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Sample records for joint surface injury

  1. Registration of knee joint surfaces for the in vivo study of joint injuries based on magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Cheng, Rita W. T.; Habib, Ayman F.; Frayne, Richard; Ronsky, Janet L.

    2006-03-01

    In-vivo quantitative assessments of joint conditions and health status can help to increase understanding of the pathology of osteoarthritis, a degenerative joint disease that affects a large population each year. Magnetic resonance imaging (MRI) provides a non-invasive and accurate means to assess and monitor joint properties, and has become widely used for diagnosis and biomechanics studies. Quantitative analyses and comparisons of MR datasets require accurate alignment of anatomical structures, thus image registration becomes a necessary procedure for these applications. This research focuses on developing a registration technique for MR knee joint surfaces to allow quantitative study of joint injuries and health status. It introduces a novel idea of translating techniques originally developed for geographic data in the field of photogrammetry and remote sensing to register 3D MR data. The proposed algorithm works with surfaces that are represented by randomly distributed points with no requirement of known correspondences. The algorithm performs matching locally by identifying corresponding surface elements, and solves for the transformation parameters relating the surfaces by minimizing normal distances between them. This technique was used in three applications to: 1) register temporal MR data to verify the feasibility of the algorithm to help monitor diseases, 2) quantify patellar movement with respect to the femur based on the transformation parameters, and 3) quantify changes in contact area locations between the patellar and femoral cartilage at different knee flexion angles. The results indicate accurate registration and the proposed algorithm can be applied for in-vivo study of joint injuries with MRI.

  2. Distal radioulnar joint injuries

    PubMed Central

    Thomas, Binu P; Sreekanth, Raveendran

    2012-01-01

    Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint, forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments. The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis. PMID:23162140

  3. Acromioclavicular and sternoclavicular joint injuries.

    PubMed

    Macdonald, Peter B; Lapointe, Pierre

    2008-10-01

    Acromioclavicular (AC) joint injuries are a frequent diagnosis following an acute shoulder injury. The literature on AC joint dislocation is extensive, reflecting the intense debate surrounding the topic. The choice of treatment is influenced by factors including the type of injury, the patient's occupation, the patient's past medical history, the acuity of the injury, and patient expectations. Sternoclavicular (SC) joint dislocation is an uncommon injury. The treatment of acute anterior SC joint dislocations is controversial. It is difficult to study with a well-designed prospective study because of the low frequency of this injury. Posterior dislocations are much less common than anterior dislocations. Posterior dislocations, however, are more serious; they are associated with significant complications and require prompt attention.

  4. [Injuries of the elbow joint].

    PubMed

    Lill, H; Voigt, C

    2004-10-01

    Injuries of the elbow joint increase along with increased athletic activity and life expectancy. Knowledge of anatomy and biomechanics is important for understanding injury patterns, specific diagnosis, and therapy. Here we classify the most frequent elbow injuries such as dislocation, ligamentous instability, and fracture of the radial head, processus coronoideus, olecranon, and distal humerus based on joint anatomy, biomechanics, clinical examination, and imaging. Specific therapies are described.

  5. Management of acromioclavicular joint injuries.

    PubMed

    Li, Xinning; Ma, Richard; Bedi, Asheesh; Dines, David M; Altchek, David W; Dines, Joshua S

    2014-01-01

    Acromioclavicular joint injuries are among the most common shoulder girdle injuries in athletes and most commonly result from a direct force to the acromion with the arm in an adducted position. Acromioclavicular joint injuries often present with associated injuries to the glenohumeral joint, including an increased incidence of superior labrum anterior posterior (SLAP) tears that may warrant further evaluation and treatment. Anteroposterior stability of the acromioclavicular joint is conferred by the capsule and acromioclavicular ligaments, of which the posterior and superior ligaments are the strongest. Superior-inferior stability is maintained by the coracoclavicular (conoid and trapezoid) ligaments. Type-I or type-II acromioclavicular joint injuries have been treated with sling immobilization, early shoulder motion, and physical therapy, with favorable outcomes. Return to activity can occur when normal shoulder motion and strength are obtained and the shoulder is asymptomatic as compared with the contralateral normal extremity. The management of type-III injuries remains controversial and is individualized. While a return to the previous level of functional activity with nonsurgical treatment has been documented in a number of case series, surgical reduction and coracoclavicular ligament reconstruction has been associated with a favorable outcome and can be considered in patients who place high functional demands on their shoulders or in athletes who participate in overhead sports. Surgical management is indicated for high-grade (≥type IV) acromioclavicular joint injuries to achieve anatomic reduction of the acromioclavicular joint, reconstruction of the coracoclavicular ligaments, and repair of the deltotrapezial fascia. Outcomes after surgical reconstruction of the coracoclavicular ligaments have been satisfactory with regard to achieving pain relief and return to functional activities, but further improvements in the biomechanical strength of these

  6. Computationally efficient magnetic resonance imaging based surface contact modeling as a tool to evaluate joint injuries and outcomes of surgical interventions compared to finite element modeling.

    PubMed

    Johnson, Joshua E; Lee, Phil; McIff, Terence E; Toby, E Bruce; Fischer, Kenneth J

    2014-04-01

    Joint injuries and the resulting posttraumatic osteoarthritis (OA) are a significant problem. There is still a need for tools to evaluate joint injuries, their effect on joint mechanics, and the relationship between altered mechanics and OA. Better understanding of injuries and their relationship to OA may aid in the development or refinement of treatment methods. This may be partially achieved by monitoring changes in joint mechanics that are a direct consequence of injury. Techniques such as image-based finite element modeling can provide in vivo joint mechanics data but can also be laborious and computationally expensive. Alternate modeling techniques that can provide similar results in a computationally efficient manner are an attractive prospect. It is likely possible to estimate risk of OA due to injury from surface contact mechanics data alone. The objective of this study was to compare joint contact mechanics from image-based surface contact modeling (SCM) and finite element modeling (FEM) in normal, injured (scapholunate ligament tear), and surgically repaired radiocarpal joints. Since FEM is accepted as the gold standard to evaluate joint contact stresses, our assumption was that results obtained using this method would accurately represent the true value. Magnetic resonance images (MRI) of the normal, injured, and postoperative wrists of three subjects were acquired when relaxed and during functional grasp. Surface and volumetric models of the radiolunate and radioscaphoid articulations were constructed from the relaxed images for SCM and FEM analyses, respectively. Kinematic boundary conditions were acquired from image registration between the relaxed and grasp images. For the SCM technique, a linear contact relationship was used to estimate contact outcomes based on interactions of the rigid articular surfaces in contact. For FEM, a pressure-overclosure relationship was used to estimate outcomes based on deformable body contact interactions. The SCM

  7. Osteoligamentous injuries of the medial ankle joint.

    PubMed

    Lötscher, P; Lang, T H; Zwicky, L; Hintermann, B; Knupp, M

    2015-12-01

    Injuries of the ankle joint have a high incidence in daily life and sports, thus, playing an important socioeconomic role. Therefore, proper diagnosis and adequate treatment are mandatory. While most of the ligament injuries around the ankle joint are treated conservatively, great controversy exists on how to treat deltoid ligament injuries in ankle fractures. Missed injuries and inadequate treatment of the medial ankle lead to inferior outcome with instability, progressive deformity, and ankle joint osteoarthritis.

  8. Joint and long-bone gunshot injuries.

    PubMed

    Dougherty, Paul J; Vaidya, Rahul; Silverton, Craig D; Bartlett, Craig S; Najibi, Soheil

    2010-01-01

    Gunshot wounds remain a major clinical problem, with the number of nonfatal gunshot wounds reported as 60,000 to 80,000 per year in the United States. Bone or joint injuries comprise a major portion of gunshot wound injuries. It is paramount for orthopaedic surgeons to be thorough in their treatment of patients with these injuries. Intra-articular injuries remain a source of significant clinical morbidity because of joint stiffness, arthritis, and the risk of infection. Treatment of long-bone fractures is a challenging clinical problem, and further studies are needed to investigate modern treatment methods. Lead toxicity is a potential risk for patients with gunshot injuries, particular for those with joint injuries. The clinician's recognition of the signs and symptoms of lead toxicity is important to achieve the best care for these patients.

  9. Temporomandibular joint dysfunction following shotgun injury.

    PubMed

    Taglialatela Scafati, C; Taglialatela Scafati, S; Gargiulo, M; Cassese, M; Parascandolo, S

    2008-04-01

    Shotgun injuries to the maxillofacial region may have minor or, more often, devastating consequences. The most important factor in determining the extent of injury is the distance of the victim from the muzzle of the gun: usually, the longer the distance, the less severe the damage. Here is reported a case of shotgun injury sustained from a distance of approximately 10 m in which the deeper penetration of a single lead pellet led to significant involvement of the temporomandibular joint.

  10. Management of chronic unstable acromioclavicular joint injuries.

    PubMed

    Cisneros, Luis Natera; Reiriz, Juan Sarasquete

    2017-03-08

    The acromioclavicular joint represents the link between the clavicle and the scapula, which is responsible for the synchronized dynamic of the shoulder girdle. Chronic acromioclavicular joint instability involves changes in the orientation of the scapula, which provokes cinematic alterations that might result in chronic pain. Several surgical strategies for the management of patients with chronic and symptomatic acromioclavicular joint instability have been described. The range of possibilities includes anatomical and non-anatomical techniques, open and arthroscopy-assisted procedures, and biological and synthetic grafts. Surgical management of chronic acromioclavicular joint instability should involve the reconstruction of the torn ligaments because it is accepted that from three weeks after the injury, these structures may lack healing potential. Here, we provide a review of the literature regarding the management of chronic acromioclavicular joint instability. Expert opinion, Level V.

  11. [Chronic sports injuries of the knee joint].

    PubMed

    Mannil, M; Andreisek, G; Weishaupt, D; Fischer, M A

    2016-05-01

    Chronic sports injuries of the knee joint are common and mainly caused by repetitive (micro) trauma and exertion. Chronic insertion tendinopathies and avulsion fractures and symptoms related to entrapment, friction and impingement can be pathophysiologically distinguished in athletes. In this review, we depict the characteristic magnetic resonance imaging (MRI) findings of the most commonly occurring pathologies.

  12. Management of acute unstable acromioclavicular joint injuries.

    PubMed

    Cisneros, Luis Natera; Reiriz, Juan Sarasquete

    2016-12-01

    Surgical management of acute unstable acromioclavicular joint injuries should be focused on realigning the torn ends of the ligaments to allow for healing potential. The most widely utilized treatment methods incorporate the use of metal hardware, which can alter the biomechanics of the acromioclavicular joint. This leads to a second surgical procedure for hardware removal once the ligaments have healed. Patients with unstable acromioclavicular joint injuries managed with arthroscopy-assisted procedures have shown good and excellent clinical outcomes, without the need for a second operation. These procedures incorporate a coracoclavicular suspension device aimed to function as an internal brace, narrowing the coracoclavicular space thus allowing for healing of the torn coracoclavicular ligaments. The lesser morbidity of a minimally invasive approach and the possibility to diagnose and treat concomitant intraarticular injuries; no obligatory implant removal, and the possibility of having a straight visualization of the inferior aspect of the base of the coracoid (convenient when placing coracoclavicular fixation systems) are the main advantages of the arthroscopic approach over classic open procedures. This article consists on a narrative review of the literature in regard to the management of acute acromioclavicular joint instability.

  13. Acute injuries of the distal radioulnar joint.

    PubMed

    Nicolaidis, S C; Hildreth, D H; Lichtman, D M

    2000-08-01

    Distal radioulnar joint injuries can occur in isolation or in association with distal radius fractures, Galeazzi fractures, Essex-Lopresti injuries, and both-bone forearm fractures. The authors have classified DRUJ/TFCC injuries into stable, partially unstable (subluxation), and unstable (dislocation) patterns based on the injured structures and clinical findings. Clinical findings and plain radiographs are usually sufficient to diagnose the lesion, but axial CT scans are pathognomonic. Diagnostic arthroscopy is the next test of choice to visualize stable and partially unstable lesions. Stable injuries of the DRUJ/TFCC unresponsive to conservative measures require arthroscopic debridement of the TFCC tear, along with ulnar shortening if there is ulnar-positive variance. Partially unstable injuries, on the other hand, are treated with direct arthroscopic or open repair of the TFCC tear, once again, along with ulnar shortening if ulnar-positive variance is present. Unstable injuries include simple and complex DRUJ dislocations. A simple DRUJ dislocation is easily reducible but may be stable or unstable. In complex dislocation, reduction is not possible because there is soft tissue interposition or a significant tear. After the associated injury is dealt with, treatment for complex injuries requires exploration of the DRUJ, extraction of the interposed tissue, repair of the soft tissues, and open reduction and internal fixation of the ulnar styloid fracture (if present and displaced). The early recognition and appropriate treatment of an acute DRUJ injury are critical to avoid progression to a chronic DRUJ disorder, the treatment of which is much more difficult and much less satisfying.

  14. Acromioclavicular joint injuries in the National Football League: epidemiology and management.

    PubMed

    Lynch, T Sean; Saltzman, Matthew D; Ghodasra, Jason H; Bilimoria, Karl Y; Bowen, Mark K; Nuber, Gordon W

    2013-12-01

    Previous studies investigating acromioclavicular (AC) joint injuries in professional American football players have only been reported on quarterbacks during the 1980s and 1990s. These injuries have not been evaluated across all position players in the National Football League (NFL). The purpose of this study was 4-fold: (1) to determine the incidence of AC joint injuries among all NFL position players; (2) to investigate whether player position, competition setting, type of play, and playing surface put an athlete at an increased risk for this type of injury; (3) to determine the incidence of operative and nonoperative management of these injuries; and (4) to compare the time missed for injuries treated nonoperatively to the time missed for injuries requiring surgical intervention. Descriptive epidemiological study. All documented injuries of the AC joint were retrospectively analyzed using the NFL Injury Surveillance System (NFLISS) over a 12-season period from 2000 through 2011. The data were analyzed by the anatomic location, player position, field conditions, type of play, requirement of surgical management, days missed per injury, and injury incidence. Over 12 NFL seasons, there were a total of 2486 shoulder injuries, with 727 (29.2%) of these injuries involving the AC joint. The overall rate of AC joint injuries in these athletes was 26.1 injuries per 10,000 athlete exposures, with the majority of these injuries occurring during game activity on natural grass surfaces (incidence density ratio, 0.79) and most often during passing plays. These injuries occurred most frequently in defensive backs, wide receivers, and special teams players; however, the incidence of these injuries was greatest in quarterbacks (20.9 injuries per 100 players), followed by special teams players (20.7/100) and wide receivers (16.5/100). Overall, these athletes lost a mean of 9.8 days per injury, with quarterbacks losing the most time to injury (mean, 17.3 days). The majority of

  15. Biomarkers for equine joint injury and osteoarthritis.

    PubMed

    McIlwraith, C Wayne; Kawcak, Christopher E; Frisbie, David D; Little, Christopher B; Clegg, Peter D; Peffers, Mandy J; Karsdal, Morten A; Ekman, Stina; Laverty, Sheila; Slayden, Richard A; Sandell, Linda J; Lohmander, L Stefan; Kraus, Virginia B

    2017-09-16

    We report the results of a symposium aimed at identifying validated biomarkers that can be used to complement clinical observations for diagnosis and prognosis of joint injury leading to equine osteoarthritis (OA). Biomarkers might also predict pre-fracture change that could lead to catastrophic bone failure in equine athletes. The workshop was attended by leading scientists in the fields of equine and human musculoskeletal biomarkers to enable cross-disciplinary exchange and improve knowledge in both. Detailed proceedings with strategic planning was written, added to, edited and referenced to develop this manuscript. The most recent information from work in equine and human osteoarthritic biomarkers was accumulated, including the use of personalized healthcare to stratify OA phenotypes, transcriptome analysis of anterior cruciate ligament (ACL) and meniscal injuries in the human knee. The spectrum of "wet" biomarker assays that are antibody based that have achieved usefulness in both humans and horses, imaging biomarkers and the role they can play in equine and human OA was discussed. Prediction of musculoskeletal injury in the horse remains a challenge, and the potential usefulness of spectroscopy, metabolomics, proteomics, and development of biobanks to classify biomarkers in different stages of equine and human OA were reviewed. The participants concluded that new information and studies in equine musculoskeletal biomarkers have potential translational value for humans and vice versa. OA is equally important in humans and horses, and the welfare issues associated with catastrophic musculoskeletal injury in horses add further emphasis to the need for good validated biomarkers in the horse. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  16. Injury Criteria for Dynamic Hyperextension of the Female Elbow Joint

    DTIC Science & Technology

    2006-11-01

    1 INJURY CRITERIA FOR DYNAMIC HYPEREXTENSION OF THE FEMALE ELBOW JOINT Stefan M. Duma*, Gail A. Hansen, Eric A. Kennedy, Joel D. Stitzel...Laboratory Fort Rucker, AL 36362 ABSTRACT This paper describes an analysis to develop dynamic hyperextension injury criteria for the female elbow ...joint. Dynamic hyperextension tests were performed on 24 female cadaver elbow joints. The energy source was a drop tower utilizing a three-point

  17. [Vascular injuries in joint replacement surgery].

    PubMed

    Novotný, K; Pádr, R; Landor, I; Sosna, A

    2011-01-01

    Iatrogenic injuries to blood vessels in joint replacement surgery are rare events that occur as few per thousand. However, their sequelae are serious. The patient may either bleed to death, because vascular injury is not obvious and therefore difficult to diagnose, or lose the limb due to ischaemia. The highest risk of vascular injury is associated with repeat surgery and loosening of the acetabular component. We distinguish sharp and blunt force injuries. The former are caused by implants, sharp instruments, bone fragments or bone cement debris. The latter arise from stretching over a part of implanted material. Bleeding can be inapparent or apparent. Inapparent bleeding is difficult to diagnose and is recognized from the dynamics of blood losses. Haemodynamic instability or, in a worse case, even hypovolaemic shock may be the only signs of bleeding. Occlusion of an artery is manifested by limb ischaemia. The seriousness and progression of ischaemia depends on the rate of arterial occlusion, potential pathways for collateral circulation and the degree of atherosclerotic vascular disease. The patient with conduction anaesthesia does not feel pain and therefore the diagnosis must primarily be based on arterial pulsation in the limb and its skin colour. A pseudoaneurysm can develop due to a partially weakened vascular wall and its rupture is a life-threatening complication. Its presence is recognized as a pulsating mass in the groin. An arterio- venous fistula which arises from traumatic communication between the two vessels may lead to cardiac failure. The diagnosis is based on examination by sonography and digital subtraction angiography. The results of CT angiography and MR angiography are difficult to evaluate because of the presence of metal implants. In apparent bleeding it is sometimes difficult to locate the source. It is recommended to perform digital compression and gain access to the vessels from the extraperitoneal approach. When an expanding haematoma or

  18. Ulnopalmar dislocation of the fifth carpometacarpal joint. A rare injury.

    PubMed

    Fischer, J W; Waseem, M; Gambhir, A; Creedon, R J

    2002-04-01

    Volar dislocation of the carpometacarpal joint of the little finger is an uncommon injury. It is subdivided in ulnopalmar and radiopalmar dislocations. The injury can easily be missed on standard x-rays. Closed reduction and K-wire fixation has commonly been used in the treatment, although closed reduction and casting has been reported. Only 10 cases of an ulnopalmar dislocation were published previously. We report a case of a simultaneous dislocation of the 4th metacarpophalangeal joint and an ulnopalmar dislocation of the 5th carpometacarpal joint. The combination of these injuries has not been reported yet. We review the available literature and discuss the methods of treatment.

  19. Generalized Models for Rock Joint Surface Shapes

    PubMed Central

    Du, Shigui; Hu, Yunjin; Hu, Xiaofei

    2014-01-01

    Generalized models of joint surface shapes are the foundation for mechanism studies on the mechanical effects of rock joint surface shapes. Based on extensive field investigations of rock joint surface shapes, generalized models for three level shapes named macroscopic outline, surface undulating shape, and microcosmic roughness were established through statistical analyses of 20,078 rock joint surface profiles. The relative amplitude of profile curves was used as a borderline for the division of different level shapes. The study results show that the macroscopic outline has three basic features such as planar, arc-shaped, and stepped; the surface undulating shape has three basic features such as planar, undulating, and stepped; and the microcosmic roughness has two basic features such as smooth and rough. PMID:25152901

  20. Heterotopic Vascularized Joint Transfer in Mutilating Hand Injuries.

    PubMed

    Chang, Nai-Jen; Chang, Johnny T; Hsu, Chung-Chen; Lin, Cheng-Hung; Lin, Chih-Hung; Lin, Yu-Te

    2016-03-01

    In cases of mutilating hand injuries, the primary goal is recovery of prehensile function. This is particularly true in the case of joints, which are extremely difficult to replace or reconstruct adequately when damaged. Heterotopic vascularized joint transfer is indicated when salvageable joints are available for transfer to a more functionally optimal position on the hand. Seven cases of mutilating hand injuries treated with heterotopic vascularized joint transfers from 2003 to 2012 were retrospectively identified. All patients sustained severe metacarpophalangeal joint (MPJ) or proximal interphalangeal joint (PIPJ) damage that threatened recovery of optimal hand function. All patients were men, with an average age of 34.7 years. Operative, perioperative, and postoperative details including final active range of motion were collected and analyzed. Seven joints were taken from nonsalvageable amputated digits: 4 from the amputated parts, and 3 from the proximal stumps. Five joints were transferred as free flaps requiring microvascular anastomosis, and 2 were transferred on neurovascular pedicles. One joint was lost due to vasospasm. Average active range of motion was 68.3° for homojoint transfers (MPJ to MPJ, PIPJ to PIPJ), and 35° for heterojoint transfers. All but 1 patient were able to achieve tripod pinch; the remaining patient achieved only side-to-side pinch. Heterotopic vascularized joint transfer is a useful technique to consider in cases of mutilating hand injuries. Improved recovery of prehensile function can be achieved with thoughtful design and execution, followed by proper patient education and rehabilitation.

  1. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2013-10-01

    future registries of acute joint injuries. 2. KEYWORDS: Post-traumatic arthritis, post-traumatic osteoarthritis , articular fracture, joint injury...PTA and MRL/MpJ mice that are protected from PTA. Serum and synovial 4 "Assessment of Biomarkers Associated with Joint Injury and Subsequent Post... Joint Injury and Subsequent Post- Traumatic Arthritis PRINCIPAL INVESTIGATOR: Virginia B. Kraus CONTRACTING ORGANIZATION: Duke

  2. Inflammation in Joint Injury and Post-Traumatic Osteoarthritis

    PubMed Central

    Lieberthal, Jason; Sambamurthy, Nisha; Scanzello, Carla R.

    2015-01-01

    Inflammation is a variable feature of osteoarthritis (OA), associated with joint symptoms and progression of disease. Signs of inflammation can be observed in joint fluids and tissues from patients with joint injuries at risk for development of post-traumatic osteoarthritis (PTOA). Furthermore, inflammatory mechanisms are hypothesized to contribute to the risk of OA development and progression after injury. Animal models of PTOA have been instrumental in understanding factors and mechanisms involved in chronic progressive cartilage degradation observed after a predisposing injury. Specific aspects of inflammation observed in humans, including cytokine and chemokine production, synovial reaction, cellular infiltration and inflammatory pathway activation, are also observed in models of PTOA. Many of these models are now being utilized to understand the impact of post-injury inflammatory response on PTOA development and progression, including risk of progressive cartilage degeneration and development of chronic symptoms post-injury. As evidenced from these models, a vigorous inflammatory response occurs very early after joint injury but is then sustained at a lower level at the later phases. This early inflammatory response contributes to the development of PTOA features including cartilage erosion and is potentially modifiable, but specific mediators may also play a role in tissue repair. Although the optimal approach and timing of anti-inflammatory interventions after joint injury are yet to be determined, this body of work should provide hope for the future of disease modification tin PTOA. PMID:26521728

  3. Joint Global War on Terror (GWOT) Vascular Injury Study 2

    DTIC Science & Technology

    2017-02-01

    and clinical management information from the Joint Theater Trauma Registry (JTTR) to authentic patient-based outcomes years following injury. In this...outcomes following extremity vascular injury in the wars in Afghanistan and Iraq. This study proposes to link acute injury and clinical management... reasons for change Nothing to Report Actual or anticipated problems or delays and actions or plans to resolve them - Technology support staffing

  4. Decision making: operative versus nonoperative treatment of acromioclavicular joint injuries.

    PubMed

    Bradley, James P; Elkousy, Hussein

    2003-04-01

    The classification system devised by Allman and Tossy, and revised by Rockwood, defines the extent of injury to the AC joint and helps to guide management of AC joint injuries [1,4,6]. In general, type I and II injuries may be treated nonoperatively with a sling, mainly for comfort, for a short period of time. Once this is removed, strength and motion are regained with rehabilitation. Patients typically have manageable long-term symptoms without any intervention, but some may require a steroid injection or distal clavicle excision for chronic pain from degenerative changes at the AC joint due to the injury. On the other end of the spectrum, type IV, V, and VI injuries nearly always require operative intervention. The surgical procedures for these injuries are performed in the acute phase if possible to minimize symptoms and maximize long-term function. Type III injuries are the center of the controversy for management of AC joint injuries. No perfect study exists which demonstrates clear superiority of surgical or nonsurgical treatment. Most of the studies in the literature support nonoperative treatment for most patients, however. Yet, other factors must be considered, including the patient's occupation and physical demands as well as the age of the injury. Overhead athletes and manual laborers place high demands on their shoulders, prompting some authors to consider acute surgical management for these patients. We, on the other hand, agree with the current consensus opinion that all type III injuries should initially be treated conservatively, regardless of occupation. The only advantage to operative intervention consistently borne out in the literature is an increased probability of anatomic reduction. There is no correlation between reduction and improvement in pain, strength, or motion, however. These patients usually are able to return to full sport with no deficits if rehabilitation is emphasized. For those patients who fail conservative management, a

  5. Carpal joint injuries in cats - an epidemiological study.

    PubMed

    Nakladal, B; vom Hagen, F; Brunnberg, M; Gross, M; Nietz, H; Brunnberg, L

    2013-01-01

    Injuries of the carpal joint are rare in cats. The most common cause is a fall from a height, known as 'high-rise syndrome'. So far, only limited data about carpal joint injuries (CJI) in cats are available. The aim of this study was to investigate the epidemiology, aetiology, location, and type of CJI in cats. Case records of cats diagnosed with CJI between 1998 and 2010 were retrospectively analysed. Data concerning signalment, history and type of CJI, accompanying systemic injuries and further orthopaedic injuries were collected. During the study period, 73 cats were diagnosed with CJI (87 injured carpal joints) and the prevalence in our hospital population was 0.26% (73 out of  28,482). Cats with CJI were more likely to be presented in the period from April-October (85%, p = 0.003) compared with the rest of the year. Carpal joint injuries were caused by a fall from a height in 72.6% of the cases. Of all carpal joints, the antebrachiocarpal joint was predominantly injured (50.6%, p = 0.001) and this was commonly caused by a fall from the fourth floor or higher (p = 0.002). The carpometacarpal joint was predominantly affected by a fall from heights up to the third floor (p = 0.004). The data of this study confirm previous data with respect to time of occurrence and cause of injury. Of note, the height of the fall appears to influence the location of the injury within the carpus of cats.

