopy that permits direct visualisation of intra-articular tissues and structure. MRI and ultrasound allow the early detection of pre-radiographic structural changes not only in the peri-articular bone but also in the cartilage, menisci, synovial membrane, ligaments and fat pad. The significance of MRI findings such as cartilage defects, bone marrow lesions, synovial inflammation/effusions and meniscal tears in patients without radiographic signs of osteoarthritis is not fully understood. Nevertheless, early joint tissue changes are associated with symptoms and, in some cases, with progression of disease. In this short review, we discuss the emerging concept of early osteoarthritis localised to the knee based on recently updated knowledge. We highlight the need for a new definition of early osteoarthritis that will permit the identification of patients at high risk of osteoarthritis progression and to initiate early treatment interventions. PMID:26557380

  10. TOTAL KNEE REPLACEMENT IN PATIENTS WITH BELOW-KNEE AMPUTATION

    PubMed Central

    Karam, Matthew D; Willey, Michael; Shurr, Donald G

    2010-01-01

    Total knee replacement (TKR) is reserved for patients with severe and disabling arthritis that is non-responsive to conservative measures. Based on existing data, total knee replacement is a safe and cost-effective treatment for alleviating pain and improving physical function in patients who do not respond to conservative therapy. Despite the large variation in health status of patients and types of prosthesis implanted, total knee replacement has proven to be a relatively low risk and successful operation. Each year in the United States surgeons perform approximately 300,000 TKR.1 Likewise, lower extremity amputation is commonly performed in the United States with an annual incidence of 110,000 per year.2 Nearly 70% of all lower extremity amputations are performed as the result of chronic vascular disease, followed by trauma (22%), congenital etiology and tumor (4% each).3 Approximately 50% of all lower extremity amputations are performed secondary to complications from Diabetes Mellitus. Norvell et al. demonstrated that patients who have previously undergone transtibial amputation and ambulate with a prosthesis are more likely to develop degenerative joint disease in the con-tralateral extremity than the ipsilateral extremity.4 Further, radiographic changes consistent with osteoporosis have been demonstrated in up to 88% of limbs that have undergone transtibial amputation.8 To our knowledge, there have been only three reported cases of total knee replacement in patients with ipsilateral transtibial amputation.5,7 The purpose of the present study is to review the existing data on total knee replacement in patients who have undergone transtibial amputation. Further we present a patient with a transtibial amputation who underwent contralateral total knee replacement. PMID:21045987

  11. Battery charging in float vs. cycling environments

    SciTech Connect

    COREY,GARTH P.

    2000-04-20

    In lead-acid battery systems, cycling systems are often managed using float management strategies. There are many differences in battery management strategies for a float environment and battery management strategies for a cycling environment. To complicate matters further, in many cycling environments, such as off-grid domestic power systems, there is usually not an available charging source capable of efficiently equalizing a lead-acid battery let alone bring it to a full state of charge. Typically, rules for battery management which have worked quite well in a floating environment have been routinely applied to cycling batteries without full appreciation of what the cycling battery really needs to reach a full state of charge and to maintain a high state of health. For example, charge target voltages for batteries that are regularly deep cycled in off-grid power sources are the same as voltages applied to stand-by systems following a discharge event. In other charging operations equalization charge requirements are frequently ignored or incorrectly applied in cycled systems which frequently leads to premature capacity loss. The cause of this serious problem: the application of float battery management strategies to cycling battery systems. This paper describes the outcomes to be expected when managing cycling batteries with float strategies and discusses the techniques and benefits for the use of cycling battery management strategies.

  12. Floating seal system for rotary devices

    DOEpatents

    Banasiuk, H.A.

    1983-08-23

    This invention relates to a floating seal system for rotary devices to reduce gas leakage around the rotary device in a duct and across the face of the rotary device to an adjacent duct. The peripheral seal bodies are made of resilient material having a generally U-shaped cross section wherein one of the legs is secured to a support member and the other of the legs forms a contacting seal against the rotary device. The legs of the peripheral seal form an extended angle of intersection of about 10[degree] to about 30[degree] in the unloaded condition to provide even sealing forces around the periphery of the rotary device. The peripheral seal extends around the periphery of the support member except where intersected by radial seals which reduce gas leakage across the face of the rotary device and between adjacent duct portions. The radial seal assembly is fabricated from channel bars, the smaller channel bar being secured to the divider of the support member and a larger inverted rigid floating channel bar having its legs freely movable over the legs of the smaller channel bar forming therewith a tubular channel. A resilient flexible tube is positioned within the tubular channel for substantially its full length to reduce gas leakage across the tubular channel. A spacer extends beyond the face of the floating channel near each end of the floating channel a distance to provide desired clearance between the floating channel and the face of the rotary device. 5 figs.

  13. Floating seal system for rotary devices

    DOEpatents

    Banasiuk, Hubert A.

    1983-01-01

    This invention relates to a floating seal system for rotary devices to reduce gas leakage around the rotary device in a duct and across the face of the rotary device to an adjacent duct. The peripheral seal bodies are made of resilient material having a generally U-shaped cross section wherein one of the legs is secured to a support member and the other of the legs forms a contacting seal against the rotary device. The legs of the peripheral seal form an extended angle of intersection of about 10.degree. to about 30.degree. in the unloaded condition to provide even sealing forces around the periphery of the rotary device. The peripheral seal extends around the periphery of the support member except where intersected by radial seals which reduce gas leakage across the face of the rotary device and between adjacent duct portions. The radial seal assembly is fabricated from channel bars, the smaller channel bar being secured to the divider of the support member and a larger inverted rigid floating channel bar having its legs freely movable over the legs of the smaller channel bar forming therewith a tubular channel. A resilient flexible tube is positioned within the tubular channel for substantially its full length to reduce gas leakage across the tubular channel. A spacer extends beyond the face of the floating channel near each end of the floating channel a distance to provide desired clearance between the floating channel and the face of the rotary device.

  14. Self-reported previous knee injury and low knee function increase knee injury risk in adolescent female football.

    PubMed

    Clausen, M B; Tang, L; Zebis, M K; Krustrup, P; Hölmich, P; Wedderkopp, N; Andersen, L L; Christensen, K B; Møller, M; Thorborg, K

    2016-08-01

    Knee injuries are common in adolescent female football. Self-reported previous knee injury and low Knee injury and Osteoarthritis Outcome Score (KOOS) are proposed to predict future knee injuries, but evidence regarding this in adolescent female football is scarce. The aim of this study was to investigate self-reported previous knee injury and low KOOS subscale score as risk factors for future knee injuries in adolescent female football. A sample of 326 adolescent female football players, aged 15-18, without knee injury at baseline, were included. Data on self-reported previous knee injury and KOOS questionnaires were collected at baseline. Time-loss knee injuries and football exposures were reported weekly by answers to standardized text-message questions, followed by injury telephone interviews. A priori, self-reported previous knee injury and low KOOS subscale scores (< 80 points) were chosen as independent variables in the risk factor analyses. The study showed that self-reported previous knee injury significantly increased the risk of time-loss knee injury [relative risk (RR): 3.65, 95% confidence (CI) 1.73-7.68; P < 0.001]. Risk of time-loss knee injury was also significantly increased in players with low KOOS subscale scores (< 80 points) in Activities of Daily Living (RR: 5.0), Sport/Recreational (RR: 2.2) and Quality of Life (RR: 3.0) (P < 0.05). In conclusion, self-reported previous knee injury and low scores in three KOOS subscales significantly increase the risk of future time-loss knee injury in adolescent female football. PMID:26179111

  15. Snapping knee caused by symptomatic fabella in a native knee.

    PubMed

    Hire, Justin M; Oliver, David L; Hubbard, Ryan C; Fontaine, Michelle L; Bojescul, John A

    2014-08-01

    We report a case of a 31-year-old man with a 5-year history of snapping knee syndrome secondary to a single, large symptomatic fabella of the knee. On physical examination, the patient was able to reproduce an audible and palpable snapping with active range of motion. His condition was refractory to physical therapy. He had undergone a prior iliotibial band release at an outside facility. After excision of the fabella, measuring 15 × 8 × 9 mm, the patient's snapping and pain with activity were resolved. PMID:25136872

  16. Automatically Locking/Unlocking Orthotic Knee Joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1994-01-01

    Proposed orthotic knee joint locks and unlocks automatically, at any position within range of bend angles, without manual intervention by wearer. Includes tang and clevis, locks whenever wearer transfers weight to knee and unlocks when weight removed. Locking occurs at any angle between 45 degrees knee bend and full extension.

  17. Knee Replacement - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Knee Replacement (Arabic) العربية Bilingual PDF Health Information Translations Bosnian (Bosanski) Total Knee Replacement Potpuna zamjena koljena - Bosanski (Bosnian) Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) Total Knee Replacement 全膝关节置换 - 简体中文 ( ...

  18. [Imaging strategies for knee injuries].

    PubMed

    Hegenscheid, K; Puls, R; Rosenberg, C

    2012-11-01

    Injuries of the knees are common. The Ottawa knee rule provides decisional support to determine whether radiographs are indicated or not. With the use of ultrasound it is possible to detect defects of the extensor ligaments and the anterior cruciate ligament. Furthermore, it is possible to detect indirect signs of an intra-articular fracture, e.g. lipohemarthrosis. In complex fractures, e.g. tibial plateau fractures, further diagnostic procedures with multislice computed tomography (CT) are needed for accurate classification and preoperative planning. Multislice CT with CT angiography enables three-dimensional reconstruction of the knee and non-invasive vascular imaging for detection of vascular injury. Magnetic resonance imaging (MRI) is the gold standard for detection of occult fractures and injuries of the ligaments and menisci. Higher field strengths can be used to improve the diagnostics of cartilage lesions. Virtual MR arthrography is superior to conventional MRI for detection of cartilage lesions especially after meniscus surgery. PMID:23154845

  19. Robotic-assisted knee arthroplasty.

    PubMed

    Banerjee, Samik; Cherian, Jeffrey J; Elmallah, Randa K; Jauregui, Julio J; Pierce, Todd P; Mont, Michael A

    2015-01-01

    Robotics in total knee arthroplasty (TKA) has undergone vast improvements. Although some of the systems have fallen out of favor due to safety concerns, there has been recent increased interest for semi-active haptic robotic systems that provide intraoperative tactile feedback to the surgeon. The potential advantages include improvements in radiographic outcomes, reducing the incidence of mechanical axis malalignment of the lower extremity and better tissue balance. Proponents of robotic technology believe that these improvements may lead to superior functional outcomes and implant survivorship. We aim to discuss robotic technology development, outcomes of unicompartmental and total knee arthroplasty and the future outlook. Short-term follow-up studies on robotic-assisted knee arthroplasty suggest that, although some alignment objectives may have been achieved, more studies regarding functional outcomes are needed. Furthermore, studies evaluating the projected cost-benefit analyses of this new technology are needed before widespread adoption. Nevertheless, the short-term results warrant further evaluation. PMID:26365088

  20. Early osteoarthritis of the knee.

    PubMed

    Madry, Henning; Kon, Elizaveta; Condello, Vincenzo; Peretti, Giuseppe M; Steinwachs, Matthias; Seil, Romain; Berruto, Massimo; Engebretsen, Lars; Filardo, Giuseppe; Angele, Peter

    2016-06-01

    There is an increasing awareness on the importance in identifying early phases of the degenerative processes in knee osteoarthritis (OA), the crucial period of the disease when there might still be the possibility to initiate treatments preventing its progression. Early OA may show a diffuse and ill-defined involvement, but also originate in the cartilage surrounding a focal lesion, thus necessitating a separate assessment of these two entities. Early OA can be considered to include a maximal involvement of 50 % of the cartilage thickness based on the macroscopic ICRS classification, reflecting an OARSI grade 4. The purpose of this paper was to provide an updated review of the current status of the diagnosis and definition of early knee OA, including the clinical, radiographical, histological, MRI, and arthroscopic definitions and biomarkers. Based on current evidence, practical classification criteria are presented. As new insights and technologies become available, they will further evolve to better define and treat early knee OA. PMID:27000393

  1. Floating zone melting of cadmium telluride

    NASA Technical Reports Server (NTRS)

    Chang, Wen-Ming; Regel, L. L.; Wilcox, W. R.

    1992-01-01

    To produce superior crystals of cadmium telluride, floating zone melting in space has been proposed. Techniques required for floating zone melting of cadmium telluride are being developed. We have successfully float-zoned cadmium telluride on earth using square rods. A resistance heater was constructed for forming the molten zone. Evaporation of the molten zone was controlled by adding excess cadmium to the growth ampoule combined with heating of the entire ampoule. An effective method to hold the feed rod was developed. Slow rotation of the growth ampoule was proven experimentally to be necessary to achieve a complete symmetric molten zone. Most of the resultant cylindrical rods were single crystals with twins. Still needed is a suitable automatic method to control the zone length. We tried a fiber optical technique to control the zone length, but experiments showed that application of this technique to automate zone length control is unlikely to be successful.

  2. Floating mechanism of a small liquid marble

    NASA Astrophysics Data System (ADS)

    Ooi, Chin Hong; Plackowski, Chris; Nguyen, Anh V.; Vadivelu, Raja K.; John, James A. St.; Dao, Dzung Viet; Nguyen, Nam-Trung

    2016-02-01

    Flotation of small solid objects and liquid droplets on water is critical to natural and industrial activities. This paper reports the floating mechanism of liquid marbles, or liquid droplets coated with hydrophobic microparticles. We used X-ray computed tomography (XCT) to acquire cross-sectional images of the floating liquid marble and interface between the different phases. We then analysed the shape of the liquid marble and the angles at the three-phase contact line (TPCL). We found that the small floating liquid marbles follow the mechanism governing the flotation of solid objects in terms of surface tension forces. However, the contact angles formed and deformation of the liquid marble resemble that of a sessile liquid droplet on a thin, elastic solid. For small liquid marbles, the contact angle varies with volume due to the deformability of the interface.

  3. Vibration characteristics of floating slab track

    NASA Astrophysics Data System (ADS)

    Kuo, Chen-Ming; Huang, Cheng-Hao; Chen, Yi-Yi

    2008-11-01

    Coupled equilibrium equations of suspended wheels and floating slab track system were solved with the fourth-order Runge-Kutta method to obtain the deflections, vibration velocities, and wheel-rail contact forces. The program was validated through several aspects. Cases with various vehicle speed, slab mass, and stiffness of slab bearing were analyzed to reveal the effects of slab bearing on track responses. The correlation between wheel-rail resonance and train speed was also discussed. It was found that rail deflections increase significantly as train speed increases. Although large slab mass may lower tuning frequency, it could also result in higher wheel-rail contact force and rail deflections. The floating slab track is effective in isolating loading above 10 Hz, which might present in some railway sections with irregularities. Adopting floating slab track for vibration control for environment along the railway may cause concerns about ride quality and track damages.

  4. Floating mechanism of a small liquid marble

    PubMed Central

    Ooi, Chin Hong; Plackowski, Chris; Nguyen, Anh V.; Vadivelu, Raja K.; John, James A. St.; Dao, Dzung Viet; Nguyen, Nam-Trung

    2016-01-01

    Flotation of small solid objects and liquid droplets on water is critical to natural and industrial activities. This paper reports the floating mechanism of liquid marbles, or liquid droplets coated with hydrophobic microparticles. We used X-ray computed tomography (XCT) to acquire cross-sectional images of the floating liquid marble and interface between the different phases. We then analysed the shape of the liquid marble and the angles at the three-phase contact line (TPCL). We found that the small floating liquid marbles follow the mechanism governing the flotation of solid objects in terms of surface tension forces. However, the contact angles formed and deformation of the liquid marble resemble that of a sessile liquid droplet on a thin, elastic solid. For small liquid marbles, the contact angle varies with volume due to the deformability of the interface. PMID:26902930

  5. Floating mechanism of a small liquid marble.

    PubMed

    Ooi, Chin Hong; Plackowski, Chris; Nguyen, Anh V; Vadivelu, Raja K; John, James A St; Dao, Dzung Viet; Nguyen, Nam-Trung

    2016-01-01

    Flotation of small solid objects and liquid droplets on water is critical to natural and industrial activities. This paper reports the floating mechanism of liquid marbles, or liquid droplets coated with hydrophobic microparticles. We used X-ray computed tomography (XCT) to acquire cross-sectional images of the floating liquid marble and interface between the different phases. We then analysed the shape of the liquid marble and the angles at the three-phase contact line (TPCL). We found that the small floating liquid marbles follow the mechanism governing the flotation of solid objects in terms of surface tension forces. However, the contact angles formed and deformation of the liquid marble resemble that of a sessile liquid droplet on a thin, elastic solid. For small liquid marbles, the contact angle varies with volume due to the deformability of the interface. PMID:26902930

  6. Arthroscopic surgery of the knee.

    PubMed Central

    Dandy, D J; O'Carroll, P F

    1982-01-01

    In the first 1000 arthroscopic operations performed by one surgeon 136 patients had two or more procedures, making a total of 1168 during the 1000 operations. The indications for operation were internal mechanical derangements in 565 patients, anterior knee pain in 246, disorders of the synovium in 77, ligament injuries in 63, and degenerative joint disease in 49. Complications included fracture of instruments in the knee in five patients, haemarthrosis in 10, deep vein thrombosis in three, and synovial fistula in one. In no patient was the wound infected. A total of 26 different operations was performed. PMID:6812832

  7. [Revision after unicompartmental knee arthroplasty].

    PubMed

    Mohr, G; Martin, J; Clarius, M

    2014-10-01

    Unicompartmental arthroplasty is an efficient and approved treatment option of unicompartmental arthritis of the knee, being performed with increasing frequency worldwide. Compared to total knee replacement, there are several advantages such as faster recovery, lower blood loss, better functional outcome and lower infection rates. However, higher revision rates are a frequent argument against the use of unicompartmental arthroplasty. The following article gives an overview of failure mechanisms and strategies for revision arthroplasty. This article is based on a selective literature review including PubMed and relevant print media. Our own clinical experience is considered as well. PMID:25209015

  8. International Lymphoma Epidemiology Consortium

    Cancer.gov

    The InterLymph Consortium, or formally the International Consortium of Investigators Working on Non-Hodgkin's Lymphoma Epidemiologic Studies, is an open scientific forum for epidemiologic research in non-Hodgkin's lymphoma.

  9. Improvements in floating point addition/subtraction operations

    DOEpatents

    Farmwald, P.M.

    1984-02-24

    Apparatus is described for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  10. Trabecular bone strength at the knee.

    PubMed

    Hvid, I

    1988-02-01

    The axial strength of trabecular bone at the knee is critical for the maintenance of support and fixation of the prosthetic components after total surface knee arthroplasty. The resistance of trabecular bone to penetration was measured posteriorly, centrally, and anteriorly in each of the tibial and femoral condyles in 150 consecutive total knee arthroplasties. Forty-seven rheumatoid knees and 88 osteoarthritic knees were evaluated. The correlation of bone strength with selected clinical parameters was found to be too poor to predict bone strength. Tibial bone strength was lower in rheumatoid than in osteoarthritic knees. Steroid medication did not influence tibial bone strength in rheumatoid arthritis. The distribution of bone strength between the medial and lateral condyles was closely dependent on knee alignment, with high medial strength in varus knees. At the unloaded condyle, strength was reduced relative to the findings for normally aligned knees. At the tibia, strength decreased with depth from the resection surface, while at the femur the converse was true. Tibial bone strength, both condylar and overall average, was lower than values reported in studies of normal cadaver knees. Evaluation of the absolute bone strength at the tibial condyles suggested that the values too low to meet load-bearing requirements after well-aligned knee replacement were infrequent. PMID:3276421

  11. Deprivation and outcome of total knee replacement.

    PubMed

    Murray, James R D; Birdsall, Paul D; Sher, J Lester; Deehan, David J

    2006-03-01

    Deprivation correlates with poor health and psychosocial variables can affect the symptoms of knee arthritis. Our aim was to determine the effect of deprivation on the level of knee function and health-related quality of life at the time of arthroplasty and 12 months after total knee replacement. From our database of over 2500 knee replacements, we analysed both clinical and quality of life outcome measures. We analysed the relationship between deprivation (by Townsend score), knee function (Knee Society Score) and health-related quality of life (Nottingham Health Profile) before total knee replacement (TKR) and at 12 months post-operation. There was no significant correlation between Townsend score, Knee Society Score and Nottingham Health Profile preoperatively or at 12 months after knee replacement, thus showing that there was no association between deprivation and the severity of knee arthritis at the time of joint replacement nor was there a relationship between deprivation and the short-term outcome from total knee replacement. PMID:16469499

  12. Biomechanics of knee joint — A review

    NASA Astrophysics Data System (ADS)

    Madeti, Bhaskar Kumar; Chalamalasetti, Srinivasa Rao; Bolla Pragada, S. K. Sundara siva rao

    2015-06-01

    The present paper is to know how the work is carried out in the field of biomechanics of knee. Various model formulations are discussed and further classified into mathematical model, two-dimensional model and three-dimensional model. Knee geometry is a crucial part of human body movement, in which how various views of knee is shown in different planes and how the forces act on tibia and femur are studied. It leads to know the forces acting on the knee joint. Experimental studies of knee geometry and forces acting on knee shown by various researchers have been discussed, and comparisons of results are made. In addition, static and dynamic analysis of knee has been also discussed respectively to some extent.

  13. Open Knee: Open Source Modeling and Simulation in Knee Biomechanics.

    PubMed

    Erdemir, Ahmet

    2016-02-01

    Virtual representations of the knee joint can provide clinicians, scientists, and engineers the tools to explore mechanical functions of the knee and its tissue structures in health and disease. Modeling and simulation approaches such as finite element analysis also provide the possibility to understand the influence of surgical procedures and implants on joint stresses and tissue deformations. A large number of knee joint models are described in the biomechanics literature. However, freely accessible, customizable, and easy-to-use models are scarce. Availability of such models can accelerate clinical translation of simulations, where labor-intensive reproduction of model development steps can be avoided. Interested parties can immediately utilize readily available models for scientific discovery and clinical care. Motivated by this gap, this study aims to describe an open source and freely available finite element representation of the tibiofemoral joint, namely Open Knee, which includes the detailed anatomical representation of the joint's major tissue structures and their nonlinear mechanical properties and interactions. Three use cases illustrate customization potential of the model, its predictive capacity, and its scientific and clinical utility: prediction of joint movements during passive flexion, examining the role of meniscectomy on contact mechanics and joint movements, and understanding anterior cruciate ligament mechanics. A summary of scientific and clinically directed studies conducted by other investigators are also provided. The utilization of this open source model by groups other than its developers emphasizes the premise of model sharing as an accelerator of simulation-based medicine. Finally, the imminent need to develop next-generation knee models is noted. These are anticipated to incorporate individualized anatomy and tissue properties supported by specimen-specific joint mechanics data for evaluation, all acquired in vitro from varying age

  14. Cancer Epidemiology Matters Blog

    Cancer.gov

    The Cancer Epidemiology Matters blog helps foster a dialogue between the National Cancer Institute's (NCI) Epidemiology and Genomics Research Program (EGRP), extramural researchers, and other individuals, such as clinicians, community partners, and advocates, who are interested in cancer epidemiology and genomics.

  15. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  16. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  17. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  18. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  19. 14 CFR 25.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float design. 25.753 Section 25.753 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Floats and Hulls § 25.753 Main float...

  20. 14 CFR 25.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 25.753 Section 25.753 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Floats and Hulls § 25.753 Main float...

  1. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... follows: EC28SE91.043 where— ρ=mass density of water (slugs/ft.2); V=volume of float (ft.2); C x... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.535 Auxiliary float loads. (a..., the prescribed water loads may be distributed over the float bottom to avoid excessive local...

  2. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... follows: EC28SE91.043 where— ρ=mass density of water (slugs/ft.2); V=volume of float (ft.2); C x... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.535 Auxiliary float loads. (a..., the prescribed water loads may be distributed over the float bottom to avoid excessive local...

  3. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... follows: EC28SE91.043 where— ρ=mass density of water (slugs/ft.2); V=volume of float (ft.2); C x... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.535 Auxiliary float loads. (a..., the prescribed water loads may be distributed over the float bottom to avoid excessive local...

  4. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... follows: EC28SE91.043 where— ρ=mass density of water (slugs/ft.2); V=volume of float (ft.2); C x... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.535 Auxiliary float loads. (a..., the prescribed water loads may be distributed over the float bottom to avoid excessive local...

  5. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... follows: EC28SE91.043 where— ρ=mass density of water (slugs/ft.2); V=volume of float (ft.2); C x... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.535 Auxiliary float loads. (a..., the prescribed water loads may be distributed over the float bottom to avoid excessive local...

  6. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Life floats and buoyant apparatus. 131.870 Section 131... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant...

  7. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Life floats and buoyant apparatus. 131.870 Section 131... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant...

  8. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Life floats and buoyant apparatus. 131.870 Section 131... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant...

  9. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant apparatus... 46 Shipping 4 2010-10-01 2010-10-01 false Life floats and buoyant apparatus. 131.870 Section...

  10. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant apparatus... 46 Shipping 4 2011-10-01 2011-10-01 false Life floats and buoyant apparatus. 131.870 Section...

  11. Gap Balanced Total Knee Arthroplasty

    MedlinePlus

    Gap Balanced Total Knee Arthroplasty – SIGMA® with AOX™ You must have Javascript enabled in your web browser. View Program Transcript Click Here to view the OR-Live, Inc. Privacy Policy and Legal Notice © 2010 OR-Live, Inc. All rights reserved.

  12. Petriellidium boydii infection of knee

    SciTech Connect

    Kemp, H.B.S.; Bedford, A.F.; Fincham, W.J.

    1982-12-01

    A case of Petriellidium boydii (synonym: Allescheria boydii) infection of the knee joint is described. It followed a penetrating soft tissue injury with a pitchfork. Such infections are rare in this country and bone involvement has not been recorded previously except in maduramycosis contracted in tropical areas.

  13. Knee joint replacement prosthesis (image)

    MedlinePlus

    A prosthesis is a device designed to replace a missing part of the body, or to make a part of the body work better. The metal prosthetic device in knee joint replacement surgery replaces cartilage and bone which is damaged from disease or aging.

  14. The Meniscus-Deficient Knee

    PubMed Central

    Rao, Allison J.; Erickson, Brandon J.; Cvetanovich, Gregory L.; Yanke, Adam B.; Bach, Bernard R.; Cole, Brian J.

    2015-01-01

    Meniscal tears are the most common knee injury, and partial meniscectomies are the most common orthopaedic surgical procedure. The injured meniscus has an impaired ability to distribute load and resist tibial translation. Partial or complete loss of the meniscus promotes early development of chondromalacia and osteoarthritis. The primary goal of treatment for meniscus-deficient knees is to provide symptomatic relief, ideally to delay advanced joint space narrowing, and ultimately, joint replacement. Surgical treatments, including meniscal allograft transplantation (MAT), high tibial osteotomy (HTO), and distal femoral osteotomy (DFO), are options that attempt to decrease the loads on the articular cartilage of the meniscus-deficient compartment by replacing meniscal tissue or altering joint alignment. Clinical and biomechanical studies have reported promising outcomes for MAT, HTO, and DFO in the postmeniscectomized knee. These procedures can be performed alone or in conjunction with ligament reconstruction or chondral procedures (reparative, restorative, or reconstructive) to optimize stability and longevity of the knee. Complications can include fracture, nonunion, patella baja, compartment syndrome, infection, and deep venous thrombosis. MAT, HTO, and DFO are effective options for young patients suffering from pain and functional limitations secondary to meniscal deficiency. PMID:26779547

  15. Phaeohyphomycosis infection in the knee.

    PubMed

    Sadigursky, David; Nogueira E Ferreira, Luisa; Moreno de Oliveira Corrêa, Liz

    2016-01-01

    Phaeohyphomycosis is caused by cutaneous fungi and rarely affects large joints. This is a case report on phaeohyphomycosis in the left knee of an elderly individual without immunosuppression. It was accompanied by pain and swelling the anterior knee. The case was first suspected to be suprapatellar bursitis, and was treated with nonsteroidal anti-inflammatory drugs, without remission of symptoms. Surgical treatment was performed, with resection of the suprapatellar bursa and anterior region of the quadriceps tendon. The material was sent for anatomopathological examination and culturing. The pathological examination showed phaeohyphomycosis. The treatment instituted consisted of itraconazole, 200 mg/day for six weeks, and complete remission of symptoms was achieved. The physical examination remained normal after one year of follow-up. This is the first published case of phaeohyphomycosis infection in the suprapatellar region of the knee. Although almost all the cases reported have been associated with immunosuppressed patients, this was an exception. It is important to suspect phaeohyphomycosis in cases of knee infection, in the area of the suprapatellar bursa, when the symptoms do not resolve after clinical treatment. PMID:27069894

  16. Revision of the Gunston polycentric knee arthroplasty with total knee arthroplasty.

    PubMed

    Memişoğlu, Kaya; Müezzinoğlu, U Sefa; Kesemenli, Cumhur Cevdet

    2010-01-01

    The Gunston polycentric knee arthroplasty, first designed and performed by Frank Gunston in 1971, is the first prosthesis considering the natural knee biomechanics. Although the polycentric knee arthroplasty showed encouraging results to relieve pain and to preserve the preoperative range of motion and joint instability, the improvements in prosthesis design and arthroplasty technology rapidly made the polycentric knee prosthesis obsolete. Herein, we report a 58-year old male patient who had revision of the Gunston polycentric knee arthroplasty with total knee arthroplasty performed 32 years after the initial operation. PMID:21343693

  17. Floating--A Key to Survival.

    ERIC Educational Resources Information Center

    Anderson, Norman

    1980-01-01

    Described are several activities to be used to help students grasp the concept of floating. The activities include the use of a spring scale to measure the weight of the objects in air, in water, and in salt water, and a discussion of why there are differences in these weights. (DS)

  18. Subtropical Productivity from Profiling Floats and Gliders

    NASA Astrophysics Data System (ADS)

    Nicholson, D. P.; Johnson, K. S.; Karl, D. M.

