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Sample records for distal radius endoprosthesis

  1. Limb-sparing surgery using tantalum metal endoprosthesis in a dog with osteosarcoma of the distal radius

    PubMed Central

    MacDonald, Tamara L.; Schiller, Teresa D.

    2010-01-01

    A 5-year-old, male neutered, mixed breed dog was presented for left forelimb lameness and swelling over the left distal radius. A primary bone tumor of the distal radius was diagnosed and limb-sparing surgery of the left forelimb was performed using a tantalum metal-DCP endoprosthesis. Post-operative histopathology confirmed osteosarcoma. PMID:20676291

  2. [Fracture endoprosthesis of distal humerus fractures].

    PubMed

    Müller, L P; Wegmann, K; Burkhart, K J

    2013-08-01

    The treatment of choice for fractures of the distal humerus is double plate osteosynthesis. Due to anatomical preshaped angle stable plates the primary stability and management of soft tissues has been improved. However, osteoporotic comminuted fractures in the elderly are often not amenable to stable osteosynthesis and total elbow arthroplasty has been established as an alternative therapy. Although complication rates have been reduced, complications of total elbow arthroplasty are still much more frequent than in total hip replacement. Furthermore, patients are advised not to exceed a weight bearing of 5 kg. Therefore, the indications for elbow arthroplasty must be evaluated very strictly and should be reserved for comminuted distal humeral fractures in the elderly with poor bone quality that are not amenable to stable osteosynthesis or for simple fractures in cases of preexisting symptomatic osteoarthritis. This article introduces and discusses modern concepts of elbow arthroplasty, such as modular convertible prosthesis systems, hemiarthroplasty and radial head replacement in total elbow arthroplasty.

  3. Nonbridging external fixation of distal radius fractures.

    PubMed

    Eichenbaum, Matthew D; Shin, Eon K

    2010-08-01

    Surgical management of distal radius fractures continues to evolve because of their high incidence in an increasingly active elderly population. Traditional radiocarpal external fixation relies on ligamentotaxis for fracture reduction but has several drawbacks. Nonbridging external fixation has evolved to provide early wrist mobility in the setting of anatomic fracture reduction. Several studies of the nonbridging technique have demonstrated satisfactory results in isolated nonbridging external fixation series and in comparison with traditional spanning external fixation. Nonbridging external fixation for surgical treatment of distal radius fractures can be technically demanding and requires at least 1 cm of intact volar cortex in the distal fracture fragment for successful implementation.

  4. Exposure of the forearm and distal radius.

    PubMed

    Klausmeyer, Melissa A; Mudgal, Chaitanya

    2014-11-01

    Approaches to the forearm use internervous planes to allow adequate bone exposure and prevent muscle denervation. The Henry approach utilizes the plane between muscles supplied by the median and radial nerves. The Thompson approach utilizes the plane between muscles supplied by the radial and posterior interosseous nerves. The distal radius may be approached volarly. The extended flexor carpi radialis approach is useful for intraarticular fractures, subacute fractures, and malunions. The distal radius can be approached dorsally by releasing the third dorsal compartment and continuing the dissection subperiosteally. Choice of approach depends on the injury pattern and the need for exposure. PMID:25440071

  5. Fractures of Distal Radius: An Overview

    PubMed Central

    Meena, Sanjay; Sharma, Pankaj; Sambharia, Abhishek Kumar; Dawar, Ashok

    2014-01-01

    Fractures of distal radius account for up to 20% of all fractures treated in emergency department. Initial assessment includes a history of mechanism of injury, associated injury and appropriate radiological evaluation. Treatment options include conservative management, internal fixation with pins, bridging and non-bridging external fixation, dorsal or volar plating with/without arthroscopy assistance. However, many questions regarding these fractures remain unanswered and good prospective randomized trials are needed. PMID:25657938

  6. Ultrasound-Assisted Distal Radius Fracture Reduction

    PubMed Central

    Socransky, Steve; Skinner, Andrew; Bromley, Mark; Smith, Andrew; Anawati, Alexandre; Middaugh, Jeff; Ross, Peter

    2016-01-01

    Introduction Closed reduction of distal radius fractures (CRDRF) is a commonly performed emergency department (ED) procedure. The use of point-of-care ultrasound (PoCUS) to diagnose fractures and guide reduction has previously been described. The primary objective of this study was to determine if the addition of PoCUS to CRDRF changed the perception of successful initial reduction. This was measured by the rate of further reduction attempts based on PoCUS following the initial clinical determination of achievement of best possible reduction. Methods  We performed a multicenter prospective cohort study, using a convenience sample of adult ED patients presenting with a distal radius fracture to five Canadian EDs. All study physicians underwent standardized PoCUS training for fractures. Standard clinically-guided best possible fracture reduction was initially performed. PoCUS was then used to assess the reduction adequacy. Repeat reduction was performed if deemed indicated. A post-reduction radiograph was then performed. Clinician impression of reduction adequacy was scored on a 5 point Likert scale following the initial clinically-guided reduction and following each PoCUS scan and the post-reduction radiograph. Results  There were 131 patients with 132 distal radius fractures. Twelve cases were excluded prior to analysis. There was no significant difference in the assessment of the initial reduction status by PoCUS as compared to the clinical exam (mean score: 3.8 vs. 3.9; p = 0.370; OR 0.89; 95% CI 0.46 to 1.72; p = 0.87). Significantly fewer cases fell into the uncertain category with PoCUS than with clinical assessment (2 vs 12; p = 0.008). Repeat reduction was performed in 49 patients (41.2%). Repeat reduction led to a significant improvement (p < 0.001) in the PoCUS determined adequacy of reduction (mean score: 4.3 vs 3.1; p < 0.001). In this group, the odds ratio for adequate vs. uncertain or inadequate reduction assessment using PoCUS was 12.5 (95% CI 3

  7. Ultrasound-Assisted Distal Radius Fracture Reduction.

    PubMed

    Socransky, Steve; Skinner, Andrew; Bromley, Mark; Smith, Andrew; Anawati, Alexandre; Middaugh, Jeff; Ross, Peter; Atkinson, Paul

    2016-01-01

    Introduction Closed reduction of distal radius fractures (CRDRF) is a commonly performed emergency department (ED) procedure. The use of point-of-care ultrasound (PoCUS) to diagnose fractures and guide reduction has previously been described. The primary objective of this study was to determine if the addition of PoCUS to CRDRF changed the perception of successful initial reduction. This was measured by the rate of further reduction attempts based on PoCUS following the initial clinical determination of achievement of best possible reduction. Methods  We performed a multicenter prospective cohort study, using a convenience sample of adult ED patients presenting with a distal radius fracture to five Canadian EDs. All study physicians underwent standardized PoCUS training for fractures. Standard clinically-guided best possible fracture reduction was initially performed. PoCUS was then used to assess the reduction adequacy. Repeat reduction was performed if deemed indicated. A post-reduction radiograph was then performed. Clinician impression of reduction adequacy was scored on a 5 point Likert scale following the initial clinically-guided reduction and following each PoCUS scan and the post-reduction radiograph. Results  There were 131 patients with 132 distal radius fractures. Twelve cases were excluded prior to analysis. There was no significant difference in the assessment of the initial reduction status by PoCUS as compared to the clinical exam (mean score: 3.8 vs. 3.9; p = 0.370; OR 0.89; 95% CI 0.46 to 1.72; p = 0.87). Significantly fewer cases fell into the uncertain category with PoCUS than with clinical assessment (2 vs 12; p = 0.008). Repeat reduction was performed in 49 patients (41.2%). Repeat reduction led to a significant improvement (p < 0.001) in the PoCUS determined adequacy of reduction (mean score: 4.3 vs 3.1; p < 0.001). In this group, the odds ratio for adequate vs. uncertain or inadequate reduction assessment using PoCUS was 12.5 (95% CI 3

  8. [Distal radius fractures: conservative or surgical treatment?].

    PubMed

    Mark, G; Ryf, C

    1993-07-01

    The "classical" Colles fracture of the distal radius is the most common fracture in the adult. In order to reduce the still rather high rate of permanent disability, this fracture involving a functionally important joint requires accurate reduction. The AO-fracture classification introduced by Müller not only defines the severity of an injury, but also allows for decision-making as to the most adequate treatment. Besides the purely conservative management by closed reduction and plaster cast for the type-A fractures, we have a number of other treatment modalities for the more complex-B and C-type fractures, such as closed reduction and percutaneous K-wire application or the use of the small external fixator as well as open reduction and internal fixation by plates and screws for a few selected indications. PMID:8211844

  9. Osteoarticular Allograft Reconstruction for an Angiosarcoma of the Distal Radius.

    PubMed

    Mavrogenis, Andreas F; Galanopoulos, John; Vottis, Christos; Megaloikonomos, Panayiotis D; Palmerini, Emanuela; Kokkalis, Zinon T

    2016-01-01

    Angiosarcoma of bone is a rare high-grade malignant vascular tumor accounting for <1% of malignant bone tumors. Tumor location in the distal radius is very rare. Complete surgical resection with limb salvage surgery or amputation is essential for the outcome of the patient. However, the literature is vague regarding the best surgical approach for resection of the distal radius and the optimal reconstruction option after a bone tumor resection. Several reconstruction techniques have been described, varying from arthrodesis to arthroplasties. In this article, we present a report of a patient with angiosarcoma of the distal radius treated with complete resection and reconstruction with a distal radius osteoarticular allograft. We discuss the advantages and the limitations of this surgical technique for the distal radius. PMID:27649764

  10. An Asian Perspective on the Management of Distal Radius Fractures

    PubMed Central

    Sebastin, Sandeep J.; Chung, Kevin C.

    2012-01-01

    Synopsis There is little data with regards to the epidemiology, pathology, or management of distal radius fractures from centers in Asia. Asia includes five advanced economies, namely Hong Kong SAR, Japan, Korea, Singapore, and Taiwan and a number of emerging economies prominent among which are China, India, Malaysia, Philippines, and Thailand. This article examines the available epidemiological data from Asia, and compares the management of distal radius fractures in the advanced and emerging Asian economies and how they match up to the current management in the west. It concludes by offering solutions for improving outcomes of distal radius fractures in both the advanced and emerging economies of Asia. PMID:22554658

  11. An Asian perspective on the management of distal radius fractures.

    PubMed

    Sebastin, Sandeep J; Chung, Kevin C

    2012-05-01

    There is limited data regarding the epidemiology, pathology, and management of distal radius fractures from centers in Asia. The advanced economies in Asia include Hong Kong, Japan, Korea, Singapore, and Taiwan, whereas the prominent emerging economies are China, India, Malaysia, Philippines, and Thailand. This article examines the available epidemiological data from Asia, compares the management of distal radius fractures in the advanced and emerging Asian economies and how they compare with the current management in the west. It concludes by offering solutions for improving outcomes of distal radius fractures in Asia.

  12. 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.

  13. Future treatment and research directions in distal radius fracture.

    PubMed

    Jupiter, Jesse

    2012-05-01

    Whether or not they will have their lives dramatically extended in the next few decades, it is clear that people are living longer, healthier, and more active lives. The two peak incidences of distal radius fractures will remain within the pediatric and geriatric age groups, with the latter experiencing a substantial increase in the coming years. This article attempts to project future developments with regard to epidemiology, risk and prevention, fracture assessment, and treatment of distal radius fractures, and the ever increasing concern for the economic impact of this prevalent injury.

  14. Ultrasound-Guided Reduction of Distal Radius Fractures

    PubMed Central

    Sabzghabaei, Anita; Shojaee, Majid; Arhami Dolatabadi, Ali; Manouchehrifar, Mohammad; Asadi, Mahdi

    2016-01-01

    Introduction: Distal radius fractures are a common traumatic injury, particularly in the elderly population. In the present study we examined the effectiveness of ultrasound guidance in the reduction of distal radius fractures in adult patients presenting to emergency department (ED). Methods: In this prospective case control study, eligible patients were adults older than 18 years who presented to the ED with distal radius fractures. 130 consecutive patient consisted of two group of Sixty-Five patients were prospectively enrolled for around 1 years. The first group underwent ultrasound-guided reduction and the second (control group) underwent blind reduction. All procedures were performed by two trained emergency residents under supervision of senior emergency physicians. Results: Baseline characteristics between two groups were similar. The rate of repeat reduction was reduced in the ultrasound group (9.2% vs 24.6%; P = .019). The post reduction radiographic indices were similar between the two groups, although the ultrasound group had improved volar tilt (mean, 7.6° vs 3.7°; P = .000). The operative rate was reduced in the ultrasound groups (10.8% vs 27.7%; P = .014). Conclusion: Ultrasound guidance is effective and recommended for routine use in the reduction of distal radius fractures. PMID:27299141

  15. Reverse wedge osteotomy of the distal radius in Madelung's deformity.

    PubMed

    Mallard, F; Jeudy, J; Rabarin, F; Raimbeau, G; Fouque, P-A; Cesari, B; Bizot, P; Saint-Cast, Y

    2013-06-01

    Madelung's deformity results from a growth defect in the palmar and ulnar region of the distal radius. It presents as an excessively inclined radial joint surface, inducing "spontaneous progressive palmar subluxation of the wrist". The principle of reverse wedge osteotomy (RWO) consists in the reorientation of the radial joint surface by taking a circumferential bone wedge, the base of which is harvested from the excess of the radial and dorsal cortical bone of the distal radius, then turning it over and putting back this reverse wedge into the osteotomy so as to obtain closure on the excess and opening on the deficient cortical bone. RWO corrects the palmar subluxation of the carpus and improves distal radio-ulnar alignment. All five bilaterally operated patients were satisfied, esthetically and functionally. Its corrective power gives RWO a place apart among the surgical techniques currently available in Madelung's deformity.

  16. [Results following percutaneous intramedullary pin fixation in distal radius fractures].

    PubMed

    Kirchner, R; Hüttl, T; Krüger-Franke, M; Rosemeyer, B

    1994-01-01

    42 distal radius fractures have been submitted to further examination after percutaneous intramedullary pin fixation. The outcome were 95.3% of very good to good anatomic results and 90.5% of satisfying functional results. This showed the close link between the radiological-anatomical and functional results. The success of the treatment was very acceptable, although the Morbus Sudeck as the major complication--with 7.2%--was still relatively frequently observed. It could be seen that particularly fractures at the risk of dislocation with smash zone constituted an indication for the percutaneous intramedullary pin fixation, that is to say all fractures for which a retention is primarily difficult. It constitutes a supplement, as well as an extension to the therapy of the distal radius fractures. PMID:7516105

  17. Distal Radius Isoelastic Resurfacing Prosthesis: A Preliminary Report

    PubMed Central

    Ichihara, Satoshi; Díaz, Juan José Hidalgo; Peterson, Brett; Facca, Sybille; Bodin, Frédéric; Liverneaux, Philippe

    2015-01-01

    Background Here we present a preliminary case series of unicompartmental isoelastic resurfacing prosthesis of the distal radius to treat comminuted articular fractures of osteoporotic elderly patients. Materials and Methods Our study included 12 patients, mean age 76 years, who presented with comminuted osteoporotic distal radius fracture. Because of the severity of injury and poor bone quality; osteosynthesis was not deemed to be a good option. Description of Technique The surgery was performed through a dorsal approach. The subchondral bone of the entire distal radial articular was excised and a unicompartmental prosthesis was applied. Results At an average follow-up of 32 months, the pain was 2.8/10, Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) 37.4/100, grip strength in neutral 49.9%, in supination 59.0%, and in pronation 56.2% of the contralateral normal side. The wrist ranges of motion in flexion and extension were 56.1% and 79.3%, in supination and pronation 87.7% and 91.0% of the contralateral normal side. Two patients experienced a complex regional pain syndrome (CRPS) type II; these resolved spontaneously. One patient experienced distal radioulnar joint (DRUJ) stiffness, which improved after an ulna head resection. Finally, one patient required revision surgery after a secondary traumatic fracture. Radiographically; the average volar tilt was 9.8°; the average of radial inclination was 11.6°. Conclusion The concept of a unicompartmental isoelastic resurfacing prosthesis offers a promising option for the treatment of comminuted, osteoporotic distal radius articular fractures of elderly patients. Level of Evidence IV PMID:26261738

  18. Medical management of fragility fractures of the distal radius.

    PubMed

    Morgan, Emily N; Crawford, David A; Scully, William F; Noce, Nicholas J

    2014-12-01

    Fragility fractures of the distal radius represent an opportunity to diagnose and treat osteoporosis before further fractures occur. The goal of this study was to determine the prevalence of prescriptions for calcium/vitamin D supplementation and the prevalence of dual-energy x-ray absorptiometry (DEXA) scans in patients who sustained fragility fractures of the distal radius. A further goal was to determine the prevalence of patients who received prescriptions for the treatment of osteoporosis after DEXA scans. The authors performed a retrospective review of all patients 50 years and older who sustained a fragility fracture of the distal radius and were treated by the orthopedic surgery service at the authors' institution from 2004 to 2010. After a fragility fracture of the distal radius, fewer than 25% of previously unidentified at-risk patients received a prescription for vitamin supplementation and underwent a DEXA scan. Women were 7 times more likely than men to receive calcium/vitamin D supplementation, 14 times more likely to undergo a DEXA scan for the evaluation of osteoporosis, and 25 times more likely to receive a prescription for bisphosphonates. Patients who underwent a DEXA scan were 9 times more likely to receive pharmacologic treatment than those who did not undergo this scan. More than half of patients did not receive a prescription for calcium/vitamin D supplementation and did not undergo DEXA scanning as recommended by current National Osteoporosis Foundation guidelines. Most patients who received prescriptions or underwent DEXA scans did so before rather than after fracture, indicating poor compliance with National Osteoporosis Foundation guidelines. PMID:25437080

  19. Epithelioid Hemangioendothelioma of the Distal Radius: A Case Report.

    PubMed

    Duncan, Scott F M; Krochmal, Daniel J; Craft, Randall O; Merritt, Marianne V; Smith, Anthony A

    2007-01-01

    Epithelioid hemangioendothelioma is a rare vascular tumor with cytologic behavior between angiosarcoma and hemangioma. We present the case of a 58-year-old male with primary epithelioid hemangioendothelioma of the distal radius measuring 6.2 × 5 cm with extension into the pronator quadratus and brachioradialis muscles. We discuss our approach to performing a limb-sparing resection combined with reconstruction to preserve upper extremity function. A review of the clinical, radiographic, and pathologic features of epithelioid hemangioendothelioma is also presented.

  20. Medical management of fragility fractures of the distal radius.

    PubMed

    Morgan, Emily N; Crawford, David A; Scully, William F; Noce, Nicholas J

    2014-12-01

    Fragility fractures of the distal radius represent an opportunity to diagnose and treat osteoporosis before further fractures occur. The goal of this study was to determine the prevalence of prescriptions for calcium/vitamin D supplementation and the prevalence of dual-energy x-ray absorptiometry (DEXA) scans in patients who sustained fragility fractures of the distal radius. A further goal was to determine the prevalence of patients who received prescriptions for the treatment of osteoporosis after DEXA scans. The authors performed a retrospective review of all patients 50 years and older who sustained a fragility fracture of the distal radius and were treated by the orthopedic surgery service at the authors' institution from 2004 to 2010. After a fragility fracture of the distal radius, fewer than 25% of previously unidentified at-risk patients received a prescription for vitamin supplementation and underwent a DEXA scan. Women were 7 times more likely than men to receive calcium/vitamin D supplementation, 14 times more likely to undergo a DEXA scan for the evaluation of osteoporosis, and 25 times more likely to receive a prescription for bisphosphonates. Patients who underwent a DEXA scan were 9 times more likely to receive pharmacologic treatment than those who did not undergo this scan. More than half of patients did not receive a prescription for calcium/vitamin D supplementation and did not undergo DEXA scanning as recommended by current National Osteoporosis Foundation guidelines. Most patients who received prescriptions or underwent DEXA scans did so before rather than after fracture, indicating poor compliance with National Osteoporosis Foundation guidelines.

  1. Complications of pediatric distal radius and forearm fractures.

    PubMed

    Chia, Benjamin; Kozin, Scott H; Herman, Martin J; Safier, Shannon; Abzug, Joshua M

    2015-01-01

    Distal radius and forearm fractures represent a large percentage of pediatric fractures. The most common mechanism of injury is a fall onto an outstretched arm, which can lead to substantial rotational displacement. If this rotational displacement is not adequately addressed, there will be resultant loss of forearm motion and subsequent limitations in performing the activities of daily living. Good initial reductions and proper casting techniques are necessary when treating distal radius and forearm fractures nonsurgically; however, maintaining an acceptable reduction is not always possible. Atraumatic reduction of a displaced physeal fracture should occur within 7 days of the injury. If an impending malunion presents at 2 weeks or later after injury, observation is warranted because of concerns about physeal arrest with repeated attempts at manipulation, and it should be followed by a later assessment of functional limitations. Pediatric patients and their parents have higher expectations for recovery, which has contributed to an increase in the surgical management of pediatric distal radius and forearm fractures. In addition, surgical interventions, such as intramedullary nailing, have their own associated complications.

  2. Distal humerus fractures in the elderly: osteosynthesis or endoprosthesis? Review of the literature.

    PubMed

    Dietz, S O; Burkhart, K E; Nowak, T E; Rommens, P M; Müller, L P

    2012-12-01

    Fractures of the distal humerus in adults are rare but challenging for the orthopaedic trauma surgeon. The bimodal distribution reflects the trauma mechanism. While distal humerus fractures are caused by high-energy traumata in young male adults, a fall from a standing height is the most common reason for humerus fractures among elderly females. As a rule, fractures of the distal humerus are treated surgically. In young patients, open reduction and internal fixation (ORIF) with anatomic locking plates are the gold standard. In elderly patients, reconstruction is not always possible, and total elbow arthroplasty (TEA) becomes necessary. The present article provides an overview of the current diagnostic and treatment recommendations. The current literature is reviewed and the results discussed. PMID:26814545

  3. [Differential treatment of fractures of the distal radius].

    PubMed

    Oestern, H J; Hüls, E

    1994-01-01

    Treatment of distal fractures of the radius has undergone considerable change during recent years. The cause for this lies primarily in the poor results of conservative treatments. In addition to osseous instability, the fractures of the radius are frequently combined with ligamentary instability as well, thereby exceeding the ability of conservative treatment. Among the many classifications, the AO classification of these fractures has proven to be the best and most widely accepted. This classification allows the recommendation of suitable procedures of treatment. The problem with inadequately healed fractures of the radius lies in the inherent unphysiological loading of the joint in the characteristic dorsal tilted position. This leads to a pathological displacement of the radius of flexion and extension and thereby to an overloading of the dorsal joint cartilage. The shortening of the radius leads to a mechanical impingement of the triangular fibrocartilagenous complex. The Kirschner wire fixation is particularly indicated in type A and type C fractures when combined with an external fixator. Of great importance here is the crossing of the K-wires, best accomplished by inserting an additional wire in a proximal to distal direction to achieve maximal mechanical stability. Biodegradable fixation devices are not yet in widespread use, as high costs and possible foreign body reactions have prevented their acceptance. The plate osteosynthesis has its domain in the treatment of volar luxation fractures (B3) and the partially articular fractures of the radius (B2). The domain of the external fixator, on the other hand, lies in the C2 and C3 fractures in combination with the K-wire osteosynthesis. Changing the mode of treatment to a plate osteosynthesis after two to three weeks allows a functional postoperative treatment. By use of a differentiated treatment regimen, the complication rate can be significantly reduced whose cause frequently lies in repeatedly attempted

  4. Distal Radius Attachments of the Radiocarpal Ligaments: An Anatomical Study

    PubMed Central

    Zumstein, M. A.; Hasan, A. P.; McGuire, D. T.; Eng, Kevin; Bain, Gregory Ian

    2013-01-01

    Background Understanding the anatomy of the ligaments of the distal radius aids in the surgical repair of ligamentous injuries and the prediction of intraarticular fracture patterns. Purposes (1) to measure the horizontal and vertical distances of the origins of the radiocarpal ligaments from the most ulnar corner of the sigmoid notch and the joint line, respectively; and (2) to express them as a percentile of the total width of the bony distal radius. Methods We dissected 8 cadaveric specimens and identified the dorsal radiocarpal, radioscaphocapitate, and the long and short radiolunate ligaments. Results The dorsal radiocarpal ligament attached from the 16th to the 52nd percentile of the radial width. The radioscaphocapitate ligament attached around the radial styloid from the 86th percentile volarly to the 87th percentile dorsally. The long radiolunate ligament attached from the 59th to the 85th percentile, and the short radiolunate ligament attached from the 14th to the 41st percentile. Discussion There was a positive correlation between the radial width and the horizontal distance of the ligaments from the sigmoid notch. These findings may aid individualized surgical repair or reconstruction adjusted to patient size and enable further standardized research on distal radial fractures and their relationship with radiocarpal ligaments. PMID:24436840

  5. Stabilisation of distal radius fractures: Lessons learned and future directions.

    PubMed

    Horst, Taylor A; Jupiter, Jesse B

    2016-02-01

    Our understanding of the diagnosis and management of distal radius fractures has been a long developed over centuries. There has been a shift in treatment of these very common injuries from closed reduction and casting to internal fixation. The answer to the best method of treatment has yet to be found. Today, we have a multitude of treatment options available with varying degrees of evidence to support their use. This review helps to illustrate the lessons we have learned and future directions for treatment.

  6. Measurement of ulnar variance and radial inclination on X-rays of healed distal radius fractures. With the axis of the distal radius or ulna?

    PubMed

    Thuysbaert, Gilles; Ringburg, Akkie; Petronilia, Steven; Vanden Berghe, Alex; Hollevoet, Nadine

    2015-06-01

    Ulnar variance and radial inclination are radiological parameters frequently used to evaluate displacement of distal radius fractures. In most studies measurements are based on the long central axis of the distal radius, although the axis of the distal ulna can also be used. The purpose of this study was to determine which axis is more reliable. Four observers performed measurements on standard anteroposterior digital wrist X-rays of 20 patients taken 1 and 2 months after sustaining an extra-articular distal radius fracture. Intraobserver reliability was similar with both methods. No difference was found in interobserver reliability between both methods for ulnar variance, but for radial inclination it was better with the axis through the radius. Measurements on two X-rays of the same wrist taken at a different moment were similar with both methods. It can be concluded that the central axis of the distal radius can remain the basis to determine ulnar variance and radial inclination.

  7. Conservative Treatment Is Sufficient for Acute Distal Radioulnar Joint Instability With Distal Radius Fracture.

    PubMed

    Lee, Sang Ki; Kim, Kap Jung; Cha, Yong Han; Choy, Won Sik

    2016-09-01

    Treatments for acute distal radioulnar joint (DRUJ) instability with distal radius fracture vary from conservative to operative treatment, although it seems to be no consensus regarding which treatment is optimal. This prospective randomized study was designed to compare the clinical outcomes for operative and conservative treatment of acute DRUJ instability with distal radius fracture, according to the presence or absence and type of ulnar styloid process fracture and the degree of its displacement. Between July 2008 and February 2013, we enrolled 157 patients who exhibited an unstable DRUJ during intraoperative manual stress testing (via the ballottement test) after fixation of the distal radius. Patients were classified according to the type of the ulnar styloid process fracture, using preoperative wrist radiography, and each group was divided into subgroups, according to their treatment method. We then compared the clinical outcomes between the conservative and operative treatments, using their range of motion; Disabilities of the Arm, Shoulder, and Hand score; modified Mayo wrist score; and grip strength. At 3 months after surgery, among patients without ulnar styloid process fracture, the flexion-extension range was 79 ± 15° after supination sugar-tong splinting (group A-1), 91 ± 14° after DRUJ transfixation (group A-2), and 89 ± 10° after arthroscopic triangular fibrocartilage complex repair (group A-3); the operative treatments provided greater joint motion ranges than conservative treatment. The groups with ulnar styloid process fractures at the tip (group B) or base (group C) also exhibited better clinical outcomes after the operative treatments, compared with after the conservative treatment. However, at the final follow-up, groups A-1, A-2, and A-3 exhibited similar flexion-extension ranges (122 ± 25°, 119° ± 18°, and 120° ± 16°, respectively) and modified Mayo wrist scores (87 ± 7, 89 ± 8, and 85 ± 9). Thus, the conservative and

  8. Brodie's abscess of the distal radius: an unusual complication after percutaneous pinning.

    PubMed

    Johnson, Jeff W; Bindra, Randip R

    2008-12-01

    We report a case of Brodie's abscess of the distal radius that presented 4 years after closed reduction and percutaneous pinning for a closed distal radius fracture. This condition has not been previously reported in the adult distal radius and we detail the clinical features and imaging findings. We also present a new way of management of Brodie's abscess using injectable bone substitute along with adjunctive parenteral antibiotic therapy.

  9. Brodie’s Abscess of the Distal Radius: An Unusual Complication after Percutaneous Pinning

    PubMed Central

    Bindra, Randip R.

    2008-01-01

    We report a case of Brodie’s abscess of the distal radius that presented 4 years after closed reduction and percutaneous pinning for a closed distal radius fracture. This condition has not been previously reported in the adult distal radius and we detail the clinical features and imaging findings. We also present a new way of management of Brodie’s abscess using injectable bone substitute along with adjunctive parenteral antibiotic therapy. PMID:18780011

  10. Synchronous Multicentric Giant Cell Tumour of Distal Radius and Sacrum with Pulmonary Metastases

    PubMed Central

    Tandra, Varun Sharma; Kotha, Krishna Mohan Reddy; Satyanarayana, Moorthy Gadisetti Venkata; Vadlamani, Kali Varaprasad; Yerravalli, Vyjayanthi

    2015-01-01

    Giant cell tumour (GCT) is an uncommon primary bone tumour, and its multicentric presentation is exceedingly rare. We report a case of a 45-year-old female who presented to us with GCT of left distal radius. On the skeletal survey, osteolytic lesion was noted in her right sacral ala. Biopsy confirmed both lesions as GCT. Pulmonary metastasis was also present. Resection-reconstruction arthroplasty for distal radius and thorough curettage and bone grafting of the sacral lesion were done. Multicentric GCT involving distal radius and sacrum with primary sacral involvement is not reported so far to our knowledge. PMID:26106496

  11. Synchronous Multicentric Giant Cell Tumour of Distal Radius and Sacrum with Pulmonary Metastases.

    PubMed

    Tandra, Varun Sharma; Kotha, Krishna Mohan Reddy; Satyanarayana, Moorthy Gadisetti Venkata; Vadlamani, Kali Varaprasad; Yerravalli, Vyjayanthi

    2015-01-01

    Giant cell tumour (GCT) is an uncommon primary bone tumour, and its multicentric presentation is exceedingly rare. We report a case of a 45-year-old female who presented to us with GCT of left distal radius. On the skeletal survey, osteolytic lesion was noted in her right sacral ala. Biopsy confirmed both lesions as GCT. Pulmonary metastasis was also present. Resection-reconstruction arthroplasty for distal radius and thorough curettage and bone grafting of the sacral lesion were done. Multicentric GCT involving distal radius and sacrum with primary sacral involvement is not reported so far to our knowledge. PMID:26106496

  12. The Evolution of Distal Radius Fracture Management – A Historical Treatise

    PubMed Central

    Diaz-Garcia, Rafael J.; Chung, Kevin C.

    2012-01-01

    Distal radius fractures have been a common affliction for millennia, but their treatment is a more recent development as a result of human erudition. While immobilization has served as the only available treatment for most of our history, many advances have been made in the management of distal radius fractures over the last century as the field of orthopedics has grown. Yet, the topic remains hotly contested in the literature, and research continues to focus upon it given the frequency of the injury. In this article, we chronicle the evolution of distal radius fracture treatment in hopes of providing context for the future that lies ahead. PMID:22554653

  13. Concurrent Minimally Invasive Carpal Tunnel Release Techniques in Distal Radius Open Reduction Internal Fixation.

    PubMed

    Low, O-Wern; Cheah, Andre E J

    2016-02-01

    Carpal tunnel syndrome is a common complication associated with distal radius fractures. Open carpal tunnel release in the same setting as open reduction and internal fixation of distal radius fractures is widely accepted. In this paper, we describe the technical details of a minimally invasive carpal tunnel release in the same setting as the fixation of a distal radius fracture via the same incision. Two options of minimally invasive techniques are described: The Knifelight® (Stryker, Kalamazoo, Michigan, USA) instrument and the single portal carpal tunnel release system (Agee, 3M Healthcare, St Paul, Minnesota, USA). Being well known and accepted techniques of carpal tunnel release, we believe that the techniques described in this paper provide a viable alternative for carpal tunnel release in the setting of distal radius fracture fixation; with the added advantages of the original minimally invasive techniques. PMID:27454517

  14. Carpal tunnel syndrome: A rare manifestation of distal radius osteoid osteoma.

    PubMed

    Basran, Sukhvinder Singh; Kumar, Sandeep; Jameel, Javed; Sajid, Imran

    2015-09-01

    Osteoid Osteoma is a benign bone tumor that normally affects long bones and rarely affects distal radius. Because of its nonspecific presentation in the wrist, it remains a diagnostic challenge. We report an unusual case of Osteoid Osteoma at distal radius having symptoms resembling that of carpal tunnel syndrome. The diagnosis was confirmed preoperatively with X-rays; bone scintigraphy, CT, and MRI, later histological examination confirmed the diagnoses. Surgical excision lead to a dramatic improvement in the condition of the patient.

  15. Rupture of Flexor Pollicis Longus Tendon: A Complication of Volar Locking Plating of the Distal Radius.

    PubMed

    Rajeev, Aysha Sethunathan; Sreverthana, Shanaka; Harrison, John

    2010-08-01

    We report an unusual case of complete rupture of the flexor pollicis longus tendon following volar locking plating for a distal radius fracture. We believe that the prominence of a distal locking screw head predisposed to the rupture of the tendon. We highlight that correctly attaching the distal locking screws to the plate is essential for obtaining the correct biomechanics of the device and preventing flexor tendon rupture.

  16. Outcome Analysis of Fernandez Osteotomy in Malunited Extra-Articular Fractures of Distal Radius.

    PubMed

    Bhattacharyya, A; Kumar, S

    2016-07-01

    Deformity of wrist is very common after mal union of extra articular fractures over distal end of Radius. It causes limitation of movements too in different directions with or without pain. Deformity may be treated by different types of corrective osteotomy. We treated cases of this type of malunion with Fernandez osteotomy. This study is to observe the amount of correction and recovery of functional status in patients with malunited distal radius fractures treated with Fernandez osteotomy. This is a prospective study. We treated 10 cases of malunited radius with Fernandez osteotomy from February 2013 to October 2014 in the Departments of Orthopaedics, Medical College and Hospital, Kolkata, India. There were six males and four females with mean age of thirty years (with range from twenty to forty years. Indications for surgical intervention include pain and functional deficit severe enough to interfere significantly with daily activities. Radius is exposed through distal dorsal radial incision and radial osteotomy done two and half centimetre proximal to the wrist joint and after achieving correction; gap is filled with iliac bone graft and fixed with contoured distal radius T-plate. Follow up was for an average one year and three months. Results were excellent in one, satisfactory in four cases, good in four cases and bad in one case. Fernandez osteotomy is valuable option for correction of malunited distal radius fracture especially in young demanding patients. PMID:27612904

  17. Pearls and Pitfalls of the Volar Locking Plating for Distal Radius Fractures.

    PubMed

    Im, Jin-Hyung; Lee, Joo-Yup

    2016-06-01

    Volar locking plate fixation has been widely accepted method for the treatment of unstable distal radius fractures. Although the results of volar locking plate fixation are encouraging, it may cause implant-related complications such as flexor or extensor tendon injuries. In depth understanding of anatomy of the distal radius is mandatory in order to obtain adequate fixation of the fracture fragments and to avoid these complications. This article will review the anatomic characteristics of the distal radius because selecting proper implant and positioning of the plate is closely related to the volar surface anatomy of the distal radius. The number and the length of distal locking screws are also important to provide adequate fixation strength to maintain fracture fixation. We will discuss the pros and cons of the variable-angle locking plate, which was introduced in an effort to provide surgeons with more freedom for fixation. Finally, we will discuss about correcting radial length and volar tilt by using eccentric drill holes and distal locking first technique.

  18. Prebending of a titanium elastic intramedullary nail in the treatment of distal radius fractures in children.

    PubMed

    Cai, Haoqi; Wang, Zhigang; Cai, Haiqing

    2014-01-01

    The aims of this study were to introduce a method to treat distal radius diaphyseal metaphyseal junction fractures by prebending an elastic intramedullary nail and to evaluate the factors influencing fracture apposition. Fifty-two consecutive patients (4 to 15 years old) with a distal radius diaphyseal metaphyseal junction fracture were included. The nail was inserted and advanced into the proximal radial fragment as normal. After bending the nail distally about 90° at the site predetermined to lie at the distal segment, the elastic intramedullary nail was advanced until the prebent part completely entered the marrow cavity. The fracture angular deformity was fully corrected in anterior-posterior and lateral views. The apposition rate was 90% to 100% in lateral view, >50% in anterior-posterior view. The operation time was 16.73 ± 6.253 minutes. The average time of fracture healing was 5 months (range, 4-7 months). During 12 to 19 months of follow-up, firm fracture healing and good remodeling were observed, and there was no impaired forearm rotation function or secondary fracture. Our study showed the treatment of distal radius diaphyseal metaphyseal junction fractures by prebent intramedullary nail could make up for the deficiency of Kirschner wires and steel plates and keep the fracture stable. Fracture type and the anatomical features of the distal radius were associated with fracture apposition. PMID:24833151

  19. Pearls and Pitfalls of the Volar Locking Plating for Distal Radius Fractures.

    PubMed

    Im, Jin-Hyung; Lee, Joo-Yup

    2016-06-01

    Volar locking plate fixation has been widely accepted method for the treatment of unstable distal radius fractures. Although the results of volar locking plate fixation are encouraging, it may cause implant-related complications such as flexor or extensor tendon injuries. In depth understanding of anatomy of the distal radius is mandatory in order to obtain adequate fixation of the fracture fragments and to avoid these complications. This article will review the anatomic characteristics of the distal radius because selecting proper implant and positioning of the plate is closely related to the volar surface anatomy of the distal radius. The number and the length of distal locking screws are also important to provide adequate fixation strength to maintain fracture fixation. We will discuss the pros and cons of the variable-angle locking plate, which was introduced in an effort to provide surgeons with more freedom for fixation. Finally, we will discuss about correcting radial length and volar tilt by using eccentric drill holes and distal locking first technique. PMID:27454625

  20. En bloc joystick reduction of a comminuted intra-articular distal radius fracture: a technical trick.

    PubMed

    Siegall, Evan; Ziran, Bruce

    2014-08-01

    A patient with a 1-month-old intra-articular distal radius fracture (treated closed in a splint) presented with an unacceptable degree of pain and stiffness caused by shortening and dorsal angulation of the distal radius. The fracture was comminuted with 4 or 5 distinct fragments, several involving the articular surface. Surgical correction was attempted. During the procedure, it was noted that, though the distal radius was shortened and angulated, there was actually acceptable congruity of the articular surface itself, despite the intra-articular nature of the fracture. Bone quality was poor and healing incomplete. Thus, we were concerned the currently congruous articular surface would fall apart with manipulation. Given this situation, we used a unique scaffolding technique with Kirschner wires placed in perpendicular fashion to both hold the articular surface intact and manipulate it en bloc. This technique is a simple way to turn a complex fracture into an easily reduced 2-part fracture.

  1. Reconstruction of Attritional Rupture of Flexor Tendons with Fascia Lata Graft Following Distal Radius Fracture Malunion.

    PubMed

    Bhat, A K; Acharya, A M; Soni, N

    2016-10-01

    Incidence of multiple flexor tendon rupture following distal radius fractures is rare with very few cases being reported in literature. We present an unusual case of a patient who had come to us with complaints of weakness and paresthesia of the right hand of one month prior and with a past history of dorsal plating for distal radius fracture nine years ago. Radiographs showed a distal radius fracture malunion with intact dorsal plate and protrusion of screws through the volar cortex. On exploration, attritional ruptures of all digital flexors were found with sparing of the Flexor Pollicis Longus tendon. The fibrous mass was excised and flexors reconstructed with a fascia lata graft. Attempt was made to correct the malunion with radial and ulnar osteotomies. At one year the patient had excellent restoration of digital flexion. PMID:27595963

  2. Acute Ulnar Shortening for Delayed Presentation of Distal Radius Growth Arrest in an Adolescent

    PubMed Central

    Ellanti, Prasad; Harrington, Paul

    2012-01-01

    Distal radius physeal fractures are common in children and adolescents. However, posttraumatic growth arrest is uncommon. The management of posttraumatic growth arrest is dependent on the severity of the deformity and the remaining growth potential of the patient. Various treatment options exist. We present a 17-year-old male with distal radius growth arrest who presented four years after the initial injury. He had a symptomatic 15 mm positive ulnar variance managed with an ulnar shortening osteotomy with the use of the AO mini distractor intraoperatively. To the best of our knowledge, an acute ulnar shortening of 15 mm is the largest reported. PMID:23227397

  3. OSTEOTOMY OF THE DISTAL RADIUS USING A FIXED-ANGLE VOLAR PLATE

    PubMed Central

    de Oliveira, Ricardo Kaempf; Binz, Mário Arthur Rockenbach; Ferreira, Marco Tonding; Ruschel, Paulo Henrique; Serrano, Pedro Delgado; Praetzel, Rafael Pêgas

    2015-01-01

    Objective: Skewed consolidation of the distal radius, due to sequelae of fractures, may cause functional incapacity, thus leading such patients to present pain, loss of strength and diminished mobility. Based on the excellent results obtained from surgical treatment of unstable fractures of the distal radius through a volar approach and use of rigid fixation with a fixed-angle volar plate, we started to use the same method for osteotomy of the distal radius. Methods: A retrospective review was conducted, and 20 patients treated between February 2002 and October 2009 were found. The mean length of follow-up was 43.9 months (range: 12 to 96 months). The surgical indications were persistent pain, deformity and functional limitation subsequent to a dorsally displaced fracture. Results: The mean preoperative deformity was 27° of dorsal tilt of the distal radius, 87° of ulnar tilt, and 7.3 mm of shortening of the radius. All the osteotomies consolidated and the final mean volar tilt was 6.2°, with ulnar tilt of 69.3° and shortening of 1 mm. The mean mobility of the wrist increased by 19.9° (flexion) and by 24° (extension). Mean forearm supination increased by 23.5° and pronation by 21.7°. Grip strength increased from 13.4 to 34.5 pounds. Conclusion: Use of a fixed-angle volar plate for a volar approach towards osteotomy of the distal radius enables satisfactory correction of the deformities and eliminates the need for removal of the synthesis material caused by tendon complications PMID:27042618

  4. Epidemiology and changed surgical treatment methods for fractures of the distal radius

    PubMed Central

    2013-01-01

    Background and purpose The incidence of fractures of the distal radius may have changed over the last decade, and operative treatment has been commoner during that time. We investigated the incidence of fractures of the distal radius and changing trends in surgical treatment during the period 2004–2010. Patients and methods Registry data on 42,583 patients with a fracture of the distal radius from 2004 to 2010 were evaluated regarding diagnosis, age, sex, and surgical treatment. Results The crude incidence rate was 31 per 104 person-years with a bimodal distribution. After the age of 45 years, the incidence rate in women increased rapidly and leveled off first at a very high age. The incidence rate in postmenopausal women was lower than previously reported. In men, the incidence was low and it increased slowly until the age of 80 years, when it amounted to 31 per 104 person-years. The number of surgical procedures increased by more than 40% despite the fact that there was reduced incidence during the study period. In patients ≥ 18 years of age, the proportion of fractures treated with plating increased from 16% to 70% while the use of external fixation decreased by about the same amount. Interpretation The incidence rate of distal radius fractures in postmenopausal women appears to have decreased over the last few decades. There has been a shift in surgical treatment from external fixation to open reduction and plating. PMID:23594225

  5. Dorsal displacement of the ulnar nerve after a displaced distal radius fracture: case report.

    PubMed

    Sohal, Jennifer Kaur R; Chia, Benjamin; Catalano, Louis W

    2009-03-01

    We report on a patient in whom ulnar nerve palsy developed after a closed distal radius fracture due to displacement of the ulnar nerve dorsal to the ulnar styloid. After delayed exploration and decompression of the ulnar nerve, the patient had recovery of both motor and sensory function of the ulnar nerve.

  6. Sagittal wrist motion of carpal bones following intraarticular fractures of the distal radius.

    PubMed

    Lutz, M; Rudisch, A; Kralinger, F; Smekal, V; Goebel, G; Gabl, M; Pechlaner, S

    2005-06-01

    Forty patients (mean age, 37 years) with intraarticular C2 and C3 Colles fractures were treated by open reduction, internal fixation and bone grafting. At a mean follow-up of 8 years radiocarpal and midcarpal motion was evaluated, the depth of the articular surface of the distal radius in the sagittal plane was measured and the presence of arthritis was noted. The fractures healed with a mean palmar tilt of 6 degrees , a mean ulnar tilt of 18 degrees and ulna variance within 1 mm of the contralateral side. The depth of the articular surface of the distal radius was 1.3 mm greater than the uninvolved side. Measurement of carpal bone angles relative to the radius in maximum flexion and extension revealed lunate extension of 23 degrees , lunate flexion of 15 degrees , capitate extension of 62 degrees , capitate flexion of 40 degrees . There was a significant correlation between articular surface depth and radiocarpal motion.

  7. Type IIA Monteggia Fracture Dislocation with Ipsilateral Distal Radius Fracture in Adult – A Rare Association

    PubMed Central

    James, Boblee

    2016-01-01

    Monteggia fracture constitutes about 5-10% of the forearm fractures. Monteggia fracture by definition is proximal ulnar fracture with disruption of proximal radioulnar joint. Bado classified Monteggia fracture dislocation into four types and Jupiter subclassified type II Bado’s fractures into four types. The associated injury in the form of distal radial fractures and distal humerus fractures are rare though many cases of distal radial physeal injuries have been reported in paediatric population. Hereby we report a rare association of type IIA Monteggia fracture dislocation with ipsilateral distal radius fracture in an adult patient. This case report also highlights on proper examination and full length radiographs of forearm to avoid missing injury at wrist in cases of elbow injuries. Management of such complex injuries included open reduction and internal fixation of olecronon fracture, distal radius fracture and radial head resection. Functional outcome at six months was good at wrist whereas at elbow, stiffness was a major concern with elbow range of movement from 40°-110°. PMID:27656518

  8. Type IIA Monteggia Fracture Dislocation with Ipsilateral Distal Radius Fracture in Adult - A Rare Association.

    PubMed

    Kembhavi, Raghavendra S; James, Boblee

    2016-08-01

    Monteggia fracture constitutes about 5-10% of the forearm fractures. Monteggia fracture by definition is proximal ulnar fracture with disruption of proximal radioulnar joint. Bado classified Monteggia fracture dislocation into four types and Jupiter subclassified type II Bado's fractures into four types. The associated injury in the form of distal radial fractures and distal humerus fractures are rare though many cases of distal radial physeal injuries have been reported in paediatric population. Hereby we report a rare association of type IIA Monteggia fracture dislocation with ipsilateral distal radius fracture in an adult patient. This case report also highlights on proper examination and full length radiographs of forearm to avoid missing injury at wrist in cases of elbow injuries. Management of such complex injuries included open reduction and internal fixation of olecronon fracture, distal radius fracture and radial head resection. Functional outcome at six months was good at wrist whereas at elbow, stiffness was a major concern with elbow range of movement from 40°-110°. PMID:27656518

  9. [Intra-articular fracture of the distal radius: results following osteosynthesis with a support plate].

    PubMed

    Ferguson, G A; Leutenegger, A; Mark, G; Breiter, H; Rüedi, T

    1989-01-01

    The treatment of comminuted intra-articular fractures of the distal radius often requires an operative fixation. Beside the recently recommended external fixator, the support plate fixation offers a helpful alternative to treatment. Between 1980 and 1986, 30 wrists in 29 patients with intra-articular fractures of the distal radius were stabilized with a buttress plate an the Kantonsspital Chur, Switzerland. The mean follow-up-time was 15 months. These follow-ups showed that the buttress plate in treatment of complicated intra-articular fractures allows a satisfactory reduction and stabilization with restoration of the articular congruity and the possibility for early active assisted motion. Buttress plate fixation still remains a demanding technique, which in complicated cases, should be reserved for the experienced surgeon. PMID:2500786

  10. Brodie's abscess following percutaneous fixation of distal radius fracture in a child.

    PubMed

    Rajakulendran, Karthig; Picardo, Natasha E; El-Daly, Ibraheim; Hussein, Rami

    2016-04-01

    We report the case of a Brodie's abscess presenting five and a half years following closed reduction and percutaneous pinning of a distal radius fracture. The index surgery was complicated by a pin site infection that was treated successfully with antibiotics. The patient represented with forearm pain years later, and radiological investigations revealed a Brodie's abscess in the distal radius at the site of the previous Kirschner wires. The Brodie's abscess was managed through surgical curettage and antibiotics. Staphylococcus aureus and diphtheroid organisms were cultured from the intraoperative specimens. A Brodie's abscess is a form of localised subacute osteomyelitis, which usually occurs in the metaphysis of long bones and can mimic malignancy. Previous trauma or surgery has been implicated as predisposing factors. We have only identified one previously reported case of Brodie's abscess following percutaneous pinning. Ours is the first reported case in an adolescent. The aim of this paper is to raise awareness of this rare complication and review the current literature.

  11. Measurement of Malrotation on Direct Radiography in Pediatric Distal Radius Fractures

    PubMed Central

    Duymus, Tahir Mutlu; Mutlu, Serhat; Komur, Baran; Mutlu, Harun; Yucel, Bulent; Parmaksizoglu, Atilla Sancar

    2016-01-01

    Abstract The aim of this prospective study was to test a mathematical method of measuring the malrotation of pediatric distal radius fractures (PDRFs) from direct radiographs. A total of 70 pediatric patients who presented at the Emergency Department with a distal radius fracture were evaluated. For 38 selected patients conservative treatment for PDRF was planned. Anteroposterior and lateral radiographs were taken of all of the patients for comparison before and after reduction. Radius bone diameters were measured in the coronal and sagittal planes on the healthy and fractured sides. Using the diameter values on the healthy side and the new diameter values on the fractured side in the rotation formula, the degree of malrotation between the fracture ends was calculated. The mean follow-up period was 13.5 months. Patients’ mean age was 10.00 ± 3.19 years (range, 4–12 years). The rotation degree in the sagittal plane significantly differed between the proximal (26.52°±2.84°) and distal fracture ends (20.96°±2.73°) (P = 0.001). The rotation degree in the coronal plane significantly differed between the proximal (26.70°±2.38°) and distal fracture ends (20.26°±2.86°) (P = 0.001). The net rotation deformity of the fracture line was determined to be 5.55°± 3.54° on lateral radiographs and 5.44°± 3.35° on anteroposterior radiographs, no significant difference was observed between measurements (P >0.05). The malrotation deformity in PDRF occurs with greater rotation in the proximal fragment than in the distal fragment. The net rotation deformity created between the fracture ends can be calculated on direct radiographs. Level of Evidence: Diagnostic, Level II PMID:27149480

  12. Is Bone Grafting Necessary in the Treatment of Malunited Distal Radius Fractures?

    PubMed Central

    Disseldorp, Dominique J. G.; Poeze, Martijn; Hannemann, Pascal F. W.; Brink, Peter R. G.

    2015-01-01

    Background Open wedge osteotomy with bone grafting and plate fixation is the standard procedure for the correction of malunited distal radius fractures. Bone grafts are used to increase structural stability and to enhance new bone formation. However, bone grafts are also associated with donor site morbidity, delayed union at bone–graft interfaces, size mismatch between graft and osteotomy defect, and additional operation time. Purpose The goal of this study was to assess bone healing and secondary fracture displacement in the treatment of malunited distal radius fractures without the use of bone grafting. Methods Between January 1993 and December 2013, 132 corrective osteotomies and plate fixations without bone grafting were performed for malunited distal radius fractures. The minimum follow-up time was 12 months. Primary study outcomes were time to complete bone healing and secondary fracture displacement. Preoperative and postoperative radiographs during follow-up were compared with each other, as well as with radiographs of the uninjured side. Results All 132 osteotomies healed. In two cases (1.5%), healing took more than 4 months, but reinterventions were not necessary. No cases of secondary fracture displacement or hardware failure were observed. Significant improvements in all radiographic parameters were shown after corrective osteotomy and plate fixation. Conclusion This study shows that bone grafts are not required for bone healing and prevention of secondary fracture displacement after corrective osteotomy and plate fixation of malunited distal radius fractures. Level of evidence Therapeutic, level IV, case series with no comparison group PMID:26261748

  13. The Impact of Patient Activity Level on Wrist Disability after Distal Radius Malunion in Older Adults

    PubMed Central

    Nelson, Gregory N.; Stepan, Jeffrey G.; Osei, Daniel A.; Calfee, Ryan P.

    2014-01-01

    Objective To determine if high-activity older adults are adversely affected by distal radius malunion. Design Cross-sectional study. Setting Hand clinics at a tertiary institution. Participants 96 patients ≥60 years old at time of fracture evaluated at least 1 year following distal radius fracture. Intervention Physical Activity Scale of the Elderly (PASE) scores stratified participants into high- and low-activity groups. Malunions were defined radiographically by change of ≥20° of lateral tilt, ≥15° radial inclination, ≥4 mm of ulnar variance, or ≥4 mm intra-articular gap or step-off, compared to the uninjured wrist. Main Outcome Measure Patient-rated disability of the upper-extremity was measured by the QuickDASH and Visual Analog Scales (VAS) for pain/function. Strength and motion measurements objectively quantified wrist function. Results High-activity participants with a distal radius malunion were compared to high-activity participants with well-aligned fractures. There was no significant difference in QuickDASH scores, VAS function, strength, and wrist motion despite statistically, but not clinically relevant, increases in VAS pain scores (difference 0.5, p=0.04) between the groups. Neither PASE score (β= 0.001, 95%CI: −0.002 to 0.004) nor malunion (β=0.133, 95%CI: −0.26 to 0.52) predicted QuickDASH scores in regression modeling after accounting for age, sex, and treatment. Operative management failed to improve outcomes and resulted in decreased grip strength (p=0.05) and more frequent complications (26% vs 7%, p=0.01) when compared to nonoperatively management. Conclusion Even among highly active older adults, distal radius malunion does not impact functional outcomes. Judicious use of operative management is warranted provided heightened complication rates. PMID:25233158

  14. [New minimally invasive approach for palmar plating in distal radius fractures].

    PubMed

    Chmielnicki, M; Prokop, A

    2015-02-01

    Distal radius fractures are among the most common fractures. Types A3 and C2 make up almost half of these. Volar fixed-angle plate fixation is the gold standard of treatment today. We wanted to minimise the approach to the distal radius through a transverse 2-3 cm incision in the wrist flexor fold, tunnelling beneath the pronator muscle. The operative technique is demonstrated here. 11 patients, averaging 70 years of age, underwent surgery for 7 A3 and 4 C2 type fractures. Average operating time was 50 minutes. Length of admission averaged 2.9 days. Using a visual analogue scale, pain decreased from 6/10 preoperatively to 3/10 on post-op day one and 2/10 on post-op day three. After 6 weeks, flexion and extension averaged 45-0-45°, and radial and ulnar deviation 20-0-20°. Pronation and supination averaged 85-0-85°. Grip strength with manometer averaged 90 % compared to the contralateral side at 6 weeks and 96 % at 3 months. As comparison, from 1 January 2008 until 31 May 2013, we treated 908 patients with distal radius fractures with volar fixed-angle plates through a conventional longitudinal incision of 5-8 cm. The average skin to skin time was 46 minutes, with an average length of admission of 5.6 days. A minimally invasive approach to treat distal radius fractures with volar plate fixation and sparing of the pronator muscle is possible. The initial patients treated with this approach experienced minimal post-operative pain, shorter hospital admissions, and rapid grip strength recovery with almost undisturbed rotational motion.

  15. Inter- and intra-observer agreement of the AO classification for operatively treated distal radius fractures.

    PubMed

    van Buijtenen, Jesse M; van Tunen, Mischa L C; Zuidema, Wietse P; Heilbron, Emile A; de Haan, Jeroen; de Vet, Henrica C W; Derksen, Robert J

    2015-11-01

    The reproducibility of the AO classification for distal radius fractures remains a topic of debate. Previous studies showed variable reproducibility results. Important treatment decisions depend on correct classification, especially in comminuted, intra-articular fractures. Therefore, reliable reproducibility results need to be undisputedly determined. Hence, the study objective was to assess inter- and intra-observer agreement of the AO classification for operatively treated distal radius fractures. A database of 54 radiographs of all AO types (A, B and C) and groups (A2-3, B1-3, and C1-3) of distal radius fractures was assessed in twofold. Likewise, a subset of 152 radiographs of solely C-type groups (C1-3) was assessed. All fractures were classified by six observers with different experience levels: three consultant trauma surgeons, one sixth-year trauma surgery resident, a consultant trauma radiologist, and an intern with limited experienced. The inter-observer agreement of both main types and groups was moderate (κ = 0.49 resp. κ = 0.48) in combination with a good intra-observer agreement (κ = 0.68 resp. κ = 0.70). The inter-observer agreement of the subset C-type fractures group was fair (κ = 0.27) with moderate intra-observer agreement (κ = 0.43). According to these results, the reproducibility of the AO classification of main types and groups of distal radius fractures based on conventional radiographs is insufficient (κ < 0.50), especially at group level of C-type fractures. PMID:26614083

  16. Salter-Harris type-IV displaced distal radius fracture in a 5-year-old.

    PubMed

    Huntley, Samuel R; Summers, Spencer H; Stricker, Stephen J

    2016-03-01

    Displaced Salter-Harris type-IV fractures are rare in young children and can result in articular incongruity or premature physeal arrest. We describe a 5-year-old boy who sustained a displaced left distal radial Salter-Harris type-IV fracture. The patient had normal wrist function and physeal growth at the 3-year postoperative follow-up. Our patient is by far the youngest reported child with a displaced Salter-Harris type-IV fracture of the distal radius. Prompt anatomic reduction and fixation of a displaced distal radial Salter-Harris type-IV fracture can result in excellent short-term wrist motion with maintenance of physeal function.

  17. Treatment of Distal Radius Fracture Nonunion With Posterior Interosseous Bone Flap

    PubMed Central

    Saremi, Hossein; Shahryar-Kamrani, Reza; Ghane, Bahareh; Yavarikia, Alireza

    2016-01-01

    Background Nonunion of distal radius fractures is disabling. Treatment is difficult and the results are not predictable. However, posterior interosseous bone flap (PIBF) has been successful in treating forearm nonunion. Objectives To treat distal radius fracture nonunion with PIBF as a new procedure. Patients and Methods This prospective non-randomized cohort study was performed at two hospitals in Tehran between January 2011 and September 2015. PIBFs were applied in nine patients (10 nonunions) with a mean age of 55 years. Union success rate, grip strength, wrist range of motion, and forearm rotation were then evaluated. Results Although four of the patients had a history of infection, all participants achieved fracture union at a mean time of 3.8 months. Grip strength improved by 12.4 kg. There was also 36° improvement in wrist flexion, 20° improvement in wrist extension, 60° improvement in forearm supination, and 46° improvement in forearm pronation. The range of motion and grip strength improvements were significant. Conclusions Pedicled PIBF is a new option for treating distal radius fracture nonunion. The results are predictable in achieving union and good function, and this technique can be successfully used in cases with extensive soft-tissue damage or infection.

  18. Bone geometry, density, and strength indices of the distal radius reflect loading via childhood gymnastic activity.

    PubMed

    Dowthwaite, Jodi N; Flowers, Portia P E; Spadaro, Joseph A; Scerpella, Tamara A

    2007-01-01

    The distal radius bears unique forces during gymnastic activity. Its relatively simple anatomy, minimal soft tissue envelope, and varied composition make the distal radius ideal for evaluating the effects of loading on bone properties. For 56 premenarcheal gymnasts and nongymnasts, ultradistal and 1/3 distal radius DXA scans measured bone mineral content (BMC), areal bone mineral density, and projected area. Simplified geometric models were used to generate bone mineral apparent density (BMAD), geometric indices, strength indices, and fall strength ratios. Ratios of regional BMC vs total body fat-free mass (FFM) were calculated. Separate Tanner I and II analyses of covariance adjusted bone parameters for age and height. Ratios were compared using maturity-matched analyses of variance. At the 1/3 region, periosteal width, BMC, cortical cross-sectional area, and section modulus were greater in gymnasts than nongymnasts (p<0.05); 1/3 BMAD means were equivalent. Ultradistal BMAD, BMC, and index for structural strength in axial compression were higher in gymnasts than nongymnasts; ultradistal periosteal width was only larger in Tanner I gymnasts. Fall strength ratios and BMC/FFM ratios were greater in gymnasts (p<0.05). Geometric and volumetric responses to mechanical loading are site specific during late childhood and early adolescence.

  19. The Utility of the Fluoroscopic Skyline View During Volar Locking Plate Fixation of Distal Radius Fractures

    PubMed Central

    Vaiss, Lucile; Ichihara, Satoshi; Hendriks, Sarah; Taleb, Chihab; Liverneaux, Philippe; Facca, Sybille

    2014-01-01

    Background Open reduction and internal fixation (ORIF) using a volar locking plate is a common method for treating displaced distal radius fractures. There is, however, the risk of extensor tendon rupture due to protrusion of the screw tips past the dorsal cortex, which cannot always be adequately seen on a lateral fluoroscopic view. We therefore wished to compare the sensitivity of an intraoperative fluoroscopic skyline view to a lateral fluorosocopic view in detecting past pointing of these screws. Material and Methods Our series included 75 patients with an average age of 59 years who underwent volar locked plate fixation of a displaced distal radius fracture. Intraoperative anteroposterior (AP), lateral, and skyline fluoroscopic views were performed in each case. The number of screws that were seen to protrude past the dorsal cortex of the distal fracture fragment were recorded for both the lateral and skyline views. The number of screws that required exchange was also documented. Results No screws were seen to protrude past the dorsal cortical bone on the lateral fluroscopic views. 15 of 300 screws (5%) were seen to protrude past the dorsal cortex by an average of 0.8 mm (range, 0.5 to 2 mm) and were exchanged for shorter screws in 11/75 patients. Conclusion Our results demonstrate that the skyline is more sensitive than a lateral fluoroscopic view at demonstrating protrusion of the screws in the distal fracture fragment following volar locked plate fixation. Level of Evidence IV PMID:25364637

  20. ULTRASOUND SIMULATION IN THE DISTAL RADIUS USING CLINICAL HIGH-RESOLUTION PERIPHERAL-CT IMAGES

    PubMed Central

    Floch, Vincent Le; McMahon, Donald J.; Luo, Gangming; Cohen, Adi; Kaufman, Jonathan J.; Shane, Elizabeth; Siffert, Robert S.

    2008-01-01

    The overall objective of this research is to develop an ultrasonic method for noninvasive assessment of the distal radius. The specific objective of this study was to examine the propagation of ultrasound through the distal radius and determine the relationships between bone mass and architecture and ultrasound parameters. Twenty-six high-resolution peripheral-CT clinical images were obtained from a set of subjects that were part of a larger study on secondary osteoporosis. A single midsection binary slice from each image was selected and used in the two-dimensional (2D) simulation of an ultrasound wave propagating from the anterior to the posterior surfaces of each radius. Mass and architectural parameters associated with each radius, including total (trabecular and cortical) bone mass, trabecular volume fraction, trabecular number and trabecular thickness were computed. Ultrasound parameters, including net time delay (NTD), broadband ultrasound attenuation (BUA) and ultrasound velocity (UV) were also evaluated. Significant correlations were found between NTD and total bone mass (R2 = 0.92, p < 0.001), BUA and trabecular number (R2 = 0.78, p < 0.01) and UV and trabecular bone volume fraction (R2 = 0.82, p < 0.01). There was only weak, statistically insignificant correlation (R2 < 0.14, p = 0.21) found between trabecular thickness and any of the ultrasound parameters. The study shows that ultrasound measurements are correlated with bone mass and architecture at the distal radius and, thus, ultrasound may prove useful as a method for noninvasive assessment of osteoporosis and fracture risk. PMID:18343017

  1. Bone Geometry, Density and Strength Indices of the Distal Radius Reflect Loading via Childhood Gymnastic Activity

    PubMed Central

    Dowthwaite, Jodi N.; Flowers, Portia P.E.; Spadaro, Joseph A.; Scerpella, Tamara A.

    2007-01-01

    The distal radius bears unique forces during gymnastic activity. Its relatively simple anatomy, minimal soft tissue envelope and varied composition make the distal radius ideal for evaluating the effects of loading on bone properties. For 56 premenarcheal gymnasts and non-gymnasts, ultradistal and 1/3 distal radius DXA scans measured bone mineral content (BMC), areal bone mineral density and projected area. Simplified geometric models were used to generate bone mineral apparent density (BMAD), geometric indices, strength indices and fall strength ratios. Ratios of regional BMC vs. total body fat free mass (FFM) were calculated. Separate Tanner I and II analyses of covariance adjusted bone parameters for age and height. Ratios were compared using maturity-matched analyses of variance. At the 1/3 region, periosteal width, BMC, cortical cross-sectional area, and section modulus were greater in gymnasts than non-gymnasts (p<0.05); 1/3 BMAD means were equivalent. Ultradistal BMAD, BMC and index for structural strength in axial compression were higher in gymnasts than non-gymnasts; ultradistal periosteal width was only larger in Tanner I gymnasts. Fall strength ratios and BMC/FFM ratios were greater in gymnasts (p<0.05). Geometric and volumetric responses to mechanical loading are site-specific during late childhood and early adolescence. The distal radius bears unique forces during gymnastic activity, and fan beam magnification error is negligible at this site, making it ideal for DXA evaluation of associated bone properties. For 56 premenarcheal gymnasts and non-gymnasts, ultradistal and 1/3 distal radius DXA scans measured bone mineral content, areal bone mineral density and projected area. Simplified geometric models were used to generate bone mineral apparent density, geometric indices, strength indices and fall strength ratios. Ratios of regional bone mineral content vs. total body fat free mass were calculated. Separate Tanner I and II analyses of covariance

  2. Automated Classification of Epiphyses in the Distal Radius and Ulna using a Support Vector Machine.

    PubMed

    Wang, Ya-hui; Liu, Tai-ang; Wei, Hua; Wan, Lei; Ying, Chong-liang; Zhu, Guang-you

    2016-03-01

    The aim of this study was to automatically classify epiphyses in the distal radius and ulna using a support vector machine (SVM) and to examine the accuracy of the epiphyseal growth grades generated by the support vector machine. X-ray images of distal radii and ulnae were collected from 140 Chinese teenagers aged between 11.0 and 19.0 years. Epiphyseal growth of the two elements was classified into five grades. Features of each element were extracted using a histogram of oriented gradient (HOG), and models were established using support vector classification (SVC). The prediction results and the validity of the models were evaluated with a cross-validation test and independent test for accuracy (PA ). Our findings suggest that this new technique for epiphyseal classification was successful and that an automated technique using an SVM is reliable and feasible, with a relative high accuracy for the models. PMID:27404614

  3. Acute plastic bowing of the radius with a distal radioulnar joint injury: a case report.

    PubMed

    Uehara, Masashi; Yamazaki, Hiroshi; Kato, Hiroyuki

    2010-01-01

    Acute plastic bowing is an incomplete fracture with a deformation that shows no obvious macroscopic fracture line or cortical discontinuity. Although cases of acute plastic bowing of the ulna with a dislocation of the radial head have been previously reported, we present here a rare case of acute plastic bowing of the radius with a distal radioulnar joint injury in a 16-year-old boy. Internal fixation of the detached fragment to the ulnar styloid and repair of the triangular fibrocartilagenous complex resulted in the disappearance of wrist pain. In cases of distal radioulnar joint injuries in children or adolescents, radiographs of the entire forearm should be taken to evaluate the existence of radial bowing. PMID:21089197

  4. Distal Radius Volar Rim Fracture Fixation Using DePuy-Synthes Volar Rim Plate.

    PubMed

    Kachooei, Amir Reza; Tarabochia, Matthew; Jupiter, Jesse B

    2016-03-01

    Background To assess the results of distal radius fractures with the involvement of the volar rim fixed with the DePuy-Synthes Volar Rim Plate. Case Description We searched for the patients with volar rim fracture and/or volar rim fractures as part of a complex fracture fixed with a volar rim plate. Ten patients met the inclusion criteria: three patients with type 23B3, six patients with type 23C, and one patient with very distal type 23A. The mean follow-up was 14 months (range: 2-26). Fractures healed in all patients. Of the three patients with isolated volar rim fractures (type 23B3), two patients had no detectable deficits in motion. These patients had an average Gartland and Werley score of 9 (range: 2-14). Of the other seven patients (six with type 23C and one with type 23A fracture), three patients healed with full range of motion and four had some deficits in range of motion. Two patients had excellent results, three had good results, and two had fair results using the Gartland and Werley categorical rating. One patient healed with a shortened radius and ulnar impingement requiring a second surgery for ulnar head resection arthroplasty. Literature Review Results after nonoperative treatment of volar rim fractures are not satisfactory and often require subsequent corrective osteotomy. Satisfactory outcomes are achieved when the fragments are well reduced and secured regardless of the device type. Clinical Relevance Volar rim plates give an adequate buttress of the volar radius distal to volar projection of the lunate facet and do not interfere with wrist mobility. Furthermore, the dorsal fragments can be fixed securely through the volar approach eliminating the need for a secondary posterior incision. However, patients should be informed of the potential problems and the need to remove the plate if symptoms develop.