  6. Posterior sternoclavicular joint injuries in skeletally immature patients.

    PubMed

    Lee, Jared T; Nasreddine, Adam Y; Black, Eric M; Bae, Donald S; Kocher, Mininder S

    2014-06-01

    Posterior injuries to the sternoclavicular (SC) joint are uncommon. In the skeletally immature (SI) population, these injuries have been described as either dislocations of the SC joint or fractures of the medial clavicular physis. The current literature and standardized test questions state that a posterior SC injury, in a SI patient, is more likely a physeal fracture than a SC joint dislocation. However, this injury characterization is based on case reports or small case series. The purpose of this study is to characterize posterior SC injuries in SI patients in terms of the prevalence of dislocation versus medial clavicle physeal fracture. A retrospective review was performed of 48 SI patients treated for posterior SC joint injuries over a 20-year period with a mean age of 15.4 years (range, 13 to 18 y). Forty patients underwent open reduction and internal fixation as their definitive treatment and 8 patients were treated exclusively with closed reduction. Patients treated operatively were utilized in determining the prevalence of SC joint dislocation versus physeal fracture. All patients treated operatively underwent primary repair without reconstruction. Twenty (50%), of the 40 patients treated operatively had a true SC joint dislocation and 20 patients (50%) had a medial clavicle physeal fracture. Twenty-two (46%) of the 48 total patients had an attempted closed reduction of which only 8 (36%) were successful. Among the 14 unsuccessful closed reductions, 12 (86%) were true dislocations (P<0.001). All successful closed reductions occurred in patients within 24 hours from injury. Eleven of the 48 (23%) patients' injuries were missed on initial presentation. Posterior SC joint dislocation and medial clavicular physeal fracture both occur with roughly equivalent prevalence in patients with an open medial physis. An attempted closed reduction may be more successful if performed within 24 hours after injury. Patients who fail attempts at closed reduction are more

  7. [Lateral ligament injuries of the ankle joint].

    PubMed

    Walther, M; Kriegelstein, S; Altenberger, S; Volkering, C; Röser, A; Wölfel, R

    2013-09-01

    Lateral ligament injuries are the most common sports injury and have a high incidence even in non-sportive activities. Although lateral ligament injuries are very common there is still a controversial debate on the best management. The diagnosis is based on clinical examination and X-ray images help to rule out fractures. Further imaging, especially magnetic resonance imaging (MRI) is used to diagnose associated injuries. According to the recommendations of the various scientific societies the primary therapy of lateral ligament injuries is conservative. Chronic ankle instability develops in 10-20 % of patients and the instability can be a result of sensomotoric deficits or insufficient healing of the lateral ligament complex. If the patient does not respond to an intensive rehabilitation program an operative reconstruction of the lateral ligaments has to be considered. Most of the procedures currently performed are anatomical reconstructions due to better long-term results compared to tenodesis procedures.

  8. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2013-10-01

    future registries of acute joint injuries. 2. KEYWORDS: Post-traumatic arthritis, post-traumatic osteoarthritis , articular fracture, joint ...develop PTA and MRL/MpJ mice that are protected from PTA. Serum and synovial 4 "Assessment of Biomarkers Associated with Joint Injury and Subsequent Post... Joint Injury and Subsequent Post- Traumatic Arthritis PRINCIPAL INVESTIGATOR: Farshid Guilak CONTRACTING ORGANIZATION: Duke

  9. Correlations Between General Joint Hypermobility and Joint Hypermobility Syndrome and Injury in Contemporary Dance Students.

    PubMed

    Ruemper, Alia; Watkins, Katherine

    2012-12-01

    The first objective of this study was to ascertain the prevalence of general joint hypermobility (GJH) and joint hypermobility syndrome (JHS) in BA Dance Theatre 1st and 3rd year students at a contemporary dance conservatory. The second objective was to determine the statistical correlation between GJH, JHS, and injury in this population. A total of 85 (female, N = 78; male, N = 7) contemporary dance students participated in the study. The Beighton score (with a forward flexion test modification) was used to determine GJH, and the Brighton criteria were used to verify JHS. Participants completed a self-reported injury questionnaire that included type of injury (physical complaint, medical diagnosis, or time-loss) and injury frequency. Statistical analysis (Pearson correlation) was used to correlate GJH, JHS, and frequency-of-injury scores. Overall, 69% of the students were found to have GJH, and 33% had JHS. A statistical correlation of r = + 0.331 (p < 0.01) was found between JHS and injury. No significant correlation was found between GJH and injury. This is the first study to look at these correlations in contemporary dance students and suggests that screening programs should include the Brighton criteria to identify JHS in these dancers. Subsequent injury tracking and injury prevention programs would then provide data for further research in this area.

  10. Acromioclavicular joint dislocation with associated brachial plexus injury

    PubMed Central

    Gallagher, Charles Alexander; Blakeney, William; Zellweger, René

    2014-01-01

    We present the case of a 32-year-old female who sustained a left acromioclavicular (AC) joint type V injury and brachial plexus injury. The patient's AC joint injury was identified 6 days after she was involved in a motorbike accident where she sustained multiple other injuries. She required operative fixation of the AC joint using a locking compression medial proximal tibial plate. At 3 months post operatively, the patient was found to have a subluxed left shoulder as a result of an axonal injury to the upper trunk of the brachial plexus. In addition, the tibial plate had cut out. The plate was subsequently removed. At 8 months the glenohumeral articulation had been restored and the patient had clinically regained significant shoulder function. After 15 months the patient was pain free and could complete all her activities of daily living without impediment. She returned to playing competitive pool after 24 months. PMID:24855076

  11. An Interesting Case of Gunshot Injury to the Temporomandibular Joint

    PubMed Central

    Pires, Mário Sergio Medeiros; Giongo, Caroline Comis; Antonello, Guilherme de Marco; Couto, Ricardo Torres do; Filho, Ruy de Oliveira Veras; Junior, Otacílio Luiz Chagas

    2014-01-01

    The head and face are relatively common sites of gunshot injury, and the temporomandibular joint is often affected. These wounds usually produce major deformity and functional impairment, particularly when the temporomandibular joint is affected or when structures such as the facial nerve are damaged. Complications may include mandibular displacement at maximum mouth opening and in protrusion, limited mouth opening, limited lateral movement of the jaw, anterior open bite, and, more rarely, temporomandibular ankylosis. Projectiles that strike the mandible usually cause comminuted fractures; maxillary wounds, in turn, are most commonly perforating. The present report describes a case of gunshot injury in which the projectile lodged within the mandibular fossa but did not cause any fractures. Oral and maxillofacial trauma surgeons must be aware of the different types of gunshot injury, as they produce distinct patterns of tissue destruction due to projectile trajectory and release of kinetic energy into surrounding tissue. PMID:25709756

  12. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2013-10-01

    may be useful in future registries of acute joint injuries. 2. KEYWORDS: Post-traumatic arthritis, post-traumatic osteoarthritis , articular...6 mice that develop PTA and MRL/MpJ mice that are protected from PTA. Serum and synovial 4 "Assessment of Biomarkers Associated with Joint Injury... Joint Injury and Subsequent Post- Traumatic Arthritis PRINCIPAL INVESTIGATOR: Steven A. Olson CONTRACTING ORGANIZATION: Duke

  13. Development of a Lubricant Therapy to Prevent Development of Osteoarthritis after Acute Injury of Synovial Joints

    DTIC Science & Technology

    2015-10-01

    changes in lubricant molecules and function of joint fluid post -injury in a rabbit model as well as early, mid, and late changes post -injury in human...determined. 15. SUBJECT TERMS Cartilage, Wear, Lubrication, Friction, Post -traumatic osteoarthritis, Injury, Blood, Synovial Fluid, Joint 16. SECURITY...synovial fluid after joint injury contributes to the development of post -traumatic OA and is due, in part, to the pathological accumulation of a

  14. Knee Joint Dysfunctions That Influence Gait in Cerebrovascular Injury

    PubMed Central

    Lucareli, Paulo Roberto Garcia; Greve, Julia Maria D’Andrea

    2008-01-01

    INTRODUCTION There is still no consensus among different specialists on the subject of kinematic variation during the hemiparetic gait, including the main changes that take place during the gait cycle and whether the gait velocity changes the patterns of joint mobility. One of the most frequently discussed joints is the knee. OBJECTIVES This study aims to evaluate the variables found in the angular kinematics of knee joint, and to describe the alterations found in the hemiparetic gait resulting from cerebrovascular injury. METHODS This study included 66 adult patients of both genders with a diagnosis of either right or left hemiparesis resulting from ischemic cerebrovascular injury. All the participants underwent three-dimensional gait evaluation, an the angular kinematics of the joint knee were selected for analysis. RESULTS The results were distributed into four groups formed based on the median of the gait speed and the side of hemiparesis. CONCLUSIONS The relevant clinical characteristics included the important mechanisms of loading response in the stance, knee hyperextension in single stance, and reduction of the peak flexion and movement amplitude of the knee in the swing phase. These mechanisms should be taken into account when choosing the best treatment. We believe that the findings presented here may aid in preventing the occurrence of the problems found, and also in identifying the origin of these problems. PMID:18719753

  15. Joint fluid antioxidants are decreased in osteoarthritic joints compared to joints with macroscopically intact cartilage and subacute injury.

    PubMed

    Regan, E A; Bowler, R P; Crapo, J D

    2008-04-01

    Excess reactive oxygen species and oxidative damage have been associated with the pathogenesis of osteoarthritis (OA). Extracellular superoxide dismutase (EC-SOD or SOD3) scavenges superoxide is the major catalytic antioxidant in joint fluid and is decreased in OA cartilage. We studied human joint fluid samples to test whether there is an association between OA and EC-SOD or other low molecular antioxidants in the joint fluid. Joint fluid samples were obtained from 28 subjects with severe OA undergoing arthrocentesis or knee joint replacement and compared to joint fluid from 12 subjects undergoing knee arthroscopy for chronic knee pain, meniscal tears or anterior cruciate ligament reconstruction. EC-SOD protein was assayed by enzyme-linked immunosorbent assay (ELISA). Ascorbate and urate were measured with high performance liquid chromatography (HPLC) and total nitrates by the Greiss reaction. Glutathione (GSH) and oxidized glutathione were measured using a colorimetric method. Interleukin-6 (IL-6) and transforming growth factor-beta (TGF-beta) were both measured with ELISA. Human joint fluid contains significant amounts of the extracellular, catalytic antioxidant EC-SOD. Joint fluid from OA subjects is characterized by significantly decreased EC-SOD levels and significant decreases in GSH, and ascorbate compared to the reference group of knee joints with pain or subacute injury but macroscopically intact cartilage. GSH and ascorbate show only an age effect with no effect from disease state on regression modeling. Urate is present in joint fluid but does not show a significant difference between groups. IL-6 and TGF-beta both show non-significant trends to increases in the arthritic subjects. There was no correlation of EC-SOD levels with IL-6 as a marker of inflammation in either the comparison group or the OA group. EC-SOD, the major scavenger of reactive oxygen species (ROS) in extracellular spaces and fluids, is decreased in late stage OA joint fluid compared

  16. [Surgical treatment of stiff metacarpophalangeal joint after hand injury].

    PubMed

    Rui, Yongjun; Shi, Haifeng; Mi, Jingyi; Chen, Guang; Wang, Jun; Qian, Jun

    2011-05-01

    To discuss the surgical procedures and curative effect of stiff 2-5 metacarpophalangeal (MP) joints after crash injury in hand. Between January 2006 and June 2009, 7 cases of stiff 2-5 MP joints were treated by releasing the stiff MP joints and reconstructing the function of lumbrical muscle in one stage. There were 6 males and 1 female with an average age of 32 years (range, 18-56 years). All injuries were caused by crash. Six cases suffered from multiple metacarpal fracture or complex dislocation of MP joint and 1 case suffered from complete amputation at level of middle palm of hand. The interval from initial wound healing to hospitalization was 3 to 15 months. Before operation, the X-ray films showed fracture healed and the results of nipping paper test were positive. All hands were treated with physical therapy for 1 month. After the plaster external fixation for 6 weeks, the physical therapy and function training were given. All wounds healed by first intention. The patients had no joint instability and extensor tendon side-slipping with normal finger function. Six patients were followed up from 6 months to 3 years. The extension and flexion of MP joint were 0 degree and 67-90 degrees, respectively. The average grip strength of injured dominant hand reached 86.70% of normal side and non-dominant hand reached 66.70% of normal side. The average injured dominant tip pinch strength reached 83.52% of normal side and non-dominant tip pinch strength reached 61.30% of normal side. Based on total active motion (TAM) system of Chinese Medical Association for Hand Surgery, the results were excellent in 4 cases, good in 1 case, and fair in 1 case; the excellent and good rate was 83.33%. In patients with stiff MP joint and lumbrical muscle defect, releasing stiff MP joint and reconstructing lumbrical function in one stage can recover the function of MP joint and achieve good outcome. Physical therapy plays an important role before operation.

  17. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2014-10-01

    Joint Injury and Subsequent Post- Traumatic Arthritis PRINCIPAL INVESTIGATOR: Steven A. Olson CONTRACTING ORGANIZATION: Duke...COVERED 30 Sep 2013 - 29 Sep 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Assessment of Biomarkers Associated with Joint Injury and Subsequent...the development of post-traumatic arthritis (PTA). PTA is a clinically important complication of joint injury with life-long effects for the

  18. Decreased Knee Joint Loading Associated With Early Knee Osteoarthritis After Anterior Cruciate Ligament Injury.

    PubMed

    Wellsandt, Elizabeth; Gardinier, Emily S; Manal, Kurt; Axe, Michael J; Buchanan, Thomas S; Snyder-Mackler, Lynn

    2016-01-01

    Anterior cruciate ligament (ACL) injury predisposes individuals to early-onset knee joint osteoarthritis (OA). Abnormal joint loading is apparent after ACL injury and reconstruction. The relationship between altered joint biomechanics and the development of knee OA is unknown. Altered knee joint kinetics and medial compartment contact forces initially after injury and reconstruction are associated with radiographic knee OA 5 years after reconstruction. Case-control study; Level of evidence, 3. Individuals with acute, unilateral ACL injury completed gait analysis before (baseline) and after (posttraining) preoperative rehabilitation and at 6 months, 1 year, and 2 years after reconstruction. Surface electromyographic and knee biomechanical data served as inputs to an electromyographically driven musculoskeletal model to estimate knee joint contact forces. Patients completed radiographic testing 5 years after reconstruction. Differences in knee joint kinetics and contact forces were compared between patients with and those without radiographic knee OA. Patients with OA walked with greater frontal plane interlimb differences than those without OA (nonOA) at baseline (peak knee adduction moment difference: 0.00 ± 0.08 N·m/kg·m [nonOA] vs -0.15 ± 0.09 N·m/kg·m [OA], P = .014; peak knee adduction moment impulse difference: -0.001 ± 0.032 N·m·s/kg·m [nonOA] vs -0.048 ± 0.031 N·m·s/kg·m [OA], P = .042). The involved limb knee adduction moment impulse of the group with osteoarthritis was also lower than that of the group without osteoarthritis at baseline (0.087 ± 0.023 N·m·s/kg·m [nonOA] vs 0.049 ± 0.018 N·m·s/kg·m [OA], P = .023). Significant group differences were absent at posttraining but reemerged 6 months after reconstruction (peak knee adduction moment difference: 0.02 ± 0.04 N·m/kg·m [nonOA] vs -0.06 ± 0.11 N·m/kg·m [OA], P = .043). In addition, the OA group walked with lower peak medial compartment contact forces of the involved limb

  19. Volar metacarpal phalangeal joint dislocation: a rare and often missed injury.

    PubMed

    Hargarten, S W; Hanel, D P

    1992-09-01

    Volar metacarpal phalangeal joint dislocations are rare injuries. We could find only eight cases reported, with none in the emergency medicine literature. We present a case report and describe the biomechanics and radiographic findings of this injury.

  20. Comparative study of the detection of joint injury in early-stage rheumatoid arthritis by magnetic resonance imaging of the wrist and finger joints and physical examination.

    PubMed

    Tamai, Mami; Kawakami, Atsushi; Iwamoto, Naoki; Kawashiri, Shin-Ya; Fujikawa, Keita; Aramaki, Toshiyuki; Kita, Junko; Okada, Akitomo; Koga, Tomohiro; Arima, Kazuhiko; Kamachi, Makoto; Yamasaki, Satoshi; Nakamura, Hideki; Ida, Hiroaki; Origuchi, Tomoki; Takao, Shoichiro; Aoyagi, Kiyoshi; Uetani, Masataka; Eguchi, Katsumi

    2011-03-01

    To verify whether magnetic resonance imaging (MRI)-proven joint injury is sensitive as compared with joint injury determined by physical examination. MRI of the wrist and finger joints of both hands was examined in 51 early-stage rheumatoid arthritis (RA) patients by both plain and gadolinium diethylenetriaminepentaacetic acid-enhanced MRI. Synovitis, bone edema, and bone erosion (the latter two included as bone lesions at the wrist joints); metacarpophalangeal joints; and proximal interphalangeal joints were considered as MRI-proven joint injury. Japan College of Rheumatology-certified rheumatologists had given a physical examination just before the MRI study. The presence of tender and/or swollen joints in the same fields as MRI was considered as joint injury on physical examination. The association of MRI-proven joint injury with physical examination-proven joint injury was examined. A total of 1,110 sites were available to be examined. MRI-proven joint injury was found in 521 sites, whereas the other 589 sites were normal. Physical examination-proven joint injury was found in 305 sites, which was significantly low as compared with MRI-proven joint injury (P = 1.1 × 10(-12) versus MRI). Joint injury on physical examination was not found in 81.5% of the sites where MRI findings were normal. Furthermore, an association of the severity of MRI-proven joint injury with that of joint injury on physical examination was clearly demonstrated (P = 1.6 × 10(-15), r(s) = 0.469). Our present data suggest that MRI is not only sensitive but accurately reflects the joint injury in patients with early-stage RA. Copyright © 2011 by the American College of Rheumatology.

  1. Sports injury, occupational physical activity, joint laxity, and meniscal damage.

    PubMed

    Baker, Paul; Coggon, David; Reading, Isabel; Barrett, David; McLaren, Magnus; Cooper, Cyrus

    2002-03-01

    To investigate the risk factors for meniscal damage, an important determinant of knee osteoarthritis. We studied 243 men and women aged 20-59 years in whom the diagnosis of a meniscal tear was confirmed for the first time at arthroscopy, over a 25 month period, in 2 British hospitals. Each case was compared with one or 2 community controls, matched by age and sex, who were registered with the same general practitioner. Information on exposure to risk factors was obtained by a structured questionnaire and physical examination. Meniscal tear was strongly associated with participation in sports during the 12 months preceding the onset of symptoms; the risk was particularly high for soccer (OR 3.7; 95% CI 2.1-6.6). Higher body mass index and occupational kneeling (OR 3.8; 95% CI 1.3-11.0) and squatting (OR 2.9; 95% CI 1.0-8.0) were associated with an increased risk of degenerative meniscal lesions, after adjustment for social class, joint laxity, and sports participation. Joint laxity was associated with degenerative meniscal lesions independently of occupational physical activity, sports, and obesity. Our results confirm the importance of sporting activities entailing knee torsion in acute meniscal tear. They also point to a role for occupational activity, adiposity, and joint laxity in the pathogenesis of degenerative meniscal lesions. Modifying these mechanical risk factors may serve to reduce the risk of meniscal injury and may also help to prevent later knee osteoarthritis.

  2. Improving Joint Function Using Photochemical Hydrogels for Articular Surface Repair

    DTIC Science & Technology

    2012-10-01

    Consequently, injury to cartilage in the articulating joints from trauma results in scar formation and possible arthritic changes that can lead to...chondrocytes to articular cartilage defects in the swine knee joint. Data from year 1 showed that the photochemical crosslinking of collagen gel...Isaksson O, Peterson L. Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation. N Engl J Med. 1994 Oct 6;331(14):889

  3. Role of Piezo Channels in Joint Health and Injury.

    PubMed

    Lee, W; Guilak, F; Liedtke, W

    2017-01-01

    Cartilage is an intrinsically mechanically sensitive tissue composed of chondrocytes as the only cell type. Chondrocyte mechanotransduction is not well understood, but recently we identified critical components of the mechanotransduction machinery demonstrating how mechanical stimulation of these cells can be converted into cellular calcium signals. Physiologic mechanical cues induce anabolic responses of (post-mitotic) chondrocytes via transient receptor potential vanilloid 4 ion channels, whereas injurious mechanical stress is transduced by Piezo1 jointly with Piezo2 ion channels. This chapter sheds light on the latter discovery and provides a rationale for follow-up questions, such as the nature of interaction between Piezo1 and Piezo2, and their tethering to the cytoskeleton. These recent insights can be leveraged toward translational medical progress to benefit diagnosis and treatment of osteoarthritis, representing a large and growing unmet medical need in the United States and large parts of the world. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Lower extremity joint position sense in runners with and without a history of knee overuse injury.

    PubMed

    Foch, Eric; Milner, Clare E

    2012-07-01

    Kinematic and kinetic analyses are routinely implemented to determine if gait differences exist between runners with and without a history of knee injury. Hip and knee kinematic differences have been reported between knee injured and non-injured runners. Yet, there is no consensus on whether these differences are the primary variables contributing to knee injury. Furthermore, there may be additional underlying factors that contribute to the development of injury that cannot be determined by gait analysis. The purpose of this investigation was to determine if joint position sense differences exist in runners with and without a history of knee overuse injury. Sagittal plane knee and hip joint position sense was measured in 13 runners with a history of knee overuse injury and 13 runners with no history of knee overuse injury. Absolute joint position replication error was measured during both a weight bearing and a non-weight bearing condition. Joint position replication errors at each joint were compared among groups and task using a two-way ANOVA with joint task as the repeated measure. Knee and hip joint replication errors were similar between both groups. The weight bearing and non-weight bearing tasks resulted in similar joint position replication errors. There were no interaction effects. In conclusion, knee flexion and hip adduction joint position sense is similar in runners with and without a history of knee overuse injury. Therefore, joint position sense measured via weight bearing and non-weight bearing joint position replication tasks may not play an important role in the development of knee overuse injury.

  5. Generalized Joint Laxity and Ligament Injuries in High School–Aged Female Volleyball Players in Japan

    PubMed Central

    Sueyoshi, Ted; Emoto, Gen; Yuasa, Tomoki

    2016-01-01

    Background: Generalized joint laxity has been linked to ligamentous injuries such as anterior cruciate ligament tear and ankle sprain. Purpose/Hypothesis: The purpose of this study was to investigate generalized joint laxity and incidence of ligament injuries in high school–aged female volleyball players. It was hypothesized that volleyball players with a past history of sprains would have increased generalized joint laxity compared with those without any history and that athletes with multiple sprains would demonstrate with a higher generalized joint laxity score than those who had only 1 sprain. Study Design: Case-control study; Level of evidence, 3. Methods: Forty-seven subjects were tested for generalized joint laxity using the Beighton and Horan Joint Mobility Index (BHJMI). They were categorized into 2 groups based on the presence of past ligament injury: injury group (IG) and noninjury group (NG). The IG group was further divided into 2 groups based on whether they had a single ligamentous injury (IGS) or multiple injuries (IGM) in the past to study whether there was any difference in scores between the subgroups. The collected data were analyzed statistically with 1-way analysis of variance. Results: Subjects in the IG group scored significantly higher on the BHJMI than those in the NG group. The mean score for the IG group was 2.40 ± 1.42, as opposed to 1.24 ± 1.09 for the NG group (P = .006). Eleven subjects in the IG group had suffered multiple injuries or recurrent injuries (IGM) and scored significantly higher than the remaining 19 individuals in the IG group, who had only sustained a single injury (IGS). The mean BHJMI scores were 3.18 ± 1.47 and 1.95 ± 1.22 for IGM and IGS, respectively (P = .02). Conclusion: Female athletes with a high generalized joint laxity score may be more prone to ligament injury and potentially to recurrent ligament injuries. PMID:27761474

  6. Generalized Joint Laxity and Ligament Injuries in High School-Aged Female Volleyball Players in Japan.

    PubMed

    Sueyoshi, Ted; Emoto, Gen; Yuasa, Tomoki

    2016-10-01

    Generalized joint laxity has been linked to ligamentous injuries such as anterior cruciate ligament tear and ankle sprain. The purpose of this study was to investigate generalized joint laxity and incidence of ligament injuries in high school-aged female volleyball players. It was hypothesized that volleyball players with a past history of sprains would have increased generalized joint laxity compared with those without any history and that athletes with multiple sprains would demonstrate with a higher generalized joint laxity score than those who had only 1 sprain. Case-control study; Level of evidence, 3. Forty-seven subjects were tested for generalized joint laxity using the Beighton and Horan Joint Mobility Index (BHJMI). They were categorized into 2 groups based on the presence of past ligament injury: injury group (IG) and noninjury group (NG). The IG group was further divided into 2 groups based on whether they had a single ligamentous injury (IGS) or multiple injuries (IGM) in the past to study whether there was any difference in scores between the subgroups. The collected data were analyzed statistically with 1-way analysis of variance. Subjects in the IG group scored significantly higher on the BHJMI than those in the NG group. The mean score for the IG group was 2.40 ± 1.42, as opposed to 1.24 ± 1.09 for the NG group (P = .006). Eleven subjects in the IG group had suffered multiple injuries or recurrent injuries (IGM) and scored significantly higher than the remaining 19 individuals in the IG group, who had only sustained a single injury (IGS). The mean BHJMI scores were 3.18 ± 1.47 and 1.95 ± 1.22 for IGM and IGS, respectively (P = .02). Female athletes with a high generalized joint laxity score may be more prone to ligament injury and potentially to recurrent ligament injuries.

  7. The Alternating Surface Segmented Lap Joint: a Design for Thin Highly Loaded Joints

    NASA Technical Reports Server (NTRS)

    Watkins, V. E., Jr.; Firth, G. C.

    1985-01-01

    The combination of thin airfoil sections and high aerodynamic loads on many wind tunnel models presents a major problem for attachment of flap elements. Conventional methods of attaching fixed control elements such as lap and tongue-in-groove joints are not rigid enough to provide surface continuity required in high Reynolds number research. For the extreme cases, the solution has been to fabricate separate wings for each flap setting with the flap element being and integral part of the wing. Here an attractive solution to this problem, the alternating surface segmented lap joint, is discussed. This joint provides increased rigidity and lower stress levels than conventional joints. Additionally, attachment fastener loading is low and the joint can be designed to accommodate high shear levels due to bending without the use of dowel pins.

  8. Contractures in burn injury part II: investigating joints of the hand.

    PubMed

    Schneider, Jeffrey C; Holavanahalli, Radha; Helm, Phala; O'Neil, Carina; Goldstein, Richard; Kowalske, Karen

    2008-01-01

    This study prospectively examines the incidence and severity of hand contractures after burn injury and determines predictors of contracture development. Data were collected prospectively from 1993 to 2002 for adult burn survivors admitted to a regional burn center. Demographic and medical data were collected on each subject. Primary outcome measures include presence of contractures, number of contractures, and the severity of contractures at each of the hand joints at hospital discharge. The metacarpal-phalangeal, proximal inter-phalangeal (PIP), and distal inter-phalangeal joints of all digits and the wrist joints are included in this study. Regression analysis was performed to determine predictors of the presence, severity, and number of contractures. Of the 985 study patients, 23% demonstrated at least one hand contracture at hospital discharge. Those with a contracture averaged ten contractures per person. Most contractures were mild (48%) or moderate (41%) in severity. The wrist was the most frequently affected joint (22%). Statistically significant predictors of contracture development include concomitant medical problems, total body surface area grafted and presence of hand burn and hand grafting (P < .05). Predictors of the number of contractures include length of stay, concomitant medical problems, burn size and presence of hand burn and grafting (P < .05). Contractures of the hand are a significant complication of burn injury. Clinicians can use the contracture predictors to help target interventions for those patients most at risk of developing hand contractures. Given the functional importance of the hand in daily living, the burn care community is challenged to find new ways of preventing and treating hand contractures.

  9. Effects of bearing surfaces on lap joint energy dissipation

    SciTech Connect

    Kess, H. R.; Rosnow, N. J.; Sidle, B. C.

    2001-01-01

    Energy is dissipated in mechanical systems in several forms. The major contributor to damping in bolted lap joints is friction, and the level of damping is a function of stress distribution in the bearing surfaces. This study examines the effects of bearing surface configuration on lap joint energy dissipation. The examination is carried out through the analysis of experimental results in a nonlinear framework. Then finite element models are constructed in a nonlinear framework to simulate the results. The experimental data were analyzed using piecewise linear log decrement. Phenomenological and non-phenomenological mathematical models were used to simulate joint behavior. Numerical results of experiments and analyses are presented.