    2015-12-01

    Since 2007 profiling floats equipped with dissolved oxygen and nitrate sensors have been released from the Hawaii Ocean Time-series (HOT) and Bermuda Atlantic Time-series Study (BATS) sites and can be calibrated using time-series observations. More recent deployments have also included bio-optical and pH sensors. Gliders with oxygen sensors and bio-optics have been intermittently deployed near HOT Station ALOHA since 2008 and at BATS since 2014. While gliders maintain a restricted survey region near the time-series stations, profiling floats drifted widely across the subtropical gyres. Multiple floats and gliders enables a cotemporaneous comparison of biogeochemical processes across gyres. These platforms enable observations on spatial scales from submesoscale to basin scale and on temporal scales from diel to interannual. Here, I focus on the spatiotemporal variability of nitrate and oxygen mass balances in the North Pacific and North Atlantic subtropical gyres using a data-assimilating and float-tracking 1D upper ocean model.

  19. Genetics Home Reference: Floating-Harbor syndrome

    MedlinePlus

    ... Arpin S, Afenjar A, Dubern B, Toutain A, Cabrol S, Héron D. Floating-Harbor Syndrome: report on a case ... G, Whiteford ML, Quaio CR, Gomy I, Bertola DR, Albrecht B, Platzer K, McGillivray G, Zou R, ...

  20. Dealing with Human Death: The Floating Perspective.

    ERIC Educational Resources Information Center

    Kenyon, Gary M.

    1991-01-01

    Explores approach to dealing with human death. Describes floating perspective, based on insights from Choron and Jaspers, as suggesting it is possible to deal with human death by refraining from taking ultimate position on the problem. Position encourages openness to death. Examines role of anxiety and describes possible meaningful outcomes of…

  1. Editorial Commentary: Platelet-Rich Plasma Improves Knee Pain and Function in Patients With Knee Osteoarthritis.

    PubMed

    Lubowitz, James H

    2015-11-01

    Systematic review of overlapping meta-analyses shows that platelet-rich plasma improves knee pain and function in patients with knee osteoarthritis. Ultimately, biologics hold promise for chondroprotection in addition to symptomatic relief. PMID:26542203

  2. Total Knee Replacement as a Knee Osteoarthritis Outcome

    PubMed Central

    Raynauld, Jean-Pierre; Martel-Pelletier, Johanne; Dorais, Marc; Haraoui, Boulos; Choquette, Denis; Abram, François; Beaulieu, André; Bessette, Louis; Morin, Frédéric; Wildi, Lukas M.

    2013-01-01

    Objective. To predict, using clinical and qMRI data, the incidence of total knee replacement (TKR) during the long-term follow-up of knee osteoarthritis (OA) patients who formerly received chondroitin sulfate (CS) or placebo treatment. Design. A post hoc intention-to-treat analysis to evaluate the incidence of TKR was done on knee OA patients who had participated in a 12-month trial evaluating the impact of CS (800 mg/d) versus placebo for 6 months, followed by a 6-month open-phase in which all patients received CS. Additionally, the clinical and qMRI predictors of TKR were determined. Results. Thirteen TKRs were performed in the population after a 4-year follow-up. More TKRs were performed in the placebo group than in the CS group (69% vs. 31%, P = 0.150, logistic regression). The statistically significant predictors of TKRs were, at baseline, higher WOMAC pain and function scores, presence of bone marrow lesions (BMLs), and higher C-reactive protein levels. Loss of medial cartilage volume and increase in WOMAC pain and function at one-year were also predictors of TKR. Multivariate analyses revealed that baseline presence of BML and higher WOMAC pain score were independent predictors. Time to occurrence of the TKR also favored the CS group versus placebo (log-rank, P = 0.094). Conclusion. Symptoms such as knee pain and function, presence of BML, and cartilage volume loss predict the long-term occurrence of a “hard” outcome such as TKR. PMID:26069668

  3. Adjustable hinge permits movement of knee in plaster cast

    NASA Technical Reports Server (NTRS)

    Maley, W. E.

    1967-01-01

    Metal knee hinge with an adjustable sleeve worn on the outside of a leg cast facilitates movement of the knee joint. This helps eliminate stiffness of the knee and eliminates bulkiness and adjustment difficulty.

  4. [Is knee osteotomy still indicated in knee osteoarthritis?].

    PubMed

    Antonescu, D N

    2000-12-01

    This study was undertaken to investigate whether high tibial osteotomy (HTO) still had a role in the treatment of osteoarthritis of the knee joint. The author has performed photoelasticity studies which confirmed abnormal stress distribution over the joint, as soon as its mechanical axis was deviated and the joint line had an obliquity over 10 degrees. High tibial osteotomy to correct varus or valgus deformity restores a symmetrical stress distribution and represents the only etiological treatment of secondary osteoarthritis of the knee. Two hundred and fifty HTO's were performed between 1971 and 1985 for osteoarthritis of the knee. The short-term result was good or very good in 75%, fair in 20% and poor in 5%. Fair and poor results were related to insufficient correction, to infection or mostly to incorrect indications. In 152 cases with a good or very good short term result, a further evaluation was made between 8 years and 15 years after operation. It was noted that osteoarthritis had been arrested in 105 cases (69%) whereas it had deteriorated in 47 cases. The main factors associated with further deterioration were insufficient correction and persistence of joint line obliquity. Provided on optimal correction is achieved (3 degrees to 6 degrees hypercorrection in valgus osteotomy, 0 degree in varus osteotomy) and provided a horizontal joint line is restored, HTO performed in good indications (Ahlback grade I or II) may provide good results for at least 10 to 15 years. PMID:11196365

  5. Anterior knee pain following primary total knee arthroplasty

    PubMed Central

    Shervin, David; Pratt, Katelyn; Healey, Travis; Nguyen, Samantha; Mihalko, William M; El-Othmani, Mouhanad M; Saleh, Khaled J

    2015-01-01

    Despite improvements in technique and technology for total knee arthroplasty (TKA), anterior knee pain impacts patient outcomes and satisfaction. Addressing the prosthetic and surgical technique related causes of pain after TKA, specifically as it relates to anterior knee pain, can aid surgeons in addressing these issues with their patients. Design features of the femoral and patellar components which have been reported as pain generators include: Improper femoral as well as patellar component sizing or designs that result in patellofemoral stuffing; a shortened trochlear groove distance from the flange to the intercondylar box; and then surgical technique related issues resulting in: Lateral patellar facet syndrome; overstuffed patella/flange combination; asymmetric patellar resurfacing, improper transverse plane component rotation resulting in patellar subluxation/tilt. Any design consideration that allows impingement of extensor mechanism anatomical elements has the possibility of impacting outcome by becoming a pain generator. As the number of TKA procedures continues to increase, it is increasingly critical to develop improved, evidence based prostheses that maximize function and patient satisfaction while minimizing pain and other complications. PMID:26601061

  6. Parasitic diseases of marine fish: epidemiological and sanitary considerations.

    PubMed

    Fioravanti, M L; Caffara, M; Florio, D; Gustinelli, A; Marcer, F; Quaglio, F

    2006-06-01

    Over recent decades, parasitic diseases have been increasingly considered a sanitary and economic threat to Mediterranean aquaculture. In order to monitor the distribution of parasites in cultured marine fish from Italy and study their pathogenic effects on the host, a three-year survey based on parasitological and histopathological exams was carried out on 2141 subjects from eleven fish species and coming from different farming systems (extensive, intensive inland farms, inshore floating cages, offshore floating cages and submersible cages). A number of parasitic species was detected, mostly in European sea bass (Dicentrarchus labrax), gilthead sea bream (Sparus aurata), mullets (Chelon labrosus, Mugil cephalus, Liza ramada) and sharpsnout sea bream (Diplodus puntazzo), with distribution patterns and prevalence values varying in relation to the farming system, in-season period and size category. The epidemiology and pathological effects of the parasites found during the survey are discussed. PMID:16881387

  7. A prosthetic knee using magnetorhelogical fluid damper for above-knee amputees

    NASA Astrophysics Data System (ADS)

    Park, Jinhyuk; Choi, Seung-Bok

    2015-04-01

    A prosthetic knee for above-knee (AK) amputees is categorized into two types; namely a passive and an active type. The passive prosthetic knee is generally made by elastic materials such as carbon fiber reinforced composite material, titanium and etc. The passive prosthetic knee easy to walk. But, it has disadvantages such that a knee joint motion is not similar to ordinary people. On the other hand, the active prosthetic knee can control the knee joint angle effectively because of mechanical actuator and microprocessor. The actuator should generate large damping force to support the weight of human body. But, generating the large torque using small actuator is difficult. To solve this problem, a semi-active type prosthetic knee has been researched. This paper proposes a semi-active prosthetic knee using a flow mode magneto-rheological (MR) damper for AK amputees. The proposed semi-active type prosthetic knee consists of the flow mode MR damper, hinge and prosthetic knee body. In order to support weight of human body, the required energy of MR damper is smaller than actuator of active prosthetic leg. And it can control the knee joint angle by inducing the magnetic field during the stance phase.

  8. How does knee pain affect trunk and knee motion during badminton forehand lunges?

    PubMed

    Huang, Ming-Tung; Lee, Hsing-Hsan; Lin, Cheng-Feng; Tsai, Yi-Ju; Liao, Jen-Chieh

    2014-01-01

    Badminton requires extensive lower extremity movement and a precise coordination of the upper extremity and trunk movements. Accordingly, this study investigated motions of the trunk and the knee, control of dynamic stability and muscle activation patterns of individuals with and without knee pain. Seventeen participants with chronic knee pain and 17 healthy participants participated in the study and performed forehand forward and backward diagonal lunges. This study showed that those with knee pain exhibited smaller knee motions in frontal and horizontal planes during forward lunge but greater knee motions in sagittal plane during backward lunge. By contrast, in both tasks, the injured group showed a smaller value on the activation level of the paraspinal muscles in pre-impact phase, hip-shoulder separation angle, trunk forward inclination range and peak centre of mass (COM) velocity. Badminton players with knee pain adopt a more conservative movement pattern of the knee to minimise recurrence of knee pain. The healthy group exhibit better weight-shifting ability due to a greater control of the trunk and knee muscles. Training programmes for badminton players with knee pain should be designed to improve both the neuromuscular control and muscle strength of the core muscles and the knee extensor with focus on the backward lunge motion. PMID:24404882

  9. The Attenborough total knee replacement.

    PubMed

    Attenborough, C G

    1978-08-01

    The stabilised gliding knee prosthesis is a compromise between hinged joints and condylar prostheses. It is a two-piece implant designed to allow normal gliding movements of flexion and extension and which, stabilised by a connecting rod between the femoral and tibial components, allows a designed laxity of rotation and lateral movements. A modification of the original femoral component is described. Two hundred and forty-five knee replacement operations have been done between January 1973 and September 1977 and the results are reported. The results using this prosthesis are at least equal to those using hinged or condylar prostheses. So far there has been no case of spontaneous loosening of the components and the implant can be used in patients who, because of severe deformities and instability, are unsuitable for condylar prostheses. PMID:681407

  10. OCD metrology by floating n/k

    NASA Astrophysics Data System (ADS)

    Yu, Shinn-Sheng; Huang, Jacky; Ke, Chih-Ming; Gau, Tsai-Sheng; Lin, Burn J.; Yen, Anthony; Lane, Lawrence; Vuong, Vi; Chen, Yan

    2007-03-01

    In this paper, one of the major contributions to the OCD metrology error, resulting from within-wafer variation of the refractive index/extinction coefficient (n/k) of the substrate, is identified and quantified. To meet the required metrology accuracy for the 65-nm node and beyond, it is suggested that n/k should be floating when performing the regression for OCD modeling. A feasible way of performing such regression is proposed and verified. As shown in the presented example, the measured CDU (3σ) with n/k fixed and n/k floating is 1.94 nm and 1.42 nm, respectively. That is, the metrology error of CDU committed by assuming n/k fixed is more than 35% of the total CDU.

  11. Electrodynamic convection in silicon floating zones

    NASA Astrophysics Data System (ADS)

    Mühlbauer, A.; Erdmann, W.; Keller, W.

    1983-12-01

    Using a simplified Navier-Stokes equation it has been possible to compute the electrodynamic convection generated by a radio frequency coil field for the modern needle-eye float-zone growth of silicon. The calculated electrodynamic force in such a zone shows maximum values up to 11.7 N/cm 3 and generates flow velocities between 25 and 100 cm/s. As only superficial convection can be brought about by electrodynamic forces, the axial and radial dopant incorporation will not be influenced strongly. A comparison of electrodynamic forces with the other forces possibly causing flow in silicon floating zones shows that the electrodynamic forces exceed all other forces by several orders of magnitude.

  12. Cryotherapy impairs knee joint position sense.

    PubMed

    Oliveira, R; Ribeiro, F; Oliveira, J

    2010-03-01

    The effects of cryotherapy on joint position sense are not clearly established; however it is paramount to understand its impact on peripheral feedback to ascertain the safety of using ice therapy before resuming exercise on sports or rehabilitation settings. Thus, the aim of the present study was to determine the effects of cryotherapy, when applied over the quadriceps and over the knee joint, on knee position sense. This within-subjects repeated-measures study encompassed fifteen subjects. Knee position sense was measured by open kinetic chain technique and active positioning at baseline and after cryotherapy application. Knee angles were determined by computer analysis of the videotape images. Twenty-minute ice bag application was applied randomly, in two sessions 48 h apart, over the quadriceps and the knee joint. The main effect for cryotherapy application was significant (F (1.14)=7.7, p=0.015) indicating an increase in both absolute and relative angular errors after the application. There was no significant main effect for the location of cryotherapy application, indicating no differences between the application over the quadriceps and the knee joint. In conclusion, cryotherapy impairs knee joint position sense in normal knees. This deleterious effect is similar when cryotherapy is applied over the quadriceps or the knee joint. PMID:20221997

  13. Relationships of Fear, Anxiety, and Depression With Physical Function in Patients With Knee Osteoarthritis

    PubMed Central

    Scopaz, Kristen A.; Piva, Sara R.; Wisniewski, Stephen; Fitzgerald, G. Kelley

    2016-01-01

    Objectives To explore whether the psychologic variables anxiety, depression, and fear-avoidance beliefs, and interactions between these variables, are associated with physical function in patients with knee osteoarthritis (OA). We hypothesized lower levels of function would be related to higher anxiety, higher depression, and higher fear-avoidance beliefs, and that high levels of 2 of these factors simultaneously might interact to have a greater adverse effect on physical function. Design Cross-sectional, correlational design. Setting Institutional practice. Participants Subjects included patients with knee OA (N=182; age, mean ± SD, 63.9±8.8y; 122 women). Interventions Not applicable. Main Outcome Measures Self-report measures of function included the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, the Lower Extremity Function Scale (LEFS), and the Knee Outcome Survey-Activity of Daily Living Scale. The Get Up and Go test was used as a physical performance measure of function. Self-report measures for psychologic variables included the Beck Anxiety Inventory, the Center for Epidemiological Studies Depression Scale, and the Fear Avoidance Belief Questionnaire-Physical Activity Scale modified for the knee. Results Higher anxiety was related to poorer function on the WOMAC physical function. Both high anxiety and fear avoidance beliefs were related to poorer function on the LEFS and Knee Outcome Survey-Activity of Daily Living Scale. There was no association between the psychologic variables and the Get Up and Go test. The anxiety X depression interaction was associated with the LEFS. Conclusions Anxiety and fear-avoidance beliefs are associated with self-report measures of function in patients with knee OA. Depression may influence scores on the LEFS under conditions of low anxiety. PMID:19887210

  14. Imaging following acute knee trauma.

    PubMed

    Kijowski, R; Roemer, F; Englund, M; Tiderius, C J; Swärd, P; Frobell, R B

    2014-10-01

    Joint injury has been recognized as a potent risk factor for the onset of osteoarthritis. The vast majority of studies using imaging technology for longitudinal assessment of patients following joint injury have focused on the injured knee joint, specifically in patients with anterior cruciate ligament injury and meniscus tears where a high risk for rapid onset of post-traumatic osteoarthritis is well known. Although there are many imaging modalities under constant development, magnetic resonance (MR) imaging is the most important instrument for longitudinal monitoring after joint injury. MR imaging is sensitive for detecting early cartilage degeneration and can evaluate other joint structures including the menisci, bone marrow, tendons, and ligaments which can be sources of pain following acute injury. In this review, focusing on imaging following acute knee trauma, several studies were identified with promising short-term results of osseous and soft tissue changes after joint injury. However, studies connecting these promising short-term results to the development of osteoarthritis were limited which is likely due to the long follow-up periods needed to document the radiographic and clinical onset of the disease. Thus, it is recommended that additional high quality longitudinal studies with extended follow-up periods be performed to further investigate the long-term consequences of the early osseous and soft tissue changes identified on MR imaging after acute knee trauma. PMID:25278054

  15. Sonar location system for freely floating buoys

    NASA Astrophysics Data System (ADS)

    Bird, I. G.

    1983-05-01

    A rf interrogated sonar location system for freely floating buoys is described. The location of an array of up to three buoys may be determined on an almost continuous basis within a radius of 500 m from a shipboard monitoring station. Location accuracy of typically ±0.5 m at 200-m range, low cost, and ease of operation are the major features of the system.

  16. TVFMCATS. Time Variant Floating Mean Counting Algorithm

    SciTech Connect

    Huffman, R.K.

    1999-05-01

    This software was written to test a time variant floating mean counting algorithm. The algorithm was developed by Westinghouse Savannah River Company and a provisional patent has been filed on the algorithm. The test software was developed to work with the Val Tech model IVB prototype version II count rate meter hardware. The test software was used to verify the algorithm developed by WSRC could be correctly implemented with the vendor`s hardware.

  17. Floating vs flying: A propulsion energy comparison

    NASA Technical Reports Server (NTRS)

    Marbury, F.

    1975-01-01

    Floating craft are compared to those that fly. Drag/weight for floaters is shown to be proportional to v squared/L, while for flyers it is independent of size and speed. The transportation market will therefore assign airships to lower speeds than airplanes, and will favor large airship sizes. Drag of an airship is shown to be only 11 percent of submarine drag at equal displacement and speed, raising the possibility that airships can compete with some types of ships.

  18. Time Variant Floating Mean Counting Algorithm

    Energy Science and Technology Software Center (ESTSC)

    1999-06-03

    This software was written to test a time variant floating mean counting algorithm. The algorithm was developed by Westinghouse Savannah River Company and a provisional patent has been filed on the algorithm. The test software was developed to work with the Val Tech model IVB prototype version II count rate meter hardware. The test software was used to verify the algorithm developed by WSRC could be correctly implemented with the vendor''s hardware.

  19. Floating debris in the Mediterranean Sea.

    PubMed

    Suaria, Giuseppe; Aliani, Stefano

    2014-09-15

    Results from the first large-scale survey of floating natural (NMD) and anthropogenic (AMD) debris (>2 cm) in the central and western part of the Mediterranean Sea are reported. Floating debris was found throughout the entire study area with densities ranging from 0 to 194.6 items/km(2) and mean abundances of 24.9 AMD items/km(2) and 6.9 NMD items/km(2) across all surveyed locations. On the whole, 78% of all sighted objects were of anthropogenic origin, 95.6% of which were petrochemical derivatives (i.e. plastic and styrofoam). Maximum AMD densities (>52 items/km(2)) were found in the Adriatic Sea and in the Algerian basin, while the lowest densities (<6.3 items/km(2)) were observed in the Central Tyrrhenian and in the Sicilian Sea. All the other areas had mean densities ranging from 10.9 to 30.7 items/km(2). According to our calculations, more than 62 million macro-litter items are currently floating on the surface of the whole Mediterranean basin. PMID:25127501

  20. Capillary effects on floating cylindrical particles

    NASA Astrophysics Data System (ADS)

    Dixit, Harish N.; Homsy, G. M.

    2012-12-01

    In this study, we develop a systematic perturbation procedure in the small parameter, B1/2, where B is the Bond number, to study capillary effects on small cylindrical particles at interfaces. Such a framework allows us to address many problems involving particles on flat and curved interfaces. In particular, we address four specific problems: (i) capillary attraction between cylinders on flat interface, in which we recover the classical approximate result of Nicolson ["The interaction between floating particles," Proc. Cambridge Philos. Soc. 45, 288-295 (1949), 10.1017/S0305004100024841], thus putting it on a rational basis; (ii) capillary attraction and aggregation for an infinite array of cylinders arranged on a periodic lattice, where we show that the resulting Gibbs elasticity obtained for an array can be significantly larger than the two cylinder case; (iii) capillary force on a cylinder floating on an arbitrary curved interface, where we show that in the absence of gravity, the cylinder experiences a lateral force which is proportional to the gradient of curvature; and (iv) capillary attraction between two cylinders floating on an arbitrary curved interface. The present perturbation procedure does not require any restrictions on the nature of curvature of the background interface and can be extended to other geometries.

  1. Liquid encapsulated float zone process and apparatus

    NASA Technical Reports Server (NTRS)

    Naumann, Robert J. (Inventor); Frazier, Donald O. (Inventor); Lehoczky, Sandor L. (Inventor); Vlasse, Marcus (Inventor); Facemire, Barbara R. (Inventor)

    1988-01-01

    The process and apparatus for growing crystals using float zone techniques are described. A rod of crystalline materials is disposed in a cylindrical container, leaving a space between the rod and container walls. This space is filled with an encapsulant, selected to have a slightly lower melting point than the crystalline material. The rod is secured to a container end cap at one end and to a shaft at its other end. A piston slides over the rod and provides pressure to prevent loss of volatile components upon melting of the rod. Prior to melting the rod the container is first heated to melt the encapsulant, with any off-gas from this step being vented to a cavity behind the piston. The piston moves slightly forward owing to volume change upon melting of the encapsulant, and the vent passageway is closed. The container is then moved longitudinally through a heated zone to progressively melt sections of the rod as in conventional float zone processes. The float zone technique may be used in the microgravity environment of space.

  2. Borofloat and Starphire Float Glasses: A Comparison

    SciTech Connect

    Wereszczak, Andrew A.; Anderson Jr., Charles E.

    2014-10-28

    Borofloat® borosilicate float glass and Starphire® soda-lime silicate float glass are used in transparent protective systems. They are known to respond differently in some ballistic and triaxial loading conditions, and efforts are underway to understand the causes of those differences. Toward that, a suite of test and material characterizations were completed in the present study on both glasses so to identify what differences exist among them. Compositional, physical properties, elastic properties, flaw size distributions and concentrations, tensile/flexure strength, fracture toughness, spherical indentation and hardness, transmission electron microscopy, striae, high pressure responses via diamond anvil cell testing, laser shock differences, and internal porosity were examined. Differences between these two float glasses were identified for many of these properties and characteristics, and the role of three (striae, high pressures where permanent densification can initiate, and sub-micron-sized porosity) lack understanding and deserve further attention. Lastly, the contributing roles of any of those properties or characteristics to triaxial or ballistic loading responses are not definitive; however, they provide potential correlations that may lead to improved understanding and management of loading responses in glasses used in transparent protective systems.

  3. Borofloat and Starphire Float Glasses: A Comparison

    DOE PAGESBeta

    Wereszczak, Andrew A.; Anderson Jr., Charles E.

    2014-10-28

    Borofloat® borosilicate float glass and Starphire® soda-lime silicate float glass are used in transparent protective systems. They are known to respond differently in some ballistic and triaxial loading conditions, and efforts are underway to understand the causes of those differences. Toward that, a suite of test and material characterizations were completed in the present study on both glasses so to identify what differences exist among them. Compositional, physical properties, elastic properties, flaw size distributions and concentrations, tensile/flexure strength, fracture toughness, spherical indentation and hardness, transmission electron microscopy, striae, high pressure responses via diamond anvil cell testing, laser shock differences, andmore » internal porosity were examined. Differences between these two float glasses were identified for many of these properties and characteristics, and the role of three (striae, high pressures where permanent densification can initiate, and sub-micron-sized porosity) lack understanding and deserve further attention. Lastly, the contributing roles of any of those properties or characteristics to triaxial or ballistic loading responses are not definitive; however, they provide potential correlations that may lead to improved understanding and management of loading responses in glasses used in transparent protective systems.« less

  4. Drill vessels float in aerated water

    SciTech Connect

    Hammett, D.S.

    1985-01-01

    Model tests, calculations, and case studies prove that a floating vessel will not sink due to gas reducing the water density in or adjacent to a subsea blowout. Several floating drill vessels have been lost as a result of subsea blowouts. Reports have circulated that the rig sank into something similar to a hole in the ocean caused by gas bubbles suspended in the water reducing its specific gravity. These erroneous reports, believed as truth by many people, have resulted in the modification of operations resulting in decreased safety. Several subsea well control operations have caused accidents and losses because the riser was not disconnected. This action was taken in fear of sinking in aerated water. The losses occurred because the vessel winched itself off the drill site to get away from the subsea well before disconnecting. Due to the high riser/BOP angle, the riser could not be disconnected and well control was later lost and the gas/oil flowed directly to the rig floor where massive fire/explosion damage occurred. If there had been a better understanding of water density, the rig personnel could have closed all hatches, shut-down all engines, disconnected the riser and released mooring lines at one end of the rig, and safely removed the rig out of the aerated water. This paper presents some of the technical data and references available which prove that a floating vessel will not sink due to loss of water density.

  5. FPP [Floating Potential Probe] Results, Final Report

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.

    2007-01-01

    The Floating Potential Probe (FPP) operated on the International Space Station (ISS) from December 2000 to April 2001. During that time, it took many measurements of the ISS floating potential and the electron density and temperature. Those measurements were used as inputs to the Environments WorkBench (EWB) model of ISS potentials (originally developed by SAIC, but now sometimes called the Boeing model) that is used even today to predict charging levels for ISS. FPP is now completely defunct, having been removed and ejected from ISS. With the advent of the new Floating Potential Monitoring Unit (FPMU) on ISS, and the beginning of ISS operations with two large solar array panels instead of just one, a review of FPP measurements can offer comparisons with the new FPMU data and perhaps improve the accuracy of future ISS charging predictions. In particular, FPP measurements during times of low electron temperature and high electron density (the times of worst ISS charging) will be brought forward for comparison with the newly obtained FPMU data.

  6. Multiview autosterescopic display with floating real image

    NASA Astrophysics Data System (ADS)

    Kakeya, Hideki; Kobe, Naoto; Kasano, Hidehiro

    2004-05-01

    This paper proposes multiview version of autostereoscopic display FLOATS (Fresnel Lens based Optical Apparatus for Touchable-distance Stereoscopy), which combines generation of floating real image and parallax presentation to show realistic 3-D image within the viewer's reach. Earlier versions of FLOATS have required a head tracker, physical motion control of filters or mirrors, and transformation of image in accordance with the viewer's motion to keep on presenting different images to each eye. To do away with these requirements, we propose two methods which realize multiview presentation to the viewer. One method is to use multiple LCD panels and multiple fixed mirrors instead of mobile mirrors. The other method is to use mutiple projectors, fly-eye lenses, and fresnel lenses. Though the former system doesn't cost much, it is not practical to present more than 10 views. In the latter system it is practical to present more than 30 views, which can realize presentation of both horizontal and vertical parallax. With this technology the viewers can perceive undistorted 3-D space from any angle, which makes it possible for multiple viewers to observe 3-D image at consistent position from different angles at the same time.