  5. Distal radius geometry and skeletal strength indices after peripubertal artistic gymnastics

    PubMed Central

    Scerpella, T. A.

    2011-01-01

    Summary Development of optimal skeletal strength should decrease adult bone fragility. Nongymnasts (NON) were compared with girls exposed to gymnastics during growth (EX/GYM), using peripheral quantitative computed tomography (pQCT) to evaluate postmenarcheal bone geometry, density, and strength. Pre- and perimenarcheal gymnastic loading yields advantages in indices of postmenarcheal bone geometry and skeletal strength. Introduction Two prior studies using pQCT have reported bone density and size advantages in Tanner I/II gymnasts, but none describe gymnasts’ bone properties later in adolescence. The current study used pQCT to evaluate whether girls exposed to gymnastics during late childhood growth and perimenarcheal growth exhibited greater indices of distal radius geometry, density, and skeletal strength. Methods Postmenarcheal subjects underwent 4% and 33% distal radius pQCT scans, yielding: 1) vBMD and cross-sectional areas (CSA) (total bone, compartments); 2) polar strength-strain index; 3) index of structural strength in axial compression. Output was compared for EX/GYM vs. NON, adjusting for gynecological age and stature (maturity and body size), reporting means, standard errors, and significance. Results Sixteen postmenarcheal EX/GYM (age 16.7 years; gynecological age 3.4 years) and 13 NON (age 16.2 years; gynecological age 3.6 years) were evaluated. At both diaphysis and metaphysis, EX/GYM exhibited greater CSA and bone strength indices than NON; EX/GYM exhibited 79% larger intramedullary CSA than NON (p<0.05). EX/GYM had significantly higher 4% trabecular vBMD; differences were not detected for 4% total vBMD and 33% cortical vBMD. Conclusions Following pre-/perimenarcheal gymnastic exposure, relative to nongymnasts, postmenarcheal EX/GYM demonstrated greater indices of distal radius geometry and skeletal strength (metaphysis and diaphysis) with greater metaphyseal trabecular vBMD; larger intramedullary cavity size was particularly striking. PMID

  6. [Efficacy of compound Xiatianwu tablets in elderly patients with osteoporotic distal radius fractures].

    PubMed

    Zhang, Bin; Chen, Gang; Li, Hai-long; Ren, Hai-peng; Yang, Tao; Chen, Min; Guo, Li-gang

    2015-06-01

    Xiatianwu tablet is based on the theory of traditional Chinese medicine (TCM), combined with modern TCM pharmacology and selected 33 famous traditional Chinese crude drugs to compose. Its recipe helps cure rheumatism, relax tendons, promote blood circulation to relieve pain, et al. Although Xiatianwu tablets are widely applied to clinical remedy such as rheumatic arthritis, lumbar disc hernia, osteoarthritis and so on, there is no report about its application in fracture. This article is to observe the efficacy of compound Xiatianwu tablets in elderly patients with osteoporotic distal radius fractures and its impact on the wrist function and complications. 180 elderly patients with osteoporotic distal radius fractures, from January 2011 to June 2014, were divided into observation group and control group by the method of random number table, each group had 90 cases. The control group were gave Caltrate D after manipulative reduction and plaster immobilization, observation group were treated with compound Xiatianwu tablets in the basis of the control group. Efficacy, wrist function and complication rates were observed in two groups after treatment. The excellent and good rate was 95.56% in observation group better than 77.78% in control group, the difference was statistically significant (χ2 = 4.712, P < 0.05). The complication rate in observation group was significantly lower compared with the control group (P < 0.05). This study shows that compound Xiatianwu tablets can improve the efficacy in elderly patients with osteoporotic distal radius fractures, reduce the incidence of complications and relieve the pain of patients which plays a significant role in improving the quality of life. PMID:26591540

  7. MRI of bone marrow in the distal radius: in vivo precision of effective transverse relaxation times

    NASA Technical Reports Server (NTRS)

    Grampp, S.; Majumdar, S.; Jergas, M.; Lang, P.; Gies, A.; Genant, H. K.

    1995-01-01

    The effective transverse relaxation time T2* is influenced by the presence of trabecular bone, and can potentially provide a measure of bone density as well as bone structure. We determined the in vivo precision of T2* in repeated bone marrow measurements. The T2* measurements of the bone marrow of the distal radius were performed twice within 2 weeks in six healthy young volunteers using a modified water-presaturated 3D Gradient-Recalled Acquisition at Steady State (GRASS) sequence with TE 7, 10, 12, 20, and 30; TR 67; flip angle (FA) 90 degrees. An axial volume covering a length of 5.6 cm in the distal radius was measured. Regions of interest (ROIs) were determined manually and consisted of the entire trabecular bone cross-section extending proximally from the radial subchondral endplate. Reproducibility of T2* and area measurements was expressed as the absolute precision error (standard deviation [SD] in ms or mm2) or as the relative precision error (SD/mean x 100, or coefficient of variation [CV] in %) between the two-point measurements. Short-term precision of T2* and area measurements varied depending on section thickness and location of the ROI in the distal radius. Absolute precision errors for T2* times were between 1.3 and 2.9 ms (relative precision errors 3.8-9.5 %) and for area measurements between 20 and 55 mm2 (relative precision errors 5.1-16.4%). This MR technique for quantitative assessment of trabecular bone density showed reasonable reproducibility in vivo and is a promising future tool for the assessment of osteoporosis.

  8. Vascularized proximal fibular autograft for treatment of post-traumatic segmental bony defects in the distal radius.

    PubMed

    Shimizu, Takamasa; Yajima, Hiroshi; Kobata, Yasunori; Shigematsu, Koji; Kawamura, Kenji; Takakura, Yoshinori

    2008-11-01

    Vascularized proximal fibular autograft is reported as one of the reconstructive procedures for the wrists following tumor resection in the distal end of the radius. However, it is rarely performed for the treatment of segmental bony defects in the distal radius after trauma. A 19-year-old man who had traumatic bony defects in the distal radius involving the articular surface underwent vascularized proximal fibular grafting for reconstruction of the wrist. After surgery, he regained wrist functions, with 40 degrees of flexion, 45 degrees of extension, 90 degrees of pronation, and 45 degrees of supination. No evidence of instability or degenerative changes was noted in the reconstructed wrist at 3 years after surgery. Vascularized proximal fibular autograft appears a useful procedure both for reconstruction of the wrist in cases with segmental bony defects in the distal radius after trauma, as well as for after tumor resection. PMID:18925543

  9. 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

  10. Can carpal malalignment predict early and late instability in nonoperatively managed distal radius fractures?

    PubMed

    Batra, Sameer; Debnath, U; Kanvinde, R

    2008-10-01

    The purpose of this study was to assess the frequency of carpal instability as a concomitant lesion in distal radius fractures and identify other factors including carpal malalignment in an attempt to predict the final radiological outcome more accurately following conservative treatment of distal radius fractures. An observational study from patient records and standardised radiological follow-up examinations as data sources was used. The alignment of each wrist was checked radiographically immediately post-reduction and subsequently at 1- and 6-week follow-up assessments. Serial measurements of radial length, dorsal tilt, radial inclination, scapho-lunate, radio-lunate, radioscaphoid, scapho-capitate angles and effective radiolunate flexion angle were made. Regression analysis showed high correlation among the severity of axial shortening, pre-reduction dorsal angulation and radio-carpal malalignment pattern with early loss of reduction at 1 week. We found the age, severity of axial radial shortening, dorsal angulation, presence of dorsal comminution and radio-carpal malalignment pattern to be significant predictors of adverse radiological outcome at 6 weeks (late instability). Our study highlights the importance of radio-carpal instability pattern on post-reduction radiographs as a predictor of early and late instability.

  11. Primary Wrist Hemiarthroplasty for Irreparable Distal Radius Fracture in the Independent Elderly

    PubMed Central

    Herzberg, Guillaume; Burnier, Marion; Marc, Antoine; Izem, Yadar

    2015-01-01

    Background Volar plating for acute distal radius fractures (DRF) in the elderly has been recommended. Some studies have suggested that open reduction with internal fixation (ORIF) in this situation results in frequent complications. Our purposes were to provide a definition of irreparable DRF in independent elderly patients and to review the results of a preliminary retrospective series of wrist hemiarthroplasty (WHA) in this patient population. Materials Between 2011 and 2014, 11 consecutive independent elderly patients (12 wrists) with irreparable intra-articular DRF were treated with primary WHA at the acute stage. A resection of the ulnar head was associated in nine wrists. A total of 11 wrists with more than 2 years of follow-up form the basis of this paper. Description of Technique The approach was dorsal longitudinal. An osteotome longitudinally entered the dorsal aspect of the fracture medial to the Lister tubercle. Two thick osteoperiosteal flaps were elevated radially and ulnarly in a fashion similar to opening a book. The distal radius articular surface was excised. The implant was pressed into the radial canal with attention to restoring distal radius length. The two osteoperiosteal flaps were brought back together and sutured so as to close, again like a book, the osseous and soft tissues around the implant. Results At mean follow-up of 30 months, average visual analog scale (VAS) pain was 1/10. Mean QuickDASH (Disabilities of the Arm, Shoulder and Hand) score was 32, and mean Patient-Rated Wrist Evaluation (PRWE) score was 24. Mean forearm rotation arc was 151°. Mean active flexion-extension arc was 60°. Mean active extension was 34°. Mean grip strength was 14 kg (64% of contralateral wrist). Mean Lyon wrist score was 73%. Bone healing around the implants was satisfactory in all but one case. Conclusions Out data suggest that treatment of irreparable DRF in the independent elderly patient with a bone-preserving WHA may be a viable

  12. Assessment of the healing process in distal radius fractures by high resolution peripheral quantitative computed tomography.

    PubMed

    de Jong, Joost J A; Willems, Paul C; Arts, Jacobus J; Bours, Sandrine G P; Brink, Peter R G; van Geel, Tineke A C M; Poeze, Martijn; Geusens, Piet P; van Rietbergen, Bert; van den Bergh, Joop P W

    2014-07-01

    In clinical practice, fracture healing is evaluated by clinical judgment in combination with conventional radiography. Due to limited resolution, radiographs don't provide detailed information regarding the bone micro-architecture and bone strength. Recently, assessment of in vivo bone density, architectural and mechanical properties at the microscale became possible using high resolution peripheral quantitative computed tomography (HR-pQCT) in combination with micro finite element analysis (μFEA). So far, such techniques have been used mainly to study intact bone. The aim of this study was to explore whether these techniques can also be used to assess changes in bone density, micro-architecture and bone stiffness during fracture healing. Therefore, the fracture region in eighteen women, aged 50 years or older with a stable distal radius fracture, was scanned using HR-pQCT at 1-2 (baseline), 3-4, 6-8 and 12weeks post-fracture. At 1-2 and 12 weeks post-fracture the distal radius at the contra-lateral side was also scanned as control. Standard bone density, micro-architectural and geometric parameters were calculated and bone stiffness in compression, torsion and bending was assessed using μFEA. A linear mixed effect model with time post-fracture as fixed effect was used to detect significant (p-value ≤0.05) changes from baseline. Wrist pain and function were scored using the patient-rated wrist evaluation (PRWE) questionnaire. Correlations between the bone parameters and the PRWE score were calculated by Spearman's correlation coefficient. At the fracture site, total and trabecular bone density increased by 11% and 20%, respectively, at 6-8 weeks, whereas cortical density was decreased by 4%. Trabecular thickness increased by 23-31% at 6-8 and 12 weeks and the intertrabecular area became blurred, indicating intertrabecular bone formation. Compared to baseline, calculated bone stiffness in compression, torsion and bending was increased by 31% after 12 weeks. A

  13. [Technique and results of modified percutaneous bore wire osteosynthesis of the distal radius].

    PubMed

    Habernek, H; Schmid, L

    1992-07-01

    A modified technique for percutaneous K-wire pinning of distal radius fractures is presented. With this method, three to four K-wires are introduced from the radial styloid process towards and through the dorsal, volar and ulnar proximal cortical wall, respectively. After the fracture fragments have been demonstrated to be stable, the wires are cut, bent over and fixed. Then a dorsal plaster splint is applied, which should be worn for 4-6 weeks, depending on whether or not there is a dorsal comminution zone. Fifty-five patients have been operated on by this method. At follow-up 6 months after the operation, no secondary dislocation, wire migration, infection, Sudeck syndrome or functional disturbance was seen. The advantage of this method is emphasized as compared with the usual, previously published method. PMID:1502573

  14. Intraoperative C-arm CT imaging in angular stable plate osteosynthesis of distal radius fractures.

    PubMed

    Mehling, I; Rittstieg, P; Mehling, A P; Küchle, R; Müller, L P; Rommens, P M

    2013-09-01

    The purpose of this study was to analyze the practicability and benefit of intraoperative C-arm computed tomography (CT) imaging in volar plate osteosynthesis of unstable distal radius fractures. During a 1 year period, intraoperative three dimensional (3D) imaging with the ARCADIS Orbic 3D was performed in addition to standard fluoroscopy in 51 cases. The volar angular stable plate oesteosyntheses were analyzed intraoperatively and, if necessary, improved immediately. The duration of the scan and radiation exposure dose were measured. On average, performance of the scan and analysis of the CT dataset took 6.7 minutes. In 31.3% of the surgeries a misplacement of screws was detected and correction was done immediately. C-arm CT imaging can easily be integrated in the normal course of surgery. As a complement to the standard 2D-fluoroscopy, the C-arm CT is a useful tool to evaluate the quality of osteosynthesis.

  15. Retrospective comparison of percutaneous fixation and volar internal fixation of distal radius fractures.

    PubMed

    Lozano-Calderón, Santiago A; Doornberg, Job N; Ring, David

    2008-06-01

    A change in the practice of a single surgeon provided an opportunity for retrospective comparison of comparable cohorts treated with percutaneous fixation (17 patients) or a volar plate and screws (23 patients) an average of 30 months after surgery. The final evaluation was performed according to the Gartland and Werley and Mayo rating systems and the DASH questionnaire. There were no significant differences on the average scores for the percutaneous and volar plating groups, respectively: Gartland and Werley, 4 vs 5; Mayo, 82 vs 83; and DASH score 13 for both cohorts. Motion, grip, and radiographical parameters were likewise comparable. Volar internal plate and screw fixation can achieve results comparable to percutaneous fixation techniques in the treatment of fractures of the distal radius.

  16. Distal radius fractures-Design of locking mechanism in plate system and recent surgical procedures.

    PubMed

    Inagaki, Katsunori; Kawasaki, Keikichi

    2016-05-01

    Recently, many studies have emphasized the importance of the comprehension of detailed functional anatomy of the distal forearm and wrist joint, and their biomechanics. A significant contribution which yields good functional outcomes of surgical treatment was the development of the locking plate technology; this technology has facilitated the improvement of the surgical technique for the fixation of fractures. This article reviews the locking mechanism and design of the fixation screws and plate, and the details of the surgical technique including the double-tired subchondral support procedure as it is applied to common fractures. Arthroscopic-assisted surgical procedures can be used to reduce the intra-articular fracture fragments after realignment of the distal radius with the locking plate. This technique is also useful at the time of fixation to assess soft tissue injury. The combination of arthroscopic-assisted reduction and locking plate fixation is now indicated for AO type C2 and C3 intra-articular comminuted fractures. PMID:27006135

  17. A Brachioradialis Splitting Approach Sparing the Pronator Quadratus for Volar Plating of the Distal Radius.

    PubMed

    Kashir, Abdalla; O'Donnell, Turlough

    2015-12-01

    Fractures of the distal radius account for up to 15% of all extremity fractures. Volar plating has become more popular, as it allows locking plate technology to be applied. Traditionally, access to the volar radius has been achieved through the approach of Henry using the interval between flexor carpi radialis and the radial artery, involving incising the radial border of the pronator quadratus (PQ). With this approach, PQ repair is difficult, and when attempted is often incomplete or tenuous, as it is a direct muscle-to-muscle repair. Theoretical advantages of repairing the PQ include the provision of plate coverage, a protective gliding layer, a well-vascularized coverage of the fracture fragments, and a protective barrier against deep infection in the case of superficial infection. Techniques have been developed to try and improve on the Henry approach. We have developed a surgical approach to volar plating that utilizes the anatomic relationship between brachioradialis and PQ in a way that allows simple and stable reattachment of the PQ muscle. We have termed the technique the "Brachioradialis splitting" approach. We present it here.

  18. [Validity of modified radiological views to detect screw protrusion at the distal radius. A comparative study with computerized tomography].

    PubMed

    Mora-Pascual, F E; Aguilella-Fernández, L

    2013-01-01

    Volar fixed-angle plates (VFAP) are currently widely used for the treatment of extra-articular distal radius fractures. Using these plates has a high risk of articular and dorsal screw protrusion due to their special configuration. The aim of this study is to assess the validity of the standard X-rays, performed with the help of wedged supports, in order to detect articular and dorsal screw protrusion. A comparison with computed tomography (CT) scan imaging has been made. The outcome of 26 patients with distal radius articular fracture, treated with a VFAP, is reported. Good correlation between modified X-rays and CT scan was observed. A sensitivity of 100% for articular protrusion and 66% for dorsal have been obtained. When detecting screw protrusion at the distal radius, the use of wedged supports to perform special X-rays intraoperatively is an effective tool.

  19. [Possible applications of pedicled vascularized bone transplants of the distal radius].

    PubMed

    Sauerbier, M; Bishop, A T

    2001-11-01

    Reverse-flow pedicle vascularized bone grafts (VBGs) from the distal radius may be used for the surgical treatment of carpal fracture nonunions and avascular necrosis. Such grafts remain viable with quantifiable blood flow as demonstrated in a recent canine experiment. In this paper, the vascular anatomy of the distal radius is demonstrated and the surgical technique of VBG harvest is described. Our indications and results for treatment of scaphoid nonunion and Kienböck's disease are discussed and compared with the current literature. Fifteen patients with scaphoid nonunion and nine patients with Kienböck's disease stage IIIa were treated by reverse-flow pedicled VBG. Range of motion and grip strength were measured postoperatively and compared to the contralateral hand in all patients. An outcome questionnaire was used to measure patient's satisfaction and ADL's in the patients with Kienböck's disease. The radiologic diagnostic was performed with conventional X-rays, trispiral tomograms and MRI. In the scaphoid nonunion group, all patients were male, with an average age of 27.6 years. Five patients had prior attempts of autogenous bone grafting which failed. Six patients had a radiographic suggestion of proximal fragment avascular necrosis. All scaphoids healed. Time to union was 11.1 weeks on average. Average follow-up was 36.2 months. Pain relief, range of motion and grip strength were very promising. The treatment of Kienböck's disease was also promising in nine patients. Mean patient age was 31 years, and follow-up averaged 32 months. Six patients had complete pain relief, and three had occasional pain. Grip strength reached 86% of the contralateral side (a 25% improvement from preoperative values). Postoperative MRI demonstrated progressive revascularization with time. The results of treating scaphoid nonunions are promising. The use of vascularized bone graft facilitates rapid, reliable union of established scaphoid nonunion, even with proximal location

  20. Fracture of the ulnar styloid process negatively influences the outcome of paediatric fractures of the distal radius.

    PubMed

    Zoetsch, Silvia; Kraus, Tanja; Weinberg, Annelie M; Heidari, Nima; Lindtner, Richard A; Singer, Georg

    2013-02-01

    In paediatric patients with fractures of the distal radius, the consequences of associated ulnar styloid fractures are often underestimated. These may include persisting pain or functional deficits. The aim of the present study was to report the outcome of these fractures using a modified DASH-Score. All children with distal radius fractures treated in a two years period were analysed; only patients with a concomitant fracture of the ulnar styloid were included in the study.In addition, children with a non-union of the styloid at cast removal were asked to complete a postal questionnaire; the data were compared to those in a group of patients with isolated distal radius fractures. Patients reporting problems and those with a modified DASH score over 0.5 were invited for a long-term follow-up clinical and radiological examination. A concomitant fracture of the ulnar styloid was present in 11% of all distal radius fractures. At the time of cast removal 46 patients (89%) showed a delayed union of the ulnar styloid. The modified DASH Score of these patients at an average of 31 months (range: 24-40 months) was significantly worse (3.8; range: 0-24.2) compared to 0.7 (range 0-27.7) in the patients with isolated radius fractures after a mean of 27 months (range: 21-42 months). At follow-up, 7 patients showed a non-union of the ulnar styloid. Fractures of the base of the styloid process were more likely to develop non-union compared to fractures of its tip. The presence of an ulnar styloid fracture negatively influences the outcome of distal radius fractures. Patients with lesions of the ulnar styloid should be followed until union is observed and/or they are asymptomatic. PMID:23547515

  1. Relationship between Patient Satisfaction and Objective Functional Outcome after Surgical Treatment for Distal Radius Fractures

    PubMed Central

    Chung, Kevin C.; Haas, Ann

    2009-01-01

    Study Design Prospective Cohort. Introduction Patient satisfaction is increasingly used as a metric of health care outcomes. The relationship between patient satisfaction and functional outcomes metrics is understudied. Purpose To determine the minimum recovery needed in grip strength, key pinch strength, and arc of motion needed for patient satisfaction after treatment of distal radius fracture (DRF) with volar locking plating system placement. Methods A prospective cohort of 125 DRF patients was evaluated 3 months after surgery for grip strength, key pinch strength, wrist arc of motion, and satisfaction with hand strength and wrist arc of motion. Receiver operating characteristic (ROC) curves were constructed using patient satisfaction items as the “gold standard” and each functional measure of outcome as a predictor. Results We found that the optimal cut-points to distinguish satisfaction from dissatisfaction occurred when patients had recovered 65% of their grip strength, 87% of their key grip strength, and 95% of the wrist arc of motion, as measured as percents of their uninjured wrists. Conclusions A much greater wrist range of motion must be recovered for patients to be satisfied than what is needed to perform activities of daily living. Level of Evidence Diagnosis Level 2. PMID:19560317

  2. Arthroscopic study of injuries in articular fractures of distal radius extremity

    PubMed Central

    Araf, Marcelo; Mattar, Rames

    2014-01-01

    OBJECTIVE: To analyze the incidence of wrist ligament and cartilage associated fractures of the distal radius, through arthroscopy, correlating with AO/ASIF classification. METHODS: Thirty patients aged between 20 and 50 years old, with closed fracture from groups B and C according to AO/ASIF classification were selected. All of them were submitted to wrist arthroscopy to address intra-articular injuries and reduction and osteosynthesis of the fracture. RESULTS: A high incidence of intra-articular injuries was noticed, and 76.6% of them presented injury of the triangular fibrocartilage complex, 36.6% of the intrinsic scapholunate ligament, 6.6% of the intrinsic triquetrolunate ligament, and 33% articular cartilage injury larger than three millimeters. Patients with fractures from type C according to AO/ASIF classification presented a higher incidence of ligament injuries. CONCLUSION: There is no relationship between the presence of chondral injury and the AO/ASIF classification of the fractures in the cases reported in this study. Level of Evidence III, Non Randomized Controlled Trial. PMID:25061421

  3. Comparison of Risk of Carpal Tunnel Syndrome in Patients with Distal Radius Fractures After 7 Treatments

    PubMed Central

    Zhao, Huan-Li; Wang, Gui-Bin; Jia, Yue-Qing; Zhu, Shi-Cai; Zhang, Feng-Fang; Liu, Hong-Mei

    2015-01-01

    Background To compare risk of carpal tunnel syndrome (CTS) in distal radius fracture (DRF) patients after 7 treatments using bridging external fixation (BrEF), non-bridging external fixation (non-BrEF), plaster fixation, K-wire fixation, dorsal plating fixation, volar plating fixation, and dorsal and volar plating by performing a network meta-analysis. Material/Methods An exhaustive search of electronic databases identified randomized controlled trails (RCTs) closely related to our study topic. The published articles were screened, based on predefined inclusion and exclusion criteria, to select high-quality studies for the present network meta-analysis. Data extracted from the selected studies were analyzed using STATA version 12.0 software. Results The literature search and selection process identified 12 eligible RCTs that contained a total of 1370 DRF patients (394 patients with BrEF, 377 patients with non-BrEF, 89 patients with K-wire fixation, 192 patients with plaster fixation, 42 patients with dorsal plating fixation, 152 patients with volar plating fixation, and 124 patients with dorsal and volar plating fixation). Our network meta-analysis results demonstrated no significant differences in CTS risk among the 7 treatments (P>0.05). The value of surface under the cumulative ranking curve (SUCRA), however, suggested that dorsal plating fixation is the optimal treatment, with the lowest risk of CTS in DRF patients (dorsal plating fixation: 89.2%; dorsal and volar plating: 57.8%; plaster fixation: 50.9%; non-BrEF: 50.6%; volar plating fixation: 39.6%; BrEF: 38.4%; K-wire fixation: 23.6%). Conclusions Our network meta-analysis provides evidence that dorsal plating fixation significantly decreases the risk of CTS and could be the method of choice in DRF patients. PMID:26391617

  4. [Retrospective analysis of consecutively treated distal radius fractures with the external fixator].

    PubMed

    Melik, N; Togninalli, D; Biegger, P

    1994-12-01

    The purpose of this study was to determine retrospectively some subjective and objective parameters following the operative treatment of 32 patients with "complex" (intraarticular and/or comminuted) fractures of the distal radius using the small AO external fixation device. The mean follow-up period was 20 months (minimum 4, maximum 48) and the mean age of the subjects was 62 years (minimum 27, maximum 91). Subjective results such as "general feeling", mobility, strength and pain, expressed with a scoring system (% of maximum obtainable points), showed an overall good result and ranged between 71% (pain), 81% (strength) and 91% (mobility and "general feeling"). Regarding the objective results, no major skin or soft tissue distress (Sudeck dystrophy) was noted. However, there was a general tendency towards a mobility deficit of the wrist operated on, which was statistically significant (P < 0.01) for flexion, extension, supination and abduction (respectively, -17.7%, -12.4%, -7.1% and -12.5%). The late standard radiological and lateral controls showed a mean radial angle of +2.13 degrees (B or lateral radial angle) and +23.13 degrees (A or AP angle), respectively. The analysis of data, as expressed by time after operation (< or > than 10 months), showed no relevant difference between the two groups (age of both similar), as expressed by age (< or > than 60 years); the data only showed differences in strength and pain (scores by 92% vs 82% for force and 92% vs 76% for pain) and in flexion and extension (-22.8% and -14%, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7855610

  5. Utilization of Post-Acute Care following Distal Radius Fracture among Medicare Beneficiaries

    PubMed Central

    Zhong, Lin; Mahmoudi, Elham; Giladi, Aviram M.; Shauver, Melissa; Chung, Kevin C.; Waljee, Jennifer F.

    2016-01-01

    Purpose To examine the utilization and cost of post-acute care following isolated distal radius fractures (DRF) among Medicare beneficiaries. Methods We examined utilization of post-acute care among Medicare beneficiaries who experienced an isolated DRF (n=38,479) during 2007 using 100% Medicare claims data. We analyzed the effect of patient factors on hospital admission following DRF and the receipt of post-acute care delivered by skilled nursing facilities (SNFs), inpatient rehabilitation facilities (IRFs), home healthcare agencies (HHAs), and outpatient OT/PT for the recovery of DRF. Results In this cohort of isolated DRF patients, 1,694 (4.4%) were admitted to hospitals following DRF, and 20% received post-acute care. Women and patients with more comorbid conditions were more likely to require hospital admission. The utilization of post-acute care was higher among women, patients who resided in urban areas, and patients of higher socioeconomic status. The average cost per patient of post-acute care services from IRFs and SNFs ($15,888/patient) was significantly higher than the average cost other aspects of DRF care and accounted for 69% of the total DRF-related expenditure among patients who received inpatient rehabilitation. Conclusions Sociodemographic factors, including sex, socioeconomic status, and age, were significantly correlated with the use of post-acute care following isolated DRFs, and post-acute care accounted for a substantial proportion of the total expenditures related to these common injuries among the elderly. Identifying patients who will derive the greatest benefit from post-acute care can inform strategies to improve the cost-efficiency of rehabilitation and optimize scarce healthcare resources. Level of evidence Therapeutic, III PMID:26527599

  6. SURGICAL TREATMENT OF DISTAL RADIUS FRACTURES WITH A VOLAR LOCKED PLATE: CORRELATION OF CLINICAL AND RADIOGRAPHIC RESULTS

    PubMed Central

    Xavier, Claudio Roberto Martins; Dal Molin, Danilo Canesin; dos Santos, Rafael Mota Marins; dos Santos, Roberto Della Torre; Neto, Julio Cezar Ferreira

    2015-01-01

    Objectives: To analyze and correlate the clinical and radiographic results from patients with distal radius fractures who underwent surgical treatment with a fixed-angle volar locked plate. Methods: Sixty-four patients with distal radius fractures were evaluated. They all underwent surgical treatment with a volar locked plate for the distal radius, with a minimum of six months of postoperative follow-up. They underwent a physical examination that measured range of motion and grip strength, answered the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and underwent radiographic examination. Results: In the physical examination on the patients, all the range-of-motion measurements were reduced. Grip strength measured in kgf was on average 85.8% of the strength on the unaffected side. The mean DASH score was 15.99. A significant relationship was found between lower DASH scores and losses of extension and grip strength. On the radiographs, the mean values in relation to the unfractured side were 84.0% for radial inclination, 85.4% for radial length and 86.8% for volar deviation of the radius. Loss of radial length was correlated with losses of extension and grip strength. PMID:27027046

  7. Possibility of Fixation of a Distal Radius Fracture With a Volar Locking Plate Through a 10 mm Approach.

    PubMed

    Naito, Kiyohito; Zemirline, Ahmed; Sugiyama, Yoichi; Obata, Hiroyuki; Liverneaux, Philippe; Kaneko, Kazuo

    2016-06-01

    The management of distal radius fractures has dramatically improved due to the development of a locking plate system. In addition, mini-invasive surgery has been performed in a lot of surgical fields in recent years. The aim of the present study is to investigate the possibility of fixation of a distal radius fracture with a volar locking plate through a 10 mm approach. Eighteen patients with distal radius fracture (mean age: 66 y; range, 28 to 88 y; 8 males and 10 females) were operated on using a volar locking plate. The incision for plating was always 10 mm long. The clinical, cosmetic, and radiologic outcomes were investigated. At 3 months' follow-up, the range of motion of the wrist joint was 67.5 degrees in flexion, 65.6 degrees in extension, 88.3 degrees in pronation, and 88.3 degrees in supination. The % grip strength compared to the healthy side ranged from 35% to 100%. The VAS, Q-DASH, and modified Mayo scores were 0.7, 8.5, and 93.3, respectively (excellent in all 18 patients). Bone union was achieved on plain x-ray radiography and cosmetic problems were satisfied in all patients. Our results suggest that it is possible to achieve fixation of a distal radius fracture with a volar locking plate through a 10 mm approach. However, its applicability to surgery must be carefully examined. If any difficulties in plate installation or approach occur during this intervention, it will be necessary to consider switching to a conventional approach. We believe that surgeons must not adhere to a mini-invasive approach. PMID:27015408

  8. Surgical Treatment of Unstable Distal Radius Fractures With a Volar Variable-Angle Locking Plate: Clinical and Radiological Outcomes

    PubMed Central

    Khatri, Kavin; Sharma, Vijay; Farooque, Kamran; Tiwari, Vivek

    2016-01-01

    Background Unstable distal end radius fractures are difficult to manage and so various treatment modalities have been described. The use of variable-angle locking plates is promoted for the management of these fractures. Objectives This study aimed to evaluate the functional and radiological outcomes in unstable distal end radius fractures treated with variable-angle locking plates. Patients and Methods We reviewed 23 unstable distal end radius fractures that were treated at our institution with volar variable-angle locking plates. The mean age of the patients was 32.82 ± 11.81 years (range 19 to 62) and the mean duration of follow-up was 11.04 ± 2.47 months (range 6 to 15). All of the patients underwent open reduction and internal fixation with a variable-angle locking plate. Radiological parameters such as radial inclination, length, tilt, and ulnar variance were measured at six weeks and at the final follow-up. The functional evaluation was conducted by measuring the range of motion at the wrist joint as well as the grip strength. Gartland and Werley’s demerit scoring system was used to assess the final outcome. Results There were two cases of superficial infection that responded to oral antibiotics. One patient had developed a hypertrophic scar, while another had carpal tunnel syndrome that was conservatively managed. There was a significant improvement in the functional indices from six weeks to the final follow-up, while the radiological parameters were maintained. According to Gartland and Werley, excellent results were reported in 65.2% cases, while good results were present in 35% cases. Conclusions The use of variable-angle locking plates in treating unstable distal end radius fractures is associated with excellent to good functional outcomes with minimal complications.

  9. Osteosynthesis in Distal Radius Fractures with Conventional Bridging External Fixator; Tips and Tricks for Getting Them Right

    PubMed Central

    Chilakamary, Vamshi Krishna; Koppolu, Kiran Kumar; Rapur, Shivaprasad

    2016-01-01

    Background Distal radius fractures are the commonest fractures occurring in the upper extremity, accounting for 15-20% of patients treated in emergency department. Although distal radial fractures were described 200 years ago, they still remain as unsolved fractures with no clear guidelines. It is often reported that anatomical reduction has a bearing on the functional outcome. Aim To study the management of distal end radius fracture by utilizing the principle of ligamentotaxis where in the reduction obtained by closed means is maintained by external fixator till solid bony union occurs. Materials and Methods A total of 26 cases were selected for study by scrutiny of the inclusion and exclusion criteria. Most of our cases were treated with external fixator within 8 hrs of injury. Small A.O external fixator (bridging ex-fix) with 2 pins each in radius and 2nd metacarpal percutaneously was used for all the cases. Selective k wire fixation was done in cases of instability. Fixator was removed after 6 weeks. Guided physiotherapy was ensured in all the cases. Patients were followed up for an average of 9 months. Results Modified Gartland and Werley scoring system was used to evaluate the overall functional results. Excellent to good results were achieved in 88.45% of our cases while fair result was in 11.54 %. One case had pin loosening and two other cases had malunion. Conclusion External fixator used for ligamentotaxis is an effective method of treating unstable extraarticular and complex intraarticular fractures of distal radius. Improved anatomical restoration with early rehabilitation has produced favourable functional outcome in our series. The complications like pin tract infection is rare due to the availability of superior antibiotics and sterile surgical technique. complications like wrist and finger stiffness has improved with physiotherapy. PMID:26894133

  10. Surgical Treatment of Unstable Distal Radius Fractures With a Volar Variable-Angle Locking Plate: Clinical and Radiological Outcomes

    PubMed Central

    Khatri, Kavin; Sharma, Vijay; Farooque, Kamran; Tiwari, Vivek

    2016-01-01

    Background Unstable distal end radius fractures are difficult to manage and so various treatment modalities have been described. The use of variable-angle locking plates is promoted for the management of these fractures. Objectives This study aimed to evaluate the functional and radiological outcomes in unstable distal end radius fractures treated with variable-angle locking plates. Patients and Methods We reviewed 23 unstable distal end radius fractures that were treated at our institution with volar variable-angle locking plates. The mean age of the patients was 32.82 ± 11.81 years (range 19 to 62) and the mean duration of follow-up was 11.04 ± 2.47 months (range 6 to 15). All of the patients underwent open reduction and internal fixation with a variable-angle locking plate. Radiological parameters such as radial inclination, length, tilt, and ulnar variance were measured at six weeks and at the final follow-up. The functional evaluation was conducted by measuring the range of motion at the wrist joint as well as the grip strength. Gartland and Werley’s demerit scoring system was used to assess the final outcome. Results There were two cases of superficial infection that responded to oral antibiotics. One patient had developed a hypertrophic scar, while another had carpal tunnel syndrome that was conservatively managed. There was a significant improvement in the functional indices from six weeks to the final follow-up, while the radiological parameters were maintained. According to Gartland and Werley, excellent results were reported in 65.2% cases, while good results were present in 35% cases. Conclusions The use of variable-angle locking plates in treating unstable distal end radius fractures is associated with excellent to good functional outcomes with minimal complications. PMID:27679785

  11. Bone Mineral Density and Prevalence of Osteoporosis in Postmenopausal Korean Women with Low-Energy Distal Radius Fractures

    PubMed Central

    2016-01-01

    The aim of this study was to evaluate the bone mineral density and the prevalence of osteoporosis in postmenopausal Korean women with low-energy distal radius fractures and compared with those of aged-matched normal Korean women. Two hundred and six patients with distal radius fractures between March 2006 and March 2010 were included in this study. Patients were divided into three groups by age; group 1 (50-59 years), group 2 (60-69 years), and group 3 (70-79 years). Controls were age-matched normal Korean women. The bone mineral density values at all measured sites, except for the spine, were significantly lower in group 1 than those of control. While the bone mineral density values in group 2 and 3 were lower than those of controls, these differences were not statistically significant. All groups had significantly higher prevalence of osteoporosis at the Ward’s triangle; however, at the spine, femoral neck and trochanteric area it was not significantly different from those of age-matched controls. Although the prevalence of osteoporosis of the postmenopausal women with low-energy distal radius fractures may not be higher than that of the control, osteoporosis should be evaluated especially in younger postmenopausal patients to prevent other osteoporotic hip and/or spine fractures. PMID:27247508

  12. Supination and Pronation Strength Deficits Persist at 2-4 Years after Treatment of Distal Radius Fractures.

    PubMed

    Ploegmakers, Joris; The, Bertram; Wang, Allan; Brutty, Mike; Ackland, Tim

    2015-10-01

    Forearm rotation is a key function in the upper extremity. Following distal radius fracture, residual disability may occur in tasks requiring forearm rotation. The objectives of this study are to define pronation and supination strength profiles tested through the range of forearm rotation in normal individuals, and to evaluate the rotational strength profiles and rotational strength deficits across the testing range in a cohort of patients treated for distal radius fracture associated with an ulnar styloid base fracture. In a normative cohort of 29 subjects the supination strength profile showed an increasing linear relationship from supination to pronation. Twelve subjects were evaluated 2-4 years after anatomical open reduction and volar plate fixation of a distal radius fracture. The injured wrist was consistently weaker (corrected for hand dominance) in both supination and pronation strength in all testing positions, with the greatest loss in 60 degrees supination. Mean supination strength loss across all testing positions was significantly correlated with worse PRWE scores, highlighting the importance of supination in wrist function.

  13. Statistical analysis on the concordance of the radiological evaluation of fractures of the distal radius subjected to traction☆

    PubMed Central

    Machado, Daniel Gonçalves; da Cruz Cerqueira, Sergio Auto; de Lima, Alexandre Fernandes; de Mathias, Marcelo Bezerra; Aramburu, José Paulo Gabbi; Rodarte, Rodrigo Ribeiro Pinho

    2016-01-01

    Objective The objective of this study was to evaluate the current classifications for fractures of the distal extremity of the radius, since the classifications made using traditional radiographs in anteroposterior and lateral views have been questioned regarding their reproducibility. In the literature, it has been suggested that other options are needed, such as use of preoperative radiographs on fractures of the distal radius subjected to traction, with stratification by the evaluators. The aim was to demonstrate which classification systems present better statistical reliability. Results In the Universal classification, the results from the third-year resident group (R3) and from the group of more experienced evaluators (Staff) presented excellent correlation, with a statistically significant p-value (p < 0.05). Neither of the groups presented a statistically significant result through the Frykman classification. In the AO classification, there were high correlations in the R3 and Staff groups (respectively 0.950 and 0.800), with p-values lower than 0.05 (respectively <0.001 and 0.003). Conclusion It can be concluded that radiographs performed under traction showed good concordance in the Staff group and in the R3 group, and that this is a good tactic for radiographic evaluations of fractures of the distal extremity of the radius. PMID:26962498

  14. Limb-salvage treatment of en-block resected distal femoral tumors with endoprosthesis of all-polyethylene tibial component: a 9-year follow-up study

    PubMed Central

    Tang, Fan; Zhou, Yong; Min, Li; Zhang, Wenli; Shi, Rui; Luo, Yi; Duan, Hong; Tu, Chongqi

    2016-01-01

    Objective To evaluate the medium-term outcome of limb-salvage surgery using all-polyethylene tibial endoprosthetic replacement following en-block resection for distal femoral tumors. Methods Forty-nine patients with distal femoral tumor were treated between June 2006 and June 2012. The follow-up period was 6–110 months (average 53.4 months). The prosthetic survival was analyzed using the Kaplan–Meier method. The classification of failure of limb salvage after reconstructive surgery for bone tumors was adapted. Limb function was evaluated with the scoring system of the Musculoskeletal Tumor Society (MSTS). Results Complications were observed in six cases (12.2%). Four suffered infection around the prosthesis, of which two cases were treated with debridement, drainage, and antibiotics without removal of the prosthesis, and the other two cases underwent amputation. Two cases were identified as radiographically loose at 7 year follow-up and did not require revision surgery. One patient underwent amputation due to local recurrence. Failure of limb salvage occurred in nine cases (18.4%), of which two cases were of type 1A, two cases of type 2B, three cases of type 4A, one case of type 4B, and one case of type 5A. The mean MSTS score was 84.3%. Twelve cases died due to distant metastases (24.5%), and the average survival time for these patients was 13.5 months. Thirty-seven patients survived (75.5%), for whom the average follow-up time was 66.3 months and the 5-year prosthetic survival rate was 88.2%. Conclusion The outcome of medium-term and long-term clinical follow-up was satisfactory. All-polyethylene tibial endoprosthetic replacement following en-block resection can be an alternative method of limb salvage for distal femoral tumors.

  15. Limb-salvage treatment of en-block resected distal femoral tumors with endoprosthesis of all-polyethylene tibial component: a 9-year follow-up study

    PubMed Central

    Tang, Fan; Zhou, Yong; Min, Li; Zhang, Wenli; Shi, Rui; Luo, Yi; Duan, Hong; Tu, Chongqi

    2016-01-01

    Objective To evaluate the medium-term outcome of limb-salvage surgery using all-polyethylene tibial endoprosthetic replacement following en-block resection for distal femoral tumors. Methods Forty-nine patients with distal femoral tumor were treated between June 2006 and June 2012. The follow-up period was 6–110 months (average 53.4 months). The prosthetic survival was analyzed using the Kaplan–Meier method. The classification of failure of limb salvage after reconstructive surgery for bone tumors was adapted. Limb function was evaluated with the scoring system of the Musculoskeletal Tumor Society (MSTS). Results Complications were observed in six cases (12.2%). Four suffered infection around the prosthesis, of which two cases were treated with debridement, drainage, and antibiotics without removal of the prosthesis, and the other two cases underwent amputation. Two cases were identified as radiographically loose at 7 year follow-up and did not require revision surgery. One patient underwent amputation due to local recurrence. Failure of limb salvage occurred in nine cases (18.4%), of which two cases were of type 1A, two cases of type 2B, three cases of type 4A, one case of type 4B, and one case of type 5A. The mean MSTS score was 84.3%. Twelve cases died due to distant metastases (24.5%), and the average survival time for these patients was 13.5 months. Thirty-seven patients survived (75.5%), for whom the average follow-up time was 66.3 months and the 5-year prosthetic survival rate was 88.2%. Conclusion The outcome of medium-term and long-term clinical follow-up was satisfactory. All-polyethylene tibial endoprosthetic replacement following en-block resection can be an alternative method of limb salvage for distal femoral tumors. PMID:27695342

  16. Distal radius strength: a comparison of DXA-derived vs pQCT-measured parameters in adolescent females.

    PubMed

    Dowthwaite, Jodi N; Hickman, Rebecca M; Kanaley, Jill A; Ploutz-Snyder, Robert J; Spadaro, Joseph A; Scerpella, Tamara A

    2009-01-01

    Although quantitative computed tomography (QCT) is considered the gold standard for in vivo densitometry, dual-energy X-ray absorptiometry (DXA) scans assess larger bone regions and are more appropriate for pediatric longitudinal studies. Unfortunately, DXA does not yield specific bone architectural output. To address this issue in healthy, postmenarcheal girls, Sievänen's distal radius formulae [1996] were applied to derive indices of bone geometry, volumetric bone mineral density (vBMD), and strength from DXA data; results were compared to peripheral quantitative computed tomography (pQCT) output. Contemporaneous scans were performed on the left, distal radii of 35 gymnasts, ex-gymnasts, and nongymnasts (aged 13.3-20.4 yr, mean 16.6 yr). For 4% and 33% regions, pQCT measured cross-sectional areas (CSAs) and vBMD; comparable DXA indices were generated at ultradistal and 1/3 regions. Index of structural strength in axial compression was calculated from 4% pQCT and DXA output for comparison; 33% pQCT strength-strain index was compared to 1/3 DXA section modulus. Sievänen DXA indices were significantly, positively correlated with pQCT output (R=+0.61 to +0.98; p<0.0001). At the distal radius, in healthy postmenarcheal girls, Sievänen's method yielded potentially useful DXA indices of diaphyseal cortical CSA and bone strength at both the diaphysis (section modulus) and the metaphysis (index of structural strength in axial compression).

  17. Cortical porosity is higher in boys compared with girls at the distal radius and distal tibia during pubertal growth: an HR-pQCT study.

    PubMed

    Nishiyama, Kyle K; Macdonald, Heather M; Moore, Sarah A; Fung, Tak; Boyd, Steven K; McKay, Heather A

    2012-02-01

    The aim of this study was to determine the sex- and maturity-related differences in bone microstructure and estimated bone strength at the distal radius and distal tibia in children and adolescents. We used high-resolution pQCT to measure standard morphological parameters in addition to cortical porosity (Ct.Po) and estimated bone strength by finite element analysis. Participants ranged in age from 9 to 22 years (n = 212 girls and n = 186 boys) who were scanned annually for either one (11%) or two (89%) years at the radius and for one (15%), two (39%), or three (46%) years at the tibia. Participants were grouped by the method of Tanner into prepubertal, early pubertal, peripubertal, and postpubertal groups. At the radius, peri- and postpubertal girls had higher cortical density (Ct.BMD; 9.4% and 7.4%, respectively) and lower Ct.Po (-118% and -56%, respectively) compared with peri- and postpubertal boys (all p < 0.001). Peri- and postpubertal boys had higher trabecular bone volume ratios (p < 0.001) and larger cortical cross-sectional areas (p < 0.05, p < 0.001) when compared with girls. Based upon the load-to-strength ratio (failure load/estimated fall force), boys had lower risk of fracture than girls at every stage except during early puberty. Trends at the tibia were similar to the radius with differences between boys and girls in Ct.Po (p < 0.01) and failure load (p < 0.01) at early puberty. Across pubertal groups, within sex, the most mature girls and boys had higher Ct.BMD and lower Ct.Po than their less mature peers (prepuberty) at both the radius and tibia. Girls in early, peri-, and postpubertal groups and boys in peri- and postpubertal groups had higher estimates of bone strength compared with their same-sex prepubertal peers (p < 0.001). These results provide insight into the sex- and maturity-related differences in bone microstructure and estimated bone strength.

  18. Recent Update in the Diagnosis and Treatment of Bone Frailty in Patients with a Distal Radius Fracture.

    PubMed

    Shin, Young Ho; Gong, Hyun Sik

    2016-10-01

    Distal radius fracture (DRF) is the most common upper extremity fracture in the elderly. Patients with a DRF have a two to fourfold higher risk of a subsequent fracture than those with no history of fractures, and DRFs occur on average 15 years earlier than hip fractures. Therefore, patients with a DRF offer physicians an important opportunity to diagnose and treat osteoporosis to prevent a secondary fracture. In this review, we provide recent update in the diagnosis and treatment of bone frailty in patients with a DRF. PMID:27595946

  19. Displaced Intra-Articular Fractures of the Distal Radius: Open Reduction With Internal Fixation Versus Bridging External Fixation

    PubMed Central

    Fakoor, Mohammad; Fakoor, Morteza; Mohammadhoseini, Payam

    2015-01-01

    Background: Distal radius fracture is common in all ages. Mobility and wrist function is important. The choice of treatment should aim for optimal function with minimal complications. Objectives: In this study we compared two surgical approaches, open reduction and internal fixation (ORIF) and closed reduction with external fixation (CR + EF), for treatment of intra-articular distal radius fractures. Patients and Methods: Ninety-four patients with distal radius fracture (type 3, 4 and 5 Fernandez classification) were treated with two surgical methods (ORIF and CR + EF); 55 were treated with CR + EF and 39 were treated with ORIF by different surgeons. All patients were assessed at the end of the first, third and sixth week; and then after the third, sixth and 12th month. At the end of the follow-up, all patients completed the Michigan hand outcome questionnaire (MHOQ). We compared radiological parameters of distal radius, range of motion (ROM) of the wrist, duration of rehabilitation, complication and patient satisfaction of the methods. Results: In our study, radiological findings for the ORIF group were radial inclination (RI): 19.35, radial length (RL): 10.35, radial tilt (RT): 8.92, and ulnar variance (UV): 1.64, while for the CR + EF group these were RI: 15.13, RL: 8, RT: 4.78, and UV: 0.27. The ROM for ORIF were flexion/extension (F/E): 137, Radial/Ulnar deviation (R/U): 52, and Supination/Pronation (S/P): 141, while for the CR + EF group these were F/E: 117, R/U: 40 and S/P: 116. Michigan hand outcome score for ORIF was 75% and for Ext. fix was 60%. The rate of complication with the ORIF method was 58% and in Ext. fix this was 69%. The patients in CR + EF had more than the ORIF course of physiotherapy and rehabilitation. Conclusions: In comparison of ORIF and CR + EF, all results including functional score, clinical and radiologic criteria were in favor of the ORIF method while there were less complications with this method. We believe that ORIF is a better

  20. Sex- and Maturity-Related Differences in Cortical Bone at the Distal Radius and Midshaft Tibia Evaluated by Quantitative Ultrasonography.

    PubMed

    Baptista, Fátima; Rebocho, Lurdes M; Cardadeiro, Graça; Zymbal, Vera; Rosati, Nicoletta

    2016-09-01

    Boys usually have higher values of bone mineral density measured by dual-energy X-ray absorptiometry than girls, but contradictorily also have a greater incidence of fractures during growth. The purpose of this study was to investigate sex- and maturity-related differences in bone speed of sound (SoS) at the radius and tibia in a sample of 625 healthy children aged 10-14 y and to analyze the contributions of physical activity (PA) to possible dissimilarities. Radial and tibial SoS was evaluated by quantitative ultrasound, maturity was estimated as the years of distance from the peak height velocity age, and PA was assessed by accelerometry. Comparisons between sexes and maturity groups (low: below average [<-2.5 y], high: average or above [≥-2.5 y]) were made by two-sample t-tests with unequal variances. Girls in the high-maturity group had higher SoS at the radius and tibia compared with girls in the low-maturity group (p < 0.001). There were no SoS differences at the radius or tibia between the high- and low-maturity groups in boys. Within high-maturity children, girls had higher SoS than boys at the radius and tibia (p < 0.001). There were no differences at the radius and tibia between girls and boys with low maturity. The results were not modified after controlling for PA. Regardless of PA, the results provide insight into sex- and maturity-related differences in bone SoS at the distal radius and midshaft tibia from maturity less than 2.5 y from the peak height velocity age, with boys having lower SoS. PMID:27181690

  1. Sex- and Maturity-Related Differences in Cortical Bone at the Distal Radius and Midshaft Tibia Evaluated by Quantitative Ultrasonography.

    PubMed

    Baptista, Fátima; Rebocho, Lurdes M; Cardadeiro, Graça; Zymbal, Vera; Rosati, Nicoletta

    2016-09-01

    Boys usually have higher values of bone mineral density measured by dual-energy X-ray absorptiometry than girls, but contradictorily also have a greater incidence of fractures during growth. The purpose of this study was to investigate sex- and maturity-related differences in bone speed of sound (SoS) at the radius and tibia in a sample of 625 healthy children aged 10-14 y and to analyze the contributions of physical activity (PA) to possible dissimilarities. Radial and tibial SoS was evaluated by quantitative ultrasound, maturity was estimated as the years of distance from the peak height velocity age, and PA was assessed by accelerometry. Comparisons between sexes and maturity groups (low: below average [<-2.5 y], high: average or above [≥-2.5 y]) were made by two-sample t-tests with unequal variances. Girls in the high-maturity group had higher SoS at the radius and tibia compared with girls in the low-maturity group (p < 0.001). There were no SoS differences at the radius or tibia between the high- and low-maturity groups in boys. Within high-maturity children, girls had higher SoS than boys at the radius and tibia (p < 0.001). There were no differences at the radius and tibia between girls and boys with low maturity. The results were not modified after controlling for PA. Regardless of PA, the results provide insight into sex- and maturity-related differences in bone SoS at the distal radius and midshaft tibia from maturity less than 2.5 y from the peak height velocity age, with boys having lower SoS.

  2. [Clinical results following conservative and surgical treatment of osteoporotic distal radius fractures in the elderly : Overview of best available evidence].

    PubMed

    Bartl, C; Stengel, D; Gülke, J; Gebhard, F

    2016-09-01

    Fractures of the distal radius in elderly patients increasingly contribute to the workload in emergency departments worldwide. There is still no consensus about the best treatment option, e. g. closed reduction and cast stabilization, percutaneous pinning, external fixation or open reduction and internal fixation with volar locking plates (ORIF). In addition, the influence of pharmacological antiosteoporotic treatment (e. g. bisphosphonates) is unclear. In this overview five comparative studies were analyzed, which had been identified in a previous systematic review. The evaluation included 3 cohort studies and 2 randomized trials enrolling a total of 515 patients. A clinical or statistical advantage of ORIF over conservative treatment with respect to DASH scores 12 months after the index fracture event could not be demonstrated with a mean difference of 0.25 (95 % confidence interval CI -0.57-1.07). According to current best scientific evidence from preclinical and clinical investigations, antiosteoporotic medication does not have an unfavorable influence on fracture healing and should be continued due to its proven effectiveness in reducing subsequent osteoporotic fractures. Following distal radius fractures in elderly patients with clinical risk factors, an osteoporosis screening should be routine practice and a specific therapy should be initiated if the fracture risk is increased. PMID:27481355

  3. Reduction of multi-fragment fractures of the distal radius using atlas-based 2D/3D registration

    NASA Astrophysics Data System (ADS)

    Gong, Ren Hui; Stewart, James; Abolmaesumi, Purang

    2009-02-01

    We describe a method to guide the surgical fixation of distal radius fractures. The method registers the fracture fragments to a volumetric intensity-based statistical anatomical atlas of distal radius, reconstructed from human cadavers and patient data, using a few intra-operative X-ray fluoroscopy images of the fracture. No pre-operative Computed Tomography (CT) images are required, hence radiation exposure to patients is substantially reduced. Intra-operatively, each bone fragment is roughly segmented from the X-ray images by a surgeon, and a corresponding segmentation volume is created from the back-projections of the 2D segmentations. An optimization procedure positions each segmentation volume at the appropriate pose on the atlas, while simultaneously deforming the atlas such that the overlap of the 2D projection of the atlas with individual fragments in the segmented regions is maximized. Our simulation results shows that this method can accurately identify the pose of large fragments using only two X-ray views, but for small fragments, more than two X-rays may be needed. The method does not assume any prior knowledge about the shape of the bone and the number of fragments, thus it is also potentially suitable for the fixation of other types of multi-fragment fractures.

  4. Comparison of treatment of unstable intra articular fractures of distal radius with locking plate versus non-locking plate fixation

    PubMed Central

    Kumar, Sunil; Chopra, R.K.; Sehrawat, Sunil; Lakra, Akshay

    2014-01-01

    Introduction Unstable intra articular fractures of distal radius are frequently being managed with open reduction and internal fixation. Of late in some biomechanical studies locking plates have been shown to be better in terms of maintenance of radiological parameters in comparison to non-locking plates. We conducted this study to know whether this biomechanical superiority of locking plates is converted in to better clinical outcomes. Materials and methods A study was conducted in 60 patients (30 in each group) with unstable intra articular fractures of distal radius who were treated by open reduction and internal fixation with locking plates and non-locking plates. Patients were evaluated for radiological parameters (intra articular step off, radial height, radial tilt, volar tilt) and functional parameters (flexion, extension, radial deviation, ulnar deviation, pronation, supination grip strength) at two year follow up. Overall outcome was evaluated by scoring systems of Gartland and Werley and modified Green O' Brien. Results The change in radiological parameters from immediate post op to latest at two year in locking plate group was not significant for radial height, radial tilt, volar tilt, but ulnar variance whereas in non-locking plate there was significant change in radial height, volar tilt, ulnar variance but no significant change in radial inclination. In clinical and functional outcome no significant difference was found at two year follow up. Conclusions Locking plates maintain the radiological parameters better than non-locking plates but functional outcome are same for both plates at two year after surgery. PMID:25983474

  5. External fixation of intra-articular fracture of the distal radius in young and old adults.

    PubMed

    Huch, K; Hünerbein, M; Meeder, P J

    1996-01-01

    Forty patients (18-89 years old, mean 58 years) with comminuted intra-articular fractures of the distal radial end (AO-type C 2 or C 3) treated with external fixation could be followed for an average of 2.3 years. After 3 weeks, the distraction was released, and after another 3 weeks, the device was removed. Complications seen were one malunion, one radial shaft fracture caused by excentric drilling of a Schanz screw, one Sudeck atrophy, and one subcutaneous pin-track infection. Radial and ulnar deviations were reduced to 52% and 71% of the untreated wrist, whereas the range of motion in the other planes reached about 80% or more of the healthy side. In all, 82.5% of the patients showed good or excellent radiological and functional results. This study demonstrates that external fixation of distal radial C 2 and 3 fractures for 6 weeks results in good recovery for young patients and elderly patients with osteoporosis. PMID:8775708

  6. Evidence based postoperative treatment of distal radius fractures following internal locking plate fixation.

    PubMed

    Klein, S M; Prantl, L; Koller, M; Vykoukal, J; Dolderer, J H; Graf, S; Nerlich, M; Loibl, M; Geis, S

    2015-01-01

    Originally, the treatment method of choice for distal radial fractures (DRF) has been a non-operative approach with six to eight weeks of plaster casting. The introduction of volar locking plate systems at the beginning of the 21 st century has pushed trends towards open reduction and internal fixation (ORIF). While the introduction of fixed angle locking plates together with the increasing knowledge on wrist function and related variable outcomes has led to consensus that operative fixation in instable DRF is the treatment method of choice, there is no agreement on a postoperative care of these injuries. The authors will discuss the available evidence for current concepts of postoperative treatment of DRFs following fixed angle fixation under socioeconomical, biomechanical and burden of disease aspects. Further, relevant randomized controlled trials are evaluated with regard to applied postoperative treatment regimes and related risks for complications.

  7. [Secondary dislocations in fractures of the distal end of the radius].

    PubMed

    Zdun, H; Kanchanlall, W

    1990-01-01

    In the group of 31 patients treated by immobilization of the forearm we observed 71% of secondary dislocations and in group of 46 with the full-arm plaster 65% of secondary dislocation occurred. In the group of 20 patients with the full-arm plaster and the X-ray done between the 7th and 10th day after reduction to correct possible dislocation, followed always by the new, similar plaster cast, we observed 40% of secondary dislocations. Whenever the full-arm plaster was used Sudeck syndrome was observed very rarely. No direct relationship between kind of plaster used and the degree of shortening of the radius length after healing of the fracture was found. Comminuted fractures and osteoporosis are in favour for secondary dislocations. PMID:1369865

  8. Comparison between cast immobilization versus volar locking plate fixation of distal radius fractures in active elderly patients, the Asian perspective.

    PubMed

    Chan, Ying-Ho; Foo, Tun-Lin; Yeo, Chong-Jin; Chew, Winston Yoon-Chong

    2014-01-01

    Displaced distal radius fractures in active elderly patients with high functional demand present a clinical dilemma because current evidence is equivocal in the recommendation of treatment. Internal fixation is an increasingly popular option with proposed superior results. Our study aims to evaluate the results among a population of active elderly patients with displaced fractures managed with either cast immobilization or internal fixation with volar locking plate. Seventy-five patients (35 cast immobilization and 40 internal fixation) with mean age of 74 ± 7.5 years with minimum of 12 months follow-up were studied. The radiological and clinical parameters were assessed at three, six, and 12 months. Functional outcomes (DASH, Green-O'Brien) were assessed at 12 months. Patients who underwent surgery regain wrist motion and grip strength earlier, but this was not statistically significant after six months.

  9. WHAT IS THE BEST RADIOGRAPHIC VIEW FOR “DIE PUNCH” DISTAL RADIUS FRACTURES? A CADAVER MODEL STUDY

    PubMed Central

    Falcochio, Diego Figueira; Crepaldi, Bruno Eiras; Trindade, Christiano Augusto; da Costa, Antonio Carlos; Chakkour, Ivan

    2015-01-01

    Objective: the aim of this study is try to show the best view for distal radius fractures so called die-punch fractures. Methods: There has been used a human cadaver radius bone from the Salvador Arena Tissue Bank. This bone was cleaned up after removing the soft tissues and osteotomies created displaced lunate fossa fractures of 0, 1, 2, 3 and 5 mm. We have fixed this fragment with adhesive tape. Then the joint deviation were significantly increased with step-offs of 1 mm. Radiographs were then taken into 5 different positions: postero-anterior view, lateral view, oblique views and tangencial view for each of the deviations. The resulting lunate fossa depression in each X-ray film was analyzed by the AutoCAD 2010® software. Results: The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees. The pronated oblique view was the best to see the 2mm degrees and the oblique supinated view wasn't able to see the degrees between 1 and 2mm. Conclusion: The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees. PMID:27027079

  10. Volar locking distal radius plates show better short-term results than other treatment options: A prospective randomised controlled trial

    PubMed Central

    Drobetz, Herwig; Koval, Lidia; Weninger, Patrick; Luscombe, Ruth; Jeffries, Paula; Ehrendorfer, Stefan; Heal, Clare

    2016-01-01

    AIM To compare the outcomes of displaced distal radius fractures treated with volar locking plates and with immediate postoperative mobilisation with the outcomes of these fractures treated with modalities that necessitate 6 wk wrist immobilisation. METHODS A prospective, randomised controlled single-centre trial was conducted with 56 patients who had a displaced radius fracture were randomised to treatment either with a volar locking plate (n = 29), or another treatment modality (n = 27; cast immobilisation with or without wires or external fixator). Outcomes were measured at 12 wk. Functional outcome scores measured were the Patient-Rated Wrist Evaluation (PRWE) Score; Disabilities of the Arm, Shoulder and Hand and activities of daily living (ADLs). Clinical outcomes were wrist range of motion and grip strength. Radiographic parameters were volar inclination and ulnar variance. RESULTS Patients in the volar locking plate group had significantly better PRWE scores, ADL scores, grip strength and range of extension at three months compared with the control group. All radiological parameters were significantly better in the volar locking plate group at 3 mo. CONCLUSION The present study suggests that volar locking plates produced significantly better functional and clinical outcomes at 3 mo compared with other treatment modalities. Anatomical reduction was significantly more likely to be preserved in the plating group. Level of evidence: II. PMID:27795951

  11. 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

  12. Short-term and long-term site-specific effects of tennis playing on trabecular and cortical bone at the distal radius.

    PubMed

    Ducher, Gaële; Tournaire, Nicolas; Meddahi-Pellé, Anne; Benhamou, Claude-Laurent; Courteix, Daniel

    2006-01-01

    Mechanical loading during growth magnifies the normal increase in bone diameter occurring in long bone shafts, but the response to loading in long bone ends remains unclear. The aim of the study was to investigate the effects of tennis playing during growth at the distal radius, comparing the bone response at trabecular and cortical skeletal sites. The influence of training duration was examined by studying bone response in short-term (children) and long-term (young adults) perspectives. Bone area, bone mineral content (BMC), and bone mineral density (BMD) of the radius were measured by DXA in 28 young (11.6 +/- 1.4 years old) and 47 adult tennis players (22.3 +/- 2.7 years old), and 70 age-matched controls (12 children, 58 adults) at three sites: the ultradistal region (trabecular), the mid-distal region, and the third-distal region (cortical). At the ultradistal radius, young and adult tennis players displayed similar side-to-side differences, the asymmetry in BMC reaching 16.3% and 13.8%, respectively (P < 0.0001). At the mid- and third-distal radius, the asymmetry was much greater in adults than in children (P < 0.0001) for all the bone parameters (mid-distal radius, +6.6% versus +15.6%; third-distal radius, +6.9% versus +13.3%, for BMC). Epiphyseal bone enduring longitudinal growth showed a great capacity to respond to mechanical loading in children. Prolonging tennis playing into adulthood was associated with further increase in bone mineralization at diaphyseal skeletal sites. These findings illustrate the benefits of practicing impact-loading sports during growth and maintaining physical activity into adulthood to enhance bone mass accrual and prevent fractures later in life.

  13. Impaired bone microarchitecture at the distal radius in older men with low muscle mass and grip strength: the STRAMBO study.

    PubMed

    Szulc, Pawel; Blaizot, Stéphanie; Boutroy, Stephanie; Vilayphiou, Nicolas; Boonen, Steven; Chapurlat, Roland

    2013-01-01

    The aim was to study the association between bone microarchitecture and muscle mass and strength in older men. Volumetric bone mineral density (vBMD) and bone microarchitecture were assessed in 810 men aged ≥60 years at the distal radius by high-resolution peripheral computed tomography (HR-pQCT). Areal bone mineral density (aBMD) and appendicular muscle mass (ASM) were assessed by dual-energy X-ray absorptiometry (DXA). Relative ASM of the upper limbs (RASM-u.l.) was calculated as ASM of the upper limbs/(height)(2). Grip strength was measured by dynanometry. In multivariable models, men in the lowest RASM-u.l. quartile had lower cross-sectional area (CSA), cortical area (Ct.Ar), cortical thickness (Ct.Th), and trabecular area (Tb.Ar) at distal radius compared with men in the highest quartile. The trends remained significant after adjustment for grip strength. Men in the lowest quartile of the normalized grip strength (grip strength/[height](2)) had lower aBMD, total vBMD, Ct.Ar, Ct.Th, Tb.vBMD, and Tb.N, and higher Tb.Sp and Tb.Sp.SD. The associations for Ct.Ar, total vBMD, Ct.Th, Tb.vBMD, and Tb.Sp remained significant after adjustment for RASM-u.l. In the models including RASM-u.l. and normalized grip strength, CSA and Tb.Ar were associated with RASM-u.l. but not with the strength. Lower Ct.Th, Tb.vBMD, and Tb.N were associated with lower grip strength but not with RASM-u.l. Lower Ct.Ar was associated with lower grip strength and with lower RASM-u.l. In conclusion, in older men, low RASM-u.l. and low grip strength are associated with poor cortical and trabecular microarchitecture partly independently of each other, after adjustment for confounders. PMID:22865787

  14. Reliability Analysis of the Distal Radius and Ulna Classification for Assessing Skeletal Maturity for Patients with Adolescent Idiopathic Scoliosis

    PubMed Central

    Cheung, Jason Pui Yin; Samartzis, Dino; Cheung, Prudence Wing Hang; Cheung, Kenneth M. C.; Luk, Keith D. K.