  10. Decreased Knee Joint Loading Associated With Early Knee Osteoarthritis After Anterior Cruciate Ligament Injury

    PubMed Central

    Wellsandt, Elizabeth; Gardinier, Emily S.; Manal, Kurt; Axe, Michael J.; Buchanan, Thomas S.; Snyder-Mackler, Lynn

    2015-01-01

    Background Anterior cruciate ligament (ACL) injury predisposes individuals to early-onset knee joint osteoarthritis (OA). Abnormal joint loading is apparent after ACL injury and reconstruction. The relationship between altered joint biomechanics and the development of knee OA is unknown. Hypothesis Altered knee joint kinetics and medial compartment contact forces initially after injury and reconstruction are associated with radiographic knee OA 5 years after reconstruction. Study Design Case-control study; Level of evidence, 3. Methods Individuals with acute, unilateral ACL injury completed gait analysis before (baseline) and after (posttraining) preoperative rehabilitation and at 6 months, 1 year, and 2 years after reconstruction. Surface electromyographic and knee biomechanical data served as inputs to an electromyographically driven musculoskeletal model to estimate knee joint contact forces. Patients completed radiographic testing 5 years after reconstruction. Differences in knee joint kinetics and contact forces were compared between patients with and those without radiographic knee OA. Results Patients with OA walked with greater frontal plane interlimb differences than those without OA (nonOA) at baseline (peak knee adduction moment difference: 0.00 ± 0.08 N·m/kg·m [nonOA] vs −0.15 ± 0.09 N·m/kg·m [OA], P = .014; peak knee adduction moment impulse difference: −0.001 ± 0.032 N·m·s/kg·m [nonOA] vs −0.048 ± 0.031 N·m·s/kg·m [OA], P = .042). The involved limb knee adduction moment impulse of the group with osteoarthritis was also lower than that of the group without osteoarthritis at baseline (0.087 ± 0.023 N·m·s/kg·m [nonOA] vs 0.049 ± 0.018 N·m·s/kg·m [OA], P = .023). Significant group differences were absent at posttraining but reemerged 6 months after reconstruction (peak knee adduction moment difference: 0.02 ± 0.04 N·m/kg·m [nonOA] vs −0.06 ± 0.11 N·m/kg·m [OA], P = .043). In addition, the OA group walked with lower peak

  11. Turf-toe: a shoe-surface related football injury.

    PubMed

    Bowers, K D; Martin, R B

    1976-01-01

    Plantar capsule-ligament sprain of the great toe metatarsophalangeal joint, herein referred to as "turf-toe," is discussed with emphasis on two apparantly predisposing factors, playing surface hardness and shoe stiffness. Surface hardness studies have previously been performed by the authors on natural grass and AstroTurf. A study of football shoe flexibility is presented and the results correlated with the occurrence of turftoe. We have not encountered this entity in players wearing relatively stiff conventional seven posted football shoes or the more flexible soccer style shoe on natural grass fields. We have found it to be a not uncommon injury among players wearning the soccer style shoe on AstroTurf.

  12. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2014-10-01

    Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK) "Assessment of Biomarkers Associated with Joint Injury and Subsequent Post...Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK) 1. INTRODUCTION...Associated with Joint Injury and Subsequent Post-Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and

  13. Bilateral sacroiliac joint dislocation (anterior and posterior) with triradiate cartilage injury: a case report.

    PubMed

    Lee, Dae-Hee; Jeong, Woong-Kyo; Inna, Prashanth; Noh, Won; Lee, Dong-Ki; Lee, Soon-Hyuck

    2011-12-01

    Pediatric sacroiliac joint injuries are uncommon. Significant pelvis ring disruptions in children are rare, and their management is complicated by patient size, differences in bony architecture, and future growth and remodeling potential. We present a rare case of anterior sacroiliac joint dislocation associated with triradiate cartilage injury with a posterior sacroiliac dislocation on the contralateral side. This appears to be the first such case reported in the literature.

  14. Treatment of soft tissue injuries to the dorsum of the metacarpophalangeal joint (Boxer's knuckle).

    PubMed

    Arai, K; Toh, S; Nakahara, K; Nishikawa, S; Harata, S

    2002-02-01

    We retrospectively reviewed the surgical treatment for 16 cases of traumatic soft tissue injury to the metacarpophalangeal joint (Boxer's knuckle). A history of trauma was present in all cases and there was an associated extensor tendon dislocation in seven cases. Eight cases were initially treated conservatively, but their symptoms persisted. Intraoperative findings included rupture of the extensor hood or joint capsule in all cases. Surgical closure of the rupture of the joint capsule resulted in a successful outcome in all cases. We consider that conservative treatment of this injury may not be effective when the joint capsule of the metacarpophalangeal joint is ruptured. We recommend arthrography of the metacarpophalangeal joint to assist in the decision as to whether to proceed with surgical or conservative treatment.

  15. Soluble Flt-1 improves the repair of ankle joint injury in rats

    PubMed Central

    Tian, Jing; Xie, Bing; Xiang, Liangbi; Zhao, Yong; Zhou, Dapeng

    2016-01-01

    The ankle injuries create great pain to a great number of patients worldwide. Past studies have focused on the development of practical treatments to relieve pain and improve recovery, but the molecular mechanisms underlying the ankle injuries, especially the local inflammation in the damaged ankle joint, have been rarely studied. Moreover, although reduction of production and secretion of pro-inflammatory cytokines may reduce the pain and promote the recovery, a practical approach is currently lacking. Here, we detected significantly higher levels of placental growth factor (PLGF) and pro-inflammatory cytokines in the joint fluid from the patients of acute ankle joint injury (AAJI). Interestingly, the levels of PLGF and pro-inflammatory cytokines in the joint fluid strongly correlated. In order to examine whether PLGF may regulate the production and secretion of pro-inflammatory cytokines in the injured joint, we used a rat carrageenan-induced ankle injury model for AAJI in humans. We injected soluble Flt-1 (sFlt-1) into the articular cavity of the injured ankle joint to block PLGF signaling and found that injection of sFlt-1 significantly improved the rat behavior in activity wheels test, which appeared to result from reduced secretion of the pro-inflammatory cytokines in the ankle joint. Thus, our study suggests that blocking PLGF signaling may be a novel therapeutic approach for treating AAJI in humans. PMID:27904694

  16. Sock systems to prevent foot blisters and the impact on overuse injuries of the knee joint.

    PubMed

    Van Tiggelen, Damien; Wickes, Simon; Coorevits, Pascal; Dumalin, Mich; Witvrouw, Erik

    2009-02-01

    The incidence of foot blisters and other overuse injuries of the lower limb is very high during basic military training (BMT). One hundred and eighty-nine subjects were divided into two intervention groups wearing alternative sock systems and one control group. Overall, 57% of the 173 recruits who completed the training, developed foot blisters. Binary logistic regression revealed the type of sock, race, previous hiking or military experience, and known orthopedic foot conditions to be predictive variables for foot blisters. Fifty-three percent of the 173 recruits also developed another overuse injury of the lower limb (25.4% related to the knee joint). Previous military or hiking experience and the association of foot blisters revealed to be predictive for the overuse injuries of the knee joint. The results of the present study suggest associated foot blisters are also an important factor in the development of overuse injuries of the knee joint during BMT.

  17. A review of synthetic playing surfaces, the shoe-surface interface, and lower extremity injuries in athletes.

    PubMed

    Taylor, Samuel A; Fabricant, Peter D; Khair, M Michael; Haleem, Amgad M; Drakos, Mark C

    2012-11-01

    The evolution of synthetic playing surfaces began in the 1960s and has had an impact on field use, shoe-surface dynamics, and the incidence of sports-related injuries. Modern third-generation turfs are being installed in recreational facilities and professional stadiums worldwide. Currently, > two-thirds of National Football League teams, > 100 National Collegiate Athletic Association Division I football teams, and > 1000 high schools in the United States have installed synthetic playing surfaces. Those in favor of such playing surfaces note their unique combination of versatility and durability; they can be used in both ideal and inclement weather conditions. However, the more widespread installation and use of these surfaces have raised questions and concerns regarding the impact of artificial turf on the type and severity of sports-related injuries. There appears to be no question that the shoe-surface interface has a significant impact on such injuries. Independent variables such as weather conditions, contact versus noncontact sport, shoe design, and field wear complicate many of the results reported in the literature, thereby preventing an accurate assessment of the true risk(s) associated with certain shoe-surface combinations. Historically, studies suggest that artificial turf is associated with a higher incidence of injury. Furthermore, reliable biomechanical data suggest that both the torque and strain experienced by lower extremity joints generated by artificial surfaces may be more than those generated by natural grass fields. Recent data from the National Football League support this theory and suggest that elite athletes may sustain more injuries, even when playing on the newer artificial surfaces. By contrast, some reports based on data collected from lower-level athletes suggest that artificial turf may protect against injury. This review discusses the history of artificial surfaces, the biomechanics of the shoe-surface interface, and some common

  18. Pain from intra-articular NGF or joint injury in the rat requires contributions from peptidergic joint afferents.

    PubMed

    Kras, Jeffrey V; Weisshaar, Christine L; Pall, Parul S; Winkelstein, Beth A

    2015-09-14

    Non-physiological stretch of the cervical facet joint's capsular ligament induces persistent behavioral hypersensitivity and spinal neuronal hyperexcitability via an intra-articular NGF-dependent mechanism. Although that ligament is innervated by nociceptors, it is unknown if a subpopulation is exclusively responsible for the behavioral and spinal neuronal responses to intra-articular NGF and/or facet joint injury. This study ablated joint afferents using the neurotoxin saporin targeted to neurons involved in either peptidergic ([Sar(9),Met (O2)(11)]-substance P-saporin (SSP-Sap)) or non-peptidergic (isolectin B4-saporin (IB4-Sap)) signaling to investigate the contributions of those neuronal populations to facet-mediated pain. SSP-Sap, but not IB4-Sap, injected into the bilateral C6/C7 facet joints 14 days prior to an intra- articular NGF injection prevents NGF-induced mechanical and thermal hypersensitivity in the forepaws. Similarly, only SSP- Sap prevents the increase in mechanical forepaw stimulation- induced firing of spinal neurons after intra-articular NGF. In addition, intra-articular SSP-Sap prevents both behavioral hypersensitivity and upregulation of NGF in the dorsal root ganglion after a facet joint distraction that normally induces pain. These findings collectively suggest that disruption of peptidergic signaling within the joint may be a potential treatment for facet pain, as well as other painful joint conditions associated with elevated NGF, such as osteoarthritis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. [The relationship between whiplash injury and temporomandibular joint dysfunction].

    PubMed

    Barak, Shlomo

    2013-10-01

    This article aims to discuss the possible relationship between rapid extension-flexion of the neck-whiplash injury and temporomandibular disorders (TMD). Clinical experience and studies revealed that whiplash injury may cause TMD. The pathophysiology of TMD is described as well as clinical and imaging diagnostic criteria. The treatment modalities for TMD are: physiotherapy, nonsteroidal anti-inflammatory drugs and occlusal splints.

  20. Cricket fast bowling workload patterns as risk factors for tendon, muscle, bone and joint injuries.

    PubMed

    Orchard, John W; Blanch, Peter; Paoloni, Justin; Kountouris, Alex; Sims, Kevin; Orchard, Jessica J; Brukner, Peter

    2015-08-01

    To assess workload-related risk factors for injuries to particular tissue types in cricket fast bowlers. 235 fast bowlers who bowled in 14600 player innings over a period of 15 years were followed in a prospective cohort risk factor study to compare overs bowled in each match (including preceding workload patterns) and injury risk in the 3-4 weeks subsequent to the match. Injuries were categorised according to the affected tissue type as either: bone stress, tendon injuries, muscle strain or joint injuries. Workload risk factors were examined using binomial logistic regression multivariate analysis, with a forward stepwise procedure requiring a significance of <0.05. High acute match workload and high previous season workload were risk factors for tendon injuries, but high medium term (3-month workload) was protective. For bone stress injuries, high medium term workload and low career workload were risk factors. For joint injuries, high previous season and career workload were risk factors. There was little relationship between muscle injury and workload although high previous season workload was slightly protective. The level of injury risk for some tissue types varies in response to preceding fast bowling workload, with tendon injuries most affected by workload patterns. Workload planning may need to be individualised, depending on individual susceptibility to various injury types. This study supports the theory that tendons are at lowest risk with consistent workloads and susceptible to injury with sudden upgrades in workload. Gradual upgrades are recommended, particularly at the start of a bowler's career to reduce the risk of bone stress injury. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. Textured bearing surface in artificial joints to reduce macrophage activation

    NASA Astrophysics Data System (ADS)

    Nakanishi, Yoshitaka; Nishi, Naoki; Chikaura, Hiroto; Nakashima, Yuta; Miura, Hiromasa; Higaki, Hidehiko; Mizuta, Hiroshi; Iwamoto, Yukihide; Fujiwara, Yukio; Komohara, Yoshihiro; Takeya, Motohiro

    2015-12-01

    Micro slurry-jet erosion has been proposed as a precision machining technique for the bearing surfaces of artificial joints in order to reduce the total amount of polyethylene wear and to enlarge the size of the wear debris. The micro slurry-jet erosion method is a wet blasting technique which uses alumina particles as the abrasive medium along with compressed air and water to create an ideal surface. Pin-on-disc wear tests with multidirectional sliding motion on the textured surface of a \\text{Co}-\\text{Cr}-\\text{Mo} alloy counterface for polyethylene resulted in both a reduction of wear as well as enlargement of the polyethylene debris size. In this study, primary human peripheral blood mononuclear phagocytes were incubated with the debris, and it was elucidated that the wear debris generated on the textured surface regulated secretion of the proinflammatory cytokines IL-6 and TNF-α, indicating a reduction in the induced tissue reaction and joint loosening.

  2. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Finish of surface joints. 18.33 Section 18.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and...

  3. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Finish of surface joints. 18.33 Section 18.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and...

  4. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Finish of surface joints. 18.33 Section 18.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and...

  5. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Finish of surface joints. 18.33 Section 18.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and...

  6. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Finish of surface joints. 18.33 Section 18.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and...

  7. Joint Air-to-Surface Standoff Missile (JASSM)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-555 Joint Air-to-Surface Standoff Missile (JASSM) As of FY 2017 President’s Budget Defense...Office Estimate RDT&E - Research, Development, Test, and Evaluation SAR - Selected Acquisition Report SCP - Service Cost Position TBD - To Be Determined

  8. Spinal neuronal plasticity is evident within 1 day after a painful cervical facet joint injury.

    PubMed

    Crosby, Nathan D; Weisshaar, Christine L; Winkelstein, Beth A

    2013-05-10

    Excessive stretch of the cervical facet capsular ligament induces persistent pain and spinal plasticity at later time points. Yet, it is not known when such spinal modifications are initiated following this painful injury. This study investigates the development of hyperalgesia and neuronal hyperexcitability in the spinal cord after a facet joint injury. Behavioral sensitivity was measured in a model of painful C6/C7 facet joint injury in the rat, and neuronal hyperexcitability in the spinal cord was evaluated at 6h and 1 day after injury or a sham procedure, in separate groups. Extracellular recordings of C6/C7 dorsal horn neuronal activity (229 neurons) were used to quantify spontaneous and evoked firing. Rats exhibited no change in sensitivity to mechanical stimulation of the forepaw at 6h, but did exhibit increased sensitivity at 1 day after injury (p=0.012). At 6h, both spontaneous neuronal activity and firing evoked by light brushing, pinch, and von Frey filaments (1.4-26g) applied at the forepaw were not different between sham and injury. At 1 day, spontaneous firing was noted in a greater number of neurons after injury than sham (p<0.04). Evoked firing was also increased 1 day after injury compared to normal and sham (p<0.03). Dorsal horn hyperexcitability and increased spontaneous firing developed between 6 and 24h after painful facet injury, suggesting that the development of hyperalgesia parallels dorsal horn hyperexcitability following mechanical facet joint injury, and these spinal mechanisms are initiated as early as 1 day after injury.

  9. [Diagnosis of medial collateral ligament injury by stress X-ray and MRI of knee joint].

    PubMed

    Zhang, Long-Jun; Chen, Jian-Liang; Xu, Yong; Zhu, Shao-Bing

    2012-11-01

    To study the application of stress X-ray of knee joint for the diagnosis ot medial collateral ligament injury. From January 2008 to June 2011, 46 patients with medial collateral ligament injury were reviewed. Among the patients, 32 patients were male and 14 patients were female, ranging in age from 28 to 72 years, with an average of (49.46 +/- 22.54) years. Left knee joint injuries occurred in 22 patients, and 24 patients had injuries in right knee joint. Thirty-one patients were treated with surgical method, and 15 patients were treated with conservative method including 1 patient finally received operation after 3 months treatment with conservative method without effect. The injury side and normal side were observed by X-ray under stress and non-stress, as well as MRI. Operation was used to treat patients with medial gap markedly widen and the deep layer of medial collateral ligament injury in MRI. A line (line A) was drawn from medial condyle to lateral condyle of tibia platform. The line A was translated to the inner margin of condylus medialis femoris, which was line B. The perpendicular distance was measured, which was line C. The ration of space difference (R) was calculated by (space at stress force of injured side-space at non-stress force of injured side)/(space at stress force of normal side-space at non-stress force of normal side). The relationship between R and ligament injury type were investigated. There were 17 patients with injuries of superficial lamella, 21 patients with injuries of deep lamella. Eight patients had associated injuries of articular capsule and posterior cruciate ligament. When R value was between 1.51 to 5.24, the injury of superficial ligament was found in 15 patients, actual injuries were found in 17 patients. When R value between 5.28 and 13.85, the injuries of bathypelagic ligament were found in 19 patients, actual injuries were found in 21 patients. When R value was between 15.61 and 26.25, the associated injuries of

  10. Injuries and disorders among young ice skaters: relationship with generalized joint laxity and tightness

    PubMed Central

    Okamura, Shinobu; Wada, Naoki; Tazawa, Masayuki; Sohmiya, Makoto; Ibe, Yoko; Shimizu, Toru; Usuda, Shigeru; Shirakura, Kenji

    2014-01-01

    This study retrospectively investigated 192 teenage speed and figure skaters with prior injuries documented by an athletes’ questionnaire, who underwent a physical examination to assess their muscle tightness and generalized joint laxity. In all athletes, the degree of muscle tightness and joint laxity were measured by a standardized physical examination. A descriptive report of the types of injuries showed a predominance of fractures, ligament injuries, enthesitis, and lower back pain. Approximately 5% of all skaters tested positive for tightness, while 25.8% of figure skaters and 15.2% of speed skaters had generalized ligamentous laxity. Statistical testing showed an association between ankle sprains and muscle tightness, and an association between knee enthesitis and muscle tightness in skating athletes. There was also an association between lower back pain and generalized joint laxity, which held true only for the male skaters. PMID:25177155

  11. Injuries and disorders among young ice skaters: relationship with generalized joint laxity and tightness.

    PubMed

    Okamura, Shinobu; Wada, Naoki; Tazawa, Masayuki; Sohmiya, Makoto; Ibe, Yoko; Shimizu, Toru; Usuda, Shigeru; Shirakura, Kenji

    2014-01-01

    This study retrospectively investigated 192 teenage speed and figure skaters with prior injuries documented by an athletes' questionnaire, who underwent a physical examination to assess their muscle tightness and generalized joint laxity. In all athletes, the degree of muscle tightness and joint laxity were measured by a standardized physical examination. A descriptive report of the types of injuries showed a predominance of fractures, ligament injuries, enthesitis, and lower back pain. Approximately 5% of all skaters tested positive for tightness, while 25.8% of figure skaters and 15.2% of speed skaters had generalized ligamentous laxity. Statistical testing showed an association between ankle sprains and muscle tightness, and an association between knee enthesitis and muscle tightness in skating athletes. There was also an association between lower back pain and generalized joint laxity, which held true only for the male skaters.

  12. Joint Global War on Terror (GWOT) Vascular Injury Study 2

    DTIC Science & Technology

    2015-02-01

    underway and we have developed the surveillance program design and identified Service Members who incurred vascular injury. To date, four research nurse ...Current study staff consists of a program manager and four research nurses . The GWOT 2 Wartime Vascular Injury Study is an ongoing effort; therefore, the... Nurse , 2-4 April 2014, poster presentation o Vascular discharge education and follow-up care subsequent to wartime vascular trauma; Presented in San

  13. Unusual exostosis formation of the subtalar joint following an inversion ankle injury.

    PubMed

    Cisco, R W; Shaffer, M; Kuchler, L

    1993-01-01

    Exostosis formation following trauma isnot uncommon to the joints of the foot and ankle. The etiology and treatment of these boney lesions is well-documented in the literature. The following is a report of an unusual exostosis of the subtalar joint following inversion ankle injury. This case is unusual in respect to the formation of an adventitious articulation, the size of the lesion, and the pathology.

  14. Efficacy of stepwise application of orthosis and kinesiology tape for treating thumb metacarpophalangeal joint hyperextension injury.

    PubMed

    Lee, Sun-Min; Lee, Jung-Hoon

    2015-08-01

    [Purpose] The purpose of this study was to investigate on the effects of the stepwise application of orthosis and kinesiology tape on a patient with thumb metacarpophalangeal joint hyperextension injury. [Subject] The patient was a 43-year-old man with severe thumb MCP pain and extremely limited thumb movement. [Methods] Stepwise application of orthosis and kinesiology taping were performed for 3 weeks and 4 weeks, respectively. [Results] After stepwise treatment, the patient was able to power grip, precision pinch, turn a key, and hold a pen without pain. [Conclusion] Stepwise application of thumb orthosis and kinesiology tape is a safe and effective treatment for thumb MCP joint hyperextension injury.

  15. Isolated radial volar dislocation of the fifth carpometacarpal joint :a rare injury

    PubMed Central

    El Kadi, Khalid Ibn; Sbiyaa, Mohcine; Alami, Badr; Rabhi, Ilyass; Marzouki, Amine; Lahrach, Kamal; Boutayeb, Fawzi

    2013-01-01

    Isolated palmar dislocation of the fifth carpometacarpal joint is an uncommon injury and classified as radio-palmar or ulno-palmar according to the direction of displacement of the fifth metacarpal base. This very rare injury is often difficult to recognize. A careful neurologic assessment of the patient is a necessity, as well as obtaining proper radiographs of the hand. The purpose of this report is to present a patient with a pure isolated volar dislocation of the fifth carpometacarpal joint that was satisfactorily treated with closed reduction and casting. A review of the literature is presented. PMID:24711880

  16. Efficacy of stepwise application of orthosis and kinesiology tape for treating thumb metacarpophalangeal joint hyperextension injury

    PubMed Central

    Lee, Sun-Min; Lee, Jung-Hoon

    2015-01-01

    [Purpose] The purpose of this study was to investigate on the effects of the stepwise application of orthosis and kinesiology tape on a patient with thumb metacarpophalangeal joint hyperextension injury. [Subject] The patient was a 43-year-old man with severe thumb MCP pain and extremely limited thumb movement. [Methods] Stepwise application of orthosis and kinesiology taping were performed for 3 weeks and 4 weeks, respectively. [Results] After stepwise treatment, the patient was able to power grip, precision pinch, turn a key, and hold a pen without pain. [Conclusion] Stepwise application of thumb orthosis and kinesiology tape is a safe and effective treatment for thumb MCP joint hyperextension injury. PMID:26355325

  17. Automated inspection of solder joints for surface mount technology

    NASA Technical Reports Server (NTRS)

    Savage, Robert M.; Park, Hyun Soo; Fan, Mark S.

    1993-01-01

    Researchers at NASA/GSFC evaluated various automated inspection systems (AIS) technologies using test boards with known defects in surface mount solder joints. These boards were complex and included almost every type of surface mount device typical of critical assemblies used for space flight applications: X-ray radiography; X-ray laminography; Ultrasonic Imaging; Optical Imaging; Laser Imaging; and Infrared Inspection. Vendors, representative of the different technologies, inspected the test boards with their particular machine. The results of the evaluation showed limitations of AIS. Furthermore, none of the AIS technologies evaluated proved to meet all of the inspection criteria for use in high-reliability applications. It was found that certain inspection systems could supplement but not replace manual inspection for low-volume, high-reliability, surface mount solder joints.

  18. Designing prosthetic knee joints with bio-inspired bearing surfaces

    PubMed Central

    Qiu, Mingfeng; Chyr, Anthony; Sanders, Anthony P.; Raeymaekers, Bart

    2014-01-01

    It has long been known that articular cartilage exhibits a surface microtexture with shallow indentations. By contrast, prosthetic joints consist of ultra-smooth bearing surfaces, the longevity of which does not reach that of natural cartilage. We show that adding a microtexture to the smooth femoral component of a prosthetic knee joint reduces friction by increasing the lubricant film thickness between the bearing surfaces of the knee. We have implemented an elastohydrodynamic lubrication model to optimize the geometry of the microtexture, while taking into account the deformation of the polyethylene tibial insert. We have manufactured several microtexture designs on a surrogate femoral component, and experimentally demonstrate that the microtexture reduces friction between the surrogate femoral component and tibial insert. PMID:25049441

  19. Designing prosthetic knee joints with bio-inspired bearing surfaces.

    PubMed

    Qiu, Mingfeng; Chyr, Anthony; Sanders, Anthony P; Raeymaekers, Bart

    2014-09-01

    It has long been known that articular cartilage exhibits a surface microtexture with shallow indentations. By contrast, prosthetic joints consist of ultra-smooth bearing surfaces, the longevity of which does not reach that of natural cartilage. We show that adding a microtexture to the smooth femoral component of a prosthetic knee joint reduces friction by increasing the lubricant film thickness between the bearing surfaces of the knee. We have implemented an elastohydrodynamic lubrication model to optimize the geometry of the microtexture, while taking into account the deformation of the polyethylene tibial insert. We have manufactured several microtexture designs on a surrogate femoral component, and experimentally demonstrate that the microtexture reduces friction between the surrogate femoral component and tibial insert.

  20. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post Traumatic Arthritis

    DTIC Science & Technology

    2015-10-01

    Injury and Subsequent Post-Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK...of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak...2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK) 1. INTRODUCTION: Post-traumatic arthritis (PTA) is a clinically

  1. Elbow joint stability following experimental osteoligamentous injury and reconstruction.

    PubMed

    Deutch, Søren R; Jensen, Steen L; Tyrdal, Stein; Olsen, Bo S; Sneppen, Otto

    2003-01-01

    Elbow joint dislocation was simulated in cadaveric specimens to quantify laxity induced by radial head and coronoid process lesions, either alone or in combination with collateral ligament insufficiency. The effects of lateral ligament reconstruction and radial head prosthesis replacement were also considered. Absence of the radial head and the coronoid process induced rotatory laxity of 145% and 128% (both P <.01), respectively, compared with the intact joint. When both were absent, the joints subluxated regardless of collateral ligament status. Isolated radial head prosthesis implantation prevented this subluxation, and laxity almost normalized. Lateral collateral ligament reconstruction prevented major laxity even in the absence of the radial head. Lateral collateral ligament reconstruction and radial head prosthetic replacement yielded restraint against gross instability in the maximal unstable situation (terrible triad). The lateral collateral ligament is the prime stabilizer to external rotation, and reconstruction of this alone, even with an absent radial head, is beneficial.

  2. Tenodesis for restoration of distal interphalangeal joint flexion in unrepairable flexor digitorum profundus injuries.

    PubMed

    Pritsch, Tamir; Sammer, Douglas M

    2014-01-01

    To describe in a cadaveric model a tenodesis procedure for restoring distal interphalangeal joint flexion in patients with unrepairable isolated flexor digitorum profundus (FDP) injuries. In 16 fresh-frozen cadaveric fingers, the FDP tendon was transected 1 cm proximal to its insertion to simulate an isolated zone I laceration. The injury was reconstructed using a palmaris longus tendon graft to create a mechanical linkage between the interphalangeal joints, which restored coordinated interphalangeal joint flexion. Joint motion and the force required to flex and extend the fingers were tested before and after the tenodesis. After FDP zone I laceration, distal interphalangeal joint flexion with load applied to the flexor digitorum superficialis tendon averaged 2°. The FDP flexion increased to a mean of 57° after the tenodesis. The sum of metacarpophalangeal, proximal interphalangeal and distal interphalangeal joint flexion averaged 186° before the tenodesis and increased to 233° after the tenodesis. The force required to achieve fingertip to palm contact and the force required to fully extend the proximal interphalangeal joint were not altered. In this cadaveric model, this tenodesis successfully restored coordinated interphalangeal joint flexion after a simulated zone I FDP laceration with improvements in distal interphalangeal joint flexion and composite finger flexion. Critical factors such as the effects of inflammation, edema, soft tissue healing, and scar formation could not be evaluated and would likely affect the outcomes of this procedure. The in vivo results of this procedure are not known. The potential use of this tenodesis for treating unrepairable isolated zone I FDP injuries was demonstrated in a cadaveric model. Further investigation of the outcomes and complications in vivo would be required before routine clinical use. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  3. Ankylosis of temporomandibular joint after the traumatic brain injury: a report of two cases.