  7. Knee motion variability in patients with knee osteoarthritis: the effect of self-reported instability

    PubMed Central

    Gustafson, Jonathan A.; Robinson, Megan E.; Fitzgerald, G. Kelley; Tashman, Scott; Farrokhi, Shawn

    2015-01-01

    Background Knee osteoarthritis has been previously associated with a stereotypical knee-stiffening gait pattern and reduced knee joint motion variability due to increased antagonist muscle co-contractions and smaller utilized arc of motion during gait. However, episodic self-reported instability may be a sign of excessive motion variability for a large subgroup of patients with knee osteoarthritis. The objective of this work was to evaluate the differences in knee joint motion variability during gait in patients with knee osteoarthritis with and without self-reported instability compared to a control group of older adults with asymptomatic knees. Methods Forty-three subjects, 8 with knee osteoarthritis but no reports of instability (stable), 11 with knee osteoarthritis and self-reported instability (unstable), and 24 without knee osteoarthritis or instability (control) underwent Dynamic Stereo X-ray analysis during a decline gait task on a treadmill. Knee motion variability was assessed using parametric phase plots during the loading response phase of decline gait. Findings The stable group demonstrated decreased sagittal-plane motion variability compared to the control group (p=0.04), while the unstable group demonstrated increased sagittal-plane motion variability compared to the control (p=0.003) and stable groups (p<0.001). The unstable group also demonstrated increased anterior-posterior joint contact point motion variability for the medial tibiofemoral compartment compared to the control (p=0.03) and stable groups (p=0.03). Interpretation The finding of decreased knee motion variability in patients with knee osteoarthritis without self-reported instability supports previous research. However, presence of self-reported instability is associated with increased knee motion variability in patients with knee osteoarthritis and warrants further investigation. PMID:25796536

  8. Varus Thrust and Knee Frontal Plane Dynamic Motion in Persons with Knee Osteoarthritis

    PubMed Central

    Chang, Alison H.; Chmiel, Joan S.; Moisio, Kirsten C.; Almagor, Orit; Zhang, Yunhui; Cahue, September; Sharma, Leena

    2013-01-01

    Objective Varus thrust visualized during walking is associated with a greater medial knee and an increased risk of medial knee osteoarthritis (OA) progression. Little is known about varus thrust presence determined by visual observation relates to quantitative gait kinematic We hypothesized that varus thrust presence is associated with greater knee frontal plane dynamic movement during the stance phase of gait. Methods Participants had knee OA in at least one knee. Trained examiners assessed participants for varus thrust presence during ambulation. Frontal plane knee motion during ambulation captured using external passive reflective markers and an 8-camera motion analysis system. To examine the cross-sectional relationship between varus thrust and frontal plane knee motion, used multivariable regression models with the quantitative motion measures as dependent variables and varus thrust (present/absent) as predictor; models were adjusted for age, gender, BMI, gait speed, and knee static alignment. Results 236 persons [mean BMI: 28.5 kg/m2 (SD 5.5), mean age: 64.9 years (SD 10.4), 75.8% women] contributing 440 knees comprised the study sample. 82 knees (18.6%) had definite varus thrust. Knees with varus thrust had greater peak varus angle and greater peak varus angular velocity during stance than knees without varus thrust (mean differences 0.90° and 6.65°/sec, respectively). These patterns remained significant after adjusting for age, gender, BMI, gait speed, and knee static alignment. Conclusion Visualized varus thrust during walking was associated with a greater peak knee varus angular velocity and a greater peak knee varus angle during stance phase of gait. PMID:23948980

  9. Osteoarthritis and meniscus disorders of the knee as occupational diseases of miners

    PubMed Central

    McMillan, G; Nichols, L

    2005-01-01

    Aim: To determine whether kneeling or squatting for prolonged periods is sufficiently causally associated with an increased risk of injury or degenerative disease of the knee joint as to meet the classic criteria to be considered an occupational disease of coal miners for whom these are or have been routine working postures. Method: Systematic literature searches were made for studies relating to kneeling and squatting as part of the working environment of coal mines and the role of these postures in causation of knee disorders in coal miners, analogous occupations, populations, and communities. The working environment and potentially damaging forces on the knee when kneeling or squatting were described. Papers on the incidence or prevalence of knee disorders in occupational and other groups were scored against five criteria independently by each author, and from this a single consensus score representing the overall strength of evidence given by the research was awarded. The evidence was then weighed against the criteria for an occupational disease. Results: Nineteen published papers were scored, the majority of which focussed on osteoarthritis as the outcome of interest. Few of the studies found focussed specifically on miners, and those that did tended to involve small numbers of subjects and were carried out before 1960, when the mining population was at its largest but epidemiological evidence of the risk factors for knee disorders was not well established. The non-mining studies in the review represent groups of workers with a similar or lesser kneeling content in their work. Conclusion: The papers reviewed provide sufficient evidence to conclude that work involving kneeling and/or squatting is causally associated with an increased risk of osteoarthritis of the knee. In some of the more recent epidemiologically sound studies, frequent or prolonged kneeling or squatting doubles the general risk of osteoarthritis of the knees found in the general population

  10. Floating Oil-Spill Containment Device

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    2012-01-01

    Previous oil containment booms have an open top that allows natural gas to escape, and have significant oil leakage due to wave action. Also, a subsea pyramid oil trap exists, but cannot move relative to moving oil plumes from deepsea oil leaks. The solution is to have large, moveable oil traps. One version floats on the sea surface and has a flexible tarp cover and a lower weighted skirt to completely entrap the floating oil and natural gas. The device must have at least three sides with boats pulling at each apex, and sonar or other system to track the slowly moving oil plume, so that the boats can properly locate the booms. The oil trap device must also have a means for removal of the oil and the natural gas. A second design version has a flexible pyramid cover that is attached by lines to ballast on the ocean floor. This is similar to fixed, metal pyramid oil capture devices in the Santa Barbara Channel off the coast of California. The ballast lines for the improved design, however, would have winches that can move the pyramid to always be located above the oil and gas plume. A third design is a combination of the first two. It uses a submerged pyramid to trap oil, but has no anchor and uses boats to locate the trap. It has ballast weights located along the bottom of the tarp and/or at the corners of the trap. The improved floating oil-spill containment device has a large floating boom and weighted skirt surrounding the oil and gas entrapment area. The device is triangular (or more than three sides) and has a flexible tarp cover with a raised gas vent area. Boats pull on the apex of the triangles to maintain tension and to allow the device to move to optimum locations to trap oil and gas. The gas is retrieved from a higher buoyant part of the tarp, and oil is retrieved from the floating oil layer contained in the device. These devices can be operated in relatively severe weather, since waves will break over the devices without causing oil leaking. Also, natural

  11. Below Knee Impact Responses using Cadaveric Specimens.

    PubMed

    Balasubramanian, Sriram; Beillas, Philippe; Belwadi, Aditya; Hardy, Warren N; Yang, King H; King, Albert I; Masuda, Mitsutoshi

    2004-11-01

    Knee injuries represent about 10% of all injuries suffered during car crashes. Efforts to assess the injury risk to the posterior cruciate ligament (PCL) have been based on a study available in the literature (Viano et al., 1978), in which only two of the five knees tested had PCL ruptures. The aims of the current study were to repeat the study with a higher number of samples, study the effects of other soft tissues on knee response, and assess the adequacy of the experimental setup for the identification of a PCL tolerance. A total of 14 knees were tested using a high-speed materials testing machine. Eight were intact knees (with the patella and all the muscular and ligamentous structures), three were PCL-only knees (patella and all the muscular and ligamentous structures other than the PCL removed), and the last three were PCL-only knees with the tibia protected from bending fracture. Of the eight intact knees tested, only one had PCL mid substance rupture, one had a partial articular fracture of the tibia below the plateau, and six had simple transverse fracture of the tibial metaphysis. Of the three PCL-only knees without tibial protection, one had PCL mid substance rupture, one had avulsion at the posterior intercondylar attachment point, and the last one had a simple oblique fracture of the tibial metaphysis. Of the three PCL only knees with tibia protection, two had PCL mid-substance ruptures and the third one had an avulsion at the tibial insertion site with partial articular fracture of the lateral plateau. Overall, the results of the current study were similar to those observed by Viano et al. (1978). The average displacement at failure for all PCL related injuries was 17.2+/-2.8 mm for the current study (n=6) and 16.2+/-3.9 mm for Viano et al. (1978) (n=4). This value is higher than the Injury Assessment Reference Value of 15 mm proposed by Mertz (1984) and used in various regulations. Both studies suggest that the existence of the soft tissues other

  12. Float processing of high-temperature complex silicate glasses and float baths used for same

    NASA Technical Reports Server (NTRS)

    Cooper, Reid Franklin (Inventor); Cook, Glen Bennett (Inventor)

    2000-01-01

    A float glass process for production of high melting temperature glasses utilizes a binary metal alloy bath having the combined properties of a low melting point, low reactivity with oxygen, low vapor pressure, and minimal reactivity with the silicate glasses being formed. The metal alloy of the float medium is exothermic with a solvent metal that does not readily form an oxide. The vapor pressure of both components in the alloy is low enough to prevent deleterious vapor deposition, and there is minimal chemical and interdiffusive interaction of either component with silicate glasses under the float processing conditions. Alloys having the desired combination of properties include compositions in which gold, silver or copper is the solvent metal and silicon, germanium or tin is the solute, preferably in eutectic or near-eutectic compositions.

  13. The knee-spine syndrome. Association between lumbar lordosis and extension of the knee.

    PubMed

    Murata, Yasuaki; Takahashi, Kazuhisa; Yamagata, Masatsune; Hanaoka, Eiji; Moriya, Hideshige

    2003-01-01

    Degenerative changes of the knee often cause loss of extension. This may affect aspects of posture such as lumbar lordosis. A total of 366 patients underwent radiological examination of the lumbar spine in a standing position. The knee and body angles were measured by physical examination using a goniometer. Limitation of extension of the knee was significantly greater in patients whose lumbar lordosis was 30 degrees or less. Lumbar lordosis was significantly reduced in patients whose limitation of extension of the knee was more than 5 degrees. It decreased over the age of 70 years, and the limitation of extension of the knee increased over the age of 60 years. Our study indicates that symptoms from the lumbar spine may be caused by degenerative changes in the knee. This may be called the 'knee-spine syndrome'. PMID:12585585

  14. Arthroscopic knee debridement can delay total knee replacement in painful moderate haemophilic arthropathy of the knee in adult patients.

    PubMed

    Rodriguez-Merchan, E Carlos; Gomez-Cardero, Primitivo

    2016-09-01

    The role of arthroscopic debridement of the knee in haemophilia is controversial in the literature. The purpose of this study is to describe the results of arthroscopic knee debridement (AKD), with the aim of determining whether it is possible to delay total knee replacement (TKR) for painful moderate haemophilic arthropathy of the knee in adult patients. In a 14-year period (1998-2011), AKD was performed for moderate haemophilic arthropathy of the knee in 27 patients with haemophilia A. Their average age at operation was 28.6 years (range 26-39 years). Indications for surgery were as follows: more than 90° of knee flexion, flexion deformity less than 30°, good axial alignment of the knee, good patellar alignment, and pain above >60 points in a visual analogue scale [0 (no pain) to 100 points]. Secondary haematological prophylaxis and rehabilitation (physiotherapy) was given for at least 3 months after surgery. Follow-up was for an average of 7.5 years (range 2-14 years). We assessed the clinical outcome before surgery and at the time of latest follow-up using the Knee Society pain and function scores, the range of motion, and the radiological score of the World Federation of Haemophilia. Knee Society pain scores improved from 39 preoperatively to 66 postoperatively, and function scores improved from 36 to 52. Range of motion improved on an average from -15° of extension and 90° of flexion before surgery, to -5° of extension and 110° of flexion at the last follow-up. A radiological deterioration of 2.8 points on average was found. There were two (7.4%) postoperative complications (haemarthroses resolved by joint aspiration). One patient (3.7%) required a TKR 12.5 years later. AKD should be considered in painful moderate haemophilic arthropathy of the knee in adult patients to delay TKR. PMID:26575489

  15. KNEE-JOINT LOADING IN KNEE OSTEOARTHRITIS: INFLUENCE OF ABDOMINAL AND THIGH FAT

    PubMed Central

    Messier, Stephen P.; Beavers, Daniel P.; Loeser, Richard F.; Carr, J. Jeffery; Khajanchi, Shubham; Legault, Claudine; Nicklas, Barbara J.; Hunter, David J.; DeVita, Paul

    2014-01-01

    Purpose Using three separate models that included total body mass, total lean and total fat mass, and abdominal and thigh fat as independent measures, we determined their association with knee-joint loads in older overweight and obese adults with knee osteoarthritis (OA). Methods Fat depots were quantified using computed tomography and total lean and fat mass determined with dual energy x-ray absorptiometry in 176 adults (age = 66.3 yr., BMI = 33.5 kg·m−2) with radiographic knee OA. Knee moments and joint bone-on-bone forces were calculated using gait analysis and musculoskeletal modeling. Results Higher total body mass was significantly associated (p ≤ 0.0001) with greater knee compressive and shear forces, compressive and shear impulses (p < 0.0001), patellofemoral forces (p< 0.006), and knee extensor moments (p = 0.003). Regression analysis with total lean and total fat mass as independent variables revealed significant positive associations of total fat mass with knee compressive (p = 0.0001), shear (p < 0.001), and patellofemoral forces (p = 0.01) and knee extension moment (p = 0.008). Gastrocnemius and quadriceps forces were positively associated with total fat mass. Total lean mass was associated with knee compressive force (p = 0.002). A regression model that included total thigh and total abdominal fat found both were significantly associated with knee compressive and shear forces (p ≤ 0.04). Thigh fat was associated with the knee abduction (p = 0.03) and knee extension moment (p = 0.02). Conclusions Thigh fat, consisting predominately of subcutaneous fat, had similar significant associations with knee joint forces as abdominal fat despite its much smaller volume and could be an important therapeutic target for people with knee OA. PMID:25133996

  16. A rare variant of knee dislocation

    PubMed Central

    HUSSIN, P.; MAWARDI, M.; AB HALIM, A.H.

    2016-01-01

    Knee dislocation is a rare injury. It represents less than 0.2% of orthopaedic injuries. This case reports a rare form of knee dislocation caused by the impact of a high-energy trauma. In these cases the appropriate assessment and management is needed to ensure that patient receives the proper treatment. PMID:27381692

  17. Knee Braces to Prevent Injuries in Football.

    ERIC Educational Resources Information Center

    Physician and Sportsmedicine, 1986

    1986-01-01

    Five physicians discuss the use of knee braces to prevent injuries in football players. Questions are raised regarding the strength and design of the braces, whether they prestress the knee in some cases, and whether they actually reduce injuries. More clinical and biomechanical research is called for. (MT)

  18. Jumper's Knee (Patellar Tendonitis) (For Parents)

    MedlinePlus

    ... regularly play sports that involve a lot of repetitive jumping — like track and field (particularly high-jumping), basketball, volleyball, gymnastics, running, and soccer — can put a lot of strain on their knees. Jumper's knee can seem like a minor injury that isn't really that serious. Because of ...

  19. Design characteristics of pediatric prosthetic knees.

    PubMed

    Andrysek, Jan; Naumann, Stephen; Cleghorn, William L

    2004-12-01

    We examined whether pediatric prosthetic single-axis knees can theoretically provide the beneficial functional characteristics of polycentric knees and the design considerations needed to realize this. Five children and their parents provided subjective opinions of the relative importance of functional requirements (FRs) for the knee. FRs related to comfort, fatigue, stability, and falling were found to be of high importance, while sitting appearance and adequate knee flexion were of lower importance. Relationships were drawn between these FRs and deductions were made regarding the importance of associated design parameters. Stance-phase control was rated to be of greatest importance followed by toe clearance. Models were developed for five knees including four- and six-bar knees, corresponding to two commercially available components, and for three configurations of a single-axis knee. Stance-phase control, specifically stability after heel-strike and swing-phase initiation at push-off, and toe clearance were simulated. The results suggest that a single-axis knee design incorporating stance-phase control will mutually satisfy the identified set of highly and moderately important FRs. PMID:15614992

  20. Current Surgical Treatment of Knee Osteoarthritis

    PubMed Central

    Rönn, Karolin; Reischl, Nikolaus; Gautier, Emanuel; Jacobi, Matthias

    2011-01-01

    Osteoathritis (OA) of the knee is common, and the chances of suffering from OA increase with age. Its treatment should be initially nonoperative—and requires both pharmacological and nonpharmacological treatment modalities. If conservative therapy fails, surgery should be considered. Surgical treatments for knee OA include arthroscopy, cartilage repair, osteotomy, and knee arthroplasty. Determining which of these procedures is most appropriate depends on several factors, including the location, stage of OA, comorbidities on the one side and patients suffering on the other side. Arthroscopic lavage and débridement is often carried out, but does not alter disease progression. If OA is limited to one compartment, unicompartmental knee arthroplasty or unloading osteotomy can be considered. They are recommended in young and active patients in regard to the risks and limited durability of total knee replacement. Total arthroplasty of the knee is a common and safe method in the elderly patients with advanced knee OA. This paper summarizes current surgical treatment strategies for knee OA, with a focus on the latest developments, indications and level of evidence. PMID:22046517

  1. Basic biomechanic principles of knee instability.

    PubMed

    Zlotnicki, Jason P; Naendrup, Jan-Hendrik; Ferrer, Gerald A; Debski, Richard E

    2016-06-01

    Motion at the knee joint is a complex mechanical phenomenon. Stability is provided by a combination of static and dynamic structures that work in concert to prevent excessive movement or instability that is inherent in various knee injuries. The anterior cruciate ligament (ACL) is a main stabilizer of the knee, providing both translational and rotatory constraint. Despite the high volume of research directed at native ACL function, pathogenesis and surgical reconstruction of this structure, a gold standard for objective quantification of injury and subsequent repair, has not been demonstrated. Furthermore, recent studies have suggested that novel anatomic structures may play a significant role in knee stability. The use of biomechanical principles and testing techniques provides essential objective/quantitative information on the function of bone, ligaments, joint capsule, and other contributing soft tissues in response to various loading conditions. This review discusses the principles of biomechanics in relation to knee stability, with a focus on the objective quantification of knee stability, the individual contributions of specific knee structures to stability, and the most recent technological advances in the biomechanical evaluation of the knee joint. PMID:27007474

  2. Conservative biomechanical strategies for knee osteoarthritis.

    PubMed

    Reeves, Neil D; Bowling, Frank L

    2011-02-01

    Knee osteoarthritis (OA) is one of the most prevalent forms of this disease, with the medial compartment most commonly affected. The direction of external forces and limb orientation during walking results in an adduction moment that acts around the knee, and this parameter is regarded as a surrogate measure of medial knee compression. The knee adduction moment is intimately linked with the development and progression of knee OA and is, therefore, a target for conservative biomechanical intervention strategies, which are the focus of this Review. We examine the evidence for walking barefoot and the use of lateral wedge insoles and thin-soled, flexible shoes to reduce the knee adduction moment in patients with OA. We review strategies that directly affect the gait, such as walking with the foot externally rotated ('toe-out gait'), using a cane, lateral trunk sway and gait retraining. Valgus knee braces and muscle strengthening are also discussed for their effect upon reducing the knee adduction moment. PMID:21289615

  3. Vaccine epidemiology: A review

    PubMed Central

    Lahariya, Chandrakant

    2016-01-01

    This review article outlines the key concepts in vaccine epidemiology, such as basic reproductive numbers, force of infection, vaccine efficacy and effectiveness, vaccine failure, herd immunity, herd effect, epidemiological shift, disease modeling, and describes the application of this knowledge both at program levels and in the practice by family physicians, epidemiologists, and pediatricians. A case has been made for increased knowledge and understanding of vaccine epidemiology among key stakeholders including policy makers, immunization program managers, public health experts, pediatricians, family physicians, and other experts/individuals involved in immunization service delivery. It has been argued that knowledge of vaccine epidemiology which is likely to benefit the society through contributions to the informed decision-making and improving vaccination coverage in the low and middle income countries (LMICs). The article ends with suggestions for the provision of systematic training and learning platforms in vaccine epidemiology to save millions of preventable deaths and improve health outcomes through life-course. PMID:27453836

  4. An Analysis of the Full-Floating Journal Bearing

    NASA Technical Reports Server (NTRS)

    Shaw, M C; Nussdorfer, T J , Jr

    1947-01-01

    An analysis of the operating characteristics of a full-floating journal bearing, a bearing in which a floating sleeve is located between the journal and bearing surfaces, is presented together with charts from which the performance of such bearings may be predicted. Examples are presented to illustrate the use of these charts and a limited number of experiments conducted upon a glass full-floating bearing are reported to verify some results of the analysis.

  5. [Epidemiology and heterogeny].

    PubMed

    Breilh, J; Granda, E

    1989-01-01

    The innovation of epidemiology plays a crucial role in the development of the health sciences. The authors emphasize the importance of epistemological analysis related to scientific and technical production. They focus on the theoretical and methodological contributions of the principal Latin American groups in the field of epidemiology, stating their main accomplishments, issues and potentials. When reviewing those conceptual and practical innovations, the authors analyse the effects of broader historical conditions on scientific work. To them, Latin American contemporary innovative epidemiological research and production have developed clearly differentiated principles, methods and technical projections which have led to a movement of critical or 'social' epidemiology. The functionalist approach of conventional epidemiology, characterized by an empiricist viewpoint, is being overcome by a more rigorous and analytical approach. This new epidemiological approach, in which the authors as members of CEAS (Health Research and Advisory Center) are working, has selectively incorporated some of the technical instruments of conventional epidemiology, subordinating them to a different theoretical and logical paradigm. The new framework of this group explains the need to consider the people's objective situation and necessities, when constructing scientific interpretations and planning technical action. In order to accomplish this goal, epidemiological reasoning has to reflect the unity of external epidemiological facts and associations, the so-called phenomenological aspect of health, with the underlying determinants and conditioning processes or internal relations, which are the essence of the health-disease production and distribution process. Epidemiological analysis is considered not only as a problem of empirical observation but as a process of theoretical construction, in which there is a dynamic fusion of deductive and inductive reasoning.(ABSTRACT TRUNCATED AT 250

  6. Development of the Occupational Activities Knee Scale.

    PubMed

    Styron, Joseph F; Singer, Mendel E; Barsoum, Wael K

    2010-06-01

    A primary concern of many knee surgery patients is their ability to return to work following surgery, but it is often difficult to predict the practicality of returning due to a job's unclear knee demands. A cross-sectional study of employed patients and general population participants was conducted. Study participants were asked if their job required nine separate tasks and if their job had low, moderate, or high physical demands. The relative risk of each task placing high demands on the knee was calculated, and those risk ratios were summated to calculate a scaled score. The scaled score accurately distinguishes the levels of job demands with each reported level of job demands having a significantly higher mean scaled score than the level below it (p < 0.0001). The Occupational Activities Knee Scale offers occupational and health care providers greater precision in comparing the physical requirements of jobs for knee surgery patients. PMID:21141686

  7. MR imaging of the postoperative knee.

    PubMed

    Gnannt, Ralph; Chhabra, Avneesh; Theodoropoulos, John S; Hodler, Juerg; Andreisek, Gustav

    2011-11-01

    Advances in orthopedic and arthroscopic surgical procedures of the knee such as, knee replacement, ligamentous reconstruction as well as articular cartilage and meniscus repair techniques have resulted in a significant increase in the number of patients undergoing knee arthroscopy or open surgery. As a consequence postoperative MR imaging examinations increase. Comprehensive knowledge of the normal postoperative MR imaging appearances and abnormal findings in the knee associated with failure or complications of common orthopedic and arthroscopic surgical procedures currently undertaken is crucial. This article reviews the various normal and pathological postoperative MR imaging findings following anterior and posterior cruciate ligament, medial collateral ligament and posterolateral corner reconstruction, meniscus and articular cartilage surgery as well as total knee arthroplasty with emphasis on those surgical procedures which general radiologists will likely be faced in their daily clinical routine. PMID:22002752

  8. Traditional epidemiology, modern epidemiology, and public health.

    PubMed Central

    Pearce, N

    1996-01-01

    There have been significant developments in epidemiologic methodology during the past century, including changes in basic concepts, methods of data analysis, and methods of exposure measurement. However, the rise of modern epidemiology has been a mixed blessing, and the new paradigm has major shortcomings, both in public health and in scientific terms. The changes in the paradigm have not been neutral but have rather helped change--and have reflected changes in--the way in which epidemiologists think about health and disease. The key issue has been the shift in the level of analysis from the population to the individual. Epidemiology has largely ceased to function as part of a multidisciplinary approach to understanding the causation of disease in populations and has become a set of generic methods for measuring associations of exposure and disease in individuals. This reductionist approach focuses on the individual, blames the victim, and produces interventions that can be harmful. We seem to be using more and more advanced technology to study more and more trivial issues, while the major causes of disease are ignored. Epidemiology must reintegrate itself into public health and must rediscover the population perspective. PMID:8629719

  9. Regional or general anesthesia for fast-track hip and knee replacement - what is the evidence?

    PubMed

    Kehlet, Henrik; Aasvang, Eske Kvanner

    2015-01-01

    Regional anesthesia for knee and hip arthroplasty may have favorable outcome effects compared with general anesthesia by effectively blocking afferent input, providing initial postoperative analgesia, reducing endocrine metabolic responses, and providing sympathetic blockade with reduced bleeding and less risk of thromboembolic complications but with undesirable effects on lower limb motor and urinary bladder function. Old randomized studies supported the use of regional anesthesia with fewer postoperative pulmonary and thromboembolic complications, and this has been supported by recent large non-randomized epidemiological database cohort studies. In contrast, the data from newer randomized trials are conflicting, and recent studies using modern general anesthetic techniques may potentially support the use of general versus spinal anesthesia. In summary, the lack of properly designed large randomized controlled trials comparing modern general anesthesia and spinal anesthesia for knee and hip arthroplasty prevents final recommendations and calls for prospective detailed studies in this clinically important field. PMID:26918127

  10. Radionuclide therapy for arthritic knees

    SciTech Connect

    Doepel, L.K.

    1985-02-08

    A new radionuclide therapeutic approach for rheumatoid arthritis of the knee is described. This therapy combines a short-lived radionuclide with a carrier whose physical and chemical characteristics aid retention of the radioactive particles within the joint. Joining a radionuclide to a particulate carrier had not been explored previously as a potential method for inhibiting radiation leakage. The treatment couples the rare earth element dysprosium 165 to ferric hydroxide in macroaggregate form (size range: 3 to 10 ..mu..m). After the relatively inert iron complex penetrates the synovium, it causes cell death. Macrophages and phagocytes clear away the cellular debris, essentially eliminating the synovium.

  11. Automatic locking knee brace joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce (Inventor)

    1995-01-01

    This invention is an apparatus for controlling the pivotal movement of a knee brace comprising a tang-and-clevis joint that has been uniquely modified. Both the tang and the clevis have a set of teeth that, when engaged, can lock the tang and the clevis together. In addition, the tang is biased away from the clevis. Consequently, when there is no axial force (i.e., body weight) on the tang, the tang is free to pivot within the clevis. However, when an axial force is exerted on the tang, the tang is pushed into the clevis, both sets of teeth engage, and the tang and the clevis lock together.

  12. Rothia prosthetic knee joint infection.

    PubMed

    Trivedi, Manish N; Malhotra, Prashant

    2015-08-01

    Rothia species - Gram-positive pleomorphic bacteria that are part of the normal oral and respiratory flora - are commonly associated with dental cavities and periodontal disease although systemic infections have been described. We describe a 53-year-old female with rheumatoid arthritis complicated by prosthetic knee joint infection due to Rothia species, which was successfully treated by surgical removal of prosthesis and prolonged antimicrobial therapy. The issue of antibiotic prophylaxis before dental procedures among patients with prosthetic joint replacements is discussed. PMID:23357608

  13. Closure in Knee Replacement Surgery

    PubMed Central

    Kharat, Kiran

    2012-01-01

    Total Knee replacement (TKR) is one of the commonest arthroplasty surgeries performed. Various techniques of closures in TKR are described. This technical note describes an useful technique of achieving water tight closure in TKR. An optimal tension watertight closure also reduces the chances of dead space hematomas and infection. The author has described his technique where the soft tissues are never unduly compromised. In his experience the patient can be mobilized freely in bed and even allowed to sleep prone after first wound check.

  14. MRI EVALUATION OF KNEE CARTILAGE

    PubMed Central

    Rodrigues, Marcelo Bordalo; Camanho, Gilberto Luís

    2015-01-01

    Through the ability of magnetic resonance imaging (MRI) to characterize soft tissue noninvasively, it has become an excellent method for evaluating cartilage. The development of new and faster methods allowed increased resolution and contrast in evaluating chondral structure, with greater diagnostic accuracy. In addition, physiological techniques for cartilage assessment that can detect early changes before the appearance of cracks and erosion have been developed. In this updating article, the various techniques for chondral assessment using knee MRI will be discussed and demonstrated. PMID:27022562

  15. The Painful Total Knee Arthroplasty.

    PubMed

    McDowell, Mitchell; Park, Andrew; Gerlinger, Tad L

    2016-04-01

    There are many causes of residual pain after total knee arthroplasty (TKA). Evaluation and management begins with a comprehensive history and physical examination, followed by radiographic evaluation of the replaced and adjacent joints, as well as previous films of the replaced joint. Further workup includes laboratory analysis, along with a synovial fluid aspirate to evaluate the white blood cell count with differential as well as culture. Advanced imaging modalities may be beneficial when the diagnosis remains unclear. Revision surgery is not advisable without a clear diagnosis, as it may be associated with poor results. PMID:26772940

  16. Evaluation and floating enhancement of levodopa sustained release floating minitablets coated with insoluble acrylic polymer.

    PubMed

    Goole, J; Amighi, K; Vanderbist, F

    2008-08-01

    This article describes the in vitro evaluation and the enhancement of the floating properties of coated sustained release (SR) minitablets (MTs). The evaluated system consisted of a 3-mm drug-containing gas-generating core prepared by melt granulation and subsequent compression, which was then coated with a flexible polymeric membrane. Eudragit RL30D and acetyl triethylcitrate were used as a film former and a plasticizer, respectively. The coating level was fixed at 20% (wt/wt). The optimally coated floating MTs floated within 10 min and remained buoyant for more than 13 h, regardless of the pH of the test medium. By evaluating the dissolution profiles of levodopa at different pH, it was found that the release of levodopa was sustained for more than 12 h regardless of the pH, even if the coating did not cancel the effect of the pH-dependent solubility of the active drug. Finally, the robustness of the coated floating MTs was assessed by testing the drug release variability in function of the stirring conditions during dissolution tests. PMID:18618310

  17. Development and in vivo floating behavior of verapamil HCl intragastric floating tablets.

    PubMed

    Patel, Anand; Modasiya, Moin; Shah, Dushyant; Patel, Vishnu

    2009-01-01

    A novel gastro retentive controlled release drug delivery system of verapamil HCl was formulated in an effort to increase the gastric retention time of the dosage form and to control drug release. Hydroxypropylmethylcellulose (HPMC), carbopol, and xanthan gum were incorporated for gel-forming properties. Buoyancy was achieved by adding an effervescent mixture of sodium bicarbonate and anhydrous citric acid. In vitro drug release studies were performed, and drug release kinetics was evaluated using the linear regression method. The optimized intragastric floating tablet composed of 3:2 of HPMC K4M to xanthan gum exhibited 95.39% drug release in 24 h in vitro, while the buoyancy lag time was 36.2 s, and the intragastric floating tablet remained buoyant for >24 h. Zero-order and non-Fickian release transport was confirmed as the drug release mechanism from the optimized formulation (F7). X-ray studies showed that total buoyancy time was able to delay the gastric emptying of verapamil HCl intragastric floating tablet in mongrel dogs for more than 4 h. Optimized intragastric floating tablet showed no significant change in physical appearance, drug content, total buoyancy time, or in vitro dissolution pattern after storage at 40 degrees C/75% relative humidity for 3 months. PMID:19296224

  18. Differences in Anatomy and Kinematics in Asian and Caucasian TKA Patients: Influence on Implant Positioning and Subsequent Loading Conditions in Mobile Bearing Knees

    PubMed Central

    Kim, Tae Kyun; Miehlke, Rolf K.; Grupp, Thomas M.

    2014-01-01

    The objective of our study was to determine the mechanical stress conditions under tibiofemoral loading with an overlay of knee kinematics in deep flexion on two different mobile bearing designs in comparison to in vivo failure modes. This study investigates the seldom but severe complication of fatigue failure of polyethylene components at mobile bearing total knee arthroplasty designs. Assuming a combination of a floor-based lifestyle and tibial malrotation as a possible reason for a higher failure rate in Asian countries we developed a simplified finite element model considering a tibiofemoral roll-back angle of 22° and the range of rotational motion of a clinically established floating platform design (e.motion FP) at a knee flexion angle of 120° in order to compare our results to failure modes found in retrieved implants. Compared to the failure mode observed in the clinical retrievals the locations of the occurring stress maxima as well as the tensile stress distribution show analogies. From our observations, we conclude that the newly introduced finite element model with an overlay of deep knee flexion (lateral roll-back) and considerable internally rotated tibia implant positioning is an appropriate analysis for knee design optimizations and a suitable method to predict clinical failure modes. PMID:25538943

  19. Differences in anatomy and kinematics in Asian and Caucasian TKA patients: influence on implant positioning and subsequent loading conditions in mobile bearing knees.

    PubMed

    Maas, Allan; Kim, Tae Kyun; Miehlke, Rolf K; Hagen, Thomas; Grupp, Thomas M

    2014-01-01

    The objective of our study was to determine the mechanical stress conditions under tibiofemoral loading with an overlay of knee kinematics in deep flexion on two different mobile bearing designs in comparison to in vivo failure modes. This study investigates the seldom but severe complication of fatigue failure of polyethylene components at mobile bearing total knee arthroplasty designs. Assuming a combination of a floor-based lifestyle and tibial malrotation as a possible reason for a higher failure rate in Asian countries we developed a simplified finite element model considering a tibiofemoral roll-back angle of 22° and the range of rotational motion of a clinically established floating platform design (e.motion FP) at a knee flexion angle of 120° in order to compare our results to failure modes found in retrieved implants. Compared to the failure mode observed in the clinical retrievals the locations of the occurring stress maxima as well as the tensile stress distribution show analogies. From our observations, we conclude that the newly introduced finite element model with an overlay of deep knee flexion (lateral roll-back) and considerable internally rotated tibia implant positioning is an appropriate analysis for knee design optimizations and a suitable method to predict clinical failure modes. PMID:25538943

  20. Real-Time Tracking of Knee Adduction Moment in Patients with Knee Osteoarthritis

    PubMed Central

    Kang, Sang Hoon; Lee, Song Joo; Zhang, Li-Qun

    2014-01-01

    Background The external knee adduction moment (EKAM) is closely associated with the presence, progression, and severity of knee osteoarthritis (OA). However, there is a lack of convenient and practical method to estimate and track in real-time the EKAM of patients with knee OA for clinical evaluation and gait training, especially outside of gait laboratories. New Method A real-time EKAM estimation method was developed and applied to track and investigate the EKAM and other knee moments during stepping on an elliptical trainer in both healthy subjects and a patient with knee OA. Results Substantial changes were observed in the EKAM and other knee moments during stepping in the patient with knee OA. Comparison with Existing Method(s) This is the first study to develop and test feasibility of real-time tracking method of the EKAM on patients with knee OA using 3-D inverse dynamics. Conclusions The study provides us an accurate and practical method to evaluate in real-time the critical EKAM associated with knee OA, which is expected to help us to diagnose and evaluate patients with knee OA and provide the patients with real-time EKAM feedback rehabilitation training. PMID:24361759

  1. Floating production unit to work off Brazil

    SciTech Connect

    Not Available

    1992-10-19

    This paper reports that Petroleo Brasileiro SA expects by early November to deploy its Petrobras XXIV floating production unit (FPU) in about 900 ft of water in Albacora field off Brazil. The FPU was scheduled to depart Galveston, Tex., this month, following completion of modifications and upgrades under a turnkey contract with Chiles Offshore International Inc. Chiles began modifying Petrobras XXIV about 1 year ago as part of a deal closed in October 1991 in which Chiles Offshore Corp. sold the vessel, then known as Intrepid, to Brasoil, the international subsidiary of Petrobras.

  2. Floating hydrometer with energy dissipating baffle

    SciTech Connect

    Kownurko, W.A.

    1987-11-24

    This patent describes a floating hydrometer employable for purposes of obtaining measurements of the presence of suspended solids in a fluid substance contained in a receptacle comprising: a. a probe portion operative as an instrument-bearing housing; b. an elongated tubular element having a hollow interior and at least one open end so as to enable the flow into the hollow interior of the elongated tubular element through the open end; and c. energy dissipating baffle means having a first mode of action and a second mode of action and including a member having a hollow interior.

  3. An integrated circuit floating point accumulator

    NASA Technical Reports Server (NTRS)

    Goldsmith, T. C.

    1977-01-01

    Goddard Space Flight Center has developed a large scale integrated circuit (type 623) which can perform pulse counting, storage, floating point compression, and serial transmission, using a single monolithic device. Counts of 27 or 19 bits can be converted to transmitted values of 12 or 8 bits respectively. Use of the 623 has resulted in substantial savaings in weight, volume, and dollar resources on at least 11 scientific instruments to be flown on 4 NASA spacecraft. The design, construction, and application of the 623 are described.

  4. Floating air riding seal for a turbine

    DOEpatents

    Ebert, Todd A

    2016-08-16

    A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber formed in the stator, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, where the axial moveable annular piston includes an inlet scoop on a side opposite to the annular cavity that scoops up the swirling cooling air and directs the cooling air to the annular cavity to form an air cushion with the seal surface of the rotor.

  5. [Epidemiological research in Brazil].

    PubMed

    Guimarães, R; Lourenço-De-Oliveira, R; Cosac, S

    2001-08-01

    The current epidemiological research in Brazil is described. Secondary data sources were consulted, such as the year 2000 database of the Brazilian Directory of Research Groups and the National Board of Scientific and Technological Development (CNPq). The criterion to identify a group as a research one relies on the existence of at least one research line in the field of epidemiology, as defined by the group leader. After identifying the defined universe of epidemiological research, which included 176 groups and 320 different research lines, the following issues were presented and discussed: the relationships between research financing and health research, focusing on CAPES (Coordination Center for the Advance of University Professionals) graduation programs, public health research and epidemiological research, geographic and institutional distribution and outreach of the current epidemiological research, the researchers and students directly participating in epidemiological research, research topics and patterns of disseminating research findings; the journals where papers in its fullness were published; the financial support of the epidemiological research focusing on the 23 officially recognized graduate programs in public health field. PMID:11600921

  6. Epidemiology: Then and Now.

    PubMed

    Kuller, Lewis H

    2016-03-01

    Twenty-five years ago, on the 75th anniversary of the Johns Hopkins Bloomberg School of Public Health, I noted that epidemiologic research was moving away from the traditional approaches used to investigate "epidemics" and their close relationship with preventive medicine. Twenty-five years later, the role of epidemiology as an important contribution to human population research, preventive medicine, and public health is under substantial pressure because of the emphasis on "big data," phenomenology, and personalized medical therapies. Epidemiology is the study of epidemics. The primary role of epidemiology is to identify the epidemics and parameters of interest of host, agent, and environment and to generate and test hypotheses in search of causal pathways. Almost all diseases have a specific distribution in relation to time, place, and person and specific "causes" with high effect sizes. Epidemiology then uses such information to develop interventions and test (through clinical trials and natural experiments) their efficacy and effectiveness. Epidemiology is dependent on new technologies to evaluate improved measurements of host (genomics), epigenetics, identification of agents (metabolomics, proteomics), new technology to evaluate both physical and social environment, and modern methods of data collection. Epidemiology does poorly in studying anything other than epidemics and collections of numerators and denominators without specific hypotheses even with improved statistical methodologies. PMID:26493266

  7. When it hurts, a positive attitude may help: The association of positive affect with daily walking in knee OA: the MOST Study

    PubMed Central

    White, Daniel K; Keysor, Julie J; Neogi, Tuhina; Felson, David T; LaValley, Michael; Gross, K Doug; Niu, Jingbo; Nevitt, Michael; Lewis, Cora E; Torner, Jim; Fredman, Lisa

    2012-01-01

    OBJECTIVE While depressive symptoms and knee pain are independently known to impede daily walking in older adults, it is unknown whether positive affect promotes daily walking. This study investigated this association among adults with knee osteoarthritis (OA) and examined whether knee pain modified this association. DESIGN Cross-sectional analysis of the Multicenter Osteoarthritis Study. We included 1018 participants (mean age 63.1 ± 7.8 years, 60% female) who had radiographic knee OA and had worn a StepWatch monitor to record steps/day. High- and low- positive affect, and depressive symptoms were based on the Center for Epidemiologic Studies-Depression Scale. Knee pain was categorized as present in respondents who reported pain on most days at both a clinic visit and a telephone screen. RESULTS Compared to respondents with low positive affect (27% of respondents), those with high positive affect (63%) walked similar steps/day while those with depressive symptoms (10%) walked less (adjusted beta coefficients = −32.6 [−458.9, 393.8] and −579.1 [−1274.9, 116.7], respectively). There was a statistically significant interaction of positive affect by knee pain (p= 0.0045). Among respondents with knee pain (39%), those with high positive affect walked significantly more steps/day (711.0 [55.1, 1366.9]) than those with low positive affect. CONCLUSION High positive affect was associated with more daily walking among adults with painful knee OA. Positive affect may be an important psychological factor to consider to promote physical activity among people with painful knee OA. PMID:22504854

  8. Epidemiology of Injuries and Prevention Strategies in Competitive Swimmers

    PubMed Central

    Wanivenhaus, Florian; Fox, Alice J. S.; Chaudhury, Salma; Rodeo, Scott A.

    2012-01-01

    Context: Competitive swimmers are predisposed to musculoskeletal injuries of the upper limb, knee, and spine. This review discusses the epidemiology of these injuries, in addition to prevention strategies that may assist the physician in formulating rehabilitation programs for the swimmer following an injury. Evidence Acquisition: A literature search was performed by a review of Google Scholar, OVID, and PubMed articles published from 1972 to 2011. Results: This study highlights the epidemiology of injuries common to competitive swimmers and provides prevention strategies for the sports health professional. Conclusions: An understanding of swimming biomechanics and typical injuries in swimming aids in early recognition of injury, initiation of treatment, and design of optimal prevention and rehabilitation strategies. PMID:23016094

  9. Evolution and social epidemiology.

    PubMed

    Nishi, Akihiro

    2015-11-01

    Evolutionary biology, which aims to explain the dynamic process of shaping the diversity of life, has not yet significantly affected thinking in social epidemiology. Current challenges in social epidemiology include understanding how social exposures can affect our biology, explaining the dynamics of society and health, and designing better interventions that are mindful of the impact of exposures during critical periods. I review how evolutionary concepts and tools, such as fitness gradient in cultural evolution, evolutionary game theory, and contemporary evolution in cancer, can provide helpful insights regarding social epidemiology. PMID:26319950

  10. 40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... float glass manufacturing subcategory. 426.50 Section 426.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Float Glass Manufacturing Subcategory § 426.50 Applicability; description of the float...

  11. 40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... float glass manufacturing subcategory. 426.50 Section 426.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Float Glass Manufacturing Subcategory § 426.50 Applicability; description of the float...

  12. The Cruciate Ligaments in Total Knee Arthroplasty.

    PubMed

    Parcells, Bertrand W; Tria, Alfred J

    2016-01-01

    The early knee replacements were hinge designs that ignored the ligaments of the knee and resurfaced the joint, allowing freedom of motion in a single plane. Advances in implant fixation paved the way for modern designs, including the posterior-stabilized (PS) total knee arthroplasty (TKA) that sacrifices both cruciate ligaments while substituting for the posterior cruciate ligament (PCL), and the cruciate-retaining (CR) TKA designs that sacrifice the anterior cruciate ligament but retain the PCL. The early bicruciate retaining (BCR) TKA designs suffered from loosening and early failures. Townley and Cartier designed BCR knees that had better clinical results but the surgical techniques were challenging.Kinematic studies suggest that normal motion relies on preservation of both cruciate ligaments. Unicompartmental knee arthroplasty retains all knee ligaments and closely matches normal motion, while PS and CR TKA deviate further from normal. The 15% to 20% dissatisfaction rate with current TKA has renewed interest in the BCR design. Replication of normal knee kinematics and proprioception may address some of the dissatisfaction. PMID:27327919

  13. Surgical approaches for total knee arthroplasty.

    PubMed

    Vaishya, Raju; Vijay, Vipul; Demesugh, Daniel Mue; Agarwal, Amit Kumar

    2016-01-01

    There are various surgical approaches to the knee joint and its surrounding structures and such approaches are generally designed to allow the best access to an area of pathology whilst safeguarding important surrounding structures. Controversy currently surrounds the optimal surgical approach for total knee arthroplasty (TKA). The medial parapatellar arthrotomy, or anteromedial approach, has been the most used and has been regarded as the standard approach for exposure of the knee joint. It provides extensive exposure and is useful for open anterior cruciate ligament reconstruction, total knee replacement, and fixation of intra-articular fractures. Because this approach has been implicated in compromise of the patellar circulation, some authors have advocated the subvastus, midvastus, and trivector approaches for exposure of the knee joint. While these approaches expose the knee from the medial side, the anterolateral approach exposes the knee joint from the lateral side. With careful planning and arthrotomy selection, the anterior aspect of the joint can be adequately exposed for TKA in different clinical scenarios. PMID:27182142

  14. Drilling and production from a floating spar

    SciTech Connect

    Brooks, I.H.; Carroll, J.P.

    1994-12-31

    A deepwater drilling and production platform has been designed based on a floating spar. The spar is a catenary-moored cylindrical vessel having a deep draft which minimizes heave motions. The concept is an economic competitor with other deep water designs such as compliant towers and tension leg platforms. The spar`s oil storage capacity makes it particularly applicable for remote areas where pipeline infrastructure is unavailable and production is primarily from oil reservoirs. Without the need for a swivel, offloading of oil can be accomplished either directly from the spar, by use of a floating hose and support vessel, or by transfer to an offloading buoy. The concept is compatible with early production or phased development scenarios, permits surface completions of producing and injection wells, and allows for direct well intervention. The ability to reposition the spar by manipulations of the mooring lines favors a system of individual wellheads on the seafloor. Wells can be drilled, completed, and produced without pulling the drilling riser. When production from the field reaches its economic limit, the entire system can be towed to a new location and reused.

  15. Floating treatment wetlands for domestic wastewater treatment.

    PubMed

    Faulwetter, J L; Burr, M D; Cunningham, A B; Stewart, F M; Camper, A K; Stein, O R

    2011-01-01

    Floating islands are a form of treatment wetland characterized by a mat of synthetic matrix at the water surface into which macrophytes can be planted and through which water passes. We evaluated two matrix materials for treating domestic wastewater, recycled plastic and recycled carpet fibers, for chemical oxygen demand (COD) and nitrogen removal. These materials were compared to pea gravel or open water (control). Experiments were conducted in laboratory scale columns fed with synthetic wastewater containing COD, organic and inorganic nitrogen, and mineral salts. Columns were unplanted, naturally inoculated, and operated in batch mode with continuous recirculation and aeration. COD was efficiently removed in all systems examined (>90% removal). Ammonia was efficiently removed by nitrification. Removal of total dissolved N was ∼50% by day 28, by which time most remaining nitrogen was present as NO(3)-N. Complete removal of NO(3)-N by denitrification was accomplished by dosing columns with molasses. Microbial communities of interest were visualized with denaturing gradient gel electrophoresis (DGGE) by targeting specific functional genes. Shifts in the denitrifying community were observed post-molasses addition, when nitrate levels decreased. The conditioning time for reliable nitrification was determined to be approximately three months. These results suggest that floating treatment wetlands are a viable alternative for domestic wastewater treatment. PMID:22105133

  16. Evaporation mitigation using floating modular devices

    NASA Astrophysics Data System (ADS)

    Hassan, M. Mahmudul; Peirson, William Leslie; Neyland, Bryce M.; Fiddis, Nicholas McQuistan

    2015-11-01

    Reducing evaporation losses from open water storages is of paramount importance in the improvement of water security in arid countries, including Australia. Widespread adoption of evaporation mitigation techniques has been prevented by their high capital and maintenance or operating costs. The use of clean, floating recycled materials to mitigate evaporation technique has been investigated systematically at sites within both the coastal and semi-arid zones of Australia. Evaporation reduction systematically increases with the proportion of covered surface. Evaporation is reduced by 43% at coastal site and 37% at arid zone site at the maximum packing densities achievable for a single layer of floating devices. The study highlights the importance of both long-term investigations and the climatic influences in the robust quantification of evaporation mitigation. The effects of solar radiation, temperature, wind speed and relative humidity on the evaporation rate at both study sites have been determined in terms of both the classical Penman model and FAO Penman Monteith model with corresponding pan coefficients quantified. FAO Penman Monteith model better estimates evaporation from the open reference tank.

  17. Modal testing variability of spherical marine floats.

    SciTech Connect

    Robertson, A. N.; Hemez, F. M.; Salazar, I. F.; Duffey, T. A.

    2004-01-01

    This study investigates the variability in modal data obtained from testing a set of hollow, almost spherical marine floats. Four sources of variability are investigated: unit-to -unit variability, operator-to-operator variability, test repetition, and accelerometer placement. Because moving the accelerometers implies a test setup reconfiguration, it is expected that variability due to accelerometer placement should encompass variability due to test repetition. Similarly, the unit-to-unit variability should encompass both accelerometer placement variability and test-to -test variability. Impulse and frequency response functions are estimated from the measured excitation and response of the marine floats. A series of techniques are then used to assess the variation of the modal properties between each test, including: a measure of the spread of the frequency response functions in each test group; the variation of the temporal moments, spectral moments, and principal components; and the variability of resonant frequencies and modal damping ratios extracted from the data. The effects of mass and geometry on variability are also investigated. A strong correlation between the frequency and mass is found for the fundamental mode only. The main conclusion is that the majority of analysis techniques find the unit-to-unit variability to be the largest by a significant margin. The second largest is the variability caused by accelerometer placement. Next are the operator-to-operator variability and test-to -test variability.

  18. Water-Pressure Distribution on Seaplane Float

    NASA Technical Reports Server (NTRS)

    Thompson, F L

    1929-01-01

    The investigation presented in this report was conducted for the purpose of determining the distribution and magnitude of water pressures likely to be experienced on seaplane hulls in service. It consisted of the development and construction of apparatus for recording water pressures lasting one one-hundredth second or longer and of flight tests to determine the water pressures on a UO-1 seaplane float under various conditions of taxiing, taking off, and landing. The apparatus developed was found to operate with satisfactory accuracy and is suitable for flight tests on other seaplanes. The tests on the UO-1 showed that maximum pressures of about 6.5 pounds per square inch occur at the step for the full width of the float bottom. Proceeding forward from the step the maximum pressures decrease in magnitude uniformly toward the bow, and the region of highest pressures narrows toward the keel. Immediately abaft the step the maximum pressures are very small, but increase in magnitude toward the stern and there once reached a value of about 5 pounds per square inch. (author)

  19. Evaporation mitigation by floating modular devices

    NASA Astrophysics Data System (ADS)

    Hassan, M. M.; Peirson, W. L.

    2016-05-01

    Prolonged periods of drought and consequent evaporation from open water bodies in arid parts of Australia continue to be a threat to water availability for agricultural production. Over many parts of Australia, the annual average evaporation exceeds the annual precipitation by more than 5 times. Given its significance, it is surprising that no evaporation mitigation technique has gained widespread adoption to date. High capital and maintenance costs of manufactured products are a significant barrier to implementation. The use of directly recycled clean plastic containers as floating modular devices to mitigate evaporation has been investigated for the first time. A six-month trial at an arid zone site in Australia of this potential cost effective solution has been undertaken. The experiment was performed using clean conventional drinking water bottles as floating modules on the open water surface of 240-L tanks with three varying degrees of covering (nil, 34% and 68%). A systematic reduction in evaporation is demonstrated during the whole study period that is approximately linearly proportional to the covered surface. These results provide a potential foundation for robust evaporation mitigation with the prospect of implementing a cost-optimal design.

  20. Thermal Performance of the LDX Floating Coil

    NASA Astrophysics Data System (ADS)

    Zhukovsky, A.; Garnier, D. T.; Radovinsky, A. L.

    2006-04-01

    The Levitated Dipole Experiment (LDX) is an innovative facility to study plasma confinement in a dipole magnetic field, created by a superconducting solenoid (floating coil), which is magnetically levitated in the center of a 5 m diameter by 3 m tall vacuum chamber. The floating coil (F-coil) consists of a Nb3Sn magnet installed inside a strong vessel filled with high-pressure helium gas at room temperature. It is surrounded by a fiberglass-lead composite radiation shield and by a toroidal vacuum shell. The cryostat design provides the ability to operate the magnet for several hours of wanning while suspended in the middle of the vacuum chamber without electric and cryogenic connections to the coil. For this reason the magnet is charged/discharged inductively in a lower part of the vacuum chamber. The retractable cryogenic transfer lines serve to cool down the magnet to 4.5 K before it is lifted to the operating position. The F-coil can be re-cooled multiple times while maintaining its field and current. This paper describes the thermal performance of the F-coil.

  1. A laboratory study of floating lenticular anticyclones

    NASA Astrophysics Data System (ADS)

    Le Gal, Patrice; de La Rosa, Hector; Cros, Anne; Cruz-Gomez, Raúl; Le Bars, Michael

    2014-11-01

    Oceanic vortices play an important role in the redistribution of heat, salt and momentum in the oceans. Among these vortices, floating lenses or rings are often met in the meanders of warm currents. For instance the North Brazil Current rings are among the most intense and large anticyclonic vortices on Earth. In order to better describe these vortices, we propose here a laboratory study of these floating anticyclonic lenses. A blob of fresh water is slowly injected near the surface of a rotating layer of homogeneous salted water. Because of the opposite effects of rotation that tends to generate columnar structures and density stratification that spreads light water on the surface, the vortices take a finite size three dimensionnal typical shape. Visualization and PIV measurements of the shape, aspect ratios and vorticity profiles are compared to analytical predictions that use first a simple solid body rotation model and then a more realistic isolated Gaussian vorticity field inside the anticyclones. This work was carried out within the framework of a bilateral cooperation between CNRS (France) and CONACYT (Mexico).

  2. Knee arthrodesis – ultima ratio for the treatment of the infected knee

    PubMed Central

    Tiemann, Andreas H. H.

    2013-01-01

    The irretrievable destruction of the knee due to trauma, tumor or infection is the indication for knee arthrodesis. The main reason for knee arthrodesis in terms of infection ist the infected total knee arthroplasty. Central problem is the definition of the term “irretrievable”. It is based on the subjective opinion of the attending physician and depends on his expert knowledge of this specific entity. The preservation of a functioning extremity is the main goal. This article shows the typical indications and contraindications for knee arthrodesis following septic knee diseases. In addition it gives insight into the biomechanical and technical considerations to be kept in mind. Finally the postoperative care and outcome of different techniques are analysed. PMID:26504699

  3. 40 CFR 63.1043 - Standards-Separator floating roof.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Standards-Separator floating roof. 63...) National Emission Standards for Oil-Water Separators and Organic-Water Separators § 63.1043 Standards—Separator floating roof. (a) This section applies to owners and operators subject to this subpart...

  4. 14 CFR 136.11 - Helicopter floats for over water.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Helicopter floats for over water. 136.11... floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must... controls, and (2) The flotation system armed when the helicopter is over water and is flying at a...

  5. 14 CFR 136.11 - Helicopter floats for over water.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Helicopter floats for over water. 136.11... floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must... controls, and (2) The flotation system armed when the helicopter is over water and is flying at a...

  6. 14 CFR 136.11 - Helicopter floats for over water.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Helicopter floats for over water. 136.11... floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must... controls, and (2) The flotation system armed when the helicopter is over water and is flying at a...

  7. 14 CFR 136.11 - Helicopter floats for over water.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Helicopter floats for over water. 136.11... floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must... controls, and (2) The flotation system armed when the helicopter is over water and is flying at a...

  8. 14 CFR 136.11 - Helicopter floats for over water.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Helicopter floats for over water. 136.11... floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must... controls, and (2) The flotation system armed when the helicopter is over water and is flying at a...

  9. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Life floats. 144.01-1 Section 144.01-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each...

  10. 14 CFR 27.521 - Float landing conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ....473(b) or assumed to be equal to that determined for wheel landing gear): (a) Up-load conditions in... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Float landing conditions. 27.521 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Water Loads § 27.521 Float...

  11. 14 CFR 29.521 - Float landing conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... factor is determined under § 29.473(b) or assumed to be equal to that determined for wheel landing gear... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Float landing conditions. 29.521 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Water Loads § 29.521 Float...

  12. 14 CFR 27.521 - Float landing conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Float landing conditions. 27.521 Section 27.521 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Water Loads § 27.521 Float landing conditions. If certification for...

  13. 14 CFR 29.521 - Float landing conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Float landing conditions. 29.521 Section 29.521 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Water Loads § 29.521 Float landing conditions. If certification for...

  14. 14 CFR 29.521 - Float landing conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... factor is determined under § 29.473(b) or assumed to be equal to that determined for wheel landing gear... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Float landing conditions. 29.521 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Water Loads § 29.521 Float...

  15. 14 CFR 27.521 - Float landing conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ....473(b) or assumed to be equal to that determined for wheel landing gear): (a) Up-load conditions in... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Float landing conditions. 27.521 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Water Loads § 27.521 Float...

  16. 22. Float located adjacent to entry stair in filtration bed. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  17. 40 CFR 65.44 - External floating roof (EFR).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 16 2012-07-01 2012-07-01 false External floating roof (EFR). 65.44 Section 65.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Storage Vessels § 65.44 External floating roof (EFR). (a) EFR design requirements. The owner or operator...

  18. 14 CFR 23.535 - Auxiliary float loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary float loads. 23.535 Section 23.535 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.535 Auxiliary float loads. (a)...

  19. Epidemiology of Lice

    ERIC Educational Resources Information Center

    Juranek, Dennis D.

    1977-01-01

    Research into the epidemiology of lice indicates that infestation is uncommon in blacks, more common in females than males, significantly higher in low income groups, and transmission is by way of articles of clothing. (JD)

  20. Cancer Epidemiology Cohorts

    Cancer.gov

    Cohort studies are fundamental for epidemiological research by helping researchers better understand the etiology of cancer and provide insights into the key determinants of this disease and its outcomes.

  1. Epidemiology of varicocele

    PubMed Central

    Alsaikhan, Bader; Alrabeeah, Khalid; Delouya, Guila; Zini, Armand

    2016-01-01

    Varicocele is a common problem in reproductive medicine practice. A varicocele is identified in 15% of healthy men and up to 35% of men with primary infertility. The exact pathophysiology of varicoceles is not very well understood, especially regarding its effect on male infertility. We have conducted a systematic review of studies evaluating the epidemiology of varicocele in the general population and in men presenting with infertility. In this article, we have identified some of the factors that can influence the epidemiological aspects of varicoceles. We also recognize that varicocele epidemiology remains incompletely understood, and there is a need for well-designed, large-scale studies to fully define the epidemiological aspects of this condition. PMID:26763551

  2. Epidemiology of Toxoplasmosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infection with Toxoplasma gondii is highly prevalent throughout the world. This chapter discusses modes of transmission, the epidemiology of T. gondii infection worldwide and in Brazil, and methods of prevention and control....

  3. EPIDEMIOLOGY AND EXPOSURE ASSESSMENT

    EPA Science Inventory

    Research collaborations between the National Health and Environmental Effects Research Laboratory (NHEERL) and the National Exposure Research Laboratory (NERL) centered on the development and application of exposure analysis tools in environmental epidemiology include the El Paso...

  4. Epidemiology & Genomics Research Program

    Cancer.gov

    The Epidemiology and Genomics Research Program, in the National Cancer Institute's Division of Cancer Control and Population Sciences, funds research in human populations to understand the determinants of cancer occurrence and outcomes.

  5. Computer-assisted knee surgical navigation

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Zhou, D. G.; Xiong, Chun-Yang; Huang, W. P.; Fang, J.

    2002-05-01

    Total knee replacement requires high measurement accuracy and fixation precision in surgical operation. Misplacement larger than 5 degrees in the force line alignment will lead to re- operation or long term deficits. Based on conventional operation facilities, it was not easy to ensure the necessary precision during het surgery. With the help of CT images, 3D images of patient's knee can be reconstructed. With IR localizer, computer- assisted knee surgical navigation can be realized by tracking that is useful for accurate alignment in surgery and in visualized training program.

  6. SYNOVIAL GIANT CELL TUMOR OF THE KNEE

    PubMed Central

    Abdalla, Rene Jorge; Cohen, Moisés; Nóbrega, Jezimar; Forgas, Andrea

    2015-01-01

    Synovial giant cell tumor is a benign neoplasm, rarely reported in the form of malignant metastasis. Synovial giant cell tumor most frequently occurs on the hand, and, most uncommon, on the ankle and knee. In the present study, the authors describe a rare case of synovial giant cell tumor on the knee as well as the treatment approach. Arthroscopy has been shown, in this case, to be the optimal method for treating this kind of lesion, once it allowed a less aggressive approach, while providing good visualization of all compartments of knee joint and full tumor resection. PMID:27004193

  7. Distinguishing ankle and knee articular cartilage.

    PubMed

    Cole, Ada A; Margulis, Arkady; Kuettner, Klaus E

    2003-06-01

    Degenerative changes in the tall and femoral distal cartilages of more than 2,000 tissue donors were graded based on the appearance of articular cartilage and osteophytes. In the ankle and the knee the degenerative changes increased with age; however, the rate of degeneration in the ankle was slower than in the knee. The degenerative changes in the ankle were more severe in men than in women, were predominantly bilateral, and seemed to be correlated with weight. The slower rate of change in the ankle may be caused, in part, by the biochemical and biomechanical tissue properties that distinguish ankle cartilage from that of the knee. PMID:12911243

  8. Electrowetting in a water droplet with a movable floating substrate

    NASA Astrophysics Data System (ADS)

    Shahzad, Amir; Masud, A. R.; Song, Jang-Kun

    2016-05-01

    Electrowetting (EW) enables facile manipulation of a liquid droplet on a hydrophobic surface. In this study, manipulation of an electrolyte droplet having a small floating object on it was investigated on a solid hydrophobic substrate under the EW process. Herein, the floating object exhibited a vertical motion under an applied electric field owing to the spreading and contraction of the droplet on its connecting substrates. The field-induced height variation of the floating object was significantly influenced by the thicknesses of the dielectric and hydrophobic materials. A small mass was also placed on the top floating object and its effect on the spreading of the droplet was observed. In this system, the height of the top floating object is precisely controllable under the application of an electric voltage. The proposed system is expected to be highly useful in the design of nano- and micro-oscillatory systems for microengineering.

  9. Effect of a floating electrode on a plasma jet

    SciTech Connect

    Hu, J. T.; Wang, J. G.; Liu, X. Y.; Liu, D. W.; Lu, X. P.; Shi, J. J.; Ostrikov, K.

    2013-08-15

    Two kinds of floating electrode, floating dielectric barrier covered electrode (FDBCE) and floating pin electrode (FPE), which can enhance the performance of plasma jet are reported. The intense discharge between the floating electrode and power electrode decreased the voltage to trigger the plasma jet substantially. The transition of plasma bullet from ring shape to disk shape in the high helium concentration region happened when the floating electrode was totally inside the powered ring electrode. The enhanced electric field between propagating plasma bullet and ground electrode is the reason for this transition. The double plasma bullets happened when part of the FDBCE was outside the powered ring electrode, which is attributed to the structure and surface charge of FDBCE. As part of the FPE was outside the powered ring electrode, the return stroke resulted in a single intensified plasma channel between FPE and ground electrode.

  10. Electrowetting in a water droplet with a movable floating substrate.

    PubMed

    Shahzad, Amir; Masud, A R; Song, Jang-Kun

    2016-05-01

    Electrowetting (EW) enables facile manipulation of a liquid droplet on a hydrophobic surface. In this study, manipulation of an electrolyte droplet having a small floating object on it was investigated on a solid hydrophobic substrate under the EW process. Herein, the floating object exhibited a vertical motion under an applied electric field owing to the spreading and contraction of the droplet on its connecting substrates. The field-induced height variation of the floating object was significantly influenced by the thicknesses of the dielectric and hydrophobic materials. A small mass was also placed on the top floating object and its effect on the spreading of the droplet was observed. In this system, the height of the top floating object is precisely controllable under the application of an electric voltage. The proposed system is expected to be highly useful in the design of nano- and micro-oscillatory systems for microengineering. PMID:27300973

  11. Children's knowledge of hierarchical phrase structure: quantifier floating in Japanese.

    PubMed

    Suzuki, Takaaki; Yoshinaga, Naoko

    2013-06-01

    The interpretation of floating quantifiers in Japanese requires knowledge of hierarchical phrase structure. However, the input to children is insufficient or even misleading, as our analysis indicates. This presents an intriguing question on learnability: do children interpret floating quantifiers based on a structure-dependent rule which is not obvious in the input or do they employ a sentence comprehension strategy based on the available input? Two experiments examined four- to six-year-old Japanese-speaking children for their interpretations of floating quantifiers in SOV and OSV sentences. The results revealed that no child employed a comprehension strategy in terms of the linear ordering of constituents, and most five- and six-year-olds correctly interpreted floating quantifiers when word-order difficulty was reduced. These facts indicate that children's interpretation of floating quantifiers is structurally dependent on hierarchical phrase structure, suggesting that this knowledge is a part of children's grammar despite the insufficient input available to them. PMID:22850618

  12. Mid-term outcomes of primary constrained condylar knee arthroplasty for severe knee deformity.

    PubMed

    Feng, Xiao-Bo; Yang, Cao; Fu, De-Hao; Ye, Shu-Nan; Liu, Xian-Zhe; Chen, Zhe; Rai, Saroj; Yang, Shu-Hua

    2016-04-01

    This study aimed to examine the clinical and radiographic outcomes of primary total knee arthroplasy (TKA) with use of NexGen® Legacy® Constrained Condylar Knee (CCK) prosthesis for severe knee deformity. Clinical data of 46 patients (48 knees in total, aged 61 years on average) with severe knee deformity who underwent TKA with NexGen® Legacy® CCK prosthesis between December 2007 and February 2012 were retrospectively analyzed. There were 34 knees with severe valgus with incompetent medial collateral ligament, 11 knees with severe flexion contracture with inability to achieve knee balancing in flexion and extension by posterior soft tissue release, 2 knees with Charcot arthritis with severe varus and bone loss, and 1 with traumatic osteoarthritis with severe varus and ligamentous instability. The mean duration of follow-up was 71 months (range 40-90 months). The New Knee Society scoring (NKSS) system and the Hospital for Special Surgery (HSS) score were used to evaluate the functional and clinical outcomes. Visual Analogue Scale (VAS) was used for pain measurement and Knee Society criteria for evaluation of radiological images. The results showed that, in the total 48 knees, 1 case of loosening due to short-stem tibial component at 3 months post-operatively underwent revision. The 6-year prosthesis survival rate in this cohort was 97.9%. There was no component infection occurring within 6 years. Significant post-operative improvements were found in NKSS and HSS scores. Patient satisfaction was significantly increased. Pain score was decreased significantly. Total functional score was improved from 31.46±11.43 to 86.42±8.87, range of motion (ROM) from 42.42°±23.57° to 95.31°±23.45° and the flexion contracture from 5.31°±7.87° to 0.92°±1.80°. Preoperative radiographic study showed excessive valgus (≥7°) in 37 knees, and varus deformity in 3 knees. Post-operative femorotibial alignment was valgus 3.88°±1.76° in 48 knees. Antero/posterior (A

  13. Total knee arthroplasty in a rheumatoid arthritic knee with large geode: a case report.

    PubMed

    Shih, H N; Hsu, K Y; Tan, C F; Hsueh, S; Hsu, R W

    1997-09-01

    Geodes (subchondral cysts) are a well-known manifestation of rheumatoid arthritis. Solitary cysts or cysts larger than 2 cm are not generally found in the knee joint of patients with rheumatoid arthritis (RA). We report a case of RA involving both knees with a giant geode over the right proximal tibia. Surgical treatment was performed including synovectomy, cyst enucleation and packing of autogenous bone chips followed by primary total knee arthroplasty. The postsurgical result was excellent with the knee restored to good function and complete healing of the cystic lesion. PMID:9397618

  14. Examination of knee joint moments on the function of knee-ankle-foot orthoses during walking.

    PubMed

    Andrysek, Jan; Klejman, Susan; Kooy, John

    2013-08-01

    The goal of this study was to investigate clinically relevant biomechanical conditions relating to the setup and alignment of knee-ankle-foot orthoses and the influence of these conditions on knee extension moments and orthotic stance control during gait. Knee moments were collected using an instrumented gait laboratory and concurrently a load transducer embedded at the knee-ankle-foot orthosis knee joint of four individuals with poliomyelitis. We found that knee extension moments were not typically produced in late stance-phase of gait. Adding a dorsiflexion stop at the orthotic ankle significantly decreased the knee flexion moments in late stance-phase, while slightly flexing the knee in stance-phase had a variable effect. The findings suggest that where users of orthoses have problems initiating swing-phase flexion with stance control orthoses, an ankle dorsiflexion stop may be used to enhance function. Furthermore, the use of stance control knee joints that lock while under flexion may contribute to more inconsistent unlocking of the stance control orthosis during gait. PMID:23182738

  15. Discrete Element Modelling of Floating Debris

    NASA Astrophysics Data System (ADS)

    Mahaffey, Samantha; Liang, Qiuhua; Parkin, Geoff; Large, Andy; Rouainia, Mohamed

    2016-04-01

    Flash flooding is characterised by high velocity flows which impact vulnerable catchments with little warning time and as such, result in complex flow dynamics which are difficult to replicate through modelling. The impacts of flash flooding can be made yet more severe by the transport of both natural and anthropogenic debris, ranging from tree trunks to vehicles, wheelie bins and even storage containers, the effects of which have been clearly evident during recent UK flooding. This cargo of debris can have wide reaching effects and result in actual flood impacts which diverge from those predicted. A build-up of debris may lead to partial channel blockage and potential flow rerouting through urban centres. Build-up at bridges and river structures also leads to increased hydraulic loading which may result in damage and possible structural failure. Predicting the impacts of debris transport; however, is difficult as conventional hydrodynamic modelling schemes do not intrinsically include floating debris within their calculations. Subsequently a new tool has been developed using an emerging approach, which incorporates debris transport through the coupling of two existing modelling techniques. A 1D hydrodynamic modelling scheme has here been coupled with a 2D discrete element scheme to form a new modelling tool which predicts the motion and flow-interaction of floating debris. Hydraulic forces arising from flow around the object are applied to instigate its motion. Likewise, an equivalent opposing force is applied to fluid cells, enabling backwater effects to be simulated. Shock capturing capabilities make the tool applicable to predicting the complex flow dynamics associated with flash flooding. The modelling scheme has been applied to experimental case studies where cylindrical wooden dowels are transported by a dam-break wave. These case studies enable validation of the tool's shock capturing capabilities and the coupling technique applied between the two numerical

  16. Lockable Knee Brace Speeds Rehabilitation

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Marshall Space Flight Center develops key transportation and propulsion technologies for the Space Agency. The Center manages propulsion hardware and technologies of the space shuttle, develops the next generation of space transportation and propulsion systems, oversees science and hardware development for the International Space Station, manages projects and studies that will help pave the way back to the Moon, and handles a variety of associated scientific endeavors to benefit space exploration and improve life here on Earth. It is a large and diversified center, and home to a great wealth of design skill. Some of the same mechanical design skill that made its way into the plans for rocket engines and advanced propulsion at this Alabama-based NASA center also worked its way into the design of an orthotic knee joint that is changing the lives of people with weakened quadriceps.

  17. Rehabilitation of the arthrofibrotic knee.

    PubMed

    Millett, Peter J; Johnson, Burt; Carlson, Jeff; Krishnan, Sumant; Steadman, J Richard

    2003-11-01

    This paper describes the postoperative rehabilitation of the arthrofibrotic knee, with specific emphasis on modern rehabilitation techniques. The significance of prevention and early recognition is discussed. The importance of early motion and patellar mobility is emphasized and specific exercises to prevent and treat stiffness are described. Continuous passive motion, bracing, and exercise--on the stationary bicycle, on the treadmill, and in water--are adjuncts in the program. Strengthening is added when motion is re-established and there is no swelling or pain. Sport-specific activities are added if progress is satisfactory and motion is maintained. If pain, swelling, or stiffness develops, exercises should be discontinued. Modalities such as cryotherapy, ultrasound, electrical stimulation, rest, and manipulation can be used judiciously. Anti-inflammatory and analgesic medications should be used to prevent inflammation, to control pain, and to allow more aggressive rehabilitative exercises. PMID:14653482

  18. NAVIGATION IN TOTAL KNEE ARTHROPLASTY

    PubMed Central

    da Mota e Albuquerque, Roberto Freire

    2015-01-01

    Navigation was the most significant advance in instrumentation for total knee arthroplasty over the last decade. It provides surgeons with a precision tool for carrying out surgery, with the possibility of intraoperative simulation and objective control over various anatomical and surgical parameters and references. Since the first systems, which were basically used to control the alignment of bone cutting referenced to the mechanical axis of the lower limb, many other surgical steps have been incorporated, such as component rotation, ligament balancing and arranging the symmetry of flexion and extension spaces, among others. Its efficacy as a precision tool with an effective capacity for promoting better alignment of the lower-limb axis has been widely proven in the literature, but the real value of optimized alignment and the impact of navigation on clinical results and the longevity of arthroplasty have yet to be established. PMID:27026979

  19. Knee System Utilizing Personalized Solutions Instrumentation

    MedlinePlus

    ATTUNE® Knee System utilizing the TRUMATCH® Personalized Solutions Instrumentation Click Here to view the BroadcastMed, Inc. Privacy Policy and Legal Notice © 2016 BroadcastMed, Inc. All rights reserved.

  20. Progenitor model of cosmic ray knee

    NASA Astrophysics Data System (ADS)

    Bijay, Biplab; Bhadra, Arunava

    2016-01-01

    The primary energy spectrum of cosmic rays exhibits a knee at about 3 PeV where a change in the spectral index occurs. Despite many efforts, the origin of such a feature in the spectrum is not satisfactorily solved yet. Here it is proposed that the steepening of the spectrum beyond the knee may be a consequence of the mass distribution of the progenitor of the cosmic ray source. The proposed speculative model can account for all the major observed features of cosmic rays without invoking any fine tuning to match flux or spectra at any energy point. The prediction of the proposed model regarding the primary composition scenario beyond the knee is quite different from most of the prevailing models of the knee, and thereby can be discriminated from precise experimental measurement of the primary composition.

  1. Tai Chi: Rx for Arthritic Knees

    MedlinePlus

    ... Chi: Rx for Arthritic Knees As effective as physical therapy, study suggests, plus it might also improve depression ... 2016 (HealthDay News) -- Legions of arthritis sufferers try physical therapy and anti-inflammatory drugs to no avail. Now, ...

  2. Posterior cruciate ligament of the knee (image)

    MedlinePlus

    The posterior cruciate ligament (PCL) is a powerful ligament extending from the top-rear surface of the tibia to the bottom-front surface of the femur. The ligament prevents the knee joint from posterior instability.

  3. Knee bone tumors: findings on conventional radiology*

    PubMed Central

    Andrade Neto, Francisco; Teixeira, Manuel Joaquim Diógenes; Araújo, Leonardo Heráclio do Carmo; Ponte, Carlos Eduardo Barbosa

    2016-01-01

    The knee is a common site for bone tumors, whether clinically painful or not. Conventional radiology has been established as the first line of investigation in patients with knee pain and can reveal lesions that often generate questions not only for the generalist physician but also for the radiologist or general orthopedist. History, image examination, and histopathological analysis compose the essential tripod of the diagnosis of bone tumors, and conventional radiology is an essential diagnostic tool in patients with knee pain. This pictorial essay proposes to depict the main conventional radiography findings of the most common bone tumors around the knee, including benign and malignant tumors, as well as pseudo-tumors. PMID:27403019

  4. Computational Poromechanics of Human Knee Joint

    NASA Astrophysics Data System (ADS)

    Kazemi, Mojtaba; Li, LePing

    2012-02-01

    Extensive computer modeling has been performed in the recent decade to investigate the mechanical response of the healthy and repaired knee joints. Articular cartilages and menisci have been commonly modeled as single-phase elastic materials in the previous 3D simulations. A comprehensive study considering the interplay of the collagen fibers and fluid pressurization in the tissues in situ remains challenging. We have developed a 3D model of the human knee accounting for the mechanical function of collagen fibers and fluid flow in the cartilages and menisci. An anatomically accurate structure of the human knee was used for this purpose including bones, articular cartilages, menisci and ligaments. The fluid pressurization in the femoral cartilage and menisci under combined creep loading was investigated. Numerical results showed that fluid flow and pressure in the tissues played an important role in the mechanical response of the knee joint. The load transfer in the joint was clearly seen when the fluid pressure was considered.

  5. Cartilage Injuries in the Adult Knee

    PubMed Central

    Moyad, Thomas F.

    2011-01-01

    Cartilage injuries are frequently recognized as a source of significant morbidity and pain in patients with previous knee injuries. The majority of patients who undergo routine knee arthroscopy have evidence of a chondral defect. These injuries represent a continuum of pathology from small, asymptomatic lesions to large, disabling defects affecting a major portion of one or more compartments within the knee joint. In comparison to patients with osteoarthritis, individuals with isolated chondral surface damage are often younger, significantly more active, and usually less willing to accept limitations in activities that require higher impact. At the present time, a variety of surgical procedures exist, each with their unique indications. This heterogeneity of treatment options frequently leads to uncertainty regarding which techniques, if any, are most appropriate for patients. The purpose of this review is to describe the workup and discuss the management techniques for cartilage injuries within the adult knee. PMID:26069581

  6. Knee Pain and the Weekend Warriors

    MedlinePlus

    ... care. “OR-Live,” the vision of improving health. Hello, and welcome to Mercy Hospital. We’re in ... knee arthroscopy. Let me introduce first, Dr. Lavernia. Hello there. Dr. Lavernia Is the chief of the ...

  7. Partial Knee with Personalized Patient Care

    MedlinePlus Videos and Cool Tools

    Oxford® Partial Knee with Signature™ Personalized Patient Care You must have Javascript enabled in your web browser. View Program Transcript Click Here to view the OR-Live, Inc. Privacy Policy and ...

  8. Knee bone tumors: findings on conventional radiology.

    PubMed

    Andrade Neto, Francisco; Teixeira, Manuel Joaquim Diógenes; Araújo, Leonardo Heráclio do Carmo; Ponte, Carlos Eduardo Barbosa

    2016-01-01

    The knee is a common site for bone tumors, whether clinically painful or not. Conventional radiology has been established as the first line of investigation in patients with knee pain and can reveal lesions that often generate questions not only for the generalist physician but also for the radiologist or general orthopedist. History, image examination, and histopathological analysis compose the essential tripod of the diagnosis of bone tumors, and conventional radiology is an essential diagnostic tool in patients with knee pain. This pictorial essay proposes to depict the main conventional radiography findings of the most common bone tumors around the knee, including benign and malignant tumors, as well as pseudo-tumors. PMID:27403019

  9. Platelet Rich Plasma and Knee Surgery

    PubMed Central

    Sánchez, Mikel; Sánchez, Pello; Orive, Gorka; Anitua, Eduardo; Padilla, Sabino

    2014-01-01

    In orthopaedic surgery and sports medicine, the knee joint has traditionally been considered the workhorse. The reconstruction of every damaged element in this joint is crucial in achieving the surgeon's goal to restore the knee function and prevent degeneration towards osteoarthritis. In the last fifteen years, the field of regenerative medicine is witnessing a boost of autologous blood-derived platelet rich plasma products (PRPs) application to effectively mimic and accelerate the tissue healing process. The scientific rationale behind PRPs is the delivery of growth factors, cytokines, and adhesive proteins present in platelets and plasma, as well as other biologically active proteins conveyed by the plasma such as fibrinogen, prothrombin, and fibronectin; with this biological engineering approach, new perspectives in knee surgery were opened. This work describes the use of PRP to construct and repair every single anatomical structure involved in knee surgery, detailing the process conducted in ligament, meniscal, and chondral surgery. PMID:25302310

  10. MRI based knee cartilage assessment

    NASA Astrophysics Data System (ADS)

    Kroon, Dirk-Jan; Kowalski, Przemyslaw; Tekieli, Wojciech; Reeuwijk, Els; Saris, Daniel; Slump, Cornelis H.

    2012-03-01

    Osteoarthritis is one of the leading causes of pain and disability worldwide and a major health problem in developed countries due to the gradually aging population. Though the symptoms are easily recognized and described by a patient, it is difficult to assess the level of damage or loss of articular cartilage quantitatively. We present a novel method for fully automated knee cartilage thickness measurement and subsequent assessment of the knee joint. First, the point correspondence between a pre-segmented training bone model is obtained with use of Shape Context based non-rigid surface registration. Then, a single Active Shape Model (ASM) is used to segment both Femur and Tibia bone. The surfaces obtained are processed to extract the Bone-Cartilage Interface (BCI) points, where the proper segmentation of cartilage begins. For this purpose, the cartilage ASM is trained with cartilage edge positions expressed in 1D coordinates at the normals in the BCI points. The whole cartilage model is then constructed from the segmentations obtained in the previous step. An absolute thickness of the segmented cartilage is measured and compared to the mean of all training datasets, giving as a result the relative thickness value. The resulting cartilage structure is visualized and related to the segmented bone. In this way the condition of the cartilage is assessed over the surface. The quality of bone and cartilage segmentation is validated and the Dice's coefficients 0.92 and 0.86 for Femur and Tibia bones and 0.45 and 0.34 for respective cartilages are obtained. The clinical diagnostic relevance of the obtained thickness mapping is being evaluated retrospectively. We hope to validate it prospectively for prediction of clinical outcome the methods require improvements in accuracy and robustness.

  11. STM imaging of electrically floating islands

    NASA Astrophysics Data System (ADS)

    Realpe, H.; Shamir, N.; Mintz, M. H.; Manassen, Y.

    2006-07-01

    Appearances and disappearances of Gd islands grown on top of a W(1 1 0) substrate were observed in time scales of hours after exposing the surface to a few Langmuirs of hydrogen. The phenomenon is presented and explained in terms of (temporary) creation of electrically floating islands, due to electrical decoupling of the island and substrate by the hydrogen that diffuses into the island/substrate interface. The disappearance of such an island is explained by forming a double barrier junction consisting of two tunneling barriers in series, causing, by charging, the potential of the island to become equal to that of the tip. The island then becomes "invisible" and the tip follows the corrugation of the surface under the substrate. The reappearance follows hydrogen mobility that retains the electrical conductivity of the island-substrate interface.

  12. Phytoremediation of perchlorate by free floating macrophytes.

    PubMed

    Bhaskaran, Krishnakumar; Vijaya Nadaraja, Anupama; Tumbath, Soumya; Babu Shah, Liji; Gangadharan Puthiya Veetil, Prajeesh

    2013-09-15

    Phytoremediation of perchlorate by free floating macrophytes (Eichornia, Pistia, Salvinia and Lemna) was evaluated in this study. Among the plants tested, Pistia showed 63.8 ± 4% (w/v) removal of 5 mg/L level perchlorate in 7 days, whereas the removal was absent in other plants. Phyto-accumulation (18.2%) and rhizo-degradation (45.68%) were identified as the mechanisms involved in perchlorate removal in Pistia. Whole plant extraction yielded 45.4 μg perchlorate/g dry weight biomass in 7 days period. High intensity of light and presence of nitrate negatively affected perchlorate removal by Pistia. An enrichment of Pistia root homogenate exhibited faster reduction of perchlorate where 100mg/L of the compound was reduced completely in 48 h under anoxic condition. A novel perchlorate reducing bacterium, isolated from Pistia root homogenate enrichment was identified as Acinetobacter sp. NIIST (Genbank JX467695). PMID:23872336

  13. Floating Vitreous Cyst: Two Clinical Cases

    PubMed Central

    Lavric, Alenka; Urbancic, Mojca

    2013-01-01

    Purpose To report two cases of solitary unilateral vitreous cyst. Methods A complete ocular examination, fundus photography, B-scan ultrasound and spectral-domain optical coherence tomography were performed in both patients. Results The first patient (a 39-year-old man) presented with transient blurred vision in the right eye. The second patient (a 78-year-old man) reported transient blurred vision in the right eye when changing head position. He was referred to the Eye Hospital because of vitreomacular traction in the other eye. After examination, a diagnosis of vitreous cyst was made in both cases. Conclusions Vitreous cysts are rare clinical findings. They can occur in normal eyes or in eyes with certain ocular pathologies. When a cyst floats into the visual axis area, it can disturb visual function; therefore, patients usually report transient blurring of vision. A prompt clinical examination is necessary for differentiating this rare condition. PMID:24348410

  14. Fresh look at floating shock fitting

    NASA Technical Reports Server (NTRS)

    Hartwich, PETER-M.

    1990-01-01

    A fast implicit upwind procedure for the two-dimensional Euler equations is described that allows accurate computations of shocked flows on nonadapted meshes. Away from shocks, the second-order accurate upwinding is based on the split-coefficient-matrix (SCM) method. In the presence of shocks, the difference stencils are modified using a floating shock fitting technique. Rapid convergence to steady-state solutions is attained with a diagonalized approximate factorization (AF) algorithm. Results are presented for Riemann's problem, for a regular shock reflection at an inviscid wall, for supersonic flow past a cylinder, and for a transonic airfoil. All computed shocks are ideally sharp and in excellent agreement with other numerical results or 'exact' solutions. Most importantly, this has been accomplished on unusually crude meshes without any attempt to align grid lines with shock fronts or to cluster grid lines around shocks.

  15. Capillary self-assembly of floating bodies

    NASA Astrophysics Data System (ADS)

    Jung, Sunghwan; Thompson, Paul; Bush, John

    2007-11-01

    We study the self-assembly of bodies supported on the water surface by surface tension. Attractive and repulsive capillary forces exist between menisci of, respectively, the same and opposite signs. In nature, floating objects (e.g. mosquito larvae) thus interact through capillary forces to form coherent packings on the water surface. We here present the results of an experimental investigation of such capillary pattern formation. Thin elliptical metal sheets were designed to have variable shape, flexibility and mass distribution. On the water surface, mono-, bi-, or tri-polar menisci could thus be achieved. The influence of the form of the menisci on the packings arising from the interaction of multiple floaters is explored. Biological applications are discussed.

  16. Nuclear Security for Floating Nuclear Power Plants

    SciTech Connect

    Skiba, James M.; Scherer, Carolynn P.

    2015-10-13

    Recently there has been a lot of interest in small modular reactors. A specific type of these small modular reactors (SMR,) are marine based power plants called floating nuclear power plants (FNPP). These FNPPs are typically built by countries with extensive knowledge of nuclear energy, such as Russia, France, China and the US. These FNPPs are built in one country and then sent to countries in need of power and/or seawater desalination. Fifteen countries have expressed interest in acquiring such power stations. Some designs for such power stations are briefly summarized. Several different avenues for cooperation in FNPP technology are proposed, including IAEA nuclear security (i.e. safeguards), multilateral or bilateral agreements, and working with Russian design that incorporates nuclear safeguards for IAEA inspections in non-nuclear weapons states

  17. Spectral analysis of Floating Car Data

    NASA Astrophysics Data System (ADS)

    Gössel, F.; Michler, E.; Wrase, B.

    2003-05-01

    Floating Car Data (FCD) are one important data source in traffic telematic systems. The original variable in these systems is the vehicle velocity. The paper analyses the measured value "vehicle velocity" by methods of information technology. Consequences for processing, transmission and storage of FCD under condition of limited resources are discussed. Starting point of the investigation is the analysis of spectral characteristics of velocity-time-profiles. The spectra are determined by the Discrete Fourier Transform (DFT) from measurement data and simulation data of a microscopic traffic model. One essential property of velocity-time-profiles is their low-pass characteristic. The resulting cut-off-frequency is comparatively small and depends on the traffic scenario. Conclusions concerning the necessary sample rate in FCD systems and the processing of raw data are discussed. Finally the transinformation of velocity-time-profiles is analysed. This results in similar values for an optimal sample rate of FCD systems under condition of limited transmission capacity.

  18. Multibody dynamic simulation of knee contact mechanics

    PubMed Central

    Bei, Yanhong; Fregly, Benjamin J.

    2006-01-01

    Multibody dynamic musculoskeletal models capable of predicting muscle forces and joint contact pressures simultaneously would be valuable for studying clinical issues related to knee joint degeneration and restoration. Current three-dimensional multi-body knee models are either quasi-static with deformable contact or dynamic with rigid contact. This study proposes a computationally efficient methodology for combining multibody dynamic simulation methods with a deformable contact knee model. The methodology requires preparation of the articular surface geometry, development of efficient methods to calculate distances between contact surfaces, implementation of an efficient contact solver that accounts for the unique characteristics of human joints, and specification of an application programming interface for integration with any multibody dynamic simulation environment. The current implementation accommodates natural or artificial tibiofemoral joint models, small or large strain contact models, and linear or nonlinear material models. Applications are presented for static analysis (via dynamic simulation) of a natural knee model created from MRI and CT data and dynamic simulation of an artificial knee model produced from manufacturer’s CAD data. Small and large strain natural knee static analyses required 1 min of CPU time and predicted similar contact conditions except for peak pressure, which was higher for the large strain model. Linear and nonlinear artificial knee dynamic simulations required 10 min of CPU time and predicted similar contact force and torque but different contact pressures, which were lower for the nonlinear model due to increased contact area. This methodology provides an important step toward the realization of dynamic musculoskeletal models that can predict in vivo knee joint motion and loading simultaneously. PMID:15564115

  19. Plastinated Knee Specimens: A Novel Educational Tool

    PubMed Central

    Neha; Lalwani, Sanjeev; Dhingra, Renu

    2013-01-01

    Introduction: During the routine dissection of knee joints in an anatomy dissection hall, it was observed that the specimens had deteriorated overtime, due to their repeated handling and the use of high concentrations of formalin for their fixation. In order to stop their further deterioration, we decided to plastinate these specimens. Thus, the present study was undertaken to prepare plastinated knee specimens from old embalmed cadavers and to compare them with freshly fixed, plastinated specimens. Objectives: 1. To plastinate old embalmed and fresh formalin fixed knee regions. 2. To demonstrate the extra and the intracapsular structures around both the plastinated knee regions. 3. To compare their morphological features in terms of their colours, dilatation and flexibility. Methods: A total of 15 knee joint specimens from among fresh formalin (5-8%) fixed (group I) and old embalmed bodies (group II) were collected, washed and plastinated by using the standard S-10 silicon technique and they were compared for their colours, dilatation and flexibility. Results: All the plastinated specimens showed an accurate reproduction of the tissue details that were comparable to those of the natural unfixed specimens. A comparison among the two groups showed a significant difference in terms of the colour, dilatation and the flexibility of the specimens. The plastinated knee joint specimens from group I were of good quality, with negligible shrinkage, more flexibility and well preserved morphologies. Conclusion: Plastinated knee specimens can serve as an excellent educational tool for the undergraduate and postgraduate students of anatomy, radiology and orthopaedics, as they are dry, odourless and nontoxic, with a good structural preservation and a higher instructional value. The fresh knee regions, when they were plastinated, were aesthetically superior in terms of their colours, dilatation and flexibility, thus making them ideal for teaching and hands-on experiences. PMID

  20. Proximal tibial fracture following total knee arthroplasty.

    PubMed

    Krause, Heike; Dunleavy, Kim

    2011-09-01

    The patient was a 74-year-old man, with a history of total knee arthoplasty 14 years earlier, after having sustained a pathological fracture of the proximal diaphysis of the left tibia following a fall. Given the unstable nature of the fracture and the severe osteolysis noted below the total knee arthroplasty, surgical management 1 day after the fall entailed packing cancellous bone graft into the defect and realigning the fracture. PMID:21885911

  1. Total knee arthroplasty using subvastus approach in stiff knee: A retrospective analysis of 110 cases

    PubMed Central

    Shah, Nilen A; Patil, Hitendra Gulabrao; Vaishnav, Vinod O; Savale, Abhijit

    2016-01-01

    Background: Subvastus approach used in total knee arthroplasty (TKA) is known to produce an earlier recovery but is not commonly utilized for TKA when the preoperative range of motion (ROM) of the knee is limited. Subvastus approach is known for its ability to give earlier recovery due to less postoperative pain and early mobilization (due to rapid quadriceps recovery). Subvastus approach is considered as a relative contraindication for TKA in knees with limited ROM due to difficulty in exposure which can increase risk of complications such as patellar tendon avulsion or medial collateral injury. Short stature and obesity are also relative contraindications. Tarabichi successfully used subvastus approach in knees with limited preoperative ROM. However, there are no large series in literature with the experience of the subvatus approach in knees with limited preoperative ROM. We are presenting our experience of the subvastus approach for TKA in knees with limited ROM. Materials and Methods: We conducted retrospective analysis of patients with limited preoperative ROM (flexion ≤90°) of the knee who underwent TKA using subvastus approach and presenting the 2 years results. There were a total 84 patients (110 knees) with mean age 64 (range 49–79 years) years. The mean preoperative flexion was 72° (range 40°–90°) with a total ROM of 64° (range 36°–90°). Results: Postoperatively knee flexion improved by mean 38° (P < 0.05) which was significant as assed by Student's t- test. The mean knee society score improved from 36 (range 20–60) to 80 (range 70–90) postoperatively (P < 0.05). There was one case of partial avulsion of patellar tendon from the tibial tubercle. Conclusions: We concluded that satisfactory results of TKA can be obtained in knees with limited preoperative ROM using subvastus approach maintaining the advantages of early mobilization. PMID:27053806

  2. Tank Tests of Models of Floats for Single-float Seaplanes First Series.

    NASA Technical Reports Server (NTRS)

    Parkinson, J B

    1936-01-01

    Large models of the Mark V and Mark VI floats used for single float seaplanes (National Advisory Committee for Aeronautics (NACA) models 41-A and 41-B, respectively) were tested in the NACA tank to provide general test data for typical single floats and a basis for possible improvements of their form. The resistance of model 41-B was greater than that of model 41-A, either when free to trim or at the best trim angle for each. The resistance of model 35-B (a pointed step hull tested free to trim) was less than either of the models at the hump speed, greater at intermediate planing speeds, and less at the speeds and loads near get-away, although the spray was generally worse owing to the absence of transverse flare. The results of the fixed-trim tests of model 41-A were cross plotted to obtain data at the angle for zero trimming moment and at the best trim angle. The trims assumed by models 41-A and 41-B, when tested free to trim, were found to be excessive at the hump speed. The corresponding trim of model 35-B was found to be approximately 3 degrees lower because of the lower angle of afterbody keel used in this model, and the maximum hump resistance was 15 percent lower.

  3. Muscle Impairments in Patients With Knee Osteoarthritis

    PubMed Central

    Alnahdi, Ali H.; Zeni, Joseph A.; Snyder-Mackler, Lynn

    2012-01-01

    Context: Muscle impairments associated with knee osteoarthritis (OA) are the primary underlying cause of functional limitations. Understanding the extent of muscle impairments, its relationship with physical function and disease progression, and the evidence behind exercise therapy that targets muscle impairments is crucial. Evidence Acquisition: An electronic search for relevant articles using MEDLINE and CINHAL databases up to September 2011 was performed. In addition to the electronic search, retrieved articles were searched manually for relevant studies. Results: Quadriceps, hamstrings, and hip muscles are significantly impaired in subjects with knee OA compared with age-matched controls. Muscle strength, especially quadriceps, is a major determinant of both performance-based and self-reported physical function. Whether stronger quadriceps is protective against knee OA onset and progression is not clear. Exercise therapy, including global and targeted resistance training, is effective in reducing pain and improving function in subjects with knee OA. Conclusions: Subjects with knee OA have significant muscle impairments. These muscle impairments affect physical function and should be targeted in therapy. Further research is needed to explore the relationship between quadriceps strength and knee OA initiation and progression and to determine the optimal exercise prescription that augments outcomes in this patient population. PMID:23016099

  4. [Arthritis of the Medial Knee Joint Compartment].

    PubMed

    Matziolis, G; Röhner, E

    2015-10-01

    23 % of all persons older than 65 years suffer from osteoarthritis of the medial compartment of the knee joint, a very common situation in orthopaedic practice 1. As a result of the demographic trend the number of patients is expected to increase in the future. Based on specific joint biomechanics and kinematics the medial knee joint compartment is more frequently affected than the lateral. Only an understanding of the functional anatomy and underlying pathology allows a critical evaluation of different available conservative and operative treatment options. This article gives an overview of diagnostic and therapeutic strategies of osteoarthritis of the medial knee joint. Frequently performed surgeries, e.g. high tibial osteotomy (HTO), unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) will be presented in a comparative manner. The actual scientific evidence will be given with the goal of an evidence based therapy that is adopted to stage and pathology of osteoarthritis of the medial compartment of the knee joint. PMID:26451864

  5. Porous carrier based floating granular delivery system of repaglinide.

    PubMed

    Jain, Sunil K; Agrawal, Govind P; Jain, Narendra K

    2007-04-01

    A floating granular delivery system consisting of calcium silicate (CS) as porous carrier; repaglinide (Rg), an oral hypoglycemic agent; and hydroxypropyl methylcellulose K4M (HPMC K4M), ethyl cellulose (EC) and carbopol 940 (CP940) as matrix forming polymers was prepared and evaluated for its gastro-retentive and controlled release properties. The effect of various formulation and process variables on the particle morphology, micromeritic properties, in vitro floating behavior, drug content (%) and in vitro drug release was studied. The transit of floating granules of optimized formulation in the gastrointestinal (GI) tract was monitored by gamma scintigraphy in albino rabbits. The optimized formulation was compared in vivo with lactose granules (RgSCLG) prepared from identical polymers with their optimized composition ratio. Repaglinide-loaded optimized formulation was orally administered to albino rabbits and blood samples collected were used to determine pharmacokinetic parameters of Rg from floating granular formulation. Results were compared with pharmacokinetic parameters of marketed tablet formulation of Rg. The optimized formulation (RgSCG4) demonstrated favorable in vitro floating and release characteristics. Prolonged gastric residence time (GRT) of over 6 hr was achieved in all subjects for calcium silicate based floating granules of Rg. The relative bioavailability of Rg-loaded floating granules increased 3.8-fold in comparison to that of its marketed capsule. The designed system, combining excellent buoyant ability and suitable drug release pattern, offered clear advantages in terms of increased bioavailability of repaglinide. PMID:17523003

  6. WindWaveFloat (WWF): Final Scientific Report

    SciTech Connect

    Alla Weinstein; Roddier, Dominique; Banister, Kevin

    2012-03-30

    Principle Power Inc. and National Renewable Energy Lab (NREL) have completed a contract to assess the technical and economic feasibility of integrating wave energy converters into the WindFloat, resulting in a new concept called the WindWaveFloat (WWF). The concentration of several devices on one platform could offer a potential for both economic and operational advantages. Wind and wave energy converters can share the electrical cable and power transfer equipment to transport the electricity to shore. Access to multiple generation devices could be simplified, resulting in cost saving at the operational level. Overall capital costs may also be reduced, provided that the design of the foundation can be adapted to multiple devices with minimum modifications. Finally, the WindWaveFloat confers the ability to increase energy production from individual floating support structures, potentially leading to a reduction in levelized energy costs, an increase in the overall capacity factor, and greater stability of the electrical power delivered to the grid. The research conducted under this grant investigated the integration of several wave energy device types into the WindFloat platform. Several of the resulting system designs demonstrated technical feasibility, but the size and design constraints of the wave energy converters (technical and economic) make the WindWaveFloat concept economically unfeasible at this time. Not enough additional generation could be produced to make the additional expense associated with wave energy conversion integration into the WindFloat worthwhile.

  7. Greater Step Widths Reduce Internal Knee Abduction Moments in Medial Compartment Knee Osteoarthritis Patients During Stair Ascent.

    PubMed

    Paquette, Max R; Klipple, Gary; Zhang, Songning

    2015-08-01

    Increased step widths have been shown to reduce peak internal knee abduction moments in healthy individuals but not in knee osteoarthritis patients during stair descent. This study aimed to assess effects of increased step widths on peak knee abduction moments and associated variables in adults with medial knee osteoarthritis and healthy older adults during stair ascent. Thirteen healthy older adults and 13 medial knee osteoarthritis patients performed stair ascent using preferred, wide, and wider step widths. Three-dimensional kinematics and ground reaction forces (GRFs) using an instrumented staircase were collected. Increased step width reduced first and second peak knee abduction moments, and knee abduction moment impulse. In addition, frontal plane GRF at time of first and second peak knee abduction moment and lateral trunk lean at time of first peak knee abduction moment were reduced with increased step width during stair ascent in both groups. Knee abduction moment variables were not different between knee osteoarthritis patients and healthy controls. Our findings suggest that increasing step width may be an effective simple gait alteration to reduce knee abduction moment variables in both knee osteoarthritis and healthy adults during stair ascent. However, long term effects of increasing step width during stair ascent in knee osteoarthritis and healthy adults remain unknown. PMID:25781222

  8. Active knee motion after cruciate ligament rupture. Stereoradiography.

    PubMed

    Kärrholm, J; Selvik, G; Elmqvist, L G; Hansson, L I

    1988-04-01

    In 10 patients with an old injury of the anterior cruciate ligament, the three-dimensional movements of the knee joint were studied when the patients flexed their knees. Tibial motions were recorded using roentgen stereophotogrammetric analysis. Internal rotation and adduction of the tibia were reduced in the injured knees when compared with the intact knees; during flexion of the knee joint, the tibial intercondylar eminence occupied a more lateral and posterior position on the injured side. Our results may indicate that the knee joint is continuously exposed to abnormal stresses when the anterior cruciate ligament is torn. PMID:3364185

  9. The influence of joint line position on knee stability after condylar knee arthroplasty.

    PubMed

    Martin, J W; Whiteside, L A

    1990-10-01

    Using a special knee-testing device, ten knees obtained at autopsy were subjected to varus-valgus, anterior-posterior, and flexion-rotation analysis in the intact state and after total knee arthroplasty. The ten knees showed no significant change in stability after knee replacement when the joint line was maintained in its natural position. When the femoral component was repositioned 5 mm proximally and 5 mm anteriorly, a significant increase in laxity occurred during midflexion. When the joint line was shifted 5 mm distal and 5 mm posterior to its anatomic location, significant tightening occurred in midrange of motion. Coupled rotation of the tibia with knee flexion was decreased after surgery in all knees with no specific relationship to joint line position. Coupled rotation with varus-valgus testing, however, remained within the normal range through the first 30 degrees of flexion only when the joint line was restored to its normal anatomic position. Stability in condylar knee arthroplasty is in part dependent on position of the joint line. Surgical techniques that rely on restoring the flexion and extension gap without regard to joint line position may result in alteration of varus-valgus or anterior-posterior displacement in midrange flexion. PMID:2208849

  10. An improved OpenSim gait model with multiple degrees of freedom knee joint and knee ligaments.

    PubMed

    Xu, Hang; Bloswick, Donald; Merryweather, Andrew

    2015-08-01

    Musculoskeletal models are widely used to investigate joint kinematics and predict muscle force during gait. However, the knee is usually simplified as a one degree of freedom joint and knee ligaments are neglected. The aim of this study was to develop an OpenSim gait model with enhanced knee structures. The knee joint in this study included three rotations and three translations. The three knee rotations and mediolateral translation were independent, with proximodistal and anteroposterior translations occurring as a function of knee flexion/extension. Ten elastic elements described the geometrical and mechanical properties of the anterior and posterior cruciate ligaments (ACL and PCL), and the medial and lateral collateral ligaments (MCL and LCL). The three independent knee rotations were evaluated using OpenSim to observe ligament function. The results showed that the anterior and posterior bundles of ACL and PCL (aACL, pACL and aPCL, pPCL) intersected during knee flexion. The aACL and pACL mainly provided force during knee flexion and adduction, respectively. The aPCL was slack throughout the range of three knee rotations; however, the pPCL was utilised for knee abduction and internal rotation. The LCL was employed for knee adduction and rotation, but was slack beyond 20° of knee flexion. The MCL bundles were mainly used during knee adduction and external rotation. All these results suggest that the functions of knee ligaments in this model approximated the behaviour of the physical knee and the enhanced knee structures can improve the ability to investigate knee joint biomechanics during various gait activities. PMID:24611807

  11. Strongly Emitting Surfaces Unable to Float below Plasma Potential

    NASA Astrophysics Data System (ADS)

    Campanell, M. D.; Umansky, M. V.

    2016-02-01

    An important unresolved question in plasma physics concerns the effect of strong electron emission on plasma-surface interactions. Previous papers reported solutions with negative and positive floating potentials relative to the plasma edge. The two models give very different predictions for particle and energy balance. Here we show that the positive potential state is the only possible equilibrium in general. Even if a negative floating potential existed at t =0 , the ionization collisions near the surface will force a transition to the positive floating potential state. This transition is demonstrated with a new simulation code.

  12. Strongly Emitting Surfaces Unable to Float below Plasma Potential

    DOE PAGESBeta

    Campanell, M. D.; Umansky, M. V.

    2016-02-25

    One important unresolved question in plasma physics concerns the effect of strong electron emission on plasma-surface interactions. Previous papers reported solutions with negative and positive floating potentials relative to the plasma edge. For these two models a very different predictions for particle and energy balance is given. Here we show that the positive potential state is the only possible equilibrium in general. Even if a negative floating potential existed at t=0, the ionization collisions near the surface will force a transition to the positive floating potential state. Moreover, this transition is demonstrated with a new simulation code.

  13. Defining the IEEE-854 floating-point standard in PVS

    NASA Technical Reports Server (NTRS)

    Miner, Paul S.

    1995-01-01

    A significant portion of the ANSI/IEEE-854 Standard for Radix-Independent Floating-Point Arithmetic is defined in PVS (Prototype Verification System). Since IEEE-854 is a generalization of the ANSI/IEEE-754 Standard for Binary Floating-Point Arithmetic, the definition of IEEE-854 in PVS also formally defines much of IEEE-754. This collection of PVS theories provides a basis for machine checked verification of floating-point systems. This formal definition illustrates that formal specification techniques are sufficiently advanced that is is reasonable to consider their use in the development of future standards.

  14. Float level switch for a nuclear power plant containment vessel

    DOEpatents

    Powell, James G.

    1993-01-01

    This invention is a float level switch used to sense rise or drop in water level in a containment vessel of a nuclear power plant during a loss of coolant accident. The essential components of the device are a guide tube, a reed switch inside the guide tube, a float containing a magnetic portion that activates a reed switch, and metal-sheathed, ceramic-insulated conductors connecting the reed switch to a monitoring system outside the containment vessel. Special materials and special sealing techniques prevent failure of components and allow the float level switch to be connected to a monitoring system outside the containment vessel.

  15. Float level switch for a nuclear power plant containment vessel

    DOEpatents

    Powell, J.G.

    1993-11-16

    This invention is a float level switch used to sense rise or drop in water level in a containment vessel of a nuclear power plant during a loss of coolant accident. The essential components of the device are a guide tube, a reed switch inside the guide tube, a float containing a magnetic portion that activates a reed switch, and metal-sheathed, ceramic-insulated conductors connecting the reed switch to a monitoring system outside the containment vessel. Special materials and special sealing techniques prevent failure of components and allow the float level switch to be connected to a monitoring system outside the containment vessel. 1 figures.

  16. Open source high performance floating-point modules.

    SciTech Connect

    Underwood, Keith Douglas

    2006-02-01

    Given the logic density of modern FPGAs, it is feasible to use FPGAs for floating-point applications. However, it is important that any floating-point units that are used be highly optimized. This paper introduces an open source library of highly optimized floating-point units for Xilinx FPGAs. The units are fully IEEE compliant and achieve approximately 230 MHz operation frequency for double-precision add and multiply in a Xilinx Virtex-2-Pro FPGA (-7 speed grade). This speed is achieved with a 10 stage adder pipeline and a 12 stage multiplier pipeline. The area requirement is 571 slices for the adder and 905 slices for the multiplier.

  17. Recent advances in gastric floating drug delivery technology: a review.

    PubMed

    Pahwa, Rakesh; Bisht, Seema; Kumar, Vipin; Kohli, Kanchan

    2013-06-01

    Gastric floating drug delivery systems have been an avenue of considerable interest in terms of their immense potential for better pharmacotherapeutic interventions along with site-specific absorption. These buoyant systems significantly enhance the bioavailability and controlled delivery of several drug molecules. Scientific investigators have also carried out substantial research endeavours worldwide in order to design a more systematic and intellectual floating systems. The present manuscript is an attempt to highlight numerous recent advancements in the design of gastric floating drug delivery systems along with various available commercial preparations. Salient applications, characterization aspects and future perspectives of these multifarious systems have also been addressed. PMID:23808593

  18. Radiation Issues and Applications of Floating Gate Memories

    NASA Technical Reports Server (NTRS)

    Scheick, L. Z.; Nguyen, D. N.

    2000-01-01

    The radiation effects that affect various systems that comprise floating gate memories are presented. The wear-out degradation results of unirradiated flash memories are compared to irradiated flash memories. The procedure analyzes the failure to write and erase caused by wear-out and degradation of internal charge pump circuits. A method is described for characterizing the radiation effects of the floating gate itself. The rate dependence, stopping power dependence, SEU susceptibility and applications of floating gate in radiation environment are presented. The ramifications for dosimetry and cell failure are discussed as well as for the long term use aspects of non-volatile memories.

  19. Shifting epidemiology of Flaviviridae.

    PubMed

    Petersen, Lyle R; Marfin, Anthony A

    2005-04-01

    The dengue, West Nile, Japanese encephalitis and yellow fever viruses are important mosquito-borne viruses whose epidemiology is shifting in response to changing societal factors, such as increasing commerce, urbanization of rural areas, and population growth. All four viruses are expanding geographically, as exemplified by the emergence of West Nile virus in the Americas and Japanese encephalitis virus in Australasia. The large, recent global outbreaks of severe neurological disease caused by West Nile virus, the increasing frequency of dengue hemorrhagic fever outbreaks in the Americas, and the emergence of yellow fever virus vaccination-associated viscerotropic disease, are new clinical epidemiologic trends. These worrisome epidemiologic trends will probably continue in coming decades, as a reversal of their societal and biological drivers is not in sight. Nevertheless, the substantial reductions in Japanese encephalitis virus incidence resulting from vaccination programs and economic development in some Asian countries provide some encouragement within this overall guarded outlook. PMID:16225801

  20. Evaluation of a knee-kicker bumper design for reducing knee morbidity among carpet layers.

    PubMed

    Huang, Wan-Fu; Wu, Chih-Fu

    2012-09-01

    Carpet layers have a high prevalence of occupational knee morbidity. One of the main causes is that they need to frequently 'kick' the bumper on the rear end of the knee kicker with one knee when laying a carpet. Considering the bumper's marked effects on kicking force transmission and safety, this study aims to improve the design of the knee-kicker bumper by reducing the risk factors. An improved pendulum-type impact-testing platform was designed as an evaluative apparatus, with the impulse and the coefficient of restitution serving as evaluative criteria. The newly developed bumper has improved firmness from drilled blind holes and an increase in effective forward force of 15%-138%, which implies lower operational demands and a lighter knee burden (i.e., less kicking energy results in the same work efficiency), and a softer contact surface that enhances operating comfort. The newly designed kicker was positively reviewed by subjects. PMID:22326189

  1. Lateral dislocation of the knee joint after total knee arthroplasty: a case report

    PubMed Central

    Ugutmen, Ender; Ozkan, Korhan; Unay, Koray; Mahirogullari, Mahir; Eceviz, Engin; Taser, Omer

    2008-01-01

    Background Total knee arthroplasty (TKA) is a successful therapy for functional improvement and pain relief in advanced symptomatic degeneration of the knee joint. But it can be associated with many complications, one of which is instability. Case presentation A 70-year-old woman was referred to our hospital because of right knee dislocation after TKA was performed on her right knee due to severe varus deformity and flexion contracture. This instability was caused by persistent MCL tightness and iatrogenic lateral collateral, arcuate ligament, and popliteus tendon injury. The torn lateral collateral ligament and arcuate ligament were sutured with no. 2 non-absorbable (Ethibond) sutures with plication of the posterolateral knee capsule. A deep-dish liner was inserted to optimize soft tissue tension. Conclusion This is a very severe complication, and surgeons must be cautious about ligament balancing and soft tissue resection during TKA for severe varus and valgus deformities. PMID:18687153

  2. Epidemiology of Lung Cancer.

    PubMed

    Mao, Yousheng; Yang, Ding; He, Jie; Krasna, Mark J

    2016-07-01

    Lung cancer has been transformed from a rare disease into a global problem and public health issue. The etiologic factors of lung cancer become more complex along with industrialization, urbanization, and environmental pollution around the world. Currently, the control of lung cancer has attracted worldwide attention. Studies on the epidemiologic characteristics of lung cancer and its relative risk factors have played an important role in the tertiary prevention of lung cancer and in exploring new ways of diagnosis and treatment. This article reviews the current evolution of the epidemiology of lung cancer. PMID:27261907

  3. 46 CFR 160.027-3 - Additional requirements for life floats.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 6 2012-10-01 2012-10-01 false Additional requirements for life floats. 160.027-3..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Floats for Merchant Vessels § 160.027-3 Additional requirements for life floats. (a) Each life float must have a platform...

  4. 46 CFR 160.027-3 - Additional requirements for life floats.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Additional requirements for life floats. 160.027-3..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Floats for Merchant Vessels § 160.027-3 Additional requirements for life floats. (a) Each life float must have a platform...

  5. Usefulness of the Korean Knee Score for Evaluation of the Results of Total Knee Arthroplasty

    PubMed Central

    Lee, Jin Kyu; Shim, Ji-Hoon; Chung, Kyu-Sung

    2015-01-01

    Purpose The Korean Knee score (KKS) was designed to reflect the floor-sitting lifestyle that necessitates high knee flexion. The purpose of this study is to assess whether the KKS reflects the floor-sitting lifestyle more accurately than the previously developed Knee Society clinical rating system. In addition, the presence of ceiling effects was compared between the two rating systems. Materials and Methods Eighty-one consecutive patients (120 knees) who were assessed regularly after total knee arthroplasty (TKA) on an outpatient basis between January 2012 and December 2012 were enrolled. All patients were asked to complete a questionnaire to assess the Knee Society Knee score (KSKS), Knee Society Function score (KSFS), and KKS. Results At the final follow-up, the mean KSKS, KSFS, and KKS were 91.2, 86.0, and 70.1, respectively, and the scores were similar between the ≥125° maximum flexion group and <125° maximum flexion group. However, the 'floor life' subdomain score of the KKS was significantly higher in the >125° maximum flexion group (15.13 vs. 11.24, p=0.001). The number of cases with the highest possible score was 24 (20%) for the KSKS and 47 (39%) for the KSFS, whereas none of the cases obtained the highest possible KKS. According to the standard deviation method, more substantial ceiling effects were present in the KSKS (83 cases, 69.1%) and KSFS (67 cases, 55.8%) than in the KKS (23 cases, 19.2%). Conclusions Although, the KKS was effective in reducing the ceiling effect, it demonstrated limited improvement in assessing the ability to perform high knee flexion after TKA. However, the 'floor life' subdomain of KSS appeared to be valid for evaluating high flexion of the knee. PMID:25750889

  6. [Biomechanics of the knee joint].

    PubMed

    Witzel, U

    1993-01-01

    The capsular and ligamentous structures as control system of a healthy knee-joint supported by the muscular system are responsible for the rolling and gliding motion of the femoral condyles on the tibial plateau. Both the condyles and the tibial plateau have individually developed but to each other adjusted shapes and fine structures thereby. These structures consist of hyaline cartilage at their three-dimensional surfaces and of closely packed fibrils (lamina splendens) as the final gliding zone for tensile load. The orientation of the collagenous fibres can be made visible by split lines. The chondral surfaces are indirectly in contact to each other and orthogonally stressed at the particular point of contact. The indirect contact of the cartilaginous surfaces happens under interposition of the menisci. The meniscus serves to reduce and equalize the surface pressure by its own projected surface on the one hand and by maintaining of a hydraulic pressure of the synovial fluid on the other hand. Deviations of the condylar position as a result on ligamentous instabilities or ruptures with a following occurring loss of congruence, meniscal lesions or traumatic ruptures lead to a rapid discharge of the synovial fluid under load. The result is a hydraulic head loss with direct contact of the chondral surfaces under stress leading to arthrotic deformations. Severe arthrotic deformations or very much every meniscectomy produce intraarticular lumped loads resulting in a hyper-physiologic chondral pressure and malnutrition thereby. Further on there develop subchondral stress concentrations (caused by the lumped loads) leading to osseous damages, too. MR-pictures can make visible these damages. Chondromalacia, fissure or even chondrolysis are arthroscopically detectable sometimes. As after-effects of deficient knee ligaments occur pathological deviations of the femoral condyles and resulting destructions of the articular surfaces under stress enormously intensified by

  7. Rib stress fractures among rowers: definition, epidemiology, mechanisms, risk factors and effectiveness of injury prevention strategies.

    PubMed

    McDonnell, Lisa K; Hume, Patria A; Nolte, Volker

    2011-11-01

    velocity, sequential movement patterns, higher elbow-flexion to knee-extension strength ratios, higher seat-to-handle velocity during the initial drive, or higher shoulder angle excursion may result in RSF. Gearing may indirectly affect rib loading. Increased risk may be due to low calcium, low vitamin D, eating disorders, low testosterone or use of depot medroxyprogesterone injections. Injury management involves 1-2 weeks cessation of rowing with analgesic modalities followed by a slow return to rowing with low-impact intensity and modified pain-free training. Some evidence shows injury prevention strategies should focus on strengthening the serratus anterior, strengthening leg extensors, stretching the lumbar spine, increasing hip joint flexibility, reducing excessive protraction, training with ergometers on slides or floating-head ergometers, and calcium and vitamin D supplementation. Future research should focus on the epidemiology of RSF over 4-year Olympic cycles in elite rowers, the aetiology of the condition, and the effectiveness of RSF prevention strategies for injury incidence and performance in rowing. PMID:21985212

  8. Digital microfluidics with a magnetically actuated floating liquid marble.

    PubMed

    Khaw, Mei Kum; Ooi, Chin Hong; Mohd-Yasin, Faisal; Vadivelu, Raja; John, James St; Nguyen, Nam-Trung

    2016-06-21

    Controlled actuation of a floating liquid marble, a liquid droplet coated with hydrophobic particles floating on another liquid surface, is a potential digital microfluidics platform for the transport of aqueous solution with minimal volume loss. This paper reports our recent investigation on the magnetic actuation of floating liquid marbles filled with magnetic particles. The magnetic force and frictional force acting on the floating liquid marble determine the horizontal movement of the marble. We varied the magnetic flux density, flux density gradient, concentration of magnetic particles and speed of the marble to elucidate the relationship between the acting forces. We subsequently determined the suitable operating conditions for the actuation and derived the scaling laws for the actuation parameters. PMID:27191398

  9. Preview of Mars Curiosity Parade Float - Duration: 33 seconds.

    NASA Video Gallery

    Jim Green, Director of the Science Mission Directorate Planetary Systems Division at NASA Headquarters, describes the replica of the Mars Curiosity Rover on the second NASA float in Monday's inaugu...

  10. 26. Mechanical float gages used to monitor level of water ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. Mechanical float gages used to monitor level of water in the filtration bed reservoir. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  11. Preparation and evaluation of gastroretentive floating tablets of acyclovir.

    PubMed

    Garg, Rajeev; Gupta, G D

    2009-10-01

    The present study performed by preparation and evaluation of floating tablets of Acyclovir as model drug for prolongation of gastric residence time. Floating effervescent tablets were formulated by various materials like hydroxypropyl methylcellulose K 4M, K 15M, psyllium husk, swelling agent as crospovidone and microcrystalline cellulose and gas generating agent like sodium bicarbonate and citric acid and evaluated for floating properties, swelling characteristics and in vitro drug release studies. Floating noneffervescent tablets were prepared by polypropylene foam powder and different matrix forming polymers like HPMC K 4M, Carbopol 934P, xanthan gum and sodium alginate. In vitro drug release studies were performed and drug release kinetics evaluated using the linear regression method was found to follow both the Higuchi and the Korsmeyer and Peppas equation. The drug release mechanism was found fickian type in most of the formulations. PMID:19751200

  12. 50. (no plate) Lens, lens pedestal, mercury float, drawing # ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. (no plate) Lens, lens pedestal, mercury float, drawing # 3101, sheet 1 of 2. Approved April 6, 1928. - Block Island Southeast Light, Spring Street & Mohegan Trail at Mohegan Bluffs, New Shoreham, Washington County, RI

  13. 51. (no plate) Lens, lens pedestal, mercury float, shade holder ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. (no plate) Lens, lens pedestal, mercury float, shade holder installation, drawing # 3101, sheet 2 of 2. Approved April 6, 1928. - Block Island Southeast Light, Spring Street & Mohegan Trail at Mohegan Bluffs, New Shoreham, Washington County, RI

  14. High voltage switches having one or more floating conductor layers

    SciTech Connect

    Werne, Roger W.; Sampayan, Stephen; Harris, John Richardson

    2015-11-24

    This patent document discloses high voltage switches that include one or more electrically floating conductor layers that are isolated from one another in the dielectric medium between the top and bottom switch electrodes. The presence of the one or more electrically floating conductor layers between the top and bottom switch electrodes allow the dielectric medium between the top and bottom switch electrodes to exhibit a higher breakdown voltage than the breakdown voltage when the one or more electrically floating conductor layers are not present between the top and bottom switch electrodes. This increased breakdown voltage in the presence of one or more electrically floating conductor layers in a dielectric medium enables the switch to supply a higher voltage for various high voltage circuits and electric systems.

  15. 16. EAST ELEVATION OF FLOAT HOUSE AND FISH WATER RELEASE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. EAST ELEVATION OF FLOAT HOUSE AND FISH WATER RELEASE OUTLET. PART OF ENERGY DISSIPATING BAFFLE PIER SYSTEM IS VISIBLE AT LEFT. - Pit 4 Diversion Dam, Pit River west of State Highway 89, Big Bend, Shasta County, CA

  16. Floating Crane YD82 general view. Date taken unknown. Taken ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Floating Crane YD-82 - general view. Date taken unknown. Taken by Pearl Harbor photographer. Crane Division Collection - U.S. Naval Base, Pearl Harbor, Exterior Cranes, Waterfront Crane Track System, Pearl City, Honolulu County, HI

  17. Knee Injuries and Disorders - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Are Here: Home → Multiple Languages → All Health Topics → Knee Injuries and Disorders URL of this page: https://medlineplus. ... V W XYZ List of All Topics All Knee Injuries and Disorders - Multiple Languages To use the sharing ...

  18. Getting Active After Knee Replacement Might Raise Hip Fracture Risk

    MedlinePlus

    ... Getting Active After Knee Replacement Might Raise Hip Fracture Risk Swedish study found that people with new knees had slight uptick in spinal fractures, too To use the sharing features on this ...

  19. Hip or knee replacement - before - what to ask your doctor

    MedlinePlus

    ... replace all or part of your hip or knee joint with an artificial device (a prosthesis). Below are some questions you may want to ask your health care provider to help you prepare for your hip or knee replacement.

  20. Hip or knee replacement - after - what to ask your doctor

    MedlinePlus

    ... Below are some questions you may want to ask your health care provider to help you take ... What to ask your doctor after hip or knee replacement; Hip replacement - after - what to ask your doctor; Knee replacement - after - ...

  1. Hip or knee replacement - after - what to ask your doctor

    MedlinePlus

    ... PA: Elsevier Mosby; 2012:chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain ... joint replacement - discharge Taking care of your new hip joint Update Date 3/5/2015 Updated by: C. ...

  2. Hip or knee replacement - before - what to ask your doctor

    MedlinePlus

    ... PA: Elsevier Mosby; 2012:chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain ... joint replacement - discharge Taking care of your new hip joint Update Date 3/5/2015 Updated by: C. ...

  3. Joint Line Reconstruction in Navigated Total Knee Arthroplasty Revision

    ClinicalTrials.gov

    2012-05-16

    Revision Total Knee Arthroplasty Because of; Loosening; Instability; Impingement; or Other Reasons Accepted as Indications for TKA Exchange.; The Focus is to Determine the Precision of Joint Line Restoration in Navigated vs. Conventional Revision Total Knee Arthroplasty

  4. Techniques for assessing knee joint pain in arthritis

    PubMed Central

    Neugebauer, Volker; Han, Jeong S; Adwanikar, Hita; Fu, Yu; Ji, Guangchen

    2007-01-01

    The assessment of pain is of critical importance for mechanistic studies as well as for the validation of drug targets. This review will focus on knee joint pain associated with arthritis. Different animal models have been developed for the study of knee joint arthritis. Behavioral tests in animal models of knee joint arthritis typically measure knee joint pain rather indirectly. In recent years, however, progress has been made in the development of tests that actually evaluate the sensitivity of the knee joint in arthritis models. They include measurements of the knee extension angle struggle threshold, hind limb withdrawal reflex threshold of knee compression force, and vocalizations in response to stimulation of the knee. A discussion of pain assessment in humans with arthritis pain conditions concludes this review. PMID:17391515

  5. Corporate influences on epidemiology.

    PubMed

    Pearce, Neil

    2008-02-01

    Corporate influences on epidemiology have become stronger and more pervasive in the last few decades, particularly in the contentious fields of pharmacoepidemiology and occupational epidemiology. For every independent epidemiologist studying the side effects of medicines and the hazardous effects of industrial chemicals, there are several other epidemiologists hired by industry to attack the research and to debunk it as 'junk science'. In some instances these activities have gone as far as efforts to block publication. In many instances, academics have accepted industry funding which has not been acknowledged, and only the academic affiliations of the company-funded consultants have been listed. These activities are major threats to the integrity of the field, and its survival as a scientific discipline. There is no simple solution to these problems. However, for the last two decades there has been substantial discussion on ethics in epidemiology, partly in response to the unethical conduct of many industry-funded consultants. Professional organizations, such as the International Epidemiological Association, can play a major role in encouraging and supporting epidemiologists to assert positive principles of how science should work, and how it should be applied to public policy decisions, rather than simply having a list of what not to do. PMID:18245050

  6. Epidemiology of Down Syndrome

    ERIC Educational Resources Information Center

    Sherman, Stephanie L.; Allen, Emily G.; Bean, Lora H.; Freeman, Sallie B.

    2007-01-01

    Down syndrome (DS) is the most commonly identified genetic form of mental retardation and the leading cause of specific birth defects and medical conditions. Traditional epidemiological studies to determine the prevalence, cause, and clinical significance of the syndrome have been conducted over the last 100 years. DS has been estimated to occur…

  7. Phylogenetically resolving epidemiologic linkage

    PubMed Central

    Romero-Severson, Ethan O.; Bulla, Ingo; Leitner, Thomas

    2016-01-01

    Although the use of phylogenetic trees in epidemiological investigations has become commonplace, their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the true transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals’ HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. We confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results. PMID:26903617

  8. Phylogenetically resolving epidemiologic linkage

    DOE PAGESBeta

    Romero-Severson, Ethan O.; Bulla, Ingo; Leitner, Thomas

    2016-02-22

    The use of phylogenetic trees in epidemiological investigations has become commonplace, but their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the truemore » transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals’ HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. Moreover, we confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results.« less

  9. Epidemiology of Cardiovascular Diseases.

    ERIC Educational Resources Information Center

    Jenkins, C. David

    1988-01-01

    Reviews epidemiological studies of cardiovascular diseases especially coronary heart disease (CHD), to document their major public health importance, changes in mortality during this century, and international comparisons of trends. Finds major risk factors for CHD are determined in large part by psychosocial and behavioral mechanisms. Asserts…

  10. Phylogenetically resolving epidemiologic linkage.

    PubMed

    Romero-Severson, Ethan O; Bulla, Ingo; Leitner, Thomas

    2016-03-01

    Although the use of phylogenetic trees in epidemiological investigations has become commonplace, their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the true transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals' HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. We confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results. PMID:26903617

  11. Concepts in Huanglongbing Epidemiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Huanglongbing (HLB) was discovered in Brazil and Florida in 2004 and 2005 respectively. Previously, very few quantitative epidemiological studies had been conducted, and thus the increase and spread of the disease remains incompletely characterized. The perennial nature of the disease necessitates...

  12. Translational Epidemiology in Psychiatry

    PubMed Central

    Weissman, Myrna M.; Brown, Alan S.; Talati, Ardesheer

    2012-01-01

    Translational research generally refers to the application of knowledge generated by advances in basic sciences research translated into new approaches for diagnosis, prevention, and treatment of disease. This direction is called bench-to-bedside. Psychiatry has similarly emphasized the basic sciences as the starting point of translational research. This article introduces the term translational epidemiology for psychiatry research as a bidirectional concept in which the knowledge generated from the bedside or the population can also be translated to the benches of laboratory science. Epidemiologic studies are primarily observational but can generate representative samples, novel designs, and hypotheses that can be translated into more tractable experimental approaches in the clinical and basic sciences. This bedside-to-bench concept has not been explicated in psychiatry, although there are an increasing number of examples in the research literature. This article describes selected epidemiologic designs, providing examples and opportunities for translational research from community surveys and prospective, birth cohort, and family-based designs. Rapid developments in informatics, emphases on large sample collection for genetic and biomarker studies, and interest in personalized medicine—which requires information on relative and absolute risk factors—make this topic timely. The approach described has implications for providing fresh metaphors to communicate complex issues in interdisciplinary collaborations and for training in epidemiology and other sciences in psychiatry. PMID:21646577

  13. Comparative evaluation of single and bilayered lamotrigine floating tablets

    PubMed Central

    Lakshmi, PK; Sridhar, M; Shruthi, B

    2013-01-01

    Aim: The purpose of this study was to prepare lamotrigine (LM) bilayered and single layered floating tablets and to compare their release profiles. Materials and Methods: LM floating tablets were prepared by direct compression method. Drug, hydroxy propyl methyl cellulose K4M, lactose monohydrate and polyvinylpyrrolidone K30 constitute controlled release layer components and floating layer components includes polymers and sodium bicarbonate. The prepared tablets were evaluated for physicochemical parameters such as hardness, friability, weight variation, thickness, floating lag time (FLT), floating time, in vitro buoyancy study, in vitro release studies. The drug-polymer interaction was studied by fourier transform infrared and differential scanning calorimetry. Results and Discussion: The FLT of all the formulations were within the prescribed limits (<3 min). When ethyl cellulose was used as floating layer component, tablets showed good buoyancy effect but eroded within 6-8 h. Hence it was replaced with hydroxypropyl cellulose -M hydrophilic polymer, which showed good FLT and floating duration for 16 h. Formulation LFC4 was found to be optimized with dissolution profile of zero order kinetics showing fickian diffusion. A comparative study of bilayered and single layered tablets of LM showed a highest similarity factor of 83.03, difference factor of 2.74 and t-test (P < 0.05) indicates that there is no significant difference between them. Conclusion: Though bilayered tablet possess many advantages, single layered tablet would be economical, cost-effective and reproducible for large scale production in the industry. However, the results of present study demonstrated that the in vitro development of bilayered gastro retentive floating tablets with controlled drug release profile for LM is feasible. PMID:24167788

  14. Numerical simulation of melting ice around a floating by microwaves

    NASA Astrophysics Data System (ADS)

    Lakzian, Esmail; Parsian, Armin; Lakzian, Kazem

    2016-03-01

    In this paper a new method in using microwaves is provided for melting the ice around a floating equipment in a freezing condition in cold regions. The numerical simulation's results for validation are compared with the simple model's experimental data. Using microwave in melting the ice around a floating equipment is caused by lack of the mechanical wear, low energy dissipation factor and acceptable defrosting process speed in small lakes.

  15. Improved Automatically Locking/Unlocking Orthotic Knee Joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1995-01-01

    Proposed orthotic knee joint improved version of one described in "Automatically Locking/Unlocking Orthotic Knee Joint" (MFS-28633). Locks automatically upon initial application of radial force (wearer's weight) and unlocks automatically, but only when all loads (radial force and bending) relieved. Joints lock whenever wearer applies weight to knee at any joint angle between full extension and 45 degree bend. Both devices offer increased safety and convenience relative to conventional orthotic knee joints.

  16. Patients’ decision making in total knee arthroplasty

    PubMed Central

    Barlow, T.; Griffin, D.; Barlow, D.; Realpe, A.

    2015-01-01

    Objectives A patient-centred approach, usually achieved through shared decision making, has the potential to help improve decision making around knee arthroplasty surgery. However, such an approach requires an understanding of the factors involved in patient decision making. This review’s objective is to systematically examine the qualitative literature surrounding patients’ decision making in knee arthroplasty. Methods A systematic literature review using Medline and Embase was conducted to identify qualitative studies that examined patients’ decision making around knee arthroplasty. An aggregated account of what is known about patients’ decision making in knee arthroplasties is provided. Results Seven studies with 234 participants in interviews or focus groups are included. Ten themes are replicated across studies, namely: expectations of surgery; coping mechanisms; relationship with clinician; fear; pain; function; psychological implications; social network; previous experience of surgery; and conflict in opinions. Conclusions This review is helpful in not only directing future research to areas that are not understood, or require confirmation, but also in highlighting areas that future interventions could address. These include those aimed at delivering information, which are likely to affect the satisfaction rate, demand, and use of knee arthroplasties. Cite this article: Bone Joint Res 2015;4;163–169. PMID:26450640

  17. Cooling Does Not Affect Knee Proprioception

    PubMed Central

    Ozmun, John C.; Thieme, Heather A.; Ingersoll, Christopher D.; Knight, Kenneth L.

    1996-01-01

    The effect of cooling on proprioception of the knee has not been studied extensively. In this study, we investigated the movement reproduction (timing and accuracy) aspect of proprioception. Subjects were tested under two conditions: a 20-minute application of ice and control. Proprioceptive accuracy and timing were measured by passively moving the knee, then comparing the subject's active reproduction of the passive movement. Subjects were blindfolded, then tested in three sectors of the knee's range of motion: 90° to 60°, 60° to 30°, and 30° to full extension. Ice application had no apparent effect on the subject's ability to perform accurate movement reproductions in the sectors tested. However, accuracy of the subject's final angle reproduction varied between the sectors as did the total time of the movement. One possible explanation for the difference between sectors is that different receptors are active at different points in the knee's range of motion. We conclude that cooling the knee joint for 20 minutes does not have an adverse effect on proprioception. PMID:16558379

  18. Knee alignment in professional tennis players.

    PubMed

    Maquirriain, Javier

    2002-01-01

    This study determined lower-limb alignment and knee geometry in professional tennis players and compared the data with those from nonathletic individuals. Twenty-four radiographs from 12 asymptomatic players (mean age: 23.4+/-3.8 years) were prospectively studied. The three angles most useful for describing limb alignment and knee geometry in the coronal plane were measured: hip-knee-ankle, condylar-hip, and plateau-ankle. The condylar-plateau angle, frontal foot rotation angle, and the relationship between the mechanical axis and tibial plateau also were calculated. Varus limb alignment was predominant and the mechanical axis passed medially through the knee center; there was increased valgus inclination of the distal femur, varus angulation of the tibial plateau, near parallel alignment of the joint, and exaggerated external foot rotation. Hip-knee-ankle, condylar-hip, plateau-ankle, and frontal foot rotation angles were significantly different (P<.05, two-tailed t test) from previously reported angles of nonathletic individuals. Variations, probably due to repetitive dynamic demands imposed on lower limbs from an early age, seem to involve both femoral condyles and proximal tibial metaphyses, maintaining normal parallel joint alignment. PMID:11829331

  19. Arthrodiatasis for management of knee osteoarthritis.

    PubMed

    Aly, Tarek A; Hafez, Kamal; Amin, Osama

    2011-08-01

    Osteoarthritic disease is the result of mechanical and biological events that destabilize the normal processes of degradation and synthesis of articular cartilage chondrocytes, extracellular matrix, and subchondral bone. Osteoarthritis of the knee can cause symptoms ranging from mild to disabling. Initial management of most patients should be nonoperative, but because of the progressive nature of the disease, many patients with osteoarthritis of the knee eventually benefit from operative treatment. Various procedures have been described for treatment of the osteoarthritic knee, ranging from arthroscopic lavage and debridement to total knee arthroplasty. The aim of this study was to evaluate the clinical results of distraction arthroplasty combined with arthroscopic lavage and drilling of cartilage defects for treatment of osteoarthritis of the knee. Nineteen patients (15 women and 4 men; age range, 39-65 years) were operated on. Pre- and postoperative findings were compared. A control group comprising 42 patients treated with only arthroscopic procedures was evaluated for comparison. Follow-up ranged from 3 to 5 years. Results were evaluated both clinically and radiologically postoperatively and throughout the follow-up period. Clinically, pain and walking capacity improved in most patients. Radiologically, joint space widening and improvement of the tibiofemoral angle was noted in nearly all patients. PMID:21815573

  20. The Difficult Primary Total Knee Arthroplasty.

    PubMed

    Malkani, Arthur L; Hitt, Kirby D; Badarudeen, Sameer; Lewis, Courtland; Cherian, Jeffrey; Elmallah, Randa; Mont, Michael A

    2016-01-01

    Primary total knee arthroplasty (TKA) for the treatment of knee arthritis has substantially increased over the past decade. Because of its success, the indications for primary TKA have expanded to include younger patients who are more active, elderly patients who have multiple comorbidities, and patients who have more complex issues, such as posttraumatic arthritis and severe deformity. TKA also has been used to salvage failed unicondylar arthroplasty and osteotomies about the knee. Exposure may be challenging and outcomes may not be as successful in patients with soft-tissue contractures, such as a stiff knee, who undergo TKA. Bone graft or augments may be required to correct deformity and attain proper knee alignment in patients who have a substantial varus or valgus deformity. TKA is somewhat challenging in patients who have deformity, bone loss, contracture, or multiple comorbidities, or have had prior surgery; therefore, it is necessary for surgeons to be aware of some general principles that may help minimize complications and improve outcomes. PMID:27049194

  1. An Analysis of the Full-Floating Journal Bearing

    NASA Technical Reports Server (NTRS)

    Shaw, M.C.; Nussdorfer, T.J.

    1947-01-01

    An analysis of the operating characteristics of a full-floating bearing - a bearing in which a floating sleeve is located between the journal and bearing surfaces - is presented together with charts - from which the performance of such bearings may be predicted. Examples are presented to illustrate the use of these charts and a limited number of experiments conducted upon a glass full-floating bearing to verify some results of the analysis are reported. The floating sleeve can operate over a wide range of speeds for a given shaft speed, the exact value depending principally upon the ratio of clearances and upon the ratio of radii of the bearing. Lower operating temperatures at high rotative speeds are to be expected by using a full-floating bearing. This lower operating temperature would be obtained at the expense of the load-carrying capacity of the bearing if, for comparison, the clearances remain the same in both bearings. A full-floating bearing having the same load capacity as a conventional journal bearing may be designed if decreased clearances are allowable.

  2. Fuel primer for float type carburetors

    SciTech Connect

    Scott, W.A.

    1988-04-19

    A fuel primer for float type carburetors having a fuel bowl, the fuel bowl coupled with a fuel inlet, an outlet vent, and a nozzle, the fuel inlet coupled with a fuel source and the nozzle coupled with an intake path, the primer is described comprising: means coupled with the outlet for introducing a pressurized fluid flow in the fuel bowl and means associated with the fuel bowl and ambient air for automatically enabling ambient air flow to enter into the fuel bowl upon start up and for enabling fuel flow to enter into the intake path from the fuel bowl during pressurization of the fluid while preventing the fuel flow from exiting the air flow means during pressurization of the fluid such that air enters an engine through the means associated with the fuel bowl and the engine begins to run and continues to run during start up enabling an operator to move a choke from a closed to an open position for continuous operation of the engine.

  3. Multilateral installation from a floating rig

    SciTech Connect

    1998-07-01

    The Troll Olje gas province is approximately 100 km northwest of Bergen, Norway, in the Norwegian sector of the North Sea at a water depth of approximately 315 to 340 m. Troll Olje is part of the Troll gas field, where Norsk Hydro is responsible for developing two areas with thin oil rims. Before spudding the multilateral well described in this paper, 17 wells had been drilled and completed in the Troll Olje oil province. The multilateral-well concept was introduced in the gas province primarily to increase the drainage area for each well. When producing from two separate laterals, a lower drawdown pressure exists throughout the horizontal section. Therefore, gas coning is less likely to occur, and higher production rates can be sustained for a longer period of time. In addition, cost savings are substantial because of reduced well-construction time for each horizontal reservoir-drainage section and because of the reduced number of completion strings, subsea wellheads, and pipelines required for total field development. The full-length paper details design, development, testing, and installation of the first successful multilateral well installed from a floating rig offshore Norway. The paper gives a synopsis.

  4. Traumatic Floating Clavicle- A case report

    PubMed Central

    Sopu, Alexandra; Green, Connor; Molony, Diarmuid

    2015-01-01

    Introduction: Shoulder injuries after high velocity trauma are common. Clavicle is affected in almost half of these cases. Even so, bipolar dislocation of the clavicle is an unusual injury and seldom reported in the literature. Conservative management is used for almost all the cases and only selected cases will undergo surgical treatment. Case Report: A 52 year old right electrician presented to the emergency department following a fall from a push bicycle. Plain radiographs identified a left first metacarpal (MC) fracture and a bipolar fracture of his right clavicle. Following Fracture Clinic review, significant deformity of the medial clavicle was noted and a CT scan showed anterior dislocation of the medial fragment. Given the degree of deformity and this functional requirement we felt that operative treatment was most appropriate for his unstable medial clavicle fracture dislocation. Conclusion: Surgical treatment of floating clavicle has an important role in the management of fit and active patients. It is important to identify the mechanism of injury and deforming forces in fractures and only after this to plan to neutralise these where appropriate. PMID:27299032

  5. Abnormal loading of the major joints in knee osteoarthritis and the response to knee replacement.

    PubMed

    Metcalfe, Andrew; Stewart, Caroline; Postans, Neil; Barlow, David; Dodds, Alexander; Holt, Cathy; Whatling, Gemma; Roberts, Andrew

    2013-01-01

    Knee osteoarthritis is common and patients frequently complain that they are 'overloading' the joints of the opposite leg when they walk. However, it is unknown whether moments or co-contractions are abnormal in the unaffected joints of patients with single joint knee osteoarthritis, or how they change following treatment of the affected knee. Twenty patients with single joint medial compartment knee osteoarthritis were compared to 20 asymptomatic control subjects. Gait analysis was performed for normal level gait and surface EMG recordings of the medial and lateral quadriceps and hamstrings were used to investigate co-contraction. Patients were followed up 12 months post-operatively and the analysis was repeated. Results are presented for the first 14 patients who have attended follow-up. Pre-operatively, adduction moment impulses were elevated at both knees and the contra-lateral hip compared to controls. Co-contraction of hamstrings and quadriceps was elevated bilaterally. Post-operatively, moment waveforms returned to near-normal levels at the affected knee and co-contraction fell in the majority of patients. However, abnormalities persisted in the contra-lateral limb with partial or no recovery of both moment waveforms and co-contraction in the majority. Patients with knee osteoarthritis do experience abnormal loads of their major weight bearing joints bilaterally, and abnormalities persist despite treatment of the affected limb. Further treatment may be required if we are to protect the other major joints following joint arthroplasty. PMID:22841587

  6. Variable stiffness actuated prosthetic knee to restore knee buckling during stance: a modeling study.

    PubMed

    Wentink, E C; Koopman, H F J M; Stramigioli, S; Rietman, J S; Veltink, P H

    2013-06-01

    Most modern intelligent knee prosthesis use dampers to modulate dynamic behavior and prevent excessive knee flexion, but they dissipate energy and do not assist in knee extension. Energy efficient variable stiffness control (VSA) can reduce the energy consumption yet effectively modulate the dynamic behavior and use stored energy during flexion to assist in subsequent extension. A principle design of energy efficient VSA in a prosthetic knee is proposed and analyzed for the specific case of rejection of a disturbed stance phase. The concept is based on the principle that the output stiffness of a spring can be changed without changing the energy stored in the elastic elements of the spring. The usability of this concept to control a prosthetic knee is evaluated using a model. Part of the stance phase of the human leg was modeled by a double pendulum. Specifically the rejection of a common disturbance of transfemoral prosthetic gait, an unlocked knee at heel strike, was evaluated. The ranges of spring stiffnesses were determined such that the angular characteristics of a normal stance phase were preserved, but disturbances could also be rejected. The simulations predicted that energy efficient VSA can be useful for the control of prosthetic knees. PMID:23000012

  7. Users of oestrogen replacement therapy have more knee cartilage than non-users

    PubMed Central

    Wluka, A; Davis, S; Bailey, M; Stuckey, S; Cicuttini, F

    2001-01-01

    BACKGROUND—Osteoarthritis (OA) is increasingly prevalent in the years after menopause. Epidemiological data suggest that the use of oestrogen replacement therapy (ERT) may protect against knee OA.
AIM—To test the hypothesis that long term ERT (longer than five years) is associated with increased knee cartilage in postmenopausal women.
METHODS—The study involved 81 women (42 current users (⩾ five years) of ERT and 39 who had never used it). Articular cartilage volumes were determined by processing images acquired in the sagittal plane using a T1 weighted fat suppressed magnetic resonance sequence on an independent work station.
RESULTS—After bone size had been accounted for, ERT users had higher tibial cartilage volume than non-users. Total tibial cartilage volume was 7.7% (0.23 ml) greater in the group of ERT users (2.98 (0.47) ml; mean (SD)) than in the untreated group (2.75 (0.50) ml). The difference, after adjustment for the significant explanatory factors (years since menopause, body mass index, age at menopause, and smoking), between the ERT users and non-users increased from 0.23 ml to 0.30 ml (95% confidence interval 0.08 to 0.52, p=0.008). These differences persisted after exclusion of women with OA.
CONCLUSIONS—After adjustment for multiple confounders, women using long term ERT have more knee cartilage than controls. This may indicate that ERT prevents loss of knee articular cartilage.

 PMID:11247861

  8. MR imaging of extrasynovial inflammation and impingement about the knee.

    PubMed

    Grando, Higor; Chang, Eric Y; Chen, Karen C; Chung, Christine B

    2014-11-01

    The knee has unique anatomy regarding the relationship between the synovial and capsular layers, with interposed fat pads at certain locations. The extrasynovial impingement and inflammation syndromes about the knee are underdiagnosed and should be included in the differential diagnosis of anterior knee pain. MR imaging is the best imaging modality for evaluation of the anatomy and disorders of these extrasynovial compartments. PMID:25442030

  9. Lateral Knee Braces in Football: Do They Prevent Injury?

    ERIC Educational Resources Information Center

    Paulos, Lonnie E.; And Others

    1986-01-01

    The results of three recently presented clinical studies and a biomechanical study of the use of lateral knee braces to prevent knee injuries are reviewed. The results raise serious doubts about the efficacy of the preventive knee braces which are currently available. (Author/MT)

  10. Evaluation of total knee mechanics using a crouching simulator with a synthetic knee substitute.

    PubMed

    Lowry, Michael; Rosenbaum, Heather; Walker, Peter S

    2016-05-01

    Mechanical evaluation of total knees is frequently required for aspects such as wear, strength, kinematics, contact areas, and force transmission. In order to carry out such tests, we developed a crouching simulator, based on the Oxford-type machine, with novel features including a synthetic knee including ligaments. The instrumentation and data processing methods enabled the determination of contact area locations and interface forces and moments, for a full flexion-extension cycle. To demonstrate the use of the simulator, we carried out a comparison of two different total knee designs, cruciate retaining and substituting. The first part of the study describes the simulator design and the methodology for testing the knees without requiring cadaveric knee specimens. The degrees of freedom of the anatomic hip and ankle joints were reproduced. Flexion-extension was obtained by changing quadriceps length, while variable hamstring forces were applied using springs. The knee joint was represented by three-dimensional printed blocks on to which the total knee components were fixed. Pretensioned elastomeric bands of realistic stiffnesses passed through holes in the block at anatomical locations to represent ligaments. Motion capture of the knees during flexion, together with laser scanning and computer modeling, was used to reconstruct contact areas on the bearing surfaces. A method was also developed for measuring tibial component interface forces and moments as a comparative assessment of fixation. The method involved interposing Tekscan pads at locations on the interface. Overall, the crouching machine and the methodology could be used for many different mechanical measurements of total knee designs, adapted especially for comparative or parametric studies. PMID:26802075

  11. Robotic control in knee joint replacement surgery.

    PubMed

    Davies, B L; Rodriguez y Baena, F M; Barrett, A R W; Gomes, M P S F; Harris, S J; Jakopec, M; Cobb, J P

    2007-01-01

    A brief history of robotic systems in knee arthroplasty is provided. The place of autonomous robots is then discussed and compared to more recent 'hands-on' robotic systems that can be more cost effective. The case is made for robotic systems to have a clear justification, with improved benefits compared to those from cheaper navigation systems. A number of more recent, smaller, robot systems for knee arthroplasty are also described. A specific example is given of an active constraint medical robot, the ACROBOT system, used in a prospective randomized controlled trial of unicondylar robotic knee arthroplasty in which the robot was compared to conventional surgery. The results of the trial are presented together with a discussion of the need for measures of accuracy to be introduced so that the efficacy of the robotic surgery can be immediately identified, rather than have to wait for a number of years before long-term clinical improvements can be demonstrated. PMID:17315770

  12. The Basic Science of Human Knee Menisci

    PubMed Central

    Fox, Alice J. S.; Bedi, Asheesh; Rodeo, Scott A.

    2012-01-01

    Context: Information regarding the structure, composition, and function of the knee menisci has been scattered across multiple sources and fields. This review contains a concise, detailed description of the knee menisci—including anatomy, etymology, phylogeny, ultrastructure and biochemistry, vascular anatomy and neuroanatomy, biomechanical function, maturation and aging, and imaging modalities. Evidence Acquisition: A literature search was performed by a review of PubMed and OVID articles published from 1858 to 2011. Results: This study highlights the structural, compositional, and functional characteristics of the menisci, which may be relevant to clinical presentations, diagnosis, and surgical repairs. Conclusions: An understanding of the normal anatomy and biomechanics of the menisci is a necessary prerequisite to understanding the pathogenesis of disorders involving the knee. PMID:23016106

  13. Functional knee assessment with advanced imaging.

    PubMed

    Amano, Keiko; Li, Qi; Ma, C Benjamin

    2016-06-01

    The purpose of anterior cruciate ligament (ACL) reconstruction is to restore the native stability of the knee joint and to prevent further injury to meniscus and cartilage, yet studies have suggested that joint laxity remains prevalent in varying degrees after ACL reconstruction. Imaging can provide measurements of translational and rotational motions of the tibiofemoral joint that may be too small to detect in routine physical examinations. Various imaging modalities, including fluoroscopy, computed tomography (CT), and magnetic resonance imaging (MRI), have emerged as powerful methods in measuring the minute details involved in joint biomechanics. While each technique has its own strengths and limitations, they have all enhanced our understanding of the knee joint under various stresses and movements. Acquiring the knowledge of the complex and dynamic motions of the knee after surgery would help lead to improved surgical techniques and better patient outcomes. PMID:27052009

  14. Knee osteoarthritis: a review of management options.

    PubMed

    Hussain, S M; Neilly, D W; Baliga, S; Patil, S; Meek, Rmd

    2016-02-01

    Osteoarthritis of the knee is a complex peripheral joint disorder with multiple risk factors. The molecular basis of osteoarthritis has been generally accepted; however, the exact pathogenesis is still not known. Management of patients with osteoarthritis involves a comprehensive history, thorough physical examination and appropriate radiological investigation. The relative slow progress in the disease allows a stepwise algorithmic approach in treatment. Non-surgical treatment involves patient education, lifestyle modification and the use of orthotic devises. These can be achieved in the community. Surgical options include joint sparing procedures such as arthroscopyando osteotomy or joint-replacing procedures. Joint-replacing procedures can be isolated to a single compartment such as patellofemoral arthroplasty or unicompartmental knee replacement or total knee arthroplasty. The key to a successful long-term outcome is optimal patient selection, preoperative counselling and good surgical technique. PMID:27330013

  15. Knee instability scores for ACL reconstruction.

    PubMed

    Rahnemai-Azar, Ata A; Naendrup, Jan-Hendrik; Soni, Ashish; Olsen, Adam; Zlotnicki, Jason; Musahl, Volker

    2016-06-01

    Despite abundant biological, biomechanical, and clinical research, return to sport after anterior cruciate ligament (ACL) injury remains a significant challenge. Residual rotatory knee laxity has been identified as one of the factors responsible for poor functional outcome. To improve and standardize the assessment of knee instability, a variety of instability scoring systems is available. Recently, devices to objectively quantify static and dynamic clinical exams have been developed to complement traditional subjective grading systems. These devices enable an improved evaluation of knee instability and possible associated injuries. This additional information may promote the development of new treatment algorithms and allow for individualized treatment. In this review, the different subjective laxity scores as well as complementary objective measuring systems are discussed, along with an introduction of injury to an individualized treatment algorithm. PMID:26980119

  16. Major vascular injuries complicating knee arthroscopy

    PubMed Central

    Bancu, Serban; Muresan, Mircea; Sala, Daniela

    2015-01-01

    Starting with a case report, we made a detailed review of the literature, with the purpose of identifying and analyzing the type of iatrogenic vascular lesion following knee arthroscopy and the method of vascular repair. A PubMed literature search was undertaken to locate all reported cases of major vascular iatrogenic injuries during arthroscopic knee procedures. We identified 39 papers which report a total of 62 cases of major iatrogenic popliteal lesions after knee arthroscopy, between 1985 and 2014. The type of arthroscopic intervention performed, the type of iatrogenic vascular lesion encountered, the time passed until its discovery and treatment, the method of vascular reconstruction, and the postoperative course are presented. Postarthroscopy vascular complications are infrequent but potentially disastrous for the condition of the affected inferior limb. An early diagnosis and reintervention are mandatory for a good postoperative outcome. PMID:26240627

  17. Knee Pain in Children: Part I: Evaluation.

    PubMed

    Wolf, Michael

    2016-01-01

    • On the basis of primarily consensus, due to lack of relevant clinical studies, the information obtained from the history and physical examination is the key to establishing a diagnosis and directing initial management of knee pain. • By applying history and physical examination findings to a diagnosis and management algorithm, clinicians can efficiently and effectively determine the potential cause of the knee pain. • On the basis of primarily consensus, due to lack of relevant clinical studies, the most important step of the evaluation of knee pain is to identify emergent conditions, including limb- and life-threatening conditions (eg, septic arthritis, osteomyelitis, and malignancy), hip pathology, or conditions associated with effusions. PMID:26729778

  18. Influence of different types of low substituted hydroxypropyl cellulose on tableting, disintegration, and floating behaviour of floating drug delivery systems

    PubMed Central

    Diós, Péter; Pernecker, Tivadar; Nagy, Sándor; Pál, Szilárd; Dévay, Attila

    2014-01-01

    The object of the present study is to evaluate the effect of application of low-substituted hydroxypropyl cellulose (L-HPC) 11 and B1 as excipients promoting floating in gastroretentive tablets. Directly compressed tablets were formed based on experimental design. Face-centred central composite design was applied with two factors and 3 levels, where amount of sodium alginate (X1) and L-HPC (X2) were the numerical factors. Applied types of L-HPCs and their 1:1 mixture were included in a categorical factor (X3). Studied parameters were floating lag time, floating time, floating force, swelling behaviour of tablets and dissolution of paracetamol, which was used as a model active substance. Due to their physical character, L-HPCs had different water uptake and flowability. Lower flowability and lower water uptake was observed after 60 min at L-HPC 11 compared to L-HPC B1. Shorter floating times were detected at L-HPC 11 and L-HPC mixtures with 0.5% content of sodium alginate, whereas alginate was the only significant factor. Evaluating results of drug release and swelling studies on floating tablets revealed correlation, which can serve to help to understand the mechanism of action of L-HPCs in the field development of gastroretentive dosage forms. PMID:26702261

  19. Correcting deformity in total knee arthroplasty: Techniques to avoid the release of collateral ligaments in severely deformed knees.

    PubMed

    Mullaji, A B; Shetty, G M

    2016-01-01

    Collateral ligament release is advocated in total knee arthroplasty (TKA) to deal with significant coronal plane deformities, but is also associated with significant disadvantages. We describe steps to avoid release of the collateral (superficial medial and lateral collateral) ligaments during TKA in severely deformed knees, while correcting deformity and balancing the knee. PMID:26733653

  20. Total knee replacement with and without patellar resurfacing: a prospective, randomised trial using the profix total knee system.

    PubMed

    Smith, A J; Wood, D J; Li, M-G

    2008-01-01

    We have examined the differences in clinical outcome of total knee replacement (TKR) with and without patellar resurfacing in a prospective, randomised study of 181 osteoarthritic knees in 142 patients using the Profix total knee system which has a femoral component with features considered to be anatomical and a domed patellar implant. The procedures were carried out between February 1998 and November 2002. A total of 159 TKRs in 142 patients were available for review at a mean of four years (3 to 7). The patients and the clinical evaluator were blinded in this prospective study. Evaluation was undertaken annually by an independent observer using the knee pain scale and the Knee Society clinical rating system. Specific evaluation of anterior knee pain, stair-climbing and rising from a seated to a standing position was also undertaken. No benefit was shown of TKR with patellar resurfacing over that without resurfacing with respect to any of the measured outcomes. In 22 of 73 knees (30.1%) with and 18 of 86 knees (20.9%) without patellar resurfacing there was some degree of anterior knee pain (p = 0.183). No revisions related to the patellofemoral joint were performed in either group. Only one TKR in each group underwent a re-operation related to the patellofemoral joint. A significant association between knee flexion contracture and anterior knee pain was observed in those knees with patellar resurfacing (p = 0.006). PMID:18160498

  1. Introduction of total knee arthroplasty in Lithuania

    PubMed Central

    Stucinskas, Justinas; Robertsson, Otto; Wingstrand, Hans

    2009-01-01

    Background and purpose We have previously reported that the first 10 years of hip arthroplasty in Lithuania resulted in a higher cumulative revision rate than that observed in Sweden. We thus compared the corresponding results after introduaction of total knee replacement in Lithuania. Methods The 10-year revision rate for the first 595 primary ScanKnee arthroplasties inserted in Klaipeda, Lithuania, was compared to that for the first 1,280 ScanKnee primary arthroplasties inserted in Sweden. As in the hip replacement study, only patients with osteoarthritis (OA) were included. Primary knee arthroplasties without patellar resurfacing were included, and the endpoint was revision for any reason other than addition of a patellar component. Results We found that the cumulative revision rate was not statistically significantly different between the groups. The revision pattern was different, however, and we observed 24 isolated patellar component additions in Sweden, but none in Klaipeda. Interpretation Contrary to the results of our previous hip arthroplasty study, the cumulative revision rate after total knee arthroplasty was similar in the two groups. This suggests that compared to hip arthroplasty, the outcome of total knee arthroplasty was less dependent on surgical experience. The large difference regarding isolated patellar component additions may be explained by long-term accumulation of severe OA cases in Lithuania. To patients subject to a newly introduced surgical treatment offering great improvement in quality of life, patellofemoral pain may be a minor problem. Furthermore, patellar problems may not have seemed particularly relevant for the surgeons, considering the disability of other patients waiting to be treated. PMID:19297790

  2. Gait Using Pneumatic Brace for End-Stage Knee Osteoarthritis.

    PubMed

    Kapadia, Bhaveen H; Cherian, Jeffrey Jai; Starr, Roland; Chughtai, Morad; Mont, Michael A; Harwin, Steven F; Bhave, Anil

    2016-04-01

    More than 20 million individuals in the United States are affected by knee osteoarthritis (OA), which can lead to altered biomechanics and excessive joint loading. The use of an unloader pneumatic brace with extension assist has been proposed as a nonoperative treatment modality that may improve gait mechanics and correct knee malalignment. We assessed the following parameters in patients who have knee OA treated with and without a brace: (1) changes in temporospatial parameters in gait; (2) knee range of motion, knee extension at heel strike, and foot placement; (3) knee joint moments and impulse; and (4) changes in dynamic stiffness and rate of change of knee flexion during midstance to terminal stance. This 2:1 prospective, randomized, single-blinded trial evaluated 36 patients (24 brace and 12 matching). OA knee patients were randomized to receive either a pneumatic unloader brace or a standard nonoperative treatment regimen as the matching cohort for a 3-month period. They underwent evaluation of gait parameters using a three-dimensional gait analysis system at their initial appointment and at 3 months follow-up. All the testing, pre- and postbracing were performed without wearing the brace to examine for retained effects. Treatment with the brace led to significant improvements versus standard treatment in various gait parameters. Patients in the brace group had improvements in walking speed, knee extension at heel strike, total range of motion, knee joint forces, and rate of knee flexion from midstance to terminal stance when compared with the matching cohort. Knee OA patients who used a pneumatic unloader brace for 3 months for at least 3 hours per day had significant improvements various gait parameters when compared with a standard nonoperative therapy cohort. Braced patients demonstrated gait-modifying affects when not wearing the brace. These results are encouraging and suggest that this device represents a promising treatment modality for knee OA that

  3. Kinematic Analysis of a Posterior-stabilized Knee Prosthesis

    PubMed Central

    Zhao, Zhi-Xin; Wen, Liang; Qu, Tie-Bing; Hou, Li-Li; Xiang, Dong; Bin, Jia

    2015-01-01

    Background: The goal of total knee arthroplasty (TKA) is to restore knee kinematics. Knee prosthesis design plays a very important role in successful restoration. Here, kinematics models of normal and prosthetic knees were created and validated using previously published data. Methods: Computed tomography and magnetic resonance imaging scans of a healthy, anticorrosive female cadaver were used to establish a model of the entire lower limbs, including the femur, tibia, patella, fibula, distal femur cartilage, and medial and lateral menisci, as well as the anterior cruciate, posterior cruciate, medial collateral, and lateral collateral ligaments. The data from the three-dimensional models of the normal knee joint and a posterior-stabilized (PS) knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis, which was then validated by comparison with a previous study. The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0–135° flexion. Results: Both the output data trends and the measured values derived from the normal knee's kinematics model were very close to the results reported in a previous in vivo study, suggesting that this model can be used for further analyses. The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient, or insufficiently aggressive, “rollback” compared with the lateral femur of the normal knee. In addition, a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis. Conclusions: There were still several differences between the kinematics of the PS knee prosthesis and a normal knee, suggesting room for improving the design of the PS knee prosthesis. The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis. PMID:25591565

  4. Moxibustion Treatment for Knee Osteoarthritis

    PubMed Central

    Li, Ang; Wei, Zhi-Jian; Liu, Yi; Li, Bo; Guo, Xing; Feng, Shi-Qing

    2016-01-01

    Abstract To determine whether the administration of moxibustion is an effective treatment for knee osteoarthritis (KOA). We conducted a search of relevant articles using Medline, EMBASE, the Web of Science, and the Cochrane Library published before October 2015. The Western Ontario and McMaster Universities’ Osteoarthritis Index (WOMAC scale) and the short form 36 questionnaire (SF-36 scale) were assessed. Evidence grading was evaluated according to the Grading of Recommendations, Assessment, Development and Evaluation system. Four studies containing 746 participants fulfilled the inclusion criteria in the final analysis. In terms of quality of life (QOL), the meta-analysis of 2 randomized clinical trials (RCTs) showed significantly effects of moxibustion only in bodily pain (BP) compared with those in the control group (n = 348; weighted mean difference [WMD], 4.36; 95% confidence intervals [CIs], 2.27–6.44; P < 0.0001; heterogeneity: χ2 = 1.53, P = 0.22, I2 = 34%) in all of the subcategories of the SF-36 scale, with moderate quality. The meta-analysis of the 2 included trials showed that there was not a statistically significant difference in the pain or function subscale for the WOMAC scale when the 2 groups were compared (n = 322; WMD, 17.63; 95% CI, −23.15–58.41; P = 0.40; heterogeneity: χ2 = 19.42, P < 0.0001, I2 = 95%), with low or moderate quality separately. The administration of moxibustion can to some extent alleviate the symptoms of KOA. More rigorous, randomized controlled trials are required in the future. PMID:27057863

  5. Tibial rotation kinematics subsequent to knee arthroplasty

    PubMed Central

    Collins, Duane J.; Khatib, Yasser H.; Parker, David A.; Jenkin, Deanne E.; Molnar, Robert B.

    2015-01-01

    Background The use of computer assisted joint replacement has facilitated precise intraoperative measurement of knee kinematics. The changes in “screw home mechanism” (SHM) resulting from Total Knee Arthroplasty (TKA) with different prostheses and constraints has not yet been accurately described. Methods A pilot study was first completed. Intraoperative kinematic data was collected two groups of 15 patients receiving different prostheses. Results On average, patients lost 5.3° of ER (SD = 6.1°). There was no significant difference between the prostheses or different prosthetic constraints. Conclusions There significant loss of SHM after TKA. Further research is required to understand its impact on patient function. PMID:25829754

  6. Soft tissue balancing in total knee arthroplasty

    PubMed Central

    MELONI, MARIA CHIARA; HOEDEMAEKER, RUSSALKA W.; VIOLANTE, BRUNO; MAZZOLA, CLAUDIO

    2014-01-01

    A good outcome in total knee arthroplasty depends on many factors: joint alignment, range of motion, patellar tracking and ligament stability. A correct soft tissue balance keeps the joint aligned in flexion and extension, and therefore constitutes the most important factor for durability of the implant. Indeed, incorrect soft tissue balancing is the primary cause of early implant failure necessitating revision surgery. Soft tissue releases, serving to correct imbalances, are performed until the flexion and extension gaps appear symmetrical and balanced. A knee is considered perfectly balanced when the flexion and extension gaps are perfectly rectangular and all the measurements are absolutely equal. PMID:25606540

  7. Safety of knee radiosynovectomy with yttrium - 90

    NASA Astrophysics Data System (ADS)

    Kempińska, M.; Lass, P.; Ćwikła, J. B.; Żbikowski, P.

    2011-09-01

    Radioisotope knee synovectomy is based on an Yttrium - 90 citrate injection (185 - 222 MBq) into the knee joint cavity. The performance of procedure needs participation of a nuclear medicine specialist as well as an orthopedist or a rheumatologist and a technologist, who prepares radiopharmaceuticals. The ionization doses for patients and personnel depend not only on the injected activity, but also on the method and process of injection and the radioactivity measurement procedure used. The aim of this study is the evaluation of the degree of radiation exposure of patients and medical personnel during the performance of therapy with 90Y.

  8. Snapping Pes Syndrome after Unicompartmental Knee Arthroplasty

    PubMed Central

    Taketomi, Shuji; Yamagami, Ryota; Tahara, Keitaro; Tanaka, Sakae

    2016-01-01

    Snapping pes syndrome is defined as a snapping sensation in the medial knee caused by pes anserinus and rarely occurs. Snapping pes syndrome after unicompartmental knee arthroplasty (UKA) has not been reported yet. We experienced two cases with this syndrome after UKA. Conservative treatment was effective in one case, while surgical excision of the gracilis tendon was necessary to relieve painful snapping in the other case. The main cause of the first case might be posteromedial overhang of the tibial tray that reached up to 5 mm. The probable cause of the second case was posteromedial overhang of the mobile bearing. PMID:27274476

  9. Anterolateral rotatory instability of the knee.

    PubMed

    Guenther, Daniel; Griffith, Chad; Lesniak, Bryson; Lopomo, Nicola; Grassi, Alberto; Zaffagnini, Stefano; Fu, Freddie H; Musahl, Volker

    2015-10-01

    Recent publications have generated renewed interest in the anatomy of the anterolateral capsule. Knowledge of the biomechanical function of the anterolateral components is lacking. Further research is required to evaluate the influence of the anterolateral capsule on rotatory laxity of the knee. The role of surgical procedures, such as an extra-articular tenodesis or lateral plasty, has to be defined based on quantification of the injury. This article seeks to summarize the current literature and discusses the role of the anterolateral capsule and reconstructive techniques in combined ligamentous knee trauma. Level of evidence V. PMID:25941044

  10. [Epidemiology of osteoporosis].

    PubMed

    Scheidt-Nave, C; Ziegler, R; Raspe, H

    1998-03-15

    Epidemiological studies have identified osteoporosis as a disease of significant public health impact and have delineated numerous potential risk factors. Nevertheless, it has proven difficult to establish preventive strategies for several reasons. First, there has been no final agreement on the definition of osteoporosis, which has hampered efforts to characterize the magnitude of the problem as a whole. Secondly, as osteoporosis is a multifactorial chronic disorder, effective programs for risk assessment and intervention depend on the development of complex disease models. In summarizing the contributions of epidemiological studies to the current understanding of osteoporosis this review intends to outline the scientific background for the European Vertebral Osteoporosis Study (EVOS) and its successors. PMID:9564151

  11. [Rickettsioses: the epidemiological assessment].

    PubMed

    Lukin, E P; Makhlaĭ, A A; Perepelkin, V S

    1997-08-01

    Microbe of taxonomical families Rickettsiaceae aceal and Bartonellaceae of Rickettsiales order have caused not less than 14 nosological forms of disease among people in different parts of the world. About 8 of them--in Russia and in the former Soviet Republics. These diseases are not unequivocal from epidemiological point of view. Trench, Marseilles and other forms of fever, murine typhus, vesicules rickettsia, etc. have been liquidated and never recurred for 30-40 years. Prowazek's [correction of Provachek's] rickettsia in its two forms has lost its epidemiological meaning in Russia and is next to full disappearance. However, some types of fever still represent a definite threat to public health. Some diseases, like ehrlichiosis, Bartonella, tsutsugamushi fever have not yet been studied to the end in Russia. PMID:9424811

  12. Prospects for Epigenetic Epidemiology

    PubMed Central

    Foley, Debra L.; Craig, Jeffrey M.; Morley, Ruth; Olsson, Craig J.; Dwyer, Terence; Smith, Katherine

    2009-01-01

    Epigenetic modification can mediate environmental influences on gene expression and can modulate the disease risk associated with genetic variation. Epigenetic analysis therefore holds substantial promise for identifying mechanisms through which genetic and environmental factors jointly contribute to disease risk. The spatial and temporal variance in epigenetic profile is of particular relevance for developmental epidemiology and the study of aging, including the variable age at onset for many common diseases. This review serves as a general introduction to the topic by describing epigenetic mechanisms, with a focus on DNA methylation; genetic and environmental factors that influence DNA methylation; epigenetic influences on development, aging, and disease; and current methodology for measuring epigenetic profile. Methodological considerations for epidemiologic studies that seek to include epigenetic analysis are also discussed. PMID:19139055

  13. Unexpected wear of an unicompartimental knee arthroplasty in oxidized zirconium.

    PubMed

    Luyet, Anais; Fischer, Jean-François; Jolles, Brigitte M; Lunebourg, Alexandre

    2015-12-01

    Unicompartimental knee arthroplasty is a successful procedure for the treatment of localized osteoarthritis to one compartment of the knee with good long-term results. However, several modes of failure of unicompartimental knee arthroplasty have been described, namely aseptic or septic loosening, progression of disease, wear, and instability. Metallosis after unicompartimental knee arthroplasty is rarely reported and is most often related with polyethylene wear or break. We report on a case of rapid failure of unicompartimental knee arthroplasty in oxidized zirconium associated with metallosis secondary to the dislocation of the polyethylene. PMID:26790806

  14. Design of a reversible single precision floating point subtractor.

    PubMed

    Anantha Lakshmi, Av; Sudha, Gf

    2014-01-01

    In recent years, Reversible logic has emerged as a major area of research due to its ability to reduce the power dissipation which is the main requirement in the low power digital circuit design. It has wide applications like low power CMOS design, Nano-technology, Digital signal processing, Communication, DNA computing and Optical computing. Floating-point operations are needed very frequently in nearly all computing disciplines, and studies have shown floating-point addition/subtraction to be the most used floating-point operation. However, few designs exist on efficient reversible BCD subtractors but no work on reversible floating point subtractor. In this paper, it is proposed to present an efficient reversible single precision floating-point subtractor. The proposed design requires reversible designs of an 8-bit and a 24-bit comparator unit, an 8-bit and a 24-bit subtractor, and a normalization unit. For normalization, a 24-bit Reversible Leading Zero Detector and a 24-bit reversible shift register is implemented to shift the mantissas. To realize a reversible 1-bit comparator, in this paper, two new 3x3 reversible gates are proposed The proposed reversible 1-bit comparator is better and optimized in terms of the number of reversible gates used, the number of transistor count and the number of garbage outputs. The proposed work is analysed in terms of number of reversible gates, garbage outputs, constant inputs and quantum costs. Using these modules, an efficient design of a reversible single precision floating point subtractor is proposed. Proposed circuits have been simulated using Modelsim and synthesized using Xilinx Virtex5vlx30tff665-3. The total on-chip power consumed by the proposed 32-bit reversible floating point subtractor is 0.410 W. PMID:24455466

  15. PREDICTIVE PHARMACOKINETICS OF TRAMADOL HYDROCHLORIDE FLOATING TABLETS.

    PubMed

    Wang, Jianming; Zhang, Yanzhen; Guo, Zhiling; Tao, Qingwen; Wang, Yongjun; Zhou, Wei; Ma, Xiao; Li, Zhihong

    2016-01-01

    The purpose of this study was to propose the effectiveness of convolution approach to predict pharmacokinetics of tramadol hydrochloride floating tablets, prepared by using various ratios of carbopol, HPMC K100M, and Hibiscus rosa Sinensis as excipient. The in vitro dissolution test was conducted using paddle method in 900 mL of HCl buffer with pH 1.2 to simulate the gastric condition. The stirring speed of paddles was set at 70 rpm. Temperature of dissolution medium was adjusted at 37 ± 5 °C. At predetermined time points, 5 mL of dissolution samples were taken with a replacement of same volume using fresh medium. The obtained samples were analyzed at 271 nm using UV visible spectrophotometer. The values of predicted pharmacokinetic parameters like Cmax (maximum blood drug level), Tmax (time required to attain maximum blood drug level), and AUC (area under blood drug concentration curve) ranged between 80.8 ± 3.2-119.6 ± 4.7 ng/mL, 11.4 ± 0.2-12.2 ± 0.2 h, and 1430.5 ± 209.5-1970.6 ± 287.4 ng.h/mL, respectively. This certainly is a desired feature required at the formulation development step, where the formulator requires the development of a formulation using desired in vivo features on the basis of only accessible in vitro data. It can be concluded from the results that convolution method is a practical method for the prediction of drug concentration in blood and for quality control. PMID:27476294

  16. Free-floating atmospheric pressure ball plasmas

    NASA Astrophysics Data System (ADS)

    Wurden, G. A.; Ticos, C.; Wang, Z.; Wurden, C. J. V.

    2007-11-01

    A long-lived (0.3 second, 10-20 cm diameter) ball plasma floating in the air above a water surface has been formed and studied in the laboratory. A 0.4 - 1 mF capacitor is charged to 4-5 kV, and subsequently discharged (30-60 Amps, 20-50 msec duration) into central copper cathode held fixed just below the surface of a bucket of water (with a weak solution of various salts in distilled water, such as CuSO4 or CuCl2, LiCl or NaCl). An underwater ring anode completes the circuit. A bubble of hot vapor from the water surface rises up in the first few milliseconds, and changes from a mushroom cloud with stalk, to a detached quasi-spherical object, finally evolving into a vortex ring. The plasma consists of ionized water vapor, with positive salts and OH- radicals, as well as molecular species, and it completely excludes nitrogen or oxygen from the rising plasma structure. A fine boundary layer is visible in orange, in contrast to a green ball interior when using Cu/CuSO4, and filamentary structures are visible at late times. Finally, a whisp of smoke ring is observed as a residue. A variety of visible and infrared imaging (both video and still cameras) are used, along with 200-800 nm time & space resolved spectroscopy, to identify features of this laboratory analog to ball lightning. Possible applications include a windowless ball- plasma powered pulsed copper vapor laser operating at 510 nm.

  17. [Epidemiology of myopia].

    PubMed

    Pechmann, A; Czepita, D

    2000-01-01

    The present state of knowledge on the epidemiology of myopia is discussed. The history of myopia investigations is described. The prevalence of myopia in different ages, races and populations is presented. The factors influencing myopia occurrence are characterized. Special attention is focused on the results of studies indicating environmental and genetic reasons of myopia. Most recent investigations concerning the influence of light on myopia occurrence as well as concerning a genetic locus for high myopia are described. PMID:11291303

  18. Epidemiology of venous thromboembolism.

    PubMed Central

    Coon, W W

    1977-01-01

    This review of the epidemiology of venous thromboembolism includes estimates of incidence and prevalence of venous thrombosis and its sequelae, a discussion geographical, annual and seasonal variations and data concerning possible risk factors. Selection of patients at increased risk for development of deep venous thrombosis or pulmonary embolism for specific diagnostic screening or for prophylactic therapy with low-dose heparin may be a more effective approach to lowering morbidity and mortality from this disease. PMID:329779

  19. The leukemias: Epidemiologic aspects

    SciTech Connect

    Linet, M.S.

    1984-01-01

    Particularly geared to physicians and cancer researchers, this study of the epidemiology and etiology of leukemia analyzes the four major leukemia subtypes in terms of genetic and familial determinant factors and examines the incidence, distribution and frequency of reported leukemia clusters. Linet discusses the connection between other types of malignancies, their treatments, and the subsequent development of leukemia and evaluates the impact on leukemia onset of such environmental factors as radiation therapy, drugs, and occupational hazards.

  20. Epidemiology of Cystic Fibrosis.

    PubMed

    Spoonhower, Kimberly A; Davis, Pamela B

    2016-03-01

    Improved quality of care and rapidly emerging therapeutic strategies to restore chloride transport profoundly impact the epidemiology and pathobiology of cystic fibrosis (CF) in the twenty-first century. CF now serves as a model for chronic illness management, continuous quality improvement via registry data, and a seamless link between basic science research, translational studies, clinical trials, and outcomes research to enable rapid expansion of treatment options. PMID:26857763