Science.gov

Sample records for occult scaphoid fracture

  1. Imaging and treatment of scaphoid fractures and their complications.

    PubMed

    Taljanovic, Mihra S; Karantanas, Apostolos; Griffith, James F; DeSilva, Gregory L; Rieke, Joshua D; Sheppard, Joseph E

    2012-04-01

    The scaphoid is the most commonly fractured carpal bone, with frequent complications that are predisposed by its anatomical location, anatomical configuration (shape and length), and vascular supply. The most common mechanism of injury is a fall onto an outstretched hand. Imaging plays a significant role in the initial evaluation and treatment of scaphoid fractures and their complications. Radiography should be the first imaging modality in the initial evaluation and follow-up of scaphoid fractures. Computed tomography with its superb spatial resolution enables better visualization and characterization of the fracture line, and the amount of displacement and angulation of the fracture fragments. Using the metal reduction artifact with computed tomography allows good follow-up of scaphoid fractures despite surgical hardware. Magnetic resonance imaging without contrast is the imaging modality of choice for depiction of radiographically occult scaphoid fracture, bone contusion, and associated soft tissue injury; contrast-enhanced imaging aids assessment of scaphoid fracture nonunion, osteonecrosis, fracture healing after bone grafting, and revitalization of the necrotic bone after bone grafting. Proper identification and classification of scaphoid fracture and its complications is necessary for appropriate treatment. This article describes the normal anatomy, mechanism of injury, and classification of stable and unstable fractures, together with the imaging and treatment algorithm of scaphoid fractures and their complications with an emphasis on magnetic resonance imaging. PMID:22648431

  2. [Traumatology and diagnosis of scaphoid fracture].

    PubMed

    Schunk, K; Weber, W; Strunk, H; Regentrop, H; Thelen, R; Schild, H

    1989-02-01

    In 9 years, 1,104 patients had one or more roentgenological studies of the scaphoid; 252 fractures of the scaphoid were found. The most reported traumatic mechanism was a fall on the extended wrist. The form of fracture most seen was transverse fracture of the scaphoid; most of the fractures were found in the middle third of the scaphoid. The primary radiodiagnostic procedure should contain pictures of the wrist in two planes and four special pictures of the scaphoid. The "fat-pad sign" seems to be an unreliable indicator of fracture, but nearly two-thirds of fractures of the scaphoid showed a swelling of the soft tissues in the X-ray picture. PMID:2928508

  3. Coronal Fractures of the Scaphoid: A Review.

    PubMed

    Slutsky, David J; Herzberg, Guillaume; Shin, Alexander Y; Buijze, Geert A; Ring, David C; Mudgal, Chaitanya S; Leung, Yuen-Fai; Dumontier, Christian

    2016-08-01

    Coronal (or frontal plane) fractures of the scaphoid are distinctly uncommon. There are few published reports of coronal fractures of the scaphoid. This fracture is often missed on the initial X-ray films. A high index of suspicion should exist when there is a double contour of the proximal scaphoid pole on the anteroposterior X-ray view. A computed tomography scan is integral in making the diagnosis. Early recognition is key in salvaging the scaphoid fracture and in preventing articular damage. Level of Evidence IV. Retrospective case series. PMID:27574573

  4. [Scaphoid fracture in motocross riders].

    PubMed

    Knobloch, K; Krämer, R; Redeker, J; Spies, M; Vogt, P M

    2009-12-01

    Motocross racing is a demanding motorcycling discipline with significant physiological and psychological demands. Upper extremity injuries are frequently encountered. Interestingly, motocross riders present with a significantly stronger left arm, even if the left hand is not dominant. This difference is attributed to the use of the clutch lever with the left hand, which is more frequent in motocross than in Enduro or desert rally. The wrist has been reported to be involved especially among motocross racers in contrast to road racing. Besides wrist fractures, scaphoid fractures have been previously without a detailed analysis of the injury mechanism. We report on three patients suffering scaphoid fractures caused by extreme hyperextension of the wrist during landing after a motocross jump. Two patients presented late three months following the initial trauma (both Herbert type C fractures), while one motocross athlete with a B 2-type scaphoid fracture was admitted to wrist surgery within a week. The B 2-type fracture was treated with open reduction and Herbert-screw fixation, while the C-type fractures were treated by Herbert-screw fixation in addition to a cortico-cancellous bone graft. Within ten weeks after the surgery the patients were back in sport at their given preoperative level. Hyperextension rather than wrist flexion appears as the predominant mechanism of wrist injuries in motocross riders. A more axial impact on the wrist is more likely to produce a radial fracture during the landing phase. Preventive strategies are internal muscular wrist stabilisation using eccentric training and external stabilisation by rigid gloves allowing only limited hyperextension. PMID:20108186

  5. Diagnosis and treatment of scaphoid fractures.

    PubMed

    Patrick, Cynthia N

    2010-01-01

    The scaphoid bone in the wrist is the most frequently fractured carpal bone. This Directed Reading discusses types of scaphoid fractures, issues of special concern (eg, the risk of avascular necrosis and delayed union or non-union), steps involved in bone fracture healing and various imaging modalities used for scaphoid fracture diagnosis. Types of fracture management such as casting and surgical intervention are examined. Factors that can negatively influence bone healing, such as certain disease processes and tobacco use, are also investigated. This article is a Directed Reading. Your access to Directed Reading quizzes for continuing education credit is determined by your area of interest. For access to other quizzes, go to www.asrt.org/store. PMID:21048065

  6. A Scaphoid Stress Fracture in a Female Collegiate-Level Shot-Putter and Review of the Literature

    PubMed Central

    2016-01-01

    Scaphoid stress fractures are rare injuries that have been described in young, high-level athletes who exhibit repetitive loading with the wrist in extension. We present a case of an occult scaphoid stress fracture in a 22-year-old female Division I collegiate shot-putter. She was successfully treated with immobilization in a thumb spica splint for 6 weeks. Loaded wrist extension activities can predispose certain high-level athletes to sustain scaphoid stress fractures, and a high index of suspicion in this patient population may aid prompt diagnosis and management of this rare injury. PMID:27563477

  7. Comparison of conventional radiography and MDCT in suspected scaphoid fractures

    PubMed Central

    Behzadi, Cyrus; Karul, Murat; Henes, Frank Oliver; Laqmani, Azien; Catala-Lehnen, Philipp; Lehmann, Wolfgang; Nagel, Hans-Dieter; Adam, Gerhard; Regier, Marc

    2015-01-01

    AIM: To determine the diagnostic accuracy and radiation dose of conventional radiography and multidetector computed tomography (MDCT) in suspected scaphoid fractures. METHODS: One hundred twenty-four consecutive patients were enrolled in our study who had suffered from a wrist trauma and showed typical clinical symptoms suspicious of an acute scaphoid fracture. All patients had initially undergone conventional radiography. Subsequent MDCT was performed within 10 d because of persisting clinical symptoms. Using the MDCT data as the reference standard, a fourfold table was used to classify the test results. The effective dose and impaired energy were assessed in order to compare the radiation burden of the two techniques. The Wilcoxon test was performed to compare the two diagnostic modalities. RESULTS: Conventional radiography showed 34 acute fractures of the scaphoid in 124 patients (42.2%). Subsequent MDCT revealed a total of 42 scaphoid fractures. The sensitivity of conventional radiography for scaphoid fracture detection was 42.8% and its specificity was 80% resulting in an overall accuracy of 59.6%. Conventional radiography was significantly inferior to MDCT (P < 0.01) concerning scaphoid fracture detection. The mean effective dose of MDCT was 0.1 mSv compared to 0.002 mSv of conventional radiography. CONCLUSION: Conventional radiography is insufficient for accurate scaphoid fracture detection. Regarding the almost negligible effective dose, MDCT should serve as the first imaging modality in wrist trauma. PMID:25628802

  8. Fractures of the scaphoid, diagnosis and management--a review.

    PubMed

    Andjelković, Sladjana Z; Vucković, Cedo D; Lesić, Aleksandar R; Tulić, Goran C; Milutinović, Suzana M; Palibrk, Tomislav D; Zagorac, Slavisa G; Bumbasirević, Marko Z

    2013-01-01

    The scaphoid is vitally important for the proper mechanics of wrist function. Fracture of the scaphoid bone is the most common carpal fracture. Among all wrist injuries the incidence of scaphoid fracture is second only to fractures of the distal radius. Scaphoid fractures are significant because a delay in diagnosis can lead to a variety of adverse outcomes that include nonunion, delayed union, decreased grips strength, range of motion and osteoarthritis of the radiocarpal joint. To avoid missing this diagnosis, a high index of suspicion and a through history and physical examination are necessary, because initial radiographs are often negative. Regardless of the technique of bone grafting, there will almost always be some loss of motion even if the fracture unites. PMID:24298746

  9. Bilateral scaphoid stress fracture in a platform diver presenting with unilateral symptoms.

    PubMed

    Mohamed Haflah, Nor Hazla; Mat Nor, Noreen Fazlina; Abdullah, Shalimar; Sapuan, Jamari

    2014-10-01

    Scaphoid stress fracture is rare and occurs mainly in gymnasts. The current literature has only two reported cases: unilateral scaphoid stress fracture in a platform diver and bilateral scaphoid stress fracture in a gymnast. We herein report bilateral stress fracture of the scaphoid in a platform diver who presented with only one symptomatic side. Our patient was a 16-year-old competitive platform diver with an 18-month history of pain in the right wrist. Radiography revealed fracture of the right scaphoid at the waist. As part of our preoperative plan of measuring the scaphoid length to determine the appropriate screw, radiography of the contralateral side was performed, revealing an unexpected fracture of the left scaphoid. Due to the frequency of stress fractures in competitive sports, especially gymnastics, we recommend that bilateral scaphoid radiography be performed for athletes presenting with a unilateral scaphoid fracture, to avoid missing a fracture in the contralateral side. PMID:25631904

  10. Scaphoid fractures in children: problems and treatment.

    PubMed

    Toh, Satoshi; Miura, Hitoshi; Arai, Kouichi; Yasumura, Masahiro; Wada, Masayuki; Tsubo, Kenji

    2003-01-01

    From 1984 to 1999, the authors treated 64 cases of fracture of the scaphoid in children. Causes of injury were sports (n = 27), punching game machines or fighting (n = 22), and traffic accident or other trauma (n = 15). Most (46 cases) were nonunion cases. Eighteen cases were acute. Cast immobilization was performed in 10 acute cases and two nonunion cases. Screw fixation was performed in 52 cases, including 35 cases of bone graft. In 10 of these operated cases, freehand screw insertion was used. Ultimately, good bony fusion was achieved in all cases, but in two nonunion cases a secondary bone graft was necessary. Functional results in all cases were acceptable. A major problem is that children are not brought to clinics immediately after injury, so the percentage of nonunion is high. PMID:12604954

  11. Dorsal Plating of Unstable Scaphoid Fractures and Nonunions.

    PubMed

    Bain, Gregory I; Turow, Arthur; Phadnis, Joideep

    2015-09-01

    Achieving stable fixation of displaced acute and chronic nonunited scaphoid fractures continues to be a challenge for the treating surgeon. The threaded compression screw has been the mainstay of treatment of these fractures for the last 3 decades; however, persistent nonunion after screw fixation has prompted development of new techniques. Recent results of volar buttress plating have been promising. We describe a novel technique of dorsal scaphoid plating. In contrast to volar plating, the dorsal plate is biomechanically more favorable as it utilizes the tension side of the scaphoid bone for dynamic compression. Dorsal scaphoid plating provides a more stable construct than the traditional Herbert screw and mitigates the need for vascular or corticocancellous bone grafting in most cases. PMID:26053203

  12. Dual energy X-ray absorptiometry (DXA): can it detect acute scaphoid fractures?

    PubMed

    Stephen, A B; Pye, D; Lyons, A R; Oni, J A; Davis, T R C

    2005-02-01

    This prospective study investigated whether dual energy X-ray absorptiometry (DXA) could detect acute scaphoid fractures. We blindly compared 10 normal and 10 fractured scaphoid images produced with a new technique of DXA scan analysis. This measured and plotted the density of the scaphoid throughout its length, producing a linear graph of the scaphoids' density instead of a single area (g/cm2) measurement of bone density. These new plots only detected six of the 10 fractures and suggested that four of the normal controls were fractured. Thus, this technique of DXA scan analysis is neither sensitive nor specific for the detection of acute scaphoid fractures. PMID:15620498

  13. Union of Scaphoid Waist Fractures Assessed by CT Scan

    PubMed Central

    Clementson, Martin; Jørgsholm, Peter; Besjakov, Jack; Björkman, Anders; Thomsen, Niels

    2015-01-01

    Background Union of a scaphoid fracture is difficult to assess on a standard series of radiographs. An unnecessary and prolonged immobilization is inconvenient and may impair functional outcome. Although operative treatment permits early mobilization, its influence on time to union is still uncertain. Purpose To assess union of scaphoid waist fractures based on computed tomography (CT) scan at 6 weeks, and to compare time to union between conservative treatment and arthroscopically assisted screw fixation. Patients and methods CT scan in the longitudinal axis of the scaphoid was used to provide fracture characteristics, and to assess bone union at 6 weeks in 65 consecutive patients with scaphoid waist fractures. In a randomized subgroup from this cohort with nondisplaced fractures, we compared time to union between conservative treatment (n = 23) and arthroscopically assisted screw fixation (n = 15). Results Overall, at 6 weeks we found a 90% union rate for non- or minimally displaced fracture treated conservatively, and 82% for those who underwent surgery. In the randomized subgroup of nondisplaced fractures, no significant difference in time to union was demonstrated between those treated conservatively and those who underwent surgery. The conservatively treated fractures from this subgroup with prolonged time to union (10 to 14 weeks) were comminuted, demonstrating a radial cortical or corticospongious fragment. Conclusion The majority of non- or minimally displaced scaphoid waist fractures are sufficiently treated with 6 weeks in a cast. Screw fixation does not reduce time to fracture union compared with conservative treatment. Level of Evidence level II, Therapeutic study PMID:25709879

  14. Methods of imaging the scaphoid.

    PubMed

    Plancher, K D

    2001-11-01

    Rapid diagnosis of a scaphoid fracture is important so that proper treatment may be initiated. The high frequencies of nonunion of proximal pole, AVN, and scaphoid fractures warrant the use of special imaging to identify an occult fracture that may cause a long-term disability if not diagnosed. The modalities discussed allow the reader to treat patients in an expeditious and accurate manner. PMID:11775481

  15. Fracture of the Scaphoid During a Bench-Press Exercise.

    PubMed

    Mason, John S; Crowell, Michael S; Goss, Donald L

    2015-08-01

    The patient was a 21-year-old male cadet at a military academy who was evaluated by a physical therapist in a direct-access capacity for a chief complaint of left wrist pain that began 1 day after injuring his wrist while performing a bench-press exercise. Due to concern for a scaphoid fracture and because radiographic imaging was not immediately available, a physical therapist credentialed to utilize fluoroscopy evaluated the left wrist. Radiographs were subsequently ordered, which confirmed a mid-waist, nondisplaced scaphoid fracture. PMID:26232322

  16. Scaphoid fracture in a patient after a fall.

    PubMed

    Buscema, Christopher J

    2012-06-01

    The patient was a 27-year-old man who was referred to a physical therapist because of persistent right wrist pain after a fall on an outstretched hand in a remote setting 3 months prior. Immediately after the injury, the patient was seen by a physician's assistant in a remote medical clinic, where right wrist radiographs were completed and interpreted as normal. Based on the history and physical exam, a potential scaphoid fracture was suspected. Therefore, the physical therapist ordered radiographs of the right wrist, which revealed a fracture through the waist of the right scaphoid with a band-like lucency. PMID:22660578

  17. The clinical outcome of scaphoid fracture malunion at 1 year.

    PubMed

    Forward, D P; Singh, H P; Dawson, S; Davis, T R C

    2009-02-01

    The aim of this study was to assess the effect of malunion of scaphoid fractures on the clinical outcome at 1 year. Forty-two consecutive patients with united scaphoid waist fractures which had been treated non-operatively underwent longitudinal CT scans to confirm union and assess malunion at 12 to 18 weeks after injury. A blind clinical assessment was made and the Patient Evaluation Measure (PEM) and DASH questionnaires were completed by all the patients 1 year after injury. The group consisted of 38 men and four women with a mean age of 31 years at the time of injury. Correlation analysis revealed no significant relationships between any of the outcome measures (range of motion, grip strength and PEM and DASH scores) and any of the three measures of malunion (height-to-length ratio, the dorsal cortical angle and the lateral intra-scaphoid angle). PMID:19129358

  18. SCAPHOID STRESS FRACTURE IN GYMNASTICS ATHLETE: A CASE REPORT

    PubMed Central

    Nakamoto, João Carlos; Saito, Mateus; Cunha, Ana Paula; Luques, Isabela Ugo

    2015-01-01

    We present a case report of an 18 year-old gymnast who was diagnosed with a scaphoid stress fracture associated with a distal radial epiphysiolysis, reporting the treatment of choice. After a brief literature review about this rare association, the authors ask for attention concerning the importance of physical and image examination in making right diagnosis and finding associated injuries. PMID:27077066

  19. Office orthopedics: thumb spica casting for scaphoid fractures.

    PubMed

    Richard, J R

    1995-09-15

    Fracture of the scaphoid bone of the wrist is a common orthopedic problem and is accurately diagnosed by determining the mechanism of injury based on the history, performing a specific physical examination maneuvers and interpreting radiographic findings. Skill in the application of the thumb spica cast enables the family physician to provide appropriate and definitive care for many of these patients. PMID:7668203

  20. Treatment of scaphoid waist fractures with the HCS screw

    PubMed Central

    Gehrmann, Sebastian V.; Grassmann, Jan-Peter; Wild, Michael; Jungbluth, Pascal; Kaufmann, Robert A.; Windolf, Joachim; Hakimi, Mohssen

    2014-01-01

    The aim of the study was to evaluate the clinical results of the Headless Compression Screw (HCS, Synthes) when used for treatment of acute scaphoid waist fractures. The new screw design generates interfragmentary compression with use of a compression sleeve. Twenty-one patients were treated for acute scaphoid waist fractures type B2 with HCS screws. The average time to the final follow-up examination was 12.8 months. All 21 fractures united after a mean time of 7.2 weeks. The mean DASH score was 7.1. The average motion of the wrist in extension was 61°, flexion was 46°, radial abduction reached 25° and the ulnar abduction was 31°. The maximally achieved grip strength was 86% compared to the uninjured side. Treatment of type B2 scaphoid fractures with the Headless Compression Screw showed good functional and radiographic results. The results are similar to those identified using other screw fixation systems. PMID:26504721

  1. Scaphoid Fracture Fixation with an Acutrak(®) Screw.

    PubMed

    Loving, Vilert A; Richardson, Michael L

    2006-01-01

    We report a case of fixation of a scaphoid fracture using an Acutrak(®) screw. This screw is cannulated and headless, which allows it to be implanted below the surface of the bone. It uses the same concept of variable thread pitch as the Herbert screw, but unlike the Herbert screw, is fully threaded, with continuously varying pitch along its length. This variable pitch creates constant compression across a fracture as the screw is advanced, and gives the screw its unique appearance. This feature may improve internal holding power, as well as allow a fracture or osteotomy site to lie anywhere along the length of the screw. PMID:27298683

  2. Chronic wrist pain in a goalkeeper; bilateral scaphoid stress fracture: A case report

    PubMed Central

    Saglam, Fevzi; Gulabi, Deniz; Baysal, Özgür; Bekler, Halil İbrahim; Tasdemir, Zeki; Elmali, Nurzat

    2014-01-01

    Introduction Bilateral scaphoid stress fractures are uncommon, and rarely presented with chronic wrist pain. Most fractures of the scaphoid heal with immobilization. Presentation of case The case presented here is of a bilateral stress fractures of the carpal scaphoid in a 19-year-old male.The patient had been playing as a goalkeeper and presented with a 4-year history of chronic pain in both wrists. We had a successful result in the treatment of these stress fractures with long- arm thumb plaster cast.Discussion Most fractures of the scaphoid in the immature skeleton heal with immobilization. Approximately 88–95% of acute scaphoid fractures are said to heal with conservative treatment using cast immobilisation. Non-surgical treatment is successful for scaphoid fractures in children and for those fractures which are non-displaced, stable, and where there is no damage to other bones or ligaments. In stable fractures, union is achieved within 8–12 weeks.Conclusion Bilateral stress fractures of the scaphoid can be considered for the wrist pain, especially for the patients that had repetitive minor wrist trauma, and in spite of developments in surgical techniques and materials used, treatment by plaster casting should still be considered initially for non-displaced, stable scaphoid stress fractures. PMID:25562597

  3. Trans-Scaphoid Perilunate Fracture Dislocation; A Technical Note

    PubMed Central

    Aslani, Hossein; Bazavar, Mohammad Reza; Sadighi, Ali; Tabrizi, Ali; Elmi, Asghar

    2016-01-01

    Carpal fracture-dislocation is regarded as an unusual orthopedic injury and, thus, orthopedic surgeons are less experienced in dealing with and treating these fractures and dislocations. We report a 20-year-old worker man suffering from an unusual carpal fracture-dislocation. There was trans-scaphoid fracture and lunate dislocation with other carpal proximal bones toward volar of the wrist. Two volar and dorsal approaches were used to treat and stabilize the fracture. It was completely stabilized after open reduction and fixation using several pins. After two days, neural symptoms were completely recovered and the patient was discharged. Postoperative radiographies revealed complete restitution of lesser and greater arcs and normalization of Gilula's line. Scapholunate and lunatocapitate angles reached to less than 60° and 10°, respectively. The combined approach had favorable results for treatment of this unusual type of carpus fracture dislocation. However longer follow up is need to evaluate the arthritis and degenerative changes in wrist. PMID:27331069

  4. Classifications of Acute Scaphoid Fractures: A Systematic Literature Review.

    PubMed

    Ten Berg, Paul W; Drijkoningen, Tessa; Strackee, Simon D; Buijze, Geert A

    2016-05-01

    Background In the lack of consensus, surgeon-based preference determines how acute scaphoid fractures are classified. There is a great variety of classification systems with considerable controversies. Purposes The purpose of this study was to provide an overview of the different classification systems, clarifying their subgroups and analyzing their popularity by comparing citation indexes. The intention was to improve data comparison between studies using heterogeneous fracture descriptions. Methods We performed a systematic review of the literature based on a search of medical literature from 1950 to 2015, and a manual search using the reference lists in relevant book chapters. Only original descriptions of classifications of acute scaphoid fractures in adults were included. Popularity was based on citation index as reported in the databases of Web of Science (WoS) and Google Scholar. Articles that were cited <10 times in WoS were excluded. Results Our literature search resulted in 308 potentially eligible descriptive reports of which 12 reports met the inclusion criteria. We distinguished 13 different (sub) classification systems based on (1) fracture location, (2) fracture plane orientation, and (3) fracture stability/displacement. Based on citations numbers, the Herbert classification was most popular, followed by the Russe and Mayo classifications. All classification systems were based on plain radiography. Conclusions Most classification systems were based on fracture location, displacement, or stability. Based on the controversy and limited reliability of current classification systems, suggested research areas for an updated classification include three-dimensional fracture pattern etiology and fracture fragment mobility assessed by dynamic imaging. PMID:27104083

  5. Retrospective review of 234 scaphoid fractures and nonunions treated with arthroscopy for union and complications.

    PubMed

    Slade, J F; Gillon, T

    2008-01-01

    The purpose of this paper is to retrospectively review 234 consecutive cases of scaphoid fractures and nonunions treated using arthroscopy with the dorsal percutaneous implantation of a headless compression screw for healing and complications. Solid union of fracture is determined by CT scan. We identified 126 acute injuries, including 65 proximal pole fractures; 67 grossly displaced fractures; 12 trans-scaphoid perilunate dislocations including four trans-scaphoid trans-capitate fractures; and ten combined scaphoid and distal radius fractures. 108 scaphoid nonunions were identified. 98 were correctly aligned and ten had a humpback deformity which was correctable using arthroscopic assisted reduction techniques at the time of surgery. 82 presented with a fracture gap 2mm or greater requiring percutaneous bone grafting. 12 cases of avascular necrosis (AVN) were identified by MRI. 20 nonunions had surgery performed at other institutions. The mean time to surgery for the nonunions was 20 months. 99% union rate of acute scaphoid fractures was obtained by 12 weeks, as determined by CT scan. Two complications were identified (3%). One case of delayed healing was identified. this delayed union was treated with percutaneous bone grafting and continued on to heal uneventfully. The other complication was a case of volar trans-scaphoid peri-lunate dislocation. While the fracture healed, the patient developed a traumatic dislocation requiring a capitate-lunate arthrodesis. Treatment of scaphoid nonunions resulted in ten cases of delayed healing, which were treated with repeat percutaneous bone grafting. This represented a 9% complication rate. of the ten cases of delayed unions that were re-bone grafted, four failed to heal by nine months. This resulted in a 96% union rate of our nonunion group by nine months. when acute fracture healing was compared to nonunions the average healing of acute fractures as determined by CT scanning measuring trabecular bridging was 12 weeks

  6. A new mechanism of injury for scaphoid fractures: 'test your strength' punch-bag machines.

    PubMed

    Sutton, P A; Clifford, O; Davis, T R C

    2010-06-01

    We investigated the mechanism of injury in a consecutive series of 153 confirmed scaphoid fractures. We found that ten (6%) occurred as a result of using a 'test your strength' punch-bag machine, a device found in public houses and amusement arcades. Clinicians should be aware that scaphoid fractures can occur as a result of punching these machines or other similar objects. PMID:20100710

  7. Imaging of Scaphoid Fractures According to the New S3 Guidelines.

    PubMed

    Schmitt, R; Rosenthal, H

    2016-05-01

    Up to 30 % of acute scaphoid fractures are missed in conventional radiography. CT and MRI should be early performed in the diagnostic workflow, when radiograms (dorsopalmar, lateral and Stecher's views) are negative or inconclusive in fracture detection. Significance of CT is different from that of MRI: Sensitivity of CT imaging (85 to 95 %) is superior to conventional radiography (about 70 %), but inferior to MRI (almost 100 %). However, CT (specificity 95 to 100 %) is able to provide more detailed anatomic information of the fracture pattern when compared to MRI (specificity 80 to 90 %). Particularly, differentiation of bone contusion ("bone bruise") and non-displaced fracture can be difficult in MRI. Thus, CT indication is not only given for fracture detection, but also for assessing the morphology in scaphoid fractures (localization, fragment dislocation, comminuted zones) and the fragment instability, too. MRI should be limited to equivocal trauma cases presenting pain in the snuff box, but with inconclusive CT findings. In CT and MRI of scaphoid fractures, image display must be aligned along the longitudinal extension of the scaphoid, either by acquiring or reformatting oblique-sagittal and oblique-coronal planes. Key points • Radiography can be limited to the dorsopalmar, lateral and Stecher's views in scaphoid fractures.• In CT and MR imaging, the dedicated anatomy of the scaphoid has to be covered with oblique-sagittal and oblique-coronal images.• CT provides most detailed information of scaphoid fractures (localization, fragment dislocation and instability pattern). However, its capability in detecting non-displaced fractures is inferior to MRI.• All scaphoid fractures are seen in MRI. But differentiation of bone contusion (bone bruise) and a non-displaced fracture can be crucial.• This order is recommended in the diagnostic algorithm of scaphoid fractures: 1. radiography, 2. CT, and 3. MRI. Citation Format:

  8. Evaluation for Occult Fractures in Injured Children

    PubMed Central

    French, Benjamin; Song, Lihai; Feudtner, Chris

    2015-01-01

    OBJECTIVES: To examine variation across US hospitals in evaluation for occult fractures in (1) children <2 years old diagnosed with physical abuse and (2) infants <1 year old with injuries associated with a high likelihood of abuse and to identify factors associated with such variation. METHODS: We performed a retrospective study in children <2 years old with a diagnosis of physical abuse and in infants <1 year old with non-motor vehicle crash–related traumatic brain injury or femur fractures discharged from 366 hospitals in the Premier database from 2009 to 2013. We examined across-hospital variation and identified child- and hospital-level factors associated with evaluation for occult fractures. RESULTS: Evaluations for occult fractures were performed in 48% of the 2502 children with an abuse diagnosis, in 51% of the 1574 infants with traumatic brain injury, and in 53% of the 859 infants with femur fractures. Hospitals varied substantially with regard to their rates of evaluation for occult fractures in all 3 groups. Occult fracture evaluations were more likely to be performed at teaching hospitals than at nonteaching hospitals (all P < .001). The hospital-level annual volume of young, injured children was associated with the probability of occult fracture evaluation, such that hospitals treating more young, injured patients were more likely to evaluate for occult fractures (all P < .001). CONCLUSIONS: Substantial variation in evaluation for occult fractures among young children with a diagnosis of abuse or injuries associated with a high likelihood of abuse highlights opportunities for quality improvement in this vulnerable population. PMID:26169425

  9. The scaphoid.

    PubMed

    Sendher, Rosie; Ladd, Amy L

    2013-01-01

    The scaphoid is vitally important for the proper mechanics of wrist function. Its unique morphology from its boat like shape to its retrograde blood supply can present with challenges in the presence of a fracture. Almost completely covered with articular cartilage, this creates precise surface loading demands and intolerance to bony remodeling. Fracture location compounds risk of malunion and non-union. Scaphoid fractures may significantly impair wrist function and activities of daily living, with both individual and economic consequences. PMID:23174330

  10. Occult Intertrochanteric Fracture Mimicking the Fracture of Greater Trochanter

    PubMed Central

    Chung, Phil Hyun; Kang, Suk; Kim, Jong Pil; Kim, Young Sung; Back, In Hwa; Eom, Kyeong Soo

    2016-01-01

    Purpose Occult intertrochanteric fractures are misdiagnosed as isolated greater trochanteric fractures in some cases. We investigated the utility of three-dimensional computed tomography (3D-CT) and magnetic resonance imaging (MRI) in the diagnosis and outcome management of occult intertrochanteric fractures. Materials and Methods This study involved 23 cases of greater trochanteric fractures as diagnosed using plain radiographs from January 2004 to July 2013. Until January 2008, 9 cases were examined with 3D-CT only, while 14 cases were screened with both 3D-CT and MRI scans. We analyzed diagnostic accuracy and treatment results following 3D-CT and MRI scanning. Results Nine cases that underwent 3D-CT only were diagnosed with isolated greater trochanteric fractures without occult intertrochanteric fractures. Of these, a patient with displacement received surgical treatment. Of the 14 patients screened using both CT and MRI, 13 were diagnosed with occult intertrochanteric fractures. Of these, 11 were treated with surgical intervention and 2 with conservative management. Conclusion Three-dimensional CT has very low diagnostic accuracy in diagnosing occult intertrochanteric fractures. For this reason, MRI is recommended to confirm a suspected occult intertrochanteric fracture and to determine the most appropriate mode of treatment.

  11. Scaphoid fracture fixation: localization of bones through statistical model to ultrasound registration

    NASA Astrophysics Data System (ADS)

    Anas, Emran Mohammad Abu; Rasoulian, Abtin; St. John, Paul; Pichora, David; Mousavi, Parvin; Lessoway, Victoria A.; Seitel, Alexander; Hacihaliloglu, Ilker; Rohling, Robert; Abolmaesumi, Purang

    2015-03-01

    Percutaneous treatment of scaphoid fractures has found increasing interest in recent years as it promises to minimize soft-tissue damage, and minimizes the risk of infections and the loss of the joint stability. However, as this procedure is mostly performed on 2D fluoroscopic images, the accurate localization of the scaphoid bone for fracture fixation renders extremely challenging. In this work, we thus propose the integration of a statistical wrist model with 3D intraoperative ultrasound for accurate localization of the scaphoid bone. We utilize a previously developed statistical wrist model and register it to bone surfaces in ultrasound images using a probabilistic approach that involves expectation-maximization. We utilize local phase symmetry to detect features in noisy ultrasound images; in addition, we use shadow information in ultrasound images to enhance and set apart bone from other features. Feasibility experiments are performed by registering the wrist model to 3D ultrasound volumes of two different wrists at two different wrist positions. And the result indicates a potential of the proposed technique for localization of the scaphoid bone in ultrasound images.

  12. Pulsed Electromagnetic Fields in the treatment of fresh scaphoid fractures. A multicenter, prospective, double blind, placebo controlled, randomized trial

    PubMed Central

    2011-01-01

    Background The scaphoid bone is the most commonly fractured of the carpal bones. In the Netherlands 90% of all carpal fractures is a fracture of the scaphoid bone. The scaphoid has an essential role in functionality of the wrist, acting as a pivot. Complications in healing can result in poor functional outcome. The scaphoid fracture is a troublesome fracture and failure of treatment can result in avascular necrosis (up to 40%), non-union (5-21%) and early osteo-arthritis (up to 32%) which may seriously impair wrist function. Impaired consolidation of scaphoid fractures results in longer immobilization and more days lost at work with significant psychosocial and financial consequences. Initially Pulsed Electromagnetic Fields was used in the treatment of tibial pseudoarthrosis and non-union. More recently there is evidence that physical forces can also be used in the treatment of fresh fractures, showing accelerated healing by 30% and 71% reduction in nonunion within 12 weeks after initiation of therapy. Until now no double blind randomized, placebo controlled trial has been conducted to investigate the effect of this treatment on the healing of fresh fractures of the scaphoid. Methods/Design This is a multi center, prospective, double blind, placebo controlled, randomized trial. Study population consists of all patients with unilateral acute scaphoid fracture. Pregnant women, patients having a life supporting implanted electronic device, patients with additional fractures of wrist, carpal or metacarpal bones and pre-existing impairment in wrist function are excluded. The scaphoid fracture is diagnosed by a combination of physical and radiographic examination (CT-scanning). Proven scaphoid fractures are treated with cast immobilization and a small Pulsed Electromagnetic Fields bone growth stimulating device placed on the cast. Half of the devices will be disabled at random in the factory. Study parameters are clinical consolidation, radiological consolidation

  13. Costs analysis and comparison of usefulness of acute MRI and 2 weeks of cast immobilization for clinically suspected scaphoid fractures

    PubMed Central

    Bergh, Torbjørn H; Steen, Knut; Lindau, Tommy; Soldal, Lars Atle; Bernardshaw, Soosaipillai V; Lunde, Lene; Lie, Stein Atle; Brudvik, Christina

    2015-01-01

    Background and purpose Fractures of the scaphoid are often not detected on initial plain radiographs. Conventional management of clinically suspected scaphoid fractures is cast immobilization for 2 weeks and then reassessment. Early MRI is a diagnostic alternative. We compared the cost and usefulness of the early MRI diagnostic strategy with that of conventional management. Patients and methods This prospective pseudo-randomized study included patients between 18 and 49 years of age who attended Bergen Accident and Emergency Department, Bergen, Norway during 1 year in 2009–2010, after sustaining an acute wrist trauma in the previous week and with a clinically suspected scaphoid fracture. 61 patients were investigated with acute MRI, while 63 patients received standard treatment as a control group. We used cost-minimization analysis to estimate the cost of the 2 patient groups. Results Concerning cost, there were no statistically significant differences in the total direct medical costs or in indirect costs between the groups. Concerning usefulness, patients in the MRI group without a fracture (n = 35) used a cast for fewer days (mean 1 day) than patients in the control group with no fractures (n = 52) (mean 14 days; p < 0.001). They had less than half the number of days on sick leave than patients in the control group (mean 7 days vs. 15 days; p = 0.002). Interpretation In a Norwegian setting, an early MRI was of value in patients with clinically suspected scaphoid fracture and normal plain radiographs. PMID:25409256

  14. [Scaphoid malunion].

    PubMed

    Saffar, P

    2008-01-01

    Scaphoid fracture and healing are often difficult to diagnose. The scaphoid bone may heal in an abnormal position and this malunion is usually in flexion and shortening. Fractures of the mid or distal part of the bone are mainly concerned. This malunion may be the cause of an alteration of the carpal mechanics and finally of osteoarthritis revealed by pain and decrease of motion and strength. The intrascaphoid angle of Amadio helps to calculate the magnitude of the deformity and to plan the correction. This malunion has to be corrected only if symptomatic. Two other types of malunions exist: healing with a rotation of the distal fragment, and healing with irregular contours which may also lead to arthritis. Correction of the malunion will be performed after having assessed precisely measurements of the deformity using comparative X-rays, special views, carpal indices and eventually a dedicated specific software. In the literature may be found a certain number of papers where scaphoid osteotomy combined with a trapezoidal bone graft and a bone fixation using a screw have been performed with success and healing for all cases. This procedure may be performed without hesitation for a symptomatic healed scaphoid, even if it has been operated before for nonunion. PMID:18586545

  15. An occult acetabular fracture preceding a femoral neck fracture.

    PubMed

    Lasanianos, Nikolaos; Kanakaris, Nikolaos; Giannoudis, Peter V

    2009-08-01

    This article describes the case of a 69-year-old patient with an occult acetabular fracture complicated by an ipsilateral femoral neck fracture occurring within 2 months. The acetabular fracture remained undiagnosed at examination due to insufficient clinical and radiographic data interpretation. The patient was assured of early mobilization that led to a fall and subsequent hip fracture. We focus on the potential reasons for the nondiagnosis of the acetabular fracture. Acetabular fractures in the elderly may occur after low-energy injuries. The lack of history of violent injury may lead to an incorrect diagnosis. Plain anteroposterior (AP) pelvis radiographs alone may prove an insufficient tool, especially in the hands of inexperienced personnel. As is characteristic, a retrospective review of the AP pelvis radiograph obtained after the first fall in our case revealed the undisplaced fracture of the anterior column that was missed initially. Combined fractures of the hip and the acetabulum are rarely described in the literature and are usually addressed by total hip arthroplasty (THA) alone. Similar fracture patterns that develop in 2 stages (2 injuries), as the 1 presented herein, are even more rare. The uniqueness of this combined fracture required a unique surgical treatment. The senior surgeon (P.V.G.) addressed the acetabular fracture separately to graft the anterior column fracture and facilitate union, as it was already 8 weeks old and the second fall had generated a further gap between the fragments. Stable fixation was felt appropriate prior to the THA. Thus, a double surgical approach was used. Six weeks postoperatively, the patient was able to perform full weight-bearing mobilization without an antalgic gait pattern. At 6-month follow-up, radiographs showed the metalwork to be in place with no displacement, and the fracture had progressed to union. PMID:19708620

  16. The Role of Lunate Morphology on Scapholunate Instability and Fracture Location in Patients Treated for Scaphoid Nonunion

    PubMed Central

    Kim, Byoung-Jin; Kovacevic, David; Lee, Young-Min; Seol, Jong-Hwan

    2016-01-01

    Background To determine the association between lunate morphology and the scapholunate instability using radiographic images, and investigate the association between lunate morphology and scaphoid fracture location. Methods Between January 2003 and December 2011, we retrospectively evaluated the plain radiographs and computed tomography (CT) images of 70 patients who underwent surgical intervention for a scaphoid nonunion, in order to determine the association between lunate type (I or II) and scapholunate instability or scaphoid fracture location. We determined the scaphoid fracture location using the fragment ratio and measured the radiolunate angle and capitate-triquetrum (C-T) distance. Results A type II lunate was present in 68.6% (48 of 70 cases). Mean fragment ratio of fracture location was 50.6% in the type II lunate group and 56.2% in the type I lunate group (p = 0.032). Sixteen of the 70 patients had dorsal intercalated segmental instability (DISI) deformities. Nine of 22 cases showed DISI deformity in type I lunate and 7 of 48 cases showed DISI deformity in type II lunate (p = 0.029). However, there were no significant differences between the presence of DISI deformity and fracture location (p = 0.15). Morphologic comparisons by both plain radiography and CT indicated a mean C-T distance in the type I lunate group (22 cases) of 2.3 mm and 5.0 mm in the type II lunate group (48 cases). The C-T distances were significantly correlated with lunate morphology (p = 0.001). Conclusions A type II lunate was associated with low incidence of DISI deformity and proximal location of fracture in patients presenting with a scaphoid nonunion. PMID:27247743

  17. Optimization of volar percutaneous screw fixation for scaphoid waist fractures using traction, positioning, imaging, and an angiocatheter guide.

    PubMed

    Zlotolow, Dan A; Knutsen, Elisa; Yao, Jeffrey

    2011-05-01

    Percutaneous screw fixation of nondisplaced or reducible scaphoid fractures has become more popular as techniques and implants have improved. Many authors have advocated for the dorsal approach, citing difficulties with adequate screw placement from the volar approach. We have developed a straightforward and reproducible technique for volar percutaneous scaphoid screw fixation that mitigates most of the drawbacks of the approach. The wrist is held in extension and ulnar deviation with traction through the thumb. A 14-gauge angiocatheter needle is then used to localize the starting point and as a cannula for the guide wire. Specific fluoroscopic views help to confirm optimal guide wire placement. PMID:21527146

  18. Bone scanning in the detection of occult fractures

    SciTech Connect

    Batillas, J.; Vasilas, A.; Pizzi, W.F.; Gokcebay, T.

    1981-07-01

    The potential role of bone scanning in the early detection of occult fractures following acute trauma was investigated. Technetium 99m pyrophosphate bone scans were obtained in patients with major clinical findings and negative or equivocal roentgenograms following trauma. Bone scanning facilitated the prompt diagnosis of occult fractures in the hip, knee, wrist, ribs and costochondral junctions, sternum, vertebrae, sacrum, and coccyx. Several illustrative cases are presented. Roentgenographic confirmation occurred following a delay of days to weeks and, in some instances, the roentgenographic findings were subtle and could be easily overlooked. This study demonstrates bone scanning to be invaluable and definitive in the prompt detection of occult fractures.

  19. The influence of wire positioning upon the initial stability of scaphoid fractures fixed using Kirschner wires A finite element study.

    PubMed

    Ezquerro, F; Jiménez, S; Pérez, A; Prado, M; de Diego, G; Simón, A

    2007-07-01

    A finite element model of the carpal scaphoid and its joints was developed to study how wire positioning affects the initial stability of the fixation of scaphoid waist fractures using Kirschner wires. A transverse fracture of the scaphoid waist was simulated along with its fixation using five different two-wire configurations. The resulting models were subjected to a load simulating a 200N force passing through the wrist. Friction between bony fragments was taken into account; as the friction coefficient of cancellous bone is unknown, three different values were analysed. For each of these friction coefficient values, the smallest transverse interfragmentary displacements, and consequently maximum initial stability, were obtained for the model that simulated the maximum gap between wires in the plane of fracture. Results also show that for a similar gap in the plane of fracture, more stable fixation can be achieved when wires cross each other not only in the frontal plane of the hand, but also perpendicularly to it. PMID:17067844

  20. [Pitfalls in the diagnosis of occult elbow fractures in children].

    PubMed

    Courvoisier, A; Calvelli, N; Bourgeois, E; Eid, A; Griffet, J

    2016-08-01

    Elbow injuries are frequent but occult fractures are difficult to diagnose on x-rays. However, any delay in the diagnosis may severely impair the prognosis of some fractures. Simple tips may help the clinician read x-rays properly and avoid the classical pitfalls of elbow injuries in children. The chronology of appearance of ossification nuclei around the elbow is important to distinguish normal features from abnormality. Drawing simple geometric constructions on the x-rays may clarify most occult elbow fractures in children. PMID:27345552

  1. CT scan-evaluated outcome of pulsed electromagnetic fields in the treatment of acute scaphoid fractures: a randomised, multicentre, double-blind, placebo-controlled trial.

    PubMed

    Hannemann, P F W; van Wezenbeek, M R; Kolkman, K A; Twiss, E L L; Berghmans, C H J; Dirven, P A M G M; Brink, P R G; Poeze, M

    2014-08-01

    We hypothesised that the use of pulsed electromagnetic field (PEMF) bone growth stimulation in acute scaphoid fractures would significantly shorten the time to union and reduce the number of nonunions in a randomised, double-blind, placebo-controlled multicentre trial. A total of 102 patients (78 male, 24 female; mean age 35 years (18 to 77)) from five different medical centres with a unilateral undisplaced acute scaphoid fracture were randomly allocated to PEMF (n = 51) or placebo (n = 51) and assessed with regard to functional and radiological outcomes (multiplanar reconstructed CT scans) at 6, 9, 12, 24 and 52 weeks. The overall time to clinical and radiological healing did not differ significantly between the active PEMF group and the placebo group. We concluded that the addition of PEMF bone growth stimulation to the conservative treatment of acute scaphoid fractures does not accelerate bone healing. PMID:25086123

  2. Diagnosis of occult radial head and neck fracture in adults.

    PubMed

    Pavić, Roman; Margetić, Petra; Hnatešen, Dijana

    2015-11-01

    The purpose of this study was to compare imaging modalities in the diagnosis of occult radial head and neck fractures and to assess the diagnostic value of ultrasound in diagnosing occult fractures of the radial head and neck. The study included 193 patients (101 male, 92 female) who were referred by trauma surgeons from January 2011 to July 2014 and presented with history of acute elbow trauma. The mean age of the patients was 37 years (range 15-82 years); 95 right and 98 left elbows were included in the study. Clinical examinations and standard radiograms were conducted. The anteroposterior radiographic view revealed no visible signs of fracture. The lateral radiographic view showed displacement of the anterior and posterior fat pads (fat pad sign) due to joint effusion, which is an indirect sign of fracture. In all 193 cases, ultrasound examination showed intraarticular effusion. In 176 cases (91%), there was effusion in both the olecranon bursa and the elbow joint. In 10 patients (5%), there was effusion only inside the elbow joint and in seven cases (4%) there was effusion only in the olecranon bursa. Cortical discontinuity (a direct sign of fracture) was clearly visualised in 157 cases (82%), in the radial neck in 108 cases and in the radial head in 49 cases. Ultrasound findings of fracture were questionable in 36 cases (18%). Step-off deformities, tiny avulsed bone fragments, double-line appearance of cortical margins, and diffuse irregularity of the bone surfaces were identified as auxiliary ultrasound findings (indirect signs of fracture). Standard radiograms were repeated after 7-10 days. In 184 cases (95%), there was a clearly visible fracture: a fracture of the radial neck in 111 cases (58%) and a fracture of non-displaced radial head in 73 cases (37%). In nine cases (5%), radial fracture was not confirmed on radiogram and MRI was performed in these patients. In conclusion, ultrasound imaging proved to be an effective method for diagnosing occult

  3. Comparison of Operative and Non-Operative Treatment of Acute Undisplaced or Minimally-Displaced Scaphoid Fractures: A Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Shen, Longxiang; Tang, Jianfei; Luo, Congfeng; Xie, Xuetao; An, Zhiquan; Zhang, Changqing

    2015-01-01

    Background Traditionally, acute undisplaced or minimally-displaced scaphoid fractures are treated by casting in short- or long-arm casts. Although reports have shown that operative treatment is safe, effective and produces satisfactory results, outcomes from current studies comparing these two methods are questionable. The aim of this meta-analysis was to evaluate the effects of operative versus non-operative treatment for acute undisplaced or minimally-displaced scaphoid fractures in adults. Methods Computerized searches were performed without language restrictions and all randomized controlled studies providing information on the effects of operative versus non-operative treatment on the outcomes of acute undisplaced or minimally-displaced scaphoid fractures were included. The weighted and standard mean difference (WMD and SMD) or the relative risk (RR) were calculated for continuous or dichotomous data respectively. Results A total of six studies reported in seven publications were included, representing data on 340 fractures. Meta-analysis indicated that operative treatment resulted in significantly better functional outcomes in the short term when compared with non-operative treatment. Consistently, patients who accepted surgery had a more rapid return to work. Further, surgery was advantageous in preventing delayed union of the fractures, a finding supported by the results of analysis of the time to fracture union. A number-needed-to-treat analysis revealed that more than 20 patients would have to undergo operative treatment to prevent one delayed union. Conclusion Acute undisplaced or minimally-displaced scaphoid fractures demonstrate faster recovery with operative treatment; however, the current meta-analysis does not provide evidence supporting the routine use of operative treatment for all acute undisplaced or minimally-displaced scaphoid fractures. PMID:25942316

  4. Impact of Different Screw Designs on Durability of Fracture Fixation: In Vitro Study with Cyclic Loading of Scaphoid Bones

    PubMed Central

    Gruszka, Dominik; Herr, Robert; Hely, Hans; Hofmann, Peer; Klitscher, Daniela; Hofmann, Alexander; Rommens, Pol Maria

    2016-01-01

    Purpose The use of new headless compression screws (HCSs) for scaphoid fixation is growing, but the nonunion rate has remained constant. The aim of this study was to compare the stability of fixation resulting from four modern HCSs using a simulated fracture model to determine the optimal screw design(s). Methods We tested 40 fresh-frozen cadaver scaphoids treated with the Acumed Acutrak 2 mini (AA), the KLS Martin HBS2 midi (MH), the Stryker TwinFix (ST) and the Synthes HCS 3.0 with a long thread (SH). The bones with simulated fractures and implanted screws were loaded uniaxially into flexion for 2000 cycles with a constant bending moment of 800 Nmm. The angulation of the fracture fragments was measured continuously. Data were assessed statistically using the univariate ANOVA test and linear regression analysis, and the significance level was set at p < 0.05. Results The median angulation of bone fragments φ allowed by each screw was 0.89° for AA, 1.12° for ST, 1.44° for SH and 2.36° for MH. With regards to linear regression, the most reliable curve was achieved by MH, with a coefficient of determination of R2 = 0.827. This was followed by AA (R2 = 0.354), SH (R2 = 0.247) and ST (R2 = 0.019). Data assessed using an adapted ANOVA model showed no statistically significant difference (p = 0.291) between the screws. Conclusions The continuous development of HCSs has resulted in very comparable implants, and thus, at this time, other factors, such as surgeons’ experience, ease of handling and price, should be taken into consideration. PMID:26741807

  5. Radiographically Occult and Subtle Fractures: A Pictorial Review

    PubMed Central

    Roemer, Frank W.; Crema, Michel D.; Diaz, Luis; Conlin, Jane; Marra, Monica D.; Jomaah, Nabil; Guermazi, Ali

    2013-01-01

    Radiographically occult and subtle fractures are a diagnostic challenge. They may be divided into (1) “high energy trauma fracture,” (2) “fatigue fracture” from cyclical and sustained mechanical stress, and (3) “insufficiency fracture” occurring in weakened bone (e.g., in osteoporosis and postradiotherapy). Independently of the cause, the initial radiographic examination can be negative either because the findings seem normal or are too subtle. Early detection of these fractures is crucial to explain the patient's symptoms and prevent further complications. Advanced imaging tools such as computed tomography, magnetic resonance imaging, and scintigraphy are highly valuable in this context. Our aim is to raise the awareness of radiologists and clinicians in these cases by presenting illustrative cases and a discussion of the relevant literature. PMID:23577253

  6. [Pseudarthrosis of the scaphoid: frequency, pathogenesis and course].

    PubMed

    Schunk, K; Teifke, A; Benning, R; Dahm, M; Thelen, R; Schild, H

    1989-06-01

    Eight-three scaphoid pseudo-arthroses were found amongst 1.104 scaphoid examinations. Sixty-seven were present at the first examination and 16 pseudoarthroses developed amongst 252 scaphoid fractures. Men were affected predominantly, particularly in the 20 to 40-year old group. Fractures in the proximal third of the scaphoid and vertical oblique fractures had a particular tendency to pseudo-arthrosis formation. The operative treatment of choice is a Matti-Russe bone graft. Only one patient in seven with definite scaphoid pseudo-arthrosis showed firm fusion. PMID:2544938

  7. Occult fractures of the greater tuberosity of the humerus

    PubMed Central

    Carbone, S.; Postacchini, F.

    2008-01-01

    We studied the highest reported number of patients with occult fracture of the greater tuberosity of the humerus and we analysed why fracture was not diagnosed, shoulder function and prevalence of eventually associated rotator cuff tear (RCT). Twenty-four patients with a missed fracture of the greater tuberosity underwent MR study for a suspect RCT. We evaluated shoulder function and self-assessed comfort with the Constant score (CS) and Simple Shoulder Test (SST). Nine patients showed evidence of cuff tendinosis, 11 of partial (p) RCT (2: subscapularis; 6: supraspinatus and 3: supraspinatus and infraspinatus). All patients with pRCT were older than 40. Initially, the mean CS and SST were 54% and 5/12; at follow-up, values increased to 36% and 5 points. MR should be performed in patients apparently negative for fracture but with painful shoulders and decreased ROM. Of our patients, 45.8% had pRCT; nevertheless function recovery was verified in 16 weeks. PMID:18256834

  8. The Accuracy of Pain Measurement in Diagnosis of Scaphoid Bone Fractures in Patients with Magnetic Resonance Imaging: Report of 175 Cases

    PubMed Central

    Sharifi, Mohammad Davood; Moghaddam, Hamid Zamani; Zakeri, Hosein; Ebrahimi, Mohsen; Saeedian, Hesamoddin; Hashemian, Amir Masoud

    2015-01-01

    Introduction: Scaphoid fracture is the most common fracture among the bones of the wrist. Plain radiography has a sensitivity of 59 to 79 percent for the diagnosis of scaphoid fracture after injury. Casting is done to avoid complications in patients with suspected fractures with normal radiography. Magnetic resonance imaging (MRI) has a sensitivity of 100% and a specificity of 99%. To avoid unnecessary casting and high costs, we decided to offer a way more efficient than radiography and less costly than MRI. Material and Methods: In the present study, 175 patients with suspected scaphoid fracture along with snuff box tenderness and normal radiography were enrolled in the study. On arrival, patients’ pain score were determined using visual analog scale method with anatomical snuffbox tenderness and then MRI was performed on the patients’ wrist and the results were recorded for patient in the check list. The data was then aggregated and analyzed. Results: The result of MRI for fracture was negative for 90.9% and positive for 9.1%. The mean pain score was 7.3 in negative MRI group and 8.75 in positive MRI group, considering a significant difference. ROC curve graph showed that the sensitivity and specificity will be 87% and 57%, respectively for scores 7.5 and higher and 75% and 72%, respectively for scores 8.5 and higher. Conclusion: It seems that although this method, beside other criteria in the diagnosis of fractures, can be useful in future studies, it would not be helpful in fracture detection. PMID:26261383

  9. Anatomic Locking Plate Fixation for Scaphoid Nonunion

    PubMed Central

    Yeung, Just; Sapienza, Anthony

    2016-01-01

    Nonunion can occur relatively frequently after scaphoid fracture and appears to be associated with severity of injury. There have been a number of techniques described for bone grafting with or without screw fixation to facilitate fracture healing. However, even with operative fixation of scaphoid fractures with bone grafting nonunion or malunion rates of 5 to 10 percent are still reported. This is the first report of an anatomic locking plate for scaphoid fracture repair in a 25-year-old right hand dominant healthy male. PMID:27366338

  10. Bilateral scaphotrapezium-trapezoid coalition with bipartite scaphoid: case report.

    PubMed

    Stewart, David Alexander; McCombe, David

    2013-09-01

    We report on a 15-year-old girl with bilateral scaphotrapezium-trapezoid coalitions and bipartite scaphoids. There was no history of trauma or any other associated pathology. Wrist pain was alleviated by arthrodesis of the pseudarthrosis of the scaphoid component of the coalitions. Coalition of the distal portions of the scaphoids may have interfered with union of 2 ossification centers of the scaphoid. It is also possible that the carpal coalitions predisposed the scaphoid to fracture and that this represents bilateral nonunion. PMID:23932812

  11. Computer-assisted 3-dimensional anthropometry of the scaphoid.

    PubMed

    Pichler, Wolfgang; Windisch, Gunther; Schaffler, Gottfried; Heidari, Nima; Dorr, Katrin; Grechenig, Wolfgang

    2010-02-01

    Scaphoid fracture fixation using a cannulated headless compression screw and the Matti-Russe procedure for the treatment of scaphoid nonunions are performed routinely. Surgeons performing these procedures need to be familiar with the anatomy of the scaphoid. A literature review reveals relatively few articles on this subject. The goal of this anatomical study was to measure the scaphoid using current technology and to discuss the findings with respect to the current, relevant literature.Computed tomography scans of 30 wrists were performed using a 64-slice SOMATOM Sensation CT system (resolution 0.6 mm) (Siemens Medical Solutions Inc, Malvern, Pennsylvania). Three-dimensional reconstructions from the raw data were generated by MIMICS software (Materialise, Leuven, Belgium). The scaphoid had a mean length of 26.0 mm (range, 22.3-30.7 mm), and men had a significantly longer (P<.001) scaphoid than women (27.861.6 mm vs 24.561.6 mm, respectively). The width and height were measured at 3 different levels for volume calculations, resulting in a mean volume of 3389.5 mm(3). Men had a significantly larger (P<.001) scaphoid volume than women (4057.86740.7 mm(3) vs 2846.56617.5 mm(3), respectively).We found considerable variation in the length and volume of the scaphoid in our cohort. We also demonstrated a clear correlation between scaphoid size and sex. Surgeons performing operative fixation of scaphoid fractures and corticocancellous bone grafting for nonunions need to be familiar with these anatomical variations. PMID:20192143

  12. Absorbable scaphoid screw development: a comparative study on biomechanics

    PubMed Central

    Wang, Yi; Song, Muguo; Xu, Yongqing; He, Xiaoqing; Zhu, YueLiang

    2016-01-01

    Background The scaphoid is critical for maintaining the stability and movement of the wrist joints. This study aimed to develop a new internal fixator absorbable scaphoid screw (ASS) for fixation of the scaphoid waist after fracture and to test the biomechanical characteristics of ASS. Materials and methods An ASS was prepared using polylactic acids and designed based on scaphoid measurements and anatomic features. Twenty fractured scaphoid waist specimens were randomly divided into experimental and control groups (n=10/group). Reduction and internal fixation of the scaphoid were achieved with either Kirschner wires (K-wires) or ASS. A moving target simulator was used to test palmar flexion and dorsal extension, with the range of testing (waist movement) set from 5° of palmar flexion to 25° of dorsal extension. Flexion and extension were repeated 2,000 times for each specimen. Fracture gap displacements were measured with a computerized tomography scanning. Scaphoid tensile and bending strengths were measured by using a hydraulic pressure biomechanical system. Results Prior to biomechanical fatigue testing, fracture gap displacements were 0.16±0.02 mm and 0.22±0.02 mm in the ASS and K-wire groups, respectively. After fatigue testing, fracture gap displacements in the ASS and the K-wire groups were 0.21±0.03 mm and 1.52±0.07 mm, respectively. The tensile strengths for the ASS and K-wire groups were 0.95±0.02 MPa and 0.63±0.02 MPa, respectively. Conclusion Fixation using an ASS provided sufficient mechanical support for the scaphoid after fracture. PMID:27217756

  13. Occult fracture of the femoral neck associated with extensive osteonecrosis of the femoral head: A case report

    PubMed Central

    Fukui, Kiyokazu; Kaneuji, Ayumi; Matsumoto, Tadami

    2015-01-01

    Introduction Although the subchondral portion of the femoral head is a common site for collapse in osteonecrosis of the femoral head (ONFH), femoral-neck fracture rarely occurs during the course of ONFH. We report a case of occult insufficiency fracture of the femoral neck without conditions predisposing to insufficiency fractures, occurring in association with ONFH. Presentation of case We report a case of occult fracture of the femoral neck due to extensive ONFH in a 60-year-old man. No abnormal findings suggestive of ONFH were identified on radiographs, and the fracture occurred spontaneously without any trauma or unusual increase in activity. The patient’s medical history, age, and good bone quality suggested ONFH as a possible underlying cause. Contrast-enhanced magnetic resonance imaging was useful in determining whether the fracture was caused by ONFH or was instead a simple insufficiency fracture caused by steroid use. Discussion The patient was treated with bipolar hemiarthroplasty, but if we had not suspected ONFH as a predisposing condition, the undisplaced fracture might have been treated by osteosynthesis, and this would have led to nonunion or collapse of the femoral head. To avoid providing improper treatment, clinicians should consider ONFH as a predisposing factor in pathologic fractures of the femoral neck. Conclusion ONFH should be included in the differential diagnosis of insufficiency fracture of the femoral neck. PMID:26275737

  14. Computer-assisted percutaneous scaphoid fixation: concepts and evolution.

    PubMed

    Smith, Erin J; Ellis, Randy E; Pichora, David R

    2013-11-01

    Background The treatment for undisplaced scaphoid waist fractures has evolved from conventional cast immobilization to percutaneous screw insertion. Percutaneous fixation reduces some of the risks of open surgery, but can be technically demanding and carries the risk of radiation exposure. Recently, computer-assisted percutaneous scaphoid fixation (CAPSF) has been gaining interest. Materials and Methods Conventional percutaneous scaphoid fixation is performed under fluoroscopic guidance and involves insertion of a guide wire along the length of the scaphoid to facilitate placement of a cannulated screw. Adapting computer-assisted techniques for scaphoid fixation poses several unique challenges including patient tracking and registration. Results To date, five groups have successfully implemented systems for CAPSF. These systems have implemented wrist immobilization strategies to resolve the issue of patient tracking and have developed unique guidance techniques incorporating 2D fluoroscope, cone-beam CT, and ultrasound, to circumvent patient-based registration. Conclusions Computer-aided percutaneous pinning of scaphoid waist fractures can significantly reduce radiation exposure and has the potential to improve the accuracy of this procedure. This article reviews the rationale for, and the evolution of, CAPSF and describes the key principles of computer-assisted technology. PMID:24436833

  15. Computer-Assisted Percutaneous Scaphoid Fixation: Concepts and Evolution

    PubMed Central

    Smith, Erin J.; Ellis, Randy E.; Pichora, David R.

    2013-01-01

    Background The treatment for undisplaced scaphoid waist fractures has evolved from conventional cast immobilization to percutaneous screw insertion. Percutaneous fixation reduces some of the risks of open surgery, but can be technically demanding and carries the risk of radiation exposure. Recently, computer-assisted percutaneous scaphoid fixation (CAPSF) has been gaining interest. Materials and Methods Conventional percutaneous scaphoid fixation is performed under fluoroscopic guidance and involves insertion of a guide wire along the length of the scaphoid to facilitate placement of a cannulated screw. Adapting computer-assisted techniques for scaphoid fixation poses several unique challenges including patient tracking and registration. Results To date, five groups have successfully implemented systems for CAPSF. These systems have implemented wrist immobilization strategies to resolve the issue of patient tracking and have developed unique guidance techniques incorporating 2D fluoroscope, cone-beam CT, and ultrasound, to circumvent patient-based registration. Conclusions Computer-aided percutaneous pinning of scaphoid waist fractures can significantly reduce radiation exposure and has the potential to improve the accuracy of this procedure. This article reviews the rationale for, and the evolution of, CAPSF and describes the key principles of computer-assisted technology. PMID:24436833

  16. PSEUDARTHROSIS OF THE SCAPHOID IN IMMATURE SKELETONS

    PubMed Central

    de Lemos, Marcelo Barreto; Bentes, Ádria Simone Ferreira; Neto, Miguel Flores do Amaral; Spinelli, Leandro de Freitas; Severo, Antônio Lourenço; Lech, Osvandré

    2015-01-01

    This paper presents a review of the literature on pseudarthrosis of the scaphoid in skeletally immature individuals, taking into consideration its epidemiology, diagnosis and treatment, as well as its controversies. Knowledge of this subject makes it possible for patients to be given appropriate treatment immediately. Pseudarthrosis of the scaphoid in skeletally immature patients is a rare condition that results from error or lack of diagnosis of a fracture. Thus, careful clinical and radiographic examination should be performed in order to confirm or rule out this diagnosis. Several treatment methods have been reported and have shown good results. These include conservative plaster cast treatment, bone graft without osteosynthesis, bone graft with Kirschner wires, percutaneous screws and bone graft with compression screws. The treatment performed depends on the characteristics of the pseudarthrosis and the surgeon's experience. PMID:27042636

  17. Vascularized bone graft for scaphoid nonunions.

    PubMed

    Mih, Alexander D

    2004-09-01

    Scaphoid fracture nonunion remains a challenging problem that may persist despite traditional methods of bone grafting and internal fixation. The alteration of wrist mechanics created by nonunion as well as the development of avascular necrosis leads to degenerative change of the radiocarpal joint accompanied by loss of motion and pain. The use of a vascularized bone graft has the theoretical benefit of increased blood flow that exceeds that of nonvascularized grafts. Numerous sources of vascularized bone graft have been described, including those from remote sites as well as from the carpus and distal radius. Knowledge of the blood supply to the distal radius has allowed for development of several vascularized bone graft harvest sites. The results of vascularized bone grafting from the distal radius have been encouraging, with numerous authors reporting the successful treatment of scaphoid nonunions. PMID:16518108

  18. A case of pathologic fracture of femur whose primary tumor and occult metastases were ascertained by PET-CT.

    PubMed

    Yoo, Jae Ho; Yang, Bo Kyu; Kim, Jin Hong; Kim, Soyon; Kim, Eun Sil

    2009-02-01

    We report a case of metastatic pathologic fracture of femoral shaft, whose primary cancer was ascertained by positron emission tomography-computed tomography (PET-CT). The abnormally increased biological activity of the space-occupying lesion of the lung was clearly demonstrated by PET-CT. Moreover, the occult bony metastatic lesions were confirmed with evidence of altered biologic activity. The PET-CT should be regarded as a valuable work-up tool for the orthopaedic management of metastatic pathologic fracture of a skeleton, all-the-more as a functional metabolic imaging tool. PMID:18183409

  19. Scaphoid Fracture of the Wrist

    MedlinePlus

    ... It is very important to maintain full finger motion throughout the recovery period. Your doctor will provide ... may recommend hand therapy to help you regain motion and strength in your wrist. Even with therapy, ...

  20. Anthropometry of the Human Scaphoid Waist by Three-Dimensional Computed Tomography.

    PubMed

    Smith, Jennifer; Hofmeister, Eric P; Renninger, Christopher; Kroonen, Leo T

    2015-01-01

    Published measurements for the scaphoid are scarce. The purpose of this study is to define anthropometric norms for the waist of the scaphoid to assist in optimizing bone graft quantity and implant use. Computed tomography images of the wrist were reviewed by three surgeons. Anthropometric data were gathered, including the scaphoid waist diameter in two dimensions and the scaphoid waist volume. Each study was measured twice, allowing for determination of inter- and intraobserver reliability. Forty-three studies were examined (23 female and 20 male). Average measurements of the scaphoid waist were 11.28 ± 0.26 mm in the sagittal plane and 8.70 ± 0.17 mm in the coronal plane, and the waist volume was 715 ± 33.0 mm3. Specific measures of the narrowest portion of the scaphoid are provided by this study. Measurements of the scaphoid waist through the use of three-dimensional imaging are an accurate method with good inter- and intraobserver reliability. The measurements obtained from this study can be applied to guide graft and implant selection for treatment of scaphoid waist fractures and nonunions. PMID:26688990

  1. Transcapho perilunate dislocation with palmar extrusion of the scaphoid proximal pole.

    PubMed

    Marcuzzi, Augusto; Leigheb, Massimiliano

    2016-01-01

    Perilunate fracture-dislocations usually combine ligament ruptures, bone avulsions, and fractures in different patterns. Rarely a displaced fracture of the scaphoid can coexist with a scapho-lunate dissociation and can result in enucleation of the proximal pole. We report about a case of trans-scaphoid perilunate dislocation with palmar extrusion/enucleation of the scaphoid proximal pole, treated with scaphoid fracture open reduction and internal fixation with screw, scapho-lunate ligament repair with an anchor and vascularization of the scaphoid proximal pole with the 2nd intermetacarpal artery. At 52 months follow up we had good clinical and radiographic results. In conclusion, scientific literature including our experience about this rare complex lesion of the wrist is too weak to support an effective strategy of management but we think that the careful analysis of the single problems can be the key to solve the complexity. Goal of the treatment should be complete revascularization and healing of the scaphoid, avoiding non union and avascular necrosis; simultaneously a proper ligament reconstruction is fundamental to re-establish carpal stability. Prevention of carpal collapse for a SNAC o SLAC situation is essential to reach a good level of Quality of Life and satisfaction of the patient. PMID:27104332

  2. Scaphoid morphology and clinical outcomes in scaphoid reconstructions.

    PubMed

    Megerle, K; Harenberg, P S; Germann, G; Hellmich, S

    2012-03-01

    Scaphoid malunion and carpal malalignment can result after scaphoid reconstruction, if the two fragments are not properly reduced before fixation. However, currently there is no information about which degree of deformity or malalignment can be tolerated without impairing clinical function. The purpose of this study was to investigate the influence of the scaphoid morphology and carpal alignment on clinical outcomes after scaphoid reconstruction. A total of 65 patients with an average age of 29 years were followed-up after a mean period of 45 months. In all patients, osseous union after a first-time scaphoid reconstruction in the middle third had been confirmed. Scapholunate (SL) and radiolunate (RL) angles were obtained on plain radiographs as were intrascaphoid (ISA) and dorsal cortical (DCA) angles and the height/length (H/L) ratio of the reconstructed scaphoid on computed tomography (CT) scans. These parameters were correlated with clinical outcome measures. RL angles correlated significantly with wrist range of motion, grip strength and pain levels, whilst SL angles, ISA, DCA and H/L ratio failed to show significant correlations. Our data suggest that clinical outcome is correlated with correct restoration of bone morphology and carpal alignment. After reconstruction, the RL angle should not exceed 10°. PMID:21903213

  3. Morphological and morphometric features of scaphoid bone in north eastern population, India.

    PubMed

    Purushothama, C; Sarda, R K; Konuri, A; Tamang, B K; Gupta, C; Murlimanju, B V

    2011-03-01

    A study was performed to analyse the morphometry and morphological variants of adult scaphoid bone in Sikkimese population of North Eastern India. The study included 100 dry human scaphoid bones. The bones which had previous signs of fracture were excluded. The morphometric parameters were measured with vernier caliper of 0.02 mm accuracy; the circumferences were measured by placing a thread around them and measuring its length. A magnifying lens was used to observe the number of foramina. From our observations, 22 (44%) of the left scaphoid were having conical shape and 28 (56%) were pyramidal in shape. On the right side, 36 (72%) had conical shape and 14 (28%) were pyramidal. All the bones had waist, except one right sided scaphoid (2%) in which the waist was absent. The scaphoid had main dorsal sulcus in 63% of cases, 29% had two dorsal sulci and 6% had Y shaped sulci. The dorsal sulcus was absent in 3 cases (1 on left side and 2 on the right side). All the scaphoids had a minimum of one foramen in the main dorsal sulcus and 92% had more than one foramen. The present study has provided the additional information on morphology and morphometry of adult human scaphoid bones in north eastern population, India. We believe that the data obtained from the present study are important for the hand surgeons and radiologists. The details obtained will also be helpful for the morphologists and clinical anatomists. PMID:21991695

  4. [Classification, significance and sequelae of posttraumatic "occult" bone and cartilage fractures of the knee. The role of magnetic resonance].

    PubMed

    Macarini, L; Zaccheo, N; Garribba, A P; Angelelli, G; Rotondo, A

    1995-12-01

    Magnetic Resonance Imaging (MRI) shows, in the post-traumatic knee, a fairly high number of bone and cartilage injuries missed by conventional radiography and therefore called occult. Our aim is to classify these injuries, to correlate their site and distribution with associated menisco-ligamentous injuries and with trauma mechanisms. Thirty-eight patients with a history of acute knee trauma and negative X-ray findings were examined with MRI within 15 days of trauma. 1.5- and 0.5-T units and SE T1-weighted GE T2*-weighted and SE T2-weighted sequences were used. The injuries were classified as intraosseous and osteochondral bruises or fractures. Twenty-three patients with menisco-ligamentous injuries were submitted to therapeutic arthroscopy; the sites of bone and cartilage injuries depicted with MRI were studied with arthroscopy. Seven patients were followed-up with MRI at 6-12 months to investigate subchondral injury evolution: 5 of 7 patients were also submitted to arthroscopy. MRI showed a statistically significant correlation between site and distribution of bone and cartilage injuries and between internal derangement and trauma mechanisms, i.e., contusion, distortion, stress. In our experience, MRI could identify and characterize occult subchondral injuries, thus allowing appropriate treatment. PMID:8685452

  5. PSEUDARTHROSIS OF THE TUBERCLE OF THE SCAPHOID BONE IN IMMATURE SKELETON: CASE REPORT

    PubMed Central

    Gomes, Eduardo Amarai; Armanelli, Felipe; Saliba, Gustavo Augusto Matos

    2015-01-01

    The aim of this study was to present a case report on pseudarthrosis of the scaphoid tubercle, a pathological condition that affects the young and active population. This entity often develops as a result of failure to make an early diagnosis and a late start to treatment. This report describes the case of a 15-year-old patient with a history of a neglected fracture of the scaphoid tubercle that occurred one year earlier and evolved to pseudarthrosis of the tubercle, which is an unusual location for this type of complication. The diagnosis was made from the clinical history and radiographic examination. The treatment was undertaken in accordance with the Matti-Russe technique, by means of a volar route, thus avoiding injury to the scaphoid vascularization, with good clinical and radiographic evolution. Pseudarthrosis of the scaphoid tubercle is a rare condition resulting from a fracture in an unusual location in the scaphoid bone, and it is important because it affects the young and active population. The correct diagnosis is only rarely made by radiologists or surgeons at the time of the fracture, because of failure to recognize this entity. This mistake delays and causes difficulty in treatments for the complications resulting from this kind of fracture. Therefore, it is essential to include this condition in differential diagnoses in order to avoid mistaken conduct. The treatment chosen was shown to be an effective option in this specific case. PMID:27047860

  6. Titanium template for scaphoid reconstruction.

    PubMed

    Haefeli, M; Schaefer, D J; Schumacher, R; Müller-Gerbl, M; Honigmann, P

    2015-06-01

    Reconstruction of a non-united scaphoid with a humpback deformity involves resection of the non-union followed by bone grafting and fixation of the fragments. Intraoperative control of the reconstruction is difficult owing to the complex three-dimensional shape of the scaphoid and the other carpal bones overlying the scaphoid on lateral radiographs. We developed a titanium template that fits exactly to the surfaces of the proximal and distal scaphoid poles to define their position relative to each other after resection of the non-union. The templates were designed on three-dimensional computed tomography reconstructions and manufactured using selective laser melting technology. Ten conserved human wrists were used to simulate the reconstruction. The achieved precision measured as the deviation of the surface of the reconstructed scaphoid from its virtual counterpart was good in five cases (maximal difference 1.5 mm), moderate in one case (maximal difference 3 mm) and inadequate in four cases (difference more than 3 mm). The main problems were attributed to the template design and can be avoided by improved pre-operative planning, as shown in a clinical case. PMID:25167978

  7. Characterization of a Pre-Clinical Mini-Pig Model of Scaphoid Non-Union.

    PubMed

    Behrends, Dominique Andre; Khendek, Leticia; Gao, Chan; Zayed, Nadia; Henderson, Janet Elizabeth; Martineau, Paul Andre

    2015-01-01

    A fractured scaphoid is a common disabling injury that is frequently complicated by non-union. The treatment of non-union remains challenging because of the scaphoid's small size and delicate blood supply. Large animal models are the most reliable method to evaluate the efficacy of new treatment modalities before their translation into clinical practice. The goal of this study was to model a human scaphoid fracture complicated by non-union in Yucatan mini-pigs. Imaging and perfusion studies were used to confirm that the anatomy and blood supply of the radiocarpal bone in mini-pigs were similar to the human scaphoid. A 3 mm osteotomy of the radiocarpal bone was generated and treated with immediate fixation or filled with a dense collagen gel followed by delayed fixation. Bone healing was assessed using quantitative micro computed tomography and histology. With immediate fixation, the osteotomy site was filled with new bone across its whole length resulting in complete bridging. The dense collagen gel, previously shown to impede neo-vascularization, followed by delayed fixation resulted in impaired bridging with less bone of lower quality. This model is an appropriate, easily reproducible model for the evaluation of novel approaches for the repair of human scaphoid fractures. PMID:26086923

  8. A qualitative evaluation of scaphoid remodeling in bone-grafted scaphoid nonunions.

    PubMed

    Grewal, Ruby; Boyd, Kirsty U; Macdermid, Joy; McMurtry, Robert Y

    2010-12-01

    The purpose of this case series is to identify and illustrate the phenomenon of scaphoid remodeling in skeletally mature subjects following bone grafting for scaphoid nonunion. Nine patients with scaphoid nonunions were treated with interpositional bone grafting (with iliac crest bone graft) and K-wire fixation. The mean length of follow-up was 28.6 ± 9 months. Radiographs and CT scans were reviewed and assessed for degree of union and a qualitative assessment of scaphoid architecture. Following surgery, there was marked distortion of the scaphoid. Once healed, the contour of the scaphoid was still significantly distorted in all nine patients. Remodeling then became evident along the articular surfaces between 8 and 12 months. By 3 years, the scaphoid was completely recontoured and the normal architecture was completely restored in all nine patients. We conclude that the articular surface of the scaphoid remodels over time in skeletally mature subjects. PMID:22131928

  9. Atraumatic Occult Odontoid Fracture in Patients with Osteoporosis-Associated Thoracic Kyphotic Deformity: Report of a Case and Review of the Literature.

    PubMed

    Mori, Kanji; Nishizawa, Kazuya; Nakamura, Akira; Imai, Shinji

    2015-01-01

    Anderson type II odontoid fractures are reported to be the most common injury of the odontoid process in patients over the age of 65. However, atraumatic occult Anderson type III odontoid fractures have been rarely described and remain a diagnostic challenge. In the present report, we illustrate a 78-year-old female with osteoporosis-associated marked thoracic kyphotic deformity who developed atraumatic Anderson type III occult odontoid fracture and raise awareness of this condition. Anteroposterior and lateral standard radiographs of cervical spine failed to disclose odontoid fracture. Magnetic resonance imaging demonstrated intensity changes of the axis. Subsequent computed tomography clearly demonstrated Anderson type III odontoid fracture. Conservative treatment achieved complete bone union without neurological deteriorations. At 3-year follow-up, the patient was doing well without neurological and radiological deteriorations. Even if the patients have no traumatic event, we have to keep odontoid fractures in our mind as one of the differential diagnoses when we encounter elderly patients with neck pain, especially in patients with osteoporosis-associated marked thoracic kyphotic deformity. PMID:26380137

  10. Atraumatic Occult Odontoid Fracture in Patients with Osteoporosis-Associated Thoracic Kyphotic Deformity: Report of a Case and Review of the Literature

    PubMed Central

    Mori, Kanji; Nishizawa, Kazuya; Nakamura, Akira; Imai, Shinji

    2015-01-01

    Anderson type II odontoid fractures are reported to be the most common injury of the odontoid process in patients over the age of 65. However, atraumatic occult Anderson type III odontoid fractures have been rarely described and remain a diagnostic challenge. In the present report, we illustrate a 78-year-old female with osteoporosis-associated marked thoracic kyphotic deformity who developed atraumatic Anderson type III occult odontoid fracture and raise awareness of this condition. Anteroposterior and lateral standard radiographs of cervical spine failed to disclose odontoid fracture. Magnetic resonance imaging demonstrated intensity changes of the axis. Subsequent computed tomography clearly demonstrated Anderson type III odontoid fracture. Conservative treatment achieved complete bone union without neurological deteriorations. At 3-year follow-up, the patient was doing well without neurological and radiological deteriorations. Even if the patients have no traumatic event, we have to keep odontoid fractures in our mind as one of the differential diagnoses when we encounter elderly patients with neck pain, especially in patients with osteoporosis-associated marked thoracic kyphotic deformity. PMID:26380137

  11. Kinematics of the scaphoid shift test.

    PubMed

    Wolfe, S W; Gupta, A; Crisco, J J

    1997-09-01

    Twenty-five uninjured subjects (50 wrists) were examined clinically and fluoroscopically during performance of the scaphoid shift test. Wrists were placed into 3 groups on the basis of the degree of palpable carpal motion that occurred during the clinical examination. Kinematic parameters of rotation and displacement were calculated from digitized images of the carpals at rest and at maximum displacement. On clinical exam, 36% of normal individuals had positive findings on scaphoid shift test. Dorsal displacement of the scaphoid was not significantly associated with positive scaphoid shift test results in these subjects, while total displacement of the scaphoid (the sum of axial and dorsal displacement) was significantly associated with positive test results. The principle confounding factor appeared to be a high degree of displacement that occurred at the capitolunate joint in some individuals, termed a "midcarpal shift." The data demonstrate that despite a high prevalence of positive scaphoid shifts among uninjured individuals, the ability to accurately detect dorsal displacement of the scaphoid using the scaphoid shift test is limited. On the basis of their findings, the authors recommend that positive test results be confirmed fluoroscopically. PMID:9330136

  12. Characterization of a Pre-Clinical Mini-Pig Model of Scaphoid Non-Union

    PubMed Central

    Behrends, Dominique Andre; Khendek, Leticia; Gao, Chan; Zayed, Nadia; Henderson, Janet Elizabeth; Martineau, Paul Andre

    2015-01-01

    A fractured scaphoid is a common disabling injury that is frequently complicated by non-union. The treatment of non-union remains challenging because of the scaphoid’s small size and delicate blood supply. Large animal models are the most reliable method to evaluate the efficacy of new treatment modalities before their translation into clinical practice. The goal of this study was to model a human scaphoid fracture complicated by non-union in Yucatan mini-pigs. Imaging and perfusion studies were used to confirm that the anatomy and blood supply of the radiocarpal bone in mini-pigs were similar to the human scaphoid. A 3 mm osteotomy of the radiocarpal bone was generated and treated with immediate fixation or filled with a dense collagen gel followed by delayed fixation. Bone healing was assessed using quantitative micro computed tomography and histology. With immediate fixation, the osteotomy site was filled with new bone across its whole length resulting in complete bridging. The dense collagen gel, previously shown to impede neo-vascularization, followed by delayed fixation resulted in impaired bridging with less bone of lower quality. This model is an appropriate, easily reproducible model for the evaluation of novel approaches for the repair of human scaphoid fractures. PMID:26086923

  13. [Scaphoid percutaneous osteosynthesis by screw using computer assisted surgery: an experimental study].

    PubMed

    Liverneaux, P

    2005-01-01

    Scaphoid fractures are sometimes difficult to diagnose and even more difficult to fix. Recent progress such as miniaturization of osteosynthesis material, adoption of the percutaneous route, and widening of the indications to include undisplaced fractures has still not abolished complications. In this context, computer assisted surgery (CAS) may be useful and deserves further study. To apply it to the scaphoid, it is initially necessary to immobilize the "wrist hand fingers" unit in a device adapted to make it a rigid unit. It is then necessary to choose the correct configuration of CAS system. The pedicular fluoroscopic navigation system, which is apparently similar to scaphoid screw insertion, was chosen for this study. The goal of this study is to define the osteosynthesis bases of the scaphoid with CAS. A fresh anatomical subject divided at the elbow joint was prepared at the DETERCA laboratory of the university Bordeaux 2. The solid "wrist hand fingers" unit was immobilized in extension and ulnar deviation of the wrist by a malleable, stable and radio transparent device. The first stage consisted of a calibration of the surgical instruments and the "wrist hand fingers" unit, with a three-dimensional optical localization system. The guide wire was simulated by a gauged stylet. When the axis and the length of the screw had been determined virtually, insertion of the guide wire was carried out under guidance of the virtual images of the computer's screen, without the assistance of the fluoroscopy. Finally the canulated screw was inserted over the guide wire. Insertion was stopped when the screw reached the intra osseous virtually predetermined length. A check using conventional fluoroscopy made it possible to ensure the correct positioning of the screw. Our results show that it is possible to insert a screw into a scaphoid without conventional fluoroscopy, by using the fluoroscopic navigation system. The procedure was performed without difficulty, apart from the

  14. An unusual variant of perilunate fracture dislocations.

    PubMed

    Morin, Matthew L; Becker, Giles W

    2016-01-01

    Trans-scaphoid, trans-radial styloid, trans-triquetral perilunate fracture dislocations are rare. We describe a 19-year-old male who suffered this injury after crashing his bicycle. He underwent open reduction internal fixation and percutaneous pinning. Scaphoid union was achieved at 8 weeks. Near complete range of painless motion was achieved by 4 months. PMID:27583261

  15. An unusual variant of perilunate fracture dislocations

    PubMed Central

    Morin, Matthew L.; Becker, Giles W.

    2016-01-01

    Abstract Trans-scaphoid, trans-radial styloid, trans-triquetral perilunate fracture dislocations are rare. We describe a 19-year-old male who suffered this injury after crashing his bicycle. He underwent open reduction internal fixation and percutaneous pinning. Scaphoid union was achieved at 8 weeks. Near complete range of painless motion was achieved by 4 months.

  16. Enchondroma of the scaphoid: a case report

    PubMed Central

    Ali, Sbai Mohamed; Sofien, Benzarti; Feten, Sbei; Khaled, Bouzaidi; Riadh, Maalla

    2015-01-01

    Enchondroma represents a common bone tumor of the hand. The scaphoid is a rare location. We report the case of a scaphoid enchondroma presenting as chronic wrist pain following a relatively minor trauma. The diagnosis was suggested by radiological study and then confirmed by histological study after biopsy. Enucleation and vascularized bone graft with osteosynthesis provided good results. The clinical, radiological and therapeutic aspects of this rare condition are discussed. PMID:26327970

  17. Enchondroma of the scaphoid: a case report.

    PubMed

    Ali, Sbai Mohamed; Sofien, Benzarti; Feten, Sbei; Khaled, Bouzaidi; Riadh, Maalla

    2015-01-01

    Enchondroma represents a common bone tumor of the hand. The scaphoid is a rare location. We report the case of a scaphoid enchondroma presenting as chronic wrist pain following a relatively minor trauma. The diagnosis was suggested by radiological study and then confirmed by histological study after biopsy. Enucleation and vascularized bone graft with osteosynthesis provided good results. The clinical, radiological and therapeutic aspects of this rare condition are discussed. PMID:26327970

  18. OSTEOID OSTEOMA IN SCAPHOID: CASE REPORT

    PubMed Central

    Severo, Antônio Lourenço; de Araújo Filho, Raimundo; Puentes, Rulby; Lemos, Marcelo Barreto; Piluski, Paulo Faiad; Lech, Osvandré

    2015-01-01

    Osteoid osteoma is a benign osteoblastic tumor that is unusual in the hand. A location in the carpal bones is infrequent, which leads to errors in diagnosing it because of polymorphism of the clinical symptoms. Reviewing the literature shows that nine cases of osteoid osteoma in the scaphoid have been reported. Here, one case of osteoid osteoma in the scaphoid that was initially treated as De Quervain's stenosing tenosynovitis is reported, with a definitive diagnosis that was delayed for five years. PMID:27047881

  19. OSTEOID OSTEOMA IN SCAPHOID: CASE REPORT.

    PubMed

    Severo, Antônio Lourenço; de Araújo Filho, Raimundo; Puentes, Rulby; Lemos, Marcelo Barreto; Piluski, Paulo Faiad; Lech, Osvandré

    2012-01-01

    Osteoid osteoma is a benign osteoblastic tumor that is unusual in the hand. A location in the carpal bones is infrequent, which leads to errors in diagnosing it because of polymorphism of the clinical symptoms. Reviewing the literature shows that nine cases of osteoid osteoma in the scaphoid have been reported. Here, one case of osteoid osteoma in the scaphoid that was initially treated as De Quervain's stenosing tenosynovitis is reported, with a definitive diagnosis that was delayed for five years. PMID:27047881

  20. A new variant of scaphoid reconstruction: Treatment of scaphoid non-union with avascular bone interponate and high compression screw (Synthes(®)).

    PubMed

    Eder, Christian; Schwab, Nina; Scheller, Ariane; Krapohl, Björn Dirk

    2015-01-01

    Scaphoid fractures as frequently overseen injuries often result in scaphoid non-unions, that need to be treated to prevent carpal collapse and secondary cartilage damage. Vital bone tissue and compression of fracture and bone graft ends seem to be crucial in for ossification and final bone healing. In the present study we compare our results using a high compression screw (HCS Synthes(®)) to results in the literature using different kinds of internal fixation including compression screws of various types. We present 22 patients with scaphoid non-unions treated with a bone graft and a HCS Synthes(®). We evaluated our post-operative results. The Manchester-Modified Disability of the Shoulder, Arm and Hand-Score (M-Dash) imposed with an average of 29.8 points (MD=29 / SD=9.46 / MIN=18 / MAX=48). None of the re-evaluated patients sorrowed for pain in rest. Five patients stated pain (ranging from 4 to 8 on numeric analogue scale) after heavy burden (e.g. boxing, weight lifting).In exploring the range of motion of the operated hand we deliver the following results: dorsal extension: average 72.73° (MD=80° / SD=17.23° / MIN=30° / MAX=85°), flexion: average 73.64° (MD=80° / SD=8.97° / MIN=60° / MAX=80°), ulnar deviation: average 39.09°, (MD=40° / SD=2.02° / MIN=35° / MAX=40°), radial deviation: average 29.09°, (MD=30° / SD=3.01° / MIN=20° / MAX=30°). Additionally a performance testing was conducted: fist clenching sign: complete without pain in 100%, pinch grip: complete in 100%, moderate pain in n=1 (8.33%), opposition digitus manus I-V complete in 100%, moderate pain n=2 (16.67%). Three patients with persisting fracture gap had a scaphoid bone fractured in the proximal third; one patient even with a very small proximal fragment. One persisting non-union was localized in the middle third (period between injury and operation = 5 years). In conclusion, our patients showed better healing rates compared to results presented in the literature. Non

  1. A new variant of scaphoid reconstruction: Treatment of scaphoid non-union with avascular bone interponate and high compression screw (Synthes®)

    PubMed Central

    Eder, Christian; Schwab, Nina; Scheller, Ariane; Krapohl, Björn Dirk

    2015-01-01

    Scaphoid fractures as frequently overseen injuries often result in scaphoid non-unions, that need to be treated to prevent carpal collapse and secondary cartilage damage. Vital bone tissue and compression of fracture and bone graft ends seem to be crucial in for ossification and final bone healing. In the present study we compare our results using a high compression screw (HCS Synthes®) to results in the literature using different kinds of internal fixation including compression screws of various types. We present 22 patients with scaphoid non-unions treated with a bone graft and a HCS Synthes®. We evaluated our post-operative results. The Manchester-Modified Disability of the Shoulder, Arm and Hand–Score (M-Dash) imposed with an average of 29.8 points (MD=29 / SD=9.46 / MIN=18 / MAX=48). None of the re-evaluated patients sorrowed for pain in rest. Five patients stated pain (ranging from 4 to 8 on numeric analogue scale) after heavy burden (e.g. boxing, weight lifting).In exploring the range of motion of the operated hand we deliver the following results: dorsal extension: average 72.73° (MD=80° / SD=17.23° / MIN=30° / MAX=85°), flexion: average 73.64° (MD=80° / SD=8.97° / MIN=60° / MAX=80°), ulnar deviation: average 39.09°, (MD=40° / SD=2.02° / MIN=35° / MAX=40°), radial deviation: average 29.09°, (MD=30° / SD=3.01° / MIN=20° / MAX=30°). Additionally a performance testing was conducted: fist clenching sign: complete without pain in 100%, pinch grip: complete in 100%, moderate pain in n=1 (8.33%), opposition digitus manus I–V complete in 100%, moderate pain n=2 (16.67%). Three patients with persisting fracture gap had a scaphoid bone fractured in the proximal third; one patient even with a very small proximal fragment. One persisting non-union was localized in the middle third (period between injury and operation = 5 years). In conclusion, our patients showed better healing rates compared to results presented in the literature. Non

  2. The use of the free vascularised bone graft for nonunion of the scaphoid: a systematic review

    PubMed Central

    2014-01-01

    Background Fractures of the scaphoid are well known to be problematic especially when complicated by avascular necrosis, nonunion and carpal collapse. Fixation techniques have involved nonvascularised bone grafting; however, in the presence of avascular necrosis, generally poor union rates (47%) occur as identified by a meta-analysis performed by Merrell et al. The introduction of pedicled vascularised bone grafts showed further improvement; however, in the presence of carpal collapse, union rates as low as 50% have been reported by Chang et al. amongst others using the 1,2-intercompartmental supraretinacular artery pedicled graft. The difficulty lies in having a short pedicle with limited manoeuvrability to correct a humpback deformity and insert into the scaphoid cavity. Prior trauma to the soft tissues or distal radius may prohibit the use of pedicled grafts. The aim of this systematic review is to examine the published evidence for the use of free vascularised bone grafts in cases of scaphoid nonunion. Methods A systematic review was performed with the following defined search strategy on MEDLINE and Google Scholar: ((scaphoid nonunion) OR scaphoid pseudarthrosis) AND bone graft. Articles were reviewed and data compiled into tables for analysis. Statistical analysis was performed with determination of descriptive statistics, and differences between the groups were calculated using categorical variables and chi-square test. A p value of 0.05 or less was considered to be statistically significant. Results Two hundred and sixty-three articles were identified with a total of 12 articles meeting the inclusion criteria. Two hundred and forty-five cases of scaphoid nonunion were identified through the articles included in this systematic review. Fifty-six patients underwent free vascularised bone grafts from the medial femoral condyle with a 100% union rate and correction of humpback deformity, and 188 patients underwent free vascularised bone grafting from the iliac

  3. Comparison of 2D and 3D navigation techniques for percutaneous screw insertion into the scaphoid: results of an experimental cadaver study.

    PubMed

    Catala-Lehnen, Philip; Nüchtern, Jakob V; Briem, Daniel; Klink, Thorsten; Rueger, Johannes M; Lehmann, Wolfgang

    2011-01-01

    Navigation in hand surgery is still in the process of development. Initial studies have demonstrated the feasibility of 2D and 3D navigation for the palmar approach in scaphoid fractures, but a comparison of the possibilities of 2D and 3D navigation for the dorsal approach is still lacking. The aim of the present work was to test navigation for the dorsal approach in the scaphoid using cadaver bones. After development of a special radiolucent resting splint for the dorsal approach, we performed 2D- and 3D-navigated scaphoid osteosynthesis in 12 fresh-frozen cadaver forearms using a headless compression screw (Synthes). The operation time, radiation time, number of trials for screw insertion, and screw positions were analyzed. In six 2D-navigated screw osteosyntheses, we found two false positions with an average radiation time of 5 ± 2 seconds. Using 3D navigation, we detected one false position. A false position indicates divergence from the ideal line of the axis of the scaphoid but without penetration of the cortex. The initial scan clearly increased overall radiation time in the 3D-navigated group, and for both navigation procedures operating time was longer than in our clinical experience without navigation. Nonetheless, 2D and 3D navigation for non-dislocated scaphoid fractures is feasible, and navigation might reduce the risk of choosing an incorrect screw length, thereby possibly avoiding injury to the subtending cortex. The 3D navigation is more difficult to interpret than 2D fluoroscopic navigation but shows greater precision. Overall, navigation is costly, and the moderate advantages it offers for osteosynthesis of scaphoid fractures must be considered critically in comparisons with conventional operating techniques. PMID:21991920

  4. Corrective osteotomy for symptomatic scaphoid malunion.

    PubMed

    El-Karef, Essam Awad

    2005-12-01

    A prospective study aimed at assessment of the outcome of management of symptomatic scaphoid malunion (hump-back deformity). The work included 13 scaphoid malunions in 13 patients. All patients complained of weak painful hand grip and limitation of wrist function. All cases were subjected to a corrective opening wedge scaphoid osteotomy with insertion of a trapezoid-shaped tricortical iliac bone graft. At the final assessment, after a mean follow-up period of 42 months, the achieved results were rated excellent in seven cases, good in four and fair in two according to the scoring system used. Objectively, the mean range of wrist motion and hand grip strength improved from 48% and 47% pre-operatively to 82% and 79% at the final assessment. Radiological parameters including height to length ratio, lateral intrascaphoid angle and dorsal cortical angle were also effectively improved. The intra-operative corrected carpal alignment has almost been maintained at the final follow-up. The procedure did not have serious drawbacks such as non-union or avascular necrosis and perhaps might delay the development of degenerative arthritis of the wrist. PMID:16256995

  5. Avascular necrosis of the distal pole of the scaphoid

    PubMed Central

    Tokyay, Abbas; Gunal, Izge

    2015-01-01

    Abstract Avascular necrosis (AVN) of the scaphoid predominantly occurs in the proximal pole. Review of the literature revealed only six cases and all are suspect due to the lack of either MRI investigation or investigation of bleeding preoperatively. We report four new cases and one of them appears to be a real distal pole AVN of the scaphoid in the literature.

  6. The Role of Dynamic Contrast-Enhanced MRI in a Child with Sport-Induced Avascular Necrosis of the Scaphoid: A Case Report and Literature Review

    PubMed Central

    Jong, Bob; Tilman, Pieter

    2016-01-01

    Avascular necrosis (AVN) of the scaphoid in children is very rare and there is currently no consensus when conservative or operative treatment is indicated. A 10-year-old boy, practicing karate, presented with acute pain in his left wrist after falling on the outstretched hand. Imaging showed a scaphoid waist fracture with signs of an ongoing AVN. The diagnosis of AVN was confirmed with signal loss of the scaphoid on MRI T1. A dynamic contrast-enhanced MRI was performed for further assessment of the proximal pole vascularity and treatment planning. As dynamic contrast-enhanced MRI showed fair perfusion of the proximal pole, an adequate healing potential with conservative treatment was estimated. We achieved union and good function with cast immobilization for fourteen weeks. This case study showed dynamic contrast-enhanced MRI to be a valuable tool in assessing whether conservative or operative treatment is indicated to achieve union and good functional outcome. PMID:27529045

  7. [Treatment of pseudoarthrosis of the carpal scaphoid with fibrin glue].

    PubMed

    Carozzi, S

    1983-08-01

    The author think that "Fibrin Seal Glue" and mechanical syntesis is an opimal method for osteosintesis of the Carpal scaphoid. He speaks about 5 patients treated with optimal results in 50 days mean. PMID:6395974

  8. Occult scapholunate ganglion: a cause of dorsal radial wrist pain.

    PubMed

    Steinberg, B D; Kleinman, W B

    1999-03-01

    There are multiple causes for chronic dorsal wrist pain over the scapholunate ligament, including occult dorsal carpal ganglion cyst, scaphoid impaction syndrome, dorsal carpal capsulitis, distal posterior interosseous nerve syndrome, and dynamic scapholunate ligament instability. Patients with such pain often have normal x-rays. A retrospective study of 21 patients undergoing surgical exploration for chronic dorsal radial wrist pain who had no palpable cyst and normal x-rays revealed that 18 of the patients had occult scapholunate ganglion cysts or myxomatous degeneration within the scapholunate ligament. All had failed long-term conservative management. Surgery involved an approach through Langer's lines, resection of a large triangular portion of the capsule between the dorsal intercarpal and radiotriquetral ligaments, and tangential debridement of the area of myxoid degeneration proximal to the distal 2 to 3 mm of dorsal scapholunate interosseous ligament. None of the patients had scapholunate instability or scaphoid impacting syndrome. Of the 18 patients with histologically confirmed myxomatous changes in the scapholunate ligament, 16 had an excellent outcome as defined by rigorous criteria; 1 had a good outcome. There was 1 patient with a poor result. A compelling argument is made for surgical exploration of the scapholunate joint in patients with persistent dorsal radial wrist pain and scapholunate point tenderness. PMID:10194003

  9. Correlation of Reconstructed Scaphoid Morphology with Clinical Outcomes

    PubMed Central

    Afshar, Ahmadreza; Mohammadi, Afshin; Zohrabi, Kian; Navaeifar, Nasrin; Sami, Sam H.; Taleb, Hassan

    2015-01-01

    Background: Scaphoid malunion alters the carpal kinematics and impairs clinical outcome because of pain, weakness, restricted range of motion and predisposing the wrist joint to early osteoarthritis. The aim of this study was to evaluate the influence of the scaphoid morphological angles on clinical outcomes in patients with reconstructed scaphoid by non-vascularized bone graft. Methods: Seventeen male patients with the mean age of 31.7±3.7 years and mean non-union time of 31.5±14.7 months were enrolled in this retrospective study. Average follow up was 48.8±9.4 months. At the last follow-up, the patients were evaluated clinically for pain, wrist range of motion, grip strength, and wrist functional status. They were also evaluated radiologically by wrist radiographs and computerized tomography (CT). The overall clinical outcomes were evaluated by the Cooney wrist function score. The morphology of the reconstructed scaphoids was evaluated by the lateral intrascaphoid angle, antroposterior intrascaphoid angle, dorsal cortical angle, measuring the length (mm), and height-to-length ratio on CT scan. The radiological measurements were compared against the overall clinical outcomes. Results: There were 7 excellent, 7 good, 3 fair clinical results. The mean Cooney wrist function score was 83±4. The mean lateral intrascaphoid angle was 34.8±1.4 degrees, mean antroposterior intrascaphoid angle was 33.4±2.2 degrees, mean dorsal cortical angle was 158.3±4.8 degrees, mean scaphoid length was 22.1± 0.7 mm, and mean scaphoid height-to-length ratio was 0.74±0.04. There were no significant statistical correlations between the lateral intrascaphoid angles, antroposterior intrascaphoid angles, dorsal cortical angles, scaphoid lengths and scaphoid height-to-length ratios and Cooney wrist scores in the patients. Conclusion: In the current study, all the patients had some degree of scaphoid malunion; however, the radiological measurements of the reconstructed scaphoids did not

  10. 21 CFR 888.3760 - Wrist joint carpal scaphoid polymer prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Wrist joint carpal scaphoid polymer prosthesis. 888.3760 Section 888.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... scaphoid polymer prosthesis. (a) Identification. A wrist joint carpal scaphoid polymer prosthesis is a...

  11. 21 CFR 888.3760 - Wrist joint carpal scaphoid polymer prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Wrist joint carpal scaphoid polymer prosthesis. 888.3760 Section 888.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... scaphoid polymer prosthesis. (a) Identification. A wrist joint carpal scaphoid polymer prosthesis is a...

  12. 21 CFR 888.3760 - Wrist joint carpal scaphoid polymer prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Wrist joint carpal scaphoid polymer prosthesis. 888.3760 Section 888.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... scaphoid polymer prosthesis. (a) Identification. A wrist joint carpal scaphoid polymer prosthesis is a...

  13. 21 CFR 888.3760 - Wrist joint carpal scaphoid polymer prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Wrist joint carpal scaphoid polymer prosthesis. 888.3760 Section 888.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... scaphoid polymer prosthesis. (a) Identification. A wrist joint carpal scaphoid polymer prosthesis is a...

  14. 21 CFR 888.3760 - Wrist joint carpal scaphoid polymer prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Wrist joint carpal scaphoid polymer prosthesis. 888.3760 Section 888.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... scaphoid polymer prosthesis. (a) Identification. A wrist joint carpal scaphoid polymer prosthesis is a...

  15. Biomechanical Evaluation of Ligamentous Stabilizers of the Scaphoid and Lunate

    PubMed Central

    Short, Walter H.; Werner, Frederick W.; Green, Jason K.; Masaoka, Shunji

    2007-01-01

    This study evaluated the effects of sectioning the scapholunate interosseous ligament, radioscaphocapitate ligament, and scaphotrapezial ligament on the kinematics of the scaphoid and lunate. Eight cadaver upper extremities were placed in a wrist joint simulator and moved in continuous cycles of flexion-extension and radial-ulnar deviation. Positional data of the scaphoid and lunate were obtained in the intact state, after the scapholunate ligament was cut; after the scapholunate and scaphotrapezial ligaments were cut; after the scapholunate, scaphotrapezial, and radioscaphocapitate ligaments were cut; and after all 3 ligaments were cut and the specimen was placed through an additional 1,000 cycles of flexion-extension. Cutting the scapholunate ligament caused changes in scaphoid and lunate motion during flexion-extension, but not radial-ulnar deviation. Additional sectioning of the scaphotrapezial ligament followed by the radioscaphocapitate ligament caused further kinematic changes in these carpal bones. One thousand cycles of motion after all 3 ligaments were sectioned caused additional kinematic changes in the scaphoid and lunate. The scapholunate ligament appears to be the primary stabilizer between the scaphoid and lunate. The radioscaphocapitate and scaphotrapezial ligaments are secondary restraints. Repetitive cyclic motion after ligament sectioning appears to have additional deleterious effects on carpal kinematics. PMID:12457349

  16. The Occult Today: Why?

    ERIC Educational Resources Information Center

    Kessler, Gary E.

    1975-01-01

    Author offered some reflections on the "why" of the contemporary interest in the occult. He attempted to convince the reader that, if he or she has been surprised by the recent rise of occultism, sober reflection will dispell some fears and, perhaps, even convince him or her that occultism is not merely superstition. (Author/RK)

  17. The factors affecting outcome after non-vascular bone grafting and internal fixation for nonunion of the scaphoid.

    PubMed

    Ramamurthy, C; Cutler, L; Nuttall, D; Simison, A J M; Trail, I A; Stanley, J K

    2007-05-01

    This study identified variables which influence the outcome of surgical management on 126 ununited scaphoid fractures managed by internal fixation and non-vascular bone grafting. The site of fracture was defined by a new method: the ratio of the length of the proximal fragment to the sum of the lengths of both fragments, calculated using specific views in the plain radiographs. Bone healing occurred in 71% (89) of cases. Only the site of nonunion (p = 1 x 10(-6)) and the delay to surgery (p = 0.001) remained significant on multivariate analysis. The effect of surgical delay on the probability of union increased as the fracture site moved proximally. A prediction model was produced by stepwise logistic regression analysis, enabling the surgeon to predict the success of surgery where the site of the nonunion and delay to surgery is known. PMID:17540748

  18. Studies in occultation astronomy

    NASA Technical Reports Server (NTRS)

    Veverka, J.

    1980-01-01

    Major scientific results are summarized for the following studies: (1) observations of the 8 April 1976 occultation of epsilon Geminorum by Mars; (2) studies in occultation techniques; and (3) the March 1974 occultation of Saturn by the Moon. A re-analysis of the 1974 lunar occultation of the Titan indicates that Titan is strongly limb darkened, with D approximately greater than 5800km; there is internal evidence in the data that Titan's atmosphere is inhomogeneous; and that observations are inconsistent with any sample homogeneous model atmosphere which matches the P (lambda) and Beta (lambda) observations of Titan.

  19. Deep shadow occulter

    NASA Technical Reports Server (NTRS)

    Cash, Webster (Inventor)

    2010-01-01

    Methods and apparatus are disclosed for occulting light. The occulter shape suppresses diffraction at any given size or angle and is practical to build because it can be made binary to avoid scatter. Binary structures may be fully opaque or fully transmitting at specific points. The diffraction suppression is spectrally broad so that it may be used with incoherent white light. An occulter may also include substantially opaque inner portion and an at least partially transparent outer portion. Such occulters may be used on the ground to create a deep shadow in a short distance, or may be used in space to suppress starlight and reveal exoplanets.

  20. Fractures

    PubMed Central

    Hall, Michael C.

    1963-01-01

    Recent studies on the epidemiology and repair of fractures are reviewed. The type and severity of the fracture bears a relation to the age, sex and occupation of the patient. Bone tissue after fracture shows a process of inflammation and repair common to all members of the connective tissue family, but it repairs with specific tissue. Cartilage forms when the oxygen supply is outgrown. After a fracture, the vascular bed enlarges. The major blood supply to healing tissue is from medullary vessels and destruction of them will cause necrosis of the inner two-thirds of the cortex. Callus rapidly mineralizes, but full mineralization is achieved slowly; increased mineral metabolism lasts several years after fracture. PMID:13952119

  1. Fractures

    MedlinePlus

    ... commonly happen because of car accidents, falls, or sports injuries. Other causes are low bone density and osteoporosis, which cause weakening of the bones. Overuse can cause stress fractures, which are very small cracks in the ...

  2. Fractures

    MedlinePlus

    A fracture is a break, usually in a bone. If the broken bone punctures the skin, it is called an open ... falls, or sports injuries. Other causes are low bone density and osteoporosis, which cause weakening of the ...

  3. Rotational Stability of Scaphoid Osteosyntheses: An In Vitro Comparison of Small Fragment Cannulated Screws to Novel Bone Screw Sets

    PubMed Central

    Erhart, Jochen; Unger, Ewald; Schefzig, Philip; Varga, Peter; Trulson, Inga; Gormasz, Anna; Trulson, Alexander; Reschl, Martin; Hagmann, Michael; Vecsei, Vilmos; Mayr, Winfried

    2016-01-01

    Background The current standard of care for operative repair of scaphoid fractures involves reduction and internal fixation with a single headless compression screw. However, a compression screw in isolation does not necessarily control rotational stability at a fracture or nonunion site. The single screw provides rotational control through friction and bone interdigitation from compression at the fracture site. We hypothesize that osteosyntheses with novel bone screw sets (BSS) equipped with anti-rotational elements provide improved rotational stability. Methods Stability of osteosynthesis under increasing cyclic torsional loading was investigated on osteotomized cadaveric scaphoids. Two novel prototype BSS, oblique type (BSS-obl.) and longitudinal type (BSS-long.) were compared to three conventional screws: Acutrak2®mini, HCS®3.0 and Twinfix®. Biomechanical tests were performed on scaphoids from single donors in paired comparison and analyzed by balanced incomplete random block design. Loading was increased by 50 mNm increments with 1,000 cycles per torque level and repeated until a rotational clearance of 10°. Primary outcome measure was the number of cycles to 10° clearance, secondary outcome measure was the maximum rotational clearance for each torque level. Findings BSS-obl. performed significantly better than Acutrak2®mini and HCS® (p = 0.015, p<0.0001). BSS-long. performed significantly better than HCS® (p = 0.010). No significant difference in performance between BSS-obl. and BSS-long. (p = 0.361), between BSS obl. and Twinfix® (p = 0.50) and BSS long. and Twinfix® (p = 0.667) was detected. Within the torque range up to 200 mNm, four of 21 (19%) BSS-long. and four of 21 (19%) BSS-obl. preparations showed early failure. The same loading led to early failure in four (29%) Twinfix®, seven (50%) Acutrak2®mini and 10 (71%) HCS® of 14 screw samples, respectively. Conclusions For both BSS and to a lesser extent for Twinfix® (as dual-component screw

  4. Unusual Localization of a Primary Hydatid Cyst: Scaphoid Bone

    PubMed Central

    Serbest, Sancar; Tiftikci, Ugur; Uludag, Abuzer

    2016-01-01

    Abstract Because hydatidosis of the bone (echinococcus infection) is a rare parasitic infection, its diagnosis and treatment poses great difficulties. Radiologic imaging findings are generally helpful to make the diagnosis. But occurrence of disease in atypical places and lack of specific radiological findings may complicate differential diagnosis. Nevertheless, familiarity with imaging findings in patients living at endemic areas provides advantages for diagnosis and treatment. We present a cyst hydatic case in scaphoid bone which has been reported in the literature only once previously. PMID:27124019

  5. Complete dorsal dislocation of the carpal scaphoid with perilunate dorsal dislocation

    PubMed Central

    Kang, Jong Woo; Park, Jong Hoon; Suh, Dong Hun; Park, Jong Woong

    2016-01-01

    Complete dorsal dislocation of the carpal scaphoid combined with dorsal perilunate dislocation is an extremely rare carpal injury. We describe the case of a 23-year-old man who presented with a complete dorsal dislocation of the carpal scaphoid, combined with a perilunate dislocation. Surgical treatment was performed with open reduction and interosseus ligament repair. At 4 years follow up, the patient's wrist pain had completely resolved without limitations of wrist joint motion and without evidence of avascular necrosis of the carpal scaphoid. PMID:27512229

  6. The effect of dorsal carpal ganglion excision on the scaphoid shift test.

    PubMed

    Hwang, J J; Goldfarb, C A; Gelberman, R H; Boyer, M I

    1999-02-01

    A clinical and radiographic review was performed on 18 patients (19 wrists) with dorsal carpal ganglia and associated positive scaphoid shift test. All patients underwent excision of the ganglion followed by 2 weeks of postoperative immobilization with the wrist in 20 degrees extension. All patients had wrist pain, a painful clunk on the Watson scaphoid shift test, localized tenderness on palpation of the scapholunate articulation and normal radiographs. Patients were assessed postoperatively by questionnaire and physical examination. Improved functional activity and decreased pain were noted in all patients. In 17 of 19 wrists, the positive preoperative Watson scaphoid shift test become negative. We believe that dorsal wrist ganglia are frequently associated with a positive scaphoid shift test and that excision of the ganglion followed by 2 weeks immobilization may lead to resolution of the signs and symptoms of instability, at least in the short term. PMID:10190618

  7. Occult intrasacral meningocoele

    PubMed Central

    Joseph, Roma A.; McKenzie, Thomas

    1970-01-01

    A case is reported of the rare lesion occult intrasacral meningocoele in a 27-year-old woman who developed symptoms for the first time shortly after the birth of her fourth child. The terminology of the condition is discussed and its pathogenesis, mode of presentation, and treatment reviewed. Images PMID:5528202

  8. All about Occultation.

    ERIC Educational Resources Information Center

    Riddle, Bob

    2001-01-01

    Describes occultation events involving the moon, when the moon blocks the view of planets or stars. Describes other events such as a partial solar eclipse, a penumbral lunar eclipse, meteor showers, and moon phases. Provides a list of internet resources related to these events. (DLH)

  9. The Pinhole/Occulter Facility

    NASA Technical Reports Server (NTRS)

    Tandberg-Hanssen, E. A. (Editor); Hudson, H. S. (Editor); Dabbs, J. R. (Editor); Baity, W. A. (Editor)

    1983-01-01

    Scientific objectives and requirements are discussed for solar X-ray observations, coronagraph observations, studies of coronal particle acceleration, and cosmic X-ray observations. Improved sensitivity and resolution can be provided for these studies using the pinhole/occulter facility which consists of a self-deployed boom of 50 m length separating an occulter plane from a detector plane. The X-ray detectors and coronagraphic optics mounted on the detector plane are analogous to the focal plane instrumentation of an ordinary telescope except that they use the occulter only for providing a shadow pattern. The occulter plane is passive and has no electrical interface with the rest of the facility.

  10. Evaluating degenerative changes in the wrist after surgical treatment for scaphoid pseudarthrosis using a corticocancellous graft for anatomical reconstruction.

    PubMed

    Markowicz, Agnieszka; Baczkowski, Bogusław; Lorczyński, Adam; Sawicka, Joanna; Siwicka, Karolina

    2006-10-31

    Background. Pseudoarthrosis of the scaphoid results in the development of carpal instability and severe posttraumatic osteoarthritis. Modern methods of treatment focus on reconstruction of the anatomical shape and length of the scaphoid. The purpose of our study was to determine the occurrence of carpal osteoarthritis after surgical treatment of scaphoid pseudoarthrosis using a cortico-cancellous bone grafting technique. Material and methods. 48 patients who had undergone surgical treatment for scaphoid union failure were examined. The surgical method included the anatomical reconstruction of the scaphoid bone, which resulted in normal ligament tension and carpal stability. The clinical examination included pain evaluation, return to work, range of wrist motion, and grip strength. On comparative x-rays of both wrists we evaluated union, the length and shape of the scaphoid bone, the scapho-lunate angle, the carpal height ratio, and the carpal ulnar shift. Results. Union was obtained in 42 cases. In 26 patients there were no signs of osteoarthritis, while 11 patients had slight degenerative changes in the radio-scaphoid joint. Conclusions. According to our analysis, cortico-cancellous bone grafting is an effective surgical procedure, useful not only in obtaining union, but also in reconstructing the shape and length of the scaphoid and preventing posttraumatic carpal asteoarthritis. PMID:17589397

  11. Three-Dimensional Assessment of Bilateral Symmetry of the Scaphoid: An Anatomic Study

    PubMed Central

    ten Berg, Paul W. L.; Dobbe, Johannes G. G.; Strackee, Simon D.; Streekstra, Geert J.

    2015-01-01

    Preoperative 3D CT imaging techniques provide displacement analysis of the distal scaphoid fragment in 3D space, using the matched opposite scaphoid as reference. Its accuracy depends on the presence of anatomical bilateral symmetry, which has not been investigated yet using similar techniques. Our purpose was to investigate symmetry by comparing the relative positions of distal and proximal poles between sides. We used bilateral CT scans of 19 adult healthy volunteers to obtain 3D scaphoid models. Left proximal and distal poles were matched to corresponding mirrored right sides. The left-to-right positional differences between poles were quantified in terms of three translational and three rotational parameters. The mean (SD) of ulnar, dorsal, and distal translational differences of distal poles relative to proximal poles was 0.1 (0.6); 0.4 (1.2); 0.2 (0.6) mm and that of palmar rotation, ulnar deviation, and pronation differences was −1.1 (4.9); −1.5 (3.3); 1.0 (3.7)°, respectively. These differences did not significantly differ from zero and thus were not biased to left or right side. We proved that, on average, the articular surfaces of scaphoid poles were symmetrically aligned in 3D space. This suggests that the contralateral scaphoid can serve as reference in corrective surgery. No level of evidence is available. PMID:26413532

  12. The Halogen Occultation Experiment

    NASA Technical Reports Server (NTRS)

    Russell, James M., III; Gordley, Larry L.; Park, Jae H.; Drayson, S. R.; Hesketh, W. D.; Cicerone, Ralph J.; Tuck, Adrian F.; Frederick, John E.; Harries, John E.; Crutzen, Paul J.

    1993-01-01

    The Halogen Occultation Experiment (HALOE) uses solar occultation to measure vertical profiles of O3, HCl, HF, CH4, H2O, NO, NO2, aerosol extinction, and temperature versus pressure with an instantaneous vertical field of view of 1.6 km at the earth limb. Latitudinal coverage is from 80 deg S to 80 deg N over the course of 1 year and includes extensive observations of the Antarctic region during spring. The altitude range of the measurements extends from about 15 km to about 60-130 km, depending on channel. Experiment operations have been essentially flawless, and all performance criteria either meet or exceed specifications. Internal data consistency checks, comparisons with correlative measurements, and qualitative comparisons with 1985 atmospheric trace molecule spectroscopy (ATMOS) results are in good agreement. Examples of pressure versus latitude cross sections and a global orthographic projection for the September 21 to October 15, 1992, period show the utility of CH4, HF, and H2O as tracers, the occurrence of dehydration in the Antarctic lower stratosphere, the presence of the water vapor hygropause in the tropics, evidence of Antarctic air in the tropics, the influence of Hadley tropical upwelling, and the first global distribution of HCl, HF, and NO throughout the stratosphere. Nitric oxide measurements extend through the lower thermosphere.

  13. Uranus occults SAO158687. [stellar occultation and planetary parametric observation

    NASA Technical Reports Server (NTRS)

    Elliot, J. L.; Veverka, J.; Millis, R. L.

    1977-01-01

    Experience gained in obtaining atmospheric parameters, oblatenesses, and diameters of Jupiter and Mars from recent stellar occultations by these planets is used to predict what can be learned from the March 1977 occultation of the star SAO158687 by Uranus. The spectra of this star and Uranus are compared to indicate the relative instrument intensities of the two objects, the four passbands where the relative intensities are most nearly equal are listed, and expected photon fluxes from the star are computed on the assumption that it has UBVRI colors appropriate for a K5 main-sequence object. It is shown that low photon noise errors can be achieved by choosing appropriate passbands for observation, and the rms error expected for the Uranus temperature profiles obtained from the occultation light curves is calculated. It is suggested that observers of this occultation should record their data digitally for optimum time resolution.

  14. Reliability of semi-pronated ulnar deviation PA view (billiard view) of the wrist in evaluating the scaphoid.

    PubMed

    Park, Ho Youn; Yoon, Jun O; Kim, Keonghwan; Bae, Kunhyung; Sohn, Dong Wook; Kim, Jin Sam

    2016-07-01

    Various methods assessing the scaphoid have been reported because of its unique position. In our hospital, pre- and postoperative evaluation of the scaphoid alignment has been carried out in the billiard view, a combination of 45° pronated oblique with ulnar deviation posteroanterior (PA) view, in addition to 3DCT scan and PA and lateral view. This study compared the intra- and inter-observer reliabilities of the lateral intrascaphoid angle and scaphoid length (SL) and scaphoid height (SH) on the billiard view. A total of 60 patients who underwent surgery for scaphoid nonunion were identified and the preoperative and the final follow-up postoperative plain radiographs were used for measurement. Three observers assessed each image. Intra- and inter-observer reliability was determined using intra-class correlation (ICC) coefficients. Intra-observer reliability was all excellent ranging between 0.855 and 0.992. Inter-observer reliability ranged between 0.292 and 0.983. SL and SH demonstrated excellent agreement, while ISA demonstrated poor to moderate agreement. The best method for assessing the scaphoid in simple radiograph remains debatable, but our current data suggest that measuring SL and SH on the billiard view is reproducible and can be used for evaluating restoration of scaphoid alignment. PMID:27053512

  15. Pinhole occulter experiment

    NASA Technical Reports Server (NTRS)

    Ring, Jeff; Pflug, John

    1987-01-01

    Viewgraphs and charts from a briefing summarize the accomplishments, results, conclusions, and recommendations of a feasibility study using the Pinhole Occulter Facility (POF). Accomplishments for 1986 include: (1) improved IPS Gimbal Model; (2) improved Crew Motion Disturbance Model; (3) use of existing shuttle on-orbit simulation to study the effects of orbiter attitude deadband size on POF performance; (4) increased understanding of maximum performance expected from current actuator/sensor set; (5) use of TREETOPS nonlinear time domain program to obtain system dynamics describing the complex multibody flexible structures; (6) use of HONEY-X design tool to design and evaluate multivariable compensator for stability, robustness, and performance; (7) application of state-of-the-art compensator design methodology Linear Quadratic Gaussian/Loop Transfer Recovery (LQG/LTR); and (8) examination of tolerance required on knowledge of the POF boom flexible mode frequencies to insure stability, using structure uncertainty analysis.

  16. KPNO LUNAR OCCULTATION SUMMARY. III

    SciTech Connect

    Schmidtke, P. C.; Africano, J. L.

    2011-01-15

    The results for 251 lunar occultation events recorded at Kitt Peak National Observatory are presented, including 20 observations of known or suspected double stars and five measurements of stars with resolved angular diameters.

  17. The Occult: Diabolica to Alchemists

    ERIC Educational Resources Information Center

    Delaney, Oliver J.

    1971-01-01

    The 91 items in this bibliography deal with works of occult science. The material is subdivided into biographies, dictionaries, encyclopedias, handbooks, noteworthy histories, indices, annuals, and a few miscellany works with treatises. (95 references) (Author)

  18. Smoking increases failure rate of operation for established non-union of the scaphoid bone

    PubMed Central

    Vickers, R. H.

    2006-01-01

    The aim of the study was to investigate the effect of smoking on the operative treatment of established non-union of the carpal scaphoid. Case notes and radiographs of patients undergoing bone grafting and screw fixation of scaphoid non-unions were reviewed. There were 34 patients that had undergone 37 operations for established non-union of the carpal scaphoid bone. There were two female patients, and the average age was 26.8 years (range 13.4 years to 52.9 years). The median delay to operation was 11.9 months. The overall success rate of the operation (internal fixation and autologous bone grafting) was 59.5% (22/37), but there was a significant association between non-union and smoking (P=0.02 for Fisher’s exact test). In non-smokers (n=17) the success rate was 82.4%, but this dropped to 40.0% among smokers (P<0.01). We concluded that smoking was significantly associated with failure of operative treatment of established non-union of the scaphoid bone. PMID:16947049

  19. Treatment of scaphoid nonunion with vascularised and nonvascularised dorsal bone grafting from the distal radius

    PubMed Central

    Medina, Carlos Eduardo Gonzalez; Mattar, Rames; Ulson, Heitor Jose Rizzardo; de Resende, Marcelo Rosa; Etchebehere, Mauricio

    2009-01-01

    We conducted a prospective randomised study comparing the clinical, functional and radiographic results of 46 patients treated for scaphoid nonunion using a vascularised bone graft from the dorsal and distal aspect of the radius (group I), relative to 40 patients treated by means of a conventional non-vascularised bone graft from the distal radius (group II). Surgical findings included 30 sclerotic, poorly-vascularised scaphoids in group I versus 20 in group II. Bone fusion was achieved in 89.1% of group I and 72.5% of group II patients (p = 0.024). Functional results were good to excellent in 72.0% of the patients in group I and 57.5% in group II. Considering only patients with sclerotic, poorly-vascularised scaphoids, the mean final outcome scores obtained were 7.5 and 6.0 for groups I and group II, respectively. We conclude that vascularised bone grafting yields superior results and is more efficient when there is a sclerotic, poorly-vascularised proximal pole in patients in scaphoid nonunion. PMID:19730861

  20. Long-term results after Russe bone-grafting: the effect of malunion of the scaphoid.

    PubMed

    Jiranek, W A; Ruby, L K; Millender, L B; Bankoff, M S; Newberg, A H

    1992-09-01

    Twenty-five patients had Russe anterior corticocancellous bone-grafting between 1973 and 1984 for twenty-six symptomatic established non-unions of the scaphoid. The mean duration of follow-up was eleven years (range, seven to eighteen years). Twenty-one (81 per cent) of the twenty-six scaphoid bones united. We developed two rating scales to evaluate the results of the operation. One scale, based on objective findings, included the radiographic appearance of the wrist, the range of motion, and strength; the other scale, based on subjective findings, comprised function, pain, perception of a decrease in performance because of limitation of motion or strength, and satisfaction. These scales were used to compare the objective and subjective results in patients who had a malunion of the scaphoid in which the lateral intrascaphoid angle was more than 45 degrees convex dorsally between the proximal and distal poles (a so-called flexion or humpback deformity, which results in extension of the proximal fragment of the scaphoid at the radiocarpal joint) with the results in patients who had no such deformity. The lateral intrascaphoid angle was more than 45 degrees in thirteen (50 per cent) of the twenty-six wrists. Although the difference in the objective results between the wrists that had a malunion and those that did not have a malunion was highly significant (p = 0.001), there was no significant difference in the subjective results between the two groups, including satisfaction of the patient (p = 0.39). Twenty-three patients (92 per cent) returned to full-time employment and twenty-two (88 per cent), to sports activities. Twenty-three patients (92 per cent) reported that they had pronounced relief of pain and that the procedure had improved their quality of life. The presence of this deformity of the scaphoid after bone-grafting for a symptomatic non-union was not predictive of a poor long-term subjective outcome. PMID:1400550

  1. The IMACS Occultation Survey

    NASA Astrophysics Data System (ADS)

    Payne, Matthew John; Holman, Matthew; Alcock, Charles; Osip, David; Schlichting, Hilke

    2015-11-01

    We report the results of our extended campaign to search for occultations of background stars by small (sub-km) Kuiper belt objects (KBOs) using the IMACS instrument on the Magellan Telescope.We implemented a novel shutterless continuous readout mode on the IMACS instrument, with custom-made aperture masks, permitting simultaneous high-speed (~40 Hz) photometry for numerous stars, while minimizing the effects of stellar crowding and sky background. Observing in the southern hemisphere allows us to target the intersection of the ecliptic and galactic planes, where hundreds of stars can be monitored with a single field of view.We observed for a total of ~28 hours spread over eight nights, obtaining over 10,000 star-hours of light curves with per-point SNR > 10. This represents an order of magnitude increase in star hours compared to the previous best ground-based survey by Bianco et al. (2009). Our results allow us to place strong constraints on the surface density of sub-km objects in the Kuiper-Belt, as well as to complement the HST FGS results of Schlichting et al. (2009, 2012).

  2. Home Use Tests: Fecal Occult Blood

    MedlinePlus

    ... Procedures In Vitro Diagnostics Home Use Tests Fecal Occult Blood Share Tweet Linkedin Pin it More sharing ... test kit to measure the presence of hidden (occult) blood in your stool (feces). What is fecal ...

  3. Manned Mars mission sunlight and communication occultations

    NASA Technical Reports Server (NTRS)

    Mulqueen, Jack

    1986-01-01

    Calculations are presented for the 1999 opposition class mission and a procedure for obtaining singlar occultation data for any other given Mars mission is given. Occultation data for a Mars orbiter in a 24.5 hour parking orbit and a Mars base were calculated for: sunlight occultation - the time in darkness; and radio communication occultation - the communication losses between the lander and the orbiter, the lander and Earth, and orbiter and Earth.

  4. Testing for Occult Heartworm Infection

    PubMed Central

    Stogdale, L.

    1984-01-01

    Heartworm infection in dogs is endemic in southern Ontario but occurs only sporadically throughout the remainder of Canada. The disease may either be associated with microfilariae in the patient's blood, a patent infection, or it may be occult. This paper describes a case of occult dirofilariasis in a dog, with emphasis on the diagnosis. A patent infection could be missed if the clinician tests an insufficient amount of blood. He should perform multiple concentration tests using either the modified Knott's technique or a filtration method. Occult infections occur in prepatent or unisexual infections, when the worms become sterile following therapy, or when the host produces antibodies that result in the destruction of the microfilariae. The recent release of a kit which detects the presence of antibodies to the adult heartworms now enables veterinarians to make an accurate diagnosis in the vast majority of dogs. PMID:17422386

  5. Occult Participation: Its Impact on Adolescent Development.

    ERIC Educational Resources Information Center

    Tennant-Clark, Cynthia M.; And Others

    1989-01-01

    Investigated relationship between occult participation, substance abuse, and level of self-esteem among 25 clinical (alcohol or drug treatment) and 25 nonclinical adolescents. Results indicated that adolescent substance abuse and occult participation were significantly related. Found significant differences between high versus low occult groups…

  6. Predicted occultations by Uranus - 1981-1984

    NASA Technical Reports Server (NTRS)

    Klemola, A. R.; Mink, D. J.; Elliot, J. L.

    1981-01-01

    Predictions are presented for 11 occultations by and appulses to Uranus and its ring system for ten stars from 1981 through 1984. The brightest stars are occulted on April 26, 1981 (BD - 19 deg 4222) and on April 22, 1982 (Hyd - 20 deg 51699). The ring system occults the same star twice during March 1983 (Hyd - 21 deg 64352).

  7. Solar Occultation Retrieval Algorithm Development

    NASA Technical Reports Server (NTRS)

    Lumpe, Jerry D.

    2004-01-01

    This effort addresses the comparison and validation of currently operational solar occultation retrieval algorithms, and the development of generalized algorithms for future application to multiple platforms. initial development of generalized forward model algorithms capable of simulating transmission data from of the POAM II/III and SAGE II/III instruments. Work in the 2" quarter will focus on: completion of forward model algorithms, including accurate spectral characteristics for all instruments, and comparison of simulated transmission data with actual level 1 instrument data for specific occultation events.

  8. New Occultation Systems and the 2005 July 11 Charon Occultation

    NASA Astrophysics Data System (ADS)

    Young, L. A.; French, R. G.; Gregory, B.; Olkin, C. B.; Ruhland, C.; Shoemaker, K.; Young, E. F.

    2005-08-01

    Charon's density is an important input to models of its formation and internal structure. Estimates range from 1.59 to 1.83 g/cm3 (Olkin et al. 2003. Icarus 164, 254), with Charon's radius as the main source of uncertainty. Reported values of Charon's radius from mutual events range from 593±13 (Buie et al. 1992, Icarus 97, 211) to 621±21 km (Young & Binzel 1994, Icarus 108), while an occultation observed from a single site gives a lower limit on the radius of 601.5 km (Walker 1980 MNRAS 192, 47; Elliot & Young 1991, Icarus 89, 244). On 2005 July 11 UT (following this abstract submission date), Charon is predicted to occult the star C313.2. If successful, this event will be the first Charon occultation observed since 1980, and the first giving multiple chords across Charon's disk. This event is expected to measure Charon's radius to 1 km. Our team is observing from three telescopes in Chile, the 4.0-m Blanco and the 0.9-m telescopes at Cerro Tololo and the 4.2-m SOAR telescope at Cerro Pachon. At SOAR, we will be using the camera from our new PHOT systems (Portable High-speed Occultation Telescopes). The PHOT camera is a Princeton Instrument MicroMAX:512BFT from Roper Scientific, a 512×512 frame-transfer CCD with a readnoise of only 3 electrons at the 100 kHz digitization rate. The camera's exposures are triggered by a custom built, compact, stand-alone GPS-based pulse-train generator. A PHOT camera and pulse-train generator were used to observe the occultation of 2MASS 1275723153 by Pluto on 2005 June 15 UT from Sommers-Bausch Observatory in Boulder Colorado; preliminary analysis shows this was at best a grazing occultation from this site and a successful engineering run for the July 11 Charon occultation. The work was supported, in part, by NSF AST-0321338 (EFY) and NASA NNG-05GF05G (LAY).

  9. TREATMENT OF SCAPHOID NONUNION WITH OLECRANON BONE GRAFT AND COMPRESSION SCREW

    PubMed Central

    NEDER, ANTONIO TUFI; FRANCESCHINI, EDUARDO TRALDI; PARDINI, ARLINDO GOMES; RIBERTO, MARCELO; MAZZER, NILTON

    2016-01-01

    ABSTRACT Objective: To evaluate the outcome of olecranon bone graft and compression screw for the treatment of nonunion of the Lichtman type I scaphoid. Method: We evaluated 15 patients of 32 who underwent surgical treatment for nonunion of the Lichtman type I scaphoid with olecranon bone graft and screw compression. Results: We obtained 100% consolidation in our sample. The mean flexion of the wrist on the affected side was 68° and 75° on the non-affected side. The average extension was 63° and 72°, respectively. The average grip strength was 35 kgf. This corresponds to 98% of the handgrip strength of the non-affected side, which was 37 kgf. The DASH score averaged 5 points. Conclusion: We believe that the use of bone graft obtained from the olecranon and secured with cannulated screw is a resolute technique for cases of linear nonunion of the Lichtmann type I scaphoid. It has the advantages of a new anesthesia for removal of the graft and the access is easy, providing a good exposure for removal and good aesthetic results. Level of evidence IV. Case series. PMID:27217819

  10. Treatment of Scaphoid Nonunions with Closed-Wedge Osteotomy of the Distal Radius: Report of Six Cases

    PubMed Central

    2007-01-01

    Background The ideal treatment of nonunion of the scaphoid remains unresolved and controversial. It was hypothesized that scaphoid nonunion could be treated successfully using a closed-wedge osteotomy of the distal radius which reduces the inclination of the joint surface and decreases the pressure between the radial and scaphoid surfaces with a reduction of the force applied by the styloid process. We present a preliminary report in six patients with nonunion of the carpal scaphoid using this procedure. The main objective of the osteotomy is to achieve fusion, alleviate pain, and improve function. Materials and Methods Six closed-wedge osteotomies to reduce the inclination of the distal radial surface were performed in patients with scaphoid waist nonunion and a viable proximal pole, without posttrauma osteoarthritis or with moderate posttraumatic osteoarthritis confined to the radio-scaphoid joint. The present series of six patients (all men) were followed for at least 8 months (mean follow-up 14.2 months, range 8–21 months). Results Solid union was achieved in five patients. Postoperatively, three patients were pain-free, two presented mild pain for heavy work, and one had moderate pain. This type of osteotomy reduced the inclination of the joint surface (radial angulation) 6.2° on average. There was an improvement in joint flexion from a preoperative mean of 40° to 52.5° at last follow-up, in extension from 40.8° to 66.7°, in radial deviation from 15° to 22.5°, and in ulnar deviation from 30.8° to 41.7°. Conclusions This preliminary study suggests that a closed-wedge osteotomy of the distal radius could be an alternative approach for patients with scaphoid waist nonunion and a viable proximal pole, without posttrauma osteoarthritis or with moderate posttraumatic osteoarthritis confined to the radio-scaphoid joint. The number of cases was small; however, further studies with a much larger series are needed before routine use of wedge osteotomy in

  11. Occultation studies of the Solar System

    NASA Technical Reports Server (NTRS)

    Millis, Robert L.

    1987-01-01

    The planetary occultation program began at Lowell Observatory in 1973 with a worldwide campaign to observe mutual occultations and eclipses of the Galilean Satellites. Then the temperature profile of the Martian atmosphere was measured from data taken during the occultation of epsilon Geminorum, the Rings of Uranus were discovered as they occulted SAO 158687, and the dimensions of Pallas were measured when that minor planet occulted SAO 85009. In 1979 the present grant was initiated, providing funds for portable photometric instrumentation used to observe occultations by asteroids as well as by Uranus and Neptune. Software for predicting occultations of catalog stars by asteroids, planets, and comets was written in 1983. Lowell currently provides most of the available predictions for asteroid occultations. Realizing in 1983 that the lack of a high-quality astrometric telescope dedicated to occultation work was limiting progress, an 18-inch, F/8 lens was acquired and adapted to an existing mounting at Lowell. Although acquisition of the lens and implementation of the new telescope has been accomplished primarily with non-grant funds, the instrument makes a major contribution to occultation research.

  12. Screening for occult lung cancer.

    PubMed Central

    Barclay, T. H.; MacIntosh, J. H.

    1983-01-01

    A pilot screening program for the early detection of lung cancer was carried out in Saskatchewan in 1968 using chest roentgenography and cytologic examination of sputum samples. The yield from 23 000 men aged 40 years and over was only 10 cases. Nine of the men had advanced disease. One had occult lung cancer. A period of 31 months elapsed between the discovery of malignant cells in this patient's sputum and roentgenographic localization of the tumour. Following pneumonectomy he has survived with no discernible residual or metastatic tumour for 12 years. The morphologic changes in the resected lung provided a basis for discussing the preclinical phase of squamous cancer of the lung, the treatment of occult cancer and multicentric primary pulmonary tumours. The survey would have been more successful with a narrower target group and more frequent examination. Images FIG. 1 FIG. 2 FIG. 3 PMID:6299495

  13. Triton stellar occultation candidates - 1992-1994

    NASA Technical Reports Server (NTRS)

    Mcdonald, S. W.; Elliot, J. T.

    1992-01-01

    A search for Triton stellar occultation candidates for the period 1992-1994 has been completed with CCD strip-scanning observations. The search reached an R magnitude of about 17.4 and found 129 candidates within 1.5 arcsec of Triton's ephemeris during this period. Of these events, around 30 occultations are expected to be visible from the earth, indicating that a number of Triton occultation events should be visible from major observatories. Even the faintest of the present candidate events could produce useful occultation data if observed with a large enough telescope. The present astrometric accuracy is inadequate to identify which of these appulse events will produce occultations on the earth; further astrometry is needed to refine the predictions for positive occultation identification. To aid in selecting candidates for additional astrometric and photometric studies, finder charts and earth-based visibility charts for each event are included.

  14. Revisiting the 1988 Pluto Occultation

    NASA Astrophysics Data System (ADS)

    Bosh, Amanda S.; Dunham, Edward W.; Young, Leslie A.; Slivan, Steve; Barba née Cordella, Linda L.; Millis, Robert L.; Wasserman, Lawrence H.; Nye, Ralph

    2015-11-01

    In 1988, Pluto's atmosphere was surmised to exist because of the surface ices that had been detected through spectroscopy, but it had not yet been directly detected in a definitive manner. The key to making such a detection was the stellar occultation method, used so successfully for the discovery of the Uranian rings in 1977 (Elliot et al. 1989; Millis et al. 1993) and before that for studies of the atmospheres of other planets.On 9 June 1988, Pluto occulted a star, with its shadow falling over the South Pacific Ocean region. One team of observers recorded this event from the Kuiper Airborne Observatory, while other teams captured the event from various locations in Australia and New Zealand. Preceding this event, extensive astrometric observations of Pluto and the star were collected in order to refine the prediction.We will recount the investigations that led up to this important Pluto occultation, discuss the unexpected atmospheric results, and compare the 1988 event to the recent 2015 event whose shadow followed a similar track through New Zealand and Australia.

  15. Scaling Relation for Occulter Manufacturing Errors

    NASA Technical Reports Server (NTRS)

    Sirbu, Dan; Shaklan, Stuart B.; Kasdin, N. Jeremy; Vanderbei, Robert J.

    2015-01-01

    An external occulter is a spacecraft own along the line-of-sight of a space telescope to suppress starlight and enable high-contrast direct imaging of exoplanets. The shape of an external occulter must be specially designed to optimally suppress starlight and deviations from the ideal shape due to manufacturing errors can result loss of suppression in the shadow. Due to the long separation distances and large dimensions involved for a space occulter, laboratory testing is conducted with scaled versions of occulters etched on silicon wafers. Using numerical simulations for a flight Fresnel occulter design, we show how the suppression performance of an occulter mask scales with the available propagation distance for expected random manufacturing defects along the edge of the occulter petal. We derive an analytical model for predicting performance due to such manufacturing defects across the petal edges of an occulter mask and compare this with the numerical simulations. We discuss the scaling of an extended occulter test-bed.

  16. Exploring the Solar System with Stellar Occultations

    NASA Technical Reports Server (NTRS)

    Elliot, J. L.; Dunham, E. W.

    1984-01-01

    By recording the light intensity as a function of time when a planet occults a relatively bright star, the thermal structure of the upper atmosphere of the planet can be probed. The main feature of stellar occultation observations is their high spatial resolution, typically several thousand times better than the resolution achievable with ground-based imaging. Five stellar occultations have been observed. The main results of these observations are summarized. Stellar occultations have been observed on Uranus, Mars, Pallas, Neptune and the Jovian Ring.

  17. Nose fracture

    MedlinePlus

    Fracture of the nose; Broken nose; Nasal fracture; Nasal bone fracture; Nasal septal fracture ... A fractured nose is the most common fracture of the face. It ... with other fractures of the face. Sometimes a blunt injury can ...

  18. Asteroid Occultations V14.0

    NASA Astrophysics Data System (ADS)

    Dunham, D. W.; Herald, D.; Frappa, E.; Hayamizu, T.; Talbot, J.; Timerson, B.

    2016-06-01

    This data set is intended to include all reported timings of observed asteroid, planet, and planetary satellite occultation events as well as occultation axes derived from those timings by David W. Dunham and David Herald. This version is complete through the end of 2015.

  19. Occult hemorrhage in children with severe ITP.

    PubMed

    Flores, Adolfo; Buchanan, George R

    2016-03-01

    Little is known about the frequency and significance of clinically unapparent or occult hemorrhage in ITP. Therefore, we prospectively explored the sites and frequency of occult bleeding in children with severe ITP at diagnosis or upon symptomatic relapse in a prospective, single-institution cohort study of patients ≤ 18 years of age and a platelet count ≤ 10,000/mm(3) . Data collected included bleeding severity assessment, urinalysis, fecal occult blood testing, and non-contrast brain MRI. Stool and urine samples were tested within 7 days of diagnosis or symptomatic relapse. Three months after diagnosis or relapse a noncontrast brain MRI evaluated hemosiderin deposits resulting from prior localized hemorrhage. Fifty-two ITP patients were enrolled with a mean platelet count of 4,000/mm(3) . A significant occurrence of occult hemorrhage was identified in the urine (27%) compared with clinically overt hematuria (0.91%, P < 0.0005). CNS microbleeding in the superficial cortex of the left frontal lobe was identified in one child with occult bleeding in the urinary tract. There was no relationship between occult hemorrhage and bleeding manifestations on physical examination. Occult hemorrhage was not a harbinger of subsequent bleeding. Our findings suggest that occult hemorrhage occurs with greater frequency than overt bleeding in children with severe ITP. CNS microbleeding is a potential risk in this patient population. Assessment of brain microbleeds and microscopic hematuria in this patient population require additional study. PMID:26661930

  20. Seeing effects on occultation curves.

    NASA Technical Reports Server (NTRS)

    Young, A. T.

    1971-01-01

    Evaluation of seeing effects on the light curve of a stellar occultation by the moon. Some theoretical studies of Fried (1966) and Hulett (1967) on the linear size of the downward-looking seeing disk are cited, showing that the seeing blur amounts to a few centimeters for a star in the zenith and that the linear blur must grow approximately as (sec z) to the 3/2 power. For most observations the seeing blur will not exceed 8 to 10 cm. The limitation on angular resolution imposed by this seeing effect is calculated.

  1. Occult cocaine exposure in children.

    PubMed

    Rosenberg, N M; Meert, K L; Knazik, S R; Yee, H; Kauffman, R E

    1991-12-01

    We determined the prevalence of cocaine and cannabinoid exposure among young children presenting to an urban pediatric emergency department without signs or symptoms suggestive of the exposure. The study included 460 children between 1 and 60 months of age in whom urinalysis was required for investigation of routine pediatric complaints. Anonymously and without informed consent, an aliquot of urine was screened for cocaine metabolite (benzoylecgonine) and 11- or delta-9-tetrahydrocannabinol-9 carboxylic acid with the enzyme multiplied immunoassay technique. Positive specimens were rescreened with a radioimmunoassay and confirmed with gas chromatography/mass spectrometry, if a sufficient quantity of urine was available. Benzoylecgonine was identified in 25 patients (5.4%) by both screening techniques. Enough urine was available for confirmatory testing in eight patients, and all eight urine specimens contained benzoylecgonine. Neither 11- nor delta-9-tetrahydrocannabinol-9 carboxylic acid was detected in any patient. We documented the magnitude of the problem of occult passive cocaine exposure in young children living in an urban environment. Such exposure has serious implications for the assessment of outcomes in postnatal follow-up studies of prenatally exposed children as well as potential risks to children living in household environments where occult cocaine exposure occurs. PMID:1669673

  2. Quantification of contralateral differences of the scaphoid: a comparison of bone geometry in three dimensions.

    PubMed

    Letta, Claudio; Schweizer, Andreas; Fürnstahl, Philipp

    2014-01-01

    The purpose of this study was to accurately quantify contralateral differences of the scaphoid in three-dimensional space to evaluate the feasibility of using the healthy contralateral bone as a reconstruction template in the preoperative planning of complex mal- or nonunions. Three-dimensional surface models of the left and right scaphoids were reconstructed from computed tomography images and compared in 26 individuals. Left-right differences were quantified with respect to volume, surface area, length, and surface-to-surface deviation. The average left-right differences in volume, surface area, and length were 95.4 mm(3) (SD 66.2 mm(3)), 32.7 mm(2) (SD 22.9 mm(32)), and 0.28 mm (SD 0.4 mm), respectively. The average surface-to-surface deviation between the sides was 0.26 mm (SD 0.2 mm). High statistical correlation (Pearson) between the left and the right side was found in all evaluated measures. PMID:24715983

  3. Early detection of occult atrial fibrillation and stroke prevention.

    PubMed

    Keach, Joseph Walker; Bradley, Steven M; Turakhia, Mintu P; Maddox, Thomas M

    2015-07-01

    Atrial fibrillation (AF) is a very common arrhythmia and significantly increases stroke risk. This risk can be mitigated with oral anticoagulation, but AF is often asymptomatic, or occult, preventing timely detection and treatment. Accordingly, occult AF may cause stroke before it is clinically diagnosed. Currently, guidelines for the early detection and treatment of occult AF are limited. This review addresses recent advancements in occult AF detection methods, identification of populations at high risk for occult AF, the treatment of occult AF with oral anticoagulation, as well as ongoing trials that may answer critically important questions regarding occult AF screening. PMID:25935765

  4. Nose fracture

    MedlinePlus

    Fracture of the nose; Broken nose; Nasal fracture; Nasal bone fracture; Nasal septal fracture ... A fractured nose is the most common fracture of the face. It usually occurs after an injury and often occurs with ...

  5. Pediatric stress fractures: a pictorial essay

    PubMed Central

    Shelat, Nirav H.; El-Khoury, Georges Y.

    2016-01-01

    More children are participating in organized and recreational athletics at a younger age. It has been well documented that increased athletic specialization and year-round activities have resulted in higher incidences of overuse injuries, including stress fractures and stress reactions. Initially, stress fractures can be radiographically occult. Continued stress on the injured bone or cartilage can lead to progressive radiographic changes. Because of the prevalence of these injuries, both orthopedic surgeons and radiologists should be aware of the radiographic and magnetic resonance imaging (MRI) features of common stress fractures in children. This article reviews frequently encountered stress fractures involving various bones in the pediatric population. PMID:27528851

  6. The Lunar Occultation Observer (LOCO) mission concept

    NASA Astrophysics Data System (ADS)

    Miller, Richard S.

    2007-09-01

    The hard X-ray sky has tremendous potential for future discoveries and is one of the last electromagnetic regimes without a sensitive all-sky survey. A new approach to such a survey is to utilize the Moon as an occulting disk. The Lunar Occultation Observer (LOCO) mission concept, based on this Lunar Occultation Technique (LOT) and incorporating advanced inorganic scintillators as a detection medium, represents a sensitive and cost effective option for NASA's Beyond Einstein Black Hole Finder Probe or a future Explorer-class mission. We present the motivating factors for the LOT, outline developmental details and simulation results, as well as give preliminary estimates for source detection sensitivity.

  7. Stellar Occultation Studies of the Solar System

    NASA Technical Reports Server (NTRS)

    Elliot, James L.

    1998-01-01

    Earth-based observations of stellar occultations provide extremely high spatial resolution for bodies in the outer solar system, about 10,000 times better than that of traditional imaging observations. Stellar occultation data can be used to establish the structure of atmospheres and rings of solar system bodies at high spatial resolution. Airborne occultation observations are particularly effective, since the controlled mobility of the observing platform allows the observer to fly within the optimum part of the occultation shadow for most events that are visible from Earth. Airborne observations are carried out above any clouds and are nearly free of scintillation noise from the Earth's atmosphere. KAO occultation observations resulted in the first detection of gravity waves in the Martian atmosphere, discovery of the Uranian rings, the first detection of Pluto's atmosphere, the first Earth-based investigations of Triton's atmosphere, and the discovery of narrow jets from Chiron's nucleus. The first SOFIA occultation opportunity will be an investigation of Pluto's atmospheric structure in November, 2002, and will resolve a problem that has lingered since the KAO discovery observation fourteen years earlier. We plan to continue our successful airborne occultation program with the greatly enhanced capability provided by SOFIA. We propose here to replace our KAO occultation photometer with one having twice the throughput, half the noise, a somewhat wider wavelength range, four times the field of view, and ten times the frame rate to optimize its performance and to capitalize on the larger collecting area offered by SOFIA. It will also allow for simultaneous visible and IR occultation observations, greatly enriching the results that we can obtain from occultations. We call this new imaging occultation photometer HOPI (High-speed Occultation Photometer and Imager). HOPI will provide a signal-to-noise ratio two to four times that of our present photometer for a given

  8. The Approach to Occult Gastrointestinal Bleed.

    PubMed

    Naut, Edgar R

    2016-09-01

    Occult gastrointestinal bleeding is not visible and may present with a positive fecal occult blood test or iron deficiency anemia. Obscure bleeding can be overt or occult, with no source identified despite an appropriate diagnostic workup. A stepwise approach to this evaluation after negative upper and lower endoscopy has been shown to be cost effective. This includes repeat endoscopies if warranted, followed by video capsule endoscopy (VCE) if no obstruction is present. If the VCE is positive then specific endoscopic intervention may be possible. If negative, patients may undergo either repeat testing or watchful waiting with iron supplements. PMID:27542424

  9. Skull fracture

    MedlinePlus

    Basilar skull fracture; Depressed skull fracture; Linear skull fracture ... Skull fractures may occur with head injuries . The skull provides good protection for the brain. However, a severe impact ...

  10. Reflective Occultation Mask for Evaluation of Occulter Designs for Planet Finding

    NASA Technical Reports Server (NTRS)

    Hagopian, John; Lyon, Richard; Shiri, Shahram; Roman, Patrick

    2011-01-01

    Advanced formation flying occulter designs utilize a large occulter mask flying in formation with an imaging telescope to block and null starlight to allow imaging of faint planets in exosolar systems. A paper describes the utilization of subscale reflective occultation masks to evaluate formation flying occulter designs. The use of a reflective mask allows mounting of the occulter by conventional means and simplifies the test configuration. The innovation alters the test set-up to allow mounting of the mask using standard techniques to eliminate the problems associated with a standard configuration. The modified configuration uses a reflective set-up whereby the star simulator reflects off of a reflective occulting mask and into an evaluation telescope. Since the mask is sized to capture all rays required for the imaging test, it can be mounted directly to a supporting fixture without interfering with the beam. Functionally, the reflective occultation mask reflects light from the star simulator instead of transmitting it, with a highly absorptive carbon nanotube layer simulating the occulter blocking mask. A subscale telescope images the star source and companion dim source that represents a planet. The primary advantage of this is that the occulter can be mounted conventionally instead of using diffractive wires or magnetic levitation.

  11. PICO: Portable Instrument for Capturing Occultations

    NASA Astrophysics Data System (ADS)

    Lockhart, Matthew; Person, Michael J.; Elliot, J. L.; Souza, Steven P.

    2010-10-01

    We describe a portable imaging photometer for the observation of stellar occultation events by Kuiper Belt objects (KBOs) and other small bodies. The system is referred to as the Portable Instrument for Capturing Occultations (PICO). It is designed to be transportable to remote observing sites by a single observer. A GPS timing system is used to trigger exposures of a Finger Lakes Instrumentation ML261E-25 camera to facilitate the combination of observational results from multiple sites. The system weighs a total of 11 kg when packed into its single rigid 55.1 × 35.8 × 22.6 cm container, meeting current airline size and weight limits for carry-on baggage. Twelve such systems have been constructed. Nine systems were deployed for observation of a stellar occultation by Kuiper Belt object 55636 in 2009 October. During the same month, one system was used to record a stellar occultation by minor planet 762 Pulcova.

  12. Study of the technique of stellar occultation

    NASA Technical Reports Server (NTRS)

    Hays, P. B.; Graves, M. E.; Roble, R. G.; Shah, A. N.

    1973-01-01

    The results are reported of a study of the stellar occultation technique for measuring the composition of the atmosphere. The intensity of starlight was monitored during the occultation using the Wisconsin stellar ultraviolet photometers aboard the Orbiting Astronomical Observatory (OAO-A2). A schematic diagram of an occultation is shown where the change in intensity at a given wavelength is illustrated. The vertical projection of the attenuation region is typically 60 km deep for molecular oxygen and 30 km deep for ozone. Intensity profiles obtained during various occultations were analyzed by first determining the tangential columm density of the absorbing gases, and then Abel inverting the column densities to obtain the number density profile. Errors are associated with each step in the inversion scheme and have been considered as an integral part of this study.

  13. Scaling Relation for Occulter Manufacturing Errors

    NASA Technical Reports Server (NTRS)

    Sirbu, Dan; Shaklan, Stuart B.; Kasdin, N. Jeremy; Vanderbei, Robert J.

    2015-01-01

    For directly imaging exoplanets, NASA is considering space mission designs that use an external occulter as the principal starlight suppression system. These occulter designs range in diameter from 16 to 40 meters and separation distance from 8,000 to 60,000 kilometers for telescopes with primary diameters of 0.5 to 4 meters. Occulter shapes are solutions to an optimization problem which seeks to maximize suppression in the shadow subject to constraints such as size, separation, and wavelengths. These designs are based on scalar diffraction theory and must be verified experimentally to demonstrate predicted on-orbit performance. Due to the large sizes and separations involved the experiment must be scaled to lab size. We are currently expanding the existing experimental test-bed at Princeton to enable scaling of occulters operating at flight Fresnel sizes. Here we examine the effect on suppression performance of edge defects and their scaling to test-bed size.

  14. McDonald's and the Occult.

    ERIC Educational Resources Information Center

    Singer, Barry

    1979-01-01

    Discusses "occult" and "paranormal" literature which is often mistaken for nonfiction. Suggests that most publishers are unwilling to publish scientific perspectives on the paranormal because such writings would be unmarketable. Journal availability: see SO 507 190. (KC)

  15. Triton stellar occultation candidates: 1995-1999

    NASA Technical Reports Server (NTRS)

    Mcdonald, S. W.; Elliot, J. L.

    1995-01-01

    We have completed a search for candidates for stellar occultations by Triton over the years 1995-1999. CCd strip scan images provided star positions in the relevant sky area to a depth of about 17.5 R magnitude. Over this time period, we find that Triton passes within 1.0 arcsec of 75 stars. Appulses with geocentric minimum separations of less than 0.35 arcsec will result in stellar occultations, but further astrometry and photometry is necessary to refine individual predictions for identification of actual occultations. Finder charts are included to aid in further studies and prediction refinement. The two most promising potential occultations, Tr176 and Tr180, occur in 1997.

  16. Cassini SOI Radio Occultation of Saturn's Rings

    NASA Astrophysics Data System (ADS)

    Marouf, E.; French, R.; Rappaport, N.; Thomson, F.; McGhee, C.; Asmar, S.; Johnston, D.

    2004-11-01

    On July 1, 2005 at 01:12 SCET-UTC, Cassini started the engine burn required to insert the spacecraft into orbit around Saturn (SOI). Almost 30 minutes later, Cassini was occulted by Saturn's rings as seen from the Earth. The geometric ring occultation covered all main ring features, starting at the outer edge of Ring A at 01:42 and ending at the inner edge of Ring C at 02:40. From 01:12 to 03:07, Cassini X-band radio signal (3.6 cm-wavelength) was turned on, primarily to monitor the burn. The sinusoidal transmitted signal was referenced to the on board ultrastable oscillator, allowing measurement of the signal amplitude and phase at the 70-m ground receiving station of the Deep Space Network at Canberra, Australia. As a useful by-product, a complete ring occultation observation, including free-space baseline, was achieved. Because of the special orientation of the spacecraft during the burn, the Cassini low-gain antenna was used to transmit the signal. Nominal radio occultations are conducted using the high-gain antenna, hence have intrinsic free-space signal-to-noise ratio (SNR) higher by a factor of 10,000 than the SOI occultation. Nonetheless, clearly detectable signal was observed during occultation by features in Rings A, Cassini Division, and Ring C, but not Ring B. The measurements, after reconstruction to remove diffraction effects, may be used to obtain an optical-depth and phase-shift profiles of resolved ring features. Achievable radial resolution primarily depends on the ring-opening-angle B, available free-space SNR, and occultation geometry. We compare radial resolution achievable for the Cassini SOI occultation (B = 24.7 deg, SNR = 10 dB-Hz) with those of the Voyager ring occultation (B = 5.9 deg, SNR = 50 dB-Hz), and contrast the results with those expected from nominal radio occultations during the Cassini tour. Example optical depth profiles from the Cassini SOI occultation are presented.

  17. Radio occultation measurements of the lunar ionosphere.

    NASA Astrophysics Data System (ADS)

    Pluchino, S.; Schillirò, F.; Salerno, E.; Pupillo, G.; Maccaferri, G.; Cassaro, P.

    Radio occultation measurements by using interplanetary probes is a well known technique to obtain information on planetary atmospheres. To further understand the morphology of the lunar ionosphere we performed radio occultation experiments by using the radio sounding technique. This method mainly consists in the analisys of the effects produced on the radio wave transmitted from the spacecraft to the Earth when it crosses the atmosphere. The wave amplitude and phase undergo modifications that are correlated to the physical parameters - i.e. electron density - of the crossed medium. The first data set was obtained during the lunar occultations of the European probe SMART-1 shortly before impacting the lunar soil on September 3rd, 2006. During this experiment several radio occultation measurements of the signal transmitted by the spacecraft were performed in S and X band by using the 32 meters radiotelescopes (at Medicina and Noto) of the Istituto di Radioastronomia - Istituto Nazionale di Astrofisica. Further experiments were performed during lunar occultations of Saturn and Venus. On May 22nd and June 18th 2007 the Cassini spacecraft, orbiting Saturn, and the Venus Express spacecraft, orbiting Venus, respectively were occulted by the Moon. The variation of the Total Electron Content (TEC) measured by our instruments (˜ 1013 el/m2) on this occasion is in agreement with values of the electron number density acquired by in situ measuments of the US Apollo missions and the USSR Luna 19 and 22 probes.

  18. Method of Modeling and Simulation of Shaped External Occulters

    NASA Technical Reports Server (NTRS)

    Lyon, Richard G. (Inventor); Clampin, Mark (Inventor); Petrone, Peter, III (Inventor)

    2016-01-01

    The present invention relates to modeling an external occulter including: providing at least one processor executing program code to implement a simulation system, the program code including: providing an external occulter having a plurality of petals, the occulter being coupled to a telescope; and propagating light from the occulter to a telescope aperture of the telescope by scalar Fresnel propagation, by: obtaining an incident field strength at a predetermined wavelength at an occulter surface; obtaining a field propagation from the occulter to the telescope aperture using a Fresnel integral; modeling a celestial object at differing field angles by shifting a location of a shadow cast by the occulter on the telescope aperture; calculating an intensity of the occulter shadow on the telescope aperture; and applying a telescope aperture mask to a field of the occulter shadow, and propagating the light to a focal plane of the telescope via FFT techniques.

  19. Progress on an external occulter testbed at flight Fresnel numbers

    NASA Astrophysics Data System (ADS)

    Kim, Yunjong; Sirbu, Dan; Galvin, Michael; Kasdin, N. Jeremy; Vanderbei, Robert J.

    2016-01-01

    An external occulter is a spacecraft flown along the line-of-sight of a space telescope to suppress starlight and enable high-contrast direct imaging of exoplanets. Laboratory verification of occulter designs is necessary to validate the optical models used to design and predict occulter performance. At Princeton, we have designed and built a testbed that allows verification of scaled occulter designs whose suppressed shadow is mathematically identical to that of space occulters. The occulter testbed uses 78 m optical propagation distance to realize the flight Fresnel numbers. We will use an etched silicon mask as the occulter. The occulter is illuminated by a diverging laser beam to reduce the aberrations from the optics before the occulter. Here, we present first light result of a sample design operating at a flight Fresnel number and the mechanical design of the testbed. We compare the experimental results with simulations that predict the ultimate contrast performance.

  20. Intraosseous Ganglion Cyst of Scaphoid treated by Curettage and Bone Grafting: Case report and Review

    PubMed Central

    Jain, Saurabh; Jain, Anil Kumar; Dhammi, Ish Kumar; Mishra, Puneet; Modi, Prasant

    2011-01-01

    Introduction: Intraosseous ganglions, although share same pathology as the soft tissue ganglions are rare entities, further rare in carpals. Cases of intraosseous ganglions are reported in literature mostly in lower limbs and lunate among carpals, with treatment options ranging from curettage and grafting to calcium phosphate cement injection and finally to arthroscopic treatment. Case report: Here, we present a case of 2 years follow up of 40 years old female with nonspecific clinical finding of wrist and slight limitation of restriction of motion, diagnosed as intraosseous ganglion cyst of scaphoid. This case was treated with curettage and bone grafting having excellent results with visual and analog pain scores reduced from 68 to 11 and range of motion was 90° extension to 80° flexion and full grip strength. Conclusion: Intraosseous ganglion cyst should be considered in differential diagnosis of chronic dull wrist pain because they produce disabling symptoms which ceases once adequately treated by curettage and bone grafting.

  1. Ring Orbits from Multiple Occultation Observations

    NASA Astrophysics Data System (ADS)

    French, Richard G.; McGhee, C. A.; Marouf, E. A.; Rappaport, N.

    2006-09-01

    Planetary rings provide a remarkable laboratory for the investigation of a wide range of dynamical effects, including resonance-driven density and bending waves, satellite wakes, shepherding of narrow ringlets, and non-circular edges of gaps. Careful quantitative examination of these features requires a very accurate absolute radius scale and planetary pole direction, achievable by combining multiple stellar and radio occultation observations. Uncertainty in the location of the spacecraft (at the km level) introduces a fundamental uncertainty into the geometric solution for the ring radius scale, and in the end one must solve for corrections to the spacecraft trajectory as part of the overall determination of the ring orbital model. Using JPL's NAIF toolkit, we have developed accurate algorithms for computing the event time of a ring occultation during an Earth-based or spacecraft occultation, including the effects of spacecraft trajectory errors mapped in two orthogonal directions transverse to the line of sight, based on osculating orbital elements for the instantaneous spacecraft path. These are the fundamental building blocks for a global solution for the pole direction and orbits of the rings of Saturn and Uranus. For Uranus, our new orbit solution includes the full set of digitally recorded occultation data from 1977-2002, yielding a radius scale accurate at the 100 meter level. For Saturn, we explore the potential for highly accurate ring orbit determination as occultation observations from dozens of stellar and radio occultations become publicly available over the course of the ongoing Cassini orbital tour. Saturn's pole precession is also detectable from ring occultation data, and we set limits on the accuracy of the precession rate determination and the implications for our understanding of the mass distribution in Saturn's interior. This work was supported in part by the NASA PGG program.

  2. Experiment D005: Star occultation navigation

    NASA Technical Reports Server (NTRS)

    Silva, R. M.; Jorris, T. R.; Vallerie, E. M., III

    1971-01-01

    The usefulness of star occultation measurements for space navigation and the determination of a horizon density profile which could be used to update atmospheric models for horizon-based measurement systems were studied. The time of occultation of a known star by a celestial body, as seen by an orbiting observer, determines a cylinder of position, the axis of which is the line through the star and the body center, and the radius of which is equal to the occulting-body radius. The dimming percentage, with respect to the altitude of this grazing ray from the star to the observer, is a percentage altitude for occultation. That is, the star can be assumed to be occulted when it reaches a predetermined percentage of its unattenuated value. The procedure used was to measure this attenuation with respect to time to determine the usefulness of the measurements for autonomous space navigation. In this experiment, the crewmembers had to accomplish star acquisition, identification, calibration, and tracking. Instrumentation was required only for measurement of the relative intensity of the star as it set into the atmosphere.

  3. First Stellar Occultation Observation with SOFIA

    NASA Astrophysics Data System (ADS)

    Dunham, Edward W.; Bida, T.; Bosh, A.; Collins, P.; Levine, S.; Person, M.; Pfueller, E.; Roeser, H.; Taylor, B.; Wiedemann, M.; Wolf, J.; Zuluaga, C.

    2012-01-01

    We successfully observed the 2011 June 23 UT stellar occultation by Pluto with the High-speed Imaging Photometer for Occultations (HIPO) instrument from Lowell Observatory and the Fast Diagnostic Camera (FDC) from the Deutches SOFIA Institut (DSI) mounted on the SOFIA telescope. A major prediction astrometry effort focused at MIT combined with the willingness of the SOFIA project to entertain the idea of an in-flight change to the flight plan allowed us to target the center of the occultation shadow. This was accomplished by means of an in-flight prediction update by satellite telephone and a real-time onboard flight plan modification to accommodate the prediction update. We obtained excellent results with both channels of HIPO and the FDC with each light curve showing a small, extended brightening while the star was occulted. We will discuss analysis results as well as SOFIA's considerable potential for future occultation work. We thank the SOFIA program for its willingness to attempt this challenging observation at such an early stage of SOFIA science operations. Lowell's SOFIA work was supported by a grant from USRA, MIT's prediction work was supported by the NASA Planetary Astronomy Program and the National Science Foundation, and the FDC work was supported by the DSI. We thank the US Naval Observatory Flagstaff Station for allowing us to use their facilities to obtain our prediction astrometry observations.

  4. Earth rotation derived from occultation records

    NASA Astrophysics Data System (ADS)

    Sôma, Mitsuru; Tanikawa, Kiyotaka

    2016-04-01

    We determined the values of the Earth's rotation parameter, ΔT = T T - UT, around AD 500 after confirming that the value of the tidal acceleration, dot{n}, of the lunar motion remained unchanged during the period between ancient times and the present. For determining of ΔT, we used contemporaneous occultations of planets by the Moon. In general, occultation records are not useful. However, there are some records that give us a stringent condition for the range of ΔT. Records of the lunar occultations in AD 503 and AD 513 are such examples. In order to assure the usefulness of this occultation data, we used contemporaneous annular and total solar eclipses, which have not been used in the preceding work. This is the first work in which the lunar occultation data have been used as primary data to determine the value of ΔT together with auxiliary contemporaneous annular and total solar eclipses. Our ΔT value is less than a smoothed value (Stephenson 1997) by at least 450 s. The result is consistent with our earlier results obtained from solar eclipses.

  5. General Information about Metastatic Squamous Neck Cancer with Occult Primary

    MedlinePlus

    ... with Occult Primary Treatment (PDQ®)–Patient Version General Information About Metastatic Squamous Neck Cancer with Occult Primary ... the PDQ Adult Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

  6. Occult primary, version 3.2014.

    PubMed

    Ettinger, David S; Handorf, Charles R; Agulnik, Mark; Bowles, Daniel W; Cates, Justin M; Cristea, Mihaela; Dotan, Efrat; Eaton, Keith D; Fidias, Panagiotis M; Gierada, David; Gilcrease, G Weldon; Godby, Kelly; Iyer, Renuka; Lenzi, Renato; Phay, John; Rashid, Asif; Saltz, Leonard; Schwab, Richard B; Shulman, Lawrence N; Smerage, Jeffrey B; Stevenson, Marvaretta M; Varadhachary, Gauri R; Zager, Jonathan S; Zhen, Weining Ken; Bergman, Mary Anne; Freedman-Cass, Deborah A

    2014-07-01

    The NCCN Guidelines for Occult Primary tumors provide recommendations for the evaluation, workup, management, and follow-up of patients with occult primary tumors (cancers of unknown primary). These NCCN Guidelines Insights summarize major discussion points of the 2014 NCCN Occult Primary panel meeting. The panel discussed gene expression profiling (GEP) for the identification of the tissue of origin and concluded that, although GEP has a diagnostic benefit, a clinical benefit has not been demonstrated. The panel recommends against GEP as standard management, although 20% of the panel believes the diagnostic benefit of GEP warrants its routine use. In addition, the panel discussed testing for actionable mutations (eg, ALK) to help guide choice of therapy, but declined to add this recommendation. PMID:24994917

  7. Occult chemical deposition to a Maritime forest

    SciTech Connect

    Vong, R.J.; Kowalski, A.S.

    1996-12-31

    Studies of chemical fluxes from the atmosphere to vegetated surfaces have suggested that, along with conventional wet and dry processes, an additional chemical input occurs when wind-blown cloud droplets are directly intercepted by vegetation. This cloud water deposition process has been sometimes termed {open_quote}occult deposition{close_quote} because the water fluxes cannot ordinarily be observed using rain gauges. Such occult deposition of cloud water has rarely been measured directly, in part because of the complexity of the governing turbulent transfer process. However, reviews by the National Acidic Precipitation Assessment Program (NAPAP SoS/T-2,6) have suggested that the chemical flux to be forest decline in the eastern USA. This paper presents direct field measurements occult chemical fluxes to a silver fir forest located in complex terrain on the Olympic Peninsula near the coast of Washington State, USA.

  8. Close Double Stars from Occultation Video Recordings

    NASA Astrophysics Data System (ADS)

    Waring Dunham, David; George, Anthony; Loader, Brian; Herald, David Russell

    2015-08-01

    Astronomers around the world, both amateur and professional, have been recording lunar and asteroidal occultations of close double stars during the past several years using inexpensive but quite sensitive video cameras that are now available. Several new double stars have been discovered, and the parameters of many close systems have been determined. Besides rather good measurements of the relative magnitudes of the components, the actual separations and position angles can be measured if observations of the same event are made from two or more separate stations. These observations collected by the International Occultation Timing Association (IOTA) are published in the Journal of Double Star Observations. Recently, IOTA has encouraged the observation of occultations of stars in the Kepler 2 program, which is interested in data about close duplicity that affects their analyses for exoplanet transits.

  9. Strong scintillations during atmospheric occultations Theoretical intensity spectra. [radio scattering during spacecraft occultations by planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Hinson, D. P.

    1986-01-01

    Each of the two Voyager spacecraft launched in 1977 has completed a reconnaissance of the Jovian and Saturnian systems. In connection with occultation experiments, strong scintillations were observed. Further theoretical work is required before these scintillations can be interpreted. The present study is, therefore, concerned with the derivation of a theory for strong scattering during atmospheric occultation experiments, taking into account as fundamental quantity of interest the spatial spectrum (or spectral density) of intensity fluctuations. Attention is given to a theory for intensity spectra, and numerical calculations. The new formula derived for Phi-i accounts for strong scattering of electromagnetic waves during atmospheric occultations.

  10. TAOS: The Taiwanese-American Occultation Survey

    NASA Astrophysics Data System (ADS)

    Alcock, C.; Dave, R.; Giammarco, J.; Goldader, J.; Lehner, M.; King, S.-K.; Lee, T.; Wang, A.; Wang, S.-Y.; Wen, C.-Y.; Chen, W. P.; Cook, K.; Marshall, S.; Porrata, R.; Byun, Y.-I.; de Pater, I.; Rice, J.; Lissauer, J.

    2003-06-01

    The Taiwanese-American Occultation Survey (TAOS) seeks to determine the number and size spectrum for small (~3 km) bodies in the Kuiper Belt. This will be accomplished by searching for the brief occultations of bright stars (R~14) by these objects. We have designed and built a special purpose photometric monitoring system for this purpose. TAOS comprises four 50 cm telescopes, each equipped with a 2048×2048 pixel CCD camera, in a compact array located in the central highlands of Taiwan. TAOS will monitor up to 3,000 stars at 5 Hz. The system will go into scientific operation at the end of 003.

  11. TAOS - The Taiwanese-American Occultation Survey

    NASA Astrophysics Data System (ADS)

    Lehner, M. J.; Alcock, C.; Axelrod, T.; Bianco, F.; Byun, Y.-I.; Chen, W.-P.; Cook, K. H.; Dave, R.; de Pater, I.; Giammarco, J.; King, S.-K.; Lee, T.; Lissauer, J.; Marshall, S. L.; Mondal, S.; Nihei, T.; Rice, J.; Schwamb, M.; Wang, A.; Wang, S.-Y.; Wen, C.-Y.; Zhang, Z.-W.

    2006-09-01

    The Taiwanese-American Occultation Survey (TAOS) seeks to determine the number and size spectrum for small (˜3 km) bodies in the Kuiper Belt. This will be accomplished by searching for the brief occultations of bright stars (R˜14) by these objects. We have designed and built a special purpose photometric monitoring system for this purpose. TAOS comprises four 50 cm telescopes, each equipped with a 2048×2048 pixel CCD camera, in a compact array located in the central highlands of Taiwan. TAOS will monitor up to 2 000 stars at 5 Hz. The system went into scientific operation in the autumn of 2005.

  12. Altimetry Using GPS-Reflection/Occultation Interferometry

    NASA Technical Reports Server (NTRS)

    Cardellach, Estel; DeLaTorre, Manuel; Hajj, George A.; Ao, Chi

    2008-01-01

    A Global Positioning System (GPS)- reflection/occultation interferometry was examined as a means of altimetry of water and ice surfaces in polar regions. In GPS-reflection/occultation interferometry, a GPS receiver aboard a satellite in a low orbit around the Earth is used to determine the temporally varying carrier- phase delay between (1) one component of a signal from a GPS transmitter propagating directly through the atmosphere just as the GPS transmitter falls below the horizon and (2) another component of the same signal, propagating along a slightly different path, reflected at glancing incidence upon the water or ice surface.

  13. Technique for 3-Dimesional (3D) Modeling of Osteoarticular Medial Femoral Condyle Vascularized Grafting to Replace the Proximal Pole of Unsalvagable Scaphoid Nonunions.

    PubMed

    Houdek, Matthew T; Matsumoto, Jane M; Morris, Jonathan M; Bishop, Allen T; Shin, Alexander Y

    2016-09-01

    This study describes a novel technique for the preoperative surgical planning for an osteoarticular medial femoral condyle (MFC) graft to replace the proximal pole of a scaphoid. In cases of proximal pole scaphoid nonunion or in Preiser disease, fragmentation of the articular surface can occur, leading to significant pain and disability. Osteoarticular MFC bone grafting can be used to treat these injuries by providing a vascularized osteoarticular surface. Using 3-dimensional imaging and printing we are able to precisely model the injured scaphoid, and also accurately plan the harvest of MFC osteoarticular graft. This technique allows for accurate preoperative planning of a complex 3-dimensional bone, and has improved our execution of the plan intraoperatively. PMID:27466049

  14. The length and position of the long axis of the scaphoid measured by analysis of three-dimensional reconstructions of computed tomography images.

    PubMed

    Guo, Y; Tian, G L

    2011-02-01

    We established the maximum length and the position of the long axis of the scaphoid from three-dimensional reconstructions of spiral computed tomography in 30 pairs of wrists. The distance between two points on the three-dimensional scaphoid surface model were calculated using commercially available software and corresponding coordinates of the two points were documented. The mean length was 29.3 (SD 1.6) mm for men and 26.6 (SD 1.8) mm for women. The location of the distal point was at the centre of the scaphoid tuberosity, with the proximal point of the long axis located at the dorsal ridge of the scapholunate facet. PMID:20732928

  15. Occult gunshot injury of the temporal bone.

    PubMed Central

    Geary, U M; Ritchie, D A; Luke, L C

    1997-01-01

    Increasing firearms violence has produced much public disquiet in recent months and Liverpool has seen a particularly well publicized spate of shootings. This is a case report of an initially occult intracranial injury which illustrates the unpredictable nature of missile trauma and the importance of computerised tomography in all cases of gunshot injury to the head. Images Figure 1 Figure 2 PMID:9193993

  16. Photon counts from stellar occultation sources

    NASA Technical Reports Server (NTRS)

    Buglia, James J.

    1987-01-01

    The feasibility of using stars as radiation sources for Earth atmospheric occultation experiments is investigated. Exoatmospheric photon counts of the order of 10 to the 6th power photons/sq cm/sec are realized for the 15 visually brightest stars. Most photon counts appear to be marginally detectable unless photomultiplier or cascade detection devices can be used.

  17. Occult spondyloarthritis in inflammatory bowel disease.

    PubMed

    Bandinelli, Francesca; Manetti, Mirko; Ibba-Manneschi, Lidia

    2016-02-01

    Spondyloarthritis (SpA) is a frequent extra-intestinal manifestation in patients with inflammatory bowel disease (IBD), although its real diffusion is commonly considered underestimated. Abnormalities in the microbioma and genetic predisposition have been implicated in the link between bowel and joint inflammation. Otherwise, up to date, pathogenetic mechanisms are still largely unknown and the exact influence of the bowel activity on rheumatic manifestations is not clearly explained. Due to evidence-based results of clinical studies, the interest on clinically asymptomatic SpA in IBD patients increased in the last few years. Actually, occult enthesitis and sacroiliitis are discovered in high percentages of IBD patients by different imaging techniques, mainly enthesis ultrasound (US) and sacroiliac joint X-ray examinations. Several diagnostic approaches and biomarkers have been proposed in an attempt to correctly classify and diagnose clinically occult joint manifestations and to define clusters of risk for patient screening, although definitive results are still lacking. The correct recognition of occult SpA in IBD requires an integrated multidisciplinary approach in order to identify common diagnostic and therapeutic strategies. The use of inexpensive and rapid imaging techniques, such as US and X-ray, should be routinely included in daily clinical practice and trials to correctly evaluate occult SpA, thus preventing future disability and worsening of quality of life in IBD patients. PMID:26354428

  18. Illinois occultation summary, 1. 1977 - 1978

    NASA Technical Reports Server (NTRS)

    Radick, R.; Lien, D.

    1980-01-01

    Instrumentation and data acquisition techniques used to record lunar occultations at the University of Illinois Prairie Observatory are described. Tables and graphs summarize data from 64 events which include 30 observations of stars brighter than 7th magnitude, 40 reappearances, 4 angular diameter measurements, 8 observations of binary stars, and 6 observations which may indicate multiplicity.

  19. The Transneptunian Automated Occultation Survey (TAOS II)

    NASA Astrophysics Data System (ADS)

    Lehner, M. J.; Wang, S.-Y.; Ho, P.; Lee, T.; Zhang, Z.-W.; Yen, W.-L.; Reyes Ruiz, M.; Hiriart, D.; Granados, A. P.; Torres, S.; Alcock, C.; Szentgyorgyi, A.; Geary, J. C.; Norton, T.; Furesz, G.

    2012-05-01

    TAOS II is a successor survey to TAOS. TAOS II will measure the size distribution of KBOs by detecting and characterizing their occultations of distant stars. TAOS II will operate 3 1.3 m telescopes at San Pedro Martir Obsevatory in Mexico.

  20. Is It a Simple Stress Fracture or Bisphosphonate-related Atypical Fracture?

    PubMed

    Kang, Soo Yong; Baek, Ji-Hoon; Kang, Bun Jung; Kim, Min Kyu; Lee, Han-Jun

    2012-11-01

    A number of reports regarding atypical fractures of the femur have raised questions concerning the possible correlation between long-term bisphosphonate treatment and the occurrence of insufficiency fractures in the proximal femur. However, clinically, it is often confused whether is it a fatigue fracture because of implant induced stress concentration or a bisphosphonate-related atypical fracture, especially in a patient with a subtrochanteric fracture who receive bisphosphonate therapy after open reduction and internal fixation, such as dynamic hip screw (DHS) fixation for previous ipsilateral femoral neck or intertrochanteric fracture. The authors experienced a case of a progressive femoral insufficiency fracture in a woman who had been on Fosamax (Alendronic acid with Vitamin D; Merck & Co. Inc, NJ, USA) therapy for four years after ipsilateral femoral neck fracture treated with a two hole DHS system. Despite a high suspicion of an insufficiency femoral subtrochanteric fracture by bone scan, the occult fracture progressed to a displaced femoral subtrochanteric fracture one year after. The fracture site was fixed with a 6 hole DHS plate, and six months after reoperation the patient had no symptoms and the fracture site had united without any complication. PMID:24524043

  1. Scaphoid excision and 4-corner fusion using retrograde headless compression screws.

    PubMed

    Ball, Brandon; Bergman, Joseph W

    2012-12-01

    Scapholunate advanced collapse is a predictable form of wrist arthritis resulting from longstanding scapholunate instability. Four-corner fusion and scaphoid excision is a reliable procedure used to treat scapholunate advanced collapse wrist that improves pain and preserves range of motion. Multiple methods of achieving fixation have been described for the procedure including K-wires, staples, and headless compression screws. In previously described techniques, the compression screws are inserted in an antegrade manner, breaching the articular surface of the lunate. Even small areas of chondral damage may undermine the long-term durability of the radiocarpal joint. Given the 4-corner fusion relies on the integrity of the radiolunate articulation for success, it would seem advantageous to preserve the articular cartilage of the lunate. The technique described here involves retrograde insertion of headless compression screws to achieve a 4-corner fusion. Although it is still early, we anticipate that this procedure will result in similar fusion rates to other forms of fixation. PMID:23160552

  2. Preliminary Results From the Champ Occultation Measurements

    NASA Astrophysics Data System (ADS)

    Hajj, G.; Dong, D.; Iijima, B.; Kuang, D.; Kursinski, R.; Mannucci, A.; Meehan, T.; Romans, L.; de la Torre Juárez, M.; Yunck, T.

    2001-05-01

    Champ collects 200-250 globally distributed GPS occultations every day providing a wealth of information on atmospheric parameters such as pressure, temperature, humidity between 0-60 km altitude and electron density above 60 km altitude. There are several aspects to the Champ occultation measurements which distinguish them from prior measurements (such as from GPS/MET, Oersted and SAC-C): (1) They are taken during solar maximum; (2) they are collected with a new generation receiver ("BlackJack") which provides high quality L1 and L2 measurements even when the DoD anti-spoofing of the GPS signal is turned on; (3) the tracking loop in the receiver is optimized to allow the occulted signal to descend very low in the atmosphere (<1km from the surface). A further distinction comes from the fact that selective availability (the dithering of the GPS clocks) was permanently turned off by DoD, therefore reducing or eliminating the need for 1-second ground measurements previously used to difference out high frequency GPS clock drifts. This talk will present results obtained at JPL from the early Champ occultation data sets, first collected in February, 2001, and will address the specific issues listed above. Specifically, we will present (a) statistics on how low in the atmosphere occultations are able to probe as a function of geographical latitudes and humidity conditions; (b) the limitations on higher altitude atmospheric retrievals (between 30-60 km) caused by the ionosphere at different local times and solar conditions, including comparisons to GPS/MET data taken during solar minimum; (c) individual and statistical comparisons of temperature and water vapor to atmospheric analyses such as NCEP and ECMWF and other data sets such as radiosondes; (d) the impact of including or excluding high rate ground data.

  3. Stellar Occultation Probe of Triton's Atmosphere

    NASA Technical Reports Server (NTRS)

    Elliot, James L.

    1998-01-01

    The goals of this research were (i) to better characterize Triton's atmospheric structure by probing a region not well investigated by Voyager and (ii) to begin acquiring baseline data for an investigation of the time evolution of the atmosphere which will set limits on the thermal conductivity of the surface and the total mass of N2 in the atmosphere. Our approach was to use observations (with the Kuiper Airborne Observatory) of a stellar occultation by Triton that was predicted to occur on 1993 July 10. As described in the attached reprint, we achieved these objectives through observation of this occultation and a subsequent one with the KAO in 1995. We found new results about Triton's atmospheric structure from the analysis of the two occultations observed with the KAO and ground-based data. These stellar occultation observations made both in the visible and infrared, have good spatial coverage of Triton including the first Triton central-flash observations, and are the first data to probe the 20-100 km altitude level on Triton. The small-planet light curve model of Elliot and Young (AJ 103, 991-1015) was generalized to include stellar flux refracted by the far limb, and then fitted to the data. Values of the pressure, derived from separate immersion and emersion chords, show no significant trends with latitude indicating that Triton's atmosphere is spherically symmetric at approximately 50 km altitude to within the error of the measurements. However, asymmetry observed in the central flash indicates the atmosphere is not homogeneous at the lowest levels probed (approximately 20 km altitude). From the average of the 1995 occultation data, the equivalent-isothermal temperature of the atmosphere is 47 +/- 1 K and the atmospheric pressure at 1400 km radius (approximately 50 km altitude) is 1.4 +/- 0.1 microbar. Both of these are not consistent with a model based on Voyager UVS and RSS observations in 1989 (Strobel et al, Icarus 120, 266-289). The atmospheric

  4. Transmission profiles from SCIAMACHY solar occultation measurements

    NASA Astrophysics Data System (ADS)

    Zalach, Jacob; Von Savigny, Christian

    Vertical atmospheric transmission profiles contain information about its composition and make it possible to reconstruct the vertical distribution of its components. The measurement of stratospheric aerosol extinction profiles and its size distribution is the goal of the ROMIC-ROSA project for which transmission profiles are the most important precondition. One established method to obtain such profiles are satellite born occultation measurements. For this project SCIAMACHY (EnviSat) solar occultation measurements are analysed. The data set covers a time period of ten years within a wavelength interval between 240 and 2380 nm. Due to different spatial resolution of the measured solar profiles a direct application of existing analysis tools and algorithms is not possible. First they have to be adjusted to the present data. This contribution explains the present data processing and shows the resulting transmission profiles.

  5. The Transneptunian Automated Occultation Survey (TAOS II)

    NASA Astrophysics Data System (ADS)

    Lehner, Matthew J.; Wang, S.; Alcock, C. A.; Cook, K. H.; Furesz, G.; Geary, J. C.; Hiriart, D.; Ho, P. T.; Norton, T.; Reyes-Ruiz, M.; Szentgyorgyi, A.; Yen, W.; Zhang, Z.

    2012-10-01

    The Transneptunian Automated Occultation Survey (TAOS II) will aim to detect occultations of stars by small ( 1 km diameter) objects in the Solar System and beyond. Such events are very rare (<0.001 events per star per year) and short in duration ( 200 ms), so many stars must be monitored at a high readout cadence. TAOS II will operate three 1.3 meter telescopes at the Observatorio Astronómico Nacional at San Pedro Mártir in Baja California, México. With a 2.3 square degree field of view and a high speed camera comprising CMOS imagers, the survey will monitor 10,000 stars simultaneously with all three telescopes at a readout cadence of 20 Hz.

  6. The Transneptunian Automated Occultation Survey (TAOS II)

    NASA Astrophysics Data System (ADS)

    Lehner, Matthew J.; Wang, Shiang-Yu; Alcock, Charles A.; Cook, Kem H.; Furesz, Gabor; Geary, John C.; Hiriart, David; Ho, Paul T.; Lee, William; Melsheimer, Frank; Norton, Timothy; Reyes-Ruiz, Mauricio; Richer, Michael; Szentgyorgyi, Andrew; Yen, Wei-Ling; Zhang, Zhi-Wei

    2012-09-01

    The Transneptunian Automated Occultation Survey (TAOS II) will aim to detect occultations of stars by small ( 1 km diameter) objects in the Solar System and beyond. Such events are very rare (< 10-3 events per star per year) and short in duration ( 200 ms), so many stars must be monitored at a high readout cadence. TAOS II will operate three 1.3 meter telescopes at the Observatorio Astrońomico Nacional at San Pedro Martir in Baja California, Mexico. With a 2.3 square degree field of view and a high speed camera comprising CMOS imagers, the survey will monitor 10,000 stars simultaneously with all three telescopes at a readout cadence of 20 Hz.

  7. Asteroid Sizing by Radiogalaxy Occultation at 5 GHz

    NASA Astrophysics Data System (ADS)

    Lehtinen, K.; Bach, U.; Muinonen, K.; Poutanen, M.; Petrov, L.

    2016-05-01

    Stellar occultations by asteroids observed at visual wavelengths have been an important tool for studying the size and shape of asteroids and for revising the orbital parameters of asteroids. At radio frequencies, a shadow of an asteroid on the Earth is dominated by diffraction effects. Here, we show, for the first time, that a single observation of an occultation of a compact radio source at a frequency of 5 GHz can be used to derive the effective size of the occulting object and to derive the distance between the observer and the center of the occultation path on the Earth. The derived diameter of the occulting object, asteroid (115) Thyra, is 75 ± 6 km. The observed occultation profile shows features that cannot be explained by diffraction of a single asteroid.

  8. CASSINI UVIS STELLAR OCCULTATION OBSERVATIONS OF SATURN's RINGS

    SciTech Connect

    Colwell, J. E.; Jerousek, R. G.; Pettis, D.; Bradley, E. T.; Esposito, L. W.; Sremcevic, M.

    2010-12-15

    The Cassini spacecraft's Ultraviolet Imaging Spectrograph (UVIS) includes a high-speed photometer (HSP) that has observed more than 100 stellar occultations by Saturn's rings. Here, we document a standardized technique applied to the UVIS-HSP ring occultation datasets delivered to the Planetary Data System as higher level data products. These observations provide measurements of ring structure that approaches the scale of the largest common ring particles ({approx}5 m). The combination of multiple occultations at different viewing geometries enables reconstruction of the three-dimensional structure of the rings. This inversion of the occultation data depends on accurate calibration of the data so that occultations of different stars taken at different times and under different viewing conditions can be combined to retrieve ring structure. We provide examples of the structure of the rings as seen from several occultations at different incidence angles to the rings, illustrating changes in the apparent structure with viewing geometry.

  9. The JWST/NIRCam Coronagraph Flight Occulters

    NASA Technical Reports Server (NTRS)

    Krist, John E.; Balasubramanian, Kunjithapatham; Muller, Richard E.; Shaklan, Stuart B.; Kelly, Douglas M.; Wilson, Daniel W.; Beichman, Charles A.; Serabyn, Eugene; Mao, Yalan; Echternach, Pierre M.; Trauger, John T.; Liewer, Kurt M.

    2010-01-01

    The NIRCam instrument on the James Webb Space Telescope will have a Lyot coronagraph for high contrast imaging of extrasolar planets and circumstellar disks at lambda = 2 - 5 micrometers. Half-tone patterns are used to create graded-transmission image plane masks. These are generated using electron beam lithography and reactive ion etching of a metal layer on an antireflection coated sapphire substrate. We report here on the manufacture and evaluation of the flight occulters.

  10. Studies of planetary upper atmospheres through occultations

    NASA Technical Reports Server (NTRS)

    Elliot, J. L.

    1982-01-01

    The structure, composition, dynamics and energy balance of planetary upper atmospheres through interpretation of steller occultation data from Uranus is discussed. The wave-optical problem of modelling strong scintillation for arbitrary turbulent atmospheres is studied, as well as influence of turbulence. It was concluded that quasi-global features of atmospheric structure are accurately determined by numerical inversion. Horizontally inhomogeneous structures are filtered out and have little effect on temperature profiles.

  11. The JWST/NIRCam coronagraph flight occulters

    NASA Astrophysics Data System (ADS)

    Krist, John E.; Balasubramanian, Kunjithapatham; Muller, Richard E.; Shaklan, Stuart B.; Kelly, Douglas M.; Wilson, Daniel W.; Beichman, Charles A.; Serabyn, Eugene; Mao, Yalan; Echternach, Pierre M.; Trauger, John T.; Liewer, Kurt M.

    2010-07-01

    The NIRCam instrument on the James Webb Space Telescope will have a Lyot coronagraph for high contrast imaging of extrasolar planets and circumstellar disks at λ=2 - 5 μm. Half-tone patterns are used to create graded-transmission image plane masks. These are generated using electron beam lithography and reactive ion etching of a metal layer on an antireflection coated sapphire substrate. We report here on the manufacture and evaluation of the flight occulters.

  12. Potential KBO Stellar Occultations: 2011-2015

    NASA Astrophysics Data System (ADS)

    Zangari, Amanda; Zuluaga, C. A.; Gulbis, A. A. S.; Elliot, J. L.; Person, M. J.; Bosh, A. S.

    2010-10-01

    We present the results of an occultation candidate search of the UCAC2 catalog for over 30 Kuiper Belt Objects and Centaurs [not including (134340) Pluto]. KBOs were selected based on absolute magnitude, distance from the sun and the number of oppositions observed. This search identified occultation candidate stars within 2.5 arcseconds of each minor planet's path from 2011-2015. As typical UCAC2 catalog uncertainties ranged from 0.05 to 0.5 arcseconds, and KBO ephemeris uncertainties for a well-observed object ranged from 0.2 to 0.6 arcseconds, this study seeks to identify the most promising potential occultations for further astrometric follow-up. Additional observations of stars and the potentially occulting body help determine the necessary star offsets and ephemeris corrections. Events have been grouped into the following categories: near-geocentric (any brightness), near-misses, stars of magnitude 13 or brighter (the dimmest star feasible with a large portable telescope), slow events, and events observable from telescope-rich regions of the Earth. These categories allow for planning campaigns involving wide-spread portable and fixed telescopes, or an airborne telescope (such as SOFIA). The two most promising events are an encounter of (28978) Ixion with a 10.63 magnitude star on 2012-04-16 and (84922) 2003 VS2 with a 14.83 magnitude star on 2011-11-01. KBOs such as (50000) Quaoar, (28978) Ixion, (55638) 2002 VE95, and (84922) 2003 VS2 encounter over 50 UCAC2 stars in the next five years and should be most carefully monitored. This work was supported, in part by NASA Grant NNX10AB27G.

  13. Evaluation of bone remodeling in regard to the age of scaphoid non-unions

    PubMed Central

    Rein, Susanne; Hanisch, Uwe; Schaller, Hans-Eberhard; Zwipp, Hans; Rammelt, Stefan; Weindel, Stefan

    2016-01-01

    AIM: To analyse bone remodeling in regard to the age of scaphoid non-unions (SNU) with immunohistochemistry. METHODS: Thirty-six patients with symptomatic SNU underwent surgery with resection of the pseudarthrosis. The resected material was evaluated histologically after staining with hematoxylin-eosin (HE), tartrate resistant acid phosphatase (TRAP), CD 68, osteocalcin (OC) and osteopontin (OP). Histological examination was performed in a blinded fashion. RESULTS: The number of multinuclear osteoclasts in the TRAP-staining correlated with the age of the SNU and was significantly higher in younger SNU (P = 0.034; r = 0.75). A higher number of OP-immunoreactive osteoblasts significantly correlated with a higher number of OC-immunoreactive osteoblasts (P = 0.001; r = 0.55). Furthermore, a greater number of OP-immunoreactive osteoblasts correlated significantly with a higher number of OP-immunoreactive multinuclear osteoclasts (P = 0.008; r = 0.43). SNU older than 6 mo showed a significant decrease of the number of fibroblasts (P = 0.04). Smoking and the age of the patients had no influence on bone remodeling in SNU. CONCLUSION: Multinuclear osteoclasts showed a significant decrease in relation to the age of SNU. However, most of the immunhistochemical findings of bone remodeling do not correlate with the age of the SNU. This indicates a permanent imbalance of bone formation and resorption as indicated by a concurrent increase in both osteoblast and osteoclast numbers. A clear histological differentiation into phases of bone remodeling in SNU is not possible. PMID:27458552

  14. Convective towers detection using GPS radio occultations

    NASA Astrophysics Data System (ADS)

    Biondi, R.; Neubert, T.; Syndergaard, S.; Nielsen, J.

    2010-12-01

    The tropical deep convection affects the radiation balance of the atmosphere changing the water vapour mixing ratio and the temperature of the upper troposphere and lower stratosphere. To gain a better understanding of deep convective processes, the study of tropical cyclones could play an important role since they lead to deep convective activity. With this work we want to investigate if severe storms leave a significant signature in radio occultation profiles in the tropical tropopause layer. The GPS radio occultation (RO) technique is useful for studying severe weather phenomena because the GPS signals penetrate through clouds and allow measurements of atmospheric profiles related to temperature, pressure, and water vapour with high vertical resolution. Using tropical cyclone best track database and data from different GPS RO missions (COSMIC, GRACE, CHAMP, SACC and GPSMET), we selected 1194 profiles in a time window of 3 hours and a space window of 300 km from the eye of the cyclone. We show that the bending angle anomaly of a GPS RO signal is typically larger than the climatology above the tropopause. Comparisons with co-located radiosondes, climatology of tropopause altitudes and GOES analyses will also be shown to support our hypothesis and to corroborate the idea that the bending angle anomaly can be used as an indicator of convective towers. The results are discussed in connection to the GPS radio occultation receiver which will be part of the Atomic Clock Ensemble in Space (ACES) payload on the International Space Station.

  15. OCCULT-ORSER complete conversational user-language translator

    NASA Technical Reports Server (NTRS)

    Ramapriyan, H. K.; Young, K.

    1981-01-01

    Translator program (OCCULT) assists non-computer-oriented users in setting up and submitting jobs for complex ORSER system. ORSER is collection of image processing programs for analyzing remotely sensed data. OCCULT is designed for those who would like to use ORSER but cannot justify acquiring and maintaining necessary proficiency in Remote Job Entry Language, Job Control Language, and control-card formats. OCCULT is written in FORTRAN IV and OS Assembler for interactive execution.

  16. Isolated Coronal Fracture of Trapezium- A Case Report with Review of Literature

    PubMed Central

    Panigrahi, Ranajit; Biswal, Manas Ranjan; Palo, Nishit; Panigrahi, Naresh

    2015-01-01

    Introduction: Isolated trapezium fractures accounts for 3-5% of all carpal fractures, are often missed on initial presentation. Trapezial fractures should be treated early given its importance in grip and pinch. We report a rare isolated coronal fracture of trapezium, following fall on an outstretched hand. Case Report: A 40-year-old right lady presented with pain in right hand due to fall on out stretched hand. The radial half of wrist and lower forearm were swollen. Tenderness over trapezium and 1st metacarpal base with terminal thumb movements restricted. X-Ray revealed undisplaced incomplete coronal fracture of the trapezium. CT scan confirmed coronal split fracture of the trapezium with a major volar fragment and a dorsal fragment without articular involvement. The patient refused operative intervention. Fracture was treated conservatively. The follow-up radiographs showed normal articular relationship of the trapezium with the base of first metacarpal and scaphoid. The fracture healed with no complications. Conclusion: Carpal fracture diagnosis requires high clinical suspicion. X-Rays and CT scans define pattern orientation and understanding. PMID:27299062

  17. On the reduction of occultation light curves. [stellar occultations by planets

    NASA Technical Reports Server (NTRS)

    Wasserman, L.; Veverka, J.

    1973-01-01

    The two basic methods of reducing occultation light curves - curve fitting and inversion - are reviewed and compared. It is shown that the curve fitting methods have severe problems of nonuniqueness. In addition, in the case of occultation curves dominated by spikes, it is not clear that such solutions are meaningful. The inversion method does not suffer from these drawbacks. Methods of deriving temperature profiles from refractivity profiles are then examined. It is shown that, although the temperature profiles are sensitive to small errors in the refractivity profile, accurate temperatures can be obtained, particularly at the deeper levels of the atmosphere. The ambiguities that arise when the occultation curve straddles the turbopause are briefly discussed.

  18. Several Well-observed Asteroidal Occultations in 2010

    NASA Astrophysics Data System (ADS)

    Timerson, Brad; Durech, J.; Abramson, H.; Brooks, J.; Caton, D.; Clark, D.; Conard, S.; Cooke, B.; Dunham, D. W.; Dunham, J.; Edberg, S.; Ellington, C.; Faircloth, J.; Herchak, S.; Iverson, E.; Jones, R.; Lucas, G.; Lyzenga, G.; Maley, P.; Martinez, L.; Menke, J.; Mroz, G.; Nolan, P.; Peterson, R.; Preston, S.; Rattley, G.; Ray, J.; Scheck, A.; Stamm, J.; Stanton, R.; Suggs, R.; Tatum, R.; Thomas, W.

    2011-10-01

    During 2010 IOTA observers in North America reported about 190 positive observations for 106 asteroid occultation events. For several asteroids, this included observations with multiple chords. For two events, an inversion model was available. An occultation by 16 Psyche on 2010 August 21 yielded a best-fit ellipse of 235.4 x 230.4 km. On 2010 December 24, an occultation by 93 Minerva produced a best-fit ellipse of 179.4 x 133.4 km. An occultation by 96 Aegle on 2010 October 29 yielded a best-fit ellipse of 124.9 x 88.0 km. An occultation by 105 Artemis on 2010 June 24 showed a best-fit ellipse of 125.0 x 92.0 km. An occultation by 375 Ursula on 2010 December 4 produced a best-fit ellipse of 125.0 km x 135.0 km. Of note are two events not summarized in this article. On 2010 August 31, an occultation by 695 Bella yielded a new double star. That event will be summarized in the JDSO. Finally, on 2010 April 6, an occultation of zeta Ophiuchi by 824 Anastasia was observed by 65 observers at 69 locations. Unfortunately a large shift in the path yielded only 4 chords. Results of that event, and all the events mentioned here, can be found on the North American Asteroidal Occultation Results web page.

  19. Boundary diffraction wave integrals for diffraction modeling of external occulters.

    PubMed

    Cady, Eric

    2012-07-01

    An occulter is a large diffracting screen which may be flown in conjunction with a telescope to image extrasolar planets. The edge is shaped to minimize the diffracted light in a region beyond the occulter, and a telescope may be placed in this dark shadow to view an extrasolar system with the starlight removed. Errors in position, orientation, and shape of the occulter will diffract additional light into this region, and a challenge of modeling an occulter system is to accurately and quickly model these effects. We present a fast method for the calculation of electric fields following an occulter, based on the concept of the boundary diffraction wave: the 2D structure of the occulter is reduced to a 1D edge integral which directly incorporates the occulter shape, and which can be easily adjusted to include changes in occulter position and shape, as well as the effects of sources-such as exoplanets-which arrive off-axis to the occulter. The structure of a typical implementation of the algorithm is included. PMID:22772218

  20. Distal Radius Radiographic Indices and Perilunate Fracture Dislocation

    PubMed Central

    Bagherifard, Abolfazl; Jafari, Davod; Keihan Shokouh, Hassan; Motavallian, Ebrahim; Najd Mazhar, Farid

    2016-01-01

    Background Distal radius radiographic indices may play a role as risk factors in pathogenesis of Kienbock’s disease, scaphoid fracture and nonunion. Perilunate fracture dislocations are devastating wrist injuries, and their relationship and distal radius indices have not been addressed in the literature. Objectives The aim of this study was to evaluate the possible role of distal radius radiographic indices including radial height, radial inclination, ulnar variance and volar tilt as risk factors in the perilunate fracture dislocation injury of the wrist. Patients and Methods We studied distal radius radiographic indices including radial height, radial inclination, ulnar variance and volar tilt in 43 patients with perilunate fracture dislocations and compared them with 44 wrists in the control group. Results The mean values of the radial height, radial inclination, ulnar variance and volar tilt were 12.74 (5 - 18), 24.20 (7 - 35), -0.73 (-5 - 4) and 12.28 (2 - 20) in the patient group. These values were 12.68 (9 - 22), 23.22 (17 - 30), -0.11 (-4 - 3) and 11.05 (-3 - 20), respectively in the control group. There was no statistically significant difference between the two groups. Conclusions This study did not show that distal radius anatomical indices including the radial height, radial inclination, ulnar variance and volar tilt influence perilunate fracture dislocation as risk factors.

  1. Treatment of Scaphoid Waist Nonunion Using Olecranon Bone Graft and Stryker Asnis Micro Cannulated Screw: A Retrospective Study—80 Case Studies and 6 Years of Follow-Up

    PubMed Central

    Poggetti, Andrea; Rosati, Marco; Castellini, Iacopo; Evangelisti, Gisberto; Battistini, Pietro; Parchi, Paolo; Lisanti, Michele

    2015-01-01

    Background Screw fixation and bone grafting are the gold standard for scaphoid waist nonunion without avascular necrosis. Question/Purpose Assesses the scaphoid waist nonunion healing rate with use of an uncommon cancellous bone graft (olecranon) and an unusual fixation system (Asnis Micro Cannulated Screw System; Stryker Inc., Kalamazoo, MI, USA). Material and Methods A series of 102 consecutive patients were treated for scaphoid waist nonunion (without deformity). Of these, 80 patients subjected to clinical (Modified Mayo Wrist Score (MMWS), Jamar hydraulic dynamometer) and radiographic examination before and after surgery were evaluated. Ipsilateral olecranon cancellous bone graft and the ASNIS Micro 3.0-mm diameter screw, were used. The average follow up was 6 years (min 3; max 10). Results Radiographic consolidation was achieved in 90% of patients; dorsal intercalated segment instability (DISI) deformities were corrected in 71.4% of cases. Ninety percent improved the range of motion of the wrist and grip strength. All patients showed a significant reduction of peak force in the operated hand. In 6.25% we observed clinical and radiographic screw head–trapezium impingement. Twenty-six patients developed a degenerative wrist sign. The MMWS yielded 68 optimal, 8 good, and 4 bad results. Conclusions To treat scaphoid waist nonunions without misalignment, low-profile headed screw and olecranon bone graft allowed a high consolidation rate with positive results to long-term follow-up. The Asnis Micro 3.0 mm diameter screw may be a suitable option for treating scaphoid waist nonunion. Level of Evidence IV. PMID:26261746

  2. UMBRAS: a matched occulter and telescope for imaging extrasolar planets

    NASA Astrophysics Data System (ADS)

    Schultz, Alfred B.; Jordan, Ian J.; Kochte, Mark; Fraquelli, Dorothy A.; Bruhweiler, Fred; Hollis, Jan M.; Carpenter, Kenneth G.; Lyon, Richard G.; DiSanti, Mike A.; Miskey, Cherie L.; Leitner, Jesse; Burns, Richard D.; Starin, Scott R.; Rodrigue, Melodi; Fadali, M. S.; Skelton, Dennis L.; Hart, Helen M.; Hamilton, Forrest C.; Cheng, Kwang-Ping

    2003-02-01

    We describe a 1-meter space telescope plus free-flying occulter craft mission that would provide direct imaging and spectroscopic observations of Jovian and Uranus-sized planets about nearby stars not detectable by Doppler techniques. The Doppler technique is most sensitive for the detection of massive, close-in extrasolar planets while the use of a free-flying occulter would make it possible to image and study stellar systems with planets comparable to our own Solar System. Such a mission with a larger telescope has the potential to detect earth-like planets. Previous studies of free-flying occulters reported advantages in having the occulting spot outside the telescope compared to a classical coronagraph onboard a space telescope. Using an external occulter means light scatter within the telescope is reduced due to fewer internal obstructions and less light entering the telescope and the polishing tolerances of the primary mirror and the supporting optics can be less stringent, thereby providing higher contrast and fainter detection limits. In this concept, the occulting spot is positioned over the star by translating the occulter craft, at distances of 1,000 to 15,000 kms from the telescope, on the sky instead of by moving the telescope. Any source within the telescope field-of-view can be occulted without moving the telescope. In this paper, we present our current concept for a 1-m space telescope matched to a free-flying occulter, the Umbral Missions Blocking Radiating Astronomical Sources (UMBRAS) space mission. An UMBRAS space mission consists of a Solar Powered Ion Driven Eclipsing Rover (SPIDER) occulter craft and a matched (apodized) telescope. The occulter spacecraft would be semi-autonomous, with its own propulsion systems, internal power (solar cells), communications, and navigation capability. Spacecraft rendezvous and formation flying would be achieved with the aid of telescope imaging, RF or laser ranging, celestial navigation inputs, and formation

  3. New perspectives in occult hepatitis C virus infection

    PubMed Central

    Carreño, Vicente; Bartolomé, Javier; Castillo, Inmaculada; Quiroga, Juan Antonio

    2012-01-01

    Occult hepatitis C virus (HCV) infection, defined as the presence of HCV RNA in liver and in peripheral blood mononuclear cells (PBMCs) in the absence of detectable viral RNA in serum by standard assays, can be found in anti-HCV positive patients with normal serum levels of liver enzymes and in anti-HCV negative patients with persistently elevated liver enzymes of unknown etiology. Occult HCV infection is distributed worldwide and all HCV genotypes seem to be involved in this infection. Occult hepatitis C has been found not only in anti-HCV positive subjects with normal values of liver enzymes or in chronic hepatitis of unknown origin but also in several groups at risk for HCV infection such as hemodialysis patients or family members of patients with occult HCV. This occult infection has been reported also in healthy populations without evidence of liver disease. Occult HCV infection seems to be less aggressive than chronic hepatitis C although patients affected by occult HCV may develop liver cirrhosis and even hepatocellular carcinoma. Thus, anti-HCV negative patients with occult HCV may benefit from antiviral therapy with pegylated-interferon plus ribavirin. The persistence of very low levels of HCV RNA in serum and in PBMCs, along with the maintenance of specific T-cell responses against HCV-antigens observed during a long-term follow-up of patients with occult hepatitis C, indicate that occult HCV is a persistent infection that is not spontaneously eradicated. This is an updated report on diagnosis, epidemiology and clinical implications of occult HCV with special emphasis on anti-HCV negative cases. PMID:22736911

  4. Occultations by Uranus and Neptune - 1991-1999

    NASA Technical Reports Server (NTRS)

    Klemola, Arnold R.; Mink, Douglas J.

    1991-01-01

    The results of a photographic plate search are presented for stars as faint as mv = 14 which may be occulted by Uranus or Neptune or their rings between January 1, 1991 and December 31, 1999. Circumstances for the closest approach of Uranus to 76 stars and Neptune to 18 stars are presented. Occultations by Neptune's ring 'arcs' are predicted in 1992, 1997, and 1999.

  5. The Treatment of the Occult in General Encyclopedias.

    ERIC Educational Resources Information Center

    Sonnenfeld, Gary F.

    This paper is a content analysis of three general encyclopedias, "Encyclopedia Americana" (EA), "Encyclopaedia Brittanica" (EB), and "World Book Encyclopedia" (WBC), which quantifies the treatment of the occult. Entries are selected from each by starting with the article "Occultism" and tracing all cross-references. Cross-references are likewise…

  6. Asteroidal Occultation by 82 Alkmene and the Inversion Model Match

    NASA Astrophysics Data System (ADS)

    Timerson, Brad; Durech, J.; Beard, T.; McPartlin, C.; Morgan, W.; Schindler, K.; Wolf, J.; Bardecker, J.; Anderson, W.; Arrowsmith, C.; Gimple, B.; Coburn, C.; Hill, H.; Smoot, T.

    2015-04-01

    On 2014 September 18, the asteroid 82 Alkmene occulted HIP 99229 for observers in the western United States. Four well-spaced chords allowed matching these observations with one of the two convex shape models available for this asteroid. Results of this event can be found on the North American Asteroidal Occultation Results webpage.

  7. 21 CFR 864.6550 - Occult blood test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Occult blood test. 864.6550 Section 864.6550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test....

  8. 21 CFR 864.6550 - Occult blood test.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Occult blood test. 864.6550 Section 864.6550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test....

  9. 21 CFR 864.6550 - Occult blood test.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Occult blood test. 864.6550 Section 864.6550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test....

  10. 21 CFR 864.6550 - Occult blood test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Occult blood test. 864.6550 Section 864.6550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test....

  11. 21 CFR 864.6550 - Occult blood test.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Occult blood test. 864.6550 Section 864.6550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6550 Occult blood test....

  12. Retrieval Algorithms for the Halogen Occultation Experiment

    NASA Technical Reports Server (NTRS)

    Thompson, Robert E.; Gordley, Larry L.

    2009-01-01

    The Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS) provided high quality measurements of key middle atmosphere constituents, aerosol characteristics, and temperature for 14 years (1991-2005). This report is an outline of the Level 2 retrieval algorithms, and it also describes the great care that was taken in characterizing the instrument prior to launch and throughout its mission life. It represents an historical record of the techniques used to analyze the data and of the steps that must be considered for the development of a similar experiment for future satellite missions.

  13. Radio occultation experiments with INAF-IRA radiotelescopes.

    NASA Astrophysics Data System (ADS)

    Pluchino, S.; Schillirò, F.; Salerno, E.; Pupillo, G.

    The Radio Occultation research program performed at the Medicina and Noto Radioastronomical Stations of the Istituto Nazionale di Astrofisica (INAF) - Istituto di Radioastronomia (IRA) includes observations of spacecraft by satellite and satellite by satellite events. The Lunar Radio Occultation (LRO) part of the program consists in collecting data of the lunar Total Electron Content (TEC), at different limb longitudes and at different time, in order to study long term variation of the Moon's ionosphere. The LRO program started at Medicina in September 2006 with the observation of the European probe SMART-1 during its impact on the lunar soil. It proceeded in 2007 with the observation of the lunar occultations of Saturn and Venus, and with the observation of Mars in 2008. On this occasion the probes Cassini, Venus Express, Mars Express, Mars Reconaissance Orbiter and Mars Odissey were respectively occulted by the moon. On Dec 1st 2008 a Venus lunar occultation occurred. On that occasion we performed the first Italian-VLBI (I-VLBI) tracking experiment by detecting the carrier signals coming from the Venus Express (VEX) spacecraft with both the IRA radiotelescopes together with the Matera antenna of the Italian Space Agency. The second part of the radio occultation program includes the observation of satellite by satellite occultation events, as well as mutual occultations of Jupiter satellites. These events are referred to as mutual phenomena (PHEMU). These observations are aimed to measure the radio flux variation during the occultation and to derive surface spatial characteristics such as Io's hot spots. In this work preliminary results of the Radio Occultation program will be presented.

  14. Occultations of stars by solar system objects. III - A photographic search for occultations of faint stars by selected asteroids

    NASA Astrophysics Data System (ADS)

    Millis, R. L.; Franz, O. G.; Wasserman, L. H.; Bowell, E.

    1983-02-01

    Occultations of stars fainter than the AGK and SAO catalog limits by selected minor planets during their 1983 apparitions have been identified by scanning plates taken with the 13-in. Lowell astrograph. A total of 33 upcoming occultations have been found involving 1 Ceres, 10 Hygiea, 52 Europa, 65 Cybele, 451 Patientia, 511 Davida, and 704 Interamnia.

  15. Halogen Occultation Experiment (HALOE) optical filter characterization

    NASA Technical Reports Server (NTRS)

    Harvey, Gale A.

    1989-01-01

    The Halogen Occultation Experiment (HALOE) is a solar occultation experiment that will fly on the Upper Atmosphere Research Satellite to measure mixing ratio profiles of O3, H2O, NO2, NO, CH4, HCl, and HF. The inversion of the HALOE data will be critically dependent on a detailed knowledge of eight optical filters. A filter characterization program was undertaken to measure in-band transmissions, out-of-band transmissions, in-band transmission shifts with temperature, reflectivities, and age stability. Fourier Transform Infrared Spectrometers were used to perform measurements over the spectral interval 400/cm to 6300/cm (25 micrometers to 1.6 micrometers). Very high precision (0.1 percent T) in-band measurements and very high resolution (0.0001 percent T) out-of-band measurements have been made. The measurements revealed several conventional leaks at 0.01 percent transmission and greatly enhanced (1,000) leaks to the 2-element filters when placed in a Fabry-Perot cavity. Filter throughput changes by 5 percent for a 25 C change in filter temperature.

  16. Processing GPS Occultation Data To Characterize Atmosphere

    NASA Technical Reports Server (NTRS)

    Hajj, George; Kursinski, Emil; Leroy, Stephen; Lijima, Byron; de la Torre Juarez, Manuel; Romans, Larry; Ao, Chi

    2005-01-01

    GOAS [Global Positioning System (GPS) Occultation Analysis System] is a computer program that accepts signal-occultation data from GPS receivers aboard low-Earth-orbiting satellites and processes the data to characterize the terrestrial atmosphere and, in somewhat less comprehensive fashion, the ionosphere. GOAS is very robust and can be run in an unattended semi-operational processing mode. It features sophisticated retrieval algorithms that utilize the amplitudes and phases of the GPS signals. It incorporates a module that, using an assumed atmospheric refractivity profile, simulates the effects of the retrieval processing system, including the GPS receiver. GOAS utilizes the GIPSY software for precise determination of orbits as needed for calibration. The GOAS output for the Earth s troposphere and mid-to-lower stratosphere consists of high-resolution (<1 km) profiles of density, temperature, pressure, atmospheric refractivity, bending angles of signals, and water-vapor content versus altitude from the Earth s surface to an altitude of 30 km. The GOAS output for the ionosphere consists of electron-density profiles from an altitude of about 50 km to the altitude of a satellite, plus parameters related to the rapidly varying structure of the electron density, particularly in the E layer of the ionosphere.

  17. Faster Processing for Inverting GPS Occultation Data

    NASA Technical Reports Server (NTRS)

    Ao, Chi

    2004-01-01

    A document outlines a computational method that can be incorporated into two prior methods used to invert Global Positioning System (GPS) occultation data [signal data acquired by a low-Earth-orbiting satellite as either this or the GPS satellite rises above or falls below the horizon] to obtain information on altitude-dependent properties of the atmosphere. The two prior inversion methods, known as back propagation and canonical transform, are computationally expensive because for each occultation, they involve numerical evaluation of a large number of diffraction-like spatial integrals. The present method involves an angular-spectrum-based phase-extrapolation approximation in which each data point is associated with a plane-wave component that propagates in a unique direction from the orbit of the receiving satellite to intersect a straight line tangent to the orbit at a nearby point. This approximation enables the use of fast Fourier transforms (FFTs), which apply only to data collected along a straight-line trajectory. The computation of the diffraction-like integrals in the angular-spectrum domain by use of FFTs takes only seconds, whereas previously, it took minutes.

  18. Saturn's shape from Cassini radio occultations

    NASA Astrophysics Data System (ADS)

    Flasar, F.; Schinder, P. J.; French, R. G.; Marouf, E. A.; Kliore, A. J.

    2013-12-01

    We report the shape of Saturn's isobaric surfaces between 0.1 mbar and ~1 bar determined from more than thirty Cassini radio-occultation soundings between 70 S and 60 N. The retrieval of pressure vs. planetary radius requires knowledge of the shape of the atmosphere. To do this, we use the gravitational coefficients given by Jacobson et al. (2006) and the angular velocities at the cloud-top level from the Voyager winds reported by Sanchez-Lavega et al. (2000). To keep the ray-tracing inversions tractable, we assume that the atmosphere is locally axisymmetric and that its angular velocity is a function of the distance from the planetary rotation axis; except for near the equator, the latter is equivalent to assuming that the winds are barotropic. Note that the "barotropic" assumption--which permits the use of a geopotential incorporating both gravity and differential rotation--need only apply in the atmospheric shell probed by the occultations. The retrieved isobaric surfaces show evidence of moderate baroclinicity. For example, the deviations of the 1-bar and 100-mbar surfaces from the geopotential surface assumed in the ray tracing are of order 10-20 km, less than a pressure scale height.

  19. Asteroid occultations today and tomorrow: toward the GAIA era

    NASA Astrophysics Data System (ADS)

    Tanga, P.; Delbo, M.

    2007-11-01

    Context: Observation of star occultations is a powerful tool to determine shapes and sizes of asteroids. This is key information necessary for studying the evolution of the asteroid belt and to calibrate indirect methods of size determination, such as the models used to analyze thermal infrared observations. Up to now, the observation of asteroid occultations is an activity essentially secured by amateur astronomers equipped with small, portable equipments. However, the accuracy of the available ephemeris prevents accurate predictions of the occultation events for objects smaller than ~100 km. Aims: We investigate current limits in predictability and observability of asteroid occultations, and we study their possible evolution in the future, when high accuracy asteroid orbits and star positions (such as those expected from the mission Gaia of the European Space Agency) will be available. Methods: We use a simple model for asteroid ephemeris uncertainties and numerical algorithms for estimating the limits imposed by the instruments, assuming realistic CCD performances and asteroid size distribution, to estimate the expected occultation rate under different conditions. Results: We show that high accuracy ephemerides which will be available in the future will extend toward much smaller asteroids the possibility of observing asteroid occultations, greatly increasing the number of events and objects involved. A complete set of size measurements down to ~10 km main belt asteroids could be obtained in a few years, provided that a small network of ground-based 1m telescopes are devoted to occultation studies.

  20. A Digital Video System for Observing and Recording Occultations

    NASA Astrophysics Data System (ADS)

    Barry, M. A. Tony; Gault, Dave; Pavlov, Hristo; Hanna, William; McEwan, Alistair; Filipović, Miroslav D.

    2015-09-01

    Stellar occultations by asteroids and outer solar system bodies can offer ground based observers with modest telescopes and camera equipment the opportunity to probe the shape, size, atmosphere, and attendant moons or rings of these distant objects. The essential requirements of the camera and recording equipment are: good quantum efficiency and low noise; minimal dead time between images; good horological faithfulness of the image timestamps; robustness of the recording to unexpected failure; and low cost. We describe an occultation observing and recording system which attempts to fulfil these requirements and compare the system with other reported camera and recorder systems. Five systems have been built, deployed, and tested over the past three years, and we report on three representative occultation observations: one being a 9 ± 1.5 s occultation of the trans-Neptunian object 28978 Ixion (m v =15.2) at 3 seconds per frame; one being a 1.51 ± 0.017 s occultation of Deimos, the 12 km diameter satellite of Mars, at 30 frames per second; and one being a 11.04 ± 0.4 s occultation, recorded at 7.5 frames per second, of the main belt asteroid 361 Havnia, representing a low magnitude drop (Δm v = ~0.4) occultation.

  1. The occultation of Kappa Geminorum by Eros. [stellar occultation observed for asteroid size and shape

    NASA Technical Reports Server (NTRS)

    Oleary, B.; Marsden, B. G.; Dragon, R.; Hauser, E.; Mcgrath, M.; Backus, P.; Robkoff, H.

    1976-01-01

    The paper discusses predictions and observations of the occultation of Kappa Gem by (433) Eros on January 24, 1975. Several positive and negative observations made in western New England are described. Local circumstances for the occultation are reconstructed, and the size and shape of Eros are determined analytically as well as graphically. The calculations yield two extremes for the cross section: a circle 23 km in diameter or a somewhat irregular figure 20 km by 6 or 7 km. Arguments based on the expected albedo of the asteroid suggest that the circle should be warped into an ellipse 21 by 13 km or that the irregular figure might be one component of a dumbbell-like profile.

  2. Flight System Implementation of the Spacecraft Occulter System for Theia

    NASA Astrophysics Data System (ADS)

    Tenerelli, Domenick; Theia

    2009-01-01

    The objective of the Theia program is to characterize Earth-like planets around nearby stars. Theia utilizes two formation-flying spacecraft in an L2 orbit - an observatory and a free flying occulter. Characterization involves looking for signs of life by observing molecular signatures and the presence of water vapor. A free flying occulter spacecraft provides starlight suppression by blocking the starlight while allowing planet light to pass. A diffraction limited monolithic optical telescope is provided for observing planet light passed by the occulter spacecraft. The occulter spacecraft and observatory are flown with a separation of 38, 700 km to 72,000 km (depending on telescope aperture). The Theia system design greatly simplifies design, manufacturing, modeling, and testing requirements compared to a stand-alone high performance internal coronagraph. Design advantages include having thermal/mechanical specifications approaching those of a conventional telescope requiring minimal actuator count. Standard materials and manufacturing approaches apply. End-to-end testing and facilities requirements are standard. The occulter is comprised of up to 30 petals constructed of a dimensionally stable material. Each petal is structurally reinforced for ground handling and testing purposes. An electro-mechanically actuated deployment utilizes standard space qualified mechanism designs to achieve up to a 50m deployed diameter. Multiple layers ensure performance over 5 years of micro-meteroid degradation. The occulter spacecraft is a modular design built of dimensionally stable composite material with 6 bays mounted to a propulsion sub-assembly. The occulter spacecraft uses ion thrusters to achieve its required delta-V over its lifetime and to maintain a position tolerance of 1 m with respect to the observatory. A traditional reaction wheel system is used to maintain orientation. The occulter and occulter spacecraft are compatible with the Atlas 5 launch vehicle.

  3. Elbow Fractures

    MedlinePlus

    ... and held together with pins and wires or plates and screws. Fractures of the distal humerus (see ... doctor. These fractures usually require surgical repair with plates and/or screw, unless they are stable. SIGNS ...

  4. Stellar occultations by planetary rings: 3 July 1989 28 SGR occultation by Saturn

    NASA Technical Reports Server (NTRS)

    Porco, Carolyn C.; Hubbard, B.

    1991-01-01

    The near infrared observations of the 3 Jul. 1989 occultation of 28 Sagittarii by Saturn and its rings made from seven different telescopes spread around the world were reduced and synthesized. These observations were combined with Voyager data to study the dynamical state of Saturn's rings. This unique event, which occurred eight years after the Voyager flybys, provides a temporal baseline over which kinematical and dynamical phenomena within the rings may be examined in detail.

  5. The Research and Education Collaborative Occultation Network: A System for Coordinated TNO Occultation Observations

    NASA Astrophysics Data System (ADS)

    Buie, Marc W.; Keller, John M.

    2016-03-01

    We describe a new system and method for collecting coordinated occultation observations of trans-Neptunian objects (TNOs). Occultations by objects in the outer solar system are more difficult to predict due to their large distance and limited span of the astrometric data used to determine their orbits and positions. This project brings together the research and educational community into a unique citizen-science partnership to overcome the difficulties of observing these distant objects. The goal of the project is to get sizes and shapes for TNOs with diameters larger than 100 km. As a result of the system design it will also serve as a probe for binary systems with spatial separations as small as contact systems. Traditional occultation efforts strive to get a prediction sufficiently good to place mobile ground stations in the shadow track. Our system takes a new approach of setting up a large number of fixed observing stations and letting the shadows come to the network. The nominal spacing of the stations is 50 km so that we ensure two chords at our limiting size. The spread of the network is roughly 2000 km along a roughly north-south line in the western United States. The network contains 56 stations that are committed to the project and we get additional ad hoc support from International Occultation Timing Association members. At our minimum size, two stations will record an event while the other stations will be probing the inner regions for secondary events. Larger objects will get more chords and will allow determination of shape profiles. The stations are almost exclusively sited and associated with schools, usually at the 9-12 grade level. We present a full description of the system we have developed for the continued exploration of the Kuiper Belt.

  6. The occultation of HIP 107302 by Jupiter

    NASA Astrophysics Data System (ADS)

    Christou, A. A.; Beisker, W.; Casas, R.; Schnabel, C.; Massallé, A.; Díaz-Martin, M. C.; Assafin, M.; Braga-Ribas, F.; Eppich, P.; Bath, K.-L.; Tsamis, V.; Tigani, K.; Farmakopoulos, A.; Douvris, A.; Liakos, A.; Eberle, A.; Farago, O.

    2013-08-01

    Aims: Occultations of bright stars by planets provide information on the state of their atmospheres. An occultation of the bright star 45 Capricornii (HIP 107302) by Jupiter occurred on the night of 3/4 August 2009. Methods: The event was observed at multiple sites in Europe, Africa and South America and with instruments ranging in aperture from 0.4 m to 2.2 m. All observations, except one, were carried out in methane absorption bands centred at 0.89 μm and 2.2 μm to minimise the planetary contribution to the measured stellar flux. Following the application of special post-processing techniques, differential photometry was performed. Nearby bright satellites were used as reference sources. Results: Fifteen lightcurves were obtained. The photometric time series for fourteen of these were fitted to a model atmosphere of constant scale height (H). Estimates of H for most lightcurves lie within the range 20-30 km with an inverse-variance weighted mean of 23.6 ± 0.4 km, in good agreement with previous works. A comparison between half-light times at ingress and at egress implies an astrometric offset of 10-15 mas in Jupiter's position relative to the star. Five lightcurves - two for ingress and three for egress - were numerically inverted into profiles of pressure versus temperature. Isothermal, mutually consistent behaviour is observed within the pressure range 3-10 μbar. The inferred temperature of 165 ± 5 K is consistent with, but slightly higher than, that measured by the Galileo Probe at 5° S latitude in 1995 at the same pressure level. Subtraction of isothermal models for nine cases show the presence of at least one, and possibly two, non-isothermal layers a few tens of km below the half-light datum. Their altitudes are similar to those of features previously reported during the occultation of HIP 9369 in 1999. Our temperature estimates are consistent with the expected small magnitude of the perturbation of the atmosphere following the impact event on Jupiter

  7. Variability in Saturn's upper atmosphere from Cassini/UVIS occultations

    NASA Astrophysics Data System (ADS)

    Koskinen, T. T.; Strobel, D. F.; West, R. A.; Yelle, R. V.

    2015-10-01

    We present new density and temperature profiles based on more than 20 stellar occultations by Saturn's upper atmosphere observed simultaneously by the EUV and FUV channels of the Cassini/UVIS instrument. With these results, more than 40 stellar and solar occultations from Cassini/UVIS [1, 2, 3] and 6 occultations from Voyager/UVS [4] have now been analyzed. The results provide valuable constraints on models of chemistry, dynamics and thermal structure in the upper atmosphere. They are also required to plan for the end of the Cassini mission.

  8. Occultations by Pluto and Charon - 1990-1999

    NASA Technical Reports Server (NTRS)

    Mink, Douglas J.; Klemola, Arnold R.; Buie, Marc W.

    1991-01-01

    The results of a photographic plate search for stars as faint as V = 16 which may be occulted by Pluto or Charon between January 1, 1990 and December 31, 1999 are presented. Circumstances for the closest approach of Pluto to 32 stars and Charon to 28 stars are presented. Photometric information is given for some of the brightest stars found in a search of the Space Telescope Guide Star Catalog for Pluto occultations. Finding charts from Space Telescope Guide Star plates are provided for some of the best events. The brightest star (V = 12.7) may be occulted by both Pluto and Charon on September 26, 1999.

  9. CT detection of occult pneumothorax in head trauma

    SciTech Connect

    Tocino, I.M.; Miller, M.H.; Frederick, P.R.; Bahr, A.L.; Thomas, F.

    1984-11-01

    A prospective evaluation for occult pneumothorax was performed in 25 consecutive patients with serious head trauma by combining a limited chest CT examination with the emergency head CT examination. Of 21 pneuomothoraces present in 15 patients, 11 (52%) were found only by chest CT and were not identified clinically or by supine chest radiograph. Because of pending therapeutic measures, chest tubes were placed in nine of the 11 occult pneumothoraces, regardless of the volume. Chest CT proved itself as the most sensitive method for detection of occult pneumothorax, permitting early chest tube placement to prevent transition to a tension pneumothorax during subsequent mechanical ventilation or emergency surgery under general anesthesia.

  10. Olecranon Fractures.

    PubMed

    Brolin, Tyler J; Throckmorton, Thomas

    2015-11-01

    Olecranon fractures are common upper extremity injuries, with all but nondisplaced fractures treated surgically. There has been a recent shift in the surgical management of these fractures from tension band wiring to locking plate fixation and intramedullary nailing; however, this comes with increased implant cost. Although most patients can expect good outcomes after these various techniques, there is little information to guide a surgeon's treatment plan. This article reviews the epidemiology, classification, treatment, and outcomes of olecranon fractures. PMID:26498547

  11. Theory of radio occultation by Saturn's rings

    NASA Technical Reports Server (NTRS)

    Marouf, E. A.; Tyler, G. L.; Eshleman, V. R.

    1982-01-01

    The radio occultation technique, as applied to Saturn's rings, is developed as a new method for the study of the physical properties of planetary ring systems. The rings are treated as a Doppler-spread radar target composed of an ensemble of discrete scatterers. The mathematical formulation of the received signal as a random-phasor-sum process is carried out following a conventional radar theory approach, providing a convenient starting point for deriving coherent signal parameters. A classical result is rederived for the equivalent refractive index of the medium. The analysis is generalized to include ringlets of arbitrary width and it is shown that when the width is such that two adjacent rays are differentially perturbed in phase, ray bending that causes focusing of the coherent signal may result. The diffuse component is also treated in detail.

  12. Halogen occultation experiment intergrated test plan

    NASA Technical Reports Server (NTRS)

    Mauldin, L. E., III; Butterfield, A. J.

    1986-01-01

    The test program plan is presented for the Halogen Occultation Experiment (HALOE) instrument, which is being developed in-house at the Langley Research Center for the Upper Atmosphere Research Satellite (UARS). This comprehensive test program was developed to demonstrate that the HALOE instrument meets its performance requirements and maintains integrity through UARS flight environments. Each component, subsystem, and system level test is described in sufficient detail to allow development of the necessary test setups and test procedures. Additionally, the management system for implementing this test program is given. The HALOE instrument is a gas correlation radiometer that measures vertical distribution of eight upper atmospheric constituents: O3, HC1, HF, NO, CH4, H2O, NO2, and CO2.

  13. Profiling Saturn's rings by radio occultation

    SciTech Connect

    Marouf, E.A.; Tyler, G.L.; Rosen, P.A.

    1986-10-01

    The development of reconstruction algorithms that correct for diffraction effects in radio occultation measurements is described. The reciprocal Fresnel transform relationship between the complex amplitude of the observed coherent signal and the complex microwave transmittance of the rings is derived using the Huygens-Fresnel formulation of the diffraction problem. The effects of the finite data segment width, the uncertainties in the Fresnel scale, systematic phase errors in the kernel of the inverse transform, reference oscillator instabilities, and random noise measurements on the resolution of the reconstructed transmittance are analyzed. Examples of reconstructed opacity profiles for some regions of Saturn's rings derived by applying the reconstruction theory to Voyager 1 at Saturn data are presented. 35 references.

  14. Profiling Saturn's rings by radio occultation

    NASA Technical Reports Server (NTRS)

    Marouf, Essam A.; Tyler, G. Leonard; Rosen, Paul A.

    1986-01-01

    The development of reconstruction algorithms that correct for diffraction effects in radio occultation measurements is described. The reciprocal Fresnel transform relationship between the complex amplitude of the observed coherent signal and the complex microwave transmittance of the rings is derived using the Huygens-Fresnel formulation of the diffraction problem. The effects of the finite data segment width, the uncertainties in the Fresnel scale, systematic phase errors in the kernel of the inverse transform, reference oscillator instabilities, and random noise measurements on the resolution of the reconstructed transmittance are analyzed. Examples of reconstructed opacity profiles for some regions of Saturn's rings derived by applying the reconstruction theory to Voyager 1 at Saturn data are presented.

  15. Pluto Stellar Occultation on 2008 Aug 25

    NASA Astrophysics Data System (ADS)

    Buie, Marc W.; Young, L. A.; Young, E. F.; Olkin, C. B.; Terrell, D.; Parker, J. W.; Durda, D.; Stansberry, J. A.; Reitsema, H.; French, R. G.; Shoemaker, K.; Brown, M. E.; Schaller, E. L.; Bauer, J. M.; Young, J. W.; Wasserman, L. H.; Pasachoff, J. M.; Lust, N.; Fernandez, Y. R.; Dellinger, J. A.; Garossino, P. G. A.; Grigsby, B.; Stone, R. P. S.; Dillon, W. G.; Mezzalira, F.; Ryan, E. V.; Ryan, W.; Souza, S. P.; Williams, R.; Sexton, C.

    2009-01-01

    We report on a successful occultation of a star by Pluto that was observable over much of the south and western United States. The centerline was close to WIRO. We will present seven complete lightcurves from Crossley/Lick, WIRO, SBO/CU, Palomar, JPL/TMO, Sierra Stars Obs., and Magdalena Ridge Observatory. We have 2 partial lightcurves from Lowell Obs. and McDonald Obs. where data loss was caused by clouds. There were attempts at the Steward 90", George Observatory, and New Mexico Skies that were clouded out. The UCF station near Orlando was clearly an appulse. A number of other amateurs also succeeded in collecting data. Our presentation will provide a final geometric solution for the event as well as baseline fits to the atmospheric structure. This work was supported by NASA Planetary Astronomy grants NNX08AO626 and NNX08AO50G.

  16. Paraneoplastic retinopathy associated with occult bladder cancer.

    PubMed

    Nivean, M; Muttuvelu, Danson V; Afzelius, Pia; Berman, Dalia C

    2016-03-01

    The aim was to report the first case of cancer-associated retinopathy (CAR) presenting before bladder cancer diagnosis. A 71-year-old woman with a history of bilateral vision loss underwent subsequent complete ophthalmic examination include a fluorescein angiography, full-field electroretinogram (ERG), serology including serum antibodies for CAR, and positron emission tomography-computed tomography (PET-CT) scan. The patient was diagnosed with bladder carcinoma revealed by PET-CT. Timely recognition of this entity may be crucial for an increased patient survival thus adult onset progressive photoreceptor dysfunction, confirmed by ERG, should alert to a possible remote effect of known or occult malignancy. In the latter, PET-CT may be exploited as a powerful diagnostic tool. PMID:27146943

  17. Paraneoplastic retinopathy associated with occult bladder cancer

    PubMed Central

    Nivean, M; Muttuvelu, Danson V; Afzelius, Pia; Berman, Dalia C

    2016-01-01

    The aim was to report the first case of cancer-associated retinopathy (CAR) presenting before bladder cancer diagnosis. A 71-year-old woman with a history of bilateral vision loss underwent subsequent complete ophthalmic examination include a fluorescein angiography, full-field electroretinogram (ERG), serology including serum antibodies for CAR, and positron emission tomography-computed tomography (PET-CT) scan. The patient was diagnosed with bladder carcinoma revealed by PET-CT. Timely recognition of this entity may be crucial for an increased patient survival thus adult onset progressive photoreceptor dysfunction, confirmed by ERG, should alert to a possible remote effect of known or occult malignancy. In the latter, PET-CT may be exploited as a powerful diagnostic tool. PMID:27146943

  18. Intensity Scintillations in Planetary Ring Occultations: Simulations

    NASA Astrophysics Data System (ADS)

    Marouf, E.

    2003-12-01

    A combined analytical and numerical simulation approach is used to investigate the first, second, and fourth statistical averages of the signal observed during a ring occultation experiment. The rings are modeled as a randomly blocked diffraction screen. The field behind the screen (the rings) assumes binary values: zero if located in the shadow area cast by ring particles and the full incident field otherwise. The stochastic geometry of the union of shadow areas cast behind the rings defines a so-called Boolean model. Either the random wavefront formed behind the screen or it's statistical averages can be propagated to an observer (a detector) some distance away from the diffraction screen. The parabolic approximation of the wave equation is used to model near-forward diffraction effects over the free-space path from the ring plane to the observation plane. The first and second moments were previously shown to correspond to the well-known coherent and scattered signal components observed during radio occultation experiments. Of particular interest here is the fourth moment of the random field at the observer, which determines the intensity scintillation index. Numerical simulations are used to investigate its behavior as a function of relevant model parameters, in particular, the ring particle radius and the Fresnel scale of observation. A monodispersion of ring particles is assumed to keep the model as simple as possible so as to investigate conditions under which the particle size may be recoverable from the intensity scintillation measurements. The model is also idealized to one-dimensional diffraction screen in order to speed up the computations; however, simulations of the more realistic two-dimensional diffraction screen models are also carried out.

  19. Occult Cranial Cervical Dislocation: A Case Report and Brief Literature Review

    PubMed Central

    Shatsky, Joshua B.; Alton, Timothy B.; Bellabarba, Carlo

    2016-01-01

    Study Design. Retrospective case report and review. Objective. Cranial cervical dislocation (CCD) is commonly a devastating injury. Delay in diagnosis has been found to lead to worse outcomes. Our purpose is to describe a rare case of occult cranial cervical dislocation (CCD) and use it to highlight key clinical and radiographic findings to ensure expedited diagnosis and proper management avoiding delays and subsequent neurologic deterioration. Method. Case report with literature review. Results. We describe a unique case of occult cranial cervical dislocation where initial imaging of the cervical spine failed to illustrate displacement of the occipital-cervical (O-C1) articulation or C1-C2 articulation. Careful evaluation of subtle radiographic clues suggested a more severe injury than initial review. Additional imaging was obtained due to these subtle clues confirming true cranial cervical dislocation allowing subsequent treatment with no neurologic sequelae. Conclusion. A high index of suspicion of CCD may prevent injury in select patients who present without gross cord compromise. Careful consideration of associated fractures, soft tissue injuries, and mechanism of injury are essential clues to the correct diagnosis and management of injuries to the craniocervical junction (CCJ). PMID:27366337

  20. Occultations of stars by solar system objects. V - A photographic search for occultations by selected asteroids in 1984

    NASA Technical Reports Server (NTRS)

    Millis, R. L.; Wasserman, L. H.; Franz, O. G.; Bowell, E.; Klemola, A.

    1984-01-01

    Photographic plates taken with the 0.5-m Carnegie double astrograph have been used to identify upcoming asteroid occultations not found in earlier star catalog searches. Twenty-six occultations involving the minor planets 1 Ceres, 10 Hygiea, 52 Europa, 65 Cybele, 451 Patientia, 511 Davida, and 704 Interamnia were found in this search. Of particular interest is the occultation of BD + 8 deg 471 by 1 Ceres on November 13, 1984, which is predicted to be observable throughout much of Mexico and, perhaps, in the southern United States.

  1. A game of two discs: a case of non-contiguous and occult cervical spine injury in a rugby player

    PubMed Central

    O'Sullivan, Michael D.; Piggot, Robert; Jaddan, Mutaz; McCabe, John P.

    2016-01-01

    The aim of this case report was to highlight the application of magnetic resonance imaging (MRI) in elucidating serious and occult injuries in a single case of hyperflextion injury of a patient cervical spine (C-Spine). A chart and radiology review was performed to establish the sequence of care and how the results of imaging studies influenced the clinical management in this trauma case. Plain radiographs and computed tomography (CT) imaging modalities of the C-Spine revealed bilateral C4/C5 facetal subluxation with no obvious fractures; however, the MR imaging of the C-Spine revealed a non-contiguous and occult injury to C6/C7 disc with a posterior annular tear and associated disc extrusion. This altered the operative intervention that was initially planned. MR imaging proved an invaluable diagnostic addition in this particular case of cervical trauma in a rugby player following a hyperflextion injury, by revealing a serious non-contiguous and occult injury of the C-Spine. PMID:26980714

  2. A game of two discs: a case of non-contiguous and occult cervical spine injury in a rugby player.

    PubMed

    O'Sullivan, Michael D; Piggot, Robert; Jaddan, Mutaz; McCabe, John P

    2016-01-01

    The aim of this case report was to highlight the application of magnetic resonance imaging (MRI) in elucidating serious and occult injuries in a single case of hyperflextion injury of a patient cervical spine (C-Spine). A chart and radiology review was performed to establish the sequence of care and how the results of imaging studies influenced the clinical management in this trauma case. Plain radiographs and computed tomography (CT) imaging modalities of the C-Spine revealed bilateral C4/C5 facetal subluxation with no obvious fractures; however, the MR imaging of the C-Spine revealed a non-contiguous and occult injury to C6/C7 disc with a posterior annular tear and associated disc extrusion. This altered the operative intervention that was initially planned. MR imaging proved an invaluable diagnostic addition in this particular case of cervical trauma in a rugby player following a hyperflextion injury, by revealing a serious non-contiguous and occult injury of the C-Spine. PMID:26980714

  3. Sports fractures.

    PubMed Central

    DeCoster, T. A.; Stevens, M. A.; Albright, J. P.

    1994-01-01

    Fractures occur in athletes and dramatically influence performance during competitive and recreational activities. Fractures occur in athletes as the result of repetitive stress, acute sports-related trauma and trauma outside of athletics. The literature provides general guidelines for treatment as well as a variety of statistics on the epidemiology of fractures by sport and level of participation. Athletes are healthy and motivated patients, and have high expectations regarding their level of function. These qualities make them good surgical candidates. Although closed treatment methods are appropriate for most sports fractures, an aggressive approach to more complicated fractures employing current techniques may optimize their subsequent performance. PMID:7719781

  4. Treatment Options for Metastatic Squamous Neck Cancer with Occult Primary

    MedlinePlus

    ... Patient Hypopharyngeal Cancer Treatment Laryngeal Cancer Treatment Lip & Oral Cavity Treatment Metastatic Squamous Neck Cancer with Occult Primary ... Nasal Cavity Cancer Treatment Salivary Gland Cancer Treatment Oral Cavity and Oropharyngeal Cancer Prevention Oral Cavity and Oropharyngeal ...

  5. Stages of Metastatic Squamous Neck Cancer with Occult Primary

    MedlinePlus

    ... Patient Hypopharyngeal Cancer Treatment Laryngeal Cancer Treatment Lip & Oral Cavity Treatment Metastatic Squamous Neck Cancer with Occult Primary ... Nasal Cavity Cancer Treatment Salivary Gland Cancer Treatment Oral Cavity and Oropharyngeal Cancer Prevention Oral Cavity and Oropharyngeal ...

  6. Treatment Option Overview (Metastatic Squamous Neck Cancer with Occult Primary)

    MedlinePlus

    ... Patient Hypopharyngeal Cancer Treatment Laryngeal Cancer Treatment Lip & Oral Cavity Treatment Metastatic Squamous Neck Cancer with Occult Primary ... Nasal Cavity Cancer Treatment Salivary Gland Cancer Treatment Oral Cavity and Oropharyngeal Cancer Prevention Oral Cavity and Oropharyngeal ...

  7. Nondimensional Representations for Occulter Design and Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Cady, Eric

    2011-01-01

    An occulter is a spacecraft with a precisely-shaped optical edges which ies in formation with a telescope, blocking light from a star while leaving light from nearby planets una ected. Using linear optimization, occulters can be designed for use with telescopes over a wide range of telescope aperture sizes, science bands, and starlight suppression levels. It can be shown that this optimization depends primarily on a small number of independent nondimensional parameters, which correspond to Fresnel numbers and physical scales and enter the optimization only as constraints. We show how these can be used to span the parameter space of possible optimized occulters; this data set can then be mined to determine occulter sizes for various mission scenarios and sets of engineering constraints.

  8. Analysis from Stellar Occultation and Lightcurve Observation of 582 Olympia

    NASA Astrophysics Data System (ADS)

    Matsuoka, Y.; Okamoto, R.; Sugimoto, S.; Mayu Shibata; Watanabe, D.

    2012-05-01

    Our aim is to estimate 3D shape of an asteroid. We tried to find the shape of 582 Olympia. We conducted two observations: stellar occulation and lightcurve of an asteroid. We have observed lightcurves and occultations of several asteroid.

  9. Radio occultation based on BeiDou satellite navigation

    NASA Astrophysics Data System (ADS)

    Jiang, Hu; Hu, Haiying; Shen, Xue-min; Gong, Wenbin; Zhang, Yonghe

    2014-11-01

    With the development of GNSS systems, it has become a tendency that radio occultation is used to sense the Earth's atmosphere. By this means, the moisture, temperature, pressure, and total electron content can be derived. Based on the sensing results, more complicated models for atmosphere might come into being. Meteorology well benefits from this technology. As scheduled, the BD satellite navigation system will have a worldwide coverage by the end of 2020. Radio occultation studies in China have been highlighted in the recent decade. More and more feasibilities reports have been published in either domestic or international journals. Herein, some scenarios are proposed to assess the coverage of radio occultation based on two different phases of BD satellite navigation system. Phase one for BD is composed of GEO,IGSO and several MEO satellites. Phase two for BD consists mostly of 24 MEO satellites, some GEO and IGSO satellites. The characteristics of radio occultation based on these two phases are presented respectively.

  10. A smart capsule system of gastric occult blood detection.

    PubMed

    Liu, Hongying; Qiao, Panpan; Wu, Xueli; Wang, Li; Ao, Yilu; Jia, Ziru; Pi, Xitian

    2014-01-01

    Prior research indicated that occult blood screening can be used to detect early gastric cancer. Based on capsule endoscopy and occult blood detection theory, an automatic detection capsule system for gastric occult blood (GOB) was proposed. This paper designed the detecting sensor, image acquisition system and wireless transmitter module respectively based on collaurum immune theory, the image sensor and radio frequency chip. In vitro experiments were conducted to testify the system, and the detecting result image information was acquired by the image acquisition (IMAQ) system and transmitted to the outside of the body through the wireless transmitter module. The receiver module received and displayed the information on the computer, from which doctors could diagnose whether there was occult blood (OB) or not. Therefore, this paper provides a new idea for the screening of early-stage gastric cancer with reliability and simplicity. PMID:24211935