    PubMed

    Meng, Qinggong; Li, Bo; Long, Xing; Li, Jian; Yan, Quanmei

    2013-08-01

    Mouth opening limitation after the neurosurgical procedures is a common complication and usually resolves within 3 months. If limited mouth opening remains unresolved on the long term, an intra-articular ankylosis of temporomandibular joint may develop eventually. The possible mechanisms base on the myositis and atrophy of the masticatory muscles for these craniotomies are often involved in the temporalis. This article reports two unusual cases with the intra-articular ankylosis of temporomandibular joint after the traumatic brain injury, who received a modified surgical treatment for joint ankylosis. Therefore, the early diagnosis and intervention are important to minimize these complications. © 2011 John Wiley & Sons A/S.

  4. Whole limb kinematics are preferentially conserved over individual joint kinematics after peripheral nerve injury.

    PubMed

    Chang, Young-Hui; Auyang, Arick G; Scholz, John P; Nichols, T Richard

    2009-11-01

    Biomechanics and neurophysiology studies suggest whole limb function to be an important locomotor control parameter. Inverted pendulum and mass-spring models greatly reduce the complexity of the legs and predict the dynamics of locomotion, but do not address how numerous limb elements are coordinated to achieve such simple behavior. As a first step, we hypothesized whole limb kinematics were of primary importance and would be preferentially conserved over individual joint kinematics after neuromuscular injury. We used a well-established peripheral nerve injury model of cat ankle extensor muscles to generate two experimental injury groups with a predictable time course of temporary paralysis followed by complete muscle self-reinnervation. Mean trajectories of individual joint kinematics were altered as a result of deficits after injury. By contrast, mean trajectories of limb orientation and limb length remained largely invariant across all animals, even with paralyzed ankle extensor muscles, suggesting changes in mean joint angles were coordinated as part of a long-term compensation strategy to minimize change in whole limb kinematics. Furthermore, at each measurement stage (pre-injury, paralytic and self-reinnervated) step-by-step variance of individual joint kinematics was always significantly greater than that of limb orientation. Our results suggest joint angle combinations are coordinated and selected to stabilize whole limb kinematics against short-term natural step-by-step deviations as well as long-term, pathological deviations created by injury. This may represent a fundamental compensation principle allowing animals to adapt to changing conditions with minimal effect on overall locomotor function.

  5. Anterior Dislocation of Elbow Joint-Case Report of A Rare Injury

    PubMed Central

    Kumar, Rakesh; Sekhawat, Vishal; Sankhala, SS; Bijarnia, Isha

    2014-01-01

    Introduction: In view of the comparative frequency of posterior dislocations of the elbow, it is rather remarkable that anterior dislocations of that joint should be among the rarest of injuries. Authors report a case of acute anterior dislocation with old fracture of medial epicondyle. Case Report: 22 years old male presented with acute pain and tenderness with deformity of right elbow joint and inability to move the elbow joint after he fell down during an episode of seizure. There was no neurovascular deficit. Radiological examination confirmed anterior dislocation of elbow joint with an ununited medial epicondyle fracture. Elbow was reduced under general anesthesia in emergency operation theatre. Conclusion: Anterior dislocation of elbow is very rare. Early diagnosis and proper reduction of dislocation is key of normal functioning of elbow joint. PMID:27298973

  6. Non-terminal animal model of post-traumatic osteoarthritis induced by acute joint injury

    PubMed Central

    Boyce, Mary K.; Trumble, Troy N.; Carlson, Cathy S.; Groschen, Donna M.; Merritt, Kelly A.; Brown, Murray P.

    2013-01-01

    Objective Develop a non-terminal animal model of acute joint injury that demonstrates clinical and morphological evidence of early post-traumatic osteoarthritis (PTOA). Methods An osteochondral (OC) fragment was created arthroscopically in one metacarpophalangeal (MCP) joint of 11 horses and the contralateral joint was sham operated. Eleven additional horses served as unoperated controls. Every 2 weeks, force plate analysis, flexion response, joint circumference, and synovial effusion scores were recorded. At weeks 0 and 16, radiographs (all horses) and arthroscopic videos (OC injured and sham joints) were graded. At week 16, synovium and cartilage biopsies were taken arthroscopically from OC injured and sham joints for histologic evaluation and the OC fragment was removed. Results Osteochondral fragments were successfully created and horses were free of clinical lameness after fragment removal. Forelimb gait asymmetry was observed at week 2 (P=0.0012), while joint circumference (P<0.0001) and effusion scores (P<0.0001) were increased in injured limbs compared to baseline from weeks 2 to 16. Positive flexion response of injured limbs was noted at multiple time points. Capsular enthesophytes were seen radiographically in injured limbs. Articular cartilage damage was demonstrated arthroscopically as mild wear-lines and histologically as superficial zone chondrocyte death accompanied by mild proliferation. Synovial hyperemia and fibrosis were present at the site of OC injury. Conclusion Acute OC injury to the MCP joint resulted in clinical, imaging, and histologic changes in cartilage and synovium characteristic of early PTOA. This model will be useful for defining biomarkers of early osteoarthritis and for monitoring response to therapy and surgery. PMID:23467035

  7. Customized Fabrication of Osteochondral Tissue for Articular Joint Surface Repair

    DTIC Science & Technology

    2015-09-01

    it is a disease of the cartilage, bone and surrounding soft tissue that disables 9-10% of the US population. In the US military , combat and non...cartilage – it is a disease of the cartilage, bone and surrounding soft tissue that disables 9-10% of the US population. In the US military , combat and...1 AD______________ AWARD NUMBER: W81XWH-14-1-0217 TITLE: “Customized Fabrication of Osteochondral Tissue for Articular Joint Surface Repair

  8. Cartilage shear dynamics during tibio-femoral articulation: effect of acute joint injury and tribosupplementation on synovial fluid lubrication.

    PubMed

    Wong, B L; Kim, S H Chris; Antonacci, J M; McIlwraith, C Wayne; Sah, R L

    2010-03-01

    To determine the effects of acute injury and tribosupplementation by hyaluronan (HA) on synovial fluid (SF) modulation of cartilage shear during tibio-femoral articulation. Human osteochondral blocks from the lateral femoral condyle (LFC) and tibial plateau (LTP) were apposed, compressed 13%, and subjected to sliding under video microscopy. Tests were conducted with equine SF from normal joints (NL-SF), SF from acutely injured joints (AI-SF), and AI-SF to which HA was added (AI-SF+HA). Local and overall shear strain (E(xz)) and the lateral displacement (Deltax) at which E(xz) reached 50% of peak values (Deltax(1/2)) were determined. During articulation, LFC and LTP cartilage E(xz) increased with Deltax and peaked when surfaces slid, with peak E(xz) being maintained during sliding. With AI-SF as lubricant, surface and overall Deltax(1/2) were approximately 40% and approximately 20% higher, respectively, than values with NL-SF and AI-SF+HA as lubricant. Also, peak E(xz) was markedly higher with AI-SF as lubricant than with NL-SF as lubricant, both near the surface (approximately 80%) and overall (50-200%). Following HA supplementation to AI-SF, E(xz) was reduced from values with AI-SF alone by 30-50% near the surface and 20-30% overall. Magnitudes of surface and overall E(xz) were markedly (approximately 50 to 80%) higher in LTP cartilage than LFC cartilage for all lubricants. Acute injury impairs SF function, elevating cartilage E(xz) markedly during tibio-femoral articulation; such elevated E(xz) may contribute to post-injury associated cartilage degeneration. Since HA partially restores the function of AI-SF, as indicated by E(xz), tribosupplements may be beneficial in modulating normal cartilage homeostasis. Copyright 2009 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  9. Cartilage Shear Kinematics During Tibio-Femoral Articulation: Effect of Acute Joint Injury & Tribosupplementation on Synovial Fluid Lubrication

    PubMed Central

    Wong, Benjamin L.; Kim, Seung Hyun Chris; Antonacci, Jennifer M.; McIlwraith, C. Wayne; Sah, Robert L.

    2009-01-01

    Objective To determine the effects of acute injury and tribosupplementation by hyaluronan (HA) on synovial fluid (SF) modulation of cartilage shear during tibio-femoral articulation. Methods Human osteochondral blocks from the lateral femoral condyle (LFC) and tibial plateau (LTP) were apposed, compressed 13%, and subjected to sliding under video microscopy. Tests were conducted with equine SF from normal joints (NL-SF), SF from acutely injured joints (AI-SF), and AI-SF to which HA was added (AI-SF+HA). Local and overall shear strain (Exz) and the lateral displacement (Δx) at which Exz reached 50% of peak values (Δx1/2) were determined. Results During articulation, LFC and LTP cartilage Exz increased with Δx and peaked when surfaces slid, with peak Exz being maintained during sliding. With AI-SF as lubricant, surface and overall Δx1/2 were ~40% and ~20% higher, respectively than values with NL-SF and AI-SF+HA as lubricant. Also, peak Exz was markedly higher with AI-SF as lubricant than with NL-SF as lubricant, both near the surface (~80%) and overall (50–200%). Following HA supplementation to AI-SF, Exz was reduced from values with AI-SF alone by 30–50% near the surface and 20–30% overall. Magnitudes of surface and overall Exz were markedly (~50–80%) higher in LTP cartilage than LFC cartilage for all lubricants. Conclusion Acute injury impairs SF function, elevating cartilage Exz markedly during tibio-femoral articulation; such elevated Exz may contribute to post-injury associated cartilage degeneration. Since HA partially restores the function of AI-SF, as indicated by Exz, tribosupplements may be beneficial in restoring cartilage mechanobiology. PMID:20004636

  10. Joint inversion of surface and borehole magnetic amplitude data

    NASA Astrophysics Data System (ADS)

    Li, Zelin; Yao, Changli; Zheng, Yuanman; Yuan, Xiaoyu

    2016-04-01

    3D magnetic inversion for susceptibility distribution is a powerful tool in quantitative interpretation of magnetic data in mineral exploration. However, the inversion and interpretation of such data are faced with two problems. One problem is the poor imaging results of deep sources when only surface data are inverted. The other is the unknown total magnetization directions of sources when strong remanence exists. To deal with these problems simultaneously, we propose a method through the joint inversion of surface and borehole magnetic amplitude data. In this method, we first transform both surface and borehole magnetic data to magnetic amplitude data that are less sensitive to the directions of total magnetization, and then preform a joint inversion of the whole amplitude data to generate a 3D susceptibility distribution. The amplitude inversion algorithm uses Tikhonov regularization and imposes a positivity constraint on the effective susceptibility defined as the ratio of magnetization magnitude over the geomagnetic field strength. In addition, a distance-based weighting function is used to make the algorithm applicable to joint data sets. To solve this positivity-constraint inversion problem efficiently, an appropriate optimization method must be chosen. We first use an interior-point method to incorporate the positivity constraint into the total objective function, and then minimize the objective function via a Gauss-Newton method due to the nonlinearity introduced by the positivity constraint and the amplitude data. To further improve the efficiency of the inversion algorithm, we use a conjugate gradient method to carry out the fast matrix-vector multiplication during the minimization. To verify the utility of the proposed method, we invert the synthetic and field data using three inversion methods, including the joint inversion of surface and borehole three-component magnetic data, the inversion of surface magnetic amplitude data, and the proposed joint

  11. The range of motion of the metacarpo-phalangeal joint of the thumb and its relationship to injury.

    PubMed

    Shaw, S J; Morris, M A

    1992-04-01

    A wide variation in the range of flexion of the metacarpo-phalangeal joint of the thumb in normal individuals is described. Patients with a poor range of flexion at this joint have a significantly higher incidence of indirect soft-tissue injury to the joint.

  12. Case Series of First Metatarsophalangeal Joint Injuries in Division 1 College Athletes

    PubMed Central

    Faltus, John; Mullenix, Kerry; Moorman, Claude T.; Beatty, Kyle; Easley, Mark E.

    2014-01-01

    Context: Injuries of the first metatarsophalangeal (hallux MP) joint can be debilitating in the athletic population. Turf toe and plantar plate injuries are typically diagnosed similarly. However, variance in injury mechanism as well as compromised integrity of soft tissue and ligamentous structures make it difficult to accurately diagnose specific hallux MP injuries. Recent literature has supported the use of both radiographic imaging and the Lachman test as reliable indicators of joint instability in the presence of hallux MP injuries. To date, research supporting specific rehabilitation interventions and return-to-play decision making for hallux MP injuries has been limited to case studies and suggested guidelines from literature reviews. There is limited evidence suggesting specific criteria for surgical and nonsurgical decision making in conjunction with rehabilitation progressions to return an athlete to sport when managing hallux MP injuries. Evidence Acquisition: A literature search was performed using Medline, PubMed, and Google Scholar to find and review articles from 1970 to 2013 that addressed the basic anatomy of the plantar plate, injuries to this anatomical structure, and the evaluation, diagnosis, surgical and nonsurgical management, and rehabilitation of these injuries, specifically in the athletic population. Medical information for each case was gathered from electronic medical records from the individual athletes cited in this case series, which included imaging reports, rehabilitation documentation, and both evaluation and surgical reports. No statistical analysis was used. Study Design: Case series. Level of Evidence: Level 4. Results: Treatment plans for each case varied depending on surgical and nonsurgical intervention and rehabilitation outcomes. However, each athlete was able to return to sports-specific activities. Conclusion: Successful outcomes for hallux MP injuries are contingent on thorough evaluation, appropriate clinical decision

  13. Alternate bearing surfaces in total joint arthroplasty: biologic considerations.

    PubMed

    Archibeck, M J; Jacobs, J J; Black, J

    2000-10-01

    The problem of periprosthetic osteolysis is currently the major limiting factor in joint arthroplasty longevity. Because this process has been shown to be primarily a biologic response to wear particles, corrosion products, or both, efforts to reduce particle generation are being undertaken. These efforts include the development of modified polyethylene and alternative articulating surfaces. These alternate bearing surfaces currently include ceramic-on-polyethylene, ceramic-on-ceramic, and metal-on-metal. Although these alternate bearings diminish or eliminate the generation of polyethylene particles, ceramic and metal particles are produced. The purpose of the current review is to discuss the literature that addresses the biologic response to these particles, locally and systemically.

  14. Injury tolerance and moment response of the knee joint to combined valgus bending and shear loading.

    PubMed

    Bose, Dipan; Bhalla, Kavi S; Untaroiu, Costin D; Ivarsson, B Johan; Crandall, Jeff R; Hurwitz, Shepard

    2008-06-01

    Valgus bending and shearing of the knee have been identified as primary mechanisms of injuries in a lateral loading environment applicable to pedestrian-car collisions. Previous studies have reported on the structural response of the knee joint to pure valgus bending and lateral shearing, as well as the estimated injury thresholds for the knee bending angle and shear displacement based on experimental tests. However, epidemiological studies indicate that most knee injuries are due to the combined effects of bending and shear loading. Therefore, characterization of knee stiffness for combined loading and the associated injury tolerances is necessary for developing vehicle countermeasures to mitigate pedestrian injuries. Isolated knee joint specimens (n=40) from postmortem human subjects were tested in valgus bending at a loading rate representative of a pedestrian-car impact. The effect of lateral shear force combined with the bending moment on the stiffness response and the injury tolerances of the knee was concurrently evaluated. In addition to the knee moment-angle response, the bending angle and shear displacement corresponding to the first instance of primary ligament failure were determined in each test. The failure displacements were subsequently used to estimate an injury threshold function based on a simplified analytical model of the knee. The validity of the determined injury threshold function was subsequently verified using a finite element model. Post-test necropsy of the knees indicated medial collateral ligament injury consistent with the clinical injuries observed in pedestrian victims. The moment-angle response in valgus bending was determined at quasistatic and dynamic loading rates and compared to previously published test data. The peak bending moment values scaled to an average adult male showed no significant change with variation in the superimposed shear load. An injury threshold function for the knee in terms of bending angle and shear

  15. Post-Traumatic Osteoarthritis in Mice Following Mechanical Injury to the Synovial Joint

    PubMed Central

    Rai, Muhammad Farooq; Duan, Xin; Quirk, James D.; Holguin, Nilsson; Schmidt, Eric J.; Chinzei, Nobuaki; Silva, Matthew J.; Sandell, Linda J.

    2017-01-01

    We investigated the spectrum of lesions characteristic of post-traumatic osteoarthritis (PTOA) across the knee joint in response to mechanical injury. We hypothesized that alteration in knee joint stability in mice reproduces molecular and structural features of PTOA that would suggest potential therapeutic targets in humans. The right knees of eight-week old male mice from two recombinant inbred lines (LGXSM-6 and LGXSM-33) were subjected to axial tibial compression. Three separate loading magnitudes were applied: 6N, 9N, and 12N. Left knees served as non-loaded controls. Mice were sacrificed at 5, 9, 14, 28, and 56 days post-loading and whole knee joint changes were assessed by histology, immunostaining, micro-CT, and magnetic resonance imaging. We observed that tibial compression disrupted joint stability by rupturing the anterior cruciate ligament (except for 6N) and instigated a cascade of temporal and topographical features of PTOA. These features included cartilage extracellular matrix loss without proteoglycan replacement, chondrocyte apoptosis at day 5, synovitis present at day 14, osteophytes, ectopic calcification, and meniscus pathology. These findings provide a plausible model and a whole-joint approach for how joint injury in humans leads to PTOA. Chondrocyte apoptosis, synovitis, and ectopic calcification appear to be targets for potential therapeutic intervention. PMID:28345597

  16. [UHMWPE - polyethylene for articulating surfaces of joint replacements].

    PubMed

    Pokorný, David; Sosna, Antonín; Šlouf, Miroslav; Fulín, Petr; Štefan, Jan; Landor, Ivan

    2016-01-01

    The introduction of artificial joint replacement constitutes a breakthrough method of treatment for severe joint disease for millions of people worldwide.Annual increase in the number of primary replacement and also increasing demands on the longevity of joint replacements are leading to increased demands on wear resistance of articular surface. Ultra-high molecular weight polyethylene (UHMWPE) is still most commonly used material for the production of articular surface. It was introduced into clinical practice in the 60s of the 20th century. Physical-chemical properties of UHMWPE are subject of many studies. These lead gradually to its improvement in terms of higher wear resistance while maintaining the stability against oxidative degradation.The main objective of this review is to summarize the basic properties of high-molecular weight polyethylene which are important for its use in orthopaedic practice and to explain the possibilities of its modification and sterilization. Knowledge of the latest trends about this material helps to orthopaedic surgeons get oriented in the issues and then to choose for their patients implants with the highest implant longevity.

  17. The effect of surface and season on playground injury rates.

    PubMed

    Branson, Lara Joan; Latter, John; Currie, Gillian R; Nettel-Aguirre, Alberto; Embree, Tania; Hagel, Brent Edward

    2012-11-01

    To examine the effect of season on playground surface injury rates. Injuries were identified through student incident report forms used in school districts in Calgary (Alberta) and the surrounding area. Playground surface exposure data were estimated based on school enrollment. A total of 539 injuries were reported during the 2007/2008 school year. Abrasions, bruises and inflammation were the most frequently reported injuries. The head, neck or face were most commonly injured. Injury rates per 1000 student days ranged between 0.018 (rubber crumb in spring) and 0.08 (poured-in-place and natural rock in the fall). Rubber crumb surfacing, compared with natural rock, had a significantly lower rate of injury in the spring, but no other season-surface comparisons were statistically significant. Rates of injury were similar for natural rock, poured-in-place, and crushed rock in the fall and winter. There was some evidence of a lower rate of injury on rubber crumb surfaces in the spring.

  18. The effect of surface and season on playground injury rates

    PubMed Central

    Branson, Lara Joan; Latter, John; Currie, Gillian R; Nettel-Aguirre, Alberto; Embree, Tania; Hagel, Brent Edward

    2012-01-01

    OBJECTIVE: To examine the effect of season on playground surface injury rates. METHODS: Injuries were identified through student incident report forms used in school districts in Calgary (Alberta) and the surrounding area. Playground surface exposure data were estimated based on school enrollment. RESULTS: A total of 539 injuries were reported during the 2007/2008 school year. Abrasions, bruises and inflammation were the most frequently reported injuries. The head, neck or face were most commonly injured. Injury rates per 1000 student days ranged between 0.018 (rubber crumb in spring) and 0.08 (poured-in-place and natural rock in the fall). Rubber crumb surfacing, compared with natural rock, had a significantly lower rate of injury in the spring, but no other season-surface comparisons were statistically significant. CONCLUSIONS: Rates of injury were similar for natural rock, poured-in-place, and crushed rock in the fall and winter. There was some evidence of a lower rate of injury on rubber crumb surfaces in the spring. PMID:24179416

  19. The Effect of Surface Irregularities on Wing Drag. II - Lap Joints. 2; Lap Joints

    NASA Technical Reports Server (NTRS)

    Hood, Manley J.

    1938-01-01

    Tests have been made in the NACA 8-foot high-speed wind tunnel of the drag caused by four types of lap joint. The tests were made on an airfoil of NACA 23012 section and 5-foot chord and covered in a range of speeds from 80 to 500 miles per hour and lift coefficients from 0 to 0.30. The increases in profile drag caused by representative arrangements of laps varied from 4 to 9%. When there were protruding rivet heads on the surface, the addition of laps increased the drag only slightly. Laps on the forward part of a wing increased the drag considerably more than those farther back.

  20. [Value of magnetic resonance imaging in the diagnosis of sequels of shoulder joint injuries].

    PubMed

    Murashina, I V; Egorova, E A

    2011-01-01

    The paper presents the results of examining 45 persons with sequels of shoulder joint injuries, by applying magnetic resonance imaging (MRI) (100%) and arthroscopy (95.6%). The data of arthroscopy were compared with those of MRI; thereafter the sensitivity, specificity, and accuracy of MRI were calculated. The findings suggested that there was no statistically significant difference in the capacities of the two comparable techniques MRI and arthroscopy to diagnose labral tears with degenerative changes, synovitis, bursitis and tendinitis (McNemar's test; p > 0.05). The capacities of MRI are greater than those of arthroscopy only to detect the structural disintegrity of the joint shoulder.

  1. Acromioclavicular joint injuries in National Collegiate Athletic Association football: data from the 2004-2005 through 2008-2009 National Collegiate Athletic Association Injury Surveillance System.

    PubMed

    Dragoo, Jason L; Braun, Hillary J; Bartlinski, Stephen E; Harris, Alex H S

    2012-09-01

    Injuries to the shoulder are common in collegiate football, and injuries to the acromioclavicular (AC) joint have previously accounted for up to 41% of all shoulder injuries. To determine the incidence and epidemiology of injury to the AC joint in National Collegiate Athletic Association (NCAA) football athletes. Descriptive epidemiology study. The NCAA Injury Surveillance System (ISS) men's football database was reviewed from the 2004-2009 playing seasons. The exposure data set from the same years was reviewed for the purposes of computing rates of injury per athlete exposure (AE). The injury rate (number of injuries divided by number of AEs) was computed per 10,000 AEs for competition and practice exposures. Ninety-five percent confidence intervals (95% CIs) for the incidence rates were calculated using assumptions of a Poisson distribution. According to the estimates made by the NCAA ISS, a total of 748 injuries to the AC joint occurred in NCAA football players during 2,222,155 AEs, accounting for 4.49% of all injuries sustained during this 5-year surveillance period. The overall rate of injury was 3.34 per 10,000 AEs (95% CI, 3.10-3.59). Players were 11.68 (95% CI, 10.11-13.49) times more likely to sustain an injury in games than practices. Partial sprains (types I or II) accounted for 96.4% of injuries, while complete sprains (≥type III) accounted for the remaining 3.6%. The average amount of time lost per injury was 11.61 days. Complete sprains resulted in a mean time loss of 31.9 days (95% CI, 24.4-39.6) while partial injuries resulted in 11.0 days lost (95% CI, 9.6-12.3). Overall, 2.41% of injuries underwent surgical intervention, with 22.2% of complete sprains and 1.7% of partial injuries resulting in surgery. Complete sprains of the AC joint were 13.5 (95% CI, 4.63-35.26) times more likely to result in surgical intervention than partial sprains. The majority of injuries (71.93%) resulted from contact with another player and 47.09% occurred while

  2. The Self-Injury Trauma (SIT) Scale: A Method for Quantifying Surface Tissue Damage Caused by Self-Injurious Behavior.

    ERIC Educational Resources Information Center

    Iwata, Brian A.; And Others

    1990-01-01

    A measure, the Self-Injury Trauma Scale, is described for classifying and quantifying surface tissue damage. The scale permits differentiation of self-injurious behavior according to topography, location of the injury on the body, type of injury, number of injuries, and estimate of severity. High interrater reliability has been found. (Author/DB)

  3. Relationship between serum biomarkers of cartilage and bone metabolism and joint injury in young Thoroughbred racehorses in training.

    PubMed

    Jackson, Brendan F; Reed, Suzanne R; Price, Joanna S; Verheyen, Kristien L P

    2015-08-01

    To compare serum concentrations of biomarkers of cartilage and bone metabolism between racehorses with a carpal or metacarpophalangeal or metatarsophalangeal (ie, fetlock) joint injury and matched uninjured control horses, determine changes in biomarker concentrations following joint injury, and establish the biomarkers' diagnostic test performance. 50 Thoroughbred racehorses with a carpal or fetlock joint injury and 50 matched uninjured horses (control horses). Serum concentrations of 2 cartilage synthesis biomarkers (carboxy-terminal propeptide of type II collagen [CPII] and chondroitin sulfate epitope 846 [CS846]), 2 cartilage degradation biomarkers (neoepitope generated by collagenase cleavage of type II collagen [C2C] and cross-linked carboxy-terminal telopeptide fragments of type II collagen [CTX-II]), and serum activity of a bone formation marker (bone-specific alkaline phosphatase [BAP]) were measured around the time of injury diagnosis and monthly thereafter for as long as possible. Injured horses as a group and horses specifically with fetlock joint injuries had significantly lower serum CPII concentrations and significantly higher serum BAP activities than matched control horses. Concentrations of CTX-II were decreased between 2 and 4 months following joint injury. Measurement of CPII concentration at baseline could distinguish between injured horses and control horses with a sensitivity of 82% and specificity of 50%. Although significant differences in specific biomarker concentrations between horses with carpal and fetlock joint injuries and matched control horses were identified, there was no convincing evidence of the suitability of these biomarkers as diagnostic or prognostic tools in a clinical setting.

  4. Effects of Equine Joint Injury on Boundary Lubrication of Articular Cartilage by Synovial Fluid: Role of Hyaluronan

    PubMed Central

    Antonacci, Jennifer M.; Schmidt, Tannin A.; Serventi, Lisa A.; Cai, Matthew Z.; Shu, YuYu L.; Schumacher, Barbara L.; McIlwraith, C. Wayne; Sah, Robert L.