    2015-01-01

    Study Design Prospective radiographic study. Objective To test the reliability of the Distal Radius and Ulna Classification (DRU). Methods This single-center study included prospectively recruited subjects with adolescent idiopathic scoliosis managed with bracing. The left-hand radiographs were measured using the DRU classification by two examiners. Intra- and interobserver reliability analysis were performed using intraclass correlation (ICC) analysis. Results From these clinics, 161 patients (124 females and 37 males) with left-hand radiographs were included in the study. The mean age was 13.3 years (standard deviation: 1.5). There was excellent intra- (ICC: 0.93 to 0.95) and interobserver (ICC: 0.97) reliability. Conclusions The DRU classification scheme has been shown to be accurate in determining the peak growth phase and growth cessation. It has now been confirmed to be a reliable tool. Future prospective studies should be performed to investigate its application in deciding when to apply bracing or operative treatment. PMID:26933618

  15. Oldest biliary endoprosthesis in situ

    PubMed Central

    Consolo, Pierluigi; Scalisi, Giuseppe; Crinò, Stefano F; Tortora, Andrea; Giacobbe, Giuseppa; Cintolo, Marcello; Familiari, Luigi; Pallio, Socrate

    2013-01-01

    The advantages of endoscopic retrograde cholangiopancreatography over open surgery have made it the predominant method of treating patients with choledocholithiasis. After sphincterotomy, however, 10%-15% of common bile duct stones cannot be removed with a basket or balloon. The methods for managing “irretrievable stones” include surgery, mechanical lithotripsy, intraductal or extracorporeal shock wave lithotripsy and biliary stenting. The case presented was a referred 82-year-old Caucasian woman with a 7-year-old plastic biliary endoprosthesis in situ. To the best of our knowledge the examined endoprosthesis is the oldest endoprosthesis in situ reported in the literature. Endoscopic biliary endoprosthesis placement remains a simple and safe procedure for patients with stones that are difficult to manage by conventional endoscopic methods and for patients who are unfit for surgery or who are high surgical risks. To date no consensus has been reached regarding how long a biliary prosthesis should remain in situ. Long-term biliary stenting may have a role in selected elderly patients if stones extraction has failed because the procedure may prevent stones impaction and cholangitis. PMID:23858381

  16. External fixation is more suitable for intra-articular fractures of the distal radius in elderly patients.

    PubMed

    Ma, Chuang; Deng, Qiang; Pu, Hongwei; Cheng, Xinchun; Kan, Yuhua; Yang, Jing; Yusufu, Aihemaitijiang; Cao, Li

    2016-01-01

    The purpose of this study was to compare the functional outcomes, psychological impact, and complication rates associated with external fixation and volar or dorsal plating in relation to the functional parameters following treatment of intra-articular fractures of the distal radius (IFDR) in patients older than 65 years. We hypothesized that using volar or dorsal plating would improve functional outcomes, but that it would be associated with more complications and equivalent functional outcomes when compared with the external fixation group. A total of 123 consecutive patients suffering from IFDR were recruited into the study. The patients were measured for clinical, radiological, and psychosocial functioning outcomes and were followed up after 1 week and 3, 6 and 12 months. After 3 months, the plating group had better pronation (P=0.001), supination, (P=0.047) and extension (P=0.043) scores. These differences were somewhat attenuated by 6 months and disappeared at 1 year. The plating group had a greater occurrence of wound infection (P=0.043), tendonitis, (P=0.024) and additional surgery compared with the external fixation group. The only TNO-AZL Adult Quality of Life scores in the plating group that were lower than those in the external fixation group were in the "gross motor" category (walking upstairs, bending over, walking 500 yards; P=0.023). Internal fixation was more advantageous than external fixation in the early rehabilitation period; after 1 year the outcomes were similar. The plating group showed significantly higher levels of wound infection and tendonitis and had a greater need for additional surgeries. PMID:27408765

  17. External fixation is more suitable for intra-articular fractures of the distal radius in elderly patients

    PubMed Central

    Ma, Chuang; Deng, Qiang; Pu, Hongwei; Cheng, Xinchun; Kan, Yuhua; Yang, Jing; Yusufu, Aihemaitijiang; Cao, Li

    2016-01-01

    The purpose of this study was to compare the functional outcomes, psychological impact, and complication rates associated with external fixation and volar or dorsal plating in relation to the functional parameters following treatment of intra-articular fractures of the distal radius (IFDR) in patients older than 65 years. We hypothesized that using volar or dorsal plating would improve functional outcomes, but that it would be associated with more complications and equivalent functional outcomes when compared with the external fixation group. A total of 123 consecutive patients suffering from IFDR were recruited into the study. The patients were measured for clinical, radiological, and psychosocial functioning outcomes and were followed up after 1 week and 3, 6 and 12 months. After 3 months, the plating group had better pronation (P=0.001), supination, (P=0.047) and extension (P=0.043) scores. These differences were somewhat attenuated by 6 months and disappeared at 1 year. The plating group had a greater occurrence of wound infection (P=0.043), tendonitis, (P=0.024) and additional surgery compared with the external fixation group. The only TNO-AZL Adult Quality of Life scores in the plating group that were lower than those in the external fixation group were in the “gross motor” category (walking upstairs, bending over, walking 500 yards; P=0.023). Internal fixation was more advantageous than external fixation in the early rehabilitation period; after 1 year the outcomes were similar. The plating group showed significantly higher levels of wound infection and tendonitis and had a greater need for additional surgeries. PMID:27408765

  18. Variation in the Incidence of Distal Radius Fractures in the US Elderly as Related to Slippery Weather Conditions

    PubMed Central

    Giladi, Aviram M.; Shauver, Melissa J.; Ho, Allison; Zhong, Lin; Kim, H. Myra; Chung, Kevin C.

    2014-01-01

    Background Distal radius fractures (DRFs) are costly and debilitating injuries, especially for the elderly. DRFs often occur from falls and more commonly occur outdoors. Inclement weather, especially in the winter, may increase the risk of fall-related injuries. Small community studies have reported increased risk of DRF due to inclement winter weather; however, larger studies are lacking. Methods We analyzed a sample of 2007 Medicare claims for DRF. Weather data were collected for the date and location of each DRF in our analysis cohort. A novel slipperiness score (0–7, 7 indicates the most slippery weather) was used as a measure of the severity of slippery outdoor conditions. Negative binomial regression models evaluated the correlation between slipperiness and DRF occurrence. Results Risk of DRF was higher in winter months (Incidence Rate Ratio=1.2, 95%CI 1.14–1.26, p<0.001). Days with average temperature ≤ 32°F (IRR=1.36, 95%CI 1.19–1.54, p<0.001), snow/ice on ground at the start of the day (IRR=1.45, 95%CI 1.25–1.68, p<0.001), and freezing rain (IRR=1.24, 95%CI 1.03–1.49, p=0.025) all had an increased risk of DRF. Risk of sustaining a DRF was increased 21% on days with a slipperiness score of 5 or above (IRR=1.21, 95%CI 1.08–1.20, p=0.007). Additionally, for each increase in slipperiness score above 4, the IRR of DRF increased as well. Conclusions Weather events that create slippery walking conditions, most often occurring in winter months, result in an increased risk of DRF in the US elderly. This finding can be used to support resource allocation as well as awareness and prevention campaigns. Level of Evidence IV; retrospective cohort PMID:24469166

  19. A NEW APPROACH TO PARTIALKNEE ENDOPROSTHESIS IN PRIMARY BONE SARCOMAS

    PubMed Central

    Penna, Valter; Toller, Eduardo Areas; Pinheiro, Carla; Becker, Ricardo Gehrke

    2015-01-01

    Partial knee endoprosthesis to bone sarcomas resections seems to be a good solution to treat this immature skeletal patients. The purpose of this study is to evaluate the functional score in fourteen patients, advantages and the technique indications. Methods: Retrospective analysis was done to assess in this group of patients the functional evolution and the possible complications of the procedure. 14 patients between 10 and 22 years functionally evaluated in Ennekin/ISOLS (International Society of Limb Salvage) criteria, being all of them operated in the same institution by the same surgeon. Were used distal femur and proximal tibia partial endoprosthesis. Results: General analysis demonstrated that the functional results were over than 67 percent (ISOLS criteria) in 78,6 percent of the patients, being considered excellent. 21,4 percent were considered good results, being between 50 and 66 percent. Bone storage was preserved when avoiding the adjacent segment resection. Surgery time was not prolonged in ligament reconstruction. Conclusion: Knee partial endoprosthesis are less damage to bone storage in young patients. The critics about the bad functional results are being supplied by new surgical techniques, excellent rehabilitation protocols, implants technology and the consequent learning curve. This option of treatment permits the preservation of healthy bone and provides the possibility of a revision replacement less aggressive. PMID:26998452

  20. Deterioration of trabecular plate-rod and cortical microarchitecture and reduced bone stiffness at distal radius and tibia in postmenopausal women with vertebral fractures.

    PubMed

    Wang, Ji; Stein, Emily M; Zhou, Bin; Nishiyama, Kyle K; Yu, Y Eric; Shane, Elizabeth; Guo, X Edward

    2016-07-01

    Postmenopausal women with vertebral fractures have abnormal bone microarchitecture at the distal radius and tibia by HR-pQCT, independent of areal BMD. However, whether trabecular plate and rod microarchitecture is altered in women with vertebral fractures is unknown. This study aims to characterize the abnormalities of trabecular plate and rod microarchitecture, cortex, and bone stiffness in postmenopausal women with vertebral fractures. HR-pQCT images of distal radius and tibia were acquired from 45 women with vertebral fractures and 45 control subjects without fractures. Trabecular and cortical compartments were separated by an automatic segmentation algorithm and subjected to individual trabecula segmentation (ITS) analysis for measuring trabecular plate and rod morphology and cortical bone evaluation for measuring cortical thickness and porosity, respectively. Whole bone and trabecular bone stiffness were estimated by finite element analysis. Fracture and control subjects did not differ according to age, race, body mass index, osteoporosis risk factors, or medication use. Women with vertebral fractures had thinner cortices, and larger trabecular area compared to the control group. By ITS analysis, fracture subjects had fewer trabecular plates, less axially aligned trabeculae and less trabecular connectivity at both the radius and the tibia. Fewer trabecular rods were observed at the radius. Whole bone stiffness and trabecular bone stiffness were 18% and 22% lower in women with vertebral fractures at the radius, and 19% and 16% lower at the tibia, compared with controls. The estimated failure load of the radius and tibia were also reduced in the fracture subjects by 13% and 14%, respectively. In summary, postmenopausal women with vertebral fractures had both trabecular and cortical microstructural deterioration at the peripheral skeleton, with a preferential loss of trabecular plates and cortical thinning. These microstructural deficits translated into lower

  1. The Anaform endoprosthesis: a proplast-coated femoral endoprosthesis.

    PubMed

    Keet, G G; Runne, W C

    1989-09-01

    The Anaform endoprosthesis study is a prospective trial by 12 orthopedic surgeons from six different hospitals in the Netherlands begun September 1984. As of March 1, 1988, 510 prostheses had been implanted, 60 with a follow up of more than 3 years. Of the 181 patients with a follow up of more than 2 years, 92% had a Harris hip score of more than 80 points. Apart from the main series, the prosthesis was used in 35 patients for revision of a cemented prosthesis, of whom 13 had a follow up of more than 2 years. Of these, ten patients (73%) had a Harris hip score of more than 80 points. Most patients studied were more than 65 years old. Fixation by ingrowth of fibrous tissue in a 2 mm thick, soft, flexible, low-modulus stem coating can provide painless function, clinical stabilization, and normal gait. The Anaform femoral endoprosthesis seems to be of advantage in the young patient as a method of cementless fixation. When necessary, removal without bone destruction is easy.

  2. Correlation between dorsovolar translation and rotation of the radius on the distal radioulnar joint during supination and pronation of forearm.

    PubMed

    Lee, Sang Ki; Song, Young Dong; Choy, Won Sik

    2015-09-01

    This study aimed to describe the patterns of movements about radius and ulna in individual degrees of forearm rotation. And, we also determined the effect of forearm rotation on translation and rotation of the radius with reference to the ulna, and to measure the relationship between forearm rotation, translation and rotation of the radius. Computed tomography of multiple, individual forearm positions, from 90° pronation to 90° supination, was conducted in 26 healthy volunteers (mean age, 43.9 years) to measure dorsovolar translation and rotation of the radius in the DRUJ in each forearm position. The mean dorsovolar translations were within 1.99 mm at 90° pronation to -2.03 mm at 90° supination. The rotations of the radius were 71.20° at 90° pronation and -46.63° at 90° supination. There were strong correlations between degrees of forearm rotation and dorsovolar translation (r=0.861, p<0.001) and rotation of the radius (r=0.960, p<0.001), suggesting that the DRUJ, carpal joints, and rotatory laxity of the carpal ligament, especially in supination, contribute to forearm supination and pronation. These findings provide an understanding of wrist kinematics, are may be useful in reconstructive wrist surgery to achieve normal range of motion, and are may be helpful for the design of DRUJ reconstruction using prostheses.

  3. The effect of static muscle forces on the fracture strength of the intact distal radius in vitro in response to simulated forward fall impacts.

    PubMed

    Reeves, Jacob M; Burkhart, Timothy A; Dunning, Cynthia E

    2014-08-22

    The distal radius fracture (DRF) is a particularly dominant injury of the wrist, commonly resulting from a forward fall on an outstretched hand. In an attempt to reduce the prevalence, costs, and potential long-term pain/deformities associated with this injury, in vivo and in vitro investigations have sought to classify the kinematics and kinetics of DRFs. In vivo forward fall work has identified a preparatory muscle contraction that occurs in the upper extremity prior to peak impact force. The present investigation constitutes the first attempt to systematically determine the effect of static muscle forces on the fracture threshold of the distal radius in vitro. Paired human cadaveric forearm specimens were divided into two groups, one that had no muscle forces applied (i.e., right arms) and the other that had muscle forces applied to ECU, ECRL, FCU and FCR (i.e., left arms), with magnitudes based on peak muscle forces and in vivo lower bound forward fall activation patterns. The specimens were secured in a custom-built pneumatic impact loading device and subjected to incremental impacts at pre-fracture (25 J) and fracture (150 J) levels. Similar fracture forces (6565 (866)N and 8665 (5133)N), impulses (47 (6)Ns and 57 (30)Ns), and energies (152 (38)J and 144 (45)J) were observed for both groups of specimens (p>0.05). Accordingly, it is suggested that, at the magnitudes presently simulated, muscle forces have little effect on the way the distal radius responds to forward fall initiated impact loading. PMID:24927979

  4. Comparison of palmar fixed-angle plate fixation with K-wire fixation of distal radius fractures (AO A2, A3, C1) in elderly patients.

    PubMed

    Goehre, F; Otto, W; Schwan, S; Mendel, T; Vergroesen, P P; Lindemann-Sperfeld, L

    2014-03-01

    The objective of this prospective, randomized, controlled trial was to compare the results of two operative techniques used for the treatment of unstable distal radius fractures in elderly patients classified as AO types A2, A3, and C1. Patients were treated with either fixed-angle volar plates or K-wires using a combined Kapandji and Willenegger technique. The functional results were determined after 3, 6, and 12 months. We included 40 patients aged over 65 years. Twenty-one patients were treated with plate fixation and 19 with K-wire fixation. The functional results, after 1 year, were nearly the same in both treatment groups, suggesting that either method is suitable for the treatment of unstable distal radius fractures of AO types A2, A3, and C1 in elderly patients. Sixteen of 21 patients with plate fixation and 17 of 19 patients with K-wire fixation present good results as assessed by the Castaing score. The median DASH score was three in both groups after 1 year. The patients with plate fixation were able to resume activities of daily living 4 weeks earlier. The most common complication was an intermediate post-traumatic median nerve irritation. Both methods are suitable for the treatment of elderly patients with unstable distal radius fractures of AO types A2, A3, and C1. If early functional post-operative care is important, palmar fixed-angle plate fixation is an ideal treatment approach. Otherwise, K-wire fixation is an effective, minimally invasive method with comparable clinical results.

  5. A rare combined injury of dorsal fracture-dislocation of four carpometacarpal joints and trapezium, trapezoid and distal radius bone fractures.

    PubMed

    Touloupakis, Georgios; Stuflesser, Wilfried; Antonini, Guido; Ferrara, Fabrizio; Crippa, Cornelio; Lettera, Maria Gabriella

    2016-05-06

    Incorrect or delayed diagnosis and treatment of the carpometacarpal fracture-dislocations is often associated with poor prognosis. We present a rare case of unusual pattern of injury, involving dorsal dislocation of four ulnar carpometacarpal joints, associated with fracture of the trapezium, a burst fracture of the trapezoid  bone and an extra-articular fracture of the third distal  of the radius. The first surgical intervention was followed by unsatisfactory results, confirmed by the CT scans. A second surgery followed and an open reduction and pinning with K wires performed. Post-operative follow up lasting for nine months revealed a very good surgical outcome.

  6. Can Total Wrist Arthroplasty Be an Option for Treatment of Highly Comminuted Distal Radius Fracture in Selected Patients? Preliminary Experience with Two Cases

    PubMed Central

    Schmidt, Ingo

    2015-01-01

    We present two case reports of successful primary shortening of the forearm and total wrist arthroplasty (TWA) using the new angle-stable Maestro Wrist Reconstructive System (WRS) for treatment of highly comminuted distal radius fracture in selected autonomous patients. In a 56-year-old male patient with adequate bone stock, insertion of the noncemented Maestro WRS was combined with ulnar shortening osteotomy. In an 84-year-old female patient with poor osteoporotic bone stock, insertion of the radial cemented Maestro WRS was combined with ulnar head resection. Both patients could resume their work without additional surgery after TWA. At the 1-year follow-up, there were no changes in position of either implant without signs of loosening, no impingement, and no instability of the distal radioulnar joint or the distal ulna stump. All clinical parameters (DASH score, pain through VAS, and grip strength) were satisfactory. Both patients reported that they would have the same procedure again. Further experience is needed to validate this concept. PMID:26491587

  7. Intra-articular Fractures of the Sigmoid Notch of the Distal Radius: Analysis of Progression to Distal Radial Ulnar Joint Arthritis and Impact on Upper Extremity Function in Surgically Treated Fractures.

    PubMed

    Vitale, Mark A; Brogan, David M; Shin, Alexander Y; Berger, Richard A

    2016-03-01

    Background Studies have established an increased risk of radiocarpal joint posttraumatic arthritis in patients with displaced intra-articular fractures of the distal radius, although this phenomenon has yet to be evaluated in the distal radioulnar joint (DRUJ). Purpose We hypothesized that patients with displaced intra-articular fractures of the sigmoid notch would have a higher prevalence of DRUJ arthritis and greater upper extremity dysfunction after operative treatment of distal radius fractures compared with fractures without sigmoid notch involvement. We also hypothesized that the degree of sigmoid notch incongruity would be correlated with the grade of DRUJ arthritis and the severity of upper extremity dysfunction. Patients and Methods A retrospective review was conducted on surgically treated patients with distal radius fractures with pre- and/or postoperative computed tomography (CT) scans. Patients were divided into groups based on presence or absence of fracture extension into the sigmoid notch. Within the sigmoid notch group, postoperative CT scans were used to measure sigmoid notch fracture step-off and diastasis (mm), as well as volar or dorsal DRUJ subluxation (%). Patients were administered Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaires and radiographs were obtained to grade DRUJ arthritis using the Kellgren-Lawrence (KL) radiographic criteria. Results Thirty-three patients were included (19 with sigmoid notch involvement and 14 without) with an average radiographic follow-up of 6.3 years (range: 3.5-10.1 years). DASH scores were available for all patients, and radiographic follow-up was available in 24 patients (73%). A trend toward higher grade of DRUJ arthritis and poorer average DASH was found in those with sigmoid notch involvement, but was not statistically different. In the sigmoid notch group there were poorer DASH scores in patients with coronal step-off > 1.0-mm (p < 0.05). There were no significant

  8. A trans-ethnic genome-wide association study identifies gender-specific loci influencing pediatric aBMD and BMC at the distal radius

    PubMed Central

    Chesi, Alessandra; Mitchell, Jonathan A.; Kalkwarf, Heidi J.; Bradfield, Jonathan P.; Lappe, Joan M.; McCormack, Shana E.; Gilsanz, Vicente; Oberfield, Sharon E.; Hakonarson, Hakon; Shepherd, John A.; Kelly, Andrea; Zemel, Babette S.; Grant, Struan F.A.

    2015-01-01

    Childhood fractures are common, with the forearm being the most common site. Genome-wide association studies (GWAS) have identified more than 60 loci associated with bone mineral density (BMD) in adults but less is known about genetic influences specific to bone in childhood. To identify novel genetic factors that influence pediatric bone strength at a common site for childhood fractures, we performed a sex-stratified trans-ethnic genome-wide association study of areal BMD (aBMD) and bone mineral content (BMC) Z-scores measured by dual energy X-ray absorptiometry at the one-third distal radius, in a cohort of 1399 children without clinical abnormalities in bone health. We tested signals with P < 5 × 10−6 for replication in an independent, same-age cohort of 486 Caucasian children. Two loci yielded a genome-wide significant combined P-value: rs7797976 within CPED1 in females [P = 2.4 × 10−11, β =− 0.30 standard deviations (SD) per T allele; aBMD-Z] and rs7035284 at 9p21.3 in males (P = 1.2 × 10−8, β = 0.28 SD per G allele; BMC-Z). Signals at the CPED1-WNT16-FAM3C locus have been previously associated with BMD at other skeletal sites in adults and children. Our result at the distal radius underscores the importance of this locus at multiple skeletal sites. The 9p21.3 locus is within a gene desert, with the nearest gene flanking each side being MIR31HG and MTAP, neither of which has been implicated in BMD or BMC previously. These findings suggest that genetic determinants of childhood bone accretion at the radius, a skeletal site that is primarily cortical bone, exist and also differ by sex. PMID:26041818

  9. Tuberculosis of Distal Radius Presenting as Cystic Lesion in a Nine-Month-Old Infant: A Rare Case Report

    PubMed Central

    Garg, Anant Kumar; Bandyopadhyay, Abhishek; Kumar, Sanjay; Pal, Sumanta

    2016-01-01

    Tuberculous osteomyelitis affecting long bones is a rare form of tuberculosis. Among infants born in endemic region, often it is difficult to diagnose owing to its subtle clinical features. Here, a case of tuberculous osteomyelitis affecting the distal radial metaphysis is reported, presenting as a cystic lesion in a nine-month-old male infant. Open biopsy with curettage was performed followed by filling of the cavity with synthetic bone substitute (beta tricalcium phosphate granules). The diagnosis was confirmed by histopathological examination and demonstration of acid fast bacilli. Further treatment with anti-tubercular drugs led to clinical and radiological improvement. This case report highlights the importance of keeping tuberculosis as a differential diagnosis while dealing with cases with similar presentation in an endemic region. PMID:27790537

  10. Desmoplastic fibroma of the distal radius: an interesting case and a review of the literature and therapeutic implications

    PubMed Central

    Beebe, Kathleen S.; Ippolito, Joseph A.

    2016-01-01

    Desmoplastic fibromas are rare, benign, locally aggressive bone tumors, which arise primarily in patients younger than 30 years old. Historically, even with greater functional loss, en bloc or wide resection of the tumors to prevent local recurrence has been the method of choice in treatment. This article discusses the presentation of a 10-year-old male who presented with a mass in the distal forearm, after reporting difficulty in pronation and supination. The patient was ultimately treated with wide resection and allo-arthrodesis with allograft. Post-operatively, the patient has exhibited excellent recovery, including normal range of motion at the shoulder and elbow, and ability to perform all activities of daily livings despite reduced grip strength compared with the contralateral side. PMID:26767767

  11. Desmoplastic fibroma of the distal radius: an interesting case and a review of the literature and therapeutic implications.

    PubMed

    Beebe, Kathleen S; Ippolito, Joseph A

    2016-01-13

    Desmoplastic fibromas are rare, benign, locally aggressive bone tumors, which arise primarily in patients younger than 30 years old. Historically, even with greater functional loss, en bloc or wide resection of the tumors to prevent local recurrence has been the method of choice in treatment. This article discusses the presentation of a 10-year-old male who presented with a mass in the distal forearm, after reporting difficulty in pronation and supination. The patient was ultimately treated with wide resection and allo-arthrodesis with allograft. Post-operatively, the patient has exhibited excellent recovery, including normal range of motion at the shoulder and elbow, and ability to perform all activities of daily livings despite reduced grip strength compared with the contralateral side.

  12. Intra-articular fractures of the distal radius: bridging external fixation in slight flexion and ulnar deviation along articular surface instead of radial shaft.

    PubMed

    Moradi, Ali; Ebrahimzadeh, Mohammad H; Jupiter, Jess B

    2014-03-01

    Forty-one patients with intra-articular fracture of the distal radius (AO Type C) were treated with a double joint-bridging external fixator placed radial side of the fracture site and the wrist placed in slight flexion and ulnar deviation equal to the palmar tilt and radial inclination of the uninjured wrist. The patients were evaluated according to the system of Gartland and Werley an average of 43 months (range, 34 to 53 mo) after surgery. There were 14 excellent, 18 good, 7 fair, and 2 poor results. The average flexion was 94% of the normal side, extension 91%, pronation 95%, and supination 84%. The average radial inclination was 22 ± 10 degrees, palmar tilt 8 ± 14 degrees, and maximum articular step or gap was 2 mm. Bridging external fixation with slight wrist flexion and ulnar deviation equal to preinjured palmar tilt and radial inclination provides acceptable clinical and radiologic results.

  13. Predicting surface strains at the human distal radius during an in vivo loading task--finite element model validation and application.

    PubMed

    Bhatia, Varun A; Edwards, W Brent; Troy, Karen L

    2014-08-22

    Bone strains resulting from physical activity are thought to be a primary driver of bone adaptation, but cannot be directly noninvasively measured. Because bone adapts nonuniformly, physical activity may make an important independent structural contribution to bone strength that is independent of bone mass and density. Our objective was to create and validate methods for subject-specific finite element (FE) model generation that would accurately predict the surface strains experienced by the distal radius during an in vivo loading task, and to apply these methods to a group of 23 women aged 23-35 to examine variations in strain, bone mass and density, and physical activity. Four cadaveric specimens were experimentally tested and specimen-specific FE models were developed to accurately predict periosteal surface strains (root mean square error=16.3%). In the living subjects, when 300 N load was simulated, mean strains were significantly inversely correlated with BMC (r=-0.893), BMD (r=-0.892) and physical activity level (r=-0.470). Although the group of subjects was relatively homogenous, BMD varied by two-fold (range: 0.19-0.40 g/cm(3)) and mean energy-equivalent strain varied by almost six-fold (range: 226.79-1328.41 με) with a simulated 300 N load. In summary, we have validated methods for estimating surface strains in the distal radius that occur while leaning onto the palm of the hand. In our subjects, strain varied widely across individuals, and was inversely related to bone parameters that can be measured using clinical CT, and inversely related to physical activity history. PMID:24882740

  14. Deficits in distal radius bone strength, density and microstructure are associated with forearm fractures in girls: an HR-pQCTstudy

    PubMed Central

    Määttä, M.; Macdonald, H. M.; Mulpuri, K.

    2016-01-01

    Summary Forearm fractures are common during growth. We studied bone strength in youth with a recent forearm fracture. In girls, suboptimal bone strength was associated with fractures. In boys, poor balance and physical inactivity may lead to fractures. Prospective studies will confirm these relationships and identify targets for prevention strategies. Introduction The etiology of pediatric forearm fractures is unclear. Thus, we examined distal radius bone strength, microstructure, and density in children and adolescents with a recent low- or moderate-energy forearm fracture and those without forearm fractures. Methods We assessed the non-dominant (controls) and non-fractured (cases) distal radius (7 % site) using high-resolution peripheral quantitative computed tomography (HR-pQCT) (Scanco Medical AG) in 270 participants (girls: cases n=47, controls n=61 and boys: cases n=88, controls n=74) aged 8–16 years. We assessed standard anthropometry, maturity, body composition (dual energy X-ray absorptiometry (DXA), Hologic QDR 4500 W) physical activity, and balance. We fit sex-specific logistic regression models for each bone outcome adjusting for maturity, ethnicity, height, and percent body fat. Results In girls, impaired bone strength (failure load, ultimate stress) and a high load-to-strength ratio were associated with low-energy fractures (odds ratios (OR) 2.8–4.3). Low total bone mineral density (Tt.BMD), bone volume ratio, trabecular thickness, and cortical BMD and thickness were also associated with low-energy fractures (ORs 2.0–7.0). In boys, low Tt.BMD, but not bone strength, was associated with low-energy fractures (OR=1.8). Boys with low-energy fractures had poor balance and higher percent body fat compared with controls (p<0.05). Boys with fractures (both types) were less active than controls (p<0.05). Conclusions Forearm fracture etiology appears to be sex-specific. In girls, deficits in bone strength are associated with fractures. In boys, a

  15. Distal Radius Fracture (Broken Wrist)

    MedlinePlus

    ... choice depends on many factors, such as the nature of the fracture, your age and activity level, ... causing the cast to loosen. Depending on the nature of the fracture, your doctor may closely monitor ...

  16. Treatment of reducible unstable fractures of the distal radius in adults: a randomised controlled trial of De Palma percutaneous pinning versus bridging external fixation

    PubMed Central

    2010-01-01

    Background At present, there is no conclusive evidence regarding the best treatment method for reducible unstable fractures of the distal radius. This study compared the effectiveness of two methods used in surgical treatment of such fractures: percutaneous pinning and external fixation. Methods We randomly allocated 100 patients into two groups treated surgically with modified De Palma percutaneous pinning and bridging external fixation. Independent but not blinded evaluators administered the DASH quality-of-life questionnaire at postoperative months 6 and 24, performed functional assessment of pain, range of motion, and palm grip strength, and radiographic examinations (volar and radial angle, and height of the radius) before the operation, immediately afterwards, and at 6 and 24 months postoperative. Modified De Palma percutaneous pinning patients used an above-elbow cast whereas external fixation group had unrestricted elbow motion after surgery. Patients who for any reason demonstrated treatment failure or required additional interventions were followed up and their results were included in the group into which these patients had initially been randomised according to the intention-to-treat principle. A significance level of 5% (alpha = 0.05). was used for all statistical tests, such that tests presenting a p-value less than 0.05 were considered statistically significant. Results Ninety one (58.8 mean age and 66 participants were female) were included in the final assessment at 24 months. The DASH questionnaire evaluation showed a statistically significant result favouring the De Palma group (mean difference = -7.1 p = 0.044) after six months, but this was not maintained at 24 months. There were no statistically differences between the groups with respect to palm grip strength. Analysis of the range-of-motion limitation index (uninjured side minus affected side motion of) showed a statistical difference (mean difference = 2.4 p = 0.043) favoring the external

  17. The influence of bone density and anisotropy in finite element models of distal radius fracture osteosynthesis: Evaluations and comparison to experiments.

    PubMed

    Synek, A; Chevalier, Y; Baumbach, S F; Pahr, D H

    2015-11-26

    Continuum-level finite element (FE) models can be used to analyze and improve osteosynthesis procedures for distal radius fractures (DRF) from a biomechanical point of view. However, previous models oversimplified the bone material and lacked thorough experimental validation. The goal of this study was to assess the influence of local bone density and anisotropy in FE models of DRF osteosynthesis for predictions of axial stiffness, implant plate stresses, and screw loads. Experiments and FE analysis were conducted in 25 fresh frozen cadaveric radii with DRFs treated by volar locking plate osteosynthesis. Specimen specific geometries were captured using clinical quantitative CT (QCT) scans of the prepared samples. Local bone material properties were computed based on high resolution CT (HR-pQCT) scans of the intact radii. The axial stiffness and individual screw loads were evaluated in FE models, with (1) orthotropic inhomogeneous (OrthoInhom), (2) isotropic inhomogeneous (IsoInhom), and (3) isotropic homogeneous (IsoHom) bone material and compared to the experimental axial stiffness and screw-plate interface failures. FE simulated and experimental axial stiffness correlated significantly (p<0.0001) for all three model types. The coefficient of determination was similar for OrthoInhom (R(2)=0.807) and IsoInhom (R(2)=0.816) models but considerably lower for IsoHom models (R(2)=0.500). The peak screw loads were in qualitative agreement with experimental screw-plate interface failure. Individual loads and implant plate stresses of IsoHom models differed significantly (p<0.05) from OrthoInhom and IsoInhom models. In conclusion, including local bone density in FE models of DRF osteosynthesis is essential whereas local bone anisotropy hardly effects the models׳ predictive abilities.

  18. Reference values for digital X-ray radiogrammetry parameters in children and adolescents in comparison to estimates in patients with distal radius fractures.

    PubMed

    Renz, Diane M; Malich, Ansgar; Ulrich, Andreas; Pfeil, Alexander; Mentzel, Hans-Joachim; Streitparth, Florian; Maurer, Martin H; Teichgräber, Ulf K; Böttcher, Joachim

    2016-01-01

    The first objective of this study was to determine normative digital X-ray radiogrammetry (DXR) values, based on original digital images, in a pediatric population (aged 6-18 years). The second aim was to compare these reference data with patients suffering from distal radius fractures, whereas both cohorts originated from the same geographical region and were evaluated using the same technical parameters as well as inclusion and exclusion criteria. DXR-BMD and DXR-MCI of the metacarpal bones II-IV were assessed on standardized digital hand radiographs, without printing or scanning procedures. DXR parameters were estimated separately by gender and among six age groups; values in the fracture group were compared to age- and gender-matched normative data using Student's t tests and Z scores. In the reference cohort (150 boys, 138 girls), gender differences were found in bone mineral density (DXR-BMD), with higher values for girls from 11 to 14 years and for boys from 15 to 18 years (p < 0.05). Girls had higher normative metacarpal index (DXR-MCI) values than boys, with significant differences at 11-14 years (p < 0.05). In the case-control investigation, the fracture group (95 boys, 69 girls) presented lower DXR-BMD at 15-18 years in boys and 13-16 years in girls vs. the reference cohort (p < 0.05); DXR-MCI was lower at 11-18 years in boys and 11-16 years in girls (p < 0.05). Mean Z scores in the fracture group for DXR-BMD were -0.42 (boys) and -0.46 (girls), and for DXR-MCI were -0.51 (boys) and -0.53 (girls). These findings indicate that the fully digital DXR technique can be accurately applied in pediatric populations ≥ 6 years of age. The lower DXR-BMD and DXR-MCI values in the fracture group suggest promising early identification of individuals with increased fracture risk, without the need for additional radiation exposure, enabling the initiation of prevention strategies to possibly reduce the incidence of osteoporosis later in life.

  19. Treatment of unstable distal radius fractures: non-invasive dynamic external fixator versus volar locking plate – functional and radiological outcome in a prospective case-controlled series

    PubMed Central

    Bajwa, Ali S.; Rammappa, Manju; Lee, Ling; Nanda, Rajesh

    2015-01-01

    Introduction: Distal radius fracture (DRF) is a common injury and various treatment modalities including open reduction and internal fixation (ORIF) with volar locking plate are available. More recently, a non-invasive external fixator has been used. Aims: To prospectively compare the use of a non-invasive external fixator with early dynamisation for DRF against ORIF with volar locking plate control group. Methods: Consecutive patients with closed DRF were included in a prospective case-controlled study. Patients were assigned to non-invasive external fixator or ORIF. Minimum follow-up was two years. Follow-up was at weeks 2, 4, 6, 8, 12, 26 and at one and two-year post-operatively. The outcome measures included demographic details, injury mechanism, AO fracture type, risk factors, body mass index (BMI), ulnar styloid fracture and dorsal comminution, radiographs, grip strength and DASH score. Results: Consecutive 50 patients were treated either with non-invasive external fixator (25/50) or with ORIF (25/50) and the mean age of the two groups was 53 years (SD 17.1) and 49 years (SD 19.5), respectively. Demographics were matched in two groups. In the non-invasive external fixator group, there were 10 AO Type-A, 5 Type-B and 10 Type-C fractures. The ORIF group included 8 Type-A, 6 Type-B and 11 Type-C fractures. The mean DASH score at three-months and one-year post-injury in non-invasive fixator group was 12.2 (SD 3.1) and 3.5 (SD 0.7), respectively, significantly greater than those of ORIF group 14.5 (SD 5.6) and 11.2 (SD 4.4), respectively (p < 0.05). Conclusion: DRF treated with non-invasive external fixator can give functional results superior to ORIF at three-months and the trend is maintained at one and two-year post-operatively. PMID:27163089

  20. Sensitivity to metals in 40 patients with failed hip endoprosthesis.

    PubMed

    Milavec-Puretić, V; Orlić, D; Marusić, A

    1998-01-01

    Hypersensitivity to metals and tissue reaction around a failed implant were investigated in 40 patients undergoing revision hip arthroplasty. Metal sensitivity was tested using a standard cutaneous patch test. Nine patients were positive for chromium, nickel, cobalt, metal rust or endoprosthesis scrapings, or combinations of these allergens. Patients with positive or negative patch test did not differ in terms of their age, sex, primary diagnosis, number of endoprosthesis revisions, length of implant function, presence of other metal parts around the implant, circulating immunocomplexes, and histological appearance of the tissue around the implant. We conclude that stainless steel endoprostheses may be safely used for repeated revision hip arthroplasty, and that hypersensitivity to metals probably does not play a significant role in the loosening of the endoprosthesis.

  1. A Two Phase Treatment of an Infected Hip Endoprosthesis.

    PubMed

    Ciriviri, Jasmin; Talevski, Darko; Nestorovski, Zoran; Vraniskoski, Tode; Mishevska-Perchinkova, Snežana

    2015-01-01

    The revision of the two phase treatment represents a golden standard in the treatment of infected endoprosthesis. Throughout this study, the results of 21 patients with an infected hip endoprosthesis treated in two phases have been processed, with the use of an antibiotic spacer, within the period of 2009 and 2012. Thereby, a unique protocol for diagnosis and treatment of infections has been applied to all the patients, which entails a preoperational x-ray image, laboratory findings (Se, CRP), as well as a puncture aspiration with a microbiological and biochemical examination of the aspirated fragments. The operational treatment consists of: taking a sample for microbiological and histopathological diagnosis, removal of the implanted endoprosthesis, excision of the avascular and necrotic tissue and installing an antibiotic spacer. Postoperatively, the patients are treated with a parenteral application of an antibiotics based on an antibiogram, throughout a period of two weeks, and later on an oral treatment, a combination of two antibiotics, depending on the antibiogram, within the following four to six weeks. After the appeasement of the local findings and the laboratory results, a revision with a removal of the antibiotic spacer and reimplantation of an endoprosthesis - revisional or primary has been conducted on the patients, depending on the bone deficit. The functionality of the joint is graded based on the Haris Hip Score. The patients are being observed postoperatively for a period of 12 to 36 months. A definite reimplantation has been applied to 20 patients, while one patient has been treated with a resection method. The Haris Hip Score was 45 preoperatively, and 80 postoperatively. The applied protocol of the treatment of infected endoprosthesis is effective in the eradication of the infection and the final reimplantation. PMID:27442385

  2. [Do injuries of the upper extremity in geriatric patients end up in helplessness? A prospective study for the outcome of distal radius and proximal humerus fractures in individuals over 65].

    PubMed

    Einsiedel, T; Becker, C; Stengel, D; Schmelz, A; Kramer, M; Däxle, M; Lechner, F; Kinzl, L; Gebhard, F

    2006-12-01

    In a prospective study 104 patients >or=65 years with distal radius fractures (DRF; n=52) and proximal forearm fractures (PHF; n=52) were followed up for a period of 4 months after injury. As an inception- cohort study, influence on treatment pattern was not part of the examination. A total of 53% of the DRF and 74% of the PHF patients underwent surgery. There were no significant changes in the ability of daily living management (IADL) with either fracture form. Functional outcome was better in PHF than DRF patients. PHF patients showed a high incidence in "fear of falling" throughout the whole study, whereas fear of falling rose significantly in DRF patients. 4% of DRF and 9.6% of PHF patients died during the observation period, while 6% of DRF and even 17% of PHF patients had to give up their own housekeeping. One third of both patient groups did not receive physiotherapy. In only 12% of DRF and 6% of PHF patients was osteoporosis treated. In both groups of patients there was a significant worsening in the ability of walking after injury, leading to two or more new falls in 24% of DRF and 28% of PHF patients.

  3. Functional outcomes and cost estimation for extra-articular and simple intra-articular distal radius fractures treated with open reduction and internal fixation versus closed reduction and percutaneous Kirschner wire fixation

    PubMed Central

    Dzaja, Ivan; MacDermid, Joy C.; Roth, James; Grewal, Ruby

    2013-01-01

    Background We sought to compare direct costs and clinical and radiographic outcomes for distal radius fractures (DRF) treated with open reduction internal fixation with volar locking plates (VLP) versus closed reduction and percutaneous pinning (CRPP). Methods We identified patients with AO-type A and C1 DRFs from a prospective database. Outcomes were assessed at 6 weeks and at 3, 6 and 12 months, and surgical care costs were estimated. Results Twenty patients were treated with CRPP and 24 with VLP. There were no significant differences in patient-rated wrist evaluation (PRWE) scores between the 2 groups at any time point (mean 16.2 ± 23.1 in the CRPP group v. 21.5 ± 23.6 in the VLP group, p = 0.91). Overall alignment was maintained in both groups; however, there was a greater loss of radial height over time with CRPP than VLP (0.97 mm v. 0.25 mm, p = 0.018). The mean duration of surgery was longer for VLP than CRPP (113.9 ± 39.5 min v. 86.5 ± 7.8 min, p = 0.029), but there were fewer clinic visits (5.2 ± 1.4 v. 7.8 ± 1.3, p < 0.001) and fewer radiographs (7.4 ± 2.7 v. 9 ± 2.4, p = 0.031). The total cost per case was greater for VLP than CRPP ($1637.27 v. $733.91). Conclusion Based on PRWE scores, VLPs did not offer any significant advantage over CRPP in patients with simple fracture types between 3 and 12 months, but they were much more costly. Whether VLP offers any functional advantage earlier in recovery, thereby justifying their expense, requires further investigation in the form of a prospective randomized trial with a detailed cost analysis. PMID:24284144

  4. Non-linear three-dimensional finite element analysis of a cementless hip endoprosthesis.

    PubMed

    Tensi, H M; Gese, H; Ascherl, R

    1989-01-01

    In this finite element study the stresses between a stem component of a cementless hip endoprosthesis (Young modulus of Co-Cr-Mo) and the human femur were calculated for two different loading types. Linear and non-linear models were used to simulate the interface implant bone. Two models, a stem with a porous coated surface over the entire length and a stem with a porous coated surface in the proximal region were compared regarding the load transmission to the femur. An additional calculation of an 'isoelastic' stem (Young modulus of cortical bone) was done to show the influence of the stem stiffness. A porous coated surface over the entire length causes principal shear stresses up to 2.75 MPa in the distal-medial region during level walking. The highest compressive stresses were calculated in the proximal-lateral region as 1.5 MPa in cancellous bone. A more physiological load transmission is obtained by limiting the coated area to the proximal region. All stresses in the two models are lower than experimentally evaluated strengths in the interface between implant and bone. A strong influence of the Young modulus of the stem material on the interface stresses was found. An 'isoelastic' stem causes compressive stresses in the proximal-lateral region whose values exceed the experimental strength of cancellous bone.

  5. Use of MR-based trabecular bone microstructure analysis at the distal radius for osteoporosis diagnostics: a study in post-menopausal women with breast cancer and treated with aromatase inhibitor

    PubMed Central

    Baum, Thomas; Karampinos, Dimitrios C.; Seifert-Klauss, Vanadin; Pencheva, Tsvetelina D.; Jungmann, Pia M.; Rummeny, Ernst J.; Müller, Dirk; Bauer, Jan S.

    2016-01-01

    Summary Purpose Treatment with aromatase inhibitor (AI) is recommended for post-menopausal women with hormone-receptor positive breast cancer. However, AI therapy is known to induce bone loss leading to osteoporosis with an increased risk for fragility fractures. The purpose of this study was to investigate whether changes of magnetic resonance (MR)-based trabecular bone microstructure parameters as advanced imaging biomarker can already be detected in subjects with AI intake but still without evidence for osteoporosis according to dual energy X-ray absorptiometry (DXA)-based bone mineral density (BMD) measurements as current clinical gold standard. Methods Twenty-one postmenopausal women (62±6 years of age) with hormone-receptor positive breast cancer, ongoing treatment with aromatase inhibitor for 23±15 months, and no evidence for osteoporosis (current DXA T-score greater than −2.5) were recruited for this study. Eight young, healthy women (24±2 years of age) were included as controls. All subjects underwent 3 Tesla magnetic resonance imaging (MRI) of the distal radius to assess the trabecular bone microstructure. Results Trabecular bone microstructure parameters were not significantly (p>0.05) different between subjects with AI intake and controls, including apparent bone fraction (0.42±0.03 vs. 0.42±0.05), trabecular number (1.95±0.10 mm−1 vs 1.89±0.15 mm−1), trabecular separation (0.30±0.03 mm vs 0.31±0.06 mm), trabecular thickness (0.21±0.01 mm vs 0.22±0.02 mm), and fractal dimension (1.70±0.02 vs. 1.70±0.03). Conclusion These findings suggest that the initial deterioration of trabecular bone microstructure as measured by MRI and BMD loss as measured by DXA occur not sequentially but rather simultaneously. Thus, the use of MR-based trabecular bone microstructure assessment is limited as early diagnostic biomarker in this clinical setting. PMID:27252740

  6. Performance of the MRI-Based Virtual Bone Biopsy in the Distal Radius: Serial Reproducibility and Reliability of Structural and Mechanical Parameters in Women Representative of Osteoporosis Study Populations

    PubMed Central

    Lam, Shing Chun Benny; Wald, Michael J.; Rajapakse, Chamith S.; Liu, Yinxiao; Saha, Punam K.; Wehrli, Felix W.

    2011-01-01

    Serial reproducibility and reliability critically determine sensitivity to detect changes in response to intervention and provide a basis for sample size estimates. Here, we evaluated the performance of the MRI-based Virtual Bone Biopsy in terms of 26 structural and mechanical parameters in the distal radius of 20 women in the age range of 50 to 75 years (mean = 62.0 years, S.D. = 8.1 years), representative of typical study populations in drug intervention trials and fracture studies. Subjects were examined three times at average intervals of 20.2 days (S.D. = 14.5 days) by MRI at 1.5 T field strength at a voxel size of 137×137×410 μm3. Methods involved prospective and retrospective 3D image registration and auto-focus motion correction. Analyses were performed from a central 5×5×5 mm3 cuboid subvolume and trabecular volume consisting of a 13 mm axial slab encompassing the entire medullary cavity. Whole-volume axial stiffness and sub-regional Young’s and shear moduli were computed by finite-element analysis. Whole-volume-derived aggregate mean coefficient of variation of all structural parameters was 4.4% (range 1.8% to 7.7%) and 4.0% for axial stiffness; corresponding data in the subvolume were 6.5% (range 1.6% to 13.0%) for structural, and 5.5% (range 4.6% to 6.5%) for mechanical parameters. Aggregate ICC was 0.976 (range 0.947 to 0.986) and 0.992 for whole-volume-derived structural parameters and axial stiffness, and 0.946 (range 0.752 to 0.991) and 0.974 (range 0.965 to 0.978) for subvolume-derived structural and mechanical parameters, respectively. The strongest predictors of whole-volume axial stiffness were BV/TV, junction density, skeleton density and Tb.N (R2 0.79 – 0.87). The same parameters were also highly predictive of sub-regional axial modulus (R2 0.88 – 0.91). The data suggest that the method is suited for longitudinal assessment of the response to therapy. The underlying technology is portable and should be compatible with all general

  7. [Knee endoprosthesis: sports orthopedics possibilities and limitations].

    PubMed

    Kuster, M S; Grob, K; Gächter, A

    2000-08-01

    Many patients would like to resume some sport activities after total knee replacement; however, most recommendations are based on subjective opinion rather than scientific evidence. The following paper presents a literature review of sports after total knee replacement and includes recommendations which are based on biomechanical laws. Most total knee designs show increased conformity near full extension. Beyond a certain knee flexion angle, the conformity ratio decreases due to a reduced femoral radius. Therefore, these designs accept higher loads near full extension than in flexion. In order to recommend suitable physical activities after total knee replacement, both the load and the knee flexion angle of the peak load must be considered. It has been shown that power walking and cycling produce the lowest polyethylene inlay stress of a total knee replacement and seem to be the least demanding endurance activities. Jogging and downhill walking show high inlay stress levels and should be avoided. Hence, for mountain hiking, patients are advised to avoid descents or at least use skipoles and walk slowly downhill to reduce the load on the knee joint. It must also be mentioned that any activity represents additional wear, which may affect the long-term results of total knee replacements. Further clinical studies are necessary to validate the biomechanical investigations. PMID:11013918

  8. Computer-aided resection and endoprosthesis design for the management of malignant bone tumors around the knee: outcomes of 12 cases

    PubMed Central

    2013-01-01

    Background To report the outcomes of computer-aided resection and endoprosthesis design for the management of malignant bone tumors around the knee. Methods Computed tomography (CT) and magnetic resonance imaging (MRI) data were input into computer software to produce three-dimensional (3D) models of the tumor extent. Imaging data was then used to create a template for surgical resection, and development of an individualized combined allogeneic bone/endoprosthesis. Surgical simulations were performed prior to the actual surgery. Results This study included 9 males and 3 females with a mean age of 25.3 years (range, 13 to 40 years). There were 9 tumors in the distal femur and 3 in the proximal tibia. There were no surgical complications. In all cases pathologically confirmed clear surgical margins were obtained. Postoperative radiographs showed the range of tumor resection was in accordance with the preoperative design, and the morphological reconstruction of the bone defect was satisfactory with complete bilateral symmetry. The mean follow-up time was 26.5 months. Two patients died of their disease and the remaining are alive and well without evidence of recurrence. All patients are able to ambulate freely without restrictions. At the last follow-up, the average International Society of Limb Salvage score was 25.8 (range, 18 to 27), and was excellent in 8 cases and good in 4 cases. Conclusions Computer-aided design and modeling for the surgical management of bone tumors and subsequent limb reconstruction provides accurate tumor removal with the salvage of a maximal amount of unaffected bone and precise endoprosthesis reconstruction. PMID:24267157

  9. Implant arthroplasty for the distal radioulnar joint.

    PubMed

    Scheker, Luis R

    2008-11-01

    The distal radioulnar joint (DRUJ) is a weight-bearing joint; the ulnar head is frequently excised either totally or partially and in some cases is fused because of degenerative, rheumatoid, or posttraumatic arthritis and treated with a "salvage procedure." The result of these procedures is the inability of those patients to lift even minor weight. Articles about these procedures report the ability to pronate and supinate, but they rarely discuss grip strength or lifting capacity. We present an alternative to the salvage procedures that allows full range of motions as well as the ability to grip and lift weights encountered in daily living, such as a gallon of milk. The Aptis total DRUJ replacement prosthesis (Aptis Medical, Louisville, KY), a bipolar self-stabilizing DRUJ endoprosthesis, restores the forearm function. The technique of implantation is presented here.

  10. [Rehabilitation of patients with laryngeal cancer after fronto-lateral resections with endoprosthesis].

    PubMed

    Ol'shanskiĭ, V O; Keshelava, V V; Klochikhin, A L

    1985-01-01

    A newly-developed polymer endoprosthesis was used at the second stage of combined treatment of 20 patients with stage II--III laryngeal cancer to prevent persistent stenosis following resection of the larynx and to assure an earlier rehabilitation. Endoprosthesis was installed after fronto-lateral resection in all cases. The endoprosthesis was made from biologically-compatible materials on a preservative and regenerator agent-impregnated polyvinyl-pyrrolidone base. After being located in laryngeal lumen for 30--45 days, the prosthesis was removed endolaryngeally under out-patient hospital conditions and the cannula was taken out 6--10 days later. Within the following 12 months and longer, both laryngeal lumen and respiration were normal. PMID:4002675

  11. [Prophylactics and treatment of postoperative hernias of the lateral abdominal walls using polypropylene endoprosthesis].

    PubMed

    Sukovatykh, B S; Valuĭskaia, N M; Pravednikova, N V; Netiaga, A A; Kas'ianova, M A; Zhukovskiĭ, V A

    2011-01-01

    An analysis of complex examination and treatment of 151 patients after planned and performed surgical interventions on organs of the retroperitoneal space was made. The patients were divided into 4 groups. The first group (of comparison) included 46 patients who were treated by lumbotomy for different diseases of organs of the urinary system. In 35 patients of the second group (prophylactics) the indications were determined and in 20 patients preventive endoprosthesis of the lateral abdominal wall using polypropylene endoprosthesis was fulfilled. Herniotomy with plasty of the lateral abdominal wall using local tissues was fulfilled in 30 patients. Prosthesing hernioplasty of the lateral abdominal wall was fulfilled in 40 patients of the main group. It was found that preventive endoprosthesis of the lateral abdominal wall allowed prevention of progressing anatomo-functional i/isufficiency and the appearance of postoperative hernias. The application of polypropylene endoprosthesis for the treatment of postoperative hernias allows obtaining 36.4% more good results as compared with the control group, 21.7% decreased number of satisfactory results and no recurrent hernias.

  12. Malignant biliary obstruction complicated by ascites: Closure of the transhepatic tract with cyanoacrylate glue after placement of an endoprosthesis

    SciTech Connect

    Cekirge, Saruhan; Akhan, Okan; Ozmen, Mustafa; Saatci, Isil; Besim, Aytekin

    1997-05-15

    A new technique using cyanoacrylate glue is suggested for closing the transparenchymal tract following metallic endoprosthesis placement in a patient with malignant biliary obstruction complicated by ascites. With this technique, complications related to bile reflux through the transparenchymal tract would be avoided after transhepatic endoprosthesis placement in patients who have ascites. This technique would also be useful for avoiding bleeding following transhepatic portal venous puncture.

  13. [A novel knee endoprosthesis with a physiological joint shape. Part 1: Biomechanical basics and tribological studies].

    PubMed

    Frosch, K-H; Floerkemeier, T; Abicht, C; Adam, P; Dathe, H; Fanghänel, J; Stürmer, K M; Kubein-Meesenburg, D; Nägerl, H

    2009-02-01

    The natural tibiofemoral joint (TFJ) functions according to a roll-glide mechanism. In the stance phase (0-20 degrees flexion), the femur rolls backwards over the tibia plateau, while further flexion causes increased gliding. This kinematics is based on the principle of a quadruple joint. The four morphological axes of rotation are the midpoints of the curvatures of the medial and lateral femoral condyles and the medial and lateral tibia plateau. In addition, the medial and lateral compartments are shifted a few millimetres in a sagittal direction, the medial tibia plateau being concave and the lateral plateau convex. In most knee arthroplasties, these factors are not taken into account; instead they are equipped with symmetrical medial and lateral joint surfaces. Thereby, the midpoints of the curvatures of the sagittal contours of the lateral and medial joint surfaces, on the femoral as well as on the tibial sides, create a common axis of rotation which does not allow a physiological roll-glide mechanism. The goal of this study was therefore to report on the biomechanical basis of the natural knee and to describe the development of a novel knee endoprosthesis based on a mathematical model. The design of the structurally new knee joint endoprosthesis has, on the lateral side, a convex shape of the tibial joint surface in a sagittal cross section. Furthermore, from a mathematical point of view, this knee endoprosthesis possesses essential kinematic and static properties similar to those of a physiological TFJ. Within the framework of the authorization tests, the endoprosthesis was examined according to ISO/WC 14243 in a knee simulator. The abrasion rates were, thereby, lower than or at least as good as those for conventional endoprostheses. The presented data demonstrate a novel concept in knee arthroplasty, which still has to be clinically confirmed by long term results.

  14. Analysis of rehabilitation procedure following arthroplasty of the knee with the use of complete endoprosthesis

    PubMed Central

    Wilk-Frańczuk, Magdalena; Tomaszewski, Wiesław; Zemła, Jerzy; Noga, Henryk; Czamara, Andrzej

    2011-01-01

    Summary Background The use of endoprosthesis in arthroplasty requires adaptation of rehabilitation procedures in order to reinstate the correct model of gait, which enables the patient to recover independence and full functionality in everyday life, which in turn results in an improvement in the quality of life. Material/Methods We studied 33 patients following an initial total arthroplasty of the knee involving endoprosthesis. The patients were divided into two groups according to age. The range of movement within the knee joints was measured for all patients, along with muscle strength and the subjective sensation of pain on a VAS, and the time required to complete the ‘up and go’ test was measured. The gait model and movement ability were evaluated. The testing was conducted at baseline and after completion of the rehabilitation exercise cycle. Results No significant differences were noted between the groups in the tests of the range of movement in the operated joint or muscle strength acting on the knee joint. Muscle strength was similar in both groups. In the “up and go” task the time needed to complete the test was 2.9 seconds shorter after rehabilitation in Group 1 (average age 60.4), and 4.5 seconds shorter in Group 2 (average age 73.1)). Conclusions The physiotherapy procedures we applied, following arthroplasty of the knee with cemented endoprosthesis, brought about good results in both research groups of older patients. PMID:21358604

  15. Large mode radius resonators

    NASA Technical Reports Server (NTRS)

    Harris, Michael R.

    1987-01-01

    Resonator configurations permitting operation with large mode radius while maintaining good transverse mode discrimination are considered. Stable resonators incorporating an intracavity telescope and unstable resonator geometries utilizing an output coupler with a Gaussian reflectivity profile are shown to enable large radius single mode laser operation. Results of heterodyne studies of pulsed CO2 lasers with large (11mm e sup-2 radius) fundamental mode sizes are presented demonstrating minimal frequency sweeping in accordance with the theory of laser-induced medium perturbations.

  16. Eclipse radius measurements

    NASA Technical Reports Server (NTRS)

    Dunham, D. W.; Dunham, J. B.; Fiala, A. D.; Sofia, S.

    1981-01-01

    Methods for predicting the path edges and reducing observations of total solar eclipses for determining variations of the solar radius are described. Analyzed observations of the 1925 January eclipse show a 0.7 (arc second) decrease in the solar radius during the past fifty years.

  17. Hominid radius from the middle Pliocene of Lake Turkana, Kenya.

    PubMed

    Heinrich, R E; Rose, M D; Leakey, R E; Walker, A C

    1993-10-01

    A nearly complete left radius, KNM-ER 20419, was recovered from middle Pliocene sediments east of Lake Turkana, Kenya in 1988. Ape-like characteristics of the fossil include an eccentrically positioned articular fovea, relatively long radial neck, wide distal metaphysis, and large brachioradialis crest. The robustness of the radial neck in proportion to the radial head, and the semilunar shape of the distal diaphysis, however, clearly distinguish KNM-ER 20419 as hominid. The distal articular surface possesses a larger area for radius-lunate articulation than for radius and scaphoid, a radiocarpal arrangement that is associated with increased wrist adduction among quadrumanous climbers. Since this morphology is also found in hylobatids, Pongo, and other early australopithecines, it is argued to be plesiomorphic for hominoids. This further supports the argument that vertical climbing was an important locomotor behavior among both early hominoids and our more immediate prebipedal ancestors. PMID:8273826

  18. Effective Cleaning Radius Studies

    SciTech Connect

    Churnetski, B.V.

    2001-10-15

    This report discusses results of testing done in the Savannah River Laboratory half tank and full tank mockup facilities using kaolin clay slurries and the relationship between cleaning radius and pump and slurry characteristics.

  19. [APPLICATION OF PREPARATION OF COCARNIT FOR PATIENTS AFTER ENDOPROSTHESIS OF HIP AND KNEE JOINTS].

    PubMed

    Korzh, N A; Filippenko, V A; Leont'eva, F S; Tulyakov, V A; Bondarenko, S E

    2015-01-01

    In the article the results of clinical researches of efficiency of preparation of Cocarnit are resulted for patients after endoprosthesis of large joints. It is routine that for patients, receiving preparation of Cocarnit after the operation period there was a decline in the amount of complaints of patients on the total somatical state. Preparation of Ccocarnit was positively estimated outside patients, meaningful by-reactions, serving reason of abolition of preparation, was not marked. At the reception preparation of Cocarnit greater part of investigational laboratory indexes (table of contents of glucose, β-lipoproteines, total chondroitisulfates, TBC-productes (malonic dyaldehyde), activity of aspartataminotransferase, alkaline phosphatase and β-glutamyltranspeptidase), the indexes of clinical blood test and leucocytar indexes during a supervision did not have reliable differences from such as the persons of the control group, that confirms good bearab leness of the indicated preparation. Application preparation of Cocarnit for patients in composition the chart of treatment of patients after endoprosthesis of large joints brought maintenance over of cholesterol to the decline, glycoproteins, TBC-products (malonic dyaldehyde), activity of alaninaminotransferase, that specifies on normalizing influence of the indicated preparation in relation to the basic types of exchange of matters.

  20. [New compounds for improving wear behavior of a tumor knee endoprosthesis].

    PubMed

    Lehner, S; Steinhauser, E; Mittelmeier, W; Stur, S; Gradinger, R

    2001-03-01

    Wear of the central bushing made of ultra-high molecular weight polyethylene (PE-UHMW) of the hinged knee endoprosthesis of a tumour-resection system is the leading reason for revision. The aim of the study was to optimize the wear characteristics of the endoprosthesis on the basis of the tribological properties of new materials and an additional finite element (FE) calculation taking account of the given design. In screening tests the reference combination of PE-UHMW bushing and CoCr axis--used in the clinical setting--was first tested. The PE-UHMW bushing was then replaced by one made of each of the materials reinforced high-density polyethylene (PE-HD) and carbon fibre-reinforced epoxy resin (CFRP). In addition, a new material combination with an alumina ceramic bushing and a CFRP axis was investigated. In comparison with the reference combination PE-UHMW/metal, the combination of ceramic bushing and CFRP axis showed less wear. However, with the particular design of the prosthesis studied here, high mechanical loading applied experimentally resulted in mechanical failure. FE calculations confirmed these experimental results. Improvement of the wear characteristics of this specific implant caused therefore be achieved only by optimizing the bearing design.

  1. [APPLICATION OF PREPARATION OF COCARNIT FOR PATIENTS AFTER ENDOPROSTHESIS OF HIP AND KNEE JOINTS].

    PubMed

    Korzh, N A; Filippenko, V A; Leont'eva, F S; Tulyakov, V A; Bondarenko, S E

    2015-01-01

    In the article the results of clinical researches of efficiency of preparation of Cocarnit are resulted for patients after endoprosthesis of large joints. It is routine that for patients, receiving preparation of Cocarnit after the operation period there was a decline in the amount of complaints of patients on the total somatical state. Preparation of Ccocarnit was positively estimated outside patients, meaningful by-reactions, serving reason of abolition of preparation, was not marked. At the reception preparation of Cocarnit greater part of investigational laboratory indexes (table of contents of glucose, β-lipoproteines, total chondroitisulfates, TBC-productes (malonic dyaldehyde), activity of aspartataminotransferase, alkaline phosphatase and β-glutamyltranspeptidase), the indexes of clinical blood test and leucocytar indexes during a supervision did not have reliable differences from such as the persons of the control group, that confirms good bearab leness of the indicated preparation. Application preparation of Cocarnit for patients in composition the chart of treatment of patients after endoprosthesis of large joints brought maintenance over of cholesterol to the decline, glycoproteins, TBC-products (malonic dyaldehyde), activity of alaninaminotransferase, that specifies on normalizing influence of the indicated preparation in relation to the basic types of exchange of matters. PMID:27089730

  2. The Possibilities to Decrease the Coefficient of Friciton Between Head and Socket of the Endoprosthesis of Hip Joint

    NASA Astrophysics Data System (ADS)

    Haringová, Andrea; Stračár, Karol; Prikkel, Karol

    2014-12-01

    The article deals with the question of physical parameters that could positively influence the overall lifetime of hip joint endoprosthesis. As the important physical parameter it was selected the coefficient of friction. The contribution offers possibilities how to decrease the coefficient of friction and experimentally test these assumptions

  3. Two-wave propagation in in vitro swine distal ulna

    NASA Astrophysics Data System (ADS)

    Mano, Isao; Horii, Kaoru; Matsukawa, Mami; Otani, Takahiko

    2015-07-01

    Ultrasonic transmitted waves were obtained in an in vitro swine distal ulna specimen, which mimics a human distal radius, that consists of interconnected cortical bone and cancellous bone. The transmitted waveforms appeared similar to the fast waves, slow waves, and overlapping fast and slow waves measured in the specimen after removing the surface cortical bone (only cancellous bone). In addition, the circumferential waves in the cortical bone and water did not affect the fast and slow waves. This suggests that the fast-and-slow-wave phenomenon can be observed in an in vivo human distal radius.

  4. Distal splenorenal shunt

    MedlinePlus

    ... shunt procedure; Renal - splenic venous shunt; Warren shunt; Cirrhosis - distal splenorenal; Liver failure - distal splenorenal ... hepatitis Blood clots Certain congenital disorders Primary biliary cirrhosis When blood cannot flow normally through the portal ...

  5. Distal Convoluted Tubule

    PubMed Central

    Ellison, David H.

    2014-01-01

    The distal convoluted tubule is the nephron segment that lies immediately downstream of the macula densa. Although short in length, the distal convoluted tubule plays a critical role in sodium, potassium, and divalent cation homeostasis. Recent genetic and physiologic studies have greatly expanded our understanding of how the distal convoluted tubule regulates these processes at the molecular level. This article provides an update on the distal convoluted tubule, highlighting concepts and pathophysiology relevant to clinical practice. PMID:24855283

  6. Whole bone geometry and bone quality in distal forearm fracture.

    PubMed

    Parkinson, Ian H; Fazzalari, Nicola L

    2008-09-01

    Fracture of the distal radius is a sentinel for future increased risk of other "osteoporotic" fractures, in which the peak age for incidence of distal radius fracture is 5 to 10 years before that for spine and hip fractures. Mean bone mineral density (BMD) of the distal radius was lower in patients with osteoporosis compared with age- and sex-matched normal subjects. However, it has been shown that to predict the strength of the distal radius at the site where fractures occur requires more than measurement of bone mineral content (BMC) or BMD. Only moderate correlations have been found between forearm sites, which may be a result of differences in bone composition between sites. Different forearm sites may be used interchangeably for diagnostic purposes, but the prognostic value is not known. Using the distal radius as a screening tool for identifying individuals at risk of "osteoporotic" fracture shows that forearm site selection and accuracy of measurement can be important confounders in group studies.Improving resolution of computed tomography (CT) scanners has enabled quantitation of cortical bone density and cortical thickness. These measurements have enabled the mechanism of bone loss in the distal radius to be elucidated and show that, after menopause, bone loss is primarily through thinning of the cortex. CT imaging allows the precise localization of bone changes in individuals and should be of value in the assessment of the severity of osteoporosis. It also shows that this technology has the potential to determine the efficacy of therapeutic interventions. A concerted effort has been made to elucidate the interrelationships between the amount of bone and the geometry and that clinical imaging of BMC and/or cross-sectional area in the radius would provide improved prediction of an individual's risk of fracture.The technological tools are available, in the clinic, to accurately measure the 3-dimensional (3D) geometry of the distal radius and the amount of

  7. CEMENTLESS ENDOPROSTHESIS IN THE TREATMENT OF GIANT CELL TUMOR OF THE TIBIA: EIGHTEEN YEARS OF EVOLUTION

    PubMed Central

    Mello, Glauco Pauka; Sonehara, Helio Ayabe; Neto, Mario Armani

    2015-01-01

    This is a case report on a giant cell tumor of the juxta-articular proximal tibia with a pathological fracture. A female patient presented pain and increased local volume after falling from her own height. She underwent clinical examination, radiographic examination and puncture biopsy. A diagnosis of giant cell tumor was made. The patient was then treated with tumor resection and use of an unconventional partial endoprosthesis of the tibia with preservation of the joint surface of the tibial plateau. The patient evolved with improvement of symptoms and maintenance of joint function of the operated limb, absence of recurrence and complications, without any need for reoperation over 18 years of follow-up. PMID:27026973

  8. Aortic Endoprosthesis for the Treatment of Native Aortic Coarctation and Concomitant Aneurysm in an Octogenarian Patient.

    PubMed

    Rabellino, Martín; Kotowicz, Vadim; Kenny, Alberto; Kohan, Andres Alejandro; García-Mónaco, Ricardo

    2015-11-01

    We report a case of an 82-year-old female patient with native coarctation of the aorta and poststenotic aneurysm of the descending thoracic aorta. On consultation, she was receiving 4 antihypertensive drugs, and physical examination revealed nonpalpable lower-limb pulses with intermittent claudication at 50 min. Because of her age, high surgical risk and combination of lesions, endovascular treatment was suggested. Placement of a Valiant thoracic aorta endoprosthesis followed by coarctation angioplasty was performed. At 48 hr, the patient was discharged on 1 antihypertensive drug, palpable pulses on both limbs and a normal ankle-brachial index. At 1 month follow-up, the patient remained as discharged and multislice computed tomography angiography depicted complete coarctation expansion without residual stenosis, exclusion of the aortic aneurysm, and no signs of endoleaks.

  9. Aortic Endoprosthesis for the Treatment of Native Aortic Coarctation and Concomitant Aneurysm in an Octogenarian Patient.

    PubMed

    Rabellino, Martín; Kotowicz, Vadim; Kenny, Alberto; Kohan, Andres Alejandro; García-Mónaco, Ricardo

    2015-11-01

    We report a case of an 82-year-old female patient with native coarctation of the aorta and poststenotic aneurysm of the descending thoracic aorta. On consultation, she was receiving 4 antihypertensive drugs, and physical examination revealed nonpalpable lower-limb pulses with intermittent claudication at 50 min. Because of her age, high surgical risk and combination of lesions, endovascular treatment was suggested. Placement of a Valiant thoracic aorta endoprosthesis followed by coarctation angioplasty was performed. At 48 hr, the patient was discharged on 1 antihypertensive drug, palpable pulses on both limbs and a normal ankle-brachial index. At 1 month follow-up, the patient remained as discharged and multislice computed tomography angiography depicted complete coarctation expansion without residual stenosis, exclusion of the aortic aneurysm, and no signs of endoleaks. PMID:26318556

  10. ULTRASONIC ASSESSMENT OF THE RADIUS IN VITRO

    PubMed Central

    Le Floch, Vincent; Luo, Gangming; Kaufman, Jonathan J.; Siffert, Robert S.

    2008-01-01

    The overall objective of this research is to develop an ultrasonic system for non-invasive assessment of the distal radius. The specific objective of this study was to examine the relationship between geometrical features of cortical bone and ultrasound measurements in vitro. Nineteen radii were measured in through transmission in a water bath. A 3.5 MHz rectangular (1 cm × 4.8 cm) single element transducer served as the source and a 3.5 MHz rectangular (1 cm × 4.8 cm) linear array transducer served as the receiver. The linear array consisted of 64 elements with a pitch of 0.75 mm. Ultrasound measurements were carried out at a location that was 1/3 of the length from the distal end of each radius, and two net time delay parameters, τNetDW and τNetCW, associated with a direct wave (DW) and a circumferential wave (CW), respectively, were evaluated. The cortical thickness (CT), medullar thickness (MT) and cross-sectional area (CSA) of each radius was also evaluated based on a digital image of the cross-section at the “1/3” location. The linear correlations between CT and τNetDW was r = 0.91 (p<0.001) and between MT and τNetDW - τNetCW was r = 0.63 (p<0.05). The linear correlation between CSA and a non-linear combination of the two net time delays, τNetDW and τNetCW, was r = 0.95 (p<0.001). The study shows that ultrasound measurements can be used to non-invasively assess cortical bone geometrical features in vitro as represented by cortical thickness, medullar thickness and cross-sectional area. PMID:18692295

  11. Distal Myopathies: Case Studies.

    PubMed

    Shaibani, Aziz

    2016-08-01

    About 15% of myopathies present with distal weakness. Lack of sensory deficit, and preservation of sensory responses and deep tendon reflexes, favors a myopathic cause for distal weakness. Electromyogram confirms this diagnosis. Profuse spontaneous discharges are common in inflammatory, metabolic, and myofibrillar myopathy (MFM). If the clinical picture indicates a specific disease such as facioscapulohumeral muscular dystrophy (FSHD), genetic testing provides the quickest diagnosis. Otherwise, muscle biopsy can distinguish specific features. The common causes of myopathic distal weakness are FSHD, myotonic dystrophy, and inclusion body myositis. Other causes include MFM, distal muscular dystrophies, metabolic myopathies, and congenital myopathies. PMID:27445241

  12. Distal biceps brachii.

    PubMed

    Brigido, Monica Kalume; De Maeseneer, Michel; Morag, Yoav

    2013-02-01

    There has been a renewed interest in the recent literature with regard to the normal anatomy of the distal biceps tendon. Cadaveric studies have demonstrated that a large percentage of individuals have two independent muscle bellies, the short and the long head, with two distinct separate tendons attaching at the radial tuberosity. To avoid diagnostic errors that may have an impact on patient management in case of tendon injury, it is important to keep this anatomical variant in mind. Ultrasonography has been shown to be a useful imaging modality in the evaluation of disorders of the distal biceps brachii muscle and tendon. In this article, we review the relevant anatomy of the distal biceps brachii, the ultrasound technique with alternative approaches for optimum visualization of the distal tendon, and the most common pathologies in this region.

  13. Transphyseal Distal Humerus Fracture.

    PubMed

    Abzug, Joshua; Ho, Christine Ann; Ritzman, Todd F; Brighton, Brian

    2016-01-01

    Transphyseal distal humerus fractures typically occur in children younger than 3 years secondary to birth trauma, nonaccidental trauma, or a fall from a small height. Prompt and accurate diagnosis of a transphyseal distal humerus fracture is crucial for a successful outcome. Recognizing that the forearm is not aligned with the humerus on plain radiographs may aid in the diagnosis of a transphyseal distal humerus fracture. Surgical management is most commonly performed with the aid of an arthrogram. Closed reduction and percutaneous pinning techniques similar to those used for supracondylar humerus fractures are employed. Cubitus varus caused by a malunion, osteonecrosis of the medial condyle, or growth arrest is the most common complication encountered in the treatment of transphyseal distal humerus fractures. A corrective lateral closing wedge osteotomy can be performed to restore a nearly normal carrying angle.

  14. Distal humeral epiphyseal separation.

    PubMed

    Moucha, Calin S; Mason, Dan E

    2003-10-01

    Distal humeral epiphyseal separation is an uncommon injury that is often misdiagnosed upon initial presentation. To make a timely, correct diagnosis, the treating physician must have a thorough understanding of basic anatomical relationships and an awareness of the existence of this injury. This is a case of a child who sustained a separation of the distal humeral epiphysis, as well as multiple other bony injuries, secondary to child abuse.

  15. Simultaneous distal radial fractures and carpal bones injuries in children: a review article.

    PubMed

    Pretell-Mazzini, Juan; Carrigan, Robert B

    2011-09-01

    Accurate diagnosis is crucial in effectively managing and treating both the radial and carpal fractures. Injuries to the carpal bones are not usually associated with fractures of the distal radius; however, the presence of a distal radius fracture does not preclude an associated carpal injury. The purpose of this review article is to compile cases of past reported distal radius fractures and simultaneous carpal injuries to restate its low prevalence within the pediatric population while still serving as a collective reference for management and treatment. After an electronic literature search was performed, we identified 18 published articles and 28 cases dealing with combined distal radial and carpal bones injuries in the pediatric population. As the mechanism of injury is similar for both fractures, despite the low incidence, orthopedic surgeons need to rule out carpal injury with a distal forearm fracture. Failure to treat both injuries appropriately may result in an unsatisfactory clinical result.

  16. A New Distal Radioulnar Joint Prosthesis

    PubMed Central

    Schuurman, Arnold H.

    2013-01-01

    Pain and instability of the distal radioulnar joint (DRUJ) are common sequelae following a fracture of the distal radius. Many soft tissue procedures have been described, not all of which are successful. Ulnar head replacement prostheses are available but do not always provide stability. We designed a two-part, easy to implant, distal radioulnar prosthesis and implanted it in 19 patients. The first prototype was inserted in 2002 and is still in place. During the study, the design was changed twice, resulting in three groups with four patients in group A, five in group B, and ten in group C. Unfortunately all five prostheses in group B had to be removed because of loosening, while only two prostheses in group C had to be removed, for nonprosthetic reasons. For the 12 patients who retained their prosthesis, forearm function increased while grip strength increased significantly. Pain scores decreased and the Disabilities of the Arm, Shoulder, and Hand (DASH) score improved but remained high. We conclude that the prosthesis offers a new treatment option for ulnar instability following distal ulnar resection. PMID:24436843

  17. Vertebral Augmentation with Nitinol Endoprosthesis: Clinical Experience in 40 Patients with 1-Year Follow-up

    SciTech Connect

    Anselmetti, Giovanni Carlo; Manca, Antonio; Marcia, Stefano; Chiara, Gabriele; Marini, Stefano; Baroud, Gamal; Regge, Daniele; Montemurro, Filippo

    2013-05-08

    PurposeThis study was designed to assess the clinical outcomes of patients treated by vertebral augmentation with nitinol endoprosthesis (VNE) to treat painful vertebral compression fractures.MethodsForty patients with one or more painful osteoporotic VCF, confirmed by MRI and accompanied by back-pain unresponsive to a minimum 2 months of conservative medical treatment, underwent VNE at 42 levels. Preoperative and postoperative pain measured with Visual Analog Scale (VAS), disability measured by Oswestry Disability Index (ODI), and vertebral height restoration (measured with 2-dimensional reconstruction CT) were compared at last follow-up (average follow-up 15 months). Cement extravasation, subsequent fractures, and implant migration were recorded.ResultsLong-term follow-up was obtained in 38 of 40 patients. Both VAS and ODI significantly improved from a median of 8.0 (range 5–10) and 66 % (range 44–88 %) to 0.5 (range 0–8) and 6 % (range 6–66 %), respectively, at 1 year (p < 0.0001). Vertebral height measurements comparing time points increased in a statistically significant manner (ANOVA, p < 0.001). Overall cement extravasation rate was 9.5 %. Discal and venous leakage rates were 7.1 and 0 % respectively. No symptomatic extravasations occurred. Five of 38 (13.1 %) patients experienced new spontaneous, osteoporotic fractures. No device change or migration was observed.ConclusionsVNE is a safe and effective procedure that is able to provide long-lasting pain relief and durable vertebral height gain with a low rate of new fractures and cement leakages.

  18. Variability of the Solar Radius

    NASA Astrophysics Data System (ADS)

    Bertello, L.; Ulrich, R. K.

    2003-05-01

    Possible temporal variability of the solar radius is important as an indicator of internal energy storage and as a mechanism for changes in the total solar irradiance (TSI). Variations in the TSI with an amplitude of 0.1% have been observed from space for more than two decades. Although the variability of this solar output is definitely established, the detailed dependence of the rate of energy output on the level of solar magnetic activity has not yet been measured with enough continuity and precision to establish the correlation throughout the full solar cycle. Changes in the solar radius could account for a significant fraction of the total irradiance variations. However, studies of the solar radius variation have reported contradictory results in the form of both correlations and anticorrelations between the solar radius and, for example, the cycle of sunspot numbers. Most of these studies however, are affected by the highly inhomogeneous data used in the analysis. This factor becomes particularly critical in the case of measurements that cover a very long period of time. We present consistent solar radius measurements obtained from the Mt Wilson synoptic programme of solar magnetic observations carried out at the 150-foot tower. Two definitions of the solar radius are used: the longest reduced record beginning in 1975 is derived from the fit of a circle to the isophote having an intensity equal to 40%\\ of the central intensity and more recently we have developed a definition based on intensity fits within 16 sectors around the solar circumference. Ulrich and Bertello (Nature, 1995, 377, 214) have made a re-analysis of an older database correcting for such effects as scattered light and atmospheric refraction. The older database is brought up to date and compared to results based on the new radius definition as well as other published radius variations. This work was supported by NASA through grants NAG5-10905 and NAG5-11708 as well as by NSF through grant ATM

  19. Squeaking friction phenomena in ceramic hip endoprosthesis: Modeling and experimental validation

    NASA Astrophysics Data System (ADS)

    Ouenzerfi, G.; Massi, F.; Renault, E.; Berthier, Y.

    2015-06-01

    minimizing friction rising factors (such edge loading and situations promoting metal transfer or stripe wear) or by developing endoprosthesis design to avoid the unstable vibrations, regressing the squeaking emission to a negligible phenomenon.

  20. Distal Oblique Bundle Reinforcement for Treatment of DRUJ Instability

    PubMed Central

    Brink, Peter R. G.; Hannemann, Pascal F. W.

    2015-01-01

    Background Chronic, dynamic bidirectional instability in the distal radioulnar joint (DRUJ) is diagnosed clinically, based on the patient's complaints and the finding of abnormal laxity in the vicinity of the distal ulna. In cases where malunion is ruled out or treated and there are no signs of osteoarthritis, stabilization of the DRUJ may offer relief. To this end, several different techniques have been investigated over the past 90 years. Materials and Methods In this article we outline the procedure for a new technique using a tendon graft to reinforce the distal edge of the interosseous membrane. Description of Technique A percutaneous technique is used to harvest the palmaris longus tendon and to create a tunnel, just proximal to the sigmoid notch, through the ulna and radius in an oblique direction. By overdrilling the radial cortex, the knotted tendon can be pulled through the radius and ulna and the knot blocked at the second radial cortex, creating a strong connection between the radius and ulna at the site of the distal oblique bundle (DOB). The tendon is fixed in the ulna with a small interference screw in full supination, preventing subluxation of the ulna out of the sigmoid notch during rotation. Results Fourteen patients were treated with this novel technique between 2011 and October 2013. The QuickDASH score at 25 months postoperatively (range 16–38 months) showed an improvement of 32 points. Similarly, an improvement of 33 points (67–34 months) was found on the PRWHE. Only one recurrence of chronic, dynamic bidirectional instability in the DRUJ was observed. Conclusion This simple percutaneous tenodesis technique between radius and ulna at the position of the distal edge of the interosseous membrane shows promise in terms of both restoring stability and relieving complaints related to chronic subluxation in the DRUJ. PMID:26261750

  1. The Pb radius experiment (PREX)

    NASA Astrophysics Data System (ADS)

    Mammei, Juliette M.

    2013-10-01

    We report the first measurement of the parity-violating asymmetry APV in the elastic scattering of polarized electrons from 208Pb from the Lead Radius Experiment PREX which ran in Hall A at the Thomas Jefferson National Accelerator Facility (JLab). APV is sensitive to the radius of the neutron distribution Rn. The Z boson that mediates the weak neutral interaction couples mainly to neutrons and provides a clean, model-independent measurement of the RMS radius Rn of the neutron distribution in the nucleus and is a fundamental test of nuclear structure theory. The result, APV = 0.656±0.060(stat)±0.014(syst) ppm, corresponds to a difference between the radii of the neutron and proton distributions Rn-Rp = 0.33-0.18+0.16 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

  2. Laser differential confocal radius measurement.

    PubMed

    Zhao, Weiqian; Sun, Ruoduan; Qiu, Lirong; Sha, Dingguo

    2010-02-01

    A new laser differential confocal radius measurement (DCRM) is proposed for high precision measurement of radius. Based on the property of an axial intensity curve that the absolute zero precisely corresponds to the focus of the objective in a differential confocal system (DCS), DCRM uses the zero point of the DCS axial intensity curve to precisely identify the cat's-eye and confocal positions of the test lens, and measures the accurate distance between the two positions to achieve the high-precision measurement of radius of curvature (ROC). In comparison with the existing measurement methods, DCRM proposed has a high measurement precision, a strong environmental anti-interference capability and a low cost. The theoretical analyses and preliminary experimental results indicate that DCRM has a relative measurement error of better than 5 ppm. PMID:20174065

  3. Management of Giant Cell Tumour Radius in a Three Year old Child with an Improvised Technique

    PubMed Central

    Puri, Ajay; Gulia, Ashish; Sharma, Seema; Verma, Amit K

    2014-01-01

    Giant cell tumours of immature skeleton have a very low incidence and epi-metaphyseal location. We are presenting giant cell tumour distal radius in a skeletally immature patient; an uncontained defect with a large soft tissue component which was managed by wide excision and reconstruction with an improvised technique. PMID:25654002

  4. [The quality management in clinical diagnostic laboratory in conditions of the Federal Center of traumatology, orthopedics and endoprosthesis replacement of Minzdrav of Russia (Cheboksary)].

    PubMed

    Nikolaev, N S; Nazarova, V V; Dobrovol'skaia, N Iu; Orlova, A V; Pchelova, N N

    2014-10-01

    The article presents experience of clinical diagnostic laboratory of the Federal Center of traumatology, orthopedics and endoprosthesis replacement of Minzdrav of Russia (Cheboksary) in the area of quality management of medical laboratory services on the basis of evaluation of efficacy and effectiveness of processes. The factors effecting quality of functioning of clinical diagnostic laboratory are indicated. The criteria and indicators of efficacy of work of employees of clinical diagnostic laboratory are presented.

  5. Entrapment of Extensor Pollicis Longus Tendon after Volar Plating of a Smith Type Pediatric Distal Forearm Fracture.

    PubMed

    Franz, Torsten

    2016-06-01

    Extensor pollicis longus tendon entrapment is a rare complication of volarly displaced pediatric distal radius fractures. The few pediatric case reports have described tendon entrapment associated with conservative fracture treatment, or have been recognized at subsequent revision surgery after failure to achieve closed fracture reduction. A case of extensor pollicis longus tendon entrapment after open reduction and volar plate fixation of a pediatric distal forearm fracture is reported. This complication may also occur secondarily after open reduction and volar plating of the distal radius. PMID:27454642

  6. Delayed union of the distal ulna in a child after both bone forearm fracture.

    PubMed

    Fike, E A; Bartal, E

    1998-01-01

    Fractures of the distal third of the forearm are common in children. These fractures are known to heal readily and rapidly. We describe a 10-year-old boy who had a closed, low-energy fracture of the distal radius and ulna. The radius healed promptly, but the ipsilateral ulna had radiographic evidence of delayed union. We have not found a report of a nonunion of this kind in the literature. With the increasing use of internal fixation and the lack of guidance in the literature, we questioned the standard use of closed treatment. We treated this patient nonoperatively, despite the delay in union, and the fracture healed in 4 months.

  7. Radius of curvature controlled mirror

    DOEpatents

    Neil, George R.; Rathke, John Wickham; Schultheiss, Thomas John; Shinn, Michelle D.; Dillon-Townes, Lawrence A.

    2006-01-17

    A controlled radius of curvature mirror assembly comprising: a distortable mirror having a reflective surface and a rear surface; and in descending order from the rear surface; a counter-distortion plate; a flow diverter having a flow diverter aperture at the center thereof; a flow return plate having a flow return aperture at the center thereof; a thermal isolation plate having a thermal isolation plate aperture at the center thereof and a flexible heater having a rear surface and a flexible heater aperture at the center thereof; a double walled tube defining a coolant feed chamber and a coolant return chamber; said coolant feed chamber extending to and through the flow diverter aperture and terminating at the counter-distortion plate and the coolant return chamber extending to and through the thermal isolation backplate and terminating at the flow diverter; and a coolant feed and a coolant return exit at the rear of said flexible heater.

  8. [Carpal instability after fractures of the distal end of the radius].

    PubMed

    Morawiecki, P; Sosin, P; Dutka, J

    1999-01-01

    Evaluation of the scapho-lunate angle (SLA) was made on the lateral X-rays of 335 cases after Colles' fracture. Value of SLA over 65 degrees was accepted as the sign of the dorsal intercaleted segmental instability of the wrist (DISI). In the material was stated 84 cases (25%) of the DISI. Frequency of the incidence of the DISI was analysed according to fracture type and the age of the patient. More frequent incidence of the DISI was discovered in the intraarticular fractures (44%) than in the extraarticular (20%). The difference between fractures with or without dislocation was not so great (27% tp 21%). Increasing percent of the DISI was stated in the older age-groups (the greatest--49%--in the group after 70-years old).

  9. Distal convoluted tubule.

    PubMed

    McCormick, James A; Ellison, David H

    2015-01-01

    The distal convoluted tubule (DCT) is a short nephron segment, interposed between the macula densa and collecting duct. Even though it is short, it plays a key role in regulating extracellular fluid volume and electrolyte homeostasis. DCT cells are rich in mitochondria, and possess the highest density of Na+/K+-ATPase along the nephron, where it is expressed on the highly amplified basolateral membranes. DCT cells are largely water impermeable, and reabsorb sodium and chloride across the apical membrane via electroneurtral pathways. Prominent among this is the thiazide-sensitive sodium chloride cotransporter, target of widely used diuretic drugs. These cells also play a key role in magnesium reabsorption, which occurs predominantly, via a transient receptor potential channel (TRPM6). Human genetic diseases in which DCT function is perturbed have provided critical insights into the physiological role of the DCT, and how transport is regulated. These include Familial Hyperkalemic Hypertension, the salt-wasting diseases Gitelman syndrome and EAST syndrome, and hereditary hypomagnesemias. The DCT is also established as an important target for the hormones angiotensin II and aldosterone; it also appears to respond to sympathetic-nerve stimulation and changes in plasma potassium. Here, we discuss what is currently known about DCT physiology. Early studies that determined transport rates of ions by the DCT are described, as are the channels and transporters expressed along the DCT with the advent of molecular cloning. Regulation of expression and activity of these channels and transporters is also described; particular emphasis is placed on the contribution of genetic forms of DCT dysregulation to our understanding.

  10. Toll-like receptors and aseptic loosening of hip endoprosthesis-a potential to respond against danger signals?

    PubMed

    Lähdeoja, Tuomas; Pajarinen, Jukka; Kouri, Vesa-Petteri; Sillat, Tarvo; Salo, Jari; Konttinen, Yrjö T

    2010-02-01

    Bacterial remnants and subclinical biofilms residing on prosthesis surfaces have been speculated to play a role in hip implant loosening by opsonizing otherwise relatively inert wear particles. The innate immune system recognizes these microbial pathogen-associated molecular patterns (PAMPs) using Toll-like receptors (TLRs). Our objective was to evaluate the possible presence of TLRs in aseptic synovial membrane-like interface tissue. Bacterial culture-negative, aseptic (n = 4) periprosthetic synovial membrane-like tissue was compared to osteoarthritis synovial membrane (n = 5) for the presence of cells positive for all known human functional TLRs, stained using specific antibodies by immunohistochemistry, and evaluated using morphometry. In comparison to osteoarthtritic synovium, the number of TLR-positive cells was found to be increased in the aseptic setting, reflecting the considerable macrophage infiltration to the tissues investigated. Thus aseptic periprosthetic tissue seems to be very reactive to PAMPs. It has been recently recognized that TLR do not only respond to traditional PAMPs, but also to endogenous alarmings or danger signals released from necrotic and activated cells. Alarming-TLR interaction in the periprosthetic tissue might be a novel mechanism of aseptic loosening of endoprosthesis.

  11. Genetics Home Reference: distal arthrogryposis type 1

    MedlinePlus

    ... Conditions distal arthrogryposis type 1 distal arthrogryposis type 1 Enable Javascript to view the expand/collapse boxes. ... Open All Close All Description Distal arthrogryposis type 1 is a disorder characterized by joint deformities (contractures) ...

  12. Dislocation of the distal radioulnar joint associated with a transstyloid radiocarpal fracture dislocation. A case report and review of the literature.

    PubMed

    Stoffelen, D; Fortems, Y; De Smet, L; Broos, P

    1996-03-01

    Dislocations of the distal radio-ulnar joint (DRUJ) can be isolated or combined with fractures. Cases of DRUJ dislocations have been described with Galleazi fractures, open radius and ulna fractures and intraarticular fractures of the distal radius. We report a case of a volar DRUJ dislocation combined with a transstyloid radio-carpal dislocation. Because of severe instability of the wrist, open reduction of the radial styloid combined with an open reduction of the dislocated DRUJ is advised. PMID:8669257

  13. Mirror with thermally controlled radius of curvature

    DOEpatents

    Neil, George R.; Shinn, Michelle D.

    2010-06-22

    A radius of curvature controlled mirror for controlling precisely the focal point of a laser beam or other light beam. The radius of curvature controlled mirror provides nearly spherical distortion of the mirror in response to differential expansion between the front and rear surfaces of the mirror. The radius of curvature controlled mirror compensates for changes in other optical components due to heating or other physical changes. The radius of curvature controlled mirror includes an arrangement for adjusting the temperature of the front surface and separately adjusting the temperature of the rear surface to control the radius of curvature. The temperature adjustment arrangements can include cooling channels within the mirror body or convection of a gas upon the surface of the mirror. A control system controls the differential expansion between the front and rear surfaces to achieve the desired radius of curvature.

  14. [Fracture of the diaphyseal radius during Cyr wheel practice - an uncommon injury of wheel gymnastics].

    PubMed

    Kauther, M D; Rummel, S; Hussmann, B; Lendemans, S; Nast-Kolb, D; Wedemeyer, C

    2011-12-01

    The cyr wheel is a modified gymnastic wheel with only one ring that can lead to extreme forces on the gymnast. We report on a distal radius shaft fracture (AO 22 A 2.1) and a fracture of the styloid process of the ulna that occurred after holding on to a slipping Cyr wheel and exposition to high pressure on the lower arm. The fracture was fixed by screws and a plate. PMID:22161268

  15. Safety and efficacy of using the Viabahn endoprosthesis for percutaneous treatment of vascular access complications after transfemoral aortic valve implantation.

    PubMed

    De Backer, Ole; Arnous, Samer; Sandholt, Benjamin; Brooks, Matthew; Biasco, Luigi; Franzen, Olaf; Lönn, Lars; Bech, Bo; Søndergaard, Lars

    2015-04-15

    Vascular access complications (VACs) remain one of the biggest challenges when performing transcatheter aortic valve implantation (TAVI). This study aimed to investigate the short- and medium-term safety and efficacy of the Viabahn endoprosthesis (Gore, Flagstaff, AZ) when used to treat TAVI-induced vascular injury. Over a 40-month period, 354 patients underwent true percutaneous transfemoral (TF)-TAVI using a CoreValve and Prostar-XL closure system; this was our study population. A VAC leading to acute intervention occurred in 72 patients (20.3%) - of these, 18 were managed by balloon angioplasty, 48 were treated by Viabahn stenting (technical success rate 98%), and 6 needed surgical intervention. Overall, this approach resulted in a major VAC rate of 3.1% (n = 11) in our study cohort. Length of hospitalization and 30-day mortality rates were comparable in patients with a VAC treated by Viabahn stenting versus patients without vascular complications. Two patients (4.5%) presented with new-onset claudication; one of them had the stent implanted covering the deep femoral artery (DFA). At medium-term follow-up (median 372 days; range 55 to 978 days) duplex ultrasound showed 100% patency of the Viabahn endoprostheses with no signs of stent fracture or in-stent stenosis/occlusion. In conclusion, the use of self-expanding covered stents is safe and effective in case of TF-TAVI-induced vascular injury, with good short- and medium-term outcomes. Importantly, coverage of the DFA should be avoided. If confirmed by long-term (>5 years) follow-up studies, this strategy for treating TAVI-induced VAC may be used routinely in high-risk patients. PMID:25728645

  16. [Distal humerus fractures in children].

    PubMed

    Schneidmueller, D; Boettger, M; Laurer, H; Gutsfeld, P; Bühren, V

    2013-11-01

    Fractures of the distal humerus belong to the most common injuries of the upper arm in childhood. Most frequently occurring is the supracondylar fracture of the distal humerus. In these cases and in the second most common epicondylar fractures, the metaphysis is affected and these fractures are therefore extra-articular. They have to be distinguished from articular fractures regarding therapy and prognosis. The growth potential of the distal epiphysis is very limited as is the possibility of spontaneous correction so that major dislocations should not be left uncorrected. Unstable and especially dislocated articular fractures must be anatomically reconstructed employing various osteosynthetic techniques, mostly combined with immobilization. Insufficient reconstruction, growth disturbance and non-union can result in axial deformities, such as cubitus valgus and varus, restriction of motion, pain and nerve palsy.

  17. Chondromyxoid Fibroma of Radius: A Case Report

    PubMed Central

    Bagewadi, Rajakumar M.; Hippargi, Surekha B.

    2016-01-01

    Chondromyxoid fibroma (CMF) is a rare benign cartilaginous tumour accounting to less than 1% of bone tumours. It is most commonly seen in lower extremity involving tibia. CMF of radius is rare. We report a rare case of CMF of proximal radius in a 37-year-old female who presented with swelling and pain over right elbow. Wide local excision of proximal radius along with radial head was done and above elbow POP slab was applied for one month. Elbow range of movement exercises started after one month. PMID:27437232

  18. Genetics Home Reference: Laing distal myopathy

    MedlinePlus

    ... for This Page GeneReview: Laing Distal Myopathy Laing NG, Laing BA, Meredith C, Wilton SD, Robbins P, ... T, Bridges LR, Fabian V, Rozemuller A, Laing NG. Laing early onset distal myopathy: slow myosin defect ...

  19. Distal clavicle fractures in children☆

    PubMed Central

    Labronici, Pedro José; da Silva, Ricardo Rodrigues; Franco, Marcos Vinícius Viana; Labronici, Gustavo José; Pires, Robinson Esteves Santos; Franco, José Sergio

    2015-01-01

    Objective To analyze fractures of the distal clavicle region in pediatric patients. Methods Ten patients between the ages of five to eleven years (mean of 7.3 years) were observed. Nine patients were treated conservatively and one surgically. All the fractures were classified using the Nenopoulos classification system. Results All the fractures consolidated without complications. Conservative treatment was used for nine patients, of whom three were in group IIIB, three IIb, two IIa and one IV. The only patient who was treated surgically was a female patient of eleven years of age with a group IV fracture. Conclusion The treatment indication for distal fractures of the clavicle in children should be based on the patient's age and the displacement of the fragments. PMID:26962489

  20. Distal esophageal spasm: an update.

    PubMed

    Achem, Sami R; Gerson, Lauren B

    2013-09-01

    Distal esophageal spasm (DES) is an esophageal motility disorder that presents clinically with chest pain and/or dysphagia and is defined manometrically as simultaneous contractions in the distal (smooth muscle) esophagus in ≥20% of wet swallows (and amplitude contraction of ≥30 mmHg) alternating with normal peristalsis. With the introduction of high resolution esophageal pressure topography (EPT) in 2000, the definition of DES was modified. The Chicago classification proposed that the defining criteria for DES using EPT should be the presence of at least two premature contractions (distal latency<4.5 s) in a context of normal EGJ relaxation. The etiology of DES remains insufficiently understood, but evidence links nitric oxide (NO) deficiency as a culprit resulting in a disordered neural inhibition. GERD frequently coexists in DES, and its role in the pathogenesis of symptoms needs further evaluation. There is some evidence from small series that DES can progress to achalasia. Treatment remains challenging due in part to lack of randomized placebo-controlled trials. Current treatment agents include nitrates (both short and long acting), calcium-channel blockers, anticholinergic agents, 5-phosphodiesterase inhibitors, visceral analgesics (tricyclic agents or SSRI), and esophageal dilation. Acid suppression therapy is frequently used, but clinical outcome trials to support this approach are not available. Injection of botulinum toxin in the distal esophagus may be effective, but further data regarding the development of post-injection gastroesophageal reflux need to be assessed. Heller myotomy combined with fundoplication remains an alternative for the rare refractory patient. Preliminary studies suggest that the newly developed endoscopic technique of per oral endoscopic myotomy (POEM) may also be an alternative treatment modality. PMID:23892829

  1. Distal Femoral Complications Following Antegrade Intramedullary Nail Placement

    PubMed Central

    Fantry, Amanda J.; Elia, Gregory; Vopat, Bryan G.; Daniels, Alan H.

    2015-01-01

    While antegrade nailing for proximal and diaphyseal femur fractures is a commonly utilized fixation method with benefits including early mobilization and high rates of fracture union, both intraoperative and postoperative complications may occur. Intraoperative errors include leg length discrepancy, anterior cortical perforation, malreduction of the fracture, and neurovascular injury, and postoperative complications include nonunion, malunion, infection, and hardware failure. This case series reviews complications affecting the distal femur after intramedullary nailing including fracture surrounding a distal femoral interlocking screw (Case #1), nonunion after dynamization with nail penetration into the knee joint (Case #2), and anterior cortical perforation (Case #3). Prevention of intraoperative and postoperative complications surrounding intramedullary nailing requires careful study of the femoral anatomy and nail design specifications (radius of curvature), consideration of the necessity of distal interlocking screws, the need for close radiographic follow-up after nail placement with X-rays of the entire length of the nail, and awareness of possible nail penetration into the knee joint after dynamization. PMID:25874066

  2. Chondroblastoma of the distal phalanx.

    PubMed

    Gregory, James R; Lehman, Thomas P; White, Jeremy R; Fung, Kar-Ming

    2014-05-01

    Chondroblastoma is a rare, benign primary bone tumor that usually occurs at the epiphysis of long bones. The authors present an example of the diagnosis and successful treatment of this neoplasm in an exceedingly rare location in the distal phalanx. Clinical and radiographic outcomes after 68 months of follow-up are presented. A 15-year-old, right hand-dominant, boy developed painful swelling of the right ring finger. Radiographs revealed a radiolucent lesion of the distal phalanx with expansile remodeling of the bone. An excisional biopsy was performed with curettage and bone grafting of the lesion. The diagnosis of chondroblastoma was made based on pathologic evaluation of the biopsy specimen. Sixty-six months after surgical treatment, the patient was free of recurrence and metastatic disease with excellent clinical and functional outcomes. To the authors' knowledge, this represents only the second reported case of chondroblastoma of the distal phalanx. The diagnosis of chondroblastoma in this rare location was made by pathologic review of the resection specimen. It is imperative to confirm the diagnosis of any resected bone specimen even when the concern for an aggressive or malignant lesion is low. A tumor presenting in an unusual location may require a change in treatment or surveillance.

  3. Chondroblastoma of the distal phalanx.

    PubMed

    Gregory, James R; Lehman, Thomas P; White, Jeremy R; Fung, Kar-Ming

    2014-05-01

    Chondroblastoma is a rare, benign primary bone tumor that usually occurs at the epiphysis of long bones. The authors present an example of the diagnosis and successful treatment of this neoplasm in an exceedingly rare location in the distal phalanx. Clinical and radiographic outcomes after 68 months of follow-up are presented. A 15-year-old, right hand-dominant, boy developed painful swelling of the right ring finger. Radiographs revealed a radiolucent lesion of the distal phalanx with expansile remodeling of the bone. An excisional biopsy was performed with curettage and bone grafting of the lesion. The diagnosis of chondroblastoma was made based on pathologic evaluation of the biopsy specimen. Sixty-six months after surgical treatment, the patient was free of recurrence and metastatic disease with excellent clinical and functional outcomes. To the authors' knowledge, this represents only the second reported case of chondroblastoma of the distal phalanx. The diagnosis of chondroblastoma in this rare location was made by pathologic review of the resection specimen. It is imperative to confirm the diagnosis of any resected bone specimen even when the concern for an aggressive or malignant lesion is low. A tumor presenting in an unusual location may require a change in treatment or surveillance. PMID:24810830

  4. Biliary self-expandable metallic stent for unresectable malignant distal biliary obstruction: which is better: covered or uncovered?

    PubMed

    Isayama, Hiroyuki; Nakai, Yousuke; Kogure, Hirofumi; Yamamoto, Natsuyo; Koike, Kazuhiko

    2013-05-01

    Self-expandable metallic stents (SEMS) are a widely accepted biliary endoprosthesis for patients with unresectable malignant distal biliary obstruction. There are two types of SEMS: covered and uncovered. Uncovered SEMS (UCSEMS) embed into the biliary wall due to their mesh structure and self-expandability, and are resistant to migration. However, the disadvantage of UCSEMS is occlusion due to tumor ingrowth (TI) via the stent mesh, and TI is the main cause of UCSEMS occlusion. To overcome this, covered SEMS (CSEMS) were developed and showed longer patency than UCSEMS. However, migration due to the non-embedded stent body is the main cause of CSEMS dysfunction. There are some randomized studies comparing CSEMS and UCSEMS; however, the results are different according to each study. From one meta-analysis, CSEMS showed longer patency than UCSEMS. A literature review revealed that covered SEMS showed longer patency than UCSEMS. Some studies cannot clearly demonstrate the superiority of CSEMS, as the CSEMS used did not prevent TI or migration. Mechanical properties of SEMS may influence the occurrence of complications. A recent clinical study comparing the Covered Wallstent and the Covered WallFlex revealed superiority of the WallFlex for the prevention of migration. Reducing the axial force and increasing the radial force may lead to good results. Migration of CSEMS should be prevented by taking into consideration the mechanical properties of stents and development of anti-migration systems.

  5. Diminished Bone Strength Is Observed in Adult Women and Men Who Sustained a Mild Trauma Distal Forearm Fracture During Childhood

    PubMed Central

    Farr, Joshua N; Khosla, Sundeep; Achenbach, Sara J; Atkinson, Elizabeth J; Kirmani, Salman; McCready, Louise K; Melton, L Joseph; Amin, Shreyasee

    2015-01-01

    Children and adolescents who sustain a distal forearm fracture (DFF) owing to mild, but not moderate, trauma have reduced bone strength and cortical thinning at the distal radius and tibia. Whether these skeletal deficits track into adulthood is unknown. Therefore, we studied 75 women and 75 men (age range, 20 to 40 years) with a childhood (age <18 years) DFF and 150 sex-matched controls with no history of fracture using high-resolution peripheral quantitative computed tomography (HRpQCT) to examine bone strength (ie, failure load) by micro–finite element (µFE) analysis, as well as cortical and trabecular bone parameters at the distal radius and tibia. Level of trauma (mild versus moderate) was assigned using a validated classification scheme, blind to imaging results. When compared to sex-matched, nonfracture controls, women and men with a mild trauma childhood DFF (eg, fall from standing height) had significant reductions in failure load (p < 0.05) of the distal radius, whereas women and men with a moderate trauma childhood DFF (eg, fall while riding a bicycle) had values similar to controls. Consistent findings were observed at the distal tibia. Furthermore, women and men with a mild trauma childhood DFF had significant deficits in distal radius cortical area (p < 0.05), and significantly lower dual-energy X-ray absorptiometry (DXA)-derived bone density at the radius, hip, and total body regions compared to controls (all p < 0.05). By contrast, women and men with a moderate trauma childhood DFF had bone density, structure, and strength that did not differ significantly from controls. These findings in young adults are consistent with our observations in children/adolescents with DFF, and they suggest that a mild trauma childhood DFF may presage suboptimal peak bone density, structure, and strength in young adulthood. Children and adolescents who suffer mild trauma DFFs may need to be targeted for lifestyle interventions to help achieve improved skeletal

  6. A Maximum Radius for Habitable Planets.

    PubMed

    Alibert, Yann

    2015-09-01

    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope. PMID:26159097

  7. Nuclear charge radius of 8He.

    PubMed

    Mueller, P; Sulai, I A; Villari, A C C; Alcántara-Núñez, J A; Alves-Condé, R; Bailey, K; Drake, G W F; Dubois, M; Eléon, C; Gaubert, G; Holt, R J; Janssens, R V F; Lecesne, N; Lu, Z-T; O'Connor, T P; Saint-Laurent, M-G; Thomas, J-C; Wang, L-B

    2007-12-21

    The root-mean-square (rms) nuclear charge radius of 8He, the most neutron-rich of all particle-stable nuclei, has been determined for the first time to be 1.93(3) fm. In addition, the rms charge radius of 6He was measured to be 2.068(11) fm, in excellent agreement with a previous result. The significant reduction in charge radius from 6He to 8He is an indication of the change in the correlations of the excess neutrons and is consistent with the 8He neutron halo structure. The experiment was based on laser spectroscopy of individual helium atoms cooled and confined in a magneto-optical trap. Charge radii were extracted from the measured isotope shifts with the help of precision atomic theory calculations.

  8. A Maximum Radius for Habitable Planets.

    PubMed

    Alibert, Yann

    2015-09-01

    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.

  9. Delayed distal radio-ulnar joint instability after Galeazzi type fracture fixation in a child.

    PubMed

    Jettoo, P; de Kiewiet, Gp

    2010-10-15

    We report a rare case of delayed distal radio-ulnar joint instability with malunion of a Galeazzi-type radius fracture in a 10- year-old boy. He underwent operative intervention with flexible intramedullary nailing of the radius. He had careful clinical and intra-operative evaluation under image intensifier, and regular clinical and radiological assessments subsequently in clinic, and his distal radio-ulnar joint (DRUJ) was stable. He nonetheless developed DRUJ instability with malunion of radial midshaft fracture at 4 months. Corrective osteotomy for forearm fracture malunion is an uncommon procedure in children. He underwent a corrective radial osteotomy at the site of malunion, held with a Pennig external fixator, with reconstruction of the DRUJ subluxation. He made a good recovery with full restoration of wrist and forearm function, which was maintained at 17 months.

  10. Proton radius from electron scattering data

    NASA Astrophysics Data System (ADS)

    Higinbotham, Douglas W.; Kabir, Al Amin; Lin, Vincent; Meekins, David; Norum, Blaine; Sawatzky, Brad

    2016-05-01

    Background: The proton charge radius extracted from recent muonic hydrogen Lamb shift measurements is significantly smaller than that extracted from atomic hydrogen and electron scattering measurements. The discrepancy has become known as the proton radius puzzle. Purpose: In an attempt to understand the discrepancy, we review high-precision electron scattering results from Mainz, Jefferson Lab, Saskatoon, and Stanford. Methods: We make use of stepwise regression techniques using the F test as well as the Akaike information criterion to systematically determine the predictive variables to use for a given set and range of electron scattering data as well as to provide multivariate error estimates. Results: Starting with the precision, low four-momentum transfer (Q2) data from Mainz (1980) and Saskatoon (1974), we find that a stepwise regression of the Maclaurin series using the F test as well as the Akaike information criterion justify using a linear extrapolation which yields a value for the proton radius that is consistent with the result obtained from muonic hydrogen measurements. Applying the same Maclaurin series and statistical criteria to the 2014 Rosenbluth results on GE from Mainz, we again find that the stepwise regression tends to favor a radius consistent with the muonic hydrogen radius but produces results that are extremely sensitive to the range of data included in the fit. Making use of the high-Q2 data on GE to select functions which extrapolate to high Q2, we find that a Padé (N =M =1 ) statistical model works remarkably well, as does a dipole function with a 0.84 fm radius, GE(Q2) =(1+Q2/0.66 GeV2) -2 . Conclusions: Rigorous applications of stepwise regression techniques and multivariate error estimates result in the extraction of a proton charge radius that is consistent with the muonic hydrogen result of 0.84 fm; either from linear extrapolation of the extremely-low-Q2 data or by use of the Padé approximant for extrapolation using a larger

  11. A misdiagnosis of traumatic hypersupination of the distal radioulnar joint: a case report.

    PubMed

    Asopa, Vipin; Douglas, Robert J; Saies, Andrew D; Church, James S

    2013-01-01

    Traumatic hypersupination injury of the distal radioulnar joint is a rare injury, and occurs when sufficient supination force is applied to the joint so as to tear the volar radioulnar ligament, resulting in separation of the triangular fibrocartilage complex, and subluxation of the tendon of extensor carpi ulnaris. This allows the distal ulna to rotate such that the ulnar styloid comes to lie adjacent to the ulna notch of the radius. Treatment of this injury requires manipulation of the joint, under anaesthesia or sedation. We describe a case where posttraumatic radiological investigation of a patient with an anatomical variation of the wrist when in supination resembled a traumatic hypersupination injury of the distal radioulnar joint. A review of the literature has revealed this to be the first reported case of this type.

  12. Peripheral nerve blocks for distal extremity surgery.

    PubMed

    Offierski, Chris

    2013-10-01

    Peripheral nerve block is well suited for distal extremity surgery. Blocking the nerves at the distal extremity is easily done. It does not require ultrasound or stimulators to identify the nerve. Blocking nerves in the distal extremity is safe with low risk of toxicity. The effect of the nerve block is limited to the distribution of the nerve. The distal nerves in the lower extremity are sensory branches of the sciatic nerve. This provides a sensory block only. This has the advantage of allowing the patient to actively contract tendons in the foot and ambulate more quickly after surgery. PMID:24093651

  13. Stanmore non-invasive growing arthrodesis endoprosthesis in the reconstruction of complicated total knee arthroplasty: A case report.

    PubMed

    Gupta, A; Meswania, J; Blunn, G; Cannon, S R; Briggs, T W R

    2006-06-01

    As the number of primary and revision arthroplasties performed each year increases, the complexity of the reconstructive efforts also increases. A case of a patient with a total knee arthroplasty complicated with infection, deficient extensor mechanism, bone loss and limb shortening of 5.5 cm is reported. We describe an alternative surgical technique of reconstruction of the knee and lengthening of the limb using the Stanmore Non-Invasive Growing-Distal Femoral Prosthesis. The prosthesis had a magnetic disc attached to a gearbox. The generation of an external electromagnetic field caused the magnetic disc to rotate and lengthen the prosthesis. This reconstructive technique has not been described in the literature.

  14. Mass-Radius Relationships for Exoplanets

    NASA Astrophysics Data System (ADS)

    Swift, D. C.; Eggert, J. H.; Hicks, D. G.; Hamel, S.; Caspersen, K.; Schwegler, E.; Collins, G. W.; Nettelmann, N.; Ackland, G. J.

    2012-01-01

    For planets other than Earth, particularly exoplanets, interpretation of the composition and structure depends largely on comparing the mass and radius with the composition expected given their distance from the parent star. The composition implies a mass-radius relation which relies heavily on equations of state calculated from electronic structure theory and measured experimentally on Earth. We lay out a method for deriving and testing equations of state, and deduce mass-radius and mass-pressure relations for key, relevant materials whose equation of state (EOS) is reasonably well established, and for differentiated Fe/rock. We find that variations in the EOS, such as may arise when extrapolating from low-pressure data, can have significant effects on predicted mass-radius relations and on planetary pressure profiles. The relations are compared with the observed masses and radii of planets and exoplanets, broadly supporting recent inferences about exoplanet structures. Kepler-10b is apparently "Earth-like," likely with a proportionately larger core than Earth's, nominally 2/3 of the mass of the planet. CoRoT-7b is consistent with a rocky mantle over an Fe-based core which is likely to be proportionately smaller than Earth's. GJ 1214b lies between the mass-radius curves for H2O and CH4, suggesting an "icy" composition with a relatively large core or a relatively large proportion of H2O. CoRoT-2b is less dense than the hydrogen relation, which could be explained by an anomalously high degree of heating or by higher than assumed atmospheric opacity. HAT-P-2b is slightly denser than the mass-radius relation for hydrogen, suggesting the presence of a significant amount of matter of higher atomic number. CoRoT-3b lies close to the hydrogen relation. The pressure at the center of Kepler-10b is 1.5+1.2 - 1.0 TPa. The central pressure in CoRoT-7b is probably close to 0.8 TPa, though may be up to 2 TPa. These pressures are accessible by planar shock and ramp

  15. Measurement of the Radius of Neutron Stars

    NASA Astrophysics Data System (ADS)

    Guillot, Sebastien

    2012-07-01

    A physical understanding of the behavior of cold ultra-dense matter -- at and above nuclear density -- can only be achieved by the study of neutron stars. The recent 1.97+/-0.04 Msun measurement for PSR 1614-2230 suggests that strange quark matter and hyperons/kaons condensate equations of state (EoSs) are disfavored, in favor of hadronic EoSs. Over much of the neutron star mass-radius parameter space, the latter EoSs produce lines of nearly constant radii (within about 10%). We present a simultaneous spectral analysis of several globular cluster quiescent low-mass x-ray binaries where we require the radius to be the same among all neutron stars analyzed. Our (preliminary) results suggest a neutron star radius much smaller than previously reported, in the range 7.5-10 km (90% confidence). The Markov-Chain Monte-Carlo method and the Bayesian approach developed in this analysis permits including uncertainties in the distance, in the hydrogen column density, and possible contributions to the spectra due to unmodelled spectrally hard components.

  16. Measurement of the Radius of Neutron Stars

    NASA Astrophysics Data System (ADS)

    Guillot, Sebastien; Rutledge, R. E.; Servillat, M.; Webb, N.

    2013-01-01

    A physical understanding of the behavior of cold ultra dense matter - at and above nuclear density - can only be achieved by the study of neutron stars. The recent 1.97 ± 0.04 M⊙ measurement for PSR 1614-2230 suggests that strange quark matter and hyperons/kaons condensate equations of state (EoSs) are disfavored, in favor of hadronic EoSs. Over much of the neutron star mass-radius parameter space, the latter EoSs produce lines of nearly constant radii (within about 10%). We present a simultaneous spectral analysis of several globular cluster quiescent low-mass X-ray binaries where we require the radius to be the same among all neutron stars analyzed. Our (preliminary) results suggest a neutron star radius much smaller than previously reported, in the range 7.5-10 km (90% confidence). The Markov-Chain Monte-Carlo method and the Bayesian approach developed in this analysis permits including uncertainties in the distance, in the hydrogen column density, and possible contributions to the spectra due to unmodeled spectrally hard components.

  17. The effective pore radius of screen wicks

    SciTech Connect

    Imura, Hideaki; Kozai, Hiroaki; Ikeda, Yuji

    1994-10-01

    The effective pore radius in screen-wick heat pipes was investigated, which is very important for the prediction of maximum heat transfer rates due to capillary limitation. An equation for the effective pore radius of the screen wicks was derived based on the model of the screen geometry. The capillary height for stainless steel and phosphor bronze screens was measured using water, ethyl alcohol, and Freon 113 as the test liquids. The effect of surface treatment (acid cleaning and oxidation) on the capillary height was also examined. From the comparison of the experimental data for water and ethyl alcohol with those for Freon 113, it was indicated that the contact angle was 24.2{degree} for water and 16.9{degree} for ethyl alcohol. Consequently, it was found that the effective pore radius of the screen wicks could be predicted fairly well from the expression presented in this study, and that the contact angle should be taken into consideration to evaluate the maximum capillary pressure accurately.

  18. Electrode radius predicts lesion radius during radiofrequency energy heating. Validation of a proposed thermodynamic model

    SciTech Connect

    Haines, D.E.; Watson, D.D.; Verow, A.F. )

    1990-07-01

    Myocardial heating by transcatheter delivery of radiofrequency (RF) energy has been proposed as an effective means of arrhythmia ablation. A thermodynamic model describing the radial temperature gradient at steady state during RF-induced heating is proposed. If one assumes that RF power output is adjusted to maintain a constant electrode-tissue interface temperature at all times, then this thermodynamic model predicts that the radius of the RF-induced lesion will be directly proportional to the electrode radius. A total of 76 RF-induced lesions were created in a model of isolated canine right ventricular free wall perfused and superfused with oxygenated Krebs-Henseleit buffer. Electrode radius was varied between 0.75 and 2.25 mm. RF energy (500 kHz) was delivered for 90 seconds, and the power output was adjusted to maintain a constant electrode-tissue interface temperature of 60 degrees C. A strong linear correlation was observed between electrode radius and lesion radius in two dimensions: transverse (p = 0.0001, r = 0.85) and transmural (p = 0.0001, r = 0.89). With these data, the temperature correlation with irreversible myocardial injury in this model was calculated at 46.6-48.8 degrees C. Therefore, the proposed thermodynamic model closely predicts the observed relation between electrode radius and lesion size during RF myocardial heating.

  19. Distal metatarsal synostosis: a case report.

    PubMed

    Aspros, Dimitrios; Ananda-Rajan, Ethan; Jnr, Zdenak Klezl; Rajan, Rohan

    2014-09-01

    We report a rare case of distal metatarsal synostosis of the 4th and 5th metatarsals in an 11 year old male. He was referred with forefoot pain. Clinical examination and radiographs have confirmed an osseous connection of the distal 4th and 5th metatarsal. This was treated surgically with bony bridge excision and the patient is now asymptomatic.

  20. Distal symphalangism: a report of two families.

    PubMed

    Poush, J R

    1991-01-01

    This study describes distal symphalangism in 36 individuals in two families, one of which is the largest pedigree of this rare defect yet documented. Distal symphalangism is ankylosis or rigidity of the distal interphalangeal joints of the hands and/or feet. The findings of this report substantiate the mutation as an autosomal dominant phenotype. Several manifestations of distal symphalangism were observed, including the lack of cutaneous creases over affected joints, brachydactyly, fourth-finger hypophalangism, absent nails, and rudimentary nails. Variability ranged from just toes affected, to a single finger affected, to all fingers and all lesser toes affected. The most common expression of the mutant gene was rigid index fingers. Craniosynostosis, premature closure of the sutures of the skull, was encountered twice in the larger of the two families. It is a possible pleiotropic effect of distal symphalangism. PMID:2061594

  1. Distal symphalangism: a report of two families.

    PubMed

    Poush, J R

    1991-01-01

    This study describes distal symphalangism in 36 individuals in two families, one of which is the largest pedigree of this rare defect yet documented. Distal symphalangism is ankylosis or rigidity of the distal interphalangeal joints of the hands and/or feet. The findings of this report substantiate the mutation as an autosomal dominant phenotype. Several manifestations of distal symphalangism were observed, including the lack of cutaneous creases over affected joints, brachydactyly, fourth-finger hypophalangism, absent nails, and rudimentary nails. Variability ranged from just toes affected, to a single finger affected, to all fingers and all lesser toes affected. The most common expression of the mutant gene was rigid index fingers. Craniosynostosis, premature closure of the sutures of the skull, was encountered twice in the larger of the two families. It is a possible pleiotropic effect of distal symphalangism.

  2. Robotic distal pancreatectomy: a valid option?

    PubMed

    Jung, M K; Buchs, N C; Azagury, D E; Hagen, M E; Morel, P

    2013-10-01

    Although reported in the literature, conventional laparoscopic approach for distal pancreatectomy is still lacking widespread acceptance. This might be due to two-dimensional vision and decreased range of motion to reach and safely dissect this highly vascularized retroperitoneal organ by laparoscopy. However, interest in minimally invasive access is growing ever since and the robotic system could certainly help overcome limitations of the laparoscopic approach in the challenging domain of pancreatic resection, notably in distal pancreatectomy. Robotic distal pancreatectomy with and without spleen preservation has been reported with encouraging outcomes for benign and borderline malignant disease. As a result of upgraded endowristed manipulation and three-dimensional visualization, improved outcome might be expected with the launch of the robotic system in the procedure of distal pancreatectomy. Our aim was thus to extensively review the current literature of robot-assisted surgery for distal pancreatectomy and to evaluate advantages and possible limitations of the robotic approach.

  3. Chondroblastoma of Diaphysis of Radius in a Seven Year Old Child

    PubMed Central

    Punit, Abhinandan; Nadkarni, Sambaprasad; Doomra, Tanvir

    2014-01-01

    Introduction: Chondroblastoma is a rare, benign tumor derived from chondroblasts, is almost exclusively an epiphyseal lesion, although it may secondarily extend into metaphysis. It is most commonly found in lower extremity with most common sites being distal femur followed by proximal femur, proximal humerus and proximal tibia. It is the purpose of the report to describe chondroblastoma in a seven year old child in the diaphyseal area of radius which is a rare entity & frequently presents as diagnostic dilemma. Case Report: The authors report a case of chondroblastoma involving the diaphyseal area of radius in a seven year old female child. She presented with pain and swelling around the left distal third forearm for eight months. Wide excision of tumor was performed and the defect was bridged with avascular fibular auto graft, secured to host bone with k-wires and dynamic compression plate to achieve osteosynthesis. Conclusion: Pure metaphyseal and/or diaphyseal chondroblastomas are exceedingly rare. A presumptive diagnosis may be considered in the appropriate age group in the presence of chondroid matrix, perilesional edema, periosteal reaction, and marginal sclerosis. Regardless of all the diagnostic possibilities biopsy may still be required. However, knowledge of this entity will help make the final diagnosis and guide the correct treatment. PMID:27298978

  4. AMC: amyoplasia and distal arthrogryposis.

    PubMed

    Kimber, Eva

    2015-12-01

    Arthrogryposis multiplex congenita (AMC) is a heterogeneous condition defined as multiple congenital joint contractures in two or more body areas. The common pathogenesis is impaired fetal movements. Amyoplasia, the most frequent form, is a sporadically occurring condition with hypoplastic muscles and joint contractures. Distal arthrogryposis (DA) syndromes are often hereditary, and joint involvement is predominantly in the hands and feet. In a Swedish study, 131 patients with arthrogryposis were investigated. The most frequent diagnoses were amyoplasia and DA. In amyoplasia, muscle strength was found to be more important than joint range of motion (ROM) for motor function. In DA, muscle weakness was present in 44 % of investigated patients. The clinical findings were found to be highly variable between families and also within families with DA. Fetal myopathy due to sarcomeric protein dysfunction can cause DA. An early multidisciplinary team evaluation of the child with arthrogryposis for specific diagnosis and planning of treatment is recommended. Attention should be directed at the development of muscle strength with early stimulation of active movements. Immobilization should be minimized.

  5. Distal phalanges of Eosimias and Hoanghonius.

    PubMed

    Gebo, Daniel L; Beard, K Christopher; Ni, Xijun; Dagosto, Marian

    2015-09-01

    Seven primate distal phalanges have been identified from two middle Eocene fossil localities (Locality 1 and Nanbaotou) in the Yuanqu Basin, China, providing the first evidence of distal phalangeal morphology in Asian Eocene adapiform and eosimiid primates. The bones are best allocated to the basal anthropoid Eosimias centennicus and to hoanghoniine adapiforms. All distal phalangeal specimens display a morphology consistent with nail-bearing fingers and toes. The hallucal distal phalanx of the basal anthropoid Eosimias is more similar to that of primitive tarsiiforms than to crown group anthropoids. The adapiform distal phalanges from Locality 1 are allocated to Hoanghonius stehlini while those from Nanbaotou are tentatively assigned to an indeterminate hoanghoniine because dental remains of adapiforms have yet to be identified from this site. The distal phalangeal anatomy of hoanghoniines differs slightly from that documented for adapines and notharctines. One distal phalanx from Locality 1 shows a second pedal digit "grooming claw" morphology as noted for notharctines by Maiolino et al. (2012) and cercamoniines by Von Koenigswald et al. (2012).

  6. An Exoplanet Radius and Transit Timing Survey

    NASA Astrophysics Data System (ADS)

    Deming, Drake; Jennings, Jonald; Sada, Pedro

    2010-02-01

    Many exoplanet systems contain Jupiter-mass planets on close-in orbits. Theories of planetary system formation account for these hot Jupiters as being end states of inward migration. Variants of those theories also predict terrestrial planets to be captured in mean motion resonance with the hot Jupiters. A continuing explosion of discoveries by transit surveys have given us a sample of 45 hot Jupiters transiting planets brighter than V=13. A transit timing survey of these systems could detect hot Earths in resonance, via the large (~ 180 second) perturbations they induce on the giant planet transits. Moreover, the discovery photometry for these systems usually provides only relatively coarse photometric precision, but larger-aperture follow-up can determine the giant planet radius to a precision limited only by knowledge of the stellar mass, and thereby reveal the diversity of giant exoplanet structure, such as the presence of heavy element cores. The relatively large sample now available means that a radius- and transit timing-survey is well matched to classical observing and telescope scheduling. We propose continued observations to perform transit photometry using FLAMINGOS on the 2.1-meter in the J-band, where stellar limb darkening is minimal and transit photometry has excellent sensitivity to planetary radii and shifts in transit time.

  7. An Exoplanet Radius and Transit Timing Survey

    NASA Astrophysics Data System (ADS)

    Deming, Drake; Jennings, Jonald; Sada, Pedro

    2009-08-01

    Many exoplanet systems contain Jupiter-mass planets on close-in orbits. Theories of planetary system formation account for these hot Jupiters as being end states of inward migration. Variants of those theories also predict terrestrial planets to be captured in mean motion resonance with the hot Jupiters. A recent explosion of discoveries by transit surveys have given us a sample of 37 hot Jupiters transiting planets brighter than V=13. A transit timing survey of these systems could detect hot Earths in resonance, via the large (~ 180 second) perturbations they induce on the giant planet transits. Moreover, the discovery photometry for these systems usually provides only relatively coarse photometric precision, but larger-aperture follow-up can determine the giant planet radius to a precision limited only by knowledge of the stellar mass, and thereby reveal the diversity of giant exoplanet structure, such as the presence of heavy element cores. The relatively large sample now available means that a radius- and transit timing-survey is well matched to classical observing and telescope scheduling. We propose continued observations to perform transit photometry using FLAMINGOS on the 2.1-meter in the J-band, where stellar limb darkening is minimal and transit photometry has excellent sensitivity to planetary radii and shifts in transit time.

  8. Nuclear Charge Radius of Lithium-11

    SciTech Connect

    Sanchez, Rodolfo; Nortershauser, W.; Dax, A. ..; Ewald, G.; Gotte, S.; Kirchner, R. G.; Kluge, H. J.; Kuhl, T. H.; Wojtaszek, A.; Bushaw, Bruce A.; Drake, Gordon W. F.; Yan, Z. C.; Zimmermann, Claus; Albers, Daniel; Behr, John; Bricault, Pierre; Dilling, Jens; Dombsky, Marik; Lassen, J.; Levy, C.D. P.; Pearson, Matthew; Prime, Erika; Ryjkov, Vladimir L.

    2006-07-01

    We have determined the nuclear charge radius of 11Li by high-precision laser spectroscopy. The experiment was performed at the TRIUMF-ISAC facility where the 7Li-11Li isotope shift was measured in the 2s to 3s electronic transition using Doppler-free two-photon spectroscopy with a relative accuracy better than 10 5. The accuracy reached in previous experiments on the other lithium isotopes was improved. Most of the isotope shifts measured in the experiment are due to difference in the mass of the nuclei but small contributions are produced by the change in proton distribution, QED and relativistic effects have to be taken into account as well. By comparing the experimental results with sophisticated atomic calculations of the mass dependent effect the nuclear charge radii of the lithium isotopes are found to decrease monotonically from 6Li to 9Li while the nuclear charge radius of 11Li is about 11% larger than that of 9Li.

  9. What radius does the conventional keratometer measure?

    PubMed

    Bennett, A G; Rabbetts, R B

    1991-07-01

    The reflected mire images used in conventional keratometry suffer from oblique astigmatism, resulting in separated sagittal and tangential image planes. Further complications arise if the cornea is assumed to be aspherical. To investigate the consequential effects on the readings--hitherto largely neglected--ray tracing methods were applied to two hypothetical models. One was representative of modern variable-doubling constructions and the other of the Javal-Schiötz design. Both are seen to require the tangential image plane to be focused. Given a spherical cornea, the measured tangential image height can be converted into an accurate radius reading by means of a linear calibration formula. In the Javal-Schiötz design, a non-linear correction is needed for this. Appropriately calibrated in these ways, each model is shown to give readings extremely close to the sagittal radius of curvature at the point of incidence when applied to corneae of conicoidal form. Extensive numerical results are tabulated and the detailed calculating schemes illustrated by worked examples.

  10. Distal Peripheral Polyneuropathy in a Great Dane

    PubMed Central

    Henricks, Paul M.; Steiss, Jan; Petterson, Joanne D.

    1987-01-01

    A spayed female five year old Great Dane dog was diagnosed as having a chronic, progressive, symmetrical distal polyneuropathy and concurrent hypothyroidism. Axonal degeneration and segmental demyelination were evident in teased nerve fiber preparations. Clinical signs included hindlimb weakness and muscle atrophy of the head and distal limbs. Diagnosis was based on clinical, electrophysiological, and nerve and muscle biopsy findings. Thyroxine supplementation for one month was of no benefit. The etiology of the polyneuropathy was not established but several causes were considered. The extent of demyelination in our case was of greater magnitude than described in a previous report of a similar idiopathic distal symmetrical polyneuropathy in a Great Dane. PMID:17422753

  11. Biomechanical stability of a volar locking-screw plate versus fragment-specific fixation in a distal radius fracture model.

    PubMed

    Cooper, Ellis O; Segalman, Keith A; Parks, Brent G; Sharma, Krishna M; Nguyen, Augustine

    2007-04-01

    Eight matched pairs of cadaveric radii were osteotomized by removing a 4-mm dorsal wedge of bone at the level of the sigmoid notch designed to simulate dorsal comminution. They were then fixed with either a volar locking-screw plate or fragment-specific fixation. All constructs underwent biomechanical testing in a custom-designed, custom-fabricated 4-point bending device. No statistically significant difference in stiffness was noted between the groups. Linear displacement and angulation at the osteotomy site were significantly less in the group with fragment-specific fixation at loads expected to be encountered during postoperative rehabilitation. Angulation at the osteotomy site was significantly less in the locking-screw plate group at higher loads.

  12. Premenopausal Women with a Distal Radial Fracture Have Deteriorated Trabecular Bone Density and Morphology Compared with Controls without a Fracture

    PubMed Central

    Rozental, Tamara D.; Deschamps, Laura N.; Taylor, Alexander; Earp, Brandon; Zurakowski, David; Day, Charles S.; Bouxsein, Mary L.

    2013-01-01

    Background: Measurement of bone mineral density by dual x-ray absorptiometry combined with clinical risk factors is currently the gold standard in diagnosing osteoporosis. Advanced imaging has shown that older patients with fragility fractures have poor bone microarchitecture, often independent of low bone mineral density. We hypothesized that premenopausal women with a fracture of the distal end of the radius have similar bone mineral density but altered bone microarchitecture compared with control subjects without a fracture. Methods: Forty premenopausal women with a recent distal radial fracture were prospectively recruited and matched with eighty control subjects without a fracture. Primary outcome variables included trabecular and cortical microarchitecture at the distal end of the radius and tibia by high-resolution peripheral quantitative computed tomography. Bone mineral density at the wrist, hip, and lumbar spine was also measured by dual x-ray absorptiometry. Results: The fracture and control groups did not differ with regard to age, race, or body mass index. Bone mineral density was similar at the femoral neck, lumbar spine, and distal one-third of the radius, but tended to be lower in the fracture group at the hip and ultradistal part of the radius (p = 0.06). Trabecular microarchitecture was deteriorated in the fracture group compared with the control group at both the distal end of the radius and distal end of the tibia. At the distal end of the radius, the fracture group had lower total density and lower trabecular density, number, and thickness compared with the control group (–6% to –14%; p < 0.05 for all). At the distal end of the tibia, total density, trabecular density, trabecular thickness, and cortical thickness were lower in the fracture group than in the control group (–7% to –14%; p < 0.01). Conditional logistic regression showed that trabecular density, thickness, separation, and distribution of trabecular separation remained

  13. Villous adenoma of the distal appendix.

    PubMed

    Taylor, J V; Thomas, M G; Kelly, S; Sutton, R

    1997-04-01

    Villous adenoma confined to the distal appendix has not been previously reported in conjunction with acute apendicitis. The presence of an adenoma indicates a need for further investigation due to an association with neoplasia elsewhere.

  14. Understanding the mass-radius relation for sub-Neptunes: radius as a proxy for composition

    SciTech Connect

    Lopez, Eric D.; Fortney, Jonathan J.

    2014-09-01

    Transiting planet surveys like Kepler have provided a wealth of information on the distribution of planetary radii, particularly for the new populations of super-Earth- and sub-Neptune-sized planets. In order to aid in the physical interpretation of these radii, we compute model radii for low-mass rocky planets with hydrogen-helium envelopes. We provide model radii for planets 1-20 M {sub ⊕}, with envelope fractions 0.01%-20%, levels of irradiation 0.1-1000 times Earth's, and ages from 100 Myr to 10 Gyr. In addition we provide simple analytic fits that summarize how radius depends on each of these parameters. Most importantly, we show that at fixed H/He envelope fraction, radii show little dependence on mass for planets with more than ∼1% of their mass in their envelope. Consequently, planetary radius is to a first order a proxy for planetary composition, i.e., H/He envelope fraction, for Neptune- and sub-Neptune-sized planets. We recast the observed mass-radius relationship as a mass-composition relationship and discuss it in light of traditional core accretion theory. We discuss the transition from rocky super-Earths to sub-Neptune planets with large volatile envelopes. We suggest ∼1.75 R {sub ⊕} as a physically motivated dividing line between these two populations of planets. Finally, we discuss these results in light of the observed radius occurrence distribution found by Kepler.

  15. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  16. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  17. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Corneal radius measuring device. 886.1450 Section 886.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius...

  18. Archaic and modern human distal humeral morphology.

    PubMed

    Yokley, Todd R; Churchill, Steven E

    2006-12-01

    The morphology of the proximal ulna has been shown to effectively differentiate archaic or premodern humans (such as Homo heidelbergensis and H. neanderthalensis) from modern humans (H. sapiens). Accordingly, the morphology of adjacent, articulating elements should be able to distinguish these two broad groups as well. Here we test the taxonomic utility of another portion of the elbow, the distal humerus, as a discriminator of archaic and modern humans. Principal components analysis was employed on a suite of log-raw and log-shape distal humeral measures to examine differences between Neandertal and modern human distal humeri. In addition, the morphological affinities of Broken Hill (Kabwe) E.898, an archaic human distal humeral fragment from the middle Pleistocene of Zambia, and five Pliocene and early Pleistocene australopith humeri were assessed. The morphometric analyses effectively differentiated the Neandertals from the other groups, while the Broken Hill humerus appears morphologically similar to modern human distal humeri. Thus, an archaic/modern human dichotomy-as previously reported for proximal ulnar morphology-is not supported with respect to distal humeral morphology. Relative to australopiths and modern humans, Neandertal humeri are characterized by large olecranon fossae and small distodorsal medial and lateral pillars. The seeming disparity in morphological affinities of proximal ulnae (in which all archaic human groups appear distinct from modern humans) and distal humeri (in which Neandertals appear distinct from modern humans, but other archaic humans do not) is probably indicative of a highly variable, possibly transitional population of which our knowledge is hampered by sample-size limitations imposed by the scarcity of middle-to-late Pleistocene premodern human fossils outside of Europe.

  19. Management of distal humeral coronal shear fractures

    PubMed Central

    Yari, Shahram S; Bowers, Nathan L; Craig, Miguel A; Reichel, Lee M

    2015-01-01

    Coronal shear fractures of the distal humerus are rare, complex fractures that can be technically challenging to manage. They usually result from a low-energy fall and direct compression of the distal humerus by the radial head in a hyper-extended or semi-flexed elbow or from spontaneous reduction of a posterolateral subluxation or dislocation. Due to the small number of soft tissue attachments at this site, almost all of these fractures are displaced. The incidence of distal humeral coronal shear fractures is higher among women because of the higher rate of osteoporosis in women and the difference in carrying angle between men and women. Distal humeral coronal shear fractures may occur in isolation, may be part of a complex elbow injury, or may be associated with injuries proximal or distal to the elbow. An associated lateral collateral ligament injury is seen in up to 40% and an associated radial head fracture is seen in up to 30% of these fractures. Given the complex nature of distal humeral coronal shear fractures, there is preference for operative management. Operative fixation leads to stable anatomic reduction, restores articular congruity, and allows initiation of early range-of-motion movements in the majority of cases. Several surgical exposure and fixation techniques are available to reconstruct the articular surface following distal humeral coronal shear fractures. The lateral extensile approach and fixation with countersunk headless compression screws placed in an anterior-to-posterior fashion are commonly used. We have found a two-incision approach (direct anterior and lateral) that results in less soft tissue dissection and better outcomes than the lateral extensile approach in our experience. Stiffness, pain, articular incongruity, arthritis, and ulnohumeral instability may result if reduction is non-anatomic or if fixation fails. PMID:25984515

  20. Contact mechanics of reverse engineered distal humeral hemiarthroplasty implants.

    PubMed

    Willing, Ryan; King, Graham J W; Johnson, James A

    2015-11-26

    Erosion of articular cartilage is a concern following distal humeral hemiarthroplasty, because native cartilage surfaces are placed in contact with stiff metallic implant components, which causes decreases in contact area and increases in contact stresses. Recently, reverse engineered implants have been proposed which are intended to promote more natural contact mechanics by reproducing the native bone or cartilage shape. In this study, finite element modeling is used in order to calculate changes in cartilage contact areas and stresses following distal humeral hemiarthroplasty with commercially available and reverse engineered implant designs. At the ulna, decreases in contact area were -34±3% (p=0.002), -27±1% (p<0.001) and -14±2% (p=0.008) using commercially available, bone reverse engineered and cartilage reverse engineered designs, respectively. Peak contact stresses increased by 461±57% (p=0.008), 387±127% (p=0.229) and 165±16% (p=0.003). At the radius, decreases in contact area were -21±3% (p=0.013), -13±2% (p<0.006) and -6±1% (p=0.020), and peak contact stresses increased by 75±52% (p>0.999), 241±32% (p=0.010) and 61±10% (p=0.021). Between the three different implant designs, the cartilage reverse engineered design yielded the largest contact areas and lowest contact stresses, but was still unable to reproduce the contact mechanics of the native joint. These findings align with a growing body of evidence indicating that although reverse engineered hemiarthroplasty implants can provide small improvements in contact mechanics when compared with commercially available designs, further optimization of shape and material properties is required in order reproduce native joint contact mechanics.

  1. Distal protection for treatment of complete cervical internal carotid occlusion.

    PubMed

    Hungerford, John P; Chaudry, Imran; Turner, Raymond; Turk, Aquilla S

    2012-01-01

    Distal protection devices (DPD) have been advocated for carotid artery stenting to reduce the risk of distal embolization. These devices were designed for deployment in the straight cervical segment of the internal carotid artery. We present a case of total cervical carotid occlusion recanalized with the aid of a distal protection device deployed 'distally' in the intracranial internal carotid artery.

  2. On Galaxy Mass-Radius Relationship

    NASA Astrophysics Data System (ADS)

    Bindoni, D.; Secco, L.; Contini, E.; Caimmi, R.

    In the Clausius' virial maximum theory (TCV) [Secco and Bindoni, NewA 14, 567 (2009)] to explain the galaxy Fundamental Plane (FP) a natural explanation follows about the observed relationship between stellar mass and effective radius, M ∗ - r e , for early type galaxies (ETGs). The key of this correlation lies in the deep link which has to exist between cosmology and the existence of the FP. The general strategy consists in using the two-component tensor virial theorem to describe the virial configuration of the baryonic component of mass M B ≃ M ∗ embedded in a dark matter (DM) halo of mass M D at the end of relaxation phase. In a ΛCDM flat cosmology, starting from variance at equivalence epoch, we derive some preliminary theoretical relationships, M ∗ - r e , which are functions of mass ratio m = M D / M B . They appear to be in agreement with the trends extracted from the data of galaxy sample used by [Tortora et al., MNRAS 396, 1132 (2009)].

  3. Photospheric Radius Expansion During Magnetar Bursts

    NASA Astrophysics Data System (ADS)

    Watts, Anna L.; Kouveliotou, Chryssa; van der Horst, Alexander J.; Göǧüş, Ersin; Kaneko, Yuki; van der Klis, Michiel; Wijers, Ralph A. M. J.; Harding, Alice K.; Baring, Matthew G.

    2010-08-01

    On 2008 August 24 the new magnetar SGR 0501+4516 (discovered by Swift) emitted a bright burst with a pronounced double-peaked structure in hard X-rays, reminiscent of the double-peaked temporal structure seen in some bright thermonuclear bursts on accreting neutron stars. In the latter case this is due to Photospheric Radius Expansion (PRE): when the flux reaches the Eddington limit, the photosphere expands and cools so that emission becomes softer and drops temporarily out of the X-ray band, re-appearing as the photosphere settles back down. We consider the factors necessary to generate double-peaked PRE events, and show that such a mechanism could plausibly operate in magnetar bursts despite the vastly different emission process. Identification of the magnetic Eddington limit in a magnetar would constrain magnetic field and distance and could, in principle, enable a measurement of gravitational redshift. It would also locate the emitting region at the neutron star surface, constraining the burst trigger mechanism. Conclusive confirmation of PRE events will require more detailed radiative models for bursts. However, for SGR 0501+4516 the predicted critical flux (using the magnetic field strength inferred from timing and the distance suggested by its probable location in the Perseus arm of our Galaxy) is consistent with that observed in the August 24 burst.

  4. Experimental study of finite Larmor radius effects

    SciTech Connect

    Struve, K.W.

    1980-08-01

    Linear Z-pinches in Ar, Kr, Xe, N/sub 2/, and He are experimentally studied in regimes where strong finite Larmor radius effects could provide a significant stabilizing effect. Scaling arguments show that for deuterium such a pinch has an electron line density of order 2 x 10/sup 15//cm. For higher Z plasmas a higher line density is allowed, the exact value of which depends on the average ion charge. The pinch is formed by puffing gas axially through the cathode towards the anode of an evacuated pinch chamber. When the gas reaches the anode, the pinch bank is fired. The pinch current rises in 2 to 3 ..mu..sec to a maximum of 100 to 200 kA. The pinch bank capacitance is 900 ..mu..F, and the external inductance is 100 nH. Additionally, the bank is fused to increase dI/dt. The primary diagnostics are a framing camera, a spatially resolved Mach-Zehnder interferometer, and X-ray absorption.

  5. Sextant of Sapphires for Molar Distalization

    PubMed Central

    Palla, Yudistar Venkata; Ganugapanta, Vivek Reddy

    2016-01-01

    Introduction Space analysis quantifies the amount of crowding within the arches estimating the severity of space discrepancy. The space gaining procedures include extraction and non-extraction procedures like expansion, proximal stripping and molar distalization. Aim To identify features seen in molar distalization cases. Materials and Methods The sample size comprised 20 patients in whom molar distalization was decided as the treatment plan. The study models and lateral cephalograms of all the patients were taken. Occlusograms were obtained. Model analysis and cephalometric analysis were performed. Descriptive statistical analysis like mean, standard deviation, standard error and mode were done. Results The parameters in Question gave following results. The Bolton analysis showed anterior mandibular excess with mean value of 1.56mm±1.07. The first order discrepancy between maxillary central and lateral incisors was 5±1.95. The premolar rotation showed mean value of 16.58±5.12. The molar rotation showed the value of 7.66±2.26. The nasolabial angle showed the mean of 101.25±8.7 IMPA of 101.4±5.74. Conclusion The six features studied in molar distalization cases [First order discrepancy between upper central and lateral incisors; Rotation of premolars and molars; Bolton’s discrepancy in anterior dentition; Average to horizontal growth pattern; Proclined lower incisors and Obtuse nasolabial angle] can be taken as patterns seen in molar distalization cases and considered as a valid treatment plan. PMID:27656572

  6. Failure of distal biceps repair by gapping

    PubMed Central

    Copas, David; Watts, Adam C

    2016-01-01

    Background We describe the clinical, radiological and surgical findings of failed distal biceps repair by gapping and report the functional outcomes following revision repair. Methods A retrospective review of five consecutive patients was conducted. Patients presented with radial-sided forearm pain after their distal biceps fixation. All patients had less than 5 cm of retraction of the biceps muscle belly, a palpable tendon although the manoeuvre was painful with weakness on resisted supination. Flexed abducted supinated magnetic resonance imaging (FABS MRI) showed a gap between the distal end of the tendon and the footprint on the radial tuberosity. Results Mean FEA score at presentation was 44/100 (35 to 49). Mean time to re-operation was 18 months (range 4 months to 36 months). At revision, the distal end of the tendon was retracted and not making contact with the bone. All cases were revised to an in-bone endobutton repair. Mean postoperative Functional Elbow Assessment (FEA) scores undertaken at a mean of 14 months (range 5 months to 22 months) after revision improved to 95/100 (90 to 100). Conclusions Patients presenting with persistent radial sided forearm pain and weakness on provocative testing after distal biceps repair with a seemingly intact repair should be investigated with FABS MRI to look for evidence of failure of repair by gapping. Revision repair with an anatomic in-bone technique can lead to good results. PMID:27583018

  7. Fabrication and Evaluation of a Noncompliant Molar Distalizing Appliance: Bonded Molar Distalizer

    PubMed Central

    Sodagar, A.; Ahmad Akhoundi, M. S.; Rafighii, A.; Arab, S.

    2011-01-01

    Objective Attempts to treat class II malocclusions without extraction in non-compliant patients have led to utilization of intraoral molar distalizing appliances. The purpose of this study was to investigate dental and skeletal effects of Bonded Molar Distalizer (BMD) which is a simple molar distalizing appliance. Materials and Methods Sixteen patients (12 girls, four boys) with bilateral half-cusp class II molar relationship, erupted permanent second molars and normal or vertical growth pattern were selected for bilateral distalization of maxillary molars via BMD. The screws were activated every other day, alternately. Lateral cephalograms and study models were obtained before treatment and after 11 weeks activation of the appliance. Results Significant amounts of molar distalization, molar distal tipping and anchorage loss were observed. The mean maxillary first molar distal movement was 1.22±0.936 mm with a distal tipping of 2.97±3.74 degrees in 11 weeks. The rate of distal movement was 0.48 mm per month. Reciprocal mesial movement of the first premolars was 2.26±1.12 mm with a mesial tipping of 4.25±3.12 degrees. Maxillary incisors moved 3.55±1.46 mm and tipped 9.87±5.03 degrees mesially. Lower anterior face height (LAFH) decreased 1.28±1.36 mm. Conclusion BMD is appropriate for distalizing maxillary molars, especially in patients with critical LAFH, although significant amounts of anchorage loss occur using this appliance. PMID:22457837

  8. Treatment Options for Distal Femur Fractures.

    PubMed

    von Keudell, Arvind; Shoji, Kristin; Nasr, Michael; Lucas, Robert; Dolan, Robert; Weaver, Michael J

    2016-08-01

    Despite advances in implant design, the management of distal femur fractures remains challenging. Fracture comminution and intra-articular extension can make it difficult to obtain an adequate reduction while preserving the soft tissue attachments to bone fragments to allow for bone healing. Many implant manufacturers have developed optimal anatomically contoured, distal femoral locking plates with percutaneous guides. This environment allows for the application of lateral locked plates in a biologically friendly manner. Although initial reports had high success rates, more recently a high rate of nonunion has been found, particularly in elderly patients. Limited literature is available for the treatment of patients with osteoporotic bone and associated ipsilateral total knee replacement and hip replacement. We present a patient with a distal femur fracture with significant comminution in the setting of an ipsilateral total hip replacement. PMID:27441931

  9. Computational finite element bone mechanics accurately predicts mechanical competence in the human radius of an elderly population.

    PubMed

    Mueller, Thomas L; Christen, David; Sandercott, Steve; Boyd, Steven K; van Rietbergen, Bert; Eckstein, Felix; Lochmüller, Eva-Maria; Müller, Ralph; van Lenthe, G Harry

    2011-06-01

    High-resolution peripheral quantitative computed tomography (HR-pQCT) is clinically available today and provides a non-invasive measure of 3D bone geometry and micro-architecture with unprecedented detail. In combination with microarchitectural finite element (μFE) models it can be used to determine bone strength using a strain-based failure criterion. Yet, images from only a relatively small part of the radius are acquired and it is not known whether the region recommended for clinical measurements does predict forearm fracture load best. Furthermore, it is questionable whether the currently used failure criterion is optimal because of improvements in image resolution, changes in the clinically measured volume of interest, and because the failure criterion depends on the amount of bone present. Hence, we hypothesized that bone strength estimates would improve by measuring a region closer to the subchondral plate, and by defining a failure criterion that would be independent of the measured volume of interest. To answer our hypotheses, 20% of the distal forearm length from 100 cadaveric but intact human forearms was measured using HR-pQCT. μFE bone strength was analyzed for different subvolumes, as well as for the entire 20% of the distal radius length. Specifically, failure criteria were developed that provided accurate estimates of bone strength as assessed experimentally. It was shown that distal volumes were better in predicting bone strength than more proximal ones. Clinically speaking, this would argue to move the volume of interest for the HR-pQCT measurements even more distally than currently recommended by the manufacturer. Furthermore, new parameter settings using the strain-based failure criterion are presented providing better accuracy for bone strength estimates.

  10. Distal Humerus Fractures: Open Reduction Internal Fixation.

    PubMed

    Mighell, Mark A; Stephens, Brent; Stone, Geoffrey P; Cottrell, Benjamin J

    2015-11-01

    Distal humerus fractures are challenging injuries for the upper extremity surgeon. However, recent techniques in open reduction internal fixation have been powerful tools in getting positive outcomes. To get such results, the surgeon must be aware of how to properly use these techniques in their respective practices. The method of fixation depends on the fracture, taking the degree of comminution and the restoration of the columns and articular surface into account. This article helps surgeons understand the concepts behind open reduction internal fixation of the distal humerus and makes them aware of pitfalls that may lead to negative results.

  11. Comparison of Maxillary Molar Distalization with an Implant-Supported Distal Jet and a Traditional Tooth-Supported Distal Jet Appliance

    PubMed Central

    Cozzani, Mauro; Pasini, Marco; Zallio, Francesco; Ritucci, Robert; Mutinelli, Sabrina; Mazzotta, Laura; Giuca, Maria Rita; Piras, Vincenzo

    2014-01-01

    Aim. To investigate and compare the efficiency of two appliances for molar distalization: the bone-anchored distal screw (DS) and the traditional tooth-supported distal jet (DJ) for molar distalization and anchorage loss. Methods. Tests (18 subjects) were treated with a DS and controls (18 subjects) were treated with a DJ. Lateral cephalograms were obtained before and at the end of molar distalization and were analysed. Shapiro Wilk test, unpaired t-test, and Wilcoxon rank-sum test were applied according to values distribution. The α level was fixed at 0.05. Results. Maxillary first molars were successfully distalized into a Class I relationship in all patients. The mean molar distalization and treatment time were similar in both groups. The DS group exhibited a spontaneous distalization (2.1 ± 0.9 mm) of the first premolar with control of anchorage loss, distal tipping, extrusion, and skeletal changes. Conclusions. The DS is an adequate compliance-free distalizing appliance that can be used safely for the correction of Class II malocclusions. In comparison to the traditional DJ, the DS enables not only a good rate of molar distalization, but also a spontaneous distalization of the first premolars. PMID:25018770

  12. Comparative evaluation of molar distalization therapy using pendulum and distal screw appliances

    PubMed Central

    Cafagna, Alessandra; Fontana, Mattia; Cozzani, Mauro

    2015-01-01

    Objective To compare dentoalveolar and skeletal changes produced by the pendulum appliance (PA) and the distal screw appliance (DS) in Class II patients. Methods Forty-three patients (19 men, 24 women) with Class II malocclusion were retrospectively selected for the study. Twenty-four patients (mean age, 12.2 ± 1.5 years) were treated with the PA, and 19 patients (mean age, 11.3 ± 1.9 years) were treated with the DS. The mean distalization time was 7 months for the PA group and 9 months for the DS group. Lateral cephalograms were obtained at T1, before treatment, and at T2, the end of distalization. A Mann-Whitney U test was used for statistical comparisons of the two groups between T1 and T2. Results PA and DS were equally effective in distalizing maxillary molars (4.7 mm and 4.2 mm, respectively) between T1 and T2; however, the maxillary first molars showed less distal tipping in the DS group than in the PA group (3.2° vs. 9.0°, respectively). Moreover, significant premolar anchorage loss (2.7 mm) and incisor proclination (5.0°) were noted in the PA group, whereas premolar distal movement (1.9 mm) and no significant changes at the incisor (0.1°) were observed in the DS group. No significant sagittal or vertical skeletal changes were detected between the two groups during the distalization phase. Conclusions PA and DS seem to be equally effective in distalizing maxillary molars; however, greater distal molar tipping and premolar anchorage loss can be expected using PA. PMID:26258063

  13. Discharge coefficients of cooling holes with radiused and chamfered inlets

    NASA Astrophysics Data System (ADS)

    Hay, N.; Spencer, A.

    1991-06-01

    The flow of cooling air within the internal passages of gas turbines is controlled and metered using holes in disks and casings. The effects of inlet radiusing and chamfering of these holes on the discharge coefficient are discussed. Experimental results for a range of radiusing and chamfering ratios for holes of different length to diameter ratios are presented, covering the range of pressure ratios of practical interest. The results indicate that radiusing and chamfering are both beneficial in increasing the discharge coefficient. Increases of 10-30 percent are possible. Chamfered holes give the more desirable performance characteristics in addition to being easier to produce than radiused holes.

  14. Improving optical bench radius measurements using stage error motion data

    SciTech Connect

    Schmitz, Tony L.; Gardner, Neil; Vaughn, Matthew; Medicus, Kate; Davies, Angela

    2008-12-20

    We describe the application of a vector-based radius approach to optical bench radius measurements in the presence of imperfect stage motions. In this approach, the radius is defined using a vector equation and homogeneous transformation matrix formulism. This is in contrast to the typical technique, where the displacement between the confocal and cat's eye null positions alone is used to determine the test optic radius. An important aspect of the vector-based radius definition is the intrinsic correction for measurement biases, such as straightness errors in the stage motion and cosine misalignment between the stage and displacement gauge axis, which lead to an artificially small radius value if the traditional approach is employed. Measurement techniques and results are provided for the stage error motions, which are then combined with the setup geometry through the analysis to determine the radius of curvature for a spherical artifact. Comparisons are shown between the new vector-based radius calculation, traditional radius computation, and a low uncertainty mechanical measurement. Additionally, the measurement uncertainty for the vector-based approach is determined using Monte Carlo simulation and compared to experimental results.

  15. Preliminary evaluation of robotic needle distal tip repositioning

    NASA Astrophysics Data System (ADS)

    Walsh, Conor J.; Slocum, Alexander H.; Gupta, Rajiv

    2011-03-01

    Advances in medical imaging now provide detailed images of solid tumors inside the body and miniaturized energy delivery systems enable tumor destruction through local heating powered by a thin electrode. We have developed a robot for accurately repositioning the distal tip of a medical instrument such an ablation probe to adjacent points within tissue. The position accuracy in ballistics gelatin was evaluated in a 2D experimental setup with a digital SLR camera that was fixed to a rig that also contained the gelatin. The robot was mounted to the rig in such a way that the stylet was deployed in a plane parallel the camera's lens. A grid paper attached to the back of the box containing the gelatin provided a stationary reference point for each of the pictures taken and also served as a coordinate system for making measurements. The measurement repeatability error was found by taking a stylet tip position measurement five times for two different pictures and found to be 0.26 mm. For a stylet with a radius of curvature of 31.5 mm and a diameter of 0.838 mm, the targeting accuracy was found to be 2.5 +/- 1.4 mm at points that were approximately 38 mm lateral from the cannula axis.

  16. Measurement of humerus and radius bone mineral content in the term and preterm infant

    SciTech Connect

    Vyhmeister, N.R.; Linkhart, T.A.

    1988-07-01

    We compared two anatomic sites for single-photon absorptiometric measurement of bone mineral content (BMC) in term and preterm infants. The distal one third of the radius and the midportion of the humerus were evaluated for measurements of BMC with an unmodified, commercially available bone densitometer. We assessed reproducibility of BMC and bone width (BW) measurements and defined normal at-birth ranges of BMC, BW, and BMC/BW ratio for infants with gestational ages of 24 to 42 weeks. Humerus BMC correlated with gestational age, birth weight, and BW of patients and did not differ from humerus BMC values determined over the same range of gestational ages at another center. Representative serial measurements of two very low birth weight (VLBW) infants are presented to demonstrate the feasibility of using humerus BMC in longitudinal studies to assess changes in bone mineralization. We conclude that bone densitometer measurements of mid-humerus BMC can be successfully performed and are preferable to similar measurements of the radius for VLBW infants. Normal humerus BMC values were defined for use in diagnosis and evaluation of the efficacy of treatment in VLBW infants who are at high risk of developing osteopenia of prematurity.

  17. The Origin of the Ionic-Radius Ratio Rules

    ERIC Educational Resources Information Center

    Jensen, William B.

    2010-01-01

    In response to a reader query, this article traces the origins of the ionic-radius ratio rules and their incorrect attribution to Linus Pauling in the chemical literature and to Victor Goldschmidt in the geochemical literature. In actual fact, the ionic-radius ratio rules were first proposed within the context of the coordination chemistry…

  18. [Effect of ski tapering on turning radius and stress].

    PubMed

    Mössner, M; Nachbauer, W; Schindelwig, K

    1997-12-01

    The first part of this paper deals with the influence of the side cut on the turn radius, which was examined by measuring the turn radius of a self-running sledge-like construction and by comparing it to Howe's prediction. The turn radius at the beginning of the turn has proved to be between 65 and 85% of the theoretically expected result. In the second part a carvers turn radius was determined and the reaction force acting on the skier was calculated. The result shows a strong reduction of the turn radius along the path which increases the load on the skier. The effect of side cut and velocity on the load was examined. Using carver skis even small changes in velocity resulted in considerable load changes.

  19. Genetics Home Reference: distal hereditary motor neuropathy, type II

    MedlinePlus

    ... hereditary motor neuropathy, type II distal hereditary motor neuropathy, type II Enable Javascript to view the expand/ ... Open All Close All Description Distal hereditary motor neuropathy, type II is a progressive disorder that affects ...

  20. Genetics Home Reference: distal hereditary motor neuropathy, type V

    MedlinePlus

    ... hereditary motor neuropathy, type V distal hereditary motor neuropathy, type V Enable Javascript to view the expand/ ... Open All Close All Description Distal hereditary motor neuropathy, type V is a progressive disorder that affects ...

  1. Thrombocytopenia with Unilateral Dysplastic Radius- Is it Thrombocytopenia - Absent Radius (TAR) Syndrome?

    PubMed

    Kumar, Mani Kant; Chaudhary, Indradeo Prasad; Ranjan, Ram Bilas; Kumar, Prashant

    2015-03-01

    Thrombocytopenia - absent radii (TAR) syndrome is an autosomal recessive genetic rare disorder with hypomegakaryocytic thrombocytopenia and bilateral absent radius that may have additional anomalies. This disorder is characterized by thrombocytopenia resulting in potentially severe bleeding episodes primarily during infancy. We report the case of a 7-day-old term appropriate for gestational age (AGA) male baby, product of non consanguineous marriage presented with bloody loose stool, right sided upper limb deformity and paleness of the body, was diagnosed as TAR syndrome with some atypical presentation. Such type of atypical presentation has not been previously reported in a case with TAR Syndrome.Patient was managed in our hospital with packed cell transfusion and two units platelets concentrates transfusion, Intra-venous antimicrobials, and other supportive treatment. He gradually improved and was discharged after seven days of hospital stay with advice to consult orthopedic surgeon for opinion regarding limb reconstruction. PMID:25954675

  2. Extracorporeal shockwave lithotripsy of distal ureteral calculi.

    PubMed

    Miller, K; Bubeck, J R; Hautmann, R

    1986-01-01

    To date, the use of extracorporeal shockwave lithotripsy (ESWL) has been limited to renal calculi and ureteral calculi above the pelvic brim. Modifying the position of the patient on the support of the Dornier lithotripter HM3, we were able to localize and treat distal ureteral calculi. Until April 1986, 43 patients with stones in the lower ureter underwent contact-free lithotripsy. Treatment was successful in 39 patients (90%), 2 of these requiring 2 sessions. In 4 patients treatment failed and stone removal was accomplished using ureteroscopy or open surgery. No complications or adverse side effects were encountered in the whole series. ESWL is now the method of choice for the treatment of distal ureteral calculi in our department.

  3. Fracture of distal end clavicle: A review

    PubMed Central

    Sambandam, Balaji; Gupta, Rajat; Kumar, Santosh; Maini, Lalit

    2014-01-01

    Management of fracture distal end clavicle has always puzzled the orthopaedic surgeons. Now-a-days with a relatively active lifestyle, patients want better results both cosmetically and functionally. Despite so much literature available for the management of this common fracture, there is no consensus regarding the gold standard treatment for this fracture. In this article, we reviewed the literature on various techniques of management for this fracture, both conservative as well as surgical, and their merits and demerits. PMID:25983473

  4. Distal Embolic Protection for Renal Arterial Interventions

    SciTech Connect

    Dubel, Gregory J. Murphy, Timothy P.

    2008-01-15

    Distal or embolic protection has intuitive appeal for its potential to prevent embolization of materials generated during interventional procedures. Distal protection devices (DPDs) have been most widely used in the coronary and carotid vascular beds, where they have demonstrated the ability to trap embolic materials and, in some cases, to reduce complications. Given the frequency of chronic kidney disease in patients with renal artery stenosis undergoing stent placement, it is reasonable to propose that these devices may play an important role in limiting distal embolization in the renal vasculature. Careful review of the literature reveals that atheroembolization does occur during renal arterial interventions, although it often goes undetected. Early experience with DPDs in the renal arteries in patients with suitable anatomy suggests retrieval of embolic materials in approximately 71% of cases and renal functional improvement/stabilization in 98% of cases. The combination of platelet inhibition and a DPD may provide even greater benefit. Given the critical importance of renal functional preservation, it follows that everything that can be done to prevent atheroembolism should be undertaken including the use of DPDs when anatomically feasible. The data available at this time support a beneficial role for these devices.

  5. Distal nerve entrapment following nerve repair.

    PubMed

    Schoeller, T; Otto, A; Wechselberger, G; Pommer, B; Papp, C

    1998-04-01

    Failure of nerve repair or poor functional outcome after reconstruction can be influenced by various causes. Besides improper microsurgical technique, fascicular malalignment and unphysiologic tension, we found in our clinical series that a subclinical nerve compression distal to the repair site can seriously impair regeneration. We concluded that the injured nerve, whether from trauma or microsurgical intervention, could be more susceptible to distal entrapment in the regenerative stage because of its disturbed microcirculation, swelling and the increase of regenerating axons followed by increased nerve volume. In two cases we found the regenerating nerve entrapped at pre-existing anatomical sites of narrowing resulting in impaired functional recovery. In both cases the surgical therapy was decompression of the distal entrapped nerve and this was followed by continued regeneration. Thorough clinical and electrophysiologic follow-up is necessary to detect such adverse compression effects and to distinguish between the various causes of failed regeneration. Under certain circumstances primary preventive decompression may be beneficial if performed at the time of nerve coaptation.

  6. Mirrored visual feedback limits distal effect anticipation.

    PubMed

    Sutter, Christine; Ladwig, Stefan

    2012-04-01

    Modern tools in technological environments are often characterized by a spatial separation of hand actions (operating a remote control) and their intended action effects (displayed movements of an unmanned vehicle, a robot, or an avatar on a screen). Often non-corresponding proximal and distal movement effects put high demands on the human information processing system. The present study aimed to investigate how modern technological environments influence processes of planning and controlling actions. Participants performed ipsi- or contralateral movements in response to colored stimuli, while the stimulus location had to be ignored. They did not see the stimuli and hands directly, but received visual feedback (with retained or reversed spatial relations) on a projection screen in front of them. Visual feedback retaining spatial relations led to the usual Simon effect. However, visual feedback reversing spatial relations inverted the Simon effect in ipsilateral responses, and eliminated it in contralateral responses (Exp. 1). Impairing the proximal movement-effect loop so that proprioceptive/tactile information from the moving hand was no longer a reliable source for planning and controlling actions attenuated compatibility effects (Exp. 2). Moreover, distal action effects predominated action control even for opposing body-related effects. It seemed that action control of transformed movements depended on the reliability of proprioceptive/tactile and visual information. When the amount of feature overlap between proprioception and vision was low and proprioceptive (visual) information was no longer reliable, then distal (proximal) action effects stepped forward and became crucial in controlling transformed actions.

  7. ON THE VARIATION OF SOLAR RADIUS IN ROTATION CYCLES

    SciTech Connect

    Qu, Z. N.; Kong, D. F.; Xiang, N. B.; Feng, W.

    2015-01-10

    The Date Compensated Discrete Fourier Transform and CLEANest algorithm are used to study the temporal variations of the solar radius observed at Rio de Janeiro Observatory from 1998 March 2 to 2009 November 6. The CLEANest spectra show several significant periodicities around 400, 312, 93.5, 86.2, 79.4, 70.9, 53.2, and 26.3 days. Then, combining the data on the daily solar radius measured at Calern Observatory and Rio de Janeiro Observatory and the corresponding daily sunspot areas, we study the short-term periodicity of the solar radius and the role of magnetic field in the variation of the solar radius. The rotation period of the daily solar radius is determined to be statistically significant. Moreover, its temporal evolution is anti-phase with that of sunspot activity, and it is found anti-phase with solar activity. Generally, the stronger solar activity is, the more obvious is the anti-phase relation of radius with solar activity. This indicates that strong magnetic fields have a greater inhibitive effect than weak magnetic fields on the variation of the radius.

  8. Finite Larmor radius modification of the Mercier criterion

    SciTech Connect

    Connor, J.W.; Tang, W.M.; Allen, L.

    1984-04-01

    The finite Larmor radius modification of the Suydam criterion involves a competition between stabilizing finite Larmor radius effects and destabilizing curvature. In the case of the toroidal calculation, corresponding to the Mercier criterion, ballooning effects from regions of unfavorable curvature must be taken into account. In the case of a model equilibrium, valid near the magnetic axis, a complete solution is obtained. Results indicate that the amount of finite Larmor radius stabilization needed to overcome the effects of unfavorable average curvature increases as a function of the toroidal ballooning parameter.

  9. Study of a non-intrusive electron beam radius diagnostic

    SciTech Connect

    Kwan, T.J.T.; DeVolder, B.G.; Goldstein, J.C.; Snell, C.M.

    1997-12-01

    The authors have evaluated the usefulness and limitation of a non-intrusive beam radius diagnostic which is based on the measurement of the magnetic moment of a high-current electron beam in an axisymmetric focusing magnetic field, and relates the beam root-mean-square (RMS) radius to the change in magnetic flux through a diamagnetic loop encircling the beam. An analytic formula that gives the RMS radius of the electron beam at a given axial position and a given time is derived and compared with results from a 2-D particle-in-cell code. The study has established criteria for its validity and optimal applications.

  10. Robotic distal pancreatectomy versus conventional laparoscopic distal pancreatectomy: a comparative study for short-term outcomes.

    PubMed

    Lai, Eric C H; Tang, Chung Ngai

    2015-09-01

    Robotic system has been increasingly used in pancreatectomy. However, the effectiveness of this method remains uncertain. This study compared the surgical outcomes between robot-assisted laparoscopic distal pancreatectomy and conventional laparoscopic distal pancreatectomy. During a 15-year period, 35 patients underwent minimally invasive approach of distal pancreatectomy in our center. Seventeen of these patients had robot-assisted laparoscopic approach, and the remaining 18 had conventional laparoscopic approach. Their operative parameters and perioperative outcomes were analyzed retrospectively in a prospective database. The mean operating time in the robotic group (221.4 min) was significantly longer than that in the laparoscopic group (173.6 min) (P = 0.026). Both robotic and conventional laparoscopic groups presented no significant difference in spleen-preservation rate (52.9% vs. 38.9%) (P = 0.505), operative blood loss (100.3 ml vs. 268.3 ml) (P = 0.29), overall morbidity rate (47.1% vs. 38.9%) (P = 0.73), and post-operative hospital stay (11.4 days vs. 14.2 days) (P = 0.46). Both groups also showed no perioperative mortality. Similar outcomes were observed in robotic distal pancreatectomy and conventional laparoscopic approach. However, robotic approach tended to have the advantages of less blood loss and shorter hospital stay. Further studies are necessary to determine the clinical position of robotic distal pancreatectomy.

  11. Experiments towards resolving the proton charge radius puzzle

    NASA Astrophysics Data System (ADS)

    Antognini, A.; Schuhmann, K.; Amaro, F. D.; Amaro, P.; Abdou-Ahmed, M.; Biraben, F.; Chen, T.-L.; Covita, D. S.; Dax, A. J.; Diepold, M.; Fernandes, L. M. P.; Franke, B.; Galtier, S.; Gouvea, A. L.; Götzfried, J.; Graf, T.; Hänsch, T. W.; Hildebrandt, M.; Indelicato, P.; Julien, L.; Kirch, K.; Knecht, A.; Kottmann, F.; Krauth, J. J.; Liu, Y.-W.; Machado, J.; Monteiro, C. M. B.; Mulhauser, F.; Nez, F.; Santos, J. P.; dos Santos, J. M. F.; Szabo, C. I.; Taqqu, D.; Veloso, J. F. C. A.; Voss, A.; Weichelt, B.; Pohl, R.

    2016-03-01

    We review the status of the proton charge radius puzzle. Emphasis is given to the various experiments initiated to resolve the conflict between the muonic hydrogen results and the results from scattering and regular hydrogen spectroscopy.

  12. Laser differential confocal radius measurement method for the cylindrical surfaces.

    PubMed

    Qiu, Lirong; Xiao, Yang; Zhao, Weiqian

    2016-05-30

    This paper proposes a laser differential confocal cylindrical radius of curvature measurement (DCCRM) method for high accuracy measurement of the radius of curvature of the cylindrical lens. Based on the property that the null point of an axial intensity curve precisely corresponds to the focus of the objective in a differential confocal system (DCS), the DCCRM uses the null point of the DCS axial intensity curve to precisely identify the cat's eye position and confocal position of the test cylindrical lens. The distance between the two positions is measured accurately using a laser distance instrument, thus achieving high precision radius measurement. In comparison with existing measurement methods, the proposed DCCRM has high measurement precision and strong environmental anti-interference capability. Theoretical analyses and preliminary experimental results indicate that the DCCRM has a relative measurement uncertainty of better than 0.03% and provides a new approach for a high precision radius measurement of the cylindrical lens.

  13. LONG-TERM PERIODICITY VARIATIONS OF THE SOLAR RADIUS

    SciTech Connect

    Qu, Z. N.; Xie, J. L.

    2013-01-01

    In order to study the long-term periodicity variations of the solar radius, daily solar radius data from 1978 February to 2000 September at the Calern Observatory are used. Continuous observations of the solar radius are difficult due to the weather, seasonal effects, and instrument characteristics. Thus, to analyze these data, we first use the Dixon criterion to reject suspect values, then we measure the cross-correlation between the solar radius and sunspot numbers. The result indicates that the solar radius is in complete antiphase with the sunspot numbers and shows lead times of 74 months relative to the sunspot numbers. The Lomb-Scargle and date compensated discrete Fourier transform methods are also used to investigate the periodicity of the solar radius. Both methods yield similar significance periodicities around {approx}1 yr, {approx}2.6 yr, {approx}3.6 yr, and {approx}11 yr. Possible mechanisms for these periods are discussed. The possible physical cause of the {approx}11 yr period is the cyclic variation of the magnetic pressure of the concentrated flux tubes at the bottom of the solar convection zone.

  14. Impact of Radius Malunion on Wrist Contact Mechanics.

    PubMed

    Lalone, Emily A; Grewal, Ruby; MacDermid, Joy C

    2016-05-01

    The patient was a 15-year-old adolescent girl with a chief complaint of intermittent pain and clicking at her right distal radioulnar joint, after having fractured her forearm 5 months previously. Radiographs of the patient's forearm indicated a midshaft radial deformity. Given the patient's pain and limited range of motion, computed tomography imaging was requested to assess whether the midshaft malunion resulted in distal radioulnar joint instability and to plan the corrective osteotomy. J Orthop Sports Phys Ther 2016;46(5):399. doi:10.2519/jospt.2016.0406. PMID:27133942

  15. Complications of Distal Biceps Tendon Repair

    PubMed Central

    Amin, Nirav H.; Volpi, Alex; Lynch, T. Sean; Patel, Ronak M.; Cerynik, Douglas L.; Schickendantz, Mark S.; Jones, Morgan H.

    2016-01-01

    Background: Anatomic reinsertion of the distal biceps is critical for restoring flexion and supination strength. Single- and double-incision surgical techniques have been reported, analyzing complications and outcomes measures. Which technique results in superior clinical outcomes and the lowest associated complications remains unclear. Hypothesis: We hypothesized that rerupture rates would be similar between the 2 techniques, while nerve complications would be higher for the single-incision technique and heterotopic ossification would be more frequent with the double-incision technique. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: A systematic review was conducted using the PubMed, MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), SPORTSDiscus, and the Cochrane Central Register of Controlled Trials databases to identify articles reporting distal biceps ruptures up to August 2013. We included English-language articles on adult patients with a minimum of 3 cases reporting single- and double-incision techniques. Frequencies of each complication as a percentage of total cases were calculated. Fisher exact tests were used to test the association between frequencies for each repair method, with P < .05 considered statistically significant. Odds ratios with 95% CIs were also computed. Results: A total of 87 articles met the inclusion criteria. Lateral antebrachial cutaneous nerve neurapraxia was the most common complication in the single-incision group, occurring in 77 of 785 cases (9.8%). Heterotopic ossification was the most common complication in the double-incision group, occurring in 36 of 498 cases (7.2%). Conclusion: The overall frequency of reported complications is higher for single-incision distal biceps repair than for double-incision repair. The frequencies of rerupture and nerve complications are both higher for single-incision repairs while the frequency of heterotopic ossification is higher for

  16. Distal Renal Tubular Acidosis and Calcium Nephrolithiasis

    NASA Astrophysics Data System (ADS)

    Moe, Orson W.; Fuster, Daniel G.; Xie, Xiao-Song

    2008-09-01

    Calcium stones are commonly encountered in patients with congenital distal renal tubular acidosis, a disease of renal acidification caused by mutations in either the vacuolar H+-ATPase (B1 or a4 subunit), anion exchanger-1, or carbonic anhydrase II. Based on the existing database, we present two hypotheses. First, heterozygotes with mutations in B1 subunit of H+-ATPase are not normal but may harbor biochemical abnormalities such as renal acidification defects, hypercalciuria, and hypocitraturia which can predispose them to kidney stone formation. Second, we propose at least two mechanisms by which mutant B1 subunit can impair H+-ATPase: defective pump assembly and defective pump activity.

  17. Relay NBS Graft with the Plus Delivery System to Improve Deployment in Aortic Arch with Small Radius Curve

    SciTech Connect

    Ferro, Carlo; Rossi, Umberto G. Seitun, Sara; Guastavino, Andrea; Scarano, Flavio; Passerone, Gian Carlo

    2011-04-15

    The purpose of this report is to describe deployment of the Relay NBS Thoracic Stent Graft with the Plus Delivery System (Bolton Medical, Sunrise, FL) in a flexible resin arch model with a 15-mm radius curve as well as our preliminary clinical results. The Relay NBS graft with the Plus Delivery System was evaluated by way of bench testing, which was performed with stent grafts with diameters ranging from 24 to 46 mm and lengths ranging from 100 to 250 mm in flexible resin arch models with a 15-mm arch radius of curvature. The deployment sequence was analyzed. The Relay NBS graft with the Plus Delivery System was deployed in two patients, respectively, having a 6.5-cm penetrating aortic ulcer of the proximal third of the descending thoracic aorta and a DeBakey type-I aortic dissection with chronic false lumen dilatation after surgery due to an entry site at the distal thoracic aorta. Bench tests showed proper conformation and apposition of the Relay NBS graft with the Plus Delivery System in the flexible resin model. This stent graft was deployed successfully into the two patients with a correct orientation of the first stent and without early or late complications. The Relay NBS graft with the Plus Delivery System ensures an optimal conformation and apposition of the first stent in the aortic arch with a small radius of curvature.

  18. Aqueous outflow: Segmental and distal flow

    PubMed Central

    Swaminathan, Swarup S.; Oh, Dong-Jin; Kang, Min Hyung; Rhee, Douglas J.

    2014-01-01

    A prominent risk factor of primary open-angle glaucoma is ocular hypertension, a pathologic state caused by impaired outflow of aqueous humor through the trabecular meshwork within the iridocorneal angle. The juxtacanalicular region of the trabecular meshwork and the inner wall of Schlemm canal have been identified as the main contributors to aqueous outflow resistance, and both extracellular matrix within the trabecular meshwork and trabecular meshwork cell shape have been shown to affect outflow. Overexpression of multiple ECM proteins in perfused cadaveric human eyes has led to increased outflow resistance and elevated IOP. Pharmacologic agents targeting trabecular meshwork cytoskeletal arrangements have been developed after multiple studies demonstrated the importance of cell shape on outflow. Several groups have shown that aqueous outflow occurs only at certain segments of the trabecular meshwork circumferentially, a concept known as segmental flow. This is based on the theory that aqueous outflow is dependent on the presence of discrete pores within the Schlemm canal. Segmental flow has been described in the eyes of multiple species, including primate, bovine, mouse, and human samples. While the trabecular meshwork appears to be the major source of resistance, trabecular meshwork bypass procedures have been unable to achieve the degree of IOP reduction observed with trabeculectomy, reflecting the potential impact of distal flow, or flow through Schlemm canal and collector channels, on outflow. Multiple studies have demonstrated that outflow occurs preferentially near collector channels, suggesting that these distal structures may be more important to aqueous outflow than previously believed. PMID:25088623

  19. Maxillary molar distalization with first class appliance

    PubMed Central

    Ramesh, Namitha; Palukunnu, Biswas; Ravindran, Nidhi; Nair, Preeti P

    2014-01-01

    Non-extraction treatment has gained popularity for corrections of mild-to-moderate class II malocclusion over the past few decades. The distalization of maxillary molars is of significant value for treatment of cases with minimal arch discrepancy and mild class II molar relation associated with a normal mandibular arch and acceptable profile. This paper describes our experience with a 16-year-old female patient who reported with irregularly placed upper front teeth and unpleasant smile. The patient was diagnosed to have angles class II malocclusion with moderate maxillary anterior crowding, deep bite of 4 mm on a skeletal class II base with an orthognathic maxilla and retrognathic mandible and normal growth pattern. She presented an ideal profile and so molar distalization was planned with the first-class appliance. Molars were distalised by 8 mm on the right and left quadrants and class I molar relation achieved within 4 months. The space gained was utilised effectively to align the arch and establish a class I molar and canine relation. PMID:24577171

  20. Distal metatarsal coalition: A rare case report

    PubMed Central

    Vun, Shen Hwa; Drampalos, Efstathios; Shareef, Sajan; Sinha, Satyajit; Bramley, Diane

    2015-01-01

    Introduction Metatarsal coalition is an extremely rare condition. We report the second documented case of 4th and 5th distal metatarsal coalition in the literature. Presentation of case An eight-year-old girl was referred to an orthopaedic clinic with a four-month history of forefoot pain and swelling on the plantar aspect of the right little toe. Radiograph and clinical examination confirmed distal metatarsal coalition between the 4th and 5th metatarsals. Following a period of conservative treatment, excision was eventually performed due to worsening symptoms. Patient re-attended two years later with a recurrence of the coalition confirmed by computed tomography (CT) scan. The case was discussed at a tertiary paediatric orthopaedic insititution. Decision was made to manage patient conservatively with insole and physiotherapy until skeletal maturity. A year later, patient’s symptoms did not worsen, and her foot displayed no evidence of change in the arch and shape. Discussion The timing of ossification of coalition varies from one anatomical site to another. Surgery when performed before ossification is complete runs the risk of recurrence. Conclusion Our case report illustrates the importance of restoring normal weight bearing dynamics and pain relief when managing metatarsal coalition, or synostosis in skeletally immature patients. We recommend persevering with conservative treatment, with operative treatment reserved only as a later option, and ideally, until skeletal maturity is achieved. PMID:25670408

  1. Distal vacuolar myopathy in nephropathic cystinosis.

    PubMed

    Charnas, L R; Luciano, C A; Dalakas, M; Gilliatt, R W; Bernardini, I; Ishak, K; Cwik, V A; Fraker, D; Brushart, T A; Gahl, W A

    1994-02-01

    Nephropathic cystinosis is a lysosomal storage disorder leading to renal failure by age 10 years. Prolonged patient survival following renal transplantation has allowed the development of previously unknown long-term complications. Muscle involvement has been reported in a single posttransplant cystinosis patient, but the range of clinical, electrophysiologic, and histologic features has not been fully described. Thirteen of 54 post-renal-transplant patients that we examined developed weakness and wasting in the small hand muscles, with or without facial weakness and dysphagia. Tendon reflexes were preserved and sensory examinations were normal. Electrophysiologic studies in 11 affected patients showed normal nerve conduction velocities and preserved sensory action potentials. The voluntary motor units in the affected distal muscles had reduced amplitude and brief duration, confirmed with quantitative electromyography in 4 patients. Biopsy of the severely affected abductor digiti minimi or extensor carpi radialis brevis muscles in 2 patients revealed marked fiber size variability, prominent acid phosphatase-positive vacuoles, and absence of fiber type grouping or inflammatory cells. Crystals of cystine were detected in perimysial cells but not within the muscle cell vacuoles. The muscle cystine content of clinically affected muscles was markedly elevated. We conclude that a distal vacuolar myopathy is a common late complication of untreated nephropathic cystinosis. Although the cause is unclear, the general lysosomal defect in this disease may also affect the lysosomes within muscle fibers.

  2. Evidence for a large radius of the 11Be projectile

    NASA Astrophysics Data System (ADS)

    So, W. Y.; Choi, K. S.; Cheoun, Myung-Ki; Kim, K. S.

    2016-05-01

    We investigate ratios of the elastic scattering cross section to Rutherford cross section, PE, and angular distributions of breakup cross section by using an optical model which exploits various long-range dynamic polarization potentials as well as short-range nuclear bare potentials for the 11Be projectile. From these simultaneous analyses, we extract a large radius of a halo projectile from the experimental data for PE and the angular distribution of the breakup cross section of the 11Be + 64Zn and 11 + 120Sn systems. It results from the fact that a large radius for the long-range nuclear potential is more reasonable for properly explaining these data simultaneously. The extracted reduced interaction radius turns out to be r0=3.18 ˜3.61 fm for 11Be nucleus, which is larger than the conventional value of r0=1.1 ˜1.5 fm used in the standard radius form R =r0A1 /3 . Furthermore, the larger radius as well as the normalization constant N is shown to be important for understanding Coulomb dipole strength distribution.

  3. The Mass - Radius Relation of Giant Gas Planets

    NASA Astrophysics Data System (ADS)

    Çelik Orhan, Zeynep; Kayhan, Cenk; Yildiz, Mutlu

    2016-07-01

    Thanks to CoRoT and Kepler space telescope, the thousand of exoplanets have been discovered. The only observational construct on planetary interior is planetary radius. Mass-radius relation is widely studied in the literature. Many mechanisms have been suggested in the literature to explain the inflated radii of these planets. In this study, our aim is to consider planet and host star interaction and assess the basic mechanisms responsible for excess in radius of transiting giant gas planets. We show that there is much more definite relation between radius and energy per gram per second (log (l- )). There is a good linear relation between planetary radius and log (l- ) for log (l- /l0 ) < 3.75. The relation changes if log (l- /l0 ) > 3.5. There is a relatively clump for the range log (l- /l0 ) > 3.75. The reason for the change in the relation may be related with the structure of the heated part of the planets. We focus on these inflated planet.

  4. Optimal network modification for spectral radius dependent phase transitions

    NASA Astrophysics Data System (ADS)

    Rosen, Yonatan; Kirsch, Lior; Louzoun, Yoram

    2016-09-01

    The dynamics of contact processes on networks is often determined by the spectral radius of the networks adjacency matrices. A decrease of the spectral radius can prevent the outbreak of an epidemic, or impact the synchronization among systems of coupled oscillators. The spectral radius is thus tightly linked to network dynamics and function. As such, finding the minimal change in network structure necessary to reach the intended spectral radius is important theoretically and practically. Given contemporary big data resources such as large scale communication or social networks, this problem should be solved with a low runtime complexity. We introduce a novel method for the minimal decrease in weights of edges required to reach a given spectral radius. The problem is formulated as a convex optimization problem, where a global optimum is guaranteed. The method can be easily adjusted to an efficient discrete removal of edges. We introduce a variant of the method which finds optimal decrease with a focus on weights of vertices. The proposed algorithm is exceptionally scalable, solving the problem for real networks of tens of millions of edges in a short time.

  5. The radius distribution of planets around cool stars

    SciTech Connect

    Morton, Timothy D.; Swift, Jonathan

    2014-08-10

    We calculate an empirical, non-parametric estimate of the shape of the period-marginalized radius distribution of planets with periods less than 150 days using the small yet well-characterized sample of cool (T{sub eff} < 4000 K) dwarf stars in the Kepler catalog. In particular, we present and validate a new procedure, based on weighted kernel density estimation, to reconstruct the shape of the planet radius function down to radii smaller than the completeness limit of the survey at the longest periods. Under the assumption that the period distribution of planets does not change dramatically with planet radius, we show that the occurrence of planets around these stars continues to increase to below 1 R{sub ⊕}, and that there is no strong evidence for a turnover in the planet radius function. In fact, we demonstrate using many iterations of simulated data that a spurious turnover may be inferred from data even when the true distribution continues to rise toward smaller radii. Finally, the sharp rise in the radius distribution below ∼3 R{sub ⊕} implies that a large number of planets await discovery around cool dwarfs as the sensitivities of ground-based transit surveys increase.

  6. Distal Communication by Chimpanzees (Pan troglodytes): Evidence for Common Ground?

    PubMed

    Leavens, David A; Reamer, Lisa A; Mareno, Mary Catherine; Russell, Jamie L; Wilson, Daniel; Schapiro, Steven J; Hopkins, William D

    2015-01-01

    van der Goot et al. (2014) proposed that distal, deictic communication indexed the appreciation of the psychological state of a common ground between a signaler and a receiver. In their study, great apes did not signal distally, which they construed as evidence for the human uniqueness of a sense of common ground. This study exposed 166 chimpanzees to food and an experimenter, at an angular displacement, to ask, "Do chimpanzees display distal communication?" Apes were categorized as (a) proximal or (b) distal signalers on each of four trials. The number of chimpanzees who communicated proximally did not statistically differ from the number who signaled distally. Therefore, contrary to the claim by van der Goot et al., apes do communicate distally.

  7. PHILOS humerus plate for a distal tibial fracture.

    PubMed

    Twaij, Haider; Damany, Dev

    2013-01-04

    This report discusses the use of an alternative implant in the emergency fixation of a distal tibial fracture. We planned to fix the shear-type medial malleolar fracture in a closed, tri-malleolar fracture with a locking distal tibial plate. Intra-operatively, it was noted that the required plate was unavailable. A PHILOS humeral plate seemed to fit the contours of the distal tibia. The broad end of the PHILOS, when placed distally, gave options to place locking screws in the medial malleolar fragment. The fracture was stable after fixation. The patient made a full post-operative recovery and follow-up at 4 months was satisfactory. Despite adequate planning, there will be instances where one has to improvise. An understanding of the principles of fracture management can aid in finding solutions. PHILOS humeral plate may be used to stabilize a distal tibial fracture if an appropriate distal tibial locking plate is not available.

  8. Distal Xq duplication and functional Xq disomy

    PubMed Central

    Sanlaville, Damien; Schluth-Bolard, Caroline; Turleau, Catherine

    2009-01-01

    Distal Xq duplications refer to chromosomal disorders resulting from involvement of the long arm of the X chromosome (Xq). Clinical manifestations widely vary depending on the gender of the patient and on the gene content of the duplicated segment. Prevalence of Xq duplications remains unknown. About 40 cases of Xq28 functional disomy due to cytogenetically visible rearrangements, and about 50 cases of cryptic duplications encompassing the MECP2 gene have been reported. The most frequently reported distal duplications involve the Xq28 segment and yield a recognisable phenotype including distinctive facial features (premature closure of the fontanels or ridged metopic suture, broad face with full cheeks, epicanthal folds, large ears, small and open mouth, ear anomalies, pointed nose, abnormal palate and facial hypotonia), major axial hypotonia, severe developmental delay, severe feeding difficulties, abnormal genitalia and proneness to infections. Xq duplications may be caused either by an intrachromosomal duplication or an unbalanced X/Y or X/autosome translocation. In XY males, structural X disomy always results in functional disomy. In females, failure of X chromosome dosage compensation could result from a variety of mechanisms, including an unfavourable pattern of inactivation, a breakpoint separating an X segment from the X-inactivation centre in cis, or a small ring chromosome. The MECP2 gene in Xq28 is the most important dosage-sensitive gene responsible for the abnormal phenotype in duplications of distal Xq. Diagnosis is based on clinical features and is confirmed by CGH array techniques. Differential diagnoses include Prader-Willi syndrome and Alpha thalassaemia-mental retardation, X linked (ATR-X). The recurrence risk is significant if a structural rearrangement is present in one of the parent, the most frequent situation being that of an intrachromosomal duplication inherited from the mother. Prenatal diagnosis is performed by cytogenetic testing

  9. Attractor radius, a new determination criterion of predictability limit

    NASA Astrophysics Data System (ADS)

    Liu, Deqiang; Ding, Ruiqiang; Li, Jianping; Feng, Jie

    2014-05-01

    Firstly, the definition of the attractor radius was given and then the property of that the attractor radius (AR) in a given n-dimensional attractor A is a constant was proved in theory. Secondly, the SV of the square of the RMS difference was separated into two components - the systematic error and the attractor radius, and it was proved that the observed global climatological RMS (OCR) difference is not equal to 71% of the SV of the RMS difference when the systematic error is existed, however, it is always equal to 71% of the AR. Then the physical understanding of the AR and also the predictability limit determinated by it were discussed. Finally, the spatial distributions of the predictability limit calculated from CFSv2 data by different criterions were compared.

  10. Improved radiographic visualization of calculus in distal ureter.

    PubMed

    Amar, A D

    1979-10-01

    Roentgenographic visualization of a calculus in the distal ureter is often made difficult by gas or bowel contents in the region of the pelvis. Filling the bladder with sterile water raises the bladder dome and displaces the bowel upward. Any calculus in the lower 4 to 5 cm. of the distal ureter is then clearly demonstrated on roentgenograms taken against the water-filled bladder instead of against the bowel filled with gas and feces. This maneuver also aids in differentiation of a calculus in the distal ureter from a phlebolith in the bladder wall, and has improved visualization of distal ureteral calculus in 50 patients during the last six years. PMID:494477

  11. Distal myopathy with rimmed vacuoles and cerebellar atrophy.

    PubMed

    Merkli, Hajnalka; Pál, Endre; Gáti, István; Czopf, József

    2006-01-01

    Distal myopathies constitute a clinically and pathologically heterogeneous group of genetically determined neuromuscular disorders, where the distal muscles of the upper or lower limbs are affected. The disease of a 41-year-old male patient started with gait disturbances, when he was 25. The progression was slow, but after 16 years he became seriously disabled. Neurological examination showed moderate to severe weakness in distal muscles of all extremities, marked cerebellar sign and steppage gait. Muscle biopsy resulted in myopathic changes with rimmed vacuoles. Brain MRI scan showed cerebellar atrophy. This case demonstrates a rare association of distal myopathy and cerebellar atrophy.

  12. Stability of a Wheel with Various Radius Rim

    NASA Astrophysics Data System (ADS)

    Kinugasa, Tetsuya; Yoshida, Koji

    This paper describes the dynamics and impact model of a wheel with various radius rim. The dynamics is expressed by a rst order linear ordinary dierential equation with respect to the absolute orientation of the wheel, and an analytic solution is derived. Poincaré map is also derived analytically. Stability and basin of attraction (BoA) of the Poincaré map are discussed. Finally, the analysis is validated through some numerical simulations. As a result, the rim radius aects the stability and broadens its BoA. The analysis helps understanding of not only a geometric tracking control but also many underactuated control methods for bipeds.

  13. Proton Charge Radius (PRad) Experiment at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Peng, C.; Gao, H.

    2016-03-01

    The puzzle of proton charge radius was recently raised by the measurement of muonic hydrogen Lamb shift at Paul Scherrer Institute (PSI), whose results were seven standard deviations smaller than the CODATA recommended value. To investigate this discrepancy, the PRad experiment was proposed and approved at Thomas Jefferson National Accelerator Facility (JLab). The experiment will extract the proton charge radius with a sub-percent accuracy by measuring the cross-sections of unpolarized electronproton elastic scattering in an unprecedented low Q2 region (2×10-4 GeV2/c2).

  14. The PRad experiment and the proton radius puzzle

    SciTech Connect

    Gasparian, Ashot H.

    2014-06-01

    New results from the recent muonic hydrogen experiments seriously questioned our knowledge of the proton charge radius, r_p. The new value, with its unprecedented less than sub-percent precision, is currently up to eight standard deviation smaller than the average value from all previous experiments, triggering the well-known "proton charge radius puzzle" in nuclear and atomic physics. The PRad collaboration is currently preparing a novel, magnetic-spectrometer-free ep scattering experiment in Hall B at JLab for a new independent r_p measurement to address this growing "puzzle" in physics.

  15. About the horizontal variability of effective radius in stratocumulus clouds

    NASA Astrophysics Data System (ADS)

    Magaritz-Ronen, L.; Khain, A.; Pinsky, M.

    2016-08-01

    The role of turbulent mixing in formation of low horizontal variability of effective radius near the top of nondrizzling stratocumulus clouds is investigated in simulations of clouds observed during the Second Dynamics and Chemistry of Marine Stratocumulus field experiment. The clouds are simulated using a spectral bin microphysics Lagrangian-Eulerian model consisting of ~2000 adjacent parcels moving in a turbulence-like field with observed correlation properties. The parcels interact through drop sedimentation and turbulent mixing. It was found that the effective radius variability in the horizontal direction near cloud top does not exceed ~10% of the averaged value. Three different types of cloud parcels are revealed to be differently influenced by mixing: ascending slightly diluted parcels, cloudy parcels experiencing intense mixing with parcels from inversion, and initially dry parcels. The evolution of droplet size distributions in parcels belonging to these types is investigated. It is shown that in parcels of the first two types the values of effective radii do not change or change only slightly remaining close to the adiabatic value. In initially droplet-free parcels effective radius rapidly reaches a value close to the adiabatic value, while liquid water content remains low. Therefore, turbulent mixing leads to establishing vertical profiles of effective radius, which are close to the adiabatic profile.

  16. Nonlinear buckling analyses of a small-radius carbon nanotube

    NASA Astrophysics Data System (ADS)

    Liu, Ning; Wang, Yong-Gang; Li, Min; Jia, Jiao

    2014-04-01

    Carbon nanotube (CNT) was first discovered by Sumio Iijima. It has aroused extensive attentions of scholars from all over the world. Over the past two decades, we have acquired a lot of methods to synthesize carbon nanotubes and learn their many incredible mechanical properties such as experimental methods, theoretical analyses, and computer simulations. However, the studies of experiments need lots of financial, material, and labor resources. The calculations will become difficult and time-consuming, and the calculations may be even beyond the realm of possibility when the scale of simulations is large, as for computer simulations. Therefore, it is necessary for us to explore a reasonable continuum model, which can be applied into nano-scale. This paper attempts to develop a mathematical model of a small-radius carbon nanotube based on continuum theory. An Isotropic circular cross-section, Timoshenko beam model is used as a simplified mechanical model for the small-radius carbon nanotube. Theoretical part is mainly based on modified couple stress theory to obtain the numerical solutions of buckling deformation. Meanwhile, the buckling behavior of the small radius carbon nanotube is simulated by Molecular Dynamics method. By comparing with the numerical results based on modified couple stress theory, the dependence of the small-radius carbon nanotube mechanical behaviors on its elasticity constants, small-size effect, geometric nonlinearity, and shear effect is further studied, and an estimation of the small-scale parameter of a CNT (5, 5) is obtained.

  17. Focus retrocollimated interferometry for long-radius-of-curvature measurement

    NASA Astrophysics Data System (ADS)

    Xiang, Yang

    2001-12-01

    Focus retrocollimated interferometry is described for measuring long radius of curvature (>1 m), and achievable accuracy is discussed. It is shown that this method can be applied to both concave and convex spherical surfaces and can provide measurement to accuracy of 0.01-0.1%.

  18. Finite Larmor radius flute mode theory with end loss

    SciTech Connect

    Kotelnikov, I.A.; Berk, H.L.

    1993-08-01

    The theory of flute mode stability is developed for a two-energy- component plasma partially terminated by a conducting limiter. The formalism is developed as a preliminary study of the effect of end-loss in open-ended mirror machines where large Larmor radius effects are important.

  19. Nonlinear buckling analyses of a small-radius carbon nanotube

    SciTech Connect

    Liu, Ning Li, Min; Jia, Jiao; Wang, Yong-Gang

    2014-04-21

    Carbon nanotube (CNT) was first discovered by Sumio Iijima. It has aroused extensive attentions of scholars from all over the world. Over the past two decades, we have acquired a lot of methods to synthesize carbon nanotubes and learn their many incredible mechanical properties such as experimental methods, theoretical analyses, and computer simulations. However, the studies of experiments need lots of financial, material, and labor resources. The calculations will become difficult and time-consuming, and the calculations may be even beyond the realm of possibility when the scale of simulations is large, as for computer simulations. Therefore, it is necessary for us to explore a reasonable continuum model, which can be applied into nano-scale. This paper attempts to develop a mathematical model of a small-radius carbon nanotube based on continuum theory. An Isotropic circular cross-section, Timoshenko beam model is used as a simplified mechanical model for the small-radius carbon nanotube. Theoretical part is mainly based on modified couple stress theory to obtain the numerical solutions of buckling deformation. Meanwhile, the buckling behavior of the small radius carbon nanotube is simulated by Molecular Dynamics method. By comparing with the numerical results based on modified couple stress theory, the dependence of the small-radius carbon nanotube mechanical behaviors on its elasticity constants, small-size effect, geometric nonlinearity, and shear effect is further studied, and an estimation of the small-scale parameter of a CNT (5, 5) is obtained.

  20. Optimal Taylor-Couette flow: radius ratio dependence

    NASA Astrophysics Data System (ADS)

    Ostilla-Mónico, Rodolfo; Huisman, Sander G.; Jannink, Tim J. G.; Van Gils, Dennis P. M.; Verzicco, Roberto; Grossmann, Siegfried; Sun, Chao; Lohse, Detlef

    2014-05-01

    Taylor-Couette flow with independently rotating inner (i) and outer (o) cylinders is explored numerically and experimentally to determine the effects of the radius ratio {\\eta} on the system response. Numerical simulations reach Reynolds numbers of up to Re_i=9.5 x 10^3 and Re_o=5x10^3, corresponding to Taylor numbers of up to Ta=10^8 for four different radius ratios {\\eta}=r_i/r_o between 0.5 and 0.909. The experiments, performed in the Twente Turbulent Taylor-Couette (T^3C) setup, reach Reynolds numbers of up to Re_i=2x10^6$ and Re_o=1.5x10^6, corresponding to Ta=5x10^{12} for {\\eta}=0.714-0.909. Effective scaling laws for the torque J^{\\omega}(Ta) are found, which for sufficiently large driving Ta are independent of the radius ratio {\\eta}. As previously reported for {\\eta}=0.714, optimum transport at a non-zero Rossby number Ro=r_i|{\\omega}_i-{\\omega}_o|/[2(r_o-r_i){\\omega}_o] is found in both experiments and numerics. Ro_opt is found to depend on the radius ratio and the driving of the system. At a driving in the range between {Ta\\sim3\\cdot10^8} and {Ta\\sim10^{10}}, Ro_opt saturates to an asymptotic {\\eta}-dependent value. Theoretical predictions for the asymptotic value of Ro_{opt} are compared to the experimental results, and found to differ notably. Furthermore, the local angular velocity profiles from experiments and numerics are compared, and a link between a flat bulk profile and optimum transport for all radius ratios is reported.

  1. OBSERVATIONAL CONSTRAINTS ON THE DEGENERATE MASS-RADIUS RELATION

    SciTech Connect

    Holberg, J. B.; Oswalt, T. D.; Barstow, M. A. E-mail: toswalt@fit.edu

    2012-03-15

    The white dwarf mass-radius relationship is fundamental to modern astrophysics. It is central to routine estimation of DA white dwarf masses derived from spectroscopic temperatures and gravities. It is also the basis for observational determinations of the white dwarf initial-final-mass relation. Nevertheless, definitive and detailed observational confirmations of the mass-radius relation (MRR) remain elusive owing to a lack of sufficiently accurate white dwarf masses and radii. Current best estimates of masses and radii allow only broad conclusions about the expected inverse relation between masses and radii in degenerate stars. In this paper, we examine a restricted set of 12 DA white dwarf binary systems for which accurate (1) trigonometric parallaxes, (2) spectroscopic effective temperatures and gravities, and (3) gravitational redshifts are available. We consider these three independent constraints on mass and radius in comparison with an appropriate evolved MRR for each star. For the best-determined systems it is found that the DA white dwarfs conform to evolve theoretical MRRs at the 1{sigma} to 2{sigma} level. For the white dwarf 40 Eri B (WD 0413-077) we find strong evidence for the existence of a 'thin' hydrogen envelope. For other stars improved parallaxes will be necessary before meaningful comparisons are possible. For several systems current parallaxes approach the precision required for the state-of-the-art mass and radius determinations that will be obtained routinely from the Gaia mission. It is demonstrated here how these anticipated results can be used to firmly constrain details of theoretical mass-radius determinations.

  2. Young Children's Sibling Relationship Quality: Distal and Proximal Correlates

    ERIC Educational Resources Information Center

    Kretschmer, Tina; Pike, Alison

    2009-01-01

    Background: Relationships within families are interdependent and related to distal environmental factors. Low socioeconomic status (SES) and high household chaos (distal factors) have been linked to less positive marital and parent-child relationships, but have not yet been examined with regard to young children's sibling relationships. The…

  3. Giant serpentine aneurysm of the distal anterior cerebral artery.

    PubMed

    Senbokuya, Nobuo; Kanemaru, Kazuya; Kinouchi, Hiroyuki; Horikoshi, Toru

    2012-11-01

    We report a case of a 38-year-old man with a giant serpentine aneurysm arising from the distal anterior cerebral artery. This aneurysm grew from a fusiform aneurysm to a huge aneurysm within 5 months before manifesting as a mass lesion. The aneurysm was largely filled with thrombus, and 4 distal branches arose from the aneurysm dome. Selective balloon test occlusion of the distal anterior cerebral artery using an intravascular technique was performed to confirm the tolerance of the brain tissue. The balloon test occlusion elicited adequate leptomeningeal collateral circulation and no neurologic symptoms; thus, the aneurysm was treated with trapping and resection. The patient had no ischemic complications after the surgery and returned to his job 1 month later. No ischemia developed in the 2 years after surgery. Selective balloon test occlusion of the distal cerebral artery using an intravascular technique can be a very useful tool in planning the therapeutic strategy for a complicated distal cerebral aneurysm.

  4. Variable radius cartography - History and perspectives of a new discipline

    NASA Astrophysics Data System (ADS)

    Scalera, Giancarlo

    2014-05-01

    The map that Toscanelli sent to Columbus was an unconscious application of cartography at a smaller radius than the real. The first really conscious attempts to represent the geography of Earth on globes of radius less than the current one occurred after the formulation of the concept of expanding Earth through geological time. The American chemist and geologist Richard Owen (1810-1890) in his book Key to the geology of the globe (1857) described the principles of what he himself called Anatomical Geology, with the Earth growing as a biological organism. The book contained a global paleogeographic map of the Earth that would have had a radius of about 4000 kilometers. In 1928 J.A.H. Kerkhoff (under the pseudonym Aero-dilettant) published a series of paleogeographic globes on which the modern oceans disappeared. With the same artisan methods of transfer continental outlines from a sphere to a smaller one, in 1933 O.C. Hilgenberg represented three different geological epochs, and, later, for the first time mapped paleopoles with their site-pole segments of meridian. Even today the traditional method of Hilgenberg is followed by senior researchers (Klaus Vogel, 2003) and younger geologists (James Maxlow). In England Hugh Owen applied the methods of traditional cartography to the variable radius one. His Atlas of Continental Displacement was in the 70s and 80s, for this discipline, a real milestone. While in the field of constant radius paleogeography the adherents to plate tectonics created many computer codes of automatic mapping (Bullard et al., 1965; Smith & Hallam, 1970; Scotese et al., 1979; and many others), in the variable radius field few tried to reach the same task. In 1972 in United States a first very simple attempt (but was not further developed) came from a private, R.B. Perry, followed by the still not-computerized Atlas of Owen, and both them constituted inspiration for the construction of a FORTRAN variable radius mapping code at INGV, with which it

  5. A 3-Dimensional Anatomic Study of the Distal Biceps Tendon

    PubMed Central

    Walton, Christine; Li, Zhi; Pennings, Amanda; Agur, Anne; Elmaraghy, Amr

    2015-01-01

    Background Complete rupture of the distal biceps tendon from its osseous attachment is most often treated with operative intervention. Knowledge of the overall tendon morphology as well as the orientation of the collagenous fibers throughout the musculotendinous junction are key to intraoperative decision making and surgical technique in both the acute and chronic setting. Unfortunately, there is little information available in the literature. Purpose To comprehensively describe the morphology of the distal biceps tendon. Study Design Descriptive laboratory study. Methods The distal biceps terminal musculature, musculotendinous junction, and tendon were digitized in 10 cadaveric specimens and data reconstructed using 3-dimensional modeling. Results The average length, width, and thickness of the external distal biceps tendon were found to be 63.0, 6.0, and 3.0 mm, respectively. A unique expansion of the tendon fibers within the distal muscle was characterized, creating a thick collagenous network along the central component between the long and short heads. Conclusion This study documents the morphologic parameters of the native distal biceps tendon. Reconstruction may be necessary, especially in chronic distal biceps tendon ruptures, if the remaining tendon morphology is significantly compromised compared with the native distal biceps tendon. Knowledge of normal anatomical distal biceps tendon parameters may also guide the selection of a substitute graft with similar morphological characteristics. Clinical Relevance A thorough description of distal biceps tendon morphology is important to guide intraoperative decision making between primary repair and reconstruction and to better select the most appropriate graft. The detailed description of the tendinous expansion into the muscle may provide insight into better graft-weaving and suture-grasping techniques to maximize proximal graft incorporation. PMID:26665092

  6. Motion Perception During Variable-Radius Swing Motion in Darkness

    PubMed Central

    Rader, A. A.; Oman, C. M.; Merfeld, D. M.

    2009-01-01

    Using a variable-radius roll swing motion paradigm, we examined the influence of interaural (y-axis) and dorsoventral (z-axis) force modulation on perceived tilt and translation by measuring perception of horizontal translation, roll tilt, and distance from center of rotation (radius) at 0.45 and 0.8 Hz using standard magnitude estimation techniques (primarily verbal reports) in darkness. Results show that motion perception was significantly influenced by both y- and z-axis forces. During constant radius trials, subjects' perceptions of tilt and translation were generally almost veridical. By selectively pairing radius (1.22 and 0.38 m) and frequency (0.45 and 0.8 Hz, respectively), the y-axis acceleration could be tailored in opposition to gravity so that the combined y-axis gravitoinertial force (GIF) variation at the subject's ears was reduced to ∼0.035 m/s2 – in effect, the y-axis GIF was “nulled” below putative perceptual threshold levels. With y-axis force nulling, subjects overestimated their tilt angle and underestimated their horizontal translation and radius. For some y-axis nulling trials, a radial linear acceleration at twice the tilt frequency (0.25 m/s2 at 0.9 Hz, 0.13 m/s2 at 1.6 Hz) was simultaneously applied to reduce the z-axis force variations caused by centripetal acceleration and by changes in the z-axis component of gravity during tilt. For other trials, the phase of this radial linear acceleration was altered to double the magnitude of the z-axis force variations. z-axis force nulling further increased the perceived tilt angle and further decreased perceived horizontal translation and radius relative to the y-axis nulling trials, while z-axis force doubling had the opposite effect. Subject reports were remarkably geometrically consistent; an observer model-based analysis suggests that perception was influenced by knowledge of swing geometry. PMID:19625542

  7. Motion perception during variable-radius swing motion in darkness.

    PubMed

    Rader, A A; Oman, C M; Merfeld, D M

    2009-10-01

    Using a variable-radius roll swing motion paradigm, we examined the influence of interaural (y-axis) and dorsoventral (z-axis) force modulation on perceived tilt and translation by measuring perception of horizontal translation, roll tilt, and distance from center of rotation (radius) at 0.45 and 0.8 Hz using standard magnitude estimation techniques (primarily verbal reports) in darkness. Results show that motion perception was significantly influenced by both y- and z-axis forces. During constant radius trials, subjects' perceptions of tilt and translation were generally almost veridical. By selectively pairing radius (1.22 and 0.38 m) and frequency (0.45 and 0.8 Hz, respectively), the y-axis acceleration could be tailored in opposition to gravity so that the combined y-axis gravitoinertial force (GIF) variation at the subject's ears was reduced to approximately 0.035 m/s(2) - in effect, the y-axis GIF was "nulled" below putative perceptual threshold levels. With y-axis force nulling, subjects overestimated their tilt angle and underestimated their horizontal translation and radius. For some y-axis nulling trials, a radial linear acceleration at twice the tilt frequency (0.25 m/s(2) at 0.9 Hz, 0.13 m/s(2) at 1.6 Hz) was simultaneously applied to reduce the z-axis force variations caused by centripetal acceleration and by changes in the z-axis component of gravity during tilt. For other trials, the phase of this radial linear acceleration was altered to double the magnitude of the z-axis force variations. z-axis force nulling further increased the perceived tilt angle and further decreased perceived horizontal translation and radius relative to the y-axis nulling trials, while z-axis force doubling had the opposite effect. Subject reports were remarkably geometrically consistent; an observer model-based analysis suggests that perception was influenced by knowledge of swing geometry. PMID:19625542

  8. Effect of coffee on distal colon function.

    PubMed Central

    Brown, S R; Cann, P A; Read, N W

    1990-01-01

    Ninety nine healthy young volunteers (58 men, 34 women, aged 17-27 years) answered a questionnaire concerning their bowel habit with particular reference to the effects of beverages. Twenty nine per cent (63% women) claimed that coffee induced a desire to defecate. The rectosigmoid motor responses to black, unsweetened coffee were then investigated by multiport manometry in 14 healthy-subjects (12 men, two women, eight of whom claimed coffee caused a desire to defecate (responders). Results revealed an increase in motility index within four minutes after ingestion of both regular and decaffeinated coffee (p less than 0.05) in the eight responders, but not in the six non-responders. The increase in rectosigmoid motility induced by coffee lasted at least 30 minutes. There was no increase in the motility index in any subject after a drink of hot water. These results suggest that drinking coffee can stimulate a motor response of the distal colon in some normal people. PMID:2338272

  9. Distal Stressors and Depression among Homeless Men.

    PubMed

    Coohey, Carol; Easton, Scott D

    2016-05-01

    Depression is a common problem among homeless men that may interfere with functional tasks, such as securing stable housing, obtaining employment, and accessing health services. Previous research on depression among homeless men has largely focused on current psychosocial resources, substance abuse, and past victimization. Guided by Ensel and Lin's life course stress process model, the authors examined whether distal stressors, including victimization and exposure to parent problems in childhood, contributed to men's depression above and beyond current (or proximal) stressors, such as substance abuse and health problems, and social resources. The sample consisted of 309 homeless men who had entered a federally funded emergency shelter. Using the Burns Depression Checklist, the authors found that one out of three men met the threshold for moderate to severe depression during the past week. The logistic regression showed that past exposure to parent problems was related to depression after accounting for current stressors and social resources (number of close adult relationships and whether their emotional support needs were met). Past victimization was not related to depression. To address men's depression, workers should concurrently provide services that meet men's basic needs (for example, housing) and address their relationship needs, including their need for emotional support. PMID:27263201

  10. Measurements of small radius ratio turbulent Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    van der Veen, Roeland; Huisman, Sander; Merbold, Sebastian; Sun, Chao; Harlander, Uwe; Egbers, Christoph; Lohse, Detlef

    2014-11-01

    In Taylor-Couette flows, the radius ratio (η =ri /ro) is one of the key parameters of the system. For small η, the asymmetry of the inner and outer boundary layer becomes more important, affecting the general flow structure and boundary layer characteristics. Using high-resolution particle image velocimetry we measure flow profiles, local transport, and statistical properties of the flow for a radius ratio of 0.5 and a Reynolds number of up to 4 .104 . By measuring flow profiles at varying heights, roll structures are characterized for two different rotation ratios of the inner and outer cylinder. In addition, we systematically vary the rotation ratio and the Reynolds number. These results exemplify how curvature affects flow in strongly turbulent Taylor-Couette Flow.

  11. Artificial gravity: head movements during short-radius centrifugation

    NASA Astrophysics Data System (ADS)

    Young, Laurence R.; Hecht, Heiko; Lyne, Lisette E.; Sienko, Kathleen H.; Cheung, Carol C.; Kavelaars, Jessica

    2001-08-01

    Short-radius centrifugation is a potential countermeasure to long-term weightlessness. Unfortunately, head movements in a rotating environment induce serious discomfort, non-compensatory vestibulo-ocular reflexes, and subjective illusions of body tilt. In two experiments we investigated the effects of pitch and yaw head movements in participants placed supine on a rotating bed with their head at the center of rotation, feel at the rim. The vast majority of participants experienced motion sickness, inappropriate vertical nystagmus and illusory tilt and roll as predicted by a semicircular canal model. However, a small but significant number of the 28 participants experienced tilt in the predicted plane but in the opposite direction. Heart rate was elevated following one-second duration head turns. Significant adaptation occurred following a series of head turns in the light. Vertical nystagmus, motion sickness and illusory tilt all decreased with adaptation. Consequences for artificial gravity produced by short-radius centrifuges as a countermeasure are discussed.

  12. Flute waves at the ion Larmor radius scales

    SciTech Connect

    Onishchenko, O. G.

    2010-12-14

    The theory of the magnetic Rayleigh-Taylor instability (RTI) is discussed. Modified linear kinetic theory allows us to investigate RTI and flute waves with arbitrary perpendicular spatial scales compared to the ion Larmor radius. It is shown that in the linear limit a Fourier transform of these equations yields the dispersion relation which in the so-called Pade approximation corresponds to results of the kinetic theory. This analysis represents an extension of the previous study of the magnetic RTI obtained in the large wave scale approximation. It is shown that incorporation of the effects associated with wave scales of the order of the ion Larmor radius leads to a broader wave number range of the magnetic RTI.

  13. Maximal radius of the aftershock zone in earthquake networks

    NASA Astrophysics Data System (ADS)

    Mezentsev, A. Yu.; Hayakawa, M.

    2009-09-01

    In this paper, several seismoactive regions were investigated (Japan, Southern California and two tectonically distinct Japanese subregions) and structural seismic constants were estimated for each region. Using the method for seismic clustering detection proposed by Baiesi and Paczuski [M. Baiesi, M. Paczuski, Phys. Rev. E 69 (2004) 066106; M. Baiesi, M. Paczuski, Nonlin. Proc. Geophys. (2005) 1607-7946], we obtained the equation of the aftershock zone (AZ). It was shown that the consideration of a finite velocity of seismic signal leads to the natural appearance of maximal possible radius of the AZ. We obtained the equation of maximal radius of the AZ as a function of the magnitude of the main event and estimated its values for each region.

  14. Core Deuterium Fusion and Radius Inflation in Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Jaikumar, Prashanth; Rachid Ouyed

    2016-06-01

    Several laboratory-based studies have shown that the Deuterium fusion cross-section is enhanced in a solid deuterated target as compared to a gas target, attributable to enhanced mobility of deuterons in a metal lattice. As an application, we propose that, for core temperatures and compositions characterizing hot Jupiters, screened Deuterium fusion can occur deep in the interior, and show that the amount of radius inflation from this effect can be important if there is sufficient rock-ice in the core. The mechanism of screened Deuterium fusion, operating in the above temperature range, is generally consistent with the trend in radius anomaly with planetary equilibrium temperature. We also explore the trend with planetary mass using a simple analytic model.

  15. Predicting jet radius in electrospinning by superpositioning exponential functions

    NASA Astrophysics Data System (ADS)

    Widartiningsih, P. M.; Iskandar, F.; Munir, M. M.; Viridi, S.

    2016-08-01

    This paper presents an analytical study of the correlation between viscosity and fiber diameter in electrospinning. Control over fiber diameter in electrospinning process was important since it will determine the performance of resulting nanofiber. Theoretically, fiber diameter was determined by surface tension, solution concentration, flow rate, and electric current. But experimentally it had been proven that significantly viscosity had an influence to fiber diameter. Jet radius equation in electrospinning process was divided into three areas: near the nozzle, far from the nozzle, and at jet terminal. There was no correlation between these equations. Superposition of exponential series model provides the equations combined into one, thus the entire of working parameters on electrospinning take a contribution to fiber diameter. This method yields the value of solution viscosity has a linear relation to jet radius. However, this method works only for low viscosity.

  16. Increased risk of distal ventriculoperitoneal shunt obstruction associated with slit valves or distal slits in the peritoneal catheter.

    PubMed

    Cozzens, J W; Chandler, J P

    1997-11-01

    The authors describe a relationship between the presence of distal shunt catheter side-wall slits and distal catheter obstruction in a single-surgeon series of ventriculoperitoneal (VP) shunt revisions. Between 1985 and 1996, 168 operations for VP shunt revision were performed by the senior author (J.W.C.) in 71 patients. Indications for shunt revision included obstruction in 140 operations; overdrainage or underdrainage requiring a change of valve in 17 operations; inadequate length of distal shunt tubing resulting in the distal end no longer reaching the peritoneum in five operations; the ventricular catheter in the wrong ventricle or space, requiring repositioning in five operations; and a disconnected or broken shunt in one operation. Of the 140 instances of shunt obstruction, the blockage occurred at the ventricular end in 108 instances (77.1%), the peritoneal end in 17 (12.1%), the ventricular and the peritoneal end in 14 (10%), and in the valve mechanism (not including distal slit valves) in one (0.8%). Thus, the peritoneal end was obstructed in 31 (22.1%) of 140 cases of shunt malfunction. In every case in which the peritoneal end was obstructed, some form of distal slit was found: either a distal slit valve in an otherwise closed catheter or slits in the side of an open catheter. No instances were found of distal peritoneal catheter obstruction when the peritoneal catheter was a simple open-ended tube with no accompanying side slits (0 of 55). It is concluded that side slits in the distal peritoneal catheters of VP shunts are associated with a greater incidence of distal shunt obstruction.

  17. Treatment of the distal fracture in radioulna based on the volar wrist dual channel approach and postoperative X-ray diagnosis.

    PubMed

    Li, Zheng; Zhang, Zhenwei; Yu, Shaoxiao; Bai, Yinwei; Lin, Huixin; Zeng, Jinhao; Ye, Xuelang; Xu, Dachuan

    2015-12-01

    The fracture of the distal ulna and radius is a kind of fracture that results in high morbidity and occurrence rate and contributes to about one-sixth of the entire body's fracture. In this study, we implemented the improved palmar wrist surgery by a volar wrist dual channel approach. Between 2011 and 2014, we have treated 67 distal radius fracture patients. We divided them into two parts randomly, and treat them by the Carpometacarpal direct approach solution and dual wrist palmar surgical approach solution respectively. After the surgery, the differences in the incidence of median nerve irritation are significant (P < 0.01). With reference to the exposure time of fracture, the operation time and the pronator quadratus muscle repair rate, we find that the exposure time of fracture and the operation time in the dual wrist palmar surgical approach solution are much less than that as compared to the Carpometacarpal direct approach solution (P < 0.01). The improved dual wrist palmar surgical approach can lead to a successful treatment of the distal radius fractures volar distal radial ulnar by reducing the blind exposure problem. As such, the surgeon can complete treatment of fractures of the region under direct vision during operation. Furthermore, reducing the median nerve in the carpal tunnel and the structure of the stretch can decrease the incidence of postoperative complications. Postoperative X-ray diagnosis is then performed to examine the patients' recovery and assist in clinical follow-up. Our study proves that the volar wrist dual channel approach can be successfully achieved by a surface incision surgical implementation of the dual channel, and gives rise to a minimally invasive operation.

  18. Treatment of the distal fracture in radioulna based on the volar wrist dual channel approach and postoperative X-ray diagnosis.

    PubMed

    Li, Zheng; Zhang, Zhenwei; Yu, Shaoxiao; Bai, Yinwei; Lin, Huixin; Zeng, Jinhao; Ye, Xuelang; Xu, Dachuan

    2015-12-01

    The fracture of the distal ulna and radius is a kind of fracture that results in high morbidity and occurrence rate and contributes to about one-sixth of the entire body's fracture. In this study, we implemented the improved palmar wrist surgery by a volar wrist dual channel approach. Between 2011 and 2014, we have treated 67 distal radius fracture patients. We divided them into two parts randomly, and treat them by the Carpometacarpal direct approach solution and dual wrist palmar surgical approach solution respectively. After the surgery, the differences in the incidence of median nerve irritation are significant (P < 0.01). With reference to the exposure time of fracture, the operation time and the pronator quadratus muscle repair rate, we find that the exposure time of fracture and the operation time in the dual wrist palmar surgical approach solution are much less than that as compared to the Carpometacarpal direct approach solution (P < 0.01). The improved dual wrist palmar surgical approach can lead to a successful treatment of the distal radius fractures volar distal radial ulnar by reducing the blind exposure problem. As such, the surgeon can complete treatment of fractures of the region under direct vision during operation. Furthermore, reducing the median nerve in the carpal tunnel and the structure of the stretch can decrease the incidence of postoperative complications. Postoperative X-ray diagnosis is then performed to examine the patients' recovery and assist in clinical follow-up. Our study proves that the volar wrist dual channel approach can be successfully achieved by a surface incision surgical implementation of the dual channel, and gives rise to a minimally invasive operation. PMID:26206398

  19. Radius fracture from an electrical injury involving an electric guitar.

    PubMed

    Pappano, Dante

    2010-03-01

    Electrical injury ranges widely from simple shock and mild burns to more extensive superficial injury, internal injury, and mortality. Bony fracture from electrically-induced tetanic muscle contraction is a rare but recognized injury. We report the case of a 14-year-old boy who suffered a minor burn and radius fracture related to an electrical injury involving his electric guitar. An interesting pattern is emerging from available case reports of similar injuries.

  20. Métastase osseuse isolée du radius métachrone d’un cancer rectal

    PubMed Central

    Eddekkaoui, Houda; Chekrine, Tarik; Sahraoui, Souha; Marouane, Sofia; Alj, Amina; Zamiati, Soumaya; Nechad, Mohamed; Benider, Abdellatif

    2013-01-01

    Les métastases osseuses isolées des cancers colorectaux sont très rares. Le squelette axial est habituellement le plus atteint. La localisation au niveau du radius est exceptionnelle. Nous rapportons l'observation d'une femme âgée de 60 ans avec une métastase du radius distal isolée métachrone d'un cancer du haut rectum opéré un an auparavant. La métastase a été découverte sur les examens d'imagerie et confirmée par biopsie. Une amputation a été réalisée suite à une progression de la maladie après une radiothérapie palliative. L'évolution était marquée par l'apparition de métastases pulmonaires et le décès est survenu dans un tableau de défaillance respiratoire. PMID:23819003

  1. Effective Radius Retrieval Using Microwave and Near-Infrared Observations

    NASA Astrophysics Data System (ADS)

    Schofield, R.; Daniel, J. S.; Solomon, S.; Miller, H. L.; Portmann, R. W.; Turner, D. D.

    2005-12-01

    The role that aerosols play in changing the radiative properties of clouds is uncertain, with even the sign of the forcing undetermined. The need for remotely sensing clouds is becoming more apparent with the desire to achieve a global estimate of the radiative forcing due to changes in clouds. A new technique of combining microwave and near-infrared spectroscopic measurements of liquid water path (LWP) and path integrated liquid water path (PLWP) respectively, to obtain effective radius information is outlined. Microwave measurements of brightness temperature are made routinely as part of the Aerosol and Radiation Measurement (ARM) program. Near-infrared measurements are conducted using spectroscopic measurements made in the wavelength region between 900 and 1700 nm. The effective radius of clouds is retrieved using an optimal estimation retrieval scheme that takes into account the measurements, their uncertainties, prior knowledge of the effective radius and its uncertainty. The technique is applied to ground-based observations of clouds made during September at Barrow, Alaska, 2004.

  2. Explaining the proton radius puzzle with disformal scalars

    NASA Astrophysics Data System (ADS)

    Brax, Philippe; Burrage, Clare

    2015-02-01

    We analyze the consequences of a disformal interaction between a massless scalar and matter particles in the context of atomic physics. We focus on the displacement of the atomic energy levels that it induces, and in particular the change in the Lamb shift between the 2s and 2p states. We find that the correction to the Lamb shift depends on the mass of the fermion orbiting around the nucleus, implying a larger effect for muonic atoms. Taking the cutoff scale describing the effective scalar field theory close to the QCD scale, we find that the disformal interaction can account for the observed difference in the proton radius of muonic versus electronic hydrogen. Explaining the proton radius puzzle is only possible when the scalar field is embedded in nonlinear theories which alleviate constraints from collider and stellar physics. Short distance properties of the Galileon where nonperturbative effects in vacuum are present ensure that unitarity is preserved in high-energy particle collisions. In matter, the chameleon mechanism alleviates the constraints on disformal interactions coming from the burning rates for stellar objects. We show how to combine these two properties in a single model which renders the proposed explanation of the proton radius puzzle viable.

  3. Is the proton radius puzzle evidence of extra dimensions?

    NASA Astrophysics Data System (ADS)

    Dahia, F.; Lemos, A. S.

    2016-08-01

    The proton charge radius inferred from muonic hydrogen spectroscopy is not compatible with the previous value given by CODATA-2010, which, on its turn, essentially relies on measurements of the electron-proton interaction. The proton's new size was extracted from the 2S-2P Lamb shift in the muonic hydrogen, which showed an energy excess of 0.3 meV in comparison to the theoretical prediction, evaluated with the CODATA radius. Higher-dimensional gravity is a candidate to explain this discrepancy, since the muon-proton gravitational interaction is stronger than the electron-proton interaction and, in the context of braneworld models, the gravitational potential can be hugely amplified in short distances when compared to the Newtonian potential. Motivated by these ideas, we study a muonic hydrogen confined in a thick brane. We show that the muon-proton gravitational interaction modified by extra dimensions can provide the additional separation of 0.3 meV between the 2S and 2P states. In this scenario, the gravitational energy depends on the higher-dimensional Planck mass and indirectly on the brane thickness. Studying the behavior of the gravitational energy with respect to the brane thickness in a realistic range, we find constraints for the fundamental Planck mass that solve the proton radius puzzle and are consistent with previous experimental bounds.

  4. Experimental bound on the charge radius of the electron neutrino

    SciTech Connect

    Allen, R.C.; Chen, H.H.; Doe, P.J.; Hausamann, R.; Lee, W.P.; Lu, X.; Mahler, H.J.; Potter, M.E.; Wang, K.C. ); Bowles, T.J.; Burman, R.L.; Carlini, R.D.; Cochran, D.R.F.; Frank, J.S.; Piasetzky, E.; Sandberg, V.D. ); Krakauer, D.A.; Talaga, R.L. )

    1991-01-01

    A limit on the electron-neutrino charge radius {vert bar}{ital r}{vert bar} is derived from a measurement of the weak-neutral-current vector coupling constant {ital g}{sub {ital V}} obtained in electron-neutrino electron elastic scattering. The 90%-confidence interval for {ital g}{sub {ital V}} is {minus}0.177{lt}{ital g}{sub {ital V}}{lt}0.187, which for sin{sup 2}{theta}{sub {ital W}}=0.227 implies that the {nu}{sub {ital e}} mean-square charge radius is in the range {minus}2.74{times}10{sup {minus}32}{lt}{l angle}{ital r}{sup 2}{r angle}{lt}4.88{times}10{sup {minus}32} cm{sup 2}, or simply {vert bar}{ital r}{vert bar}{lt}2.2{times}10{sup {minus}16} cm. This is the first experimental bound on the {nu}{sub {ital e}} charge radius, and is the same order of magnitude as bounds for {nu}{sub {mu}} structure.

  5. Experimental investigation of streamer radius and length in SF6

    NASA Astrophysics Data System (ADS)

    Bujotzek, M.; Seeger, M.; Schmidt, F.; Koch, M.; Franck, C.

    2015-06-01

    SF6 has for decades been widely used in high voltage insulation and switching applications, e.g. in gas insulated switchgear. Despite its widespread use some important parameters, like the properties of streamers, are still not sufficiently understood. Since breakdown in SF6 always occurs via the streamer-leader transition the streamer properties are decisive for leader inception and, therefore, breakdown of the insulation. Important parameters are, for example, the streamer radius and the streamer propagation length of arrested streamers. Such properties enter in breakdown prediction models. In the present study the streamer radius and the propagation length were investigated experimentally at 50 and 100 kPa for both polarities using strongly and weakly non-uniform background fields. No experimental information was available so far for negative polarity. The resulting streamer radius scaling agrees with previous experimental results for positive polarity and with expectations from breakdown models for negative polarity. These results were similar for strongly non-uniform and weakly non-uniform background fields. A difference between the two setups was observed for the streamer lengths. It was found that for strongly non-uniform fields the streamer length scales as expected with the critical electric field but with a different field for weakly non-uniform background fields. This was similar for both polarities.

  6. Conversion of radius of curvature to power (and vice versa)

    NASA Astrophysics Data System (ADS)

    Wickenhagen, Sven; Endo, Kazumasa; Fuchs, Ulrike; Youngworth, Richard N.; Kiontke, Sven R.

    2015-09-01

    Manufacturing optical components relies on good measurements and specifications. One of the most precise measurements routinely required is the form accuracy. In practice, form deviation from the ideal surface is effectively low frequency errors, where the form error most often accounts for no more than a few undulations across a surface. These types of errors are measured in a variety of ways including interferometry and tactile methods like profilometry, with the latter often being employed for aspheres and general surface shapes such as freeforms. This paper provides a basis for a correct description of power and radius of curvature tolerances, including best practices and calculating the power value with respect to the radius deviation (and vice versa) of the surface form. A consistent definition of the sagitta is presented, along with different cases in manufacturing that are of interest to fabricators and designers. The results make clear how the definitions and results should be documented, for all measurement setups. Relationships between power and radius of curvature are shown that allow specifying the preferred metric based on final accuracy and measurement method. Results shown include all necessary equations for conversion to give optical designers and manufacturers a consistent and robust basis for decision-making. The paper also gives guidance on preferred methods for different scenarios for surface types, accuracy required, and metrology methods employed.

  7. Distal anastomotic intimal hyperplasia: histopathologic character and biogenesis.

    PubMed

    Sottiurai, V S; Yao, J S; Batson, R C; Sue, S L; Jones, R; Nakamura, Y A

    1989-01-01

    Although thrombogenicity of the prosthetic graft, progression of the atherosclerotic disease and distal anastomotic intimal hyperplasia are known etiologic factors of late graft failure, its occurrence is frequently encountered in the late graft occlusion. Forth-two canine PTFE iliofemoral grafts (all with end-to-side distal anastomosis) were studied. Computer digitization revealed that distal anastomotic intimal hyperplasia occurred exclusively at the heel and the toe of the graft and the floor of the host artery. The distal anastomotic intimal hyperplasia was 80-130 cells thick. Light microscopy and transmission electron microscopy revealed a similar architecture of interlamination of cellular elements and extracellular matrix in the hyperplastic cells. Transmission electron microscopy further defined a gradual cell transformation and orientation from the graft to the lumen. The cells near the graft were characterized by a gradual reduction of rough endoplasmic reticulum with a concomitant acquisition of myofilaments, transforming ovoid mesenchymoid cells to slender myofibroblasts. The orientation of cells in distal anastomotic intimal hyperplasia was embodied by random cell distribution at the periphery to a well-organized interlamination of myofibroblasts and extracellular matrix near the lumen. Distal anastomotic intimal hyperplasia is a biologic entity with active cellular and subcellular events. Its biogenesis appears to be influenced by the hemodynamics of blood flow at the distal anastomosis. PMID:2713229

  8. The distal radioulnar joint. Anatomic and functional considerations.

    PubMed

    Kauer, J M

    1992-02-01

    The distal radioulnar joint is functionally coupled with the proximal radioulnar joint, thus forming a mechanism for the longitudinal rotation of the hand. Distal radioulnar mobility is derived from the geometry of the joint, joint surfaces, and radioulnar connections. There is a structural and functional separation between the distal radioulnar and carpal joints, giving the possibility of pronation and supination in every position of the hand to the forearm. As for the stability of the joints involved, the ulnar articular disk plays an essential role. Being part of both distal radioulnar and carpal joints, the disk has very specific morphologic features that not only are individualized to the function of both joints but also stabilize the joints in their independent movements. Developmental data give the strong impression of an architectural scheme, of which the distal radioulnar joint is only a part. Traumatic lesions at the distal radioulnar joint and disturbances in normal distal radioulnar alignment have to be viewed, therefore, in a wider context. PMID:1735231

  9. Distal Insertions of the Biceps Femoris

    PubMed Central

    Branch, Eric A.; Anz, Adam W.

    2015-01-01

    Background: Avulsion of the biceps femoris from the fibula and proximal tibia is encountered in clinical practice. While the anatomy of the primary posterolateral corner structures has been qualitatively and quantitatively described, a quantitative analysis regarding the insertions of the biceps femoris on the fibula and proximal tibia is lacking. Purpose: To quantitatively assess the insertions of the biceps femoris, fibular collateral ligament (FCL), and anterolateral ligament (ALL) on the fibula and proximal tibia as well as establish relationships among these structures and to pertinent surgical anatomy. Study Design: Descriptive laboratory study. Methods: Dissections were performed on 12 nonpaired, fresh-frozen cadaveric specimens identifying the biceps femoris, FCL, and ALL, and their insertions on the proximal tibia and fibula. The footprint areas, orientations, and distances from relevant osseous landmarks were measured using a 3-dimensional coordinate measurement device. Results: Dissection produced 6 easily identifiable and reproducible anatomic footprints. Tibial footprints included the insertion of the ALL and an insertion of the biceps femoris (TBF). Fibular footprints included the insertion of the FCL, a distal insertion of the biceps femoris (DBF), a medial footprint of the biceps femoris (MBF), and a proximal footprint of the biceps femoris (PBF). The mean area of these footprints (95% CI) was as follows: ALL, 53.0 mm2 (38.4-67.6); TBF, 93.9 mm2 (72.0-115.8); FCL, 86.8 mm2 (72.3-101.2); DBF, 119 mm2 (91.1-146.9); MBF, 46.8 mm2 (29.0-64.5); and PBF, 215 mm2 (192.4-237.5). The mean distance (95% CI) from the Gerdy tubercle to the center of the ALL footprint was 24.3 mm (21.6-27.0) and to the center of the TBF was 22.5 mm (21.0-24.0). The center of the DBF was 8.68 mm (7.0-10.3) from the anterior border of the fibula, the center of the FCL was 14.6 mm (12.5-16.7) from the anterior border of the fibula and 20.7 mm (19.0-22.4) from the tip of the fibular

  10. The learning curve in robotic distal pancreatectomy.

    PubMed

    Napoli, Niccolò; Kauffmann, Emanuele F; Perrone, Vittorio Grazio; Miccoli, Mario; Brozzetti, Stefania; Boggi, Ugo

    2015-09-01

    No data are available on the learning curve in robotic distal pancreatectomy (RADP). The learning curve in RADP was assessed in 55 consecutive patients using the cumulative sum method, based on operative time. Data were extracted from a prospectively maintained database and analyzed retrospectively considering all events occurring within 90 days of surgery. No operation was converted to laparoscopic or open surgery and no patient died. Post-operative complications occurred in 34 patients (61.8%), being of Clavien-Dindo grade I-II in 32 patients (58.1%), including pancreatic fistula in 29 patients (52.7%). No grade C pancreatic fistula occurred. Four patients received blood transfusions (7.2%), three were readmitted (5.4%) and one required repeat surgery (1.8%). Based on the reduction of operative times (421.1 ± 20.5 vs 248.9 ± 9.3 min; p < 0.0001), completion of the learning curve was achieved after ten operations. Operative time of the first 10 operations was associated with a positive slope (0.47 + 1.78* case number; R (2) 0.97; p < 0.0001*), while that of the following 45 procedures showed a negative slope (23.52 - 0.39* case number; R (2) 0.97; p < 0.0001*). After completion of the learning curve, more patients had a malignant histology (0 vs 35.6%; p = 0.002), accounting for both higher lymph node yields (11.1 ± 12.2 vs 20.9 ± 18.5) (p = 0.04) and lower rate of spleen preservation (90 vs 55.6%) (p = 0.04). RADP was safely feasible in selected patients and the learning curve was completed after ten operations. Improvement in clinical outcome was not demonstrated, probably because of the limited occurrence of outcome comparators.

  11. The learning curve in robotic distal pancreatectomy.

    PubMed

    Napoli, Niccolò; Kauffmann, Emanuele F; Perrone, Vittorio Grazio; Miccoli, Mario; Brozzetti, Stefania; Boggi, Ugo

    2015-09-01

    No data are available on the learning curve in robotic distal pancreatectomy (RADP). The learning curve in RADP was assessed in 55 consecutive patients using the cumulative sum method, based on operative time. Data were extracted from a prospectively maintained database and analyzed retrospectively considering all events occurring within 90 days of surgery. No operation was converted to laparoscopic or open surgery and no patient died. Post-operative complications occurred in 34 patients (61.8%), being of Clavien-Dindo grade I-II in 32 patients (58.1%), including pancreatic fistula in 29 patients (52.7%). No grade C pancreatic fistula occurred. Four patients received blood transfusions (7.2%), three were readmitted (5.4%) and one required repeat surgery (1.8%). Based on the reduction of operative times (421.1 ± 20.5 vs 248.9 ± 9.3 min; p < 0.0001), completion of the learning curve was achieved after ten operations. Operative time of the first 10 operations was associated with a positive slope (0.47 + 1.78* case number; R (2) 0.97; p < 0.0001*), while that of the following 45 procedures showed a negative slope (23.52 - 0.39* case number; R (2) 0.97; p < 0.0001*). After completion of the learning curve, more patients had a malignant histology (0 vs 35.6%; p = 0.002), accounting for both higher lymph node yields (11.1 ± 12.2 vs 20.9 ± 18.5) (p = 0.04) and lower rate of spleen preservation (90 vs 55.6%) (p = 0.04). RADP was safely feasible in selected patients and the learning curve was completed after ten operations. Improvement in clinical outcome was not demonstrated, probably because of the limited occurrence of outcome comparators. PMID:25990666

  12. Quantitative shape measurements of distal volcanic ash

    NASA Astrophysics Data System (ADS)

    Riley, Colleen M.; Rose, William I.; Bluth, Gregg J. S.

    2003-10-01

    Large-scale volcanic eruptions produce fine ash (<200 μm) which has a long atmospheric residence time (1 hour or more) and can be transported great distances from the volcanic source, thus, becoming a hazard to aircraft and public health. Ash particles have irregular shapes, so data on particle shape, size, and terminal velocities are needed to understand how the irregular-shaped particles affect transport processes and radiative transfer measurements. In this study, a methodology was developed to characterize particle shapes, sizes, and terminal velocities for three ash samples of different compositions. The shape and size of 2500 particles from (1) distal fallout (˜100 km) of the 14 October 1974 Fuego eruption (basaltic), (2) the secondary maxima (˜250 km) of the 18 August 1992 Spurr eruption (andesitic), and (3) the Miocene Ash Hollow member, Nebraska (rhyolitic) were measured using image analysis techniques. Samples were sorted into 10 to 19 terminal velocity groups (0.6-59.0 cm/s) using an air elutriation device. Grain-size distributions for the samples were measured using laser diffraction. Aspect ratio, feret diameter, and perimeter measurements were found to be the most useful descriptors of how particle shape affects terminal velocity. These measurement values show particle shape differs greatly from a sphere (commonly used in models and algorithms). The diameters of ash particles were 10-120% larger than ideal spheres at the same terminal velocity, indicating that irregular particle shape greatly increases drag. Gas-adsorption derived surface areas are 1 to 2 orders of magnitude higher than calculated surface areas based on measured dimensions and simple geometry, indicating that particle shapes are highly irregular. Correction factors for surface area were derived from the ash sample measurements so that surface areas calculated by assuming spherical particle shapes can be corrected to reflect more realistic values.

  13. An alternative method of osteosynthesis for distal humeral shaft fractures.

    PubMed

    Levy, Jonathan C; Kalandiak, Steven P; Hutson, James J; Zych, Gregory

    2005-01-01

    Treatment of extra-articular distal humerus shaft fractures with plating techniques is often difficult, as traditional centrally located posterior plates often encroach on the olecranon fossa, limiting distal osseous fixation. The use of a modified Synthes Lateral Tibial Head Buttress Plate (Synthes, Paoli, PA) allows for a centrally placed posterior plating of the humeral shaft that angles anatomically along the lateral column to treat far distal humeral shaft fractures. Fifteen patients treated in this manner were followed to radiographic and clinical union. There were no cases of instrumentation failure or loss of reduction.

  14. Hyperammonaemia in a child with distal renal tubular acidosis.

    PubMed

    Seracini, D; Poggi, G M; Pela, I

    2005-11-01

    A 5-month-old girl with distal renal tubular acidosis (RTA) and hyperammonaemia that had lasted for 12 days, despite metabolic acidosis correction, is presented in this report. The patient showed failure to thrive, poor feeding, hypotonia and vomiting crisis in absence of inborn errors of metabolism. Probably, hyperammonaemia was the result of an imbalance between the increased ammonia synthesis, in response to metabolic acidosis, and the impaired ammonia excretion, typical of distal RTA. Our case confirms that hyperammonaemia may be observed in distal RTA, mimicking an inborn error of metabolism, and it underlines that hyperammonaemia may persist several days after metabolic acidosis correction. PMID:16133056

  15. Quantitative, Comparative Assessment of Gait Between Single-Radius and Multi-Radius Total Knee Arthroplasty Designs.

    PubMed

    Larsen, Bethany; Jacofsky, Marc C; Jacofsky, David J

    2015-06-01

    Gait of single-radius (SR, n=16) and multi-radius (MR, n=16) posterior stabilized total knee arthroplasties was compared, along with controls (n=16), pre-op and 1 year post-op. Computer navigation and standard order sets controlled confounding variables. Post-operatively, SR knees did not differ from controls while MR knees continued to differ in important knee kinetic and kinematic properties. MR knees remained more extended (P=0.019) and had decreased power absorption (P=0.0001) during weight acceptance compared to the SR knees. Both surgical groups had similar KSS for Knee Scores (P=0.22) and Function Scores (P=0.58). The significant biomechanical differences are likely influenced by patella-femoral moment arm geometry and changing ligament laxity throughout the active range of motion.

  16. The Pronator Quadratus and Distal Anterior Interosseous Nerve: A Cadaveric Study

    PubMed Central

    Hinds, Richard M.; Gottschalk, Michael B.; Capo, John T.

    2015-01-01

    Background The pronator quadratus (PQ) muscle is an important and commonly encountered structure in surgery of the wrist. A thorough understanding of the anatomy of the PQ and the anterior interosseous nerve (AIN), which innervates the PQ, is important, particularly during distal radius fracture osteosynthesis and distal AIN transfer to deep branch of the ulnar nerve. Furthermore, there is a paucity of literature regarding sex differences in the morphology of these structures. We describe the morphology of the PQ and AIN and compare PQ and AIN findings in male and female specimens. Methods Twenty-five cadaveric upper extremities underwent loupe-aided dissection of the volar forearm with identification of the AIN and PQ. A digital photograph taken perpendicular to the volar surface of the forearm was used to measure the PQ and assess AIN morphology using ImageJ (National Institutes of Health; Bethesda, MD). Comparisons between male and female specimens were performed. Results Of the 25 specimens, 84% appeared as a single trapezoidal muscle bundle, with the remaining 16% demonstrating a double-bundle morphology. The PQ was a mean 3.8 ± 0.5 cm in radial-ulnar width and 4.6 ± 0.7 cm in proximal-distal length with a mean thickness, area, and volume of 0.6 ± 0.2 cm, 18.2 ± 4.8 cm2, and 10.5 ± 3.7 cm3, respectively. The PQ branch of the AIN was a mean 3.8 ± 1.1 cm long and had a mean diameter of 1.4 ± 0.2 mm. Male specimens demonstrated significantly greater radial-ulnar width (p = 0.005), area (p = 0.006), and volume (p = 0.033) of the PQ, as well as a greater distance from the radial styloid to the distal arborization of the AIN (p = 0.005) compared with female specimens. Conclusions The current study informs hand surgeons of the morphologic variability and sexual dimorphism of the PQ and AIN and may help guide operative planning. PMID:26261744

  17. Distal Triceps Knotless Anatomic Footprint Repair: A New Technique

    PubMed Central

    Paci, James M.; Clark, Jonathan; Rizzi, Angelo

    2014-01-01

    Distal triceps rupture is a rare injury causing significant disability. Several techniques for treating distal triceps ruptures have been described using bone tunnels or suture anchors. More recent techniques have focused on re-creating the anatomic footprint of the distal triceps tendon. However, the increasing numbers of anchors used increase the risk to the articular surface, and all earlier techniques require knot tying and bulky knots beneath the thin posterior elbow soft-tissue envelope. We describe a technique combining the use of bone tunnels and a single suture anchor to create a knotless anatomic footprint repair of the distal triceps. By using this technique, we are able to create a tension-band construct that self-reinforces the anatomic repair and is very low profile while significantly decreasing risk to the articular surface. PMID:25473618

  18. Distal Renal Tubular Acidosis in Infancy: A Bicarbonate Wasting State

    ERIC Educational Resources Information Center

    Rodriguez-Soriano, J.; And Others

    1975-01-01

    Studied were three unrelated infants with distal renal tubular acidosis (a condition characterized by an inability to acidify the urine to minimal pH levels resulting in the loss of bicarbonates). (DB)

  19. A distal airway foreign body removed with electromagnetic navigation bronchoscopy.

    PubMed

    Karpman, Craig; Midthun, David E; Mullon, John J

    2014-04-01

    Distal airway foreign bodies can be challenging to remove with a flexible bronchoscope because of angulation or deep impaction. Thoracic surgery may be required if bronchoscopy is not successful. The use of electromagnetic navigation for pulmonary nodule localization and characterization is well established; however, its use to localize and remove distal foreign bodies has not been described. We report the initial case of electromagnetic navigation-assisted foreign body removal.

  20. Comparison of Chevron and Distal Oblique Osteotomy for Bunion Correction.

    PubMed

    Scharer, Brandon M; DeVries, J George

    2016-01-01

    The chevron osteotomy is a standard procedure by which bunions are corrected. One of us routinely performs a distal oblique osteotomy, which, to the best of our knowledge, has not been described for the correction of bunion deformities. The purpose of the present study was to compare the short- and medium-term results of the distal oblique and chevron osteotomies for bunion correction. We performed a retrospective clinical and radiographic comparison of patients who had undergone a distal oblique or chevron osteotomy for the correction of bunion deformity. In addition, a prospective patient satisfaction survey was undertaken. A total of 55 patients were included in the present study and were treated from January 2012 to November 2014. Of the 55 patients, 27 (49.2%) were in the chevron group and 28 (50.8%) in the distal oblique group. Radiographically, no statistically significant difference was found between the 2 groups with respect to postoperative first intermetatarsal angle (p < .0001) and hallux valgus angle (p < .0001), but a greater change was found in the intermetatarsal angle in the distal oblique group (p = .467). Prospective patient satisfaction scores were available for 33 patients (60%), 16 (29%) in the chevron group and 17 (31%) in the distal oblique group. When converting the satisfaction score to a numerical score, the chevron group scored 3.3 ± 1.1 and the distal oblique group scored 3.2 ± 0.8 (p = .812). We found that the distal oblique osteotomy used in the present study is simple and reliable and showed radiographic correction and patient satisfaction equivalent to those in the chevron osteotomy. PMID:26972755

  1. Examination of ossification of the distal radial epiphysis using magnetic resonance imaging. New insights for age estimation in young footballers in FIFA tournaments.

    PubMed

    Schmidt, S; Vieth, V; Timme, M; Dvorak, J; Schmeling, A

    2015-03-01

    Alongside a variety of clinical and forensic issues, age determination in living persons also plays a decisive role in the field of professional sport. Only methods of determining skeletal age which do not expose individuals to ionizing radiation are suitable for this purpose. The present study examines whether MRI diagnosis of the distal radial epiphysis can be utilised to monitor internationally relevant age limits in professional football. The wrist area of 152 male footballers aged 18 to 22 years belonging to regional clubs was prospectively examined using MRI. The ossification stage of the distal radial epiphysis was subsequently determined on the basis of established criteria used in determining the maturity of the medial clavicular epiphysis. For the first time, we ascertained evidence of an increase in the prevalence of the phenomenon of threefold linear stratification (hypointense line, hyperintense line, and hypointense line) in the representation of the fused epiphyseal plate of the radius using magnetic resonance imaging with increasing chronological age. Within our study population, test persons with an ossified epiphyseal plate without any verifiable epiphyseal scar were not represented. The presumably high minimum age of entry into this final stage of development (>22 years) must be verified in the course of further studies. According to the results of the present study, the fused epiphyseal plate of the distal radius provides potential maturation criteria which appear suitable for reliable monitoring of all relevant age limits in international football with the aid of magnetic resonance imaging.

  2. The Arches Cluster: Extended Structure and Tidal Radius

    NASA Astrophysics Data System (ADS)

    Hosek, Matthew W., Jr.; Lu, Jessica R.; Anderson, Jay; Ghez, Andrea M.; Morris, Mark R.; Clarkson, William I.

    2015-11-01

    At a projected distance of ˜26 pc from Sgr A*, the Arches cluster provides insight into star formation in the extreme Galactic center (GC) environment. Despite its importance, many key properties, such as the cluster’s internal structure and orbital history, are not well known. We present an astrometric and photometric study of the outer region of the Arches cluster (R > 6.″25) using Hubble Space Telescope WFC3IR. Using proper motions, we calculate membership probabilities for stars down to F153M = 20 mag (˜2.5 M⊙) over a 120″ × 120″ field of view, an area 144 times larger than previous astrometric studies of the cluster. We construct the radial profile of the Arches to a radius of 75″ (˜3 pc at 8 kpc), which can be well described by a single power law. From this profile we place a 3σ lower limit of 2.8 pc on the observed tidal radius, which is larger than the predicted tidal radius (1-2.5 pc). Evidence of mass segregation is observed throughout the cluster, and no tidal tail structures are apparent along the orbital path. The absence of breaks in the profile suggests that the Arches has not likely experienced its closest approach to the GC between ˜0.2 and 1 Myr ago. If accurate, this constraint indicates that the cluster is on a prograde orbit and is located in front of the sky plane that intersects Sgr A*. However, further simulations of clusters in the GC potential are required to interpret the observed profile with more confidence.

  3. HABITABILITY OF EXOMOONS AT THE HILL OR TIDAL LOCKING RADIUS

    SciTech Connect

    Hinkel, Natalie R.; Kane, Stephen R.

    2013-09-01

    Moons orbiting extrasolar planets are the next class of object to be observed and characterized for possible habitability. Like the host-planets to their host-star, exomoons have a limiting radius at which they may be gravitationally bound, or the Hill radius. In addition, they also have a distance at which they will become tidally locked and therefore in synchronous rotation with the planet. We have examined the flux phase profile of a simulated, hypothetical moon orbiting at a distant radius around the confirmed exoplanets {mu} Ara b, HD 28185 b, BD +14 4559 b, and HD 73534 b. The irradiated flux on a moon at its furthest, stable distance from the planet achieves its largest flux gradient, which places a limit on the flux ranges expected for subsequent (observed) moons closer in orbit to the planet. We have also analyzed the effect of planetary eccentricity on the flux on the moon, examining planets that traverse the habitable zone either fully or partially during their orbit. Looking solely at the stellar contributions, we find that moons around planets that are totally within the habitable zone experience thermal equilibrium temperatures above the runaway greenhouse limit, requiring a small heat redistribution efficiency. In contrast, exomoons orbiting planets that only spend a fraction of their time within the habitable zone require a heat redistribution efficiency near 100% in order to achieve temperatures suitable for habitability. This means that a planet does not need to spend its entire orbit within the habitable zone in order for the exomoon to be habitable. Because the applied systems comprise giant planets around bright stars, we believe that the transit detection method is most likely to yield an exomoon discovery.

  4. Distal Locking Screws for Intramedullary Nailing of Tibial Fractures.

    PubMed

    Agathangelidis, Filon; Petsatodis, Georgios; Kirkos, John; Papadopoulos, Pericles; Karataglis, Dimitrios; Christodoulou, Anastasios

    2016-01-01

    Recently introduced tibial intramedullary nails allow a number of distal screws to be used to reduce the incidence of malalignment and loss of fixation of distal metaphyseal fractures. However, the number of screws and the type of screw configuration to be used remains obscure. This biomechanical study was performed to address this question. Thirty-six Expert tibial nails (Synthes, Oberdorf, Switzerland) were introduced in composite bone models. The models were divided into 4 groups with different distal locking configurations ranging from 2 to 4 screws. A 7-mm gap osteotomy was performed 72 mm from the tibial plafond to simulate a 42-C3 unstable distal tibial fracture. Each group was divided in 3 subgroups and underwent nondestructive biomechanical testing in axial compression, coronal bending, and axial torsion. The passive construct stiffness was measured and statistically analyzed with one-way analysis of variance. Although some differences were noted between the stiffness of each group, these were not statistically significant in compression (P=.105), bending (P=.801), external rotation (P=.246), and internal rotation (P=.370). This in vitro study showed that, when using the Expert tibial nail for unstable distal tibial fractures, the classic configuration of 2 parallel distal screws could provide the necessary stability under partial weight-bearing conditions. PMID:26840700

  5. [Epidemiology and management of isolated distal deep venous thrombosis].

    PubMed

    Galanaud, J-P; Kahn, S R; Khau Van Kien, A; Laroche, J-P; Quéré, I

    2012-12-01

    Isolated distal deep-vein thromboses (DVT) are infra-popliteal DVT without involvement of proximal veins or pulmonary embolism (PE). They can affect deep calf (tibial anterior, tibial posterior, or peroneal) or muscular (gastrocnemius or soleal) veins. They represent half of all lower limbs DVT. Proximal and distal DVTs differ in terms of risk factor profile, proximal DVT being more frequently associated with chronic risk factors and distal DVT with transient ones. Their natural history (rate of spontaneous proximal extension) is debated leading to uncertainties on the need to diagnose and treat them with anticoagulant drugs. In the long term, the risk of venous thromboembolic recurrence is lower than that of proximal DVT and their absolute risk of post-thrombotic syndrome is unknown. French national guidelines suggest treating with anticoagulants for 6 weeks a first episode of isolated distal DVT provoked by a transient risk factor and treating for at least 3 months unprovoked or recurrent or active cancer-related distal DVT. The use of compression stockings use is suggested in case of deep calf vein thrombosis. Ongoing therapeutic trials should provide important data necessary to establish an evidence-based mode of care, especially about the need to treat distal DVT at low risk of extension with anticoagulants.

  6. Experimental Method for Microbubbles Dynamics Monitoring and Radius Sizing

    NASA Astrophysics Data System (ADS)

    Fouan, Damien; Achaoui, Younes; Payan, Cedric; Mensah, Serge

    Rationale and aim: Within the context of divers' decompression illness prevention, ultrasonic detection and sizing of circulating microbubbles in blood is of great interest. In order to be representative of the divers gas tension level (supersaturation) and thus, to optimize decompression stages, the measurements (made in the right ventricle region) should be performed during a short period of time (ventricle filling <20 ms), efficient to detect a broad range of bubbles' radii population (radius from 20 to 200 _m) and harmless (Mechanical Index MI<0.3).

  7. Method and apparatus for logging short radius horizontal drainholes

    SciTech Connect

    Taylor, D.E.

    1991-04-30

    This patent describes an apparatus for use in logging a short radius horizontal drainhole. It comprises: a tubing string having a low portion; the lower portion of the tubing string including sensor support means therein; the lower portion of the tubing string containing openings communicating with the interior thereof in the vicinity of the sensor support means to thereby exposed the interior to the pressure and temperature conditions of the horizontal drainhole; and the lower portion of the tubing string including an end portion extending transversely of the tubing sting.

  8. Concentration at a radius for Hardy class functions

    NASA Astrophysics Data System (ADS)

    Kelly, Brian P.

    2007-03-01

    In this paper we establish the fundamental properties of concentration at a radius for functions in the classical Hardy space on the unit disk. For f(z) which is not identically zero and given r, 0

  9. Pion loop contribution to the electromagnetic pion charge radius

    SciTech Connect

    Roberts, C.D.; Bender, A.; Alkofer, R.

    1995-08-01

    There is a widely held misconception, based on a misrepresentation of the application of chiral perturbation theory, that the electromagnetic structure of the pion is dominated by the pion`s own pion-cloud. To clarify this the Global Color-symmetry Model (GCM), was used to calculate the electromagnetic charge radius of the pion. In this calculation the contributions from the quark core and pion loop were identified and compared. It was shown explicitly that the divergence of the charge radius in the chiral limit is due solely to the pion loop and that, at the physical value of the pion mass, this loop contributes less than 15% {l_angle}r{sub {pi}}{sup 2}{r_angle}; i.e. the quark core is the dominant determining characteristic for the pion. This suggests that quark-based models that fail to reproduce the m{sub {pi}} divergence of {l_angle}{sub {pi}}{sup 2}{r_angle} nevertheless incorporate the dominant characteristic of the pion: its quark core. The result`s studylend further support to the contention that, away from resonances, the dominant determining characteristic of kinematic and dynamical properties of hadrons is their quark core. A paper describing this work was submitted for publication.

  10. Automated bone age assessment of older children using the radius

    NASA Astrophysics Data System (ADS)

    Tsao, Sinchai; Gertych, Arkadiusz; Zhang, Aifeng; Liu, Brent J.; Huang, Han K.

    2008-03-01

    The Digital Hand Atlas in Assessment of Skeletal Development is a large-scale Computer Aided Diagnosis (CAD) project for automating the process of grading Skeletal Development of children from 0-18 years of age. It includes a complete collection of 1,400 normal hand X-rays of children between the ages of 0-18 years of age. Bone Age Assessment is used as an index of skeletal development for detection of growth pathologies that can be related to endocrine, malnutrition and other disease types. Previous work at the Image Processing and Informatics Lab (IPILab) allowed the bone age CAD algorithm to accurately assess bone age of children from 1 to 16 (male) or 14 (female) years of age using the Phalanges as well as the Carpal Bones. At the older ages (16(male) or 14(female) -19 years of age) the Phalanges as well as the Carpal Bones are fully developed and do not provide well-defined features for accurate bone age assessment. Therefore integration of the Radius Bone as a region of interest (ROI) is greatly needed and will significantly improve the ability to accurately assess the bone age of older children. Preliminary studies show that an integrated Bone Age CAD that utilizes the Phalanges, Carpal Bones and Radius forms a robust method for automatic bone age assessment throughout the entire age range (1-19 years of age).

  11. Artificial gravity: head movements during short-radius centrifugation

    NASA Technical Reports Server (NTRS)

    Young, L. R.; Hecht, H.; Lyne, L. E.; Sienko, K. H.; Cheung, C. C.; Kavelaars, J.

    2001-01-01

    Short-radius centrifugation is a potential countermeasure to long-term weightlessness. Unfortunately, head movements in a rotating environment induce serious discomfort, non-compensatory vestibulo-ocular reflexes, and subjective illusions of body tilt. In two experiments we investigated the effects of pitch and yaw head movements in participants placed supine on a rotating bed with their head at the center of rotation, feet at the rim. The vast majority of participants experienced motion sickness, inappropriate vertical nystagmus and illusory tilt and roll as predicted by a semicircular canal model. However, a small but significant number of the 28 participants experienced tilt in the predicted plane but in the opposite direction. Heart rate was elevated following one-second duration head turns. Significant adaptation occurred following a series of head turns in the light. Vertical nystagmus, motion sickness and illusory tilt all decreased with adaptation. Consequences for artificial gravity produced by short-radius centrifuges as a countermeasure are discussed. Grant numbers: NCC 9-58. c 2001. Elsevier Science Ltd. All rights reserved.

  12. Distal antenna and distal antenna related encode nuclear proteins containing pipsqueak motifs involved in antenna development in Drosophila.

    PubMed

    Emerald, B Starling; Curtiss, Jennifer; Mlodzik, Marek; Cohen, Stephen M

    2003-03-01

    Legs and antennae are considered to be homologous appendages. The fundamental patterning mechanisms that organize spatial pattern are conserved, yet appendages with very different morphology develop. A genetic hierarchy for specification of antennal identity has been partly elucidated. We report identification of a novel family of genes with roles in antennal development. The distal antenna (dan) and distal antenna-related (danr) genes encode novel nuclear proteins that are expressed in the presumptive distal antenna, but not in the leg imaginal disc. Ectopic expression of dan or danr causes partial transformation of distal leg structure toward antennal identity. Mutants that remove dan and danr activity cause partial transformation of antenna toward leg identity. Therefore we suggest that dan and danr contribute to differentiation of antenna-specific characteristics. Antenna-specific expression of dan and danr depends on a regulatory hierarchy involving homothorax and Distal-less, as well as cut and spineless. We propose that dan and danr are effector genes that act downstream of these genes to control differentiation of distal antennal structures.

  13. Autoxidation of oxymyoglobin with the distal (E7) glutamine.

    PubMed

    Suzuki, T

    1987-08-01

    We reported previously that the distal(E7) histidine is replaced by glutamine in myoglobin from the shark, Galeorhinus japonicus. The amino-acid sequence of myoglobin from another shark, Heterodontus japonicus, has been determined. The myoglobin is composed of 148 residues, is acetylated at the N-terminus, and contains the distal(E7) histidine at position 59. Although the sequence homologies between G. japonicus, H. japonicus, and sperm-whale myoglobins were about 40-55%, their hydropathy profiles were very similar, indicating that they have a similar geometry in their globin folding. The autoxidation rates of the two shark oxymyoglobins were examined in 0.1 M buffer at 25 degrees C over pH range 4.5-11.5. The pH dependence for the autoxidation of H. japonicus myoglobin was very similar to that of sperm-whale myoglobin, although the rate was about 10-times higher over the pH range examined. In both myoglobins, autoxidation was largely accelerated by H+. On the other hand, the pH dependence of G. japonicus myoglobin, which has the distal glutamine in the place of histidine, was quite different from those of sperm-whale and H. japonicus myoglobins. One of the most remarkable features is the fact that the autoxidation rate is not enhanced with an increase in the concentration of H+ in the acidic range of pH, where the autoxidation of sperm-whale and H. japonicus myoglobins is most accelerated. This finding suggests that the distal(E7) histidine participates in the autoxidation reaction as a catalytic residue facilitating the movement of a catalytic proton.

  14. Bone Strength and Structural Deficits in Children and Adolescents With a Distal Forearm Fracture Resulting From Mild Trauma

    PubMed Central

    Farr, Joshua N; Amin, Shreyasee; Melton, L Joseph; Kirmani, Salman; McCready, Louise K; Atkinson, Elizabeth J; Müller, Ralph; Khosla, Sundeep

    2014-01-01

    Although distal forearm fractures (DFFs) are common during childhood and adolescence, it is unclear whether they reflect underlying skeletal deficits or are simply a consequence of the usual physical activities, and associated trauma, during growth. Therefore, we examined whether a recent DFF, resulting from mild or moderate trauma, is related to deficits in bone strength and cortical and trabecular bone macro- and microstructure compared with nonfracture controls. High-resolution peripheral quantitative computed tomography was used to assess micro-finite element-derived bone strength (ie, failure load) and to measure cortical and trabecular bone parameters at the distal radius and tibia in 115 boys and girls with a recent (<1 year) DFF and 108 nonfracture controls aged 8 to 15 years. Trauma levels (mild versus moderate) were assigned based on a validated classification scheme. Compared with sex-matched controls, boys and girls with a mild-trauma DFF (eg, fall from standing height) showed significant deficits at the distal radius in failure load (−13% and −11%, respectively; p<0.05) and had higher (“worse”) fall load-to-strength ratios (both þ10%; p<0.05 for boys and p=0.06 for girls). In addition, boys and girls with a mild-trauma DFF had significant reductions in cortical area (−26% and −23%, respectively; p<0.01) and cortical thickness (−14% and −13%, respectively; p<0.01) compared with controls. The skeletal deficits in the mild-trauma DFF patients were generalized, as similar changes were present at the distal tibia. By contrast, both boys and girls with a moderate-trauma DFF (eg, fall from a bicycle) had virtually identical values for all of the measured bone parameters compared with controls. In conclusion, DFFs during growth have two distinct etiologies: those owing to underlying skeletal deficits leading to fractures with mild trauma versus those owing to more significant trauma in the setting of normal bone strength. PMID:23959563

  15. An intrinsic timer specifies distal structures of the vertebrate limb

    PubMed Central

    Saiz-Lopez, Patricia; Chinnaiya, Kavitha; Campa, Victor M.; Delgado, Irene; Ros, Maria A.; Towers, Matthew

    2015-01-01

    How the positional values along the proximo-distal axis (stylopod-zeugopod-autopod) of the limb are specified is intensely debated. Early work suggested that cells intrinsically change their proximo-distal positional values by measuring time. Recently, however, it is suggested that instructive extrinsic signals from the trunk and apical ectodermal ridge specify the stylopod and zeugopod/autopod, respectively. Here, we show that the zeugopod and autopod are specified by an intrinsic timing mechanism. By grafting green fluorescent protein-expressing cells from early to late chick wing buds, we demonstrate that distal mesenchyme cells intrinsically time Hoxa13 expression, cell cycle parameters and the duration of the overlying apical ectodermal ridge. In addition, we reveal that cell affinities intrinsically change in the distal mesenchyme, which we suggest results in a gradient of positional values along the proximo-distal axis. We propose a complete model in which a switch from extrinsic signalling to intrinsic timing patterns the vertebrate limb. PMID:26381580

  16. Implant Size Availability Affects Reproduction of Distal Femoral Anatomy.

    PubMed

    Morris, William Z; Gebhart, Jeremy J; Goldberg, Victor M; Wera, Glenn D

    2016-07-01

    A total knee arthroplasty system offers more distal femoral implant anterior-posterior (AP) sizes than its predecessor. The purpose of this study is to investigate the impact of increased size availability on an implant system's ability to reproduce the AP dimension of the native distal femur. We measured 200 cadaveric femora with the AP-sizing guides of Zimmer (Warsaw, IN) NexGen (8 sizes) and Zimmer Persona (12 sizes) total knee arthroplasty systems. We defined "size deviation" as the difference in the AP dimension between the anatomic size of the native femur and the closest implant size. We defined satisfactory reproduction of distal femoral dimensions as < 1 mm difference between the implant and native femur size. The NexGen system was associated with a mean 0.46 mm greater implant size deviation than Persona (p < 0.001). When using a 1 mm size deviation as a cutoff for satisfactory replication of the native distal femoral anatomy, 85/200 specimens (42.5%) were a poor fit by NexGen, but a satisfactory fit by Persona. Only 1/200 specimens (0.5%) was a poor fit by Persona, but a satisfactory fit by NexGen (p < 0.001). The novel knee system with 12 versus 8 sizes reproduces the AP dimension of the native distal femur more closely than its predecessor. Further study is needed to determine the clinical impact of these differences.

  17. A New Orthodontic Appliance with a Mini Screw for Upper Molar Distalization

    PubMed Central

    2016-01-01

    The aim of this study is to present a new upper molar distalization appliance called Cise distalizer designed as intraoral device supported with orthodontic mini screw for upper permanent molar distalization. The new appliance consists of eight main components. In order to understand the optimum force level, the appliance under static loading is tested by using strain gage measurement techniques. Results show that one of the open coils produces approximately 300 gr distalization force. Cise distalizer can provide totally 600 gr distalization force. This range of force level is enough for distalization of upper first and second molar teeth. PMID:27528796

  18. Ejecta emplacement: from distal to proximal

    NASA Astrophysics Data System (ADS)

    Artemieva, N.

    2008-09-01

    Introduction Most part of impact ejecta is deposited ballistically at some distance from a crater, defined by ejection velocity V and ejection angle α: d=v2sinα/g. In case of giant impacts, planetary curvature should be taken into account [1]. Combined with ejecta scaling [2], these relations allow to define ejecta thickness as a function of distance. Ejecta from large craters are deposited at velocity high enough to mobilize substrate material and to thicken ejecta deposits [3]. Ballistic approximation is valid for airless bodies (if impact vaporization is not vast) or for proximal ejecta of large impact craters, where ejecta mass per unit area is substantially greater than the mass of involved vapor/atmosphere (M-ratio). Deposition of distal ejecta, in which ejecta mass is negligible compared to the atmosphere, may be also treated in a simplified manner, i.e. as 1) passive motion of ejected particles within an impact plume and 2) later, as sedimentation of particles in undisturbed atmosphere (equilibrium between gravity and drag). In all intermediate M-ratio values, impact ejecta move like a surge, i.e. dilute suspension current in which particles are carried in turbulent flows under the influence of gravity. Surges are well-known for near-surface explosive tests, described in detail for volcanic explosions (Plinian column collapse, phreato-magmatic eruption, lateral blast), and found in ejecta from the Chicxulub [4] and the Ries [5]. Important aspects of surge transport include its ability to deposit ejecta over a larger area than that typical of continuous ballistic ejecta and to create multiple ejecta layers. Numerical model Two-phase hydrodynamics. Surges should be modeled in the frame of two-phase hydrodynamics, i.e. interaction between solid/molten particles and atmospheric gas/impact vapor should be taken into account. There are two techniques of solving equations for dust particle motion in a gas flow. The first one describes solid/molten particles as a

  19. Radius of Curvature Measurements: An Independent Look at Accuracy Using Novel Optical Metrology

    NASA Technical Reports Server (NTRS)

    Taylor, Bryon; Kahan, Mark; Russell, Kevin (Technical Monitor)

    2002-01-01

    The AMSD (Advanced Mirror System Demonstrator) program mirror specifications include the ability to manufacture the mirror to a radius of curvature of 10 m +/- 1 mm and to control its radius at 30K to the same specification. Therefore, it is necessary for the Government Team to be able to measure mirror radius of curvature to an accuracy of better than 0.5 mm. This presentation discusses a novel optical metrology system for measuring radius of curvature.

  20. Finite Larmor radius effect on ion pickup at Venus

    NASA Technical Reports Server (NTRS)

    Phillips, J. L.; Luhmann, J. G.; Russell, C. T.; Moore, K. R.

    1987-01-01

    The interaction of the solar wind with Venus is influenced by the pickup of newly born exospheric oxygen ions by the convecting magnetosheath plasma. The flow and field configuration of the magnetosheath plasma, together with the large gyroradius of the pickup ions, cause mass loading to occur preferentially on one side of the magnetosheath. The observed hemispherical asymmetry in the magnetic field in the near-planet magnetosheath, attributed to this pickup process, is confirmed by direct observation of the picked-up planetary particles. Test particle calculations show that a current system created by ion pickup has the appropriate location and magnitude to account for the magnetic field asymmetry. The results indicate that a fluid treatment of the Venus mass-loading problem is not entirely appropriate; a hybrid or kinetic model is necessary to incorporate the finite Larmor radius of the pickup particles which produces the observed asymmetry.

  1. Heliocentric radius of the cosmic ray modulation boundary

    NASA Technical Reports Server (NTRS)

    Randall, B. A.; Van Allen, J. A.

    1986-01-01

    A semiempirical analysis is made of an extensive body of observed cosmic ray intensity data from Pioneers 10 and 11, and related spectral information from other authors, in order to infer the radius R of the modulation region surrounding the sun. During the period 1972-1985, the inferred values of R vary with time systematically and in a manner generally similar to that of sunspot numbers. The range of values of R is from 42 AU at the time of minimum solar activity (circa 1976) to 88 AU about 1.5 yr following the time of maximum solar activity (circa 1980). A specific, testable prediction is that Pioneer 10 will reach the modulation boundary in 1988, and will remain in its vicinity for several years thereafter.

  2. Inductive voltage adder (IVA) for submillimeter radius electron beam

    SciTech Connect

    Mazarakis, M.G.; Poukey, J.W.; Maenchen, J.E.

    1996-12-31

    The authors have already demonstrated the utility of inductive voltage adder accelerators for production of small-size electron beams. In this approach, the inductive voltage adder drives a magnetically immersed foilless diode to produce high-energy (10--20 MeV), high-brightness pencil electron beams. This concept was first demonstrated with the successful experiments which converted the linear induction accelerator RADLAC II into an IVA fitted with a small 1-cm radius cathode magnetically immersed foilless diode (RADLAC II/SMILE). They present here first validations of extending this idea to mm-scale electron beams using the SABRE and HERMES-III inductive voltage adders as test beds. The SABRE experiments are already completed and have produced 30-kA, 9-MeV electron beams with envelope diameter of 1.5-mm FWHM. The HERMES-III experiments are currently underway.

  3. Severely comminuted radius fracture presenting as a signature patterned injury.

    PubMed

    Jain, Saurabh; Rajan, Sunil; Srivastava, Abhishek

    2016-01-01

    Dilemma still prevails, regarding the exact management of mangled extremity injuries between limb salvage versus amputation, each having there own set of complications. We here present a case of severely comminuted fractures of radius (bag of bones) along with the multiple criss-cross shaped lacerated wounds on the forearm and wrist presenting as a "signature pattern injury" caused by entrapment of the limb in the concrete mixer. MESS score of patient was 8, a score valid for amputation, but contrary, we successfully salvaged the patient's limb with use of radio-carpal distracter. Management of mangled injuries should be individualized, with due consideration to the mechanism and force of injury, associated injuries, and the patient profile. PMID:27053813

  4. Inclusive jet spectrum for small-radius jets

    NASA Astrophysics Data System (ADS)

    Dasgupta, Mrinal; Dreyer, Frédéric A.; Salam, Gavin P.; Soyez, Gregory

    2016-06-01

    Following on our earlier work on leading-logarithmic (LL R ) resummations for the properties of jets with a small radius, R, we here examine the phenomenological considerations for the inclusive jet spectrum. We discuss how to match the NLO predictions with small- R resummation. As part of the study we propose a new, physically-inspired prescription for fixed-order predictions and their uncertainties. We investigate the R-dependent part of the next-to-next-to-leading order (NNLO) corrections, which is found to be substantial, and comment on the implications for scale choices in inclusive jet calculations. We also examine hadronisation corrections, identifying potential limitations of earlier analytical work with regards to their p t -dependence. Finally we assemble these different elements in order to compare matched (N)NLO+LLR predictions to data from ALICE and ATLAS, finding improved consistency for the R-dependence of the results relative to NLO predictions.

  5. Hydrodynamic radius fluctuations in model DNA-grafted nanoparticles

    NASA Astrophysics Data System (ADS)

    Vargas-Lara, Fernando; Starr, Francis W.; Douglas, Jack F.

    2016-05-01

    We utilize molecular dynamics simulations (MD) and the path-integration program ZENO to quantify hydrodynamic radius (Rh) fluctuations of spherical symmetric gold nanoparticles (NPs) decorated with single-stranded DNA chains (ssDNA). These results are relevant to understanding fluctuation-induced interactions among these NPs and macromolecules such as proteins. In particular, we explore the effect of varying the ssDNA-grafted NPs structural parameters, such as the chain length (L), chain persistence length (lp), NP core size (R), and the number of chains (N) attached to the nanoparticle core. We determine Rh fluctuations by calculating its standard deviation (σRh) of an ensemble of ssDNA-grafted NPs configurations generated by MD. For the parameter space explored in this manuscript, σR h shows a peak value as a function of N, the amplitude of which depends on L, lp and R, while the broadness depends on R.

  6. Severely comminuted radius fracture presenting as a signature patterned injury

    PubMed Central

    Jain, Saurabh; Rajan, Sunil; Srivastava, Abhishek

    2016-01-01

    Dilemma still prevails, regarding the exact management of mangled extremity injuries between limb salvage versus amputation, each having there own set of complications. We here present a case of severely comminuted fractures of radius (bag of bones) along with the multiple criss-cross shaped lacerated wounds on the forearm and wrist presenting as a “signature pattern injury” caused by entrapment of the limb in the concrete mixer. MESS score of patient was 8, a score valid for amputation, but contrary, we successfully salvaged the patient's limb with use of radio-carpal distracter. Management of mangled injuries should be individualized, with due consideration to the mechanism and force of injury, associated injuries, and the patient profile. PMID:27053813

  7. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic contact lens radius measuring device... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device...

  8. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic contact lens radius measuring device... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device...

  9. Maximum wind radius estimated by the 50 kt radius: improvement of storm surge forecasting over the western North Pacific

    NASA Astrophysics Data System (ADS)

    Takagi, Hiroshi; Wu, Wenjie

    2016-03-01

    Even though the maximum wind radius (Rmax) is an important parameter in determining the intensity and size of tropical cyclones, it has been overlooked in previous storm surge studies. This study reviews the existing estimation methods for Rmax based on central pressure or maximum wind speed. These over- or underestimate Rmax because of substantial variations in the data, although an average radius can be estimated with moderate accuracy. As an alternative, we propose an Rmax estimation method based on the radius of the 50 kt wind (R50). Data obtained by a meteorological station network in the Japanese archipelago during the passage of strong typhoons, together with the JMA typhoon best track data for 1990-2013, enabled us to derive the following simple equation, Rmax = 0.23 R50. Application to a recent strong typhoon, the 2015 Typhoon Goni, confirms that the equation provides a good estimation of Rmax, particularly when the central pressure became considerably low. Although this new method substantially improves the estimation of Rmax compared to the existing models, estimation errors are unavoidable because of fundamental uncertainties regarding the typhoon's structure or insufficient number of available typhoon data. In fact, a numerical simulation for the 2013 Typhoon Haiyan as well as 2015 Typhoon Goni demonstrates a substantial difference in the storm surge height for different Rmax. Therefore, the variability of Rmax should be taken into account in storm surge simulations (e.g., Rmax = 0.15 R50-0.35 R50), independently of the model used, to minimize the risk of over- or underestimating storm surges. The proposed method is expected to increase the predictability of major storm surges and to contribute to disaster risk management, particularly in the western North Pacific, including countries such as Japan, China, Taiwan, the Philippines, and Vietnam.

  10. Septic arthritis of the distal interphalangeal joint in 12 horses.

    PubMed

    Honnas, C M; Welch, R D; Ford, T S; Vacek, J R; Watkins, J P

    1992-01-01

    The medical records of 12 horses with septic arthritis of a distal interphalangeal joint were reviewed to determine clinical features and response to treatment. Sepsis was caused by trauma or an injection that resulted in an open or contaminated distal interphalangeal joint. All horses were severely lame. Treatment included broad-spectrum parenterally administered antimicrobial drugs (ten horses), percutaneous through-and-through joint lavage (eight horses), indwelling drains (three horses), immobilization of the limb in a cast (three horses), intraarticular injection of sodium hyaluronate (one horse), intraarticular injection of antimicrobial drugs (five horses), curettage of the distal phalanx (one horse), and cancellous bone grafting to promote fusion (one horse). Five horses were euthanatized. Ankylosis of the affected joint developed in five horses, four of which are pasture sound. Two horses treated medically are sound although one underwent subsequent palmar digital neurectomy for treatment of navicular syndrome.

  11. Molar distalization with the assistance of Temporary Anchorage Devices.

    PubMed

    Palencar, Adrian J

    2015-01-01

    This article describes efficient techniques for distalization of maxillary and mandibular molars with the assistance of Temporary Anchorage Devices (TADs). There are numerous occasions where the distalization of molars is required in lieu of the odontectomy of bicuspids. In the past, extra-oral force has been used, (i.e. Cervical or Combination Head Gear, or intra-oral force, i.e. Posterior Sagittal Appliance, Modified Greenfield Appliance, Williams DMJ 20001, CD Distalizer, Magill Sagittal, Pendulum Appliance, etc.). All the intra-oral appliances have a common denominator the orthodontic clinician has to deal with, the undesirable expression of the Third Law of Newton. The utilization of TADs allows us to circumvent this shortcoming, establishing an absolute anchorage, and thus completely negate the expression of the Third Law of Newton. PMID:25881377

  12. Dislocation of the distal phalanx epiphysis in toddlers.

    PubMed

    Waters, P M; Benson, L S

    1993-07-01

    Two cases of physeal fracture dislocation of the distal phalanx are reviewed. Each injury occurred in a toddler, was originally undiagnosed, and appeared years later as a dorsal mass in a fore-shortened digit with decreased distal interphalangeal joint motion. In each case x-ray films revealed a dislocated epiphysis, accounting for the enlarging dorsal prominence and the phalangeal growth disturbance. These cases demonstrate that dislocation of the distal phalanx epiphysis can occur with a crush injury and may be difficult to detect before development of the ossification center. Careful physical examination and a high index of suspicion will increase the likelihood of early diagnosis. Early open reduction may prevent the late complications of deformity and stiffness. PMID:8349960

  13. Mitochondrial dysfunction in distal axons contribute to HIV sensory neuropathy

    PubMed Central

    Lehmann, Helmar C.; Chen, Weiran; Borzan, Jasenka; Mankowski, Joseph; Höke, Ahmet

    2010-01-01

    Objective Accumulation of mitochondrial DNA (mtDNA) damage has been associated with aging and abnormal oxidative metabolism. We hypothesized that in human immunodeficiency virus associated sensory neuropathy (HIV-SN), damaged mtDNA accumulates in distal nerve segments and that a spatial pattern of mitochondrial dysfunction contribute to the distal degeneration of sensory nerve fibers. Methods We measured levels of common deletion mutations in mtDNA and expression levels of mitochondrial respiratory chain complexes of matched proximal and distal nerve specimens from patients with and without HIV-SN. In mitochondria isolated from peripheral nerves of simian immunodeficiency virus (SIV) infected macaques, a model of HIV-SN, we measured mitochondrial function and generation of reactive oxygen species. Results We identified increased levels of mtDNA common deletion mutation in post-mortem sural nerves of patients with HIV-SN as compared to uninfected patients or HIV patients without sensory neuropathy. Furthermore, we found that common deletion mutation in mtDNA was more prevalent in distal sural nerves compared to dorsal root ganglia. In a primate model of HIV-SN, freshly isolated mitochondria from sural nerves of macaques infected with a neurovirulent strain of SIV showed impaired mitochondrial function compared to mitochondria from proximal nerve segments. Interpretation Our findings suggest that mtDNA damage accumulates in distal mitochondria of long axons, especially in patients with HIV-SN, and that this may lead to reduced mitochondrial function in distal nerves relative to proximal segments. Although our findings are based on HIV-SN, if confirmed in other neuropathies, these observations could explain the length-dependent nature of most axonal peripheral neuropathies. PMID:21280080

  14. Reverse telescoping in distal skarns at Campiglia Marittima (Italy)

    NASA Astrophysics Data System (ADS)

    Vezzoni, Simone; Dini, Andrea; Rocchi, Sergio

    2014-05-01

    Skarn deposits commonly results from the metasomatic alteration of a rock, usually carbonate-rich, by infiltration of hydrothermal fluids. Most carbonate-hosted skarn deposits show a direct spatial relationship with magmatic intrusions and an intimate relationship with porphyry copper deposits. Their primary mineralogical and geochemical features indicate metasomatism by high-temperature magmatic fluids. Conversely, many distal Pb-Zn-Ag skarns pose an important challenge because there is no apparent association with magmatic intrusions and external, meteoric and/or basinal fluids should become increasingly dominant with increasing distance from the igneous source. Nevertheless recent investigation of distal skarn deposits indicates that ore-forming fluids match the composition of proximal magmatic fluids in granitoid-related mineral deposits. Besides that metal producer (Pb, Zn, Ag, Cu, Fe, W, Sn), skarn deposits can be key to understanding fluid dynamics at the periphery of magmatic-hydrothermal systems, unraveling pathways to hidden ore deposits (e.g porphyry copper). In this scenario, research on distal skarns opens new perspectives for deep mineral exploration and/or modeling of intrusion centered geothermal systems, because they should represent the outer limit of the hydrothermal system dominated by magmatic aqueous fluids. Here we present exceptional evidences from a distal Pb-Zn-Ag skarn deposit in Campiglia Marittima, Italy, where the magma, after having released the metasomatic fluids, fled up chasing its own fluid stream and invading large pockets of the newly formed skarn bodies at shallower level. Detailed underground mapping and petrologic data indicate that, after the formation of a typical distal Pb-Zn-Ag skarn, the intrusion of the parent magma produced prograde reactions in the skarn silicates, mobilization of the Pb-Zn-Ag sulfides and precipitation of a new Cu-Fe sulfide assemblage. This is a very unusual case of reverse telescoping during which

  15. Distal protection devices during percutaneous coronary and carotid interventions.

    PubMed

    Fasseas, Panayotis; Orford, James L; Denktas, Ali E; Berger, Peter B

    2001-01-01

    Distal embolization of particulate matter complicates percutaneous coronary and peripheral interventions more often than had been recognized until recently. A number of distal protection devices are under development. The PercuSurge GuardWiretrade mark is a balloon occlusion thrombectomy device approved by the United States Food and Drug Administration for saphenous vein graft intervention. A number of filter devices utilize an expandable filter mounted on the angioplasty guidewire to facilitate entrapment of particles and safe removal. The Parodi Anti-Emboli Systemtrade mark is an example of a catheter occlusion device that establishes protection by reversing blood flow in the target vessel.

  16. Galeazzi fracture with volar dislocation of the distal radioulnar joint.

    PubMed

    Kim, Suezie; Ward, James P; Rettig, Michael E

    2012-11-01

    Galeazzi fracture dislocations are fractures of the distal one-third of the radial diaphysis with traumatic disruption of the distal radioulnar joint (DRUJ). This injury results in subluxation or dislocation of the ulnar head. We present a case of a Galeazzi fracture with a volar dislocation of the DRUJ. Open reduction of the DRUJ with Kirschner wire fixation in pronation was necessary to reduce the joint and maintain anatomic alignment. Repair of the triangular fibrocartilage complex was also necessary to maintain stability of the DRUJ.

  17. Modified distal shoe appliance--fabrication and clinical performance.

    PubMed

    Gujjar, Kumar Raghav; Indushekar, K R; Amith, H V; Sharma, Shefali Li

    2012-01-01

    When the primary second molar is prematurely lost, mesial movement and migration of the permanent first molar often occurs. This is one of the most difficult problems of the developing dentition confronted by pediatric dentists. Use of a space maintainer that will guide the permanent first molar into its normal position is indicated. In cases with bilateral premature loss of primary molars, the conventional design of distal shoe poses a variety of problems and, therefore, necessitates a customized design for the eruption guidance of permanent first molars. The purpose of this case report is to discuss an innovative design of a distal shoe appliance, which was used with good clinical results.

  18. Failure of dual radius hydroxyapatite-coated acetabular cups

    PubMed Central

    D'Angelo, Fabio; Molina, Mauro; Riva, Giacomo; Zatti, Giovanni; Cherubino, Paolo

    2008-01-01

    Introduction Many kind of hydroxyapatite-coated cups were used, with favorable results in short term studies; it was supposed that its use could improve osteointegration of the cup, enhancing thus stability and survivorship. The purpose of this study is to analyze the long term behavior of the hemispheric HA coated, Dual Radius Osteonics cup and to discuss the way of failure through the exam of the revised components and of both periacetabular and osteolysis tissue. Materials and Methods Between 1994 and 1997, at the Department of Orthopedic Sciences of the Insubria University, using the posterolateral approach, were implanted 276 Dual Radius Osteonics® in 256 patients, with mean age of 63 years. Results At a mean follow-up of 10 years (range 8–12 years), 183 cups in 165 patients, were available for clinical and radiographical evaluation. 22 Cups among the 183 were revised (11%). The cause of revision was aseptic loosening in 17 cases, septic loosening in one case, periprosthetic fracture in another case, osteolysis and polyethylene wear in two cases and, finally, recurrent dislocations in the last one. In the remaining patients, mean HHS increased from a preoperative value of 50,15 to a postoperative value of 92,69. The mean polyethylene wear was 1,25 mm (min. 0,08, max. 3,9 mm), with a mean annual wear of 0,17 mm. The mean acetabular migration on the two axis was 1,6 mm and 1,8 mm. Peri-acetabular osteolysis were recorded in 89% of the implants (163 cases). The cumulative survivorship (revision as endpoint) at the time was 88,9%. Conclusion Our study confirms the bad behavior of this type of cup probably related to the design, to the method of HA fixation. The observations carried out on the revised cup confirm these hypotheses but did not clarify if the third body wear could be a further problem. Another interesting aspect is the high incidence of osteolysis, which are often asymptomatic becoming a problem for the surgeon as the patient refuses the

  19. The Relation Between Radius, Mass, and Incident Flux of Exoplanets

    NASA Astrophysics Data System (ADS)

    Weiss, Lauren M.; Marcy, G. W.; Rowe, J.; Isaacson, H. T.; Howard, A.; Fortney, J. J.; Miller, N.; Demory, B.; Fischer, D.; Adams, E. A.; Dupree, A. K.; Howell, S. B.; Horch, E.; Everett, M. E.; Seager, S.; Fabrycky, D. C.

    2013-01-01

    We measure the mass of a modestly irradiated giant or "warm Jupiter," KOI-94d, in order to calculate its density. We wish to determine whether this planet, which is in a 22 day orbit and receives 107 times as much incident flux as the Earth, is bloated like "hot Jupiters" or as dense as our own Jupiter. In addition to its warm Jupiter, KOI-94 hosts at least 3 smaller planets, all of which were detected through transits by the Kepler Mission. This presents the opportunity to characterize a multi-planet system and to test dynamic stability and formation theory through observations of the masses and orbital elements of these planets. With 26 radial velocity measurements of KOI-94 from the W. M. Keck Observatory/HIRES, we measure the mass of the giant planet and upper limits to the masses of the three smaller planets. Transit timing variations will allow us to hone the mass measurements of the three smaller planets. Using the KOI-94 system and all other planets with published values for both mass and radius, we establish two fundamental planes for exoplanets that relate their mass, incident flux, and radius from a few Earth masses up to ten Jupiter masses: log(Rp/RE) = 0.007 + 0.53 log(M/ME) - 0.001 log(F/[erg/s/cm^2]) for Mp < 150ME; log(Rp/RE) = 0.67 - 0.036 log(M/ME) + 0.06 log(F/[erg/s/cm^2]) for Mp > 150ME. We also solve these planes in density-mass-flux space: log(ρp/[g/cm^3]) = 0.69 - 0.57 log(M/ME) + 0.02 log(F/[erg/s/cm^2]) for Mp < 150ME; log(ρp/[g/cm^3]) = -1.23 + 1.10 log(M/ME) - 0.18 log(F/[erg/s/cm^2]) for Mp > 150ME.

  20. What Is the Largest Einstein Radius in the Universe?

    SciTech Connect

    Oguri, Masamune; Blandford, Roger D.

    2008-08-05

    The Einstein radius plays a central role in lens studies as it characterizes the strength of gravitational lensing. In particular, the distribution of Einstein radii near the upper cutoff should probe the probability distribution of the largest mass concentrations in the universe. Adopting a triaxial halo model, we compute expected distributions of large Einstein radii. To assess the cosmic variance, we generate a number of Monte-Carlo realizations of all-sky catalogues of massive clusters. We find that the expected largest Einstein radius in the universe is sensitive to parameters characterizing the cosmological model, especially {sigma}{sub s}: for a source redshift of unity, they are 42{sub -7}{sup +9}, 35{sub -6}{sup +8}, and 54{sub -7}{sup +12} arcseconds (errors denote 1{sigma} cosmic variance), assuming best-fit cosmological parameters of the Wilkinson Microwave Anisotropy Probe five-year (WMAP5), three-year (WMAP3) and one-year (WMAP1) data, respectively. These values are broadly consistent with current observations given their incompleteness. The mass of the largest lens cluster can be as small as {approx} 10{sup 15} M{sub {circle_dot}}. For the same source redshift, we expect in all-sky {approx} 35 (WMAP5), {approx} 15 (WMAP3), and {approx} 150 (WMAP1) clusters that have Einstein radii larger than 2000. For a larger source redshift of 7, the largest Einstein radii grow approximately twice as large. While the values of the largest Einstein radii are almost unaffected by the level of the primordial non-Gaussianity currently of interest, the measurement of the abundance of moderately large lens clusters should probe non-Gaussianity competitively with cosmic microwave background experiments, but only if other cosmological parameters are well-measured. These semi-analytic predictions are based on a rather simple representation of clusters, and hence calibrating them with N-body simulations will help to improve the accuracy. We also find that these 'superlens

  1. Three-dimensional mapping and comparative analysis of the distal human corpus cavernosum and the inflatable penile prosthesis.

    PubMed

    Hakky, Tariq S; Ferguson, Daniel; Spiess, Philippe E; Bradley, Paul; Lue, Tom F; Carrion, Rafael E

    2013-07-01

    The intricate anatomy of the corpus cavernosum in both the flaccid and tumescent state has not been fully elucidated. We report our experience using a three-dimensional (3D) scanner to reconstruct cadaveric casts and compare them with 3D images of two prototypes of penile prosthesis. Two different models of the Titan Coloplast inflatable penile prosthesis were analyzed using a 3D scanner. The first was the standard model and the second was a newer model with a rounder silicone tip. Two cadaveric phalluses were harvested using Smooth-Cast 300Q polyurethane molding. The molds were excised and scanned along side the penile prosthesis. 3D scans were completed and analyzed using Leios Mesh software, and GOM Inspect software. The 3D scans demonstrated the mean human corporal radii 2 mm from the distal tip to be 36.51 mm (36.01-37.0 mm), which is an obtuse angle. The standard Titan penile prosthesis spherical radius at the same level was 202.52 mm, while the new silicone tip prosthesis had a radius of 139.33 mm. 3D mapping further demonstrated the trajectory of the cavernosa appeared curvilinear and the distal ends appeared blunt. The use of cadaveric cavernosal molds in combination with the 3D scanner allowed us to accurately image the corpus cavernosum for the first time. Our findings suggest that anatomically accurate corporal tips appear to be relatively blunt and that the new Titan silicone tip penile prosthesis more closely resembles the human corporal tip.

  2. Massive radius-dependent flow slippage in carbon nanotubes.

    PubMed

    Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Siria, Alessandro; Bocquet, Lydéric

    2016-01-01

    Measurements and simulations have found that water moves through carbon nanotubes at exceptionally high rates owing to nearly frictionless interfaces. These observations have stimulated interest in nanotube-based membranes for applications including desalination, nano-filtration and energy harvesting, yet the exact mechanisms of water transport inside the nanotubes and at the water-carbon interface continue to be debated because existing theories do not provide a satisfactory explanation for the limited number of experimental results available so far. This lack of experimental results arises because, even though controlled and systematic studies have explored transport through individual nanotubes, none has met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube. Here we show that the pressure-driven flow rate through individual nanotubes can be determined with unprecedented sensitivity and without dyes from the hydrodynamics of water jets as they emerge from single nanotubes into a surrounding fluid. Our measurements reveal unexpectedly large and radius-dependent surface slippage in carbon nanotubes, and no slippage in boron nitride nanotubes that are crystallographically similar to carbon nanotubes, but electronically different. This pronounced contrast between the two systems must originate from subtle differences in the atomic-scale details of their solid-liquid interfaces, illustrating that nanofluidics is the frontier at which the continuum picture of fluid mechanics meets the atomic nature of matter. PMID:27604947

  3. Mass-Radius Relation for Rocky Planets Based on PREM

    NASA Astrophysics Data System (ADS)

    Zeng, Li; Sasselov, Dimitar D.; Jacobsen, Stein B.

    2016-03-01

    Several small dense exoplanets are now known, inviting comparisons to Earth and Venus. Such comparisons require translating their masses and sizes to composition models of evolved multi-layer interior planets. Such theoretical models rely on our understanding of the Earth’s interior, as well as independently derived equations of state, but so far have not involved direct extrapolations from Earth’s seismic model: the Preliminary Reference Earth Model (PREM). To facilitate more detailed compositional comparisons between small exoplanets and the Earth, we derive here a semi-empirical mass-radius relation for two-layer rocky planets based on PREM, \\frac{R}{{R}\\oplus }=(1.07-0.21\\cdot {CMF})\\cdot {≤ft(\\frac{M}{{M}\\oplus }\\right)}1/3.7, where CMF stands for core mass fraction. It is applicable to 1 ˜ 8 M⊕ and a CMF of 0.0 ˜ 0.4. Applying this formula to Earth and Venus and several known small exoplanets with radii and masses measured to better than ˜30% precision gives a CMF fit of 0.26 ± 0.07.

  4. Optimum Cavity Radius Within a Bottle-Shaped Thermoacoustic Engine

    NASA Astrophysics Data System (ADS)

    Bridge, Justin; Andersen, Bonnie

    2009-10-01

    Heat energy can be used to generate acoustic energy due to thermoacoustic interactions. These engines can be used to create sound waves without any moving parts, like pistons, and could be used in space to convert solar energy into electricity. This research focused on the optimization of the geometry of bottle-shaped resonators used for thermoacoustic prime movers. These resonators have the advantage of non-harmonic overtones compared with half-wave resonators. The resonators for this research were constructed of concentric cylinders consisting of a neck piece and a cavity. The dimensions were approximately 5 cm with an ID of 2 cm for the neck and 10 cm long with IDs varying from about 2 cm to 12 cm for the cavity, producing operating frequencies ranging from approximately 1.2 to 1.5 kHz, following a theoretical model. Twelve different cavity radii were tested. The optimal cavity radius of 2.06 cm had an onset time that was 27 s faster and an onset temperature difference that was lower by 12 C than the smallest cavity (a half-wave resonator). Future research will explore the quality factor and optimum stack to surface area ratio of the engines.

  5. Thrombocytopenia-absent radius syndrome: a clinical genetic study

    PubMed Central

    Greenhalgh, K; Howell, R; Bottani, A; Ancliff, P; Brunner, H; Verschuuren-Bemel..., C; Vernon, E; Brown, K; Newbury-Ecob, R

    2002-01-01

    The thrombocytopenia-absent radius (TAR) syndrome is a congenital malformation syndrome characterised by bilateral absence of the radii and a thrombocytopenia. The lower limbs, gastrointestinal, cardiovascular, and other systems may also be involved. Shaw and Oliver in 1959 were the first to describe this condition, but it was Hall et al in 1969 who reported the first major series of patients. Since then most reports have been based on single or small numbers of cases. We report the results of a clinical study looking at the phenotype of 34 patients with TAR syndrome. All cases had a documented thrombocytopenia and bilateral radial aplasia, 47% had lower limb anomalies, 47% cow's milk intolerance, 23% renal anomalies, and 15% cardiac anomalies. Congenital anomalies not previously described in association with TAR syndrome included facial capillary haemangiomata, intracranial vascular malformation, sensorineural hearing loss, and scoliosis. Karyotype analysis, chromosome breakage studies including premature centromeric separation and fluorescence in situ hybridisation studies looking for a deletion of chromosome 22q11 were undertaken. Two abnormal karyotypes were identified. PMID:12471199

  6. Measurement of small radius gradient magnets using ion beams

    SciTech Connect

    Charles W. Schmidt et al.

    2001-07-16

    Several small and precise 90{degree}, 20-inch-radius bending and focusing magnet systems will be needed for the transport line of the Fermilab Electron Cooling Project to transport 4.36 MeV electrons. Originally, it was anticipated that these magnets would have a gradient index of {minus}1/2. To measure these magnets and complete achromatic bend modules, a well defined beam transport system was developed to determine the transfer matrix knowing the position and angle of several input and output beam rays passing through the magnet. The beam for this was a 12.5 keV proton beam that has the same magnetic rigidity as the electron beam in the final setup. The magnetic field is approximately 300 Gauss. For this purpose a high-brightness proton source was used and the beam collimated to give a low emittance ({approximately}10{sup {minus}8} m rad) pencil beam of {approximately}1 mm diameter with a current of {approximately}100 nA. Details of the system and results of measuring a magnet will be presented.

  7. Placing molecules with Bohr radius resolution using DNA origami.

    PubMed

    Funke, Jonas J; Dietz, Hendrik

    2016-01-01

    Molecular self-assembly with nucleic acids can be used to fabricate discrete objects with defined sizes and arbitrary shapes. It relies on building blocks that are commensurate to those of biological macromolecular machines and should therefore be capable of delivering the atomic-scale placement accuracy known today only from natural and designed proteins. However, research in the field has predominantly focused on producing increasingly large and complex, but more coarsely defined, objects and placing them in an orderly manner on solid substrates. So far, few objects afford a design accuracy better than 5 nm, and the subnanometre scale has been reached only within the unit cells of designed DNA crystals. Here, we report a molecular positioning device made from a hinged DNA origami object in which the angle between the two structural units can be controlled with adjuster helices. To test the positioning capabilities of the device, we used photophysical and crosslinking assays that report the coordinate of interest directly with atomic resolution. Using this combination of placement and analysis, we rationally adjusted the average distance between fluorescent molecules and reactive groups from 1.5 to 9 nm in 123 discrete displacement steps. The smallest displacement step possible was 0.04 nm, which is slightly less than the Bohr radius. The fluctuation amplitudes in the distance coordinate were also small (±0.5 nm), and within a factor of two to three of the amplitudes found in protein structures. PMID:26479026

  8. Massive radius-dependent flow slippage in carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Siria, Alessandro; Bocquet, Lydéric

    2016-09-01

    Measurements and simulations have found that water moves through carbon nanotubes at exceptionally high rates owing to nearly frictionless interfaces. These observations have stimulated interest in nanotube-based membranes for applications including desalination, nano-filtration and energy harvesting, yet the exact mechanisms of water transport inside the nanotubes and at the water–carbon interface continue to be debated because existing theories do not provide a satisfactory explanation for the limited number of experimental results available so far. This lack of experimental results arises because, even though controlled and systematic studies have explored transport through individual nanotubes, none has met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube. Here we show that the pressure-driven flow rate through individual nanotubes can be determined with unprecedented sensitivity and without dyes from the hydrodynamics of water jets as they emerge from single nanotubes into a surrounding fluid. Our measurements reveal unexpectedly large and radius-dependent surface slippage in carbon nanotubes, and no slippage in boron nitride nanotubes that are crystallographically similar to carbon nanotubes, but electronically different. This pronounced contrast between the two systems must originate from subtle differences in the atomic-scale details of their solid–liquid interfaces, illustrating that nanofluidics is the frontier at which the continuum picture of fluid mechanics meets the atomic nature of matter.

  9. Placing molecules with Bohr radius resolution using DNA origami

    NASA Astrophysics Data System (ADS)

    Funke, Jonas J.; Dietz, Hendrik

    2016-01-01

    Molecular self-assembly with nucleic acids can be used to fabricate discrete objects with defined sizes and arbitrary shapes. It relies on building blocks that are commensurate to those of biological macromolecular machines and should therefore be capable of delivering the atomic-scale placement accuracy known today only from natural and designed proteins. However, research in the field has predominantly focused on producing increasingly large and complex, but more coarsely defined, objects and placing them in an orderly manner on solid substrates. So far, few objects afford a design accuracy better than 5 nm, and the subnanometre scale has been reached only within the unit cells of designed DNA crystals. Here, we report a molecular positioning device made from a hinged DNA origami object in which the angle between the two structural units can be controlled with adjuster helices. To test the positioning capabilities of the device, we used photophysical and crosslinking assays that report the coordinate of interest directly with atomic resolution. Using this combination of placement and analysis, we rationally adjusted the average distance between fluorescent molecules and reactive groups from 1.5 to 9 nm in 123 discrete displacement steps. The smallest displacement step possible was 0.04 nm, which is slightly less than the Bohr radius. The fluctuation amplitudes in the distance coordinate were also small (±0.5 nm), and within a factor of two to three of the amplitudes found in protein structures.

  10. MASS-RADIUS RELATIONSHIPS FOR VERY LOW MASS GASEOUS PLANETS

    SciTech Connect

    Batygin, Konstantin; Stevenson, David J.

    2013-05-20

    Recently, the Kepler spacecraft has detected a sizable aggregate of objects, characterized by giant-planet-like radii and modest levels of stellar irradiation. With the exception of a handful of objects, the physical nature, and specifically the average densities, of these bodies remain unknown. Here, we propose that the detected giant planet radii may partially belong to planets somewhat less massive than Uranus and Neptune. Accordingly, in this work, we seek to identify a physically sound upper limit to planetary radii at low masses and moderate equilibrium temperatures. As a guiding example, we analyze the interior structure of the Neptune-mass planet Kepler-30d and show that it is acutely deficient in heavy elements, especially compared with its solar system counterparts. Subsequently, we perform numerical simulations of planetary thermal evolution and in agreement with previous studies, show that generally, 10-20 M{sub Circled-Plus }, multi-billion year old planets, composed of high density cores and extended H/He envelopes can have radii that firmly reside in the giant planet range. We subject our results to stability criteria based on extreme ultraviolet radiation, as well as Roche-lobe overflow driven mass-loss and construct mass-radius relationships for the considered objects. We conclude by discussing observational avenues that may be used to confirm or repudiate the existence of putative low mass, gas-dominated planets.

  11. Determination of Optimal Blank Shape by Radius Vector Method

    NASA Astrophysics Data System (ADS)

    Shim, Hyun Bo; Park, Jong Kyu; Kim, Yang Soo

    2004-06-01

    A new method of optimal blank shape design for stampings of arbitrary shapes has been proposed. Similar to the sensitivity method, a past work of the present author, the basic nature of this method is iterative modification of an undeformed blank shape by adjusting the nodal positions at the boundary of the blank, until the final shape satisfies a target shape. The main difference from the sensitivity method is that both shape error measure and blank shape modification is done along the normal to a boundary direction in the current method instead of nodal moving direction as in the sensitivity method. Even though the sensitivity method has been proven to be excellent through experiment, huge computational effort is still a problem since the method requires a couple of deformation process analyses per each design stage. Differently from the sensitivity method, the present radius vector method requires only a single deformation analysis per each design step and it can handle an extraordinary motion due to a rigid-body rotation during forming. Drawings of L-shaped cup and wheel housing have been chosen as the examples to verify the present method. In every cases the optimal blank shapes have been obtained after a few times of modification. Through the investigation, the present method, which incorporates normal to boundary is found to be an excellent, or better than the sensitivity method, which incorporates moving direction, for the optimal blank design.

  12. Carpals and epiphyses of radius and ulna as age indicators.

    PubMed

    Cameriere, Roberto; Ferrante, Luigi; Mirtella, Dora; Cingolani, Mariano

    2006-05-01

    Estimation of skeletal age using radiographic images is widely used for assessing biological growth in clinical and auxological studies. The most frequent areas used for age estimation in children and adolescents are tooth and wrist/hand, both giving good results with only a low level of radiation. In particular, ossification of the carpals shows good agreement with chronological age. This study of a sample of 150 Italian children and adolescents aged between 5 and 17 years focused on analyzing the possible applications of the proportion of carpal area (Ca) mineralization as a criterion of age estimation. The ratio between the total area of carpal bones and epiphyses of the ulna and radius (Bo) and Ca was calculated. This ratio (Bo/Ca) was used for linear regression analysis. The regression model, describing age as a linear function of the ratio Bo/Ca, yielded the following equation: Age=-3.253+0.719 g+20.610 Bo/Ca, and explained 83% of the total variance (R (2)=0.83). The median of the absolute values of residuals (observed age minus predicted age) was 0.08 years, with a quartile deviation of 1.59 years, and a standard error of estimate of 1.19 years.

  13. Mass-radius relation of strongly magnetized white dwarfs

    NASA Astrophysics Data System (ADS)

    Bera, Prasanta; Bhattacharya, Dipankar

    2016-07-01

    We study the strongly magnetized white dwarf configurations in a self-consistent manner as a progenitor of the over-luminous type-Ia supernovae. We compute static equilibria of white dwarf stars containing a strong magnetic field and present the modification of white dwarf mass-radius relation caused by the magnetic field. From a static equilibrium study, we find that a maximum white dwarf mass of about 1.9 M_{⊙} may be supported if the interior poloidal field is as strong as approximately 10^{10} T. On the other hand, if the field is purely toroidal the maximum mass can be more than 5 M_⊙. All these modifications are mainly from the presence of Lorenz force. The effects of i) modification of equation of state due to Landau quantization ii) electrostatic interaction due to ions, ii) general relativistic calculation on the stellar structure and, iii) field geometry are also considered. These strongly magnetised configurations are sensitive to magnetic instabilities where the perturbations grow at the corresponding Alfven time scales.

  14. Massive radius-dependent flow slippage in carbon nanotubes.

    PubMed

    Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Siria, Alessandro; Bocquet, Lydéric

    2016-09-07

    Measurements and simulations have found that water moves through carbon nanotubes at exceptionally high rates owing to nearly frictionless interfaces. These observations have stimulated interest in nanotube-based membranes for applications including desalination, nano-filtration and energy harvesting, yet the exact mechanisms of water transport inside the nanotubes and at the water-carbon interface continue to be debated because existing theories do not provide a satisfactory explanation for the limited number of experimental results available so far. This lack of experimental results arises because, even though controlled and systematic studies have explored transport through individual nanotubes, none has met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube. Here we show that the pressure-driven flow rate through individual nanotubes can be determined with unprecedented sensitivity and without dyes from the hydrodynamics of water jets as they emerge from single nanotubes into a surrounding fluid. Our measurements reveal unexpectedly large and radius-dependent surface slippage in carbon nanotubes, and no slippage in boron nitride nanotubes that are crystallographically similar to carbon nanotubes, but electronically different. This pronounced contrast between the two systems must originate from subtle differences in the atomic-scale details of their solid-liquid interfaces, illustrating that nanofluidics is the frontier at which the continuum picture of fluid mechanics meets the atomic nature of matter.

  15. Placing molecules with Bohr radius resolution using DNA origami.

    PubMed

    Funke, Jonas J; Dietz, Hendrik

    2016-01-01

    Molecular self-assembly with nucleic acids can be used to fabricate discrete objects with defined sizes and arbitrary shapes. It relies on building blocks that are commensurate to those of biological macromolecular machines and should therefore be capable of delivering the atomic-scale placement accuracy known today only from natural and designed proteins. However, research in the field has predominantly focused on producing increasingly large and complex, but more coarsely defined, objects and placing them in an orderly manner on solid substrates. So far, few objects afford a design accuracy better than 5 nm, and the subnanometre scale has been reached only within the unit cells of designed DNA crystals. Here, we report a molecular positioning device made from a hinged DNA origami object in which the angle between the two structural units can be controlled with adjuster helices. To test the positioning capabilities of the device, we used photophysical and crosslinking assays that report the coordinate of interest directly with atomic resolution. Using this combination of placement and analysis, we rationally adjusted the average distance between fluorescent molecules and reactive groups from 1.5 to 9 nm in 123 discrete displacement steps. The smallest displacement step possible was 0.04 nm, which is slightly less than the Bohr radius. The fluctuation amplitudes in the distance coordinate were also small (±0.5 nm), and within a factor of two to three of the amplitudes found in protein structures.

  16. The mass-radius relationship of massive compact stars

    SciTech Connect

    Chowdhury, Partha Roy

    2015-02-24

    The properties of pure hadronic and hybrid compact stars are reviewed using nuclear equation of state (EoS) for β-equilibrated neutron star (NS) matter obtained using a density-dependent M3Y (DDM3Y) effective nucleon-nucleon interaction. Depending on the model, the energy density of quark matter can be lower than that of this nuclear EoS at higher densities, implying the possibility of transition to quark matter inside the core and the transition density depends on the particular quark matter model used. The recent observations of the binary millisecond pulsar J1614–2230 by P.B. Demorest et al. [1] and PSR J0348+0432 by J. Antoniadis et al. [2] suggest that the masses lie within 1.97 ± 0.04 M{sub ⊙} and 2.01 ± 0.04 M{sub ⊙}, respectively, where M{sub ⊙} is the solar mass. In conformity with recent observations, a pure nucleonic EoS determines that the maximum mass of NS rotating with frequency ν∼ 667 Hz below r-mode instability is ∼ 1.95 M{sub ⊙} with radius ∼ 10 km. Compact stars with quark cores rotating with same frequency have the maximum mass of ∼ 1.72 M{sub ⊙} turns out to be lower than the observed masses.

  17. Massive radius-dependent flow slippage in carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Siria, Alessandro; Bocquet, Lydéric

    2016-09-01

    Measurements and simulations have found that water moves through carbon nanotubes at exceptionally high rates owing to nearly frictionless interfaces. These observations have stimulated interest in nanotube-based membranes for applications including desalination, nano-filtration and energy harvesting, yet the exact mechanisms of water transport inside the nanotubes and at the water-carbon interface continue to be debated because existing theories do not provide a satisfactory explanation for the limited number of experimental results available so far. This lack of experimental results arises because, even though controlled and systematic studies have explored transport through individual nanotubes, none has met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube. Here we show that the pressure-driven flow rate through individual nanotubes can be determined with unprecedented sensitivity and without dyes from the hydrodynamics of water jets as they emerge from single nanotubes into a surrounding fluid. Our measurements reveal unexpectedly large and radius-dependent surface slippage in carbon nanotubes, and no slippage in boron nitride nanotubes that are crystallographically similar to carbon nanotubes, but electronically different. This pronounced contrast between the two systems must originate from subtle differences in the atomic-scale details of their solid-liquid interfaces, illustrating that nanofluidics is the frontier at which the continuum picture of fluid mechanics meets the atomic nature of matter.

  18. Treatment of distal humerus fractures in adults: a historical perspective.

    PubMed

    Kozánek, Michal; Bartoníček, Jan; Chase, Samantha M; Jupiter, Jesse B

    2014-12-01

    Nonsurgical treatment was the mainstay of management of distal humerus fractures for centuries and nonunions and malunions were common. The 19th century featured the recognition of distinct injury patterns. With advances in radiology, anesthesia, antisepsis, and hardware technology, surgical treatment is now generally preferred, yet loss of elbow joint mobility can still be a vexing problem.

  19. Proximal versus Distal Validity Coefficients for Teacher Observational Instruments

    ERIC Educational Resources Information Center

    Marzano, Robert J.

    2014-01-01

    This study examined the use of measures of student learning computed using end-of-year assessments (distal measures) versus measures of student learning associated with a single lesson (proximal measures) as criterion scores for the validity of observations of teachers' pedagogical skills. The validity coefficients computed using distal…

  20. Sural Versus Perforator Flaps for Distal Medial Leg Wounds.

    PubMed

    Schannen, Andrew P; Truchan, Lisa; Goshima, Kaoru; Bentley, Roger; DeSilva, Gregory L

    2015-12-01

    Soft tissue coverage of distal medial ankle wounds is a challenging problem in orthopedic surgery because of the limited local tissues and prominent instrumentation. Traditionally, these wounds required free tissue transfer to achieve suitable coverage and subsequent bony union. To better respect the reconstructive ladder and to avoid the inherent difficulty of free flap coverage, rotational flaps have been used to cover these wounds. Both sural fasciocutaneous flaps and rotational fasciocutaneous perforator (propeller) flaps have been described for distal medial soft tissue coverage. The authors performed a retrospective chart review of patients who underwent distal medial leg coverage with the use of either sural flaps or rotational fasciocutaneous perforator flaps. The authors identified 14 patients by Current Procedural Terminology code who met the study criteria. The average age and degree of medical comorbidities were comparable in the 2 groups. The authors reviewed their medical records to evaluate fracture healing, flap size, complications, and return to normal shoe wear. All 7 sural flaps healed without incident, with underlying fracture healing. Of the 7 perforator flaps, 6 healed without incident, with underlying fracture healing. One perforator-based flap was complicated by superficial tip necrosis and went on to heal with local wound care. All patients returned to normal shoe wear. Both sural artery rotational flaps and posterior tibial artery-based rotational flaps are viable options for coverage of the distal medial leg. Coverage can be achieved reliably without microsurgery, anticoagulation, or monitoring in the intensive care unit. PMID:26652325

  1. Distally Based Iliotibial Band Flap: Anatomic Study with Surgical Considerations.

    PubMed

    Wong, Victor W; Higgins, James P

    2016-09-01

    Background Reconstruction of high-risk fascia, tendon, or ligament defects may benefit from vascularized tissue. The iliotibial band (ITB), a thick fibrous tract of connective tissue, serves as a potential donor site for free tissue transfer but its blood supply has not been thoroughly investigated. The aim of this anatomical study was to investigate the vascular supply to the distal ITB and its role as a free fascial flap. Methods We dissected 16 fresh-frozen cadaveric legs and injected latex into the superolateral geniculate artery (SLGA). A distal ITB fascial flap was designed and measurements were taken for flap dimensions, pedicle length and size, and SLGA perfusion territory. Results The SLGA perfused 11.5 ± 2.3 cm of distal ITB (proximal to the lateral femoral epicondyle) and provided 6.4 ± 0.7cm of pedicle length to the ITB flap. Conclusions Chimeric options to include bone (from the lateral femoral condyle), cartilage (from the lateral femoral trochlea), muscle (from vastus lateralis or biceps femoris), and skin are possible. Surgical harvest techniques are proposed, including preservation of ITB insertions to minimize lateral knee instability. Clinical validation is needed to determine the role of the distal ITB free fascial flap in reconstructive microsurgery.

  2. Genetics Home Reference: CAV3-related distal myopathy

    MedlinePlus

    ... gene causes a peculiar form of distal myopathy. Neurology. 2002 Jan 22;58(2):323-5. Erratum in: Neurology 2002 Mar 12;58(5):839. Itoyoma Y [ ... 3 cause four distinct autosomal dominant muscle diseases. Neurology. 2004 Feb 24;62(4):538-43. Review. ...

  3. Autosomal dominant distal myopathy: Linkage to chromosome 14

    SciTech Connect

    Laing, N.G.; Laing, B.A.; Wilton, S.D.; Dorosz, S.; Mastaglia, F.L.; Kakulas, B.A.; Robbins, P.; Meredith, C.; Honeyman, K.; Kozman, H.

    1995-02-01

    We have studied a family segregating a form of autosomal dominant distal myopathy (MIM 160500) and containing nine living affected individuals. The myopathy in this family is closest in clinical phenotype to that first described by Gowers in 1902. A search for linkage was conducted using microsatellite, VNTR, and RFLP markers. In total, 92 markers on all 22 autosomes were run. Positive linkage was obtained with 14 of 15 markers tested on chromosome 14, with little indication of linkage elsewhere in the genome. Maximum two-point LOD scores of 2.60 at recombination fraction .00 were obtained for the markers MYH7 and D14S64 - the family structure precludes a two-point LOD score {ge} 3. Recombinations with D14S72 and D14S49 indicate that this distal myopathy locus, MPD1, should lie between these markers. A multipoint analysis assuming 100% penetrance and using the markers D14S72, D14S50, MYH7, D14S64, D14S54, and D14S49 gave a LOD score of exactly 3 at MYH7. Analysis at a penetrance of 80% gave a LOD score of 2.8 at this marker. This probable localization of a gene for distal myopathy, MPD1, on chromosome 14 should allow other investigators studying distal myopathy families to test this region for linkage in other types of the disease, to confirm linkage or to demonstrate the likely genetic heterogeneity. 24 refs., 3 figs., 1 tab.

  4. Management of distal humeral fractures in the elderly.

    PubMed

    Strauss, Eric J; Alaia, Michael; Egol, Kenneth A

    2007-09-01

    Although relatively uncommon, fractures of the distal humerus in the elderly patient population are significant injuries of which optimal management is a subject of debate in orthopaedic literature. The combination of complex anatomy, poor bone quality and extensive comminution often seen with these fractures makes successful treatment difficult. Currently, most surgeons support surgical fixation of distal humeral fractures with the belief that restoration of the patient's native elbow joint provides the best opportunity for a good functional outcome. Others have proposed the use of total elbow arthroplasty as a primary treatment method for geriatric distal humeral fractures based on the difficulties associated with ORIF and the relatively low demands of this patient population. To date, there have been no prospective randomised trials comparing these two treatment alternatives, and a comparison of available outcome data shows good functional outcome for both forms of fracture management. With the aging of the population and an associated increase in the incidence of distal humeral fractures, the debate over the optimal treatment regime will undoubtedly continue. PMID:17723787

  5. Prediction of distal residue participation in enzyme catalysis.

    PubMed

    Brodkin, Heather R; DeLateur, Nicholas A; Somarowthu, Srinivas; Mills, Caitlyn L; Novak, Walter R; Beuning, Penny J; Ringe, Dagmar; Ondrechen, Mary Jo

    2015-05-01

    A scoring method for the prediction of catalytically important residues in enzyme structures is presented and used to examine the participation of distal residues in enzyme catalysis. Scores are based on the Partial Order Optimum Likelihood (POOL) machine learning method, using computed electrostatic properties, surface geometric features, and information obtained from the phylogenetic tree as input features. Predictions of distal residue participation in catalysis are compared with experimental kinetics data from the literature on variants of the featured enzymes; some additional kinetics measurements are reported for variants of Pseudomonas putida nitrile hydratase (ppNH) and for Escherichia coli alkaline phosphatase (AP). The multilayer active sites of P. putida nitrile hydratase and of human phosphoglucose isomerase are predicted by the POOL log ZP scores, as is the single-layer active site of P. putida ketosteroid isomerase. The log ZP score cutoff utilized here results in over-prediction of distal residue involvement in E. coli alkaline phosphatase. While fewer experimental data points are available for P. putida mandelate racemase and for human carbonic anhydrase II, the POOL log ZP scores properly predict the previously reported participation of distal residues.

  6. Non-reducible palmar dislocation of the distal radioulnar joint

    PubMed Central

    Zannou, Rupestre S.; Rezzouk, Joel; Ruijs, Aleid C.J.

    2015-01-01

    Abstract A rare case of an isolated traumatic palmar dislocation of the distal radioulnar joint is presented. Clinically, there is a loss of pronation and supination. The dislocation was treated using an open reduction, reinsertion of the capsule-ligamentous complex and temporary stabilization using K-wires. PMID:26158121

  7. Exposures of the wrist and distal radioulnar joint.

    PubMed

    Bickel, Kyle D

    2014-11-01

    This article reviews the superficial, skeletal, and ligamentous anatomy of the wrist. Standard and alternative exposures of the wrist joint and the distal radioulnar joint are discussed, emphasizing the importance of avoiding nerve injury. Standard exposure of the wrist joint is used in the treatment of carpal ligament injuries, fractures, and dislocations. Case presentations illustrate these techniques.

  8. Distally Based Iliotibial Band Flap: Anatomic Study with Surgical Considerations.

    PubMed

    Wong, Victor W; Higgins, James P

    2016-09-01

    Background Reconstruction of high-risk fascia, tendon, or ligament defects may benefit from vascularized tissue. The iliotibial band (ITB), a thick fibrous tract of connective tissue, serves as a potential donor site for free tissue transfer but its blood supply has not been thoroughly investigated. The aim of this anatomical study was to investigate the vascular supply to the distal ITB and its role as a free fascial flap. Methods We dissected 16 fresh-frozen cadaveric legs and injected latex into the superolateral geniculate artery (SLGA). A distal ITB fascial flap was designed and measurements were taken for flap dimensions, pedicle length and size, and SLGA perfusion territory. Results The SLGA perfused 11.5 ± 2.3 cm of distal ITB (proximal to the lateral femoral epicondyle) and provided 6.4 ± 0.7cm of pedicle length to the ITB flap. Conclusions Chimeric options to include bone (from the lateral femoral condyle), cartilage (from the lateral femoral trochlea), muscle (from vastus lateralis or biceps femoris), and skin are possible. Surgical harvest techniques are proposed, including preservation of ITB insertions to minimize lateral knee instability. Clinical validation is needed to determine the role of the distal ITB free fascial flap in reconstructive microsurgery. PMID:27135145

  9. Haptic Distal Spatial Perception Mediated by Strings: Haptic "Looming"

    ERIC Educational Resources Information Center

    Cabe, Patrick A.

    2011-01-01

    Five experiments tested a haptic analog of optical looming, demonstrating string-mediated haptic distal spatial perception. Horizontally collinear hooks supported a weighted string held taut by a blindfolded participant's finger midway between the hooks. At the finger, the angle between string segments increased as the finger approached…

  10. The distal shoe space maintainer chairside fabrication and clinical performance.

    PubMed

    Brill, Warren A

    2002-01-01

    The chairside-fabricated distal shoe appliance, with a stainless steel crown as the retainer, is an efficacious and cost-effective appliance for guiding the unerupted permanent first molar into position after premature loss or extraction of the second primary molar. The fabrication technique is illustrated in this case report and data is presented on the success rate of the appliance.

  11. [Distalization of the upper second molar: clinical case].

    PubMed

    Castaldo, A; Blasi, S; Vettese, P

    1991-01-01

    The Authors showed a clinical case in which has been put on a distalizing system together with a palatal bar between the first upper molars, a sectional placed between the first and the second molar and a 100 g precalibrated Sentalloy coil. PMID:1784297

  12. Distal Prosodic Context Affects Word Segmentation and Lexical Processing

    ERIC Educational Resources Information Center

    Dilley, Laura C.; McAuley, J. Devin

    2008-01-01

    Three experiments investigated the role of distal (i.e., nonlocal) prosody in word segmentation and lexical processing. In Experiment 1, prosodic characteristics of the initial five syllables of eight-syllable sequences were manipulated; the final portions of these sequences were lexically ambiguous (e.g., "note bookworm", "notebook worm"). Distal…

  13. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe.

    PubMed

    Nakashima, Kenichi; Stoller, Roger E; Xu, Haixuan

    2015-08-26

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in irradiated materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1.0a0 to 3.3a0 have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomic level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a0 by taking the average of the recombination distances from 80 simulation cases. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster. PMID:26241190

  14. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe

    NASA Astrophysics Data System (ADS)

    Nakashima, Kenichi; Stoller, Roger E.; Xu, Haixuan

    2015-08-01

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in irradiated materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1.0a0 to 3.3a0 have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomic level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a0 by taking the average of the recombination distances from 80 simulation cases. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster.

  15. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe

    DOE PAGES

    Nakashima, Kenichi; Stoller, Roger E.; Xu, Haixuan

    2015-01-01

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in neutron irradiated nuclear materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1:0a₀ to 3:3a₀ have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomicmore » level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a₀ by taking the average of the recombination distances from 80 simulation cases. This value agrees well with the experimental estimate. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster.« less

  16. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe

    SciTech Connect

    Nakashima, Kenichi; Stoller, Roger E.; Xu, Haixuan

    2015-01-01

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in neutron irradiated nuclear materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1:0a₀ to 3:3a₀ have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomic level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a₀ by taking the average of the recombination distances from 80 simulation cases. This value agrees well with the experimental estimate. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster.

  17. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe.

    PubMed

    Nakashima, Kenichi; Stoller, Roger E; Xu, Haixuan

    2015-08-26

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in irradiated materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1.0a0 to 3.3a0 have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomic level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a0 by taking the average of the recombination distances from 80 simulation cases. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster.

  18. Effect of orifice inner lip radius on synthetic jet efficiency

    NASA Astrophysics Data System (ADS)

    Nani, David J.; Smith, Barton L.

    2012-11-01

    A synthetic jet is formed by periodic oscillation of a fluid through an orifice. The oscillatory motion is driven by a diaphragm or other driver. Previous studies have demonstrated that synthetic jet formation and time-averaged cavity pressure are a function of the orifice shape. Traditionally, the performance of the jet is evaluated with varying configurations of fixed driver input voltage or fixed driver displacement. Neither of these measures accurately reflect the efficiency of the actuator. Defining efficiency as "desired output divided by required input," these traditional measures may not account for increase in required driving current or force. A sharp inside edge of a thin synthetic jet orifice can result in separated flow and increased momentum flux (due to the decreased flow area) for a fixed driver displacement. This can lead one to believe that efficiency has been improved, when, in reality, much more power was required for the driver. Acoustic power, which is the time-average of volume flow rate through the orifice multiplied by the driving pressure, accurately accounts for the power required to drive the actuator. For any synthetic jet actuator, the power to the driver is the power to the fluid (acoustic power) divided by the driver efficiency. If we assume that the driver efficiency is not a strong function of the load, any change to the acoustic power will result in the same proportional change in the driver input power. This study investigates the efficiency of a round (axisymmetric) synthetic jet actuator as a function of the radius of curvature of the interior edge of the orifice. Simultaneous particle image velocimetry measurements at the jet exit and cavity pressure measurements are used to measure the acoustic power required to generate the jet. The resultant momentum flux of the jet is used as a measure of output of the jet. Results are obtained for a range of displacement amplitudes (or stroke lengths) and radii of curvature, while

  19. Rights and wrongs of the temporal solar radius variability

    NASA Astrophysics Data System (ADS)

    Rozelot, J. P.; Damiani, C.

    2012-10-01

    From time immemorial men have strived to measure the size of celestial bodies. Among them, the diameter of the Sun was a source of curiosity and study. Tackled by Greek astronomers from a geometric point of view, an estimate, although incorrect, has been first determined, not truly called into question for several centuries. One must wait up to the XVIIth century to get the first precise determinations made by the French school of astronomy. Gradually, as the techniques were more and more sophisticated, many other solar diameter measurements were carried out, notably in England, Germany, Italy and US. However, even with instruments at the cutting edge of progress, no absolute value of the solar diameter has been provided yet, even if the community has adopted a canonical radius of 959''&dotbelow;63, given in all ephemeris since the end of the XIXth century. One of the major difficulties is to define a correct solar diameter. Another issue is the possible temporal variability of the size of the Sun, as first advocated at the end of the XIXth century by the Italian school. Today, this question is just on the way to being solved in spite of considerable efforts developed on ground-based facilities or on board space experiments. We will here give a review of some of the most remarkable techniques used in the past, emphasising how incorrect measurements have driven new ideas, leading to develop new statements for the underlying physics. On such new grounds, it can be speculated that the roundness of the Sun is not perfect, but developing a thin "cantaloupe skin" in periods of higher activity, with departures from sphericity being inevitably bounded by a few kilometers (around 80 km or 10 to 15 mas).

  20. VARIATION OF INNER RADIUS OF DUST TORUS IN NGC4151

    SciTech Connect

    Koshida, Shintaro; Sakata, Yu; Sugawara, Shota; Yoshii, Yuzuru; Minezaki, Takeo; Tomita, Hiroyuki; Kobayashi, Yukiyasu; Suganuma, Masahiro; Enya, Keigo; Aoki, Tsutomu; Peterson, Bruce A.

    2009-08-01

    Long-term optical and near-infrared monitoring observations for a type 1 active galactic nucleus (AGN) NGC 4151 were carried out for six years from 2001 to 2006 by using the MAGNUM telescope, and delayed response of flux variations in the K(2.2 {mu}m) band to those in the V(0.55 {mu}m) band was clearly detected. Based on cross-correlation analysis, we precisely measured a lag time {delta}t for eight separate periods and we found that {delta}t is not constant, changing between 30 and 70 d during the monitoring period. Since {delta}t is the light travel time from the central energy source out to the surrounding dust torus, this is the first convincing evidence that the inner radius of the dust torus did change in an individual AGN. In order to relate such a change of {delta}t with a change of AGN luminosity L, we present a method of taking an average of the observed V-band fluxes that corresponds to the measured value of {delta}t, and we find that the time-changing track of NGC 4151 in the {delta}t versus L diagram during the monitoring period deviates from the relation {delta}t {proportional_to} L {sup 0.5} expected from dust reverberation. This result, combined with the elapsed time from period to period for which {delta}t was measured, indicates that the timescale of dust formation is about one year, which should be taken into account as a new constraint in future studies of dust evolution in AGNs.

  1. A Large Radius Human Centrifuge: The Human Hypergravity Havitat

    NASA Astrophysics Data System (ADS)

    van Loon, J. J. W. A.

    2008-06-01

    Life on Earth has developed at unit gravity, 9.81 m/s2, but how would plants and animals have evolved on a larger planet, i.e. larger than Earth? We are able to address this question simply by studies using centrifuges. In the past decades numerous experiments have been performed on cells, plants and animals grown for longer durations, even multi generations, under hypergravity conditions. Based on these studies we have gained interesting insights in the physiological process of these systems when exposed to artificial gravity. Animals and plants adapt themselves to this new high-g environment. Information of adaptation to hyper-g in mammals is interesting, or maybe even proof vital, for future human space flight programs especially in light of long duration missions to Moon and Mars. We know from long duration animal studies that numerous physiological processes and structures like muscles, bones, neuro-vestibular, or the cardiovascular system are affected. However, humans have never been exposed to a hyper-g environment for long durations. Human studies are mostly in the order of hours at most. Current work on human centrifuges is all focused on short arm systems to apply artificial gravity in long duration space missions. In this paper we want to address the possible usefulness of a large radius human centrifuge on Earth, or even on Moon or Mars, for both basic research and possible applications. In such a centrifuge a group of humans may be exposed to hypergravity for, in principle, an unlimited period of time.

  2. The radius of gyration of an apomyoglobin folding intermediate

    SciTech Connect

    Eliezer, D.; Jennings, P.A.; Wright, P.E.

    1995-10-20

    Apomyoglobin (apoMb) forms a stable compact partially folded state under acidic conditions. This {open_quotes}molten globule{close_quotes} intermediate is slightly expanded relative to the native form of the protein, with a radius of gyration (R{sub g}) of 23 ({plus_minus} 2) {Angstrom} versus 19 ({plus_minus}) {Angstrom}, and shows stable secondary structure in the A,G, and H helices. We demonstrated recently, with the use of stopped-flow circular dichroism and pulse-labeling hydrogen exchange measurements, that the earliest detectable intermediate (formed with 6 ms) in the apoMb kinetic refolding pathway closely resembles the equilibrium molten globule state populated under acid conditions. A key question remained as to how compact this kinetic intermediate is compared to the equilibrium and native states. The cooperative unfolding of the kinetic intermediate and the significant protection from amide proton exchange (as compared to corresponding isolated peptides in solution) led us to propose that the kinetic intermediate is also compact. Such a proposal could best be verified by direct determination of the size of the protein as it folds, but measurements of this nature were not feasible at the time. Newly developed improvements in time-resolved small angle x-ray scattering (SAXS) experiments allow direct measurement of the time-dependent change of R{sub g} of a protein as it folds in the millisecond to second time frame. We initiated studies of the refolding of apoMb using this technique, under conditions similar to those employed in our previous work. SAXS data collected during the first 100 ms after initiation of the refolding reaction are shown. 11 refs., 2 figs.

  3. Contact Radius and the Insulator-Metal Transition in Films Comprised of Touching Semiconductor Nanocrystals.

    PubMed

    Lanigan, Deanna; Thimsen, Elijah

    2016-07-26

    Nanocrystal assemblies are being explored for a number of optoelectronic applications such as transparent conductors, photovoltaic solar cells, and electrochromic windows. Majority carrier transport is important for these applications, yet it remains relatively poorly understood in films comprised of touching nanocrystals. Specifically, the underlying structural parameters expected to determine the transport mechanism have not been fully elucidated. In this report, we demonstrate experimentally that the contact radius, between touching heavily doped ZnO nanocrystals, controls the electron transport mechanism. Spherical nanocrystals are considered, which are connected by a circular area. The radius of this circular area is the contact radius. For nanocrystals that have local majority carrier concentration above the Mott transition, there is a critical contact radius. If the contact radius between nanocrystals is less than the critical value, then the transport mechanism is variable range hopping. If the contact radius is greater than the critical value, the films display behavior consistent with metallic electron transport. PMID:27398597

  4. Minimum required capture radius in a coplanar model of the aerial combat problem

    NASA Technical Reports Server (NTRS)

    Breakwell, J. V.; Merz, A. W.

    1977-01-01

    Coplanar aerial combat is modeled with constant speeds and specified turn rates. The minimum capture radius which will always permit capture, regardless of the initial conditions, is calculated. This 'critical' capture radius is also the maximum range which the evader can guarantee indefinitely if the initial range, for example, is large. A composite barrier is constructed which gives the boundary, at any heading, of relative positions for which the capture radius is less than critical.

  5. A simple approach for fabrication of dual-disk electrodes with a nanometer-radius electrode and a micrometer-radius electrode.

    PubMed

    Gao, Ning; Lin, Xiaohong; Jia, Wenzhi; Zhang, Xiaoli; Jin, Wenrui

    2007-09-30

    We developed a new simple approach to fabricate dual-disk electrodes with a nanometer-radius electrode and a micrometer-radius electrode. First, nanometer-sized electrodes and micrometer-sized electrodes were constructed using 10-mum-radius metal wires, respectively. To fabricate the nanometer-sized electrode, after the apex of the 10-mum-radius metal wire was electrochemically etched to an ultrafine point with a nanometer-radius, the metal wire was electrochemically coated with a phenol-allyphenol copolymer film. The micrometer-sized electrode was fabricated by directly electrochemical coating the metal wire with an extremely thin phenol-allyphenol copolymer film. Then, the nanometer-radius electrode (the first electrode) and the 10-mum-radius electrode (the second electrode) were inserted into two sides of a thick-septum borosilicate theta (theta) tubing, respectively. The second electrode protruded from the top of the theta tubing. The top of the theta tubing was sealed with insulating ethyl alpha-cyanoacrylate. The top of the theta tubing with both electrodes was ground flat and polished successively with fine sandpaper and aluminum oxide powder until the tip of the first electrode was exposed. Since the second electrode protruded from the top of the theta tubing, its 10-mum-radius tip was naturally formed during polishing. The dual-disk electrodes were characterized by scanning electron microscopy and cyclic voltammetry. The success rate for fabrication of the dual-disk electrodes is approximately 80% due to double insurance from two coating layers of different polymers. PMID:19073075

  6. Separatrix radius measurement of field-reversed configuration plasma in FRX-L

    SciTech Connect

    Zhang, S.Y.; Tejero, E.M.; Taccetti, J.M.; Wurden, G.A.; Intrator, T.P.; Waganaar, W.J.; Perkins, R.

    2004-10-01

    Magnetic pickup coils and single turn flux loops are installed on the FRX-L device. The combination of the two measurements provides the excluded flux radius that approximates the separatrix radius of the field-reversed configuration (FRC) plasma. Arrays of similar probes are used to map out local magnetic field dynamics beyond both ends of the theta-coil confinement region to help understand the effects of cusp locations on flux trapping during the FRC formation process. Details on the probe design and system calibrations are presented. The overall system calibration of excluded flux radius measurement is examined by replacing FRC plasma with a known radius aluminum conductor cylinder.

  7. On the critical flame radius and minimum ignition energy for spherical flame initiation

    SciTech Connect

    Chen, Zheng; Burke, M. P.; Ju, Yiguang

    2011-01-01

    Spherical flame initiation from an ignition kernel is studied theoretically and numerically using different fuel/oxygen/helium/argon mixtures (fuel: hydrogen, methane, and propane). The emphasis is placed on investigating the critical flame radius controlling spherical flame initiation and its correlation with the minimum ignition energy. It is found that the critical flame radius is different from the flame thickness and the flame ball radius and that their relationship depends strongly on the Lewis number. Three different flame regimes in terms of the Lewis number are observed and a new criterion for the critical flame radius is introduced. For mixtures with Lewis number larger than a critical Lewis number above unity, the critical flame radius is smaller than the flame ball radius but larger than the flame thickness. As a result, the minimum ignition energy can be substantially over-predicted (under-predicted) based on the flame ball radius (the flame thickness). The results also show that the minimum ignition energy for successful spherical flame initiation is proportional to the cube of the critical flame radius. Furthermore, preferential diffusion of heat and mass (i.e. the Lewis number effect) is found to play an important role in both spherical flame initiation and flame kernel evolution after ignition. It is shown that the critical flame radius and the minimum ignition energy increase significantly with the Lewis number. Therefore, for transportation fuels with large Lewis numbers, blending of small molecule fuels or thermal and catalytic cracking will significantly reduce the minimum ignition energy.

  8. Evaluation of the Proton Charge Radius from Electron–Proton Scattering

    SciTech Connect

    Arrington, John; Sick, Ingo

    2015-09-15

    In light of the proton radius puzzle, the discrepancy between measurements of the proton charge radius from muonic hydrogen and those from electronic hydrogen and electron–proton (e–p) scattering measurements, we re-examine the charge radius extractions from electron scattering measurements. We provide a recommended value for the proton root-mean-square charge radius, r{sub E} = 0.879 ± 0.011 fm, based on a global examination of elastic e–p scattering data. The uncertainties include contributions to account for tension between different data sets and inconsistencies between radii using different extraction procedures.

  9. Estimation of weapon-radius versus maneuverability trade-off for air-to-air combat

    NASA Technical Reports Server (NTRS)

    Kelley, H. J.; Lefton, L.

    1977-01-01

    A chase in a horizontal plane between a pursuer with a large capture radius and a more maneuverable evading vehicle is examined with constant-speed vehicle models. An approximation to the 'sidestepping' maneuver of the Homicidal Chauffeur Game is modified to account for the effect of evader turning rate, and an estimate of capture radius required is so obtained which agrees remarkably well with Cockayne's point-capture result. The maneuver assumes central importance for barrier surfaces appearing in the Game of Two Cars. Results are given for required weapon capture-radius in terms of the maneuverability of the two vehicles. Some calculations of capture radius are presented.

  10. Transosseous-Equivalent Repair for Distal Patellar Tendon Avulsion.

    PubMed

    Galos, David K; Konda, Sanjit R; Kaplan, Daniel J; Ryan, William E; Alaia, Michael J

    2016-04-01

    Extensor mechanism disruptions are relatively uncommon injuries involving injury to the quadriceps tendon, patella, or patellar tendon. Patellar tendon avulsions from the tibial tubercle in adults are rare; as such, little technical information has been written regarding surgical management of this injury in the adult. Transosseous-equivalent repairs have been described in the management of several types of tendon ruptures, including rotator cuff and distal triceps tendon ruptures, but not previously in patellar injuries. We present a technique for repairing an avulsion injury of the patellar tendon from the tibial tubercle using suture anchors in a transosseous-equivalent manner. This technique for treating distal patellar tendon avulsion injuries likely increases contact area at the repair site while potentially improving fixation strength. PMID:27462538

  11. Pendulum Therapy of Molar Distalization in Mixed Dentition

    PubMed Central

    Prakash, Amit; Agarwal, Anshu

    2016-01-01

    ABSTRACT Early and timely pedo-orthodontic treatment is aimed at eliminating the disturbances of skeletal or dentoalveolar development, to harmonize the stomatognathic system before the full eruption of all permanent teeth. The advantages of pendulum appliance are its minimal dependence on patient’s compliance (child cooperation), ease of fabrication, onetime activation and adjustment of the springs if necessary to correct minor transverse and vertical molar positions. This article reports a successful treatment method of class II malocclusion with pendulum appliance in mixed dentition phase. Distalization of maxillary molar was done, followed by guidance of canine impaction orthodontically and other dental correction using 0.022 MBT appliances. Posttreatment results were stable and remarkable. How to cite this article: Patil RU, Prakash A, Agarwal A. Pendulum Therapy of Molar Distalization in Mixed Dentition. Int J Clin Pediatr Dent 2016;9(1):67-73. PMID:27274159

  12. Pendulum Therapy of Molar Distalization in Mixed Dentition.

    PubMed

    Patil, Raju Umaji; Prakash, Amit; Agarwal, Anshu

    2016-01-01

    Early and timely pedo-orthodontic treatment is aimed at eliminating the disturbances of skeletal or dentoalveolar development, to harmonize the stomatognathic system before the full eruption of all permanent teeth. The advantages of pendulum appliance are its minimal dependence on patient's compliance (child cooperation), ease of fabrication, onetime activation and adjustment of the springs if necessary to correct minor transverse and vertical molar positions. This article reports a successful treatment method of class II malocclusion with pendulum appliance in mixed dentition phase. Distalization of maxillary molar was done, followed by guidance of canine impaction orthodontically and other dental correction using 0.022 MBT appliances. Posttreatment results were stable and remarkable. How to cite this article: Patil RU, Prakash A, Agarwal A. Pendulum Therapy of Molar Distalization in Mixed Dentition. Int J Clin Pediatr Dent 2016;9(1):67-73. PMID:27274159

  13. Pendulum Therapy of Molar Distalization in Mixed Dentition.

    PubMed

    Patil, Raju Umaji; Prakash, Amit; Agarwal, Anshu

    2016-01-01

    Early and timely pedo-orthodontic treatment is aimed at eliminating the disturbances of skeletal or dentoalveolar development, to harmonize the stomatognathic system before the full eruption of all permanent teeth. The advantages of pendulum appliance are its minimal dependence on patient's compliance (child cooperation), ease of fabrication, onetime activation and adjustment of the springs if necessary to correct minor transverse and vertical molar positions. This article reports a successful treatment method of class II malocclusion with pendulum appliance in mixed dentition phase. Distalization of maxillary molar was done, followed by guidance of canine impaction orthodontically and other dental correction using 0.022 MBT appliances. Posttreatment results were stable and remarkable. How to cite this article: Patil RU, Prakash A, Agarwal A. Pendulum Therapy of Molar Distalization in Mixed Dentition. Int J Clin Pediatr Dent 2016;9(1):67-73.

  14. Opening lines of communication in the distal nephron.

    PubMed

    Kleyman, Thomas R; Satlin, Lisa M; Hallows, Kenneth R

    2013-10-01

    The distal nephron is composed of two main cell types: principal cells and intercalated cells. These cells have distinct morphologic features that allow them to be readily distinguished by light microscopy, as well as distinct suites of proteins that facilitate cell-specific transport properties. In this issue of the JCI, Gueutin and colleagues describe a new mechanism by which β-intercalated cells, via release of ATP and prostaglandin E2 (PGE2), influence the activity of transporters in principal cells.

  15. Neural pattern in the human pollical distal phalanx.

    PubMed

    Johnson, Richard K; Shrewsbury, Marvin M

    2005-09-01

    A morphological study of the neural pattern in the human ungual region of the pollical distal phalanx was carried out on eight male cadavers. The dissections showed a palmar neural arrangement consisting of four designated ungual nerves, two proximal and two distal, for each of the ulnar and radial palmar digital nerves at the lateral sides of the thumb. This neural configuration was associated with the compartmentalization of its ungual pulp, the difference between the type of sensory receptors within the ungual pulp, the overlapping of the tactile composition at the thumb tip, seen clinically after laceration of one of the palmar digital nerves, and the sensory supply to the nail bed in the dorsal portion of the thumb. The proximal ungual pulp compartment had a single proximal medial ungual nerve, which did not appear, as far as visually possible, to overlap at the midline of the proximal ungual pulp. In contrast, the distal ungual pulp compartment was supplied by a medial and a lateral ungual nerve, both of which did appear to overlap to their contralateral sides in the thumb tip. A single proximal dorsal sensory nerve branched dorsally from each of ulnar and radial palmar digital nerves at the level of the proximal ungual pulp to supply the nail bed on the dorsum of the thumb.

  16. Early Distal Axonopathy of the Visual Pathway in Experimental Diabetes

    PubMed Central

    Fernandez, Diego C.; Pasquini, Laura A.; Dorfman, Damián; Aldana Marcos, Hernán J.; Rosenstein, Ruth E.

    2012-01-01

    Diabetic retinopathy is a leading cause of acquired blindness. Visual function disorders have been observed in diabetic patients with very early retinopathy or even before the onset of retinopathy. The aim of the present work was to analyze the visual pathway in an early stage of experimental diabetes. Diabetes was induced in Wistar rats by an i.p. injection of streptozotocin. A deficit in anterograde transport from the retina to the superior colliculus was observed 6 weeks after streptozotocin injection. At this time point, morphologic studies did not reveal retinal ganglion cell loss or substantial alterations in the superior colliculus. The optic nerve was morphometrically evaluated at intraorbital (unmyelinated and myelinated) and intracranial sections. In animals that had been diabetic for 6 weeks, a large increase in astrocyte reactivity occurred in the distal (but not the intraorbital) portion, which coincided with significant axon loss. Moreover, profound myelin alterations and altered morphologic features of oligodendrocyte lineage were observed at the distal (but not the proximal) optic nerve portion. The present results suggest that axoglial alterations at the distal portion of the optic nerve could be the first structural change in the diabetic visual pathway. PMID:22079928

  17. Distal histidine conformational flexibility in dehaloperoxidase from Amphitrite ornata

    SciTech Connect

    Chen, Zuxu; de Serrano, Vesna; Betts, Laurie; Franzen, Stefan

    2009-01-28

    The enzyme dehaloperoxidase (DHP) from the terebellid polychaete Amphitrite ornata is a heme protein which has a globin fold but can function as both a hemoglobin and a peroxidase. As a peroxidase, DHP is capable of converting 2,4,6-trihalophenols to the corresponding 2,6-dihaloquinones in the presence of hydrogen peroxide. As a hemoglobin, DHP cycles between the oxy and deoxy states as it reversibly binds oxygen for storage. Here, it is reported that the distal histidine, His55, exhibits conformational flexibility in the deoxy form and is consequently observed in two solvent-exposed conformations more than 9.5 {angstrom} away from the heme. These conformations are analogous to the open conformation of sperm whale myoglobin. The heme iron in deoxy ferrous DHP is five-coordinate and has an out-of-plane displacement of 0.25 {angstrom} from the heme plane. The observation of five-coordinate heme iron with His55 in a remote solvent-exposed conformation is consistent with the hypothesis that His55 interacts with heme iron ligands through hydrogen bonding in the closed conformation. Since His55 is also displaced by the binding of 4-iodophenol in an internal pocket, these results provide new insight into the correlation between heme iron ligation, molecular binding in the distal pocket and the conformation of the distal histidine in DHP.

  18. A novel, new robotic platform for natural orifice distal pancreatectomy.

    PubMed

    Thakkar, Shyam; Awad, Michael; Gurram, Krishna C; Tully, Steven; Wright, Cornell; Sanan, Siddharth; Choset, Howie

    2015-06-01

    Laparoendoscopic technology has revolutionized the practice of surgery; however, surgeons have not widely accepted laparoscopic techniques for pancreatic surgeries due to the complexity of the operation. Natural orifice transluminal endoscopic surgery (NOTES) offers a great new potential for pancreatic procedures, with early data showing benefits of reduced visible scarring and the potential for decreased wound infections, hernias, pain, and postoperative complications. However, there are significant limitations to the currently used flexible endoscopy tools, including a diminished visual field, spatial orientation and tissue manipulation issues, and 2-dimensional visual feedback. We have adopted a novel snake-like robot, the minimally invasive cardiac surgery (MICS) robot, which addresses these issues. In the current pilot study, the MICS robot was evaluated for transrectal distal pancreas exploration and resection in 2 nonsurvival porcine models. Abdominal navigation and accessing the pancreas was investigated in the first pig, and based on its success, pancreas resection was studied in pig 2. The MICS robot was successful in accessing and visualizing the right upper, left upper, and left lower quadrants of the abdomen in pig 1 and was able to perform a successful complex NOTES procedure with distal pancreas resection in pig 2, with only minimal laparoscopic retraction assistance. In conclusion, preliminary results showing the MICS robot in natural orifice distal pancreatectomy are positive. Enhancements to optics and instrumentation will help further increase the usability in pancreatic interventions. Future indications may include transgastric NOTES approaches, endoluminal procedures, and single-port applications.

  19. Corrective Osteotomy for Intra-Articular Distal Humerus Malunion

    PubMed Central

    Kinaci, Ahmet; Buijze, Geert A.; Leeuwen, Diederik H.van; Jupiter, Jesse B.; Marti, Rene K.; Kloen, Peter

    2016-01-01

    Background: An intra-articular distal humerus malunion can be disabling. To improve function, reduce pain and/or prevent further secondary osteoarthritis an intra-articular corrective osteotomy can be considered. Herein we present the indications, practical guidelines for pre- operative planning and surgical technique. Subsequently, we provide long-term results in a small series. Methods: We included six consecutive patients operated for intra-articular distal humerus malunion. Mean follow-up was 88 months. At lastest follow up elbow function was assessed according to standardized questionnaires and classification systems. Results: All six patients healed their osteotomies. Three patients had a postoperative complication which were treated succesfully. Range of motion improved significantly and all patients were satisfied with the outcome. The elbow performance scores were good to excellent in all. Correlation analyses showed that age and level of osteoarthritis are very strong predictors for the long-term elbow function and quality of life. Conclusion: An intra-articular corrective osteotomy for a malunited distal humerus fracture is a worthwhile procedure. Based on our results it should particularly be considered in young patients with minimal osteoarthritis and moderate to severe functional disability and/or pain. PMID:27200396

  20. Slipped Distal Femoral Epiphysis in Congenital Insensitivity to Pain

    PubMed Central

    Shaikh, M Javed; Rex, C; Vignesh, R; Chavan, Madhav

    2016-01-01

    Introduction: Congenital insensitivity to pain (CIP) is a rare disorder, and often presents to an orthopaedic surgeon as recurrent fractures, dislocations, pseudoarthrosis, osteomyelitis etc. Here, we report a case of congenital insensitivity to pain presenting with distal femoral physeal separation in a child. Case Report: A 12-year-old girl child came with complaints of limp while walking and swelling in the left knee for past 5 weeks. Mother gave a history that the girl is a known case of congenital insensitivity to pain with clear history of no pain on intramuscular injection since birth. She was born of consanguineous marriage and had no significant trauma, fever, other joint involvement or any features of rheumatism. On local examination, she had no bony tenderness, mild warmth, and moderate knee effusion with restricted range of movement. Plain radiograph showed epiphysiolysis of distal femur with widening of physis. Examination under anaesthesia demonstrated gross movement indicating lower femoral physeal separation. This unstable distal femoral epiphysis was treated under general anaesthesia with closed reduction, percutaneous cross pinning and above knee plaster cast. Conclusion: Congenital insensitivity to pain (CIP) is a rare disorder to diagnose. Emphasis is given on early diagnosis of orthopaedic problems and prompt treatment, educating parents and prevention of accidents. Physeal separation without significant trauma must prompt an orthopaedic surgeon to think about congenital insensitivity to pain as a differential diagnosis. PMID:27703943

  1. [Distal tibia peri-implant fracture with an intramedullary nail: a case report].

    PubMed

    Reyes-Cabrera, J M; González-Alconada, R; García-Mota, M D

    2013-01-01

    Peri-implant fractures of the distal tibia after intramedullary nailing are rare. We present a case of a fracture of the distal tibia at the site of the distal interlocking screw. We found two cases reported in the world literature. There are no cases reported in the Spanish literature.

  2. Avascular necrosis of the distal phalangeal epiphysis following physeal fracture: a case report.

    PubMed

    Nissenbaum, M

    1999-05-01

    Avascular necrosis of the distal phalangeal epiphysis following an unrecognized angulated Salter II fracture of the distal phalanx treated by open reduction and internal fixation resulted in premature closure of the growth plate and mild shortening. The epiphysis itself revascularized and good function of the distal interphalangeal joint was maintained.

  3. Successful Return to Sport Following Distal Femoral Varus Osteotomy

    PubMed Central

    Voleti, Pramod Babu; Degen, Ryan; Tetreault, Danielle; Krych, Aaron John; Williams, Riley J.

    2016-01-01

    Objectives: Distal femoral varus osteotomy is an effective treatment for unloading valgus knee malalignment; however, there is limited evidence on the ability for patients to return to athletics following this procedure. The purpose of this study is to report the functional outcomes and return to sport for athletic patients that underwent distal femoral varus osteotomy. Methods: A consecutive series of athletic patients that had undergone distal femoral varus osteotomy for symptomatic lateral compartment overload and valgus knee malalignment were prospectively reviewed. All patients had a minimum of 2-year follow-up. Radiographs were assessed to determine pre-operative and post-operative alignment. Details regarding sport of interest, ability to return to sport, and timing of return were obtained from the patients. Prospective institutional registries were utilized to collect pre-operative and post-operative Marx Activity Scale and International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC) scores; these values were compared using paired t-tests with p < 0.05 as the threshold for significance. Results: A total of 13 patients with a mean age of 24 years (range: 17-35) and a mean follow-up of 43 months (range: 24-74) were included in the study. Six patients underwent medial closing wedge osteotomy, and seven patients underwent lateral opening wedge osteotomy. The mean alignment correction was 8 degrees (range: 5-13). Nine patients underwent one or more concomitant procedures at the time of the osteotomy: 6 lateral femoral condyle osteochondral allografts, 2 partial lateral meniscectomies, 1 lateral meniscus allograft transplantation, and 1 revision anterior cruciate ligament reconstruction. All patients were able to successfully return to their sport of choice (4 soccer, 2 softball, 2 running, 1 football, 1 basketball, 1 ice hockey, 1 volleyball, 1 rowing) at a mean of 11 months (range: 9-13). Furthermore, all 13 patients demonstrated an

  4. Cholangiocarcinoma. A spectrum of intrahepatic, perihilar, and distal tumors.

    PubMed Central

    Nakeeb, A; Pitt, H A; Sohn, T A; Coleman, J; Abrams, R A; Piantadosi, S; Hruban, R H; Lillemoe, K D; Yeo, C J; Cameron, J L

    1996-01-01

    OBJECTIVE: The objective of this article is to introduce a simple method for classifying cholangiocarcinomas and to apply this system to analyze a large number of patients from a single institution. SUMMARY BACKGROUND DATA: For the past 2 decades, most western reports on cholangiocarcinoma have separated intrahepatic from extrahepatic tumors and have subclassified this latter group into proximal, middle, and distal subgroups. However, "middle" lesions are uncommon and are managed most often either with hilar resection or with pancreatoduodenectomy. The spectrum of cholangiocarcinoma, therefore, is best classified into three broad groups: 1) intrahepatic, 2) perihilar, and 3) distal tumors. These categories correlate with anatomic distribution and imply preferred treatment. METHODS: The records of all patients with histologically confirmed cholangiocarcinoma who underwent surgical exploration at The Johns Hopkins Hospital over a 23-year period were reviewed. RESULTS: Of 294 patients with cholangiocarcinoma, 18 (6%) had intrahepatic, 196 (67%) had perihilar, and 80 (27%) had distal tumors. Age, gender, race, and associated diseases were similar among the three groups. Patients with intrahepatic tumors, by definition, were less likely (p < 0.01) to be jaundiced and more likely (p < 0.05) to present with abdominal pain. The resectability rate increased with a more distal location (50% vs. 56% vs. 91%), and resection improved survival at each site. Five-year survival rates for resected intrahepatic, perihilar, and distal tumors were 44%, 11%, and 28%, and median survival rates were 26, 19, and 22 months, respectively. Postoperative radiation therapy did not improve survival. In a multivariate analysis resection (p < 0.001. hazard ratio 2.80), negative microscopic margins (p < 0.01, hazard ratio 1.79), preoperative serum albumin (p < 0.04, hazard ratio 0.82), and postoperative sepsis (p < 0.001, hard ratio 0.27) were the best predictors of outcome. CONCLUSIONS

  5. Measuring the Radius of the Earth from a Mountain Top Overlooking the Ocean

    ERIC Educational Resources Information Center

    Gangadharan, Dhevan

    2009-01-01

    A clear view of the ocean may be used to measure the radius of the Earth. To an observer looking out at the ocean, the horizon will always form some angle [theta] with the local horizontal plane. As the observer's elevation "h" increases, so does the angle [theta]. From measurements of the elevation "h" and the angle [theta], the radius "R" of the…

  6. Studying the proton 'radius' puzzle with μp elastic scattering

    SciTech Connect

    Gilman, R.

    2013-11-07

    The disagreement between the proton radius determined from muonic hydrogen and from electronic measurements is called the proton radius puzzle. The resolution of the puzzle remains unclear and appears to require new experimental results. An experiment to measure muon-proton elastic scattering is presented here.

  7. Comparison of dual protection and distal filter protection as a distal embolic protection method during carotid artery stenting: a single-center carotid artery stenting experience.

    PubMed

    Kajihara, Yosuke; Sakamoto, Shigeyuki; Kiura, Yoshihiro; Mukada, Kazutoshi; Chaki, Takahiro; Kajihara, Shiro; Kurisu, Kaoru

    2015-10-01

    There are several protection methods used to prevent distal embolism during carotid artery stenting (CAS). The aim of this study was to compare the dual protection method (proximal balloon and distal filter protection) with the distal filter protection during CAS performed at a single center. Between April 2008 and November 2013, 78 consecutive patients with internal carotid artery stenosis were treated with CAS at Istukaichi Memorial Hospital. Twenty-four consecutive patients were treated with CAS using distal filter protection (distal filter protection group), and 54 consecutive patients were treated with CAS using dual protection with a proximal balloon and distal filter protection (dual protection group). We examined the hyperintensity lesions on diffusion-weighted imaging (DWI) and perioperative complications after CAS. All stenotic lesions were successfully dilated. DWI showed hyperintensity lesions among 54.2 % (13/24 patients) in the distal filter protection group and in 27.8 % (15/54 patients) in the dual protection group (p = 0.024). The average number of hyperintensity lesions on DWI was 1.75 (range, 0 to 6) in the distal filter protection group and 0.59 (range, 0 to 5) in the dual protection group (p = 0.0087). Postprocedural persistent ischemic complications occurred in 4.2 % (1/24 patients) in the distal filter protection group and 3.7 % (2/54 patients) in the dual protection group (p = 0.67). In this study, the dual protection method reduced the number of hyperintensity lesions seen on DWI when compared with the distal filter protection method when used for distal embolic protection during CAS.

  8. Enchondroma in the distal phalanx of the finger

    PubMed Central

    Lu, Hui; Chen, Qiang; Yang, Hu; Shen, Hui

    2016-01-01

    Abstract The goal of our study was to report the clinical presentation, treatment, and complications of enchondroma in the distal phalanx of the finger. This was a retrospective study of 34 patients (19 women and 15 men) who underwent surgery between May 2004 and September 2012 for enchondroma in the distal phalanx of the finger. The average age of the patients was 39.38 ± 10.97 years old (range 14–59). The presenting symptoms and imaging features were recorded. The surgical procedure was performed under regional or general anesthesia. The surgical technique involved removal of tumors by opening a cortical window and curetting the cavity. The defects were filled with an injectable calcium phosphate cement. All patients received follow-up in our outpatient clinic every 6 months. Expansion of bone or thinning of the cortex present in the radiological imaging, including anteroposterior and lateral plain radiographs of the fingers, was used to assess for tumor recurrence. The observational end-point was reoperation. All tumors were confirmed as enchondromas by the pathological results. None of the patients had a tumor recurrence. Three patients (9% of cases) developed an infection. After antibiotic treatment, 2 patients were cured, and 1 patient required an amputation. Enchondroma in the distal phalanx of the finger presents with a variety of clinical symptoms. Injectable calcium phosphate cement is adequate for bone grafting. Postoperative infection is more common than tumor recurrence. If patients have an infection or bilateral bone cortex defects, bone grafting is challenging. Level of Evidence: Therapeutic study, Level IV PMID:27661057

  9. Temporary bridging external fixation in distal tibial fracture.

    PubMed

    Lavini, F; Dall'Oca, C; Mezzari, S; Maluta, T; Luminari, E; Perusi, F; Vecchini, E; Magnan, B

    2014-12-01

    Fractures that involve the distal area of the tibia are associated with a high percentage of complications. Soft tissue oedema, swelling, blisters, skin abrasions and open wounds could compromise the outcome of these lesions. The waiting time before surgery with ORIF is mostly due to soft tissue conditions. Early application of a simple joint-spanning external fixator would achieve the initial goal of stability and the respect of soft tissue, thereby decreasing the time necessary for definitive treatment. A total of 40 consecutive patients (22 male and 18 female) with a mean age of 52 years (range 17-82 years) with distal tibial fracture treated between January 2010 and January 2013 were evaluated. Early temporary external fixation was the first treatment step. Twenty patients had pilon fractures, characterised by the intra-articular involvement of the distal tibia with metaphyseal extension, and 20 patients had malleolar fracture-dislocation. Patients were divided into two groups, A and B. Group A comprised 10 patients with ankle fracture-dislocation and bone fragmentation, who were treated with a temporary bridging external fixation that was maintained after ORIF to exploit ligamentotaxis during the first phases of bone healing. In Group B (30 patients), the external fixation was removed after ORIF. The results of the study are in line with the recent literature: temporary external fixation in high-energy trauma and fracture-dislocation of the ankle enables soft tissue to be restored, which facilitates postoperative assessment of bone fragments by CT scan. The complication rate in this study was 5% in patients with malleolar fractures and 20% in patients with pilon fractures. The maintenance of temporary external fixation after ORIF synthesis during the entire first stage of bone healing seems to be a good method of treatment that has a low rate of soft tissue complications.

  10. Octreotide acetate inhibits motility in the rabbit distal colon.

    PubMed

    John, K D; Ballantyne, G H; Modlin, I M

    1997-01-01

    Octreotide, the long-acting somatostatin analogue, has been reported to modulate gastrointestinal motility in both animals and humans. A role in colonic peristalsis and a possible clinical application in common disorders, such as chronic constipation and irritable bowel syndrome, have not been evaluated. It has been previously suggested that octreotide promotes the descending relaxation of the peristaltic reflex arc. We hypothesized that this effect may involve inhibition of the motility index (MI) of the distal colon. To test this proposal, we studied peristalsis in isolated rabbit colons and also in the intact distal colons of anesthetized rabbits undergoing octreotide administration. Left colons of New Zealand white rabbits were harvested, placed in an isolated organ chamber and perfused with Krebs-Ringer bicarbonate solution via the inferior mesenteric artery. In a separate preparation, the colons were left in situ. Motility was quantified with a 6-port continuous infusion manometry catheter. The MI (mm Hg/min) was calculated by integration of the area of the digitalized signal (8/s), which reflected high-pressure peaks of different magnitudes. High-pressure waves were defined as > 20 mm Hg. Octreotide was infused via the inferior mesenteric artery in the isolated specimen or the lateral ear vein in the anesthetized animals in concentrations of 10(-12) to 10(-6) M. Octreotide inhibited high-pressure waves in a dose-dependent manner. These effects resulted in a decreased MI, with the maximum inhibition of 24.6% at 10(-11) M (p < 0.05 by ANOVA). At that concentration, the number of peaks > 20 mm Hg were reduced by 62.2%. The data indicate that octreotide decreases the MI by inhibition of high-pressure waves in the distal rabbit colon. These findings are consistent with the proposal that somatostatin may augment descending relaxation of the peristaltic reflex arc. This effect is independent of neural modulation.

  11. Fatigue - corrosion of endoprosthesis titanium alloys.

    PubMed

    Cornet, A; Muster, D; Jaeger, J H

    1979-01-01

    Commercial total hip prostheses often show certain metallurgical faults (porosities, coarse grains, growth dendrites, carbide networks). In order to investigate more accurately the role played by these different parameters in prostheses failure we performed a large number of systematic corrosion, fatigue and fatigue - corrosion tests on these materials and on commercial total hip prostheses. Ultimate strengthes seem to be reached for cast cobalt alloys, whereas titanium alloys, such as Ta 6 V, present very high fatigue limit under corrosion. Thus, rotative bending fatigue - corrosion tests in biological environment provide values about 50 DaN/mm2. This value, is nevertheless appreciably higher than those obtained with stellites and stainless steel. Titanium alloys, because of their mechanical performances, their weak Young's modulus (11000 DaN/mm2) and their relative lightness (4.5. g/cm3), which are associated with a good biocompatibility, seem very promising for permanent implants realisation.

  12. [Postoperative Osteomyelitis of a Distal Phalanx Caused by Raoultella ornithinolytica].

    PubMed

    Schmutz, N; Adler, T; Schelhorn, N; Wirz, S; Fricker, R

    2016-06-01

    We report on a case of osteomyelitis of a distal phalanx of the right ring finger of a 62-year-old patient, which occurred 11 months after transosseous-transungual refixation of a closed flexor digitorum profundus tendon avulsion caused by Raoultella ornithinolytica. R. ornithinolytica is an encapsulated Gram-negative aerobic bacillus. In the literature only 13 cases of human infection by R. ornithinolytica are mentioned. To the best of our knowledge, this is the first case of an osteomyelitis caused by R. ornithinolytica.

  13. Renal histology and immunopathology in distal renal tubular acidosis.

    PubMed

    Feest, T G; Lockwood, C M; Morley, A R; Uff, J S

    1978-11-01

    Renal biospy studies are reported from 10 patients with distal renal tubular acidosis (DRTA). On the biopsies from 6 patients who had associated immunological abnormalities immunofluorescent studies for immunoglobulins, complement, and fibrin were performed. Interstitial cellular infiltration and fibrosis were common findings in patients with and without immunological abnormalities, and were usually associated with nephrocalcinosis and/or recurrent urinary infection. No immune deposits were demonstrated in association with the renal tubules. This study shows that DRTA in immunologically abnormal patients is not caused by tubular deposition of antibody or immune complexes. The possibility of cell mediated immune damage is discussed.

  14. Primary Epiphyseal Aneurysmal Bone Cyst Of Distal Ulna

    PubMed Central

    Kapila, Rajesh; Sharma, Rakesh; Sohal, Yadwinder Singh; Singh, Dhalwinder; Singh, Sukhpal

    2015-01-01

    Introduction: Aneurysmal Bone Cyst (ABC) is a benign expansile cystic blood filled reactive lesion of the bone, most common in the first 2 decades of life. Though it can involve any bone in the body but tibia, humerus, femur and posterior elements of spine are most commonly affected. They most commonly involve metaphysis or metaphysio-diaphyseal part of the bone. Primary involvement of epiphysis is rarely reported. Here we present a case of 6 year old male child with an epiphyseal ABC of distal ulna. Its diagnosis, surgical management, clinical outcome with review of literature is discussed. PMID:27299110

  15. COUPLED EVOLUTION WITH TIDES OF THE RADIUS AND ORBIT OF TRANSITING GIANT PLANETS: GENERAL RESULTS

    SciTech Connect

    Ibgui, Laurent; Burrows, Adam E-mail: burrows@astro.princeton.edu

    2009-08-01

    Some transiting extrasolar giant planets (EGPs) have measured radii larger than predicted by the standard theory. In this paper, we explore the possibility that an earlier episode of tidal heating can explain such radius anomalies and apply the formalism we develop to HD 209458b as an example. We find that for strong enough tides the planet's radius can undergo a transient phase of inflation that temporarily interrupts canonical, monotonic shrinking due to radiative losses. Importantly, an earlier episode of tidal heating can result in a planet with an inflated radius, even though its orbit has nearly circularized. Moreover, we confirm that at late times, and under some circumstances, by raising tides on the star itself a planet can spiral into its host. We note that a 3x to 10x solar planet atmospheric opacity with no tidal heating is sufficient to explain the observed radius of HD 209458b. However, our model demonstrates that with an earlier phase of episodic tidal heating, we can fit the observed radius of HD 209458b even with lower (solar) atmospheric opacities. This work demonstrates that, if a planet is left with an appreciable eccentricity after early inward migration and/or dynamical interaction, coupling radius and orbit evolution in a consistent fashion that includes tidal heating, stellar irradiation, and detailed model atmospheres might offer a generic solution to the inflated radius puzzle for transiting EGPs such as WASP-12b, TrES-4, and WASP-6b.

  16. Effect of microstructure and notch root radius on fracture toughness of an aluminum metal matrix composite

    NASA Technical Reports Server (NTRS)

    Manoharan, M.; Lewandowski, J. J.

    1989-01-01

    Recent results on the effects of matrix aging condition (matrix temper) and notch root radius on the measured fracture toughness of a SiC particulate reinforced aluminum alloy are reviewed. Stress intensity factors at catastrophic fracture were obtained for both underaged and overaged composites reveal. The linear relation found between apparent fracture toughness and the square root of the notch root radius implies a linear dependence of the crack opening displacement on the notch root radius. The results suggest a strain controlled fracture process, and indicate that there are differences in the fracture micromechanisms of the two aging conditions.

  17. Comparison of continuous and discrete frequency-versus-radius frequency-modulated reticles.

    PubMed

    Taylor, J S; Driggers, R G; Halford, C E; Sanders, J S; Griffin, S T; Wellfare, M

    1992-04-01

    We present a general expression for the transmission function of the discrete frequency-versus-radius reticle and compare such a reticle with the more common continuous reticle. A discrete form of the frequency-versus-radius reticle has an integer number of chopping cycles on a single radius. The discreteform limits the resolution of the reticle in the radial direction, but this limit is not severe for small-target images. However, since no phase reversal occurs, electronic processing is simplified. PMID:20720799

  18. Linear stability of circular Couette flow in the limit of small radius ratio

    NASA Astrophysics Data System (ADS)

    Pearlstein, Arne J.

    2005-11-01

    In the context of a detailed study of the linear stability of spiral Poiseuille flow at small radius ratio (Cotrell and Pearlstein, J. Fluid Mech., in press), we have shown that in the limiting case of no rotation, annular Poiseuille flow is linearly stable at all Re, provided that the radius ratio lies below a critical value. Here, we consider the other limiting case, of no axial flow, and report a numerical investigation of the stability of circular Couette flow for small radius ratio. The results are compared to experimental work of Theodorsen for a whirling shaft in an unbounded, otherwise quiescent fluid.

  19. Mass-Radius Relationships for Low-Mass Planets: From Iron Planets to Water Planets

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2007-01-01

    Transit observations, and radial velocity measurements, have begun to populate the mass radius diagram for extrasolar planets; fubture astrometric measurements and direct images promise more mass and radius information. Clearly, the bulk density of a planet indicates something about a planet s composition--but what? I will attempt to answer this question in general for low-mass planets (radius relationship: an expansion whose first term is M approx. R(sup 3).

  20. A new method on measuring radius of curvature of a conic aspherical mirror

    NASA Astrophysics Data System (ADS)

    Huang, Chuan-ke; Wu, Yong-qian; Fan, Bin; Yan, Feng-tao; Liu, Feng-wei; Zhang, Yong-hong

    2014-09-01

    We present a method to measure the radius of curvature of a concave conic asphere. By analysis the central area of the asphere, we can measure the radius of an arbitrary point in the central area instead of the vertex of asphere. In the procedure, we firstly adjust the interferometer until the interferogram of the central area approach nulls, then put the laser tracker ball at the beam focus of the interferometer and move the tracker ball to touch the central area of the aspherical surface to get the two positions. With these measurement data, we can calculate the radius of curvature of the aspherical vertex and its uncertainty.

  1. Radius of the Sun from observations of the total solar eclipse of 31 July 1981.

    NASA Astrophysics Data System (ADS)

    Akimov, L. A.; Belkina, I. L.; Dyatel, N. P.; Marchenko, G. P.

    The moments of local contacts of 24 points on the east and west solar limbs are determined from the cinematographic solar continuum observations during the 31 July 1981 eclipse. The value of the solar radius averaged over limb regions with different activity was found by the least-squares method - rs = 959.97±0.04″ The solar radius estimates made separately for active and quiet limb regions reveal that the effect of active regions on the measured radius value is significant and may be as much as 0.14″

  2. Radius of the sun from observations of the total solar eclipse of July 31, 1981

    NASA Astrophysics Data System (ADS)

    Akimov, L. A.; Belkina, I. L.; Dyatel, N. P.; Marchenko, G. P.

    1993-06-01

    Moments of the local contacts at 24 points on E and W solar limbs are determined from the July 31, 1981 solar eclipse cinematographic observations in the continuum. The r.m.s. value of the solar radius, averaged over limb regions with different activity, is rs = 959.97 +/- 0.04 arcsec. The solar radius estimates made separately for limb active regions and for undisturbed ones demonstrated the significance of the active region effects on the measured solar radius (up to 0.14 arcsec).

  3. The distally based forearm island flap in hand reconstruction.

    PubMed

    Jeng, S F; Wei, F C

    1998-08-01

    The distally based forearm island flap is vascularized by the perforators of the distal radial artery. The skin flap is along the axis of the radial artery, and the pivot point of its subcutaneous pedicle is about 2 to 4 cm above the radial styloid process. We have treated 12 patients with 12 flaps for soft-tissue defects of the hand. Of these recipient sites, seven were in dorsal hands, two were in thumbs, two were in forearms, and one was in the palmar area. The donor-tissue variants included eight skin flaps, two adipofascial flaps, and two sensate flaps. The sizes of the flaps ranged from 6 x 4 cm to 14 x 6 cm. The donor site wound could be closed primarily in five patients. Two sensate flaps, innervated by the lateral antebrachial cutaneous nerve, could provide sensation for thumb reconstruction. The advantage of this flap is its constant and reliable blood supply without sacrifice of the main radial artery. The elevation of the flap is simple and rapid. There is the potential that this flap can be used as an innervated flap, and there is no need of microsurgical technique.

  4. Interactions between distal speech rate, linguistic knowledge, and speech environment.

    PubMed

    Morrill, Tuuli; Baese-Berk, Melissa; Heffner, Christopher; Dilley, Laura

    2015-10-01

    During lexical access, listeners use both signal-based and knowledge-based cues, and information from the linguistic context can affect the perception of acoustic speech information. Recent findings suggest that the various cues used in lexical access are implemented with flexibility and may be affected by information from the larger speech context. We conducted 2 experiments to examine effects of a signal-based cue (distal speech rate) and a knowledge-based cue (linguistic structure) on lexical perception. In Experiment 1, we manipulated distal speech rate in utterances where an acoustically ambiguous critical word was either obligatory for the utterance to be syntactically well formed (e.g., Conner knew that bread and butter (are) both in the pantry) or optional (e.g., Don must see the harbor (or) boats). In Experiment 2, we examined identical target utterances as in Experiment 1 but changed the distribution of linguistic structures in the fillers. The results of the 2 experiments demonstrate that speech rate and linguistic knowledge about critical word obligatoriness can both influence speech perception. In addition, it is possible to alter the strength of a signal-based cue by changing information in the speech environment. These results provide support for models of word segmentation that include flexible weighting of signal-based and knowledge-based cues.

  5. Functional and mechanistic diversity of distal transcription enhancers

    PubMed Central

    Bulger, Michael; Groudine, Mark

    2013-01-01

    Biological differences among metazoans, and between cell types in a given organism, arise in large part due to differences in gene expression patterns. The sequencing of multiple metazoan genomes, coupled with recent advances in genome-wide analysis of histone modifications and transcription factor binding, has revealed that among regulatory DNA sequences, gene-distal enhancers appear to exhibit the greatest diversity and cell-type specificity. Moreover, such elements are emerging as important targets for mutations that can give rise to disease and to genetic variability that underlies evolutionary change. Studies of long-range interactions between distal genomic sequences in the nucleus indicate that enhancers are often important determinants of nuclear organization, contributing to a general model for enhancer function that involves direct enhancer-promoter contact. In a number of systems, however, mechanisms for enhancer function are emerging that do not fit solely within such a model, suggesting that enhancers as a class of DNA regulatory element may be functionally and mechanistically diverse. PMID:21295696

  6. Distal coronary artery perfusion during percutaneous transluminal coronary angioplasty.

    PubMed

    Anderson, H V; Leimgruber, P P; Roubin, G S; Nelson, D L; Gruentzig, A R

    1985-10-01

    Perfusion of the coronary artery distal to an occluding angioplasty balloon was performed in 34 patients undergoing coronary angioplasty (PTCA). A randomized crossover study was employed using two exogenous substances as perfusates: lactated Ringer's solution (LR) and a fluorocarbon emulsion (FL), Fluosol-DA 20%. Both substances are electrolyte solutions, but the FL will dissolve more oxygen than the LR. During two attempted coronary artery occlusions of 90 seconds each, we perfused through the central lumen (guidewire channel) of the PTCA catheter at 60 ml/min. With FL perfusion the mean time to onset of angina after occlusion was delayed (41 +/- 21 vs 33 +/- 16 seconds, mean +/- SD; p less than 0.05), the mean duration of angina was shortened (77 +/- 58 vs 92 +/- 70 seconds, p less than 0.05), and the rise in the ST segment of the ECG was reduced (0.15 +/- 0.24 vs 0.2 +/- 0.23 mV, p less than 0.001) when compared to LR perfusion. Balloon occlusion time was able to be extended with FL perfusion (71 +/- 22 vs 59 +/- 22 seconds p less than 0.001). These results indicate that perfusion of the distal coronary artery is possible during PTCA and can reduce ischemia during a prolonged balloon occlusion time. PMID:2931968

  7. Florid reactive periostitis ossificans of the distal ulna.

    PubMed

    Porcel López, M T; Fernández Gil, M A; Campos de Orellana, A; Quiles Galindo, M

    2008-03-01

    Florid reactive periostitis is the term used to describe a benign disease characterized by aggressive periosteal reaction and benign soft-tissue inflammation. Although it is considered rare, there are numerous reports in the literature that refer to this disease with different names such as parosteal fasciitis, fasciitis ossificans, benign fibro-osseous pseudotumor, pseudomalignant osseous tumor of soft tissue, and bizarre parosteal osteochondromatous proliferation. As a result, the nomenclature is confusing, and some authors have placed florid reactive periostitis ossificans into the heterogeneous group of pseudomalignant osseous tumors of soft tissue or proliferative periosteal processes, whereas other authors place this entity in the myositis ossificans group. In the same manner, florid reactive periostitis has been considered to be a previous stage of bizarre parosteal osteochondromatous proliferations. This article presents a case of florid reactive periostitis ossificans of the distal ulna in a 13-year-old boy. The patient presented with a painful lesion in the distal ulna, and plain radiographs suggested the presence of a quickly growing periosteal lesion with associated calcification and soft tissue mass. Histologically, the appearance was that of reactive periostitis. The clinical, radiological, and histologic features of florid reactive periostitis are described.

  8. Tarui disease and distal glycogenoses: clinical and genetic update.

    PubMed

    Toscano, A; Musumeci, O

    2007-10-01

    Phosphofructokinase deficiency (Tarui disease) was the first disorder recognized to directly affect glycolysis. Since the discovery of the disease, in 1965, a wide range of biochemical, physiological and molecular studies have greatly contributed to our knowledge concerning not only phosphofructokinase function in normal muscle but also on the general control of glycolysis and glycogen metabolism. Studies on phosphofructokinase deficiency vastly enriched the field of glycogen storage diseases, making a relevant improvement also in the molecular genetic area. So far, more than one hundred patients have been described with prominent clinical symptoms characterized by muscle cramps, exercise intolerance, rhabdomyolysis and myoglobinuria, often associated with haemolytic anaemia and hyperuricaemia. The muscle phosphofructokinase gene is located on chromosome 12 and about 20 mutations have been described. Other glycogenoses have been recognised in the distal part of the glycolytic pathway: these are infrequent but some may induce muscle cramps, exercise intolerance and rhabdomyolysis. Phosphoglycerate Kinase, Phosphoglycerate Mutase, Lactate Dehydrogenase, beta-Enolase and Aldolase A deficiencies have been described as distal glycogenoses. From the molecular point of view, the majority of these enzyme deficiencies are sustained by "private" mutations. PMID:18421897

  9. Design of roundness measurement model with multi-systematic error for cylindrical components with large radius.

    PubMed

    Sun, Chuanzhi; Wang, Lei; Tan, Jiubin; Zhao, Bo; Tang, Yangchao

    2016-02-01

    The paper designs a roundness measurement model with multi-systematic error, which takes eccentricity, probe offset, radius of tip head of probe, and tilt error into account for roundness measurement of cylindrical components. The effects of the systematic errors and radius of components are analysed in the roundness measurement. The proposed method is built on the instrument with a high precision rotating spindle. The effectiveness of the proposed method is verified by experiment with the standard cylindrical component, which is measured on a roundness measuring machine. Compared to the traditional limacon measurement model, the accuracy of roundness measurement can be increased by about 2.2 μm using the proposed roundness measurement model for the object with a large radius of around 37 mm. The proposed method can improve the accuracy of roundness measurement and can be used for error separation, calibration, and comparison, especially for cylindrical components with a large radius. PMID:26931894

  10. Reynolds Number Effects on Leading Edge Radius Variations of a Supersonic Transport at Transonic Conditions

    NASA Technical Reports Server (NTRS)

    Rivers, S. M. B.; Wahls, R. A.; Owens, L. R.

    2001-01-01

    A computational study focused on leading-edge radius effects and associated Reynolds number sensitivity for a High Speed Civil Transport configuration at transonic conditions was conducted as part of NASA's High Speed Research Program. The primary purposes were to assess the capabilities of computational fluid dynamics to predict Reynolds number effects for a range of leading-edge radius distributions on a second-generation supersonic transport configuration, and to evaluate the potential performance benefits of each at the transonic cruise condition. Five leading-edge radius distributions are described, and the potential performance benefit including the Reynolds number sensitivity for each is presented. Computational results for two leading-edge radius distributions are compared with experimental results acquired in the National Transonic Facility over a broad Reynolds number range.

  11. Radiation Power Affected by Current and Wall Radius in Water Cooled Vortex Wall-stabilized Arc

    NASA Astrophysics Data System (ADS)

    Iwao, Toru; Nakamura, Takaya; Yanagi, Kentaro; Yamamoto, Shinji

    2015-11-01

    The arc lighting to obtain the environment to evacuate, save the life, keep the safety and be comfortable are focus on. The lack of radiation intensity and color rendering is problem because of inappropriate energy balance. Some researchers have researched the arc lamp mixed with metal vapor for improvement of color rendering spectrum. The metal vapor can emit the high intense radiation. In addition, the radiation is derived from the high temperature medium. Because the arc temperature can be controlled by current and arc radius, the radiation can be controlled by the current and arc radius. This research elucidates the radiation power affected by the current and wall radius in wall-stabilized arc of water-cooled vortex type. As a result, the radiation power increases with increasing the square of current / square of wall radius because of the temperature distribution which is derived from the current density at the simulation.

  12. Method for Determining the Radius Vector for a Planet from Two Observations of Position

    ERIC Educational Resources Information Center

    Gainer, Michael Kizinski

    1977-01-01

    Presents a method for determining the approximate radius vector of a planet or asteroid from two closely separated observation positions, using mathematics suitable for lower division college students. (MLH)

  13. Self-equilibration of the radius distribution in self-catalyzed GaAs nanowires

    NASA Astrophysics Data System (ADS)

    Leshchenko, E. D.; Turchina, M. A.; Dubrovskii, V. G.

    2016-08-01

    This work addresses the evolution of radius distribution function in self-catalyzed vapor-liquid-solid growth of GaAs nanowires from Ga droplets. Different growth regimes are analyzed depending on the V/III flux ratio. In particular, we find a very unusual selfequilibration regime in which the radius distribution narrows up to a certain stationary radius regardless of the initial size distribution of Ga droplets. This requires that the arsenic vapor flux is larger than the gallium one and that the V/III influx imbalance is compensated by a diffusion flux of gallium adatoms. Approximate analytical solution is compared to the numerical radius distribution obtained by solving the corresponding Fokker-Planck equation by the implicit difference scheme.

  14. Radius construction and structure in the orb-web of Zilla diodia (Araneidae).

    PubMed

    Zschokke, S

    2000-10-01

    In orb-webs, the tension of the sticky spiral produces a centripetal force on the radii, resulting in an increase in tension along each radius from the centre of the web to the periphery. Zilla diodia (Walckenaer, 1802) atypical of araneids, was found to adapt the structure of its radii to this tension gradient by building radii that are double stranded at the periphery of the web and single stranded near the centre. Furthermore, the proportion of each radius that is doubled was found to be larger in the upper part of the web - where the overall tensions in the radii are known to be higher than in the lower part of the web. suggesting that the spider adjusts the proportion of each radius that is doubled to the overall tension in the radius. PMID:11138801

  15. Radius of Curvature of the Cornea--An Experiment for the Life-Science Physics Lab

    ERIC Educational Resources Information Center

    MacLatchy, C. S.

    1978-01-01

    Presents a quantitative laboratory experiment in geometrical optics. It involves the student in the measurement of the radius of curvature of the cornea and is based on an old method devised by Kohlrausch in 1839. (Author/GA)

  16. Using a video camera to measure the radius of the Earth

    NASA Astrophysics Data System (ADS)

    Carroll, Joshua; Hughes, Stephen

    2013-11-01

    A simple but accurate method for measuring the Earth’s radius using a video camera is described. A video camera was used to capture a shadow rising up the wall of a tall building at sunset. A free program called ImageJ was used to measure the time it took the shadow to rise a known distance up the building. The time, distance and length of the sidereal day were used to calculate the radius of the Earth. The radius was measured as 6394.3 ± 118 km, which is within 1.8% of the accepted average value of 6371 km and well within the experimental error. The experiment is suitable as a high school or university project and should produce a value for Earth’s radius within a few per cent at latitudes towards the equator, where at some times of the year the ecliptic is approximately normal to the horizon.

  17. Effective charge and effective radius of water droplet in dropwise cluster

    SciTech Connect

    Shavlov, A. V.; Romanyuk, S. N.; Dzhumandzhi, V. A.

    2013-02-15

    A particle with large electric charge Z (Z Much-Greater-Than 1) and radius R{sub 0} inserted into plasma is surrounded by a plasma shell, which is stable to weak and short-term external exposures. As a result, during experiments the particle can reveal an effective charge Z* lower than the true one (Z*{<=} Z), and an effective radius R* larger than the true one (R*{>=} R{sub 0}). The effective electric charge and the effective radius of a water droplet in a dropwise cluster have been calculated using the Poisson-Boltzmann equation. It has been recognized that these parameters are not the function of a droplet's true charge, but are the function of a droplet's true size and the Debye's radius of the plasma. Experimental data on the droplet properties in a dropwise cluster have been explained.

  18. Ionic Radius: Its Development and Use in the Teaching of Inorganic Chemistry.

    ERIC Educational Resources Information Center

    Lewis, J. I; Waddling, R. E. L.

    1986-01-01

    The topic of ionic radius is generally given scant treatment in modern textbooks. Therefore, this article reviews some historical work and illustrates some of the applications of ionic radii in the teaching of inorganic chemistry. (JN)

  19. Reverberation measurements of the inner radius of the dust torus in 17 Seyfert galaxies

    SciTech Connect

    Koshida, Shintaro; Minezaki, Takeo; Yoshii, Yuzuru; Sakata, Yu; Sugawara, Shota; Kobayashi, Yukiyasu; Suganuma, Masahiro; Enya, Keigo; Tomita, Hiroyuki; Aoki, Tsutomu; Peterson, Bruce A. E-mail: minezaki@ioa.s.u-tokyo.ac.jp

    2014-06-20

    We present the results of a dust reverberation survey for 17 nearby Seyfert 1 galaxies, which provides the largest homogeneous data collection for the radius of the innermost dust torus. A delayed response of the K-band light curve after the V-band light curve was found for all targets, and 49 measurements of lag times between the flux variation of the dust emission in the K band and that of the optical continuum emission in the V band were obtained by the cross-correlation function analysis and also by an alternative method for estimating the maximum likelihood lag. The lag times strongly correlated with the optical luminosity in the luminosity range of M{sub V} = –16 to –22 mag, and the regression analysis was performed to obtain the correlation log Δt (days) = –2.11 – 0.2 M{sub V} assuming Δt∝L {sup 0.5}, which was theoretically expected. We discuss the possible origins of the intrinsic scatter of the dust lag-luminosity correlation, which was estimated to be approximately 0.13 dex, and we find that the difference of internal extinction and delayed response of changes in lag times to the flux variations could have partly contributed to intrinsic scatter. However, we could not detect any systematic change of the correlation with the subclass of the Seyfert type or the Eddington ratio. Finally, we compare the dust reverberation radius with the near-infrared interferometric radius of the dust torus and the reverberation radius of broad Balmer emission lines. The interferometric radius in the K band was found to be systematically larger than the dust reverberation radius in the same band by the about a factor of two, which could be interpreted by the difference between the flux-weighted radius and response-weighted radius of the innermost dust torus. The reverberation radius of the broad Balmer emission lines was found to be systematically smaller than the dust reverberation radius by about a factor of four to five, which strongly supports the unified

  20. Critical loss radius in a Penning trap subject to multipole fields

    SciTech Connect

    Fajans, J.; Madsen, N.; Robicheaux, F.

    2008-03-15

    When particles in a Penning trap are subject to a magnetic multipole field, those beyond a critical radius will be lost. The critical radius depends on the history by which the field is applied, and can be much smaller if the particles are injected into a preexisting multipole than if the particles are subject to a ramped multipole. Both cases are relevant to ongoing experiments designed to trap antihydrogen.

  1. A method for measuring the radius of curvature of a spherical mirror

    NASA Astrophysics Data System (ADS)

    Engelen, J.; El-Zaiat, S. Y.; Missotten, L.

    1992-01-01

    Evan's method for measuring the radius of curvature of both convex and concave spherical mirrors is adapted and applied. The optical set-up is modified by adding a beam splitter, and a screen with two pinholes at a distance d apart. The laser source and the mirror under test remain fixed; this greatly facilitates the displacement measurements. The quartic equation of which one of the roots gives the radius of curvature of the mirror under test is derived without approximation.

  2. Hubble Space Telescope secondary mirror vertex radius/conic constant test

    NASA Technical Reports Server (NTRS)

    Parks, Robert

    1991-01-01

    The Hubble Space Telescope backup secondary mirror was tested to determine the vertex radius and conic constant. Three completely independent tests (to the same procedure) were performed. Similar measurements in the three tests were highly consistent. The values obtained for the vertex radius and conic constant were the nominal design values within the error bars associated with the tests. Visual examination of the interferometric data did not show any measurable zonal figure error in the secondary mirror.

  3. Involvement of dachshund and Distal-less in distal pattern formation of the cricket leg during regeneration

    PubMed Central

    Ishimaru, Yoshiyasu; Nakamura, Taro; Bando, Tetsuya; Matsuoka, Yuji; Ohuchi, Hideyo; Noji, Sumihare; Mito, Taro

    2015-01-01

    Cricket nymphs have the remarkable ability to regenerate a functional leg following amputation, indicating that the regenerating blastemal cells contain information for leg morphology. However, the molecular mechanisms that underlie regeneration of leg patterns remain poorly understood. Here, we analyzed phenotypes of the tibia and tarsus (three tarsomeres) obtained by knockdown with regeneration-dependent RNA interference (rdRNAi) against Gryllus dachshund (Gb'dac) and Distal-less (Gb'Dll). We found that depletion of Gb'Dll mRNA results in loss of the tarsal segments, while rdRNAi against Gb'dac shortens the tibia at the two most distal tarsomeres. These results indicate that Gb'Dll expression is indispensable for formation of the tarsus, while Gb'dac expression is necessary for elongation of the tibia and formation of the most proximal tarsomere. These findings demonstrate that mutual transcriptional regulation between the two is indispensable for formation of the tarsomeres, whereas Gb'dac is involved in determination of tibial size through interaction with Gb'ds/Gb'ft. PMID:25669615

  4. Measurement of super large radius optics in the detection of gravitational waves

    NASA Astrophysics Data System (ADS)

    Yang, Cheng; Han, Sen; Wu, Quanying; Liang, Binming; Hou, Changlun

    2015-10-01

    The existence of Gravitational Wave (GW) is one of the greatest predictions of Einstein's relative theory. It has played an important part in the radiation theory, black hole theory, space explore and so on. The GW detection has been an important aspect of modern physics. With the research proceeding further, there are still a lot of challenges existing in the interferometer which is the key instrument in GW detection especially the measurement of the super large radius optics. To solve this problem, one solution , Fizeau interference, for measuring the super large radius has been presented. We change the tradition that curved surface must be measured with a standard curved surface. We use a flat mirror as a reference flat and it can lower both the cost and the test requirement a lot. We select a concave mirror with the radius of 1600mm as a sample. After the precision measurement and analysis, the experimental results show that the relative error of radius is better than 3%, and it can fully meet the requirements of the measurement of super large radius optics. When calculating each pixel with standard cylinder, the edges are not sharp because of diffraction or some other reasons, we detect the edge and calculate the diameter of the cylinder automatically, and it can improve the precision a lot. In general, this method is simple, fast, non-traumatic, and highly precision, it can also provide us a new though in the measurement of super large radius optics.

  5. Effects of corner radius on periodic nanoantenna for surface-enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Chao, Bo-Kai; Lin, Shih-Che; Nien, Li-Wei; Li, Jia-Han; Hsueh, Chun-Hway

    2015-12-01

    Corner radius is a concept to approximate the fabrication limitation due to the effective beam broadening at the corner in using electron-beam lithography. The purpose of the present study is to investigate the effects of corner radius on the electromagnetic field enhancement and resonance wavelength for three periodic polygon dimers of bowtie, twin square, and twin pentagon. The enhancement factor of surface-enhanced Raman spectroscopy due to the localized surface plasmon resonances in fabricated gold bowtie nanostructures was investigated using both Raman spectroscopy and finite-difference time-domain simulations. The simulated enhancement factor versus corner radius relation was in agreement with measurements and it could be fitted by a power-law relation. In addition, the resonance wavelength showed blue shift with the increasing corner radius because of the distribution of concentrated charges in a larger area. For different polygons, the corner radius instead of the tip angle is the dominant factor of the electromagnetic field enhancement because the surface charges tend to localize at the corner. Greater enhancements can be obtained by having both the smaller gap and sharper corner although the corner radius effect on intensity enhancement is less than the gap size effect.

  6. [Treatment of distal ureteral calculi with extracorporeal shockwave lithotripsy: experiences with 310 cases].

    PubMed

    Zehntner, C; Lux, O; Casanova, G A; Marth, D; Zingg, E J

    1989-07-01

    Distal ureteral calculi are approached by ureterorenoscopy by most authors. With increasing experience ESWL of distal ureteral calculi gained in importance. The success rate of 96.2% in a large series of 310 consecutive patients treated in this manner, confirmed the results of other authors. Excluding women of child-bearing age and very large calculi (greater than 2 cm) the ESWL is a suitable treatment modality of distal ureteral calculi.

  7. Total distalization of the maxillary arch in a patient with skeletal Class II malocclusion.

    PubMed

    Choi, Yoon Jeong; Lee, Jong-Suk; Cha, Jung-Yul; Park, Young-Chel

    2011-06-01

    In nongrowing patients with skeletal Class II malocclusion, premolar extraction or maxillary molar distalization can be used as camouflage treatment. Orthodontic miniscrew implants are widely used for this purpose because they do not produce undesirable reciprocal effects and do not depend on the patient's cooperation. This article reports on maxillary molar distalization by using miniscrew implants to correct a Class II problem. The main considerations of molar distalization treatment with miniscrew implants are discussed. PMID:21640890

  8. In vivo assessment of architecture and micro-finite element analysis derived indices of mechanical properties of trabecular bone in the radius.

    PubMed

    Newitt, D C; Majumdar, S; van Rietbergen, B; von Ingersleben, G; Harris, S T; Genant, H K; Chesnut, C; Garnero, P; MacDonald, B

    2002-01-01

    Measurement of microstructural parameters of trabecular bone noninvasively in vivo is possible with high-resolution magnetic resonance (MR) imaging. These measurements may prove useful in the determination of bone strength and fracture risk, but must be related to other measures of bone properties. In this study in vivo MR imaging was used to derive trabecular bone structure measures and combined with micro-finite element analysis (microFE) to determine the effects of trabecular bone microarchitecture on bone mechanical properties in the distal radius. The subjects were studied in two groups: (I) postmenopausal women with normal bone mineral density (BMD) (n = 22, mean age 58 +/- 7 years) and (II) postmenopausal women with spine or femur BMD -1 SD to -2.5 SD below young normal (n = 37, mean age 62 +/- 11 years). MR images of the distal radius were obtained at 1.5 T, and measures such as apparent trabecular bone volume fraction (App BV/TV), spacing, number and thickness (App TbSp, TbN, TbTh) were derived in regions of interest extending from the joint line to the radial shaft. The high-resolution images were also used in a micro-finite element model to derive the directional Young's moduli (E1, E2 and E3), shear moduli (G12, G23 and G13) and anisotropy ratios such as E1/E3. BMD at the distal radius, lumbar spine and hip were assessed using dual-energy X-ray absorptiometry (DXA). Bone formation was assessed by serum osteocalcin and bone resorption by serum type I collagen C-terminal telopeptide breakdown products (serum CTX) and urinary CTX biochemical markers. The trabecular architecture displayed considerable anisotropy. Measures of BMD such as the ultradistal radial BMD were lower in the osteopenic group (p<0.01). Biochemical markers between the two groups were comparable in value and showed no significant difference between the two groups. App BV/TV, TbTh and TbN were higher, and App TbSp lower, in the normal group than the osteopenic group. All three directional

  9. Preventing distal voids during cementation of the femoral component in total hip arthroplasty.

    PubMed

    Berger, R A; Steel, M J; Schleiden, M; Rubash, H E

    1993-06-01

    Cement voids have been noted in close approximation to the unfilled hole in the distal end of the femoral prosthesis. These cement voids result from the displacement of cement by the expansion of air trapped in the distal prosthesis. Voids in the distal cement have been shown to lead to an increased incidence of cement failures. This potentially deleterious situation can easily be avoided by plugging the hole in the distal stem. This may be accomplished three ways: using a centralizer, using the plastic plug supplied with the prosthesis, or filling the hole with cement prior to implanting the prosthesis. PMID:8326315

  10. Morphometric variation in Plio-Pleistocene hominid distal humeri.

    PubMed

    Lague, M R; Jungers, W L

    1996-11-01

    The magnitude and meaning of morphological variation among Plio-Pleistocene hominid distal humeri have been recurrent points of disagreement among paleoanthropologists. Some researchers have found noteworthy differences among fossil humeri that they believe merit taxonomic separation, while others question the possibility of accurately sorting these fossils into different species and/or functional groups. Size and shape differences among fossil distal humeri are evaluated here to determine whether the magnitude and patterns of these differences can be observed within large-bodied, living hominoids. Specimens analyzed in this study have been assigned to various taxa (Australopithecus afarensis, A. africanus, A. anamensis, Paranthropus, and early Homo) and include AL 288-1m, AL 288-1s, AL 137-48a, AL 322-1, Gomboré IB 7594, TM 1517, KNM-ER 739, KNM-ER 1504, KMN-KP 271 (Kanapoi), and Stw 431. Five extant hominoid populations are sampled to provide a standard by which to consider differences found between the fossils, including two modern human groups (Native American and African American), one group of Pan troglodytes, and two subspecies of Gorilla gorilla (G.g. beringei, G.g. gorilla). All possible pairwise d values (average Euclidena distances) are calculated within each of the reference populations using an exact randomization procedure. This is done using both raw linear measurements as well as scale-free shape data created as ratios of each measurement to the geometric mean. Differences between each pair of fossil humeri are evaluated by comparing their d values to the distribution of d values found within each of the reference populations. Principal coordinate analysis and an unweighted pair group method with arithmetic averages (UPGMA) cluster analysis are utilized to further assess similarities and differences among the fossils. Finally, canonical variates analysis and discriminant analysis are employed using all hominoid samples in order to control for

  11. Distal ventriculoperitoneal shunt failure caused by silicone allergy. Case report.

    PubMed

    Hussain, Namath S; Wang, Paul P; James, Carol; Carson, Benjamin S; Avellino, Anthony M

    2005-03-01

    The placement of a ventriculoperitoneal (VP) shunt is the most common form of treatment for hydrocephalus. Although allergic reactions to the silicone in shunt hardware are very rare, the authors describe a case of silicone allergy causing multiple ventricular shunt revisions. A 24-year-old man, who had undergone multiple VP shunt revisions, presented with shunt malfunction caused by allergic reaction of the tissues surrounding the shunt tubing. The patient's existing silicone-based shunt was replaced with a new polyurethane system, including the proximal and distal catheters as well as the valve mechanism. Contrary to recommendations in previous studies of silicone shunt allergies, long-term immunosuppression was not initiated. The patient was followed up for more than 8 years without recurrence of an allergic reaction to the shunt. This outcome indicates that replacing the original silicone-based shunt system with a polyurethane-based system alone is sufficient in the treatment of a silicone shunt allergy.

  12. Sphincter-saving procedures for distal carcinoma of the rectum.

    PubMed Central

    Yeatman, T J; Bland, K I

    1989-01-01

    Methods of sphincter preservation were developed more than a century ago. Combining these techniques with adequate anterior resection has permitted the resurrection of sphincter-saving procedures that are currently being applied in the therapy of cancer at every level of the rectum. Although Miles' abdominoperineal resection still remains the "gold standard" for the treatment of low rectal neoplasms, restorative resection may now be possible with equivalent oncologic disease control and survival. Further, current trends also suggest that the abdominoperineal resection is being used less frequently in the treatment of most rectal cancers and is being replaced with sphincter-preserving techniques that afford excellent functional results. In this review, the pertinent anorectal anatomy, current issues, and sphincter-saving surgical techniques presently available for the treatment of distal cancers of the rectum are presented. PMID:2642688

  13. Laing distal myopathy pathologically resembling inclusion body myositis

    PubMed Central

    Roda, Ricardo H; Schindler, Alice B; Blackstone, Craig; Mammen, Andrew L; Corse, Andrea M; Lloyd, Thomas E

    2014-01-01

    Mutations in MYH7 cause autosomal dominant Laing distal myopathy. We present a family with a previously reported deletion (c.5186_5188delAGA, p.K1729del). Muscle pathology in one family member was characterized by an inflammatory myopathy with rimmed vacuoles, increased MHC Class I expression, and perivascular and endomysial muscle inflammation comprising CD3+, CD4+, CD8+, and CD68+ inflammatory cells. Interestingly, this biopsy specimen contained TDP-43, p62, and SMI-31-positive protein aggregates typical of inclusion body myositis. These findings should alert physicians to the possibility that patients with MYH7 mutations may have muscle biopsies showing pathologic findings similar to inclusion body myositis. PMID:25574480

  14. Cutaneous Mycobacterium chelonae infection distal to the arteriovenous fistula

    PubMed Central

    Van Ende, Charlotte; Wilmes, Dunja; Lecouvet, Frédéric E.; Labriola, Laura; Cuvelier, René; Van Ingelgem, Grégory; Jadoul, Michel

    2016-01-01

    A few single cases of Mycobacterium chelonae skin infection have been reported in haemodialysis patients. We report three additional cases that share peculiar clinical characteristics, pointing to diagnostic clues. All three cases presented as erythematous nodules developing distally to a proximal arteriovenous fistula (AVF). This presentation was identical to that of two published cases. A survey of all Belgian haemodialysis units during the period 2007–11 yields an estimated incidence of ∼0.9/10 000 patient-years. Although the source of M. chelonae remains unclear, this specific clinical presentation should be added to the listing of potential complications of an AVF and should be recognized, as it is fully treatable if diagnosed by culture and tissue biopsy. PMID:27679721

  15. [Splanchnic circulation after distal splenorenal anastomosis in hepatic cirrhosis].

    PubMed

    Shalimov, A A; Kalita, N Ia; Kotenko, O G; Andreeshchev, S A

    1999-01-01

    While the result estimation of the distal splenorenal anastomosis formation operation, done in 12 patients according to the W. D. Warren method and in another 12 patients--according to the method, modified by K. Inokuchi, it was established that the hepatic portal perfusion loss causes compensational enhancement of blood flow in a. hepatica, including while the standard method application--by 22% and the modified one--by 8%. Doing the splenorenal venous disconnection improves the patients' quality of life due to the incidence rate of portosystemic encephalopathy reduction by 8.3%, and in this circumstances the life span and the hemorrhage recurrency rate do not differ with such while using the standard method.

  16. Cutaneous Mycobacterium chelonae infection distal to the arteriovenous fistula

    PubMed Central

    Van Ende, Charlotte; Wilmes, Dunja; Lecouvet, Frédéric E.; Labriola, Laura; Cuvelier, René; Van Ingelgem, Grégory; Jadoul, Michel

    2016-01-01

    A few single cases of Mycobacterium chelonae skin infection have been reported in haemodialysis patients. We report three additional cases that share peculiar clinical characteristics, pointing to diagnostic clues. All three cases presented as erythematous nodules developing distally to a proximal arteriovenous fistula (AVF). This presentation was identical to that of two published cases. A survey of all Belgian haemodialysis units during the period 2007–11 yields an estimated incidence of ∼0.9/10 000 patient-years. Although the source of M. chelonae remains unclear, this specific clinical presentation should be added to the listing of potential complications of an AVF and should be recognized, as it is fully treatable if diagnosed by culture and tissue biopsy.

  17. The morphology of Oreopithecus bambolii pollical distal phalanx.

    PubMed

    Almécija, Sergio; Shrewsbury, Marvin; Rook, Lorenzo; Moyà-Solà, Salvador

    2014-04-01

    Oreopithecus bambolii is a Late Miocene ape from Italy, first described in the late 19th century. Its interpretation is still highly controversial, especially in reference to its hand proportions and thumb morphology. In this study, the authors provide detailed descriptions of the available Oreopithecus pollical distal phalanx (PDP) specimens, as well as bivariate and multivariate morphometric analyses in comparison with humans, extant apes, selected anthropoid monkeys, and available Miocene PDP specimens. The multivariate results reveal two opposite poles on the hominoid PDP shape spectrum: on one side, a mediolaterally broad and dorsopalmarly short human PDP, and on the other side, the narrow and "conical" PDP of chimpanzees and orangutans. The authors contend that Oreopithecus exhibits intermediate PDP proportions that are largely primitive for hominoids because it shares morphological similarities with Proconsul. Furthermore, Oreopithecus displays a mediolaterally wide tuft for a hominoid, as well as a palmarly elevated attachment for a long tendon of a flexor muscle that is associated at its proximal edge with a proximal fossa and at its distal edge with an ungual fossa. These nonmetrical traits have been associated in humans with their capability to oppose and contact the proximal pads of the thumb and fingers, that is, pad-to-pad precision grasping. These traits reinforce previous studies that indicate a human-like thumb-to-hand length ratio compatible with pad-to-pad precision grasping in Oreopithecus. Although specific hand use is still unresolved in Oreopithecus, the results suggest enhanced manipulative skills (unrelated to stone tool-making) in this taxon relative to other (extant or fossil) hominoids.

  18. Weak charge form factor and radius of 208Pb through parity violation in electron scattering

    DOE PAGES

    Horowitz, C. J.; Ahmed, Z.; Jen, C. -M.; Rakhman, A.; Souder, P. A.; Dalton, M. M.; Liyanage, N.; Paschke, K. D.; Saenboonruang, K.; Silwal, R.; et al

    2012-03-26

    We use distorted wave electron scattering calculations to extract the weak charge form factor FW(more » $$\\bar{q}$$), the weak charge radius RW, and the point neutron radius Rn, of 208Pb from the PREX parity violating asymmetry measurement. The form factor is the Fourier transform of the weak charge density at the average momentum transfer $$\\bar{q}$$ = 0.475 fm-1. We find FW($$\\bar{q}$$) = 0.204 ± 0.028(exp) ± 0.001(model). We use the Helm model to infer the weak radius from FW($$\\bar{q}$$). We find RW = 5.826 ± 0.181(exp) ± 0.027(model) fm. Here the exp error includes PREX statistical and systematic errors, while the model error describes the uncertainty in RW from uncertainties in the surface thickness σ of the weak charge density. The weak radius is larger than the charge radius, implying a 'weak charge skin' where the surface region is relatively enriched in weak charges compared to (electromagnetic) charges. We extract the point neutron radius Rn = 5.751 ± 0.175 (exp) ± 0.026(model) ± 0.005(strange) fm, from RW. Here there is only a very small error (strange) from possible strange quark contributions. We find Rn to be slightly smaller than RW because of the nucleon's size. As a result, we find a neutron skin thickness of Rn-Rp = 0.302 ± 0.175 (exp) ± 0.026 (model) ± 0.005 (strange) fm, where Rp is the point proton radius.« less

  19. Atomic radii for atoms with the 6s shell outermost: The effective atomic radius and the van der Waals radius from {sub 55}Cs to {sub 80}Hg

    SciTech Connect

    Tatewaki, Hiroshi; Hatano, Yasuyo; Noro, Takeshi; Yamamoto, Shigeyoshi

    2015-06-15

    We consider, for atoms from {sub 55}Cs to {sub 80}Hg, the effective atomic radius (r{sub ear}), which is defined as the distance from the nucleus at which the magnitude of the electric field is equal to that in He at one half of the equilibrium bond length of He{sub 2}. The values of r{sub ear} are about 50% larger than the mean radius of the outermost occupied orbital of 6s, . The value of r{sub ear} decreases from {sub 55}Cs to {sub 56}Ba and undergoes increases and decreases with rising nuclear charge from {sub 57}La to {sub 70}Y b. In fact r{sub ear} is understood as comprising two interlaced sequences; one consists of {sub 57}La, {sub 58}Ce, and {sub 64}Gd, which have electronic configuration (4f{sup n−1})(5d{sup 1})(6s{sup 2}), and the remaining atoms have configuration (4f{sup n})(6s{sup 2}). The sphere defined by r{sub ear} contains 85%–90% of the 6s electrons. From {sub 71}Lu to {sub 80}Hg the radius r{sub ear} also involves two sequences, corresponding to the two configurations 5d{sup n+1}6s{sup 1} and 5d{sup n}6s{sup 2}. The radius r{sub ear} according to the present methodology is considerably larger than r{sub vdW} obtained by other investigators, some of who have found values of r{sub vdW} close to .

  20. Exclusion of Dlx5/6 expression from the distal-most mandibular arches enables BMP-mediated specification of the distal cap.

    PubMed

    Vincentz, Joshua W; Casasnovas, Jose J; Barnes, Ralston M; Que, Jianwen; Clouthier, David E; Wang, Jun; Firulli, Anthony B

    2016-07-01

    Cranial neural crest cells (crNCCs) migrate from the neural tube to the pharyngeal arches (PAs) of the developing embryo and, subsequently, differentiate into bone and connective tissue to form the mandible. Within the PAs, crNCCs respond to local signaling cues to partition into the proximo-distally oriented subdomains that convey positional information to these developing tissues. Here, we show that the distal-most of these subdomains, the distal cap, is marked by expression of the transcription factor Hand1 (H1) and gives rise to the ectomesenchymal derivatives of the lower incisors. We uncover a H1 enhancer sufficient to drive reporter gene expression within the crNCCs of the distal cap. We show that bone morphogenic protein (BMP) signaling and the transcription factor HAND2 (H2) synergistically regulate H1 distal cap expression. Furthermore, the homeodomain proteins distal-less homeobox 5 (DLX5) and DLX6 reciprocally inhibit BMP/H2-mediated H1 enhancer regulation. These findings provide insights into how multiple signaling pathways direct transcriptional outcomes that pattern the developing jaw.