    2012-01-01

    Objective To compare equine synovial fluid (eSF) from post-injury and control joints for (1) cartilage boundary lubrication function, (2) putative boundary lubricant molecules hyaluronan (HA), proteoglycan-4 (PRG4), and surface-active phospholipids (SAPL), (3) relationships between lubrication function and composition, and (4) lubrication restoration by addition of HA. Methods eSF from normal (NL), acute injury (AI), and chronic injury (CI) joints were analyzed for boundary lubrication of normal articular cartilage as kinetic friction coefficient (μkinetic). eSF were also analyzed for HA, PRG4, and SAPL concentrations and HA molecular weight (MW) distribution. The effect of addition of HA, of different concentrations and MW, to AI- and NL-eSF samples on μkinetic was determined. Results The μkinetic of AI-eSF (0.036) was higher (+39%) than that of NL-eSF (0.026). Compared to NL-eSF, AI-eSF had a lower HA concentration (−30%) of lower MW forms, higher PRG4 concentration (+83%), and higher SAPL concentration (+144%). CI-eSF had μkinetic, HA, PRG4, and SAPL characteristics intermediate to that of AI-eSF and NL-eSF. Regression analysis revealed that μkinetic decreased with increasing HA concentration in eSF. The friction-reducing properties of HA alone improved with increasing concentration and MW. Addition of high-MW HA (4,000kDa) to AI-eSF reduced μkinetic to a value near that of NL-eSF. Conclusion In the acute post-injury stage, eSF exhibits poor boundary lubrication properties as indicated by a high μkinetic. HA of diminished concentration and MW may be the basis for this, and adding HA to deficient eSF restored lubrication function. PMID:22605527

  5. Concomitant glenohumeral pathologies associated with acute and chronic grade III and grade V acromioclavicular joint injuries.

    PubMed

    Jensen, Gunnar; Millett, Peter J; Tahal, Dimitri S; Al Ibadi, Mireille; Lill, Helmut; Katthagen, Jan Christoph

    2017-08-01

    The purpose of this study was to identify the risk of concomitant glenohumeral pathologies with acromioclavicular joint injuries grade III and V. Patients who underwent arthroscopically-assisted stabilization of acromioclavicular joint injuries grade III or grade V between 01/2007 and 12/2015 were identified in the patient databases of two surgical centres. Gender, age at index surgery, grade of acromioclavicular joint injury (Rockwood III or Rockwood V), and duration between injury and index surgery (classified as acute or chronic) were of interest. Concomitant glenohumeral pathologies were noted and their treatment was classified as debridement or reconstructive procedure. A total of 376 patients (336 male, 40 female) were included. Mean age at time of arthroscopic acromioclavicular joint reconstruction surgery was 42.1 ± 14.0 years. Overall, 201 patients (53%) had one or more concomitant glenohumeral pathologies. Lesions of the biceps tendon complex and rotator cuff were the most common. Forty-five patients (12.0%) had concomitant glenohumeral pathologies that required an additional repair. The remaining 156 patients (41.5%) received a debridement of their concomitant pathologies. Rockwood grade V compared to Rockwood grade III (p = 0.013; odds ratio 1.7), and chronic compared to acute injury were significantly associated with having a concomitant glenohumeral pathology (p = 0.019; odds ratio 1.7). The probability of having a concomitant glenohumeral pathology was also significantly associated with increasing age (p < 0.0001). Concomitant glenohumeral pathologies were observed in 53% of surgically treated patients with an acute or chronic acromioclavicular joint injury of either grade III or V. Twenty-two percent of these patients with concomitant glenohumeral pathologies received an additional dedicated repair procedure. Although a significant difference in occurrence of concomitant glenohumeral pathologies was seen between Rockwood grades III and V

  6. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2014-10-01

    Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK) Table of Contents...Joint Injury and Subsequent Post-Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK... SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK) 1. INTRODUCTION: Post-traumatic arthritis (PTA) is a clinically important complication of

  7. Development of Intra-Articular Drug Delivery to Alter Progression of Arthritis Following Joint Injury

    DTIC Science & Technology

    2012-04-01

    Arthritis Following Joint Injury Steven A. Olson, M.D. W81XWH-10-1-0890 Duke University Durham, NC 27705 15 September 2011 - 14 March ...4 Appendices – Abstract accepted for presentation at ORASI ( Osteoarthritis Research Society International) meeting in...NC 2Department of Biomedical Engineering, Duke University, Durham, NC PURPOSE: Post-traumatic arthritis (PTA) is a form of osteoarthritis (OA

  8. Horizontal and Vertical Stabilization of Acute Unstable Acromioclavicular Joint Injuries Arthroscopy-Assisted

    PubMed Central

    Cisneros, Luis Natera; Sarasquete Reiriz, Juan; Besalduch, Marina; Petrica, Alexandru; Escolà, Ana; Rodriguez, Joaquim; Fallone, Jan Carlo

    2015-01-01

    We describe the technical aspects of an arthroscopy-assisted procedure indicated for the management of acute unstable acromioclavicular joint injuries, consisting of a synthetic augmentation of both the coracoclavicular and acromioclavicular ligaments, that anatomically reproduces the coracoclavicular biomechanics and offers fixation that keeps the torn ends of the ligaments facing one another, thus allowing healing of the native structures without the need for a second surgical procedure for metal hardware removal. PMID:26870653

  9. Acromioclavicular joint dislocations: radiological correlation between Rockwood classification system and injury patterns in human cadaver species.

    PubMed

    Eschler, Anica; Rösler, Klaus; Rotter, Robert; Gradl, Georg; Mittlmeier, Thomas; Gierer, Philip

    2014-09-01

    The classification system of Rockwood and Young is a commonly used classification for acromioclavicular joint separations subdividing types I-VI. This classification hypothesizes specific lesions to anatomical structures (acromioclavicular and coracoclavicular ligaments, capsule, attached muscles) leading to the injury. In recent literature, our understanding for anatomical correlates leading to the radiological-based Rockwood classification is questioned. The goal of this experimental-based investigation was to approve the correlation between the anatomical injury pattern and the Rockwood classification. In four human cadavers (seven shoulders), the acromioclavicular and coracoclavicular ligaments were transected stepwise. Radiological correlates were recorded (Zanca view) with 15-kg longitudinal tension applied at the wrist. The resulting acromio- and coracoclavicular distances were measured. Radiographs after acromioclavicular ligament transection showed joint space enlargement (8.6 ± 0.3 vs. 3.1 ± 0.5 mm, p < 0.05) and no significant change in coracoclavicular distance (10.4 ± 0.9 vs. 10.0 ± 0.8 mm). According to the Rockwood classification only type I and II lesions occurred. After additional coracoclavicular ligament cut, the acromioclavicular joint space width increased to 16.7 ± 2.7 vs. 8.6 ± 0.3 mm, p < 0.05. The mean coracoclavicular distance increased to 20.6 ± 2.1 mm resulting in type III-V lesions concerning the Rockwood classification. Trauma with intact coracoclavicular ligaments did not result in acromioclavicular joint lesions higher than Rockwood type I and II. The clinical consequence for reconstruction of low-grade injuries might be a solely surgical approach for the acromioclavicular ligaments or conservative treatment. High-grade injuries were always based on additional structural damage to the coracoclavicular ligaments. Rockwood type V lesions occurred while muscle attachments were intact.

  10. Rules to limp by: joint compensation conserves limb function after peripheral nerve injury.

    PubMed

    Bauman, Jay M; Chang, Young-Hui

    2013-10-23

    Locomotion persists across all manner of internal and external perturbations. The objective of this study was to identify locomotor compensation strategies in rodent models of peripheral nerve injury. We found that hip-to-toe limb length and limb angle was preferentially preserved over individual joint angles after permanent denervation of rat ankle extensor muscles. These findings promote further enquiry into the significance of limb-level function for neuromechanical control of legged locomotion.

  11. Injury of superficial radial nerve on the wrist joint induced by intravenous injection.

    PubMed

    Sawaizumi, Takuya; Sakamoto, Atsuhiro; Ito, Hiromoto

    2003-08-01

    Eleven cases of injury of the superficial radial nerve on the wrist joint, caused by intravenous injection of a needle. Paralysis occurred immediately after injection of a needle into the cephalic vein of the wrist joint, which was immediately recognized by the patients themselves. Six patients who had only sensory disturbance without causalgia were subjected to follow-up observation; 5 patients with causalgia were administered with steroid infiltration injection 3 to 5 times. Of the latter 5 patients, one patient underwent surgery because the steroid infiltration injection showed no effects. Four patients (36.4%) completely recovered within three months, while 7 patients (63.6%) continued to show nervous symptoms. We concluded that intravenous injection of a needle should be performed at the wrist joint only when it is inevitable.

  12. How joint torques affect hamstring injury risk in sprinting swing-stance transition.

    PubMed

    Sun, Yuliang; Wei, Shutao; Zhong, Yunjian; Fu, Weijie; Li, Li; Liu, Yu

    2015-02-01

    The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases.

  13. How Joint Torques Affect Hamstring Injury Risk in Sprinting Swing–Stance Transition

    PubMed Central

    SUN, YULIANG; WEI, SHUTAO; ZHONG, YUNJIAN; FU, WEIJIE; LI, LI; LIU, YU

    2015-01-01

    ABSTRACT Purpose The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Methods Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. Results During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. Conclusions During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases. PMID:24911288

  14. Military Exercises, Knee and Ankle Joint Position Sense, and Injury in Male Conscripts: A Pilot Study

    PubMed Central

    Mohammadi, Farshid; Azma, Kamran; Naseh, Iman; Emadifard, Reza; Etemadi, Yasaman

    2013-01-01

    Context: The high incidence of lower limb injuries associated with physical exercises in military conscripts suggests that fatigue may be a risk factor for injuries. Researchers have hypothesized that lower limb injuries may be related to altered ankle and knee joint position sense (JPS) due to fatigue. Objective: To evaluate if military exercises could alter JPS and to examine the possible relation of JPS to future lower extremity injuries in military service. Design: Cohort study. Setting: Laboratory. Patients or Other Participants: A total of 50 male conscripts (age = 21.4 ± 2.3 years, height = 174.5 ± 6.4 cm, mass = 73.1 ± 6.3 kg) from a unique military base were recruited randomly. Main Outcome Measure(s): Participants performed 8 weeks of physical activities at the beginning of a military course. In the first part of the study, we instructed participants to recognize predetermined positions before and after military exercises so we could examine the effects of military exercise on JPS. The averages of the absolute error and the variable error of 3 trials were recorded. We collected data on the frequency of lower extremity injuries over 8 weeks. Next, the participants were divided into 2 groups: injured and uninjured. Separate 2 × 2 × 2 (group-by-time-by-joint) mixed-model analyses of variance were used to determine main effects and interactions of these factors for each JPS measure. In the second part of the study, we examined whether the effects of fatigue on JPS were related to the development of injury during an 8-week training program. We calculated Hedges effect sizes for JPS changes postexercise in each group and compared change scores between groups. Results: We found group-by-time interactions for all JPS variables (F range = 2.86–4.05, P < .01). All participants showed increases in JPS errors postexercise (P < .01), but the injured group had greater changes for all the variables (P < .01). Conclusions: Military conscripts who sustained lower

  15. Degenerative changes of the sacroiliac auricular joint surface-validation of influential factors.

    PubMed

    Nishi, Keita; Saiki, Kazunobu; Imamura, Takeshi; Okamoto, Keishi; Wakebe, Tetsuaki; Ogami, Keiko; Hasegawa, Takashi; Moriuchi, Takefumi; Sakamoto, Junya; Manabe, Yoshitaka; Tsurumoto, Toshiyuki

    2016-06-24

    The purpose of this study was to clarify the relevance of degenerative changes in the sacroiliac joint (SIJ) and the joints in the lower limb and lumbar spine using age estimation methods. We also examined the shape of the auricular surface to determine the effect of degenerative changes on each joint. A total of 200 iliac auricular surfaces from 100 Japanese male skeletons were examined macroscopically in accordance with conventional methods of age estimation. From the obtained estimated age, we calculated the deflection values, which represented the degree of degenerative changes of the joints. For comparison, we used osteophyte score data of the hip, knee, and zygapophyseal joints in lumbar spines from previous studies which had used the same bone specimens. As a quantitative indicator of auricular surface morphology, we defined the constriction ratio (CR) of the auricular surface and compared the CR values obtained with various measured values. Degenerative changes in the SIJ were positively correlated with those in both the hip joint and zygapophyseal joint, but a correlation with knee joints was found only on the left side. In skeletons from individuals aged ≥60 years as time of death, the CR was significantly different between the group with high scores and those with low scores in both the hip and sacroiliac joints. It has been suggested that degenerative changes in SIJs interact with those in the hip joint and zygapophyseal joint. In addition, the shape of the auricular surface may also be a relevant factor for degenerative changes in these joints.

  16. Development of an Arthroscopic Joint Capsule Injury Model in the Canine Shoulder

    PubMed Central

    Kovacevic, David; Baker, Andrew R.; Staugaitis, Susan M.; Kim, Myung-Sun; Ricchetti, Eric T.; Derwin, Kathleen A.

    2016-01-01

    Background The natural history of rotator cuff tears can be unfavorable as patients develop fatty infiltration and muscle atrophy that is often associated with a loss of muscle strength and shoulder function. To facilitate study of possible biologic mechanisms involved in early degenerative changes to rotator cuff muscle and tendon tissues, the objective of this study was to develop a joint capsule injury model in the canine shoulder using arthroscopy. Methods Arthroscopic surgical methods for performing a posterior joint capsulectomy in the canine shoulder were first defined in cadavers. Subsequently, one canine subject underwent bilateral shoulder joint capsulectomy using arthroscopy, arthroscopic surveillance at 2, 4 and 8 weeks, and gross and histologic examination of the joint at 10 weeks. Results The canine subject was weight-bearing within eight hours after index and follow-up surgeries and had no significant soft tissue swelling of the shoulder girdle or gross lameness. Chronic synovitis and macroscopic and microscopic evidence of pathologic changes to the rotator cuff bony insertions, tendons, myotendinous junctions and muscles were observed. Conclusions This study demonstrates feasibility and proof-of-concept for a joint capsule injury model in the canine shoulder. Future work is needed to define the observed pathologic changes and their role in the progression of rotator cuff disease. Ultimately, better understanding of the biologic mechanisms of early progression of rotator cuff disease may lead to clinical interventions to halt or slow this process and avoid the more advanced and often irreversible conditions of large tendon tears with muscle fatty atrophy. PMID:26808837

  17. Temporomandibular joint injury potential imposed by the low-velocity extension-flexion maneuver.

    PubMed

    Howard, R P; Hatsell, C P; Guzman, H M

    1995-03-01

    It has been proposed that significant temporomandibular joint injury can occur as a result of rapid extension-flexion motion of the neck (whip-lash). This motion, which is experienced by passengers in vehicles that undergo rear-end collisions, has been described as causing rapid protrusion and opening of the mandible. It has been speculated that this relative motion between the mandible and the cranium produces forces at the temporomandibular joint (TMJ) that injure the articular elements. The objective of this study was to measure these forces by an experimental method. Accelerometer sensor and high-speed cinematographic data were obtained from the kinematic responses of live human test subjects positioned as occupants in motor vehicles that underwent staged low-velocity rear-end collisions. Linear and moment forces generated at the TMJs were obtained from the resultant acceleration pulse at the craniomandibular complex, estimation of the mass properties of the mandible and its appended soft tissues, and the application of Newton's Second Law of motion. The maximum linear forces generated at the TMJ in a rear-end collision resulting in a velocity change of the test subject of 8 km/h (5 mph) were in the 7 to 10 N (1.6 to 2.2 lb) range. Moment forces at the joint peaked briefly at 0.55 N.m (4.81 lb-in). These force magnitudes generated at the TMJ constitute a minor fraction of the forces experienced at the joint during normal physiologic function. It is a conclusion of this study that injuries to the TMJ attributed to low-velocity "whiplash" cannot be accounted for by the joint forces produced by this maneuver.

  18. [Isokinetic torque of quadriceps in patients with untreated anterior cruciate ligament injury of the knee joint].

    PubMed

    Ikeda, H

    1993-09-01

    In order to study the role of muscle strength in patients with untreated anterior cruciate ligament (ACL) injury of the knee joint, the torque of the quadriceps was isokinetically measured during concentric contraction (CC) and passive eccentric contraction (PEC). The results were compared with those in normal individuals and sports players. Ninety patients with untreated ACL injury were subjected for the study. There were 50 men and 40 women. The normal group consisted of 20 students and the sports player group consisted of 20 soccer players. The peak torque and the torque at 30 degrees flexion of the quadriceps were isokinetically measured during CC and PEC by using a BIODEX machine. In patients with ACL injury, the peak torque was smaller in the injured side as compared with the uninjured side. At the same angle velocity, decrease of PEC in the injured side was larger than that of CC. These results were compared with the normal group and the sports player group. There was significant difference in the peak torque per body weight among each groups. But, the torque per body weight at 30 degrees flexion was almost consistent in these three groups. A considerable quadriceps atrophy occurs following ACL injury. In our experience, patients with functional absence of ACL are much more difficult to return to vigorous sports which require explosive eccentric contraction than to return to endurance sports which require repetitive concentric contractile efforts of the quadriceps. In the present study, decrease of the passive eccentric contraction in the injured side was more pronounced than that of the concentric contraction. From these results, the significantly decreased passive eccentric torque in the patients with untreated ACL injury can be a factor to cause instability of the knee joint in active daily life as well as in sports activities.

  19. Impact of joint theater trauma system initiatives on battlefield injury outcomes.

    PubMed

    Eastridge, Brian J; Costanzo, George; Jenkins, Donald; Spott, Mary Ann; Wade, Charles; Greydanus, Dominique; Flaherty, Stephen; Rappold, Joseph; Dunne, James; Holcomb, John B; Blackbourne, Lorne H

    2009-12-01

    The US military forces developed and implemented the Joint Theater Trauma System (JTTS) and Joint Theater Trauma Registry (JTTR) using US civilian trauma system models with the intent of improving outcomes after battlefield injury. The purpose of this analysis was to elaborate the impact of the JTTS. To quantify these achievements, the JTTR captured mechanism, acute physiology, diagnostic, therapeutic, and outcome data on 23,250 injured patients admitted to deployed US military treatment facilities from July 2003 through July 2008 for analysis. Comparative analysis to civilian trauma systems was done using the National Trauma Data Bank (NTDB). In contrast to civilian trauma systems with an 11.1% rate of penetrating injury, 68.3% of battlefield wounds were by penetrating mechanism. In the analyzed cohort, 23.3% of all patients had an Injury Severe Score (ISS) > or = 16, which is similar to the civilian rate of 22.4%. In the military injury population, 66% of injuries were combat-related. In addition, in the military injury group, 21.8% had metabolic evidence of shock with a base deficit > or = 5, 29.8% of patients required blood transfusion, and 6.4% of the total population of combat casualties required massive transfusion (>10 U red blood cells/24 hours). With this complex and severely injured population of battlefield injuries, the JTTS elements were used to recognize and remedy more than 60 trauma system issues requiring leadership and advocacy, education, research, and alterations in clinical care. Of particular importance to the trauma system was the implementation and tracking of performance improvement indicators and the dissemination of 27 evidence-based clinical practice guidelines (CPGs). In particular, the damage control resuscitation guideline was associated with a decrease in mortality in the massively transfused from 32% pre-CPG to 21% post-CPG. As evidence of the effectiveness of the JTTS, a mortality rate of 5.2% after battlefield hospital admission

  20. A joint econometric analysis of seat belt use and crash-related injury severity.

    PubMed

    Eluru, Naveen; Bhat, Chandra R

    2007-09-01

    This paper formulates a comprehensive econometric structure that recognizes two important issues in crash-related injury severity analysis. First, the impact of a factor on injury severity may be moderated by various observed and unobserved variables specific to an individual or to a crash. Second, seat belt use is likely to be endogenous to injury severity. That is, it is possible that intrinsically unsafe drivers do not wear seat belts and are the ones likely to be involved in high injury severity crashes because of their unsafe driving habits. The preceding issues are considered in the current research effort through the development of a comprehensive model of seat belt use and injury severity that takes the form of a joint correlated random coefficients binary-ordered response system. To our knowledge, this is the first instance of such a model formulation and application not only in the safety analysis literature, but in the econometrics literature in general. The empirical analysis is based on the 2003 General Estimates System (GES) data base. Several types of variables are considered to explain seat belt use and injury severity levels, including driver characteristics, vehicle characteristics, roadway design attributes, environmental factors, and crash characteristics. The results, in addition to confirming the effects of various explanatory variables, also highlight the importance of (a) considering the moderating effects of unobserved individual/crash-related factors on the determinants of injury severity and (b) seat belt use endogeneity. From a policy standpoint, the results suggest that seat belt non-users, when apprehended in the act, should perhaps be subjected to both a fine (to increase the chances that they wear seat belts) as well as mandatory enrollment in a defensive driving course (to attempt to change their aggressive driving behaviors).

  1. In-vitro and in-vivo imaging of MMP activity in cartilage and joint injury.

    PubMed

    Fukui, Tomoaki; Tenborg, Elizabeth; Yik, Jasper H N; Haudenschild, Dominik R

    2015-05-08

    Non-destructive detection of cartilage-degrading activities represents an advance in osteoarthritis (OA) research, with implications in studies of OA pathogenesis, progression, and intervention strategies. Matrix metalloproteinases (MMPs) are principal cartilage degrading enzymes that contribute to OA pathogenesis. MMPSense750 is an in-vivo fluorimetric imaging probe with the potential to continuously and non-invasively trace real-time MMP activities, but its use in OA-related research has not been reported. Our objective is to detect and characterize the early degradation activities shortly after cartilage or joint injury with MMPSense750. We determined the appropriate concentration, assay time, and linear range using various concentrations of recombinant MMPs as standards. We then quantified MMP activity from cartilage explants subjected to either mechanical injury or inflammatory cytokine treatment in-vitro. Finally, we performed in-vivo MMP imaging of a mouse model of post-traumatic OA. Our in-vitro results showed that the optimal assay time was highly dependent on the MMP enzyme. In cartilage explant culture media, mechanical impact or cytokine treatment increased MMP activity. Injured knees of mice showed significantly higher fluorescent signal than uninjured knees. We conclude that MMPSense750 detects human MMP activities and can be used for in-vitro study with cartilage, as well as in-vivo studies of knee injury, and can offering real-time insight into the degradative processes that occurring within the joint before structural changes become evident radiographically.

  2. Anatomical study of the ligamentous attachments and articular surfaces of the trapeziometacarpal joint. Consequences on surgical management of its osteoarthrosis.

    PubMed

    Maes-Clavier, C; Bellemère, P; Gabrion, A; David, E; Rotari, V; Havet, E

    2014-04-01

    In the goal to optimize conservative surgical techniques of the trapeziometacarpal joint in cases of moderate osteoarthritis, we have defined the relationships between the ligamentous attachments and the articular surfaces onto the trapezium and the first metacarpal bone on the one hand, and the dorsovolar and the transverse diameters of the articular surfaces on the other hand. Thirty-six trapeziometacarpal joints (from 18 fresh cadavers) were studied. They were separated into two groups depending on the macroscopic assessment of chondral disease. Group A included stages I to III (no osteoarthritis or moderate osteoarthritis), group B included stages IV (major cartilage destruction). The dorsovolar and transverse sizes of the articular surfaces were measured. Dorsoradial ligament (DRL), posterior oblique ligament (POL), intermetacarpal ligament (IML), ulnar collateral ligament (UCL) and anterior oblique ligament (AOL) were dissected and the distance between their attachments and the articular surfaces were measured. Group A included 17 joints (71% males) and group B included 19 joints (95% females). For the first metacarpal bone, the average ratio between the dorsovolar diameter and the transverse diameter of metacarpal articular surfaces was significantly higher in group B and the average distance between the ligamentous attachments and the articular surface was more than two millimeters, except for the DRL in group B. For the trapezium, only the posterior ligaments (DRL and POL) of group A were inserted at a mean distance more than two millimeters from the articular surfaces. Dorsovolar length of the metacarpal articular surface was higher for osteoarthritis cases. This difference can be explained by the existence of a palmar osteophyte that was always found in stage IV. Describing a map of the ligamentous attachment distance from the articular surface could help surgeons to avoid the ligamentous injury during minimal osteochondral resection.

  3. Exploiting endogenous fibrocartilage stem cells to regenerate cartilage and repair joint injury

    PubMed Central

    Embree, Mildred C.; Chen, Mo; Pylawka, Serhiy; Kong, Danielle; Iwaoka, George M.; Kalajzic, Ivo; Yao, Hai; Shi, Chancheng; Sun, Dongming; Sheu, Tzong-Jen; Koslovsky, David A.; Koch, Alia; Mao, Jeremy J.

    2016-01-01

    Tissue regeneration using stem cell-based transplantation faces many hurdles. Alternatively, therapeutically exploiting endogenous stem cells to regenerate injured or diseased tissue may circumvent these challenges. Here we show resident fibrocartilage stem cells (FCSCs) can be used to regenerate and repair cartilage. We identify FCSCs residing within the superficial zone niche in the temporomandibular joint (TMJ) condyle. A single FCSC spontaneously generates a cartilage anlage, remodels into bone and organizes a haematopoietic microenvironment. Wnt signals deplete the reservoir of FCSCs and cause cartilage degeneration. We also show that intra-articular treatment with the Wnt inhibitor sclerostin sustains the FCSC pool and regenerates cartilage in a TMJ injury model. We demonstrate the promise of exploiting resident FCSCs as a regenerative therapeutic strategy to substitute cell transplantation that could be beneficial for patients suffering from fibrocartilage injury and disease. These data prompt the examination of utilizing this strategy for other musculoskeletal tissues. PMID:27721375

  4. ISAKOS upper extremity committee consensus statement on the need for diversification of the Rockwood classification for acromioclavicular joint injuries.

    PubMed

    Beitzel, Knut; Mazzocca, Augustus D; Bak, Klaus; Itoi, Eiji; Kibler, William B; Mirzayan, Raffy; Imhoff, Andreas B; Calvo, Emilio; Arce, Guillermo; Shea, Kevin

    2014-02-01

    Optimal treatment for the unstable acromioclavicular (AC) joint remains a highly debated topic in the field of orthopaedic medicine. In particular, no consensus exists regarding treatment of grade III injuries, which are classified according to the Rockwood classification by disruption of both the coracoclavicular and AC ligaments. The ISAKOS Upper Extremity Committee has provided a more specific classification of shoulder pathologies to enhance the knowledge on and clinical approach to these injuries. We suggest the addition of grade IIIA and grade IIIB injuries to a modified Rockwood classification. Grade IIIA injuries would be defined by a stable AC joint without overriding of the clavicle on the cross-body adduction view and without significant scapular dysfunction. The unstable grade IIIB injury would be further defined by therapy-resistant scapular dysfunction and an overriding clavicle on the cross-body adduction view.

  5. THE EFFECT OF CONSERVATIVELY TREATED ACL INJURY ON KNEE JOINT POSITION Sense

    PubMed Central

    Herrington, Lee

    2016-01-01

    ABSTRACT Background Proprioception is critical for effective movement patterns. However, methods of proprioceptive measurement in previous research have been inconsistent and lacking in reliability statistics making it applications to clinical practice difficult. Researchers have suggested that damage to the anterior cruciate ligament (ACL) can alter proprioceptive ability due to a loss of functioning mechanoreceptors. The majority of patients opt for reconstructive surgery following this injury. However, some patients chose conservative rehabilitation options rather than surgical intervention. Purpose The purpose of this study was to determine the effect of ACL deficiency on knee joint position sense following conservative, non-operative treatment and return to physical activity. A secondary purpose was to report the reliability and measurement error of the technique used to measure joint position sense, (JPS) and comment on the clinical utility of this measurement. Study Design Observational study design using a cross-section of ACL deficient patients and matched uninjured controls. Methods Twenty active conservatively treated ACL deficient patients who had returned to physical activity and twenty active matched controls were included in the study. Knee joint position sense was measured using a seated passive-active reproductive angle technique. The average absolute angle of error score, between 10 °-30 ° of knee flexion was determined. This error score was derived from the difference between the target and repositioning angle. Results The ACL deficient patients had a greater error score (7.9 °±3.6) and hence poorer static proprioception ability that both the contra-lateral leg (2.0 °±1.6; p = 0.0001) and the control group (2.6 °±0.9; p = 0.0001). The standard error of the mean (SEM) of this JPS technique was 0.5 ° and 0.2 ° and the minimum detectable change (MDC) was 1.3 ° and 0.4 ° on asymptomatic and symptomatic subjects

  6. [Kirschner wire fixation in three joints combined with bone anchor repair for treatment of acute perilunate injury ].

    PubMed

    Zhou, Yan; Liu, Shiqing; Yu, Ling; Liao, Qi; Huang, Tao; Zhao Qi; Zhang, Chun

    2014-09-01

    To investigate the effectiveness of Kirschner wire fixation in scapholunate joint, capitolunate joint, and lunotriquetral joint combined with bone anchor repair for the treatment of acute perilunate injury. Between January 2007 and January 2012, 35 cases of acute perilunate injury were treated. There were 30 males and 5 females with an average age of 45.5 years (range, 32-56 years). Fractures were caused by falling from height in 18 cases, by traffic accident in 11 cases, and by fall injury in 4 cases. The time from injury to operation was 2-6 days (mean, 3.4 days). There were 23 cases of trans-scaphoid perilunate dislocation, 10 cases of perilunate dislocation, and 2 cases of trans-triangular perilunate dislocation. Associated injuries included median nerve injury in 6 cases, radius styloid fracture in 8 cases, ulnar styloid fracture in 2 cases, and distal tibial fracture in 1 case. All the patients were treated by open reduction, Herbert screw fixation of scaphoid fractures, and Kirschner wire fixation in scapholunate joint, capitolunate joint, and lunotriquetral joint, and the intercarpal ligaments were repaired by Mitek bone anchor. Superficial wound infection occurred in 2 cases, and primary healing of incision obtained in others. Thirty-five patients were followed up 12-35 months (mean, 18 months). X-ray films showed fracture union in 21 cases of scaphoid fractures, and bone nonunion in 2 cases of scaphoid fractures. During the follow-up period, there was no avascular necrosis ofscaphoid or lunate. At last follow-up, the scapholunate angle, radiolunate angle, and wrist range of motion (ROM) in extension had no significant difference between affected and unaffected sides (P > 0.05). The wrist ROM in flexion and grip strength of affected side were not up to the levels of unaffected side (P < 0.05). According to the modified Mayo wrist scoring system, the score was 79.9 ± 10.7, which were excellent in 8 cases, good in 17 cases, fair in 7 cases, and poor in 3

  7. Targeting pro-inflammatory cytokines following joint injury: acute intra-articular inhibition of interleukin-1 following knee injury prevents post-traumatic arthritis

    PubMed Central

    2014-01-01

    Introduction Post-traumatic arthritis (PTA) is a progressive, degenerative response to joint injury, such as articular fracture. The pro-inflammatory cytokines, interleukin 1(IL-1) and tumor necrosis factor alpha (TNF-α), are acutely elevated following joint injury and remain elevated for prolonged periods post-injury. To investigate the role of local and systemic inflammation in the development of post-traumatic arthritis, we targeted both the initial acute local inflammatory response and a prolonged 4 week systemic inflammatory response by inhibiting IL-1 or TNF-α following articular fracture in the mouse knee. Methods Anti-cytokine agents, IL-1 receptor antagonist (IL-1Ra) or soluble TNF receptor II (sTNFRII), were administered either locally via an acute intra-articular injection or systemically for a prolonged 4 week period following articular fracture of the knee in C57BL/6 mice. The severity of arthritis was then assessed at 8 weeks post-injury in joint tissues via histology and micro computed tomography, and systemic and local biomarkers were assessed in serum and synovial fluid. Results Intra-articular inhibition of IL-1 significantly reduced cartilage degeneration, synovial inflammation, and did not alter bone morphology following articular fracture. However, systemic inhibition of IL-1, and local or systemic inhibition of TNF provided no benefit or conversely led to increased arthritic changes in the joint tissues. Conclusion These results show that intra-articular IL-1, rather than TNF-α, plays a critical role in the acute inflammatory phase of joint injury and can be inhibited locally to reduce post-traumatic arthritis following a closed articular fracture. Targeted local inhibition of IL-1 following joint injury may represent a novel treatment option for PTA. PMID:24964765

  8. Changes in Joint Contact Mechanics in a Large Quadrupedal Animal Model After Partial Meniscectomy and a Focal Cartilage Injury.

    PubMed

    Heckelsmiller, David J; James Rudert, M; Baer, Thomas E; Pedersen, Douglas R; Fredericks, Douglas C; Goetz, Jessica E

    2017-05-01

    Acute mechanical damage and the resulting joint contact abnormalities are central to the initiation and progression of post-traumatic osteoarthritis (PTOA). Study of PTOA is typically performed in vivo with replicate animals using artificially induced injury features. The goal of this work was to measure changes in a joint contact stress in the knee of a large quadruped after creation of a clinically realistic overload injury and a focal cartilage defect. Whole-joint overload was achieved by excising a 5-mm wedge of the anterior medial meniscus. Focal cartilage defects were created using a custom pneumatic impact gun specifically developed and mechanically characterized for this work. To evaluate the effect of these injuries on joint contact mechanics, Tekscan (Tekscan, Inc., South Boston, MA) measurements were obtained pre-operatively, postmeniscectomy, and postimpact (1.2-J) in a nonrandomized group of axially loaded cadaveric sheep knees. Postmeniscectomy, peak contact stress in the medial compartment is increased by 71% (p = 0.03) and contact area is decreased by 35% (p = 0.001); the center of pressure (CoP) shifted toward the cruciate ligaments in both the medial (p = 0.004) and lateral (p = 0.03) compartments. The creation of a cartilage defect did not significantly change any aspect of contact mechanics measured in the meniscectomized knee. This work characterizes the mechanical environment present in a quadrupedal animal knee joint after two methods to reproducibly induce joint injury features that lead to PTOA.

  9. Upper extremity interaction with a helicopter side airbag: injury criteria for dynamic hyperextension of the female elbow joint.

    PubMed

    Duma, Stefan M; Hansen, Gail A; Kennedy, Eric A; Rath, Amber L; McNally, Craig; Kemper, Andrew R; Smith, Eric P; Brolinson, P Gunnar; Stitzel, Joel D; Davis, Martin B; Bass, Cameron R; Brozoski, Frederick T; McEntire, B Joseph; Alem, Nabih M; Crowley, John S

    2004-11-01

    This paper describes a three part analysis to characterize the interaction between the female upper extremity and a helicopter cockpit side airbag system and to develop dynamic hyperextension injury criteria for the female elbow joint. Part I involved a series of 10 experiments with an original Army Black Hawk helicopter side airbag. A 5(th) percentile female Hybrid III instrumented upper extremity was used to demonstrate side airbag upper extremity loading. Two out of the 10 tests resulted in high elbow bending moments of 128 Nm and 144 Nm. Part II included dynamic hyperextension tests on 24 female cadaver elbow joints. The energy source was a drop tower utilizing a three-point bending configuration to apply elbow bending moments matching the previously conducted side airbag tests. Post-test necropsy showed that 16 of the 24 elbow joint tests resulted in injuries. Injury severity ranged from minor cartilage damage to more moderate joint dislocations and severe transverse fractures of the distal humerus. Peak elbow bending moments ranged from 42.4 Nm to 146.3 Nm. Peak bending moment proved to be a significant indicator of any elbow injury (p = 0.02) as well as elbow joint dislocation (p = 0.01). Logistic regression analyses were used to develop single and multiple variate injury risk functions. Using peak moment data for the entire test population, a 50% risk of obtaining any elbow injury was found at 56 Nm while a 50% risk of sustaining an elbow joint dislocation was found at 93 Nm for the female population. These results indicate that the peak elbow bending moments achieved in Part I are associated with a greater than 90% risk for elbow injury. Subsequently, the airbag was re-designed in an effort to mitigate this as well as the other upper extremity injury risks. Part III assessed the redesigned side airbag module to ensure injury risks had been reduced prior to implementing the new system. To facilitate this, 12 redesigned side airbag deployments were conducted

  10. [Operative treatment and curative effects of the deltoid ligament injuries of the ankle joint].

    PubMed

    Cong, Pei-Jun; Liu, Bai-Hong; Wang, Ji-Ping; Qiao, Yong-Ping

    2009-12-01

    To explore the operative methods and curative effects of the deltoid ligament injuries. From 2002 to 2008, all 61 patients with ankle fractures complicated with deltoid ligament injuries were treated with open reduction and firm internal fixation. Among the patients, 39 patients were male and 22 patients were female, ranging in age from 14 to 71 years, with an average of 41 years. During the operation, the deltoid ligament was reconstructed to restore the medial and lateral stability of ankle joint. All the patients were followed up ranged from 5 to 30 months, with an average of 17 months. Fifty-nine patients had incision healed at the first stage; 2 patients had superficial infections at lateral malleolus, and healed at the 3rd week after changing dressings. The incisions at the internal medial malleolus were all healed at the first stage. According to Qi evaluation criteria, 35 patients got an excellent result, 13 good and 13 fair. The deltoid ligament should be treated properly in the treatment of ankle joint fractures when open reduction and firm internal fixation were emphasized.

  11. The extent and risk of knee injuries in children aged 9-14 with Generalised Joint Hypermobility and knee joint hypermobility - the CHAMPS-study Denmark.

    PubMed

    Junge, Tina; Larsen, Lisbeth Runge; Juul-Kristensen, Birgit; Wedderkopp, Niels

    2015-06-12

    Generalised Joint Hypermobility (GJH) is suggested as an aetiological factor for knee injuries in adolescents and adults. It is presumed that GJH causes decreased joint stability, thereby increasing the risk of knee injuries during challenging situations like jumping and landing. The aim was to study the extent and risk of knee injuries in children with GJH and knee hypermobility. In total, 999 children (9-14 years) were tested twice during spring 2012 and 2013 with Beighton's Tests (BT) for hypermobility, a 0-9 scoring system. GJH was classified with cut-point ≥5/9 on both test rounds. On basis of weekly cell phone surveys of knee pain, children requiring clinical examination were seen. Traumatic and overuse knee injuries were registered by WHO ICD-10 diagnoses. Logistic regression and Poisson regression models with robust standard errors were used to examine the association between GJH and knee injuries, taking into account clustering on school class levels. Totally, 36 children were classified GJH on both test rounds. Overuse knee injuries were the most frequent injury type (86 %), mainly apophysitis for both groups (61 %), other than patella-femoral pain syndrome for the control group (13 %). For traumatic knee injuries, distortions and contusions were most frequent in both groups (51 % resp. 36 %), besides traumatic lesions of knee tendons and muscles for the control group (5 %). No significant association was found between overuse knee injuries and GJH with/without knee hypermobility (OR 0.69, p = 0.407 resp. OR 0.75, p = 0.576) or traumatic knee injuries and GJH with/without knee hypermobility (OR 1.56, p = 0.495 resp. OR 2.22, p = 0.231). Apophysitis, distortions and contusions were the most frequent knee injuries. Despite the relatively large study, the number of children with GJH and knee injuries was low, with no significant increased risk for knee injuries for this group. This questions whether GJH is a clinically relevant risk factor for knee

  12. Percutaneous Distraction Pinning for Metacarpophalangeal Joint Stabilization After Blast or Crush Injuries of the Hand.

    PubMed

    Langford, Matthew A; Cheung, Kevin; Li, Zhongyu

    2015-09-01

    Unstable, severely comminuted fractures of the metacarpophalangeal (MCP) joint are difficult to treat. Closed treatment and casting of these fractures often fail to maintain proper alignment and impede wound care where concomitant open injuries such as gunshot wounds are present. Conventional pinning or plating techniques are not feasible if extensive bone loss and comminution are present. A distraction pinning technique represents a potential alternative, but results with this approach, to our knowledge, have not been reported. The purposes of this study were (1) to evaluate the effectiveness (defined as osseous union and joint stability) of distraction pinning for comminuted fractures involving MCP joints after gunshot or crush injuries; (2) to report the short-term results in terms of pain and function in a small group of patients who underwent MCP distraction pinning; and (3) to evaluate complications and return to work status of these patients in the short term. We reviewed 10 patients with comminuted pilon-type fractures of the base of the proximal phalanx or metacarpal head treated with wire distraction fixation from 2005 and 2014. During that period, we used this technique to treat all patients whose fractures were deemed too comminuted for plating or pinning, and during that period, no other techniques (such as simple external fixation) were used for patients meeting those indications. The minimum followup was 6 months; eight of the 10 patients were accounted at a median of 10 months (range, 6-89 months). The median age was 47 years (range, 28-57 years), and seven of the eight were male. Kirschner wire fixation frames were removed 3.5 to 6 weeks after the index surgery when fracture consolidation was confirmed on radiography by the treating surgeon. Stability and range of motion of the MCP joint were assessed using physical examination, radiographs, and goniometer by the treating surgeon. Patients completed the Quick Disabilities of the Arm, Shoulder and

  13. Neuronal hyperexcitability in the dorsal horn after painful facet joint injury.

    PubMed

    Quinn, Kyle P; Dong, Ling; Golder, Francis J; Winkelstein, Beth A

    2010-11-01

    Excessive cervical facet capsular ligament stretch has been implicated as a cause of whiplash-associated disorders following rear-end impacts, but the pathophysiological mechanisms that produce chronic pain in these cases remain unclear. Using a rat model of C6-C7 cervical facet joint capsule stretch that produces sustained mechanical hyperalgesia, the presence of neuronal hyperexcitability was characterized 7 days after joint loading. Extracellular recordings of spinal dorsal horn neuronal activity between C6 and C8 (117 neurons) were obtained from anesthetized rats, with both painful and non-painful behavioral outcomes established by the magnitude of capsule stretch. The frequency of neuronal firing during noxious pinch (p<0.0182) and von Frey filaments applications (4-26g) to the forepaw was increased (p<0.0156) in the painful group compared to the non-painful and sham groups. In addition, the incidence and frequency of spontaneous and after discharge firing were greater in the painful group (p<0.0307) relative to sham. The proportion of cells in the deep laminae that responded as wide dynamic range neurons also was increased in the painful group relative to non-painful or sham groups (p<0.0348). These findings suggest that excessive facet capsule stretch, while not producing visible tearing, can produce functional plasticity of dorsal horn neuronal activity. The increase in neuronal firing across a range of stimulus magnitudes observed at day 7 post-injury provides the first direct evidence of neuronal modulation in the spinal cord following facet joint loading, and suggests that facet-mediated chronic pain following whiplash injury is driven, at least in part, by central sensitization. Copyright © 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  14. Biepicondylar fracture dislocation of the elbow joint concomitant with ulnar nerve injury

    PubMed Central

    Konya, M Nuri; Aslan, Ahmet; Sofu, Hakan; Yıldırım, Timur

    2013-01-01

    In this article, we present a case of humeral biepicondylar fracture dislocation concomitant with ulnar nerve injury in a seventeen year-old male patient. Physical examination of our patient in the emergency room revealed a painful, edematous and deformed-looking left elbow joint. Hypoesthesia of the little finger was also diagnosed on the left hand. Radiological assessment ended up with a posterior fracture dislocation of the elbow joint accompanied by intra-articular loose bodies. Open reduction-Internal fixation of the fracture dislocation and ulnar nerve exploration were performed under general anesthesia at the same session as surgical treatment of our patient. Physical therapy and rehabilitation protocol was implemented at the end of two weeks post-operatively. Union of the fracture lines, as well as the olecranon osteotomy site, was achieved at the end of four months post-operatively. Ulnar nerve function was fully restored without any sensory or motor loss. Range of motion at the elbow joint was 20-120 degrees at the latest follow-up. PMID:23610759

  15. Biepicondylar fracture dislocation of the elbow joint concomitant with ulnar nerve injury.

    PubMed

    Konya, M Nuri; Aslan, Ahmet; Sofu, Hakan; Yıldırım, Timur

    2013-04-18

    In this article, we present a case of humeral biepicondylar fracture dislocation concomitant with ulnar nerve injury in a seventeen year-old male patient. Physical examination of our patient in the emergency room revealed a painful, edematous and deformed-looking left elbow joint. Hypoesthesia of the little finger was also diagnosed on the left hand. Radiological assessment ended up with a posterior fracture dislocation of the elbow joint accompanied by intra-articular loose bodies. Open reduction-Internal fixation of the fracture dislocation and ulnar nerve exploration were performed under general anesthesia at the same session as surgical treatment of our patient. Physical therapy and rehabilitation protocol was implemented at the end of two weeks post-operatively. Union of the fracture lines, as well as the olecranon osteotomy site, was achieved at the end of four months post-operatively. Ulnar nerve function was fully restored without any sensory or motor loss. Range of motion at the elbow joint was 20-120 degrees at the latest follow-up.

  16. Surgical normalization of the shoulder joint in obstetric brachial plexus injury.

    PubMed

    Nath, Rahul K; Amrani, Abdelouahed; Melcher, Sonya E; Wentz, Melissa J; Paizi, Melia

    2010-10-01

    Obstetric brachial plexus injuries (OBPI) result in bony derangements that include posterior humeral head subluxation, glenoid retroversion, and joint incongruity. Often these deformities are accompanied by scapular hypoplasia, elevation, and rotation, which further exacerbate shoulder dysfunction. The purpose of the current study was to investigate the effects of triangle tilt surgery on glenohumeral joint anatomy in 100 OBPI patients. The triangle tilt surgery restores the distal acromioclavicular triangle from an abnormal superiorly angled position to a neutral position, thereby restoring normal glenohumeral anatomic relationships.Axial computed tomography and magnetic resonance images taken before and 12- to 38-months after surgery showed significant improvements in both posterior subluxation and glenoid version. Patients with complete posterior glenohumeral dislocation improved from 19% preoperatively, to 11% postoperatively. Glenoid shape was also improved, with 81% of patients classified as concave or flat after surgery compared with 53% before surgery.Triangle tilt surgery allows for both repositioning and remodeling of the glenohumeral joint. These anatomic improvements after triangle tilt surgery hold promise for improving shoulder function and quality of life for OBPI patients.

  17. In-vitro and in-vivo imaging of MMP activity in cartilage and joint injury

    SciTech Connect

    Fukui, Tomoaki; Tenborg, Elizabeth; Yik, Jasper H.N.; Haudenschild, Dominik R.

    2015-05-08

    Non-destructive detection of cartilage-degrading activities represents an advance in osteoarthritis (OA) research, with implications in studies of OA pathogenesis, progression, and intervention strategies. Matrix metalloproteinases (MMPs) are principal cartilage degrading enzymes that contribute to OA pathogenesis. MMPSense750 is an in-vivo fluorimetric imaging probe with the potential to continuously and non-invasively trace real-time MMP activities, but its use in OA-related research has not been reported. Our objective is to detect and characterize the early degradation activities shortly after cartilage or joint injury with MMPSense750. We determined the appropriate concentration, assay time, and linear range using various concentrations of recombinant MMPs as standards. We then quantified MMP activity from cartilage explants subjected to either mechanical injury or inflammatory cytokine treatment in-vitro. Finally, we performed in-vivo MMP imaging of a mouse model of post-traumatic OA. Our in-vitro results showed that the optimal assay time was highly dependent on the MMP enzyme. In cartilage explant culture media, mechanical impact or cytokine treatment increased MMP activity. Injured knees of mice showed significantly higher fluorescent signal than uninjured knees. We conclude that MMPSense750 detects human MMP activities and can be used for in-vitro study with cartilage, as well as in-vivo studies of knee injury, and can offering real-time insight into the degradative processes that occurring within the joint before structural changes become evident radiographically. - Highlights: • MMPSense750 is near-infrared fluorescent probe which can detect MMP activity. • MMPSense750 can detect human MMP-3, -9, and -13. • The reaction kinetics with MMPSense750 were different for the three MMPs. • MMPSense750 can visualized real time MMP activity in mouse injured knees. • MMPSense750 is convenient tool to evaluate real-time MMP activity non-invasively.

  18. Dietary fatty acid content regulates wound repair and the pathogenesis of osteoarthritis following joint injury.

    PubMed

    Wu, Chia-Lung; Jain, Deeptee; McNeill, Jenna N; Little, Dianne; Anderson, John A; Huebner, Janet L; Kraus, Virginia B; Rodriguiz, Ramona M; Wetsel, William C; Guilak, Farshid

    2015-11-01

    The mechanisms linking obesity and osteoarthritis (OA) are not fully understood and have been generally attributed to increased weight, rather than metabolic or inflammatory factors. Here, we examined the influence of fatty acids, adipokines, and body weight on OA following joint injury in an obese mouse model. Mice were fed high-fat diets rich in various fatty acids (FA) including saturated FAs (SFAs), ω-6 polyunsaturated FAs (PUFAs), and ω-3 PUFAs. OA was induced by destabilising the medial meniscus. Wound healing was evaluated using an ear punch. OA, synovitis and wound healing were determined histologically, while bone changes were measured using microCT. Activity levels and serum cytokines were measured at various time-points. Multivariate models were performed to elucidate the associations of dietary, metabolic and mechanical factors with OA and wound healing. Using weight-matched mice and multivariate models, we found that OA was significantly associated with dietary fatty acid content and serum adipokine levels, but not with body weight. Furthermore, spontaneous activity of the mice was independent of OA development. Small amounts of ω-3 PUFAs (8% by kcal) in a high-fat diet were sufficient to mitigate injury-induced OA, decreasing leptin and resistin levels. ω-3 PUFAs significantly enhanced wound repair, SFAs or ω-6 PUFAs independently increased OA severity, heterotopic ossification and scar tissue formation. Our results indicate that with obesity, dietary FA content regulates wound healing and OA severity following joint injury, independent of body weight, supporting the need for further studies of dietary FA supplements as a potential therapeutic approach for OA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. [Injuries to the superior ankle joint from the viewpoint of accident surgery].

    PubMed

    Zwipp, H

    1991-12-01

    The treatment of bony, osteochondral, and ligamentous injuries of the tibio-talar joint requires precise preoperative planning by radiological investigation. This is essential to a correct understanding of the underlying pathology and will allow a proper classification of the injury, which is the basis of treatment. Conventional radiography using anteroposterior and lateral X-rays with comparative views of the noninjured side and, if necessary, rotated spot views and tomography are of high value especially in osteochondral fractures of the talus. Intraoperative control images in both planes after osteosynthesis are mandatory. For evaluation of the postoperative course and severity of arthrosis formation, the classification system of Bargon has proved its worth. In addition, tomography of the tibio-talar joint in two planes is useful especially in tibial pilon fractures, some malleolar fractures, and peripheral talar fractures. In talar fracture dislocations with concomitant compartment syndrome an emergency CT scan can be helpful to determine the optimal surgical approach. In these cases a 3-D reconstruction also might be of assistance. If there is evidence of partial or total talar necrosis, magnetic resonance imaging can be extremely helpful. However, in most cases implants considerably limit the validity of the image obtained. Ultrasonography offers a noninvasive, reproducible, and very inexpensive alternative and should be performed in cases of chondral-osteochondral talar rim avulsions and juvenile osteochondral ligament ruptures. It can also be used as a dynamic method for stress examination in fibular ligament ruptures and soft tissue injuries such as dislocation of the peroneal tendons. The use of Arthrography, stress tenography, and Arthro-CT scan nowadays has become extremely limited.

  20. [Joint surface resection with a minimally invasive dorsal approach for arthrodesis of the distal interphalangeal joint].

    PubMed

    Ayala-Gamboa, U; Domínguez-Chacón, N D

    2015-01-01

    Degenerative joint disease of the distal interphalangeal joint of the fingers precedes its occurrence in all the remaining regions of the body and produces major disability. We describe a distal interphalangeal arthrodesis technique performed with minimally invasive surgery. Case etiology was varied and mean follow-up was 10 months. All cases healed and functional recovery started at postoperative week two. This is a reproducible technique that produces satisfactory results in the short and medium term.

  1. [The Arthur Vick Award: kinematics of the metacarpophalangeal joint after surface replacement arthroplasty].

    PubMed

    Fayaz, H C; Beckenbaugh, R D; An, K N; Klawitter, J J; Jerosch, J; Rehart, S; Cooney, W P

    2007-01-01

    Prosthetic replacement in the hand must address such unique challenges as preservation of the collateral ligaments, tendon balancing,and Stability. Surface replacement arthroplasty can be an alternative to other current implants. The purpose of this study was to evaluate the metacarpophalangeal joint kinematics after surface replacement arthroplasty. The kinematics of pyrolytic carbon as a surface replacement implant for the metacarpophalangeal joint (MCP) was compared with the intact MCP joint in eight fresh cadaver long fingers by means of an electromagnetic tracking system (Polhemus, Colchester, VT). The eight human cadaver MCP joints were tested before implantation, after implantation, after collateral ligaments resection, and after collateral ligaments reconstruction. The kinematics of the MCP joint is reproduced by the joint surface replacement arthroplasty when normal ligament tension was present. The maximum angular displacement of the pyrocarbon implant was 378 for lateral deviation and 338 for rotation during the passive flexion and extension motion. The instantaneus center of rotation (ICR) after implant insertion was nearly identical to the center of rotation of the normal joint. The results also indicated that the collateral ligaments provide the primary stability of the MCP joint. No significant differences in lateral and rotational stability after surface replacement arthroplasty were noted. While collateral ligaments resection significantly affected the stability of the MCP joint. The ICR of the pyrocarbon implant most closely matched that of the intact MCP joint. The pyrocarbon implant provides suitable stability to radio-ulnar deviation and rotational stresses as a resurfacing implant and it simulates the kinematics of the intact MCP joint. By using new materials and taking the anatomical and biomechanical requirements into consideration, the endoprosthesis of the finger joints has created an option to achieve good long-term results. The

  2. A novel modelling and simulation method of hip joint surface contact stress.

    PubMed

    Wang, Monan; Wang, Lei; Li, Pengcheng; Fu, Yili

    2017-01-02

    Understanding the hip joint surface contact stress distribution characteristics is helpful to determine hip joint biomechanical features and abnormal pathological behavior. Firstly, a 3-dimensional static hip joint biomechanical model is built using analytical method of model in order to study biomechanical properties including bearing area, stress distribution and the peak value of the contact stress of the femoral head, which reveals the relationship between the biomechanical properties and its geometric parameters. Secondly, based on the finite element analysis of the hip joint model, the contact stress distribution on the surface of femoral head is acquired under the condition of the different joint force and the acetabulum coverage rate. Finally, according to the evaluation of the femoral head surface stress and contact stress peak under different load distribution, accuracy and universality of the biomechanical model is verified.

  3. A surface roughness comparison of cartilage in different types of synovial joints.

    PubMed

    Smyth, Patrick A; Rifkin, Rebecca E; Jackson, Robert L; Hanson, R Reid

    2012-02-01

    The naturally occurring structure of articular cartilage has proven to be an effective means for the facilitation of motion and load support in equine and other animal joints. For this reason, cartilage has been extensively studied for many years. Although the roughness of cartilage has been determined from atomic force microscopy (AFM) and other methods in multiple studies, a comparison of roughness to joint function has not be completed. It is hypothesized that various joint types with different motions and regimes of lubrication have altered demands on the articular surface that may affect cartilage surface properties. Micro- and nanoscale stylus profilometry was performed on the carpal cartilage harvested from 16 equine forelimbs. Eighty cartilage surface samples taken from three different functioning joint types (radiocarpal, midcarpal, and carpometacarpal) were measured by a Veeco Dektak 150 Stylus Surface Profilometer. The average surface roughness measurements were statistically different for each joint. This indicates that the structure of cartilage is adapted to, or worn by, its operating environment. Knowledge of cartilage micro- and nanoscale roughness will assist the future development and design of treatments for intra- articular substances or surfaces to preserve joint integrity and reduce limitations or loss of joint performance.

  4. The joint effect of surface microtopography and near-surface structure on microcontact conditions

    SciTech Connect

    McCool, J.I.

    1990-11-01

    This is the Final Technical Report of the project The Joint Effect of Surface Microtopography and Near Surface Structure on Microcontact Conditions The purpose of this project was to extend, apply, and evaluate the usefuleness of, microcontact models for assessing the tribological performance of machine elements in rolling/sliding contact. Because of their projected importance to the field of energy conservation, emphasis was placed on application to ceramic and coated specimens. The project was multi-institutional as well as multi-disciplinary with technical contributions in testing and the evaluation of specimens by the Argonne National Laboratory (G. Fenske), Oak Ridge National Laboratory (P. Blau), and the University of Michigan (K. Ludema and Layo Ajayi). To accomplish the Project aims it was necessary to extend the state-of-the-art of microcontact modelling. 59 refs., 46 figs., 35 tabs.

  5. THE PROSTAGLANDIN E2 RECEPTOR, EP2, IS UPREGULATED IN THE DRG AFTER PAINFUL CERVICAL FACET JOINT INJURY IN THE RAT

    PubMed Central

    Kras, Jeffrey V.; Dong, Ling; Winkelstein, Beth A.

    2012-01-01

    Study Design This study implemented immunohistochemistry to assay prostaglandin E2 (PGE2) receptor EP2 expression in the dorsal root ganglion (DRG) of rats after painful cervical facet joint injury. Objective The objective of this study was to identify if inflammatory cascades are induced in association with cervical facet joint distraction-induced pain by investigating the time course of EP2 expression in the DRG. Summary of Background Data The cervical facet joint is a common source of neck pain and non-physiological stretch of the facet capsular ligament can initiate pain from the facet joint via mechanical injury. PGE2 levels are elevated in painful inflamed and arthritic joints, and PGE2 sensitizes joint afferents to mechanical stimulation. Although in vitro studies suggest the EP2 receptor subtype contributes to painful joint disease the EP2 response has not been investigated for any association with painful mechanical joint injury. Methods Separate groups of male Holtzman rats underwent either a painful cervical facet joint distraction injury or sham procedure. Bilateral forepaw mechanical allodynia was assessed, and immunohistochemical techniques were used to quantify EP2 expression in the DRG at days 1 and 7. Results Facet joint distraction induced mechanical allodynia that was significant (p<0.024) at all time points. Painful joint injury also significantly elevated total EP2 expression in the DRG at day 1 (p=0.009), which was maintained also at day 7 (p<0.001). Neuronal expression of EP2 in the DRG was only increased over sham levels at day 1 (p=0.013). Conclusions Painful cervical facet joint distraction induces an immediate and sustained increase of EP2 expression in the DRG, implicating peripheral inflammation in the initiation and maintenance of facet joint pain. The transient increase in neuronal EP2 suggests, as in other painful joint conditions, that after joint injury non-neuronal cells may migrate to the DRG, some of which likely express EP2

  6. Topical diagnostics of traumatic condylar injuries and alloplastic reconstruction of temporomandibular joint heads.

    PubMed

    Gvenetadze, Z; Danelia, T; Nemsadze, G; Gvenetadze, G

    2014-04-01

    Condylar fractures have an important place in facial traumatic injuries. Classification of condylar fractures according to clinical-anatomic picture is common in clinical practice. According to this classification there are: 1) fractures of mandibular joint head, aka intraarticular fractures, 2) condylar neck fractures or high extra articular fractures, 3) condylar base fractures. Radiographic imaging plays important role in diagnosing condylar fractures along with knowledge of clinical symptoms. We used computer tomography imaging in our clinical practice. Three-dimensional imaging of computer tomography gives exact information about location of condylar fractures, impact of fractured fragments, displacement of condylar head from articular fossa. This method is mostly important for the cases which are hard to diagnose (fractures of mandibular joint head, aka intraarticular fractures). For this group of patients surgical treatment is necessary with the method of arthroplasty. We have observed 5 patients with bilateral, fragmented, high condylar fractures. In all cases the surgery was performed on both sides with bone cement and titanium mini-plates. Long-term effects of the treatment included observation from 6 months to 2 years. In all cases anatomic and functional results were good. Shape of the mandible is restored, opening of mouth 3-3.5 cm, absence of malocclusion.

  7. Quantitation of articular surface topography and cartilage thickness in knee joints using stereophotogrammetry.

    PubMed

    Ateshian, G A; Soslowsky, L J; Mow, V C

    1991-01-01

    An analytical stereophotogrammetry (SPG) technique has been developed based upon some of the pioneering work of Selvik [Ph.D. thesis, University of Lund, Sweden (1974)] and Huiskes and coworkers [J. Biomechanics 18, 559-570 (1985)], and represents a fundamental step in the construction of biomechanical models of diarthrodial joints. Using this technique, the precise three-dimensional topography of the cartilage surfaces of various diarthrodial joints has been obtained. The system presented in this paper delivers an accuracy of 90 microns in the least favorable conditions with 95% coverage using the same calibration method as Huiskes et al. (1985). In addition, a method has been developed, using SPG, to quantitatively map the cartilage thickness over the entire articular surface of a joint with a precision of 134 microns (95% coverage). In the present study, our SPG system has been used to quantify the topography, including surface area, of the articular surfaces of the patella, distal femur, tibial plateau, and menisci of the human knee. Furthermore, examples of cartilage thickness maps and corresponding thickness data including coefficient of variation, minimum, maximum, and mean cartilage thickness are also provided for the cartilage surfaces of the knee. These maps illustrate significant variations over the joint surfaces which are important in the determination of the stresses and strains within the cartilage during diarthrodial joint function. In addition, these cartilage surface topographies and thickness data are essential for the development of anatomically accurate finite element models of diarthrodial joints.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Comparison of Extension Orthosis Versus Percutaneous Pinning of the Distal Interphalangeal Joint for Closed Mallet Injuries.

    PubMed

    Renfree, Kevin J; Odgers, Ryan A; Ivy, Cynthia C

    2016-05-01

    We compared a static extension orthosis with percutaneous pinning of the distal interphalangeal joint (DIPJ) for treatment of closed mallet injuries. After receiving counsel about treatment options, 44 patients (25 women and 19 men; mean age, 57 years) freely chose orthosis and 18 patients (5 women and 13 men; mean age, 51 years) chose pinning. Both the extension orthosis and the pin remained in place for 6 weeks; the pin then was removed, and the care in both groups was transitioned to nighttime orthosis use for an additional 6 weeks. The patients in the pin group were allowed to immediately resume unrestricted activity postoperatively. The mean follow-up was 32 months in the orthosis group and 19 months in the pin group. Final residual extensor lag was better in the pin group (5 vs 10 degrees, P = 0.048). Improvement between the groups was in favor of percutaneous pinning (36 vs 17 degrees, P = 0.001). No correlation was seen between time to treatment (≤14 vs >14 days from injury) and final extensor lag in either group (P = 0.85). The final mean DIPJ flexion was 53 degrees for orthosis and 46 degrees for pinning. Among the patients, 93% of the orthosis group and 100% of the pin group said that they would choose the same treatment again. Both groups had a mean of 5 hand therapy visits during treatment. Two complications occurred in the orthosis group (5%) and 3 (17%) occurred in the pin group. Extension orthotics and pinning are both well-tolerated, effective treatments of mallet injury. The techniques produce satisfactory correction of extensor lag and have high patient satisfaction. Pinning allows better correction of DIPJ extensor lag and results in a smaller degree of final extensor lag. Pinning is more expensive and may result in more DIPJ stiffness (ie, loss of active flexion), but it may be justified in certain patients (eg, medical professionals, food service workers) who would have difficulty working with an orthosis.

  9. Motor impairments related to brain injury timing in early hemiparesis. Part II: abnormal upper extremity joint torque synergies.

    PubMed

    Sukal-Moulton, Theresa; Krosschell, Kristin J; Gaebler-Spira, Deborah J; Dewald, Julius P A

    2014-01-01

    Extensive neuromotor development occurs early in human life, and the timing of brain injury may affect the resulting motor impairment. In Part I of this series, it was demonstrated that the distribution of weakness in the upper extremity depended on the timing of brain injury in individuals with childhood-onset hemiparesis. The goal of this study was to characterize how timing of brain injury affects joint torque synergies, or losses of independent joint control. Twenty-four individuals with hemiparesis were divided into 3 groups based on the timing of their injury: before birth (PRE-natal, n = 8), around the time of birth (PERI-natal, n = 8), and after 6 months of age (POST-natal, n = 8). Individuals with hemiparesis and 8 typically developing peers participated in maximal isometric shoulder, elbow, wrist, and finger torque generation tasks while their efforts were recorded by a multiple degree-of-freedom load cell. Motor output in 4 joints of the upper extremity was concurrently measured during 8 primary torque generation tasks to quantify joint torque synergies. There were a number of significant coupling patterns identified in individuals with hemiparesis that differed from the typically developing group. POST-natal differences were most noted in the coupling of shoulder abductors with elbow, wrist, and finger flexors, while the PRE-natal group demonstrated significant distal joint coupling with elbow flexion. The torque synergies measured provide indirect evidence for the use of bulbospinal pathways in the POST-natal group, while those with earlier injury may use relatively preserved ipsilateral corticospinal motor pathways.

  10. Modelling the effect of race surface and racehorse limb parameters on in silico fetlock motion and propensity for injury.

    PubMed

    Symons, J E; Hawkins, D A; Fyhrie, D P; Upadhyaya, S K; Stover, S M

    2017-09-01

    The metacarpophalangeal joint (fetlock) is the most commonly affected site of racehorse injury, with multiple observed pathologies consistent with extreme fetlock dorsiflexion. Race surface mechanics affect musculoskeletal structure loading and injury risk because surface forces applied to the hoof affect limb motions. Race surface mechanics are a function of controllable factors. Thus, race surface design has the potential to reduce the incidence of musculoskeletal injury through modulation of limb motions. However, the relationship between race surface mechanics and racehorse limb motions is unknown. To determine the effect of changing race surface and racehorse limb model parameters on distal limb motions. Sensitivity analysis of in silico fetlock motion to changes in race surface and racehorse limb parameters using a validated, integrated racehorse and race surface computational model. Fetlock motions were determined during gallop stance from simulations on virtual surfaces with differing average vertical stiffness, upper layer (e.g. cushion) depth and linear stiffness, horizontal friction, tendon and ligament mechanics, as well as fetlock position at heel strike. Upper layer depth produced the greatest change in fetlock motion, with lesser depths yielding greater fetlock dorsiflexion. Lesser fetlock changes were observed for changes in lower layer (e.g. base or pad) mechanics (nonlinear), as well as palmar ligament and tendon stiffness. Horizontal friction and fetlock position contributed less than 1° change in fetlock motion. Simulated fetlock motions are specific to one horse's anatomy reflected in the computational model. Anatomical differences among horses may affect the magnitude of limb flexion, but will likely have similar limb motion responses to varied surface mechanics. Race surface parameters affected by maintenance produced greater changes in fetlock motion than other parameters studied. Simulations can provide evidence to inform race surface

  11. [Research on surface modification and bio-tribological properties of artificial joint].

    PubMed

    Pan, Yusong; Wang, Jing; Ding, Guoxin

    2012-06-01

    The bio-tribological properties of an artificial joint can be obviously improved by surface modification technologies. In this paper, the benefits and disadvantages of various surface modification methods-such as surface coating, plasma treatment, surface texture and surface grafting modification-are discussed. The aim of surface coating and/or plasma treatment is to improve the surface hardness of the materials, thus enhancing the wear resistance of artificial joints. However, these technologies do not effectively alleviate stress concentration of material in the short times in which artificial joints bear physiological impact load, resulting in easy fracture. Surface texture serves mainly to improve the lubrication properties through micro-concavities on the material surface for storage lubricant. Surface texturing can realize improvements in bio-tribological properties, but it does not enhance the impact resistance of the joint. Surface grafting modification is implemented mainly by grafting hydrophilic or other specific functional groups to improve the surface hydrophilicity and wetability, thus enhancing lubricating performance and reducing the coefficient of friction.

  12. Surface Modification by Nanoimprint Lithography for Improvement of the Joint Strength of Composites

    NASA Astrophysics Data System (ADS)

    Matsuzaki, Ryosuke; Suzuki, Takuya

    To improve the strength of adhesively bonded composite joints, surface modification of composites by nanoimprint lithography (NIL) is investigated. Since microstructures can be fabricated during the curing of composites, this technique reduces the time required and costs involved in conventional surface preparation such as chemical etching or sand blasting. Since structural adhesives are susceptible to peeling, a pyramidal microstructure is chosen for the surface modification pattern. Such a pattern divides the stress at the interface into peel and shear components; thus, the apparent joint strength is greater than that of an untreated joint with a flat surface. We fabricated the pyramidal microstructure on carbon fiber reinforced plastic and determined the adhesive strength both analytically and experimentally. In the analysis, interfacial stresses were calculated using the finite element method and the interfacial fracture was defined using the peel and shear mixed-mode criterion based on the average stress criterion. In the experiment, tensile butt joint tests were performed for NIL and untreated joints and the apparent strengths were measured. The NIL joint was found to be 52% stronger than the untreated joint according to the finite element method calculation and 67% stronger according to the tensile tests.

  13. [Analysis of knee joint injuries of competitive volleyball players in selected sports clubs of Poznan city--biomechanical context. Synthesis--proposal for the usage of physiotherapy methods in the prevention of the discussed injuries].

    PubMed

    Dworak, Lechosław B; Rzepnicka, Agata; Wilkosz, Piotr; Szczesny, Łukasz

    2010-01-01

    Volleyball is a source of direct injuries and chronic overloads of the joints, which indirectly results in traumas and permanent dysfunctions. This applies particularly to: knee joints, ankle joints, shoulder joints and small joints of the hand, as well as the joints of the lower spine regions. Each league team should employ a physiotherapist who would be responsible for the implementation of an injury prevention program as well as for choosing the right training loads. The purpose of this study is to analyze the frequency and the type of knee joint injuries occurring in people practicing Volleyball at competitive level as well as to propose the usage of elements of modern physiotherapy in order to prevent these injuries. The tests were performed over a group of 19 volleyball players from Poznan. In order to propose measures that would prevent injuries, the authors carried out a review of modern physiotherapy methods and suggested the implementation of certain therapeutic techniques for the region of the knee joint. RESULT ANALYSIS AND DISCUSSION: As much as 79% of the subjects reported having chronic pain and knee joint injuries in the past. All of them, due to their conditions, declared having used various forms of physiotherapy treatment. It seems that in a professional sports club not only the presence of a massage therapist but first of all a qualified physiotherapist is indispensable.

  14. Improving Joint Function Using Photochemical Hydrogels for Articular Surface Repair

    DTIC Science & Technology

    2017-02-01

    outcomes of our studies, since mature TGF-b1 is known to be highly conserved (>99% amino acid sequence identity ) throughout mammalian species.39 The data...vasculature, cartilage exhibits a low rate of regeneration; hence, focal lesions caused by trauma or joint disorders can lead to debilitating...the dye reagent (Biocolor, Carrickfergus, United Kingdom) containing 1,9-dimethyl-methylene blue, the dissociation reagent (Biocolor) containing the

  15. No Effect of Generalized Joint Hypermobility on Injury Risk in Elite Female Soccer Players: A Prospective Cohort Study.

    PubMed

    Blokland, Donna; Thijs, Karin M; Backx, Frank J G; Goedhart, Edwin A; Huisstede, Bionka M A

    2017-02-01

    Although it has been suggested that generalized joint hypermobility (GJH) is a risk factor for injury in soccer players, it remains unclear whether this applies to elite female soccer players. To investigate whether GJH is a risk factor for injury in elite female soccer players. Cohort study; Level of evidence, 2. Elite female soccer players in the Netherlands were screened at the start of the 2014-2015 competitive season. GJH was assessed using the Beighton score. Soccer injuries and soccer exposure were registered throughout the entire season. Poisson regression was performed to calculate incidence risk ratios (IRRs) using different cutoff points of the Beighton score (≥3, ≥4, and ≥5) to indicate GJH. Of the 114 players included in the study, 20 were classified as hypermobile (Beighton score ≥4). The mean (±SD) injury incidence per player was 8.40 ± 9.17 injuries/1000 hours of soccer, with no significant difference between hypermobile and nonhypermobile players. GJH was not a risk factor for injuries when using Beighton score cutoff points of ≥3 (IRR = 1.06 [95% CI, 0.74-1.50]; P = .762), ≥4 (IRR = 1.10 [95% CI, 0.72-1.68]; P = .662), or ≥5 (IRR = 1.15 [95% CI, 0.68-1.95]; P = .602). Similarly, GJH was not a significant risk factor for thigh, knee, or ankle injuries evaluated separately. This study indicates that GJH is not a risk factor for injuries in elite female soccer players, irrespective of Beighton score cutoff point. Hypermobile players at this elite level might have improved their active stability and/or used braces to compensate for joint laxity.

  16. Joint-specific changes in locomotor complexity in the absence of muscle atrophy following incomplete spinal cord injury

    PubMed Central

    2013-01-01

    Background Following incomplete spinal cord injury (iSCI), descending drive is impaired, possibly leading to a decrease in the complexity of gait. To test the hypothesis that iSCI impairs gait coordination and decreases locomotor complexity, we collected 3D joint angle kinematics and muscle parameters of rats with a sham or an incomplete spinal cord injury. Methods 12 adult, female, Long-Evans rats, 6 sham and 6 mild-moderate T8 iSCI, were tested 4 weeks following injury. The Basso Beattie Bresnahan locomotor score was used to verify injury severity. Animals had reflective markers placed on the bony prominences of their limb joints and were filmed in 3D while walking on a treadmill. Joint angles and segment motion were analyzed quantitatively, and complexity of joint angle trajectory and overall gait were calculated using permutation entropy and principal component analysis, respectively. Following treadmill testing, the animals were euthanized and hindlimb muscles removed. Excised muscles were tested for mass, density, fiber length, pennation angle, and relaxed sarcomere length. Results Muscle parameters were similar between groups with no evidence of muscle atrophy. The animals showed overextension of the ankle, which was compensated for by a decreased range of motion at the knee. Left-right coordination was altered, leading to left and right knee movements that are entirely out of phase, with one joint moving while the other is stationary. Movement patterns remained symmetric. Permutation entropy measures indicated changes in complexity on a joint specific basis, with the largest changes at the ankle. No significant difference was seen using principal component analysis. Rats were able to achieve stable weight bearing locomotion at reasonable speeds on the treadmill despite these deficiencies. Conclusions Decrease in supraspinal control following iSCI causes a loss of complexity of ankle kinematics. This loss can be entirely due to loss of supraspinal control in

  17. Are joint injury, sport activity, physical activity, obesity, or occupational activities predictors for osteoarthritis? A systematic review.

    PubMed

    Richmond, Sarah A; Fukuchi, Reginaldo K; Ezzat, Allison; Schneider, Kathryn; Schneider, Geoff; Emery, Carolyn A

    2013-08-01

    Systematic review with meta-analysis. To identify risk factors for osteoarthritis (OA) of the knee, hip, and ankle, including joint injury, sport, physical activity, overweight/obesity, and occupational activity, in all age groups. OA is a significant health problem worldwide, affecting up to 10% of men and 18% of women over 60 years of age. There has not been a comprehensive review examining modifiable physical risk factors associated with the onset of OA. This evidence is important to inform the physiotherapy management of individuals following onset of OA. Twelve electronic databases were systematically reviewed. The studies selected met the following criteria: (1) original data; (2) joint injury, sport activity, physical activity, overweight/obesity, and/or occupational activity investigated as risk factors; (3) outcomes included OA (hip, knee, and/or ankle); and (4) analytic component of study design. The data extracted included study design, years of follow-up, study population, OA definition, risk factors, and results (effect estimates reported or calculated where available). The quality of evidence was assessed based on a modified version of the Downs and Black checklist. Joint injury, obesity, and occupational activity were associated with an increased risk of OA of the knee and hip. Sport and physical activity produced inconsistent findings. Joint injury was identified as a significant risk factor for knee OA (combined odds ratio = 3.8; 95% confidence interval: 2.0, 7.2) and hip OA (combined odds ratio = 5.0; 95% confidence interval: 1.4, 18.2), as was previous meniscectomy with or without anterior cruciate ligament injury for knee OA (combined odds ratio = 7.4; 95% confidence interval: 4.0, 13.7). There is a paucity of research examining risk factors associated with ankle OA; this review identified only 2 studies with this outcome. Joint injury, obesity, and occupational activity are associated with an increased risk of knee and hip OA. Some findings

  18. The Effects of Generalized Joint Laxity on Risk of Anterior Cruciate Ligament Injury in Young Female Athletes

    PubMed Central

    Myer, Gregory D.; Ford, Kevin R.; Paterno, Mark V.; Nick, Todd G.; Hewett, Timothy E.

    2012-01-01

    Background Women who participate in high-risk sports suffer anterior cruciate ligament injury at a 4- to 6-fold greater rate than men. Purpose To prospectively determine if female athletes with decreased passive knee joint restraint (greater joint laxity) and greater side-to-side differences in knee laxity would be at increased risk of anterior cruciate ligament injury. Study Design Case control study; Level of evidence, 3. Methods From 1558 female soccer and basketball players who were prospectively screened, 19 went on to tear their anterior cruciate ligaments. Four height- and mass-matched control subjects were selected from the uninjured screened athletes for comparison with each of the 19 injured subjects, making a total of 95 subjects (19 injured; 76 uninjured). Generalized joint-laxity tests and anterior-posterior tibiofemoral translation were quantified using the CompuKT knee arthrometer. A multivariable logistic regression model was constructed to determine predictors of anterior cruciate ligament injury status from recorded laxity measures. Results A multivariable logistic regression model (chi-square = 18.6; P = .002) used the independent variables laxity measures of knee hyperextension (P = .02), wrist and thumb to forearm opposition (P = .80), fifth-finger hyperextension >90° (P = .71), side-to-side differences in anterior-posterior tibiofemoral translation (P = .002), and prior knee injury (P = .22) to predict anterior cruciate ligament–injury status. The validated C statistic, or validated area under the receiver operating characteristic curve, was 0.72. For every 1.3-mm increase in side-to-side differences in anterior-posterior knee displacement, the odds of anterior cruciate ligament–injured status increased 4-fold (95% confidence interval, 1.68–9.69). A positive measure of knee hyperextension increased the odds of anterior cruciate ligament–injured status 5-fold (95% confidence interval, 1.24–18.44). Conclusion The current results

  19. Surface Modifications for Improved Wear Performance in Artificial Joints: A Review

    NASA Astrophysics Data System (ADS)

    Sullivan, Stacey J. L.; Topoleski, L. D. Timmie

    2015-11-01

    Artificial joint replacement is one of the most successful treatments for arthritis. Excellent wear and corrosion resistance, together with high strength and fracture toughness, are fundamental requirements for implant materials. Wear and/or corrosion of the materials used in artificial joints may lead to implant failure. Therefore, hard and wear-resistant materials, like cobalt-chromium-molybdenum and ceramic, are currently used as bearing surfaces. However, even using such hard materials, wear and/or corrosion related failure of artificial joints remains a central concern. One primary goal in orthopedic biomaterials research is to create more wear-resistant surfaces. Different technologies have been used to create new surfaces, or to modify existing surfaces, to prevent wear. It is the intent of this overview first to provide a summary of materials currently used as bearing surfaces in artificial joints, their functions, and their contributions to device longevity. Then, we will discuss advancements in modifying those bearing surfaces to produce more wear-resistant artificial joints.

  20. Value of ultrasonography for detecting chronic injury of the lateral ligaments of the ankle joint compared with ultrasonography findings

    PubMed Central

    Cheng, Y; Cai, Y

    2014-01-01

    Objective: The aim of this study was to assess the accuracy of ultrasonography in the diagnosis of chronic lateral ankle ligament injury. Methods: A total of 120 ankles in 120 patients with a clinical suspicion of chronic ankle ligament injury were examined by ultrasonography by using a 5- to 17-MHz linear array transducer before surgery. The results of ultrasonography were compared with the operative findings. Results: There were 18 sprains and 24 partial and 52 complete tears of the anterior talofibular ligament (ATFL); 26 sprains, 27 partial and 12 complete tears of the calcaneofibular ligament (CFL); and 1 complete tear of the posterior talofibular ligament (PTFL) at arthroscopy and operation. Compared with operative findings, the sensitivity, specificity and accuracy of ultrasonography were 98.9%, 96.2% and 84.2%, respectively, for injury of the ATFL and 93.8%, 90.9% and 83.3%, respectively, for injury of the CFL. The PTFL tear was identified by ultrasonography. The accuracy of identification between acute-on-chronic and subacute–chronic patients did not differ. The accuracies of diagnosing three grades of ATFL injuries were almost the same as those of diagnosing CFL injuries. Conclusion: Ultrasonography provides useful information for the evaluation of patients presenting with chronic pain after ankle sprain. Advances in knowledge: Intraoperative findings are the reference standard. We demonstrated that ultrasonography was highly sensitive and specific in detecting chronic lateral ligments injury of the ankle joint. PMID:24352708

  1. Surface replacement arthroplasty of the proximal interphalangeal and metacarpophalangeal joints: The current state

    PubMed Central

    Singh, Harvinder; Dias, Joseph J.

    2011-01-01

    Surface replacement arthroplasty for proximal interphalangeal joint and metacarpophalangeal joints are becoming popular. Low profile, anatomically designed implants limit the amount of bone removed but need preservation of the collateral ligaments. Pyrocarbon and cobalt-chrome stemmed unconstrained implants on ultra-high molecular weight polyethylene are the two commonly available bearing surfaces. The indications for small joint arthroplasty are degenerative, post-traumatic or rheumatoid arthritis. Early results are encouraging, primarily in patient satisfaction and pain relief, but are based on low numbers. The main concerns are progressive loss of range due to implant settling, dislocation, squeaking and poor osteo-integration with the appearance of a radiolucent line at the bone–implant interface. Our experience suggests that metacarpophalangeal joint replacements consistently give good results. PMID:22022042

  2. Activity vs. rest in the treatment of bone, soft tissue and joint injuries.

    PubMed Central

    Buckwalter, J. A.

    1995-01-01

    One of the most important advances in the treatment of musculoskeletal injuries has come from understanding that controlled early resumption of activity can promote restoration of function, and that treatment of injuries with prolonged rest may delay recovery and adversely affect normal tissues. In the last decade of the nineteenth century two widely respected orthopaedists with extensive clinical experience strongly advocated opposing treatments of musculoskeletal injuries. Hugh Owen Thomas in Liverpool believed that enforced, uninterrupted prolonged rest produced the best results. He noted that movement of injured tissues increased inflammation, and that, "It would indeed be as reasonable to attempt to cure a fever patient by kicking him out of bed, as to benefit joint disease by a wriggling at the articulation." Just Lucas-Championnier in Paris took the opposite position. He argued that early controlled active motion accelerated restoration of function, although he noted that mobility had to be given in limited doses. In general, Thomas' views met with greater acceptance in the early part of this century, but experimental studies of the last several decades generally support Lucas-Championneir. They confirm and help explain the deleterious effects of prolonged rest and the beneficial effects of activity on the musculoskeletal tissues. They have shown that maintenance of normal bone, tendon and ligament, articular cartilage and muscle structure and composition require repetitive use, and that changes in the patterns of tissue loading can strengthen or weaken normal tissues. Although all the musculoskeletal tissues can respond to repetitive loading, they vary in the magnitude and type of response to specific patterns of activity. Furthermore, their responsiveness may decline with increasing age. Skeletal muscle and bone demonstrate the most apparent response to changes in activity in individuals of any age. Cartilage and dense fibrous tissues also can respond to

  3. New Peak Shear Strength Criterion of Rock Joints Based on Quantified Surface Description

    NASA Astrophysics Data System (ADS)

    Xia, Cai-Chu; Tang, Zhi-Cheng; Xiao, Wei-Min; Song, Ying-Long

    2014-03-01

    The prime objective of this work is to improve our understanding of the shear behavior of rock joints. Attempts are made to relate the peak shear strength of rock joints with its three-dimensional surface morphology parameters. Three groups of tensile joint replicas with different surface morphology are tested with direct shear tests under constant normal load (CNL) conditions. Firstly, the three-dimensional surface characterization of these joints is evaluated by an improved roughness parameter before being tested. Then, a new empirical criterion is proposed for these joints expressed by three-dimensional quantified surface roughness parameters without any averaging variables in such a way that a rational dilatancy angle function is used instead of by satisfying the new peak dilatancy angle boundary conditions under zero and critical-state normal stress (not physical infinite normal stress). The proposed criterion has the capability of estimating the peak shear strength at the laboratory scale and the required roughness parameters can be easily measured. Finally, a comparison among the proposed criterion, Grasselli's criterion, and Barton's criterion are made from the perspective of both the rationality of the formula and the prediction accuracy for the three groups of joints. The limitations of Grasselli's criterion are analyzed in detail. Another 37 experimental data points of fresh rock joints by Grasselli are used to further verify the proposed criterion. Although both the proposed criterion and Grasselli's criterion have almost equal accuracy of predicting the peak shear strength of rock joints, the proposed criterion is easier and more intuitive from an engineering point of view because of its Mohr-Coulomb type of formulation.

  4. Arthroscopic-assisted repair of triangular fibrocartilage complex foveal avulsion in distal radioulnar joint injury

    PubMed Central

    Woo, Sung Jong; Jegal, Midum; Park, Min Jong

    2016-01-01

    Background: Disruption of the triangular fibrocartilage complex (TFCC) foveal insertion can lead to distal radioulnar joint (DRUJ) instability accompanied by ulnar-sided pain, weakness, snapping, and limited forearm rotation. We investigated the clinical outcomes of patients with TFCC foveal tears treated with arthroscopic-assisted repair. Materials and Methods: Twelve patients underwent foveal repair of avulsed TFCC with the assistance of arthroscopy between 2011 and 2013. These patients were followed up for an average of 19 months (range 14–25 months). The avulsed TFCC were reattached to the fovea using a transosseous pull-out suture or a knotless suture anchor. At the final followup, the range of motion, grip strength and DRUJ stability were measured as objective outcomes. Subjective outcomes were assessed using the Visual Analog Scale (VAS) for pain, patient rated wrist evaluation (PRWE), Disabilities of the Arm, Shoulder and Hand questionnaire (DASH score) and return to work. Results: Based on the DRUJ stress test, 5 patients had normal stability and 7 patients showed mild laxity as compared with the contralateral side. Postoperatively, the mean range of pronation supination increased from 141° to 166°, and the mean VAS score for pain decreased from 5.3 to 1.7 significantly. The PRWE and DASH questionnaires also showed significant functional improvement. All patients were able to return to their jobs. However, two patients complained of persistent pain. Conclusions: Arthroscopically assisted repair of TFCC foveal injury can provide significant pain relief, functional improvement and restoration of DRUJ stability. PMID:27293286

  5. Manual Medicine Related Injuries Experienced by Physicians: A Missing Aspect in Therapies Using Manipulation of Joints

    PubMed Central

    Steinhaeuser, Jost; Oser, Andreas

    2015-01-01

    Background. In 2010 Manual Medicine (MM) was the second most common additional qualification among physicians in Germany, which is recommended to be used in several guidelines. Aim of this analysis was to raise the amount of information on MM related injuries (MMri) experienced by physicians at any point of their career while applying MM. Methods. Data on MMri of a questionnaire that was used to gain first insights into MM in Germany from a health services research perspective was analysed. Results. A total of 301 physicians (20% female) participated in this study. The participants' mean age was 46. 11% of the participants experienced some kind of MMri during their career as a MM provider. In the three worst cases these MMri were fractures and therefore classified as moderate. Mild MMri were joint dysfunction syndromes (N = 30), distortions of fingers (N = 7), and shoulder pain (N = 3). Subgroup analyses showed no significant differences in the rate of MMri when comparing gender, provider organizations for postgraduate MM courses, and medical disciplines. Conclusion. Our analysis shows risks for providers of MM. As this analysis suffers from the risk of recall bias, future studies should be performed to get more insights into this aspect of MM. PMID:25815036

  6. Association of lower limb injury with boot cleat design and playing surface in elite soccer.

    PubMed

    O'Connor, Anne-Marie; James, Iain T

    2013-06-01

    Reducing external injury risk factors associated with the boot-surface interaction is important in reducing the incidence and severity of foot and ankle injury. A review of prospective football (soccer) injury epidemiology studies determined that the incidence of noncontact ankle sprain injury is relatively high. Research on the impact of cleat shape and configuration and boot design on the boot-surface interaction is providing new understanding of the impact on player biomechanics and injury risk but is not keeping pace with commercial advances in boot design and innovation in natural and synthetic turf surface technology.

  7. Ketorolac Reduces Spinal Astrocytic Activation and PAR1 Expression Associated with Attenuation of Pain after Facet Joint Injury

    PubMed Central

    Dong, Ling; Smith, Jenell R.

    2013-01-01

    Abstract Chronic neck pain affects up to 70% of persons, with the facet joint being the most common source. Intra-articular injection of the non-steroidal anti-inflammatory drug ketorolac reduces post-operative joint-mediated pain; however, the mechanism of its attenuation of facet-mediated pain has not been evaluated. Protease-activated receptor-1 (PAR1) has differential roles in pain maintenance depending on the type and location of painful injury. This study investigated if the timing of intra-articular ketorolac injection after painful cervical facet injury affects behavioral hypersensitivity by modulating spinal astrocyte activation and/or PAR1 expression. Rats underwent a painful joint distraction and received an injection of ketorolac either immediately or 1 day later. Separate control groups included injured rats with a vehicle injection at day 1 and sham operated rats. Forepaw mechanical allodynia was measured for 7 days, and spinal cord tissue was immunolabeled for glial fibrillary acidic protein (GFAP) and PAR1 expression in the dorsal horn on day 7. Ketorolac administered on day 1 after injury significantly reduced allodynia (p=0.0006) to sham levels, whereas injection immediately after the injury had no effect compared with vehicle. Spinal astrocytic activation followed behavioral responses and was significantly decreased (p=0.009) only for ketorolac given at day 1. Spinal PAR1 (p=0.0025) and astrocytic PAR1 (p=0.012) were significantly increased after injury. Paralleling behavioral data, astrocytic PAR1 was returned to levels in sham only when ketorolac was administered on day 1. Yet, spinal PAR1 was significantly reduced (p<0.0001) by ketorolac independent of timing. Spinal astrocyte expression of PAR1 appears to be associated with the maintenance of facet-mediated pain. PMID:23126437

  8. Ketorolac reduces spinal astrocytic activation and PAR1 expression associated with attenuation of pain after facet joint injury.

    PubMed

    Dong, Ling; Smith, Jenell R; Winkelstein, Beth A

    2013-05-15

    Chronic neck pain affects up to 70% of persons, with the facet joint being the most common source. Intra-articular injection of the non-steroidal anti-inflammatory drug ketorolac reduces post-operative joint-mediated pain; however, the mechanism of its attenuation of facet-mediated pain has not been evaluated. Protease-activated receptor-1 (PAR1) has differential roles in pain maintenance depending on the type and location of painful injury. This study investigated if the timing of intra-articular ketorolac injection after painful cervical facet injury affects behavioral hypersensitivity by modulating spinal astrocyte activation and/or PAR1 expression. Rats underwent a painful joint distraction and received an injection of ketorolac either immediately or 1 day later. Separate control groups included injured rats with a vehicle injection at day 1 and sham operated rats. Forepaw mechanical allodynia was measured for 7 days, and spinal cord tissue was immunolabeled for glial fibrillary acidic protein (GFAP) and PAR1 expression in the dorsal horn on day 7. Ketorolac administered on day 1 after injury significantly reduced allodynia (p=0.0006) to sham levels, whereas injection immediately after the injury had no effect compared with vehicle. Spinal astrocytic activation followed behavioral responses and was significantly decreased (p=0.009) only for ketorolac given at day 1. Spinal PAR1 (p=0.0025) and astrocytic PAR1 (p=0.012) were significantly increased after injury. Paralleling behavioral data, astrocytic PAR1 was returned to levels in sham only when ketorolac was administered on day 1. Yet, spinal PAR1 was significantly reduced (p<0.0001) by ketorolac independent of timing. Spinal astrocyte expression of PAR1 appears to be associated with the maintenance of facet-mediated pain.

  9. Surface grain refinement mechanism of SMA490BW steel cross joints by ultrasonic impact treatment

    NASA Astrophysics Data System (ADS)

    He, Bo-lin; Xiong, Lei; Jiang, Ming-ming; Yu, Ying-xia; Li, Li

    2017-04-01

    Ultrasonic impact treatment (UIT) is a postweld technique for improving the fatigue strength of welded joints. This technique makes use of ultrasonic vibration to impact and plastically deform a weld toe and can achieve surface grain refinement of the weld toe, which is considered as the main reason for the improvement of fatigue strength. In this paper, the microstructure of the surface of a treated weld toe was observed by metallographic microscopy and transmission electron microscopy (TEM). The results show that UIT could produce severe plastic deformation on the surface layer of the weld toe and the maximum depth of plastic deformation extended to approximately 260 μm beneath the treated surface. Repeated processing could exacerbate the plastic deformation on the surface layer, resulting in finer grains. We can conclude that the surface grain refinement mechanism of SMA490BW welded joints is related to the high density of dislocation tangles and dislocation walls.

  10. Modulation of joint moments and work in the goat hindlimb with locomotor speed and surface grade

    PubMed Central

    Arnold, Allison S.; Lee, David V.; Biewener, Andrew A.

    2013-01-01

    SUMMARY Goats and other quadrupeds must modulate the work output of their muscles to accommodate the changing mechanical demands associated with locomotion in their natural environments. This study examined which hindlimb joint moments goats use to generate and absorb mechanical energy on level and sloped surfaces over a range of locomotor speeds. Ground reaction forces and the three-dimensional locations of joint markers were recorded as goats walked, trotted and galloped over 0, +15 and −15 deg sloped surfaces. Net joint moments, powers and work were estimated at the goats' hip, knee, ankle and metatarsophalangeal joints throughout the stance phase via inverse dynamics calculations. Differences in locomotor speed on the level, inclined and declined surfaces were characterized and accounted for by fitting regression equations to the joint moment, power and work data plotted versus non-dimensionalized speed. During level locomotion, the net work generated by moments at each of the hindlimb joints was small (less than 0.1 J kg−1 body mass) and did not vary substantially with gait or locomotor speed. During uphill running, by contrast, mechanical energy was generated at the hip, knee and ankle, and the net work at each of these joints increased dramatically with speed (P<0.05). The greatest increases in positive joint work occurred at the hip and ankle. During downhill running, mechanical energy was decreased in two main ways: goats generated larger knee extension moments in the first half of stance, absorbing energy as the knee flexed, and goats generated smaller ankle extension moments in the second half of stance, delivering less energy. The goats' hip extension moment in mid-stance was also diminished, contributing to the decrease in energy. These analyses offer new insight into quadrupedal locomotion, clarifying how the moments generated by hindlimb muscles modulate mechanical energy at different locomotor speeds and grades, as needed to accommodate the

  11. Mapping Chondrocyte Viability, Matrix Glycosaminoglycan, and Water Content on the Surface of a Bovine Metatarsophalangeal Joint

    PubMed Central

    Lin, Yi-Cheng; Hall, Andrew C.; Smith, Innes D. M.; Salter, Donald M.; Simpson, A. Hamish R. W.

    2015-01-01

    Objective The purpose of this study was to determine if there were variations in chondrocyte viability, matrix glycosaminoglycan (GAG), and water content between different areas of the articular surface of a bovine metatarsophalangeal joint, a common and reliable source of articular cartilage for experimental study, which may compromise the validity of using multiple samples from different sites within the joint. Methods Nine fresh cadaveric bovine metatarsophalangeal joints were obtained. From each joint, 16 osteochondral explants were taken from 4 facets, yielding a total of 144 cartilage specimens for evaluation of chondrocyte viability, matrix GAG, and water content. A less invasive method for harvesting osteochondral explants and for processing the biopsy for the assessment of chondrocyte viability was developed, which maintained maximal viability within each cartilage explant. Results There was no significant difference between the 16 biopsy sites from the different areas of the joint surface with respect to chondrocyte viability, matrix GAG and water content. Pooled data of all samples from each joint established the baseline values of chondrocyte viability to be 89.4% ± 3.8%, 94.4% ± 2.2%, and 77.9% ± 7.8%, in the superficial quarter, central half, and deep quarter (with regard to depth from the articular surface), respectively. The matrix GAG content of bovine articular cartilage was 6.06 ± 0.41 μg/mg cartilage, and the cartilage water content was 72.4% ± 1.5%. There were also no significant differences of these 3 variables between the different joints. Conclusion It is thus reasonable to compare biopsies obtained from different sites, as a biopsy from one site would be considered representative of the whole joint. PMID:27047642

  12. High resolution surface coil magnetic resonance imaging of the joints: anatomic correlation.

    PubMed

    Middleton, W D; Macrander, S; Lawson, T L; Kneeland, J B; Cates, J D; Kellman, G M; Carrera, G F; Foley, W D; Jesmanowicz, A; Hyde, J S

    1987-07-01

    Magnetic resonance imaging appears to be a particularly promising approach to the evaluation of articular and periarticular abnormalities. Its ability to produce images in multiple planes directly (without reconstruction) provides a unique advantage over CT for the radiologist when he attempts to interpret the complex three dimensional anatomy of most joints. The inherent contrast resolution of MR is excellent, and with the use of surface coils, spatial resolution is sufficient to permit the identification of the small soft tissue structures in and around joints. Artifacts generated by respiratory and cardiac motion are not a problem in MRI of the joints as they are in MR scanning of the body. Based on all these qualities, we believe that MRI will play an important role in the diagnosis of joint abnormalities.

  13. Surface modification of UHMWPE for use in total joint replacements.

    PubMed

    Zhang, Min; James, Susan P; King, Richard; Beauregard, Guy

    2004-01-01

    To create a hydrophilic, lubricious, more wear-resistant UHMWPE bearing, a novel hyaluronan (HA) derivative and novel UHMWPE-hyaluronan composite were developed. HA was silylated to increase its hydrophobicity and compatibility with UHMWPE. The sily1 HA rapidly diffused into the connected pores of UHMWPE preforms in xylenes solution, and fixed within UHMWPE and on its surface after crosslinking. A micro-composite was obtained after hot-pressing the porous preform. The presence of HA film on the composite surface has been demonstrated through X-Ray photoelectron spectroscopy (XPS) analysis and Toluidine Blue O (TBO) dye assay. The aqueous contact angles of micro-composite samples were significantly lower compared with UHMWPE control samples, and the samples processed with hydrolysis prior to final molding were superior to those processed with hydrolysis after molding.

  14. Analysis of fluid film lubrication in artificial hip joint replacements with surfaces of high elastic modulus.

    PubMed

    Jin, Z M; Dowson, D; Fisher, J

    1997-01-01

    Lubrication mechanisms and contact mechanics have been analysed for total hip joint replacements made from hard bearing surfaces such as metal-on-metal and ceramic-on-ceramic. A similar analysis for ultra-high molecular weight polyethylene (UHMWPE) against a hard bearing surface has also been carried out and used as a reference. The most important factor influencing the predicted lubrication film thickness has been found to be the radial clearance between the ball and the socket. Full fluid film lubrication may be achieved in these hard/hard bearings provided that the surface finish of the bearing surface and the radial clearance are chosen correctly and maintained. Furthermore, there is a close relation between the predicted contact half width and the predicted lubrication film thickness. Therefore, it is important to analyse the contact mechanics in artificial hip joint replacements. Practical considerations of manufacturing these bearing surfaces have also been discussed.

  15. Joint variability of global runoff and global sea surface temperatures

    USGS Publications Warehouse

    McCabe, G.J.; Wolock, D.M.

    2008-01-01

    Global land surface runoff and sea surface temperatures (SST) are analyzed to identify the primary modes of variability of these hydroclimatic data for the period 1905-2002. A monthly water-balance model first is used with global monthly temperature and precipitation data to compute time series of annual gridded runoff for the analysis period. The annual runoff time series data are combined with gridded annual sea surface temperature data, and the combined dataset is subjected to a principal components analysis (PCA) to identify the primary modes of variability. The first three components from the PCA explain 29% of the total variability in the combined runoff/SST dataset. The first component explains 15% of the total variance and primarily represents long-term trends in the data. The long-term trends in SSTs are evident as warming in all of the oceans. The associated long-term trends in runoff suggest increasing flows for parts of North America, South America, Eurasia, and Australia; decreasing runoff is most notable in western Africa. The second principal component explains 9% of the total variance and reflects variability of the El Ni??o-Southern Oscillation (ENSO) and its associated influence on global annual runoff patterns. The third component explains 5% of the total variance and indicates a response of global annual runoff to variability in North Aflantic SSTs. The association between runoff and North Atlantic SSTs may explain an apparent steplike change in runoff that occurred around 1970 for a number of continental regions.

  16. Intra-articular nerve growth factor regulates development, but not maintenance, of injury-induced facet joint pain & spinal neuronal hypersensitivity.

    PubMed

    Kras, J V; Kartha, S; Winkelstein, B A

    2015-11-01

    The objective of the current study is to define whether intra-articular nerve growth factor (NGF), an inflammatory mediator that contributes to osteoarthritic pain, is necessary and sufficient for the development or maintenance of injury-induced facet joint pain and its concomitant spinal neuronal hyperexcitability. Male Holtzman rats underwent painful cervical facet joint distraction (FJD) or sham procedures. Mechanical hyperalgesia was assessed in the forepaws, and NGF expression was quantified in the C6/C7 facet joint. An anti-NGF antibody was administered intra-articularly in additional rats immediately or 1 day following facet distraction or sham procedures to block intra-articular NGF and test its contribution to initiation and/or maintenance of facet joint pain and spinal neuronal hyperexcitability. NGF was injected into the bilateral C6/C7 facet joints in separate rats to determine if NGF alone is sufficient to induce these behavioral and neuronal responses. NGF expression increases in the cervical facet joint in association with behavioral sensitivity after that joint's mechanical injury. Intra-articular application of anti-NGF immediately after a joint distraction prevents the development of both injury-induced pain and hyperexcitability of spinal neurons. Yet, intra-articular anti-NGF applied after pain has developed does not attenuate either behavioral or neuronal hyperexcitability. Intra-articular NGF administered to the facet in naïve rats also induces behavioral hypersensitivity and spinal neuronal hyperexcitability. Findings demonstrate that NGF in the facet joint contributes to the development of injury-induced joint pain. Localized blocking of NGF signaling in the joint may provide potential treatment for joint pain. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  17. Ablating spinal NK1-bearing neurons eliminates the development of pain and reduces spinal neuronal hyperexcitability and inflammation from mechanical joint injury in the rat.

    PubMed

    Weisshaar, Christine L; Winkelstein, Beth A

    2014-04-01

    The facet joint is a common source of pain, especially from mechanical injury. Although chronic pain is associated with altered spinal glial and neuronal responses, the contribution of specific spinal cells to joint pain is not understood. This study used the neurotoxin [Sar(9),Met(O2)(11)]-substance P-saporin (SSP-SAP) to selectively eliminate spinal cells expressing neurokinin-1 receptor (NK1R) in a rat model of painful facet joint injury to determine the role of those spinal neurons in pain from facet injury. Following spinal administration of SSP-SAP or its control (blank-SAP), a cervical facet injury was imposed and behavioral sensitivity was assessed. Spinal extracellular recordings were made on day 7 to classify neurons and quantify evoked firing. Spinal glial activation and interleukin 1αα (IL1α) expression also were evaluated. SSP-SAP prevented the development of mechanical hyperalgesia that is induced by joint injury and reduced NK1R expression and mechanically evoked neuronal firing in the dorsal horn. SSP-SAP also prevented a shift toward wide dynamic range neurons that is seen after injury. Spinal astrocytic activation and interleukin 1α (IL1α) expression were reduced to sham levels with SSP-SAP treatment. These results suggest that spinal NK1R-bearing cells are critical in initiating spinal nociception and inflammation associated with a painful mechanical joint injury. Results demonstrate that cells expressing NK1R in the spinal cord are critical for the development of joint pain, spinal neuroplasticity, and inflammation after trauma to the joint. These findings have utility for understanding mechanisms of joint pain and developing potential targets to treat pain. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.

  18. Development of High Temperature Dissimilar Joint Technology for Fission Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Locci, Ivan E.; Bowman, Cheryl L.; Gabb, Timothy P.

    2009-01-01

    NASA is developing fission surface power (FSP) system technology as a potential option for use on the surface of the moon or Mars. The goal is to design a robust system that takes full advantage of existing materials data bases. One of the key components of the power conversion system is the hot-side Heat Exchanger (HX). One possible design for this heat exchanger requires a joint of the dissimilar metals 316L stainless steel and Inconel 718, which must sustain extended operation at high temperatures. This study compares two joining techniques, brazing and diffusion bonding, in the context of forming the requisite stainless steel to superalloy joint. The microstructures produced by brazing and diffusion bonding, the effect of brazing cycle on the mechanical tensile properties of the alloys, and the strength of several brazed joints will be discussed.

  19. Addition of Vancomycin to Cefazolin Prophylaxis Is Associated With Acute Kidney Injury After Primary Joint Arthroplasty.

    PubMed

    Courtney, P Maxwell; Melnic, Christopher M; Zimmer, Zachary; Anari, Jason; Lee, Gwo-Chin

    2015-07-01

    likely to develop AKI compared with those receiving cefazolin alone (13% versus 8%, p = 0.002). Dual-antibiotic prophylaxis also was associated with greater severity; patients in the dual antibiotic group had higher rates of Grade II and III acute kidney injury (3% versus 0%, p = 0.003). There was no difference in the rate of return to baseline renal function (2 ± 1.4 days versus 3 ± 3.4 days; mean difference, 0.5 days; 95% confidence interval [CI], -0.2 to 1.2 days; p = 0.155). Controlling for confounding variables, dual antibiotic prophylaxis (adjusted odds ratio [OR], 1.82; 95% CI, 1.25-2.64; p = 0.002), ASA class (adjusted OR, 1.64; 95% CI, 1.24-2.17; p = 0.001), and preoperative kidney disease (adjusted OR, 1.81; 95% CI, 1.30-2.52; p = 0.001) were independent risk factors for AKI after primary total joint arthroplasty. Without a clear advantage in reducing surgical site infections, the utility and safety of routine addition of vancomycin to the prophylactic regimen in all patients undergoing primary hip and knee arthroplasty should be avoided. Further prospective studies should look at the efficacy of preoperative MRSA screening, decolonization, and selective use of vancomycin in high-risk patients. Level III, therapeutic study.

  20. [Effects of acupuncture-moxibustion intervention on proprioception in athletes with lateral collateral ligament injury of ankle joint].

    PubMed

    Tang, Wen-Jiang; Jiang, Chui-Gang; Chen, Li-Rong; Pang, Yong; Li, Jie; Huang, Yun

    2013-08-01

    To compare the efficacy differences between acupuncture-moxibustion and physiotherapy interventions in improving proprioception of athletes with lateral collateral ligament injury of the ankle joint. Thirty patients with injured lateral collateral ligament of ankle joint were randomly divided into acupuncture group (n = 15) and physiotherapy group (n = 15). Patients of the acupuncture group were treated by acupuncture and moxibustion stimulation of Qiuxu (GB40), Kunlun (BL 60), Shenmai (BL 62), Jiexi (ST 41), and Ashi-points, etc., and those of the physiotherapy group treated with TDP irradiation of the regional lateral malleolus. The treatment of the two groups was conducted once the other day, 3 times each week, continuously for 8 weeks. Before and after the treatment, the ankle-joint's active and passive repositioning error angles were measured by using a joint angle ruler. The average error angle values of active and passive reposition tests of the injured ankle-joint were 4.98 +/- 1.11 and 4.78 +/- 1.3 before the treatment, and 3.67 +/- 0.58 and 3.51 +/- 0.64 after the treatment, respectively in the acupuncture group, being reduced significantly after the treatment (both P < 0.01). No significant changes of the average error angle values of both active and passive reposition tests of the ankle-joint were found after the treatment in the physiotherapy group (P > 0.05). Comparison between two groups showed that the average error angle, average active and passive reposition angles of the injured ankle in the acupuncture group were evidently lower than those in the physiotherapy group (P < 0.01). Acupuncture and moxibustion can effectively improve the proprioception of the injured lateral collateral ligament of the ankle joint in athletes, which is superior to conventional physiotherapy in the therapeutic effect.

  1. Upper limb joint kinetics of three sitting pivot wheelchair transfer techniques in individuals with spinal cord injury

    PubMed Central

    Kankipati, Padmaja; Boninger, Michael L.; Gagnon, Dany; Cooper, Rory A.; Koontz, Alicia M.

    2015-01-01

    Study design Repeated measures design. Objective This study compared the upper extremity (UE) joint kinetics between three transfer techniques. Setting Research laboratory. Methods Twenty individuals with spinal cord injury performed three transfer techniques from their wheelchair to a level tub bench. Two of the techniques involved a head–hips method with leading hand position close (HH-I) and far (HH-A) from the body, and the third technique with the trunk upright (TU) and hand far from body. Motion analysis equipment recorded upper body movements and force sensors recorded their hand and feet reaction forces during the transfers. Results Several significant differences were found between HH-A and HH-I and TU and HH-I transfers indicating that hand placement was a key factor influencing the UE joint kinetics. Peak resultant hand, elbow, and shoulder joint forces were significantly higher for the HH-A and TU techniques at the trailing arm (P < 0.036) and lower at the leading arm (P < 0.021), compared to the HH-I technique. Conclusion Always trailing with the same arm if using HH-A or TU could predispose that arm to overuse related pain and injuries. Technique training should focus on initial hand placement close to the body followed by the amount of trunk flexion needed to facilitate movement. PMID:25130053

  2. Joint Bayesian inference for near-surface explosion yield

    NASA Astrophysics Data System (ADS)

    Bulaevskaya, V.; Ford, S. R.; Ramirez, A. L.; Rodgers, A. J.

    2016-12-01

    A near-surface explosion generates seismo-acoustic motion that is related to its yield. However, the recorded motion is affected by near-source effects such as depth-of-burial, and propagation-path effects such as variable geology. We incorporate these effects in a forward model relating yield to seismo-acoustic motion, and use Bayesian inference to estimate yield given recordings of the seismo-acoustic wavefield. The Bayesian approach to this inverse problem allows us to obtain the probability distribution of plausible yield values and thus quantify the uncertainty in the yield estimate. Moreover, the sensitivity of the acoustic signal falls as a function of the depth-of-burial, while the opposite relationship holds for the seismic signal. Therefore, using both the acoustic and seismic wavefield data allows us to avoid the trade-offs associated with using only one of these signals alone. In addition, our inference framework allows for correlated features of the same data type (seismic or acoustic) to be incorporated in the estimation of yield in order to make use of as much information from the same waveform as possible. We demonstrate our approach with a historical dataset and a contemporary field experiment.

  3. Neural network committees for finger joint angle estimation from surface EMG signals

    PubMed Central

    Shrirao, Nikhil A; Reddy, Narender P; Kosuri, Durga R

    2009-01-01

    Background In virtual reality (VR) systems, the user's finger and hand positions are sensed and used to control the virtual environments. Direct biocontrol of VR environments using surface electromyography (SEMG) signals may be more synergistic and unconstraining to the user. The purpose of the present investigation was to develop a technique to predict the finger joint angle from the surface EMG measurements of the extensor muscle using neural network models. Methodology SEMG together with the actual joint angle measurements were obtained while the subject was performing flexion-extension rotation of the index finger at three speeds. Several neural networks were trained to predict the joint angle from the parameters extracted from the SEMG signals. The best networks were selected to form six committees. The neural network committees were evaluated using data from new subjects. Results There was hysteresis in the measured SMEG signals during the flexion-extension cycle. However, neural network committees were able to predict the joint angle with reasonable accuracy. RMS errors ranged from 0.085 ± 0.036 for fast speed finger-extension to 0.147 ± 0.026 for slow speed finger extension, and from 0.098 ± 0.023 for the fast speed finger flexion to 0.163 ± 0.054 for slow speed finger flexion. Conclusion Although hysteresis was observed in the measured SEMG signals, the committees of neural networks were able to predict the finger joint angle from SEMG signals. PMID:19154615

  4. INTRA-ARTICULAR NERVE GROWTH FACTOR REGULATES DEVELOPMENT, BUT NOT MAINTENANCE, OF INJURY-INDUCED FACET JOINT PAIN & SPINAL NEURONAL HYPERSENSITIVITY

    PubMed Central

    Kras, Jeffrey V.; Kartha, Sonia; Winkelstein, Beth A.

    2015-01-01

    Objective The objective of the current study is to define whether intra-articular nerve growth factor (NGF), an inflammatory mediator that contributes to osteoarthritic pain, is necessary and sufficient for the development or maintenance of injury-induced facet joint pain and its concomitant spinal neuronal hyperexcitability. Method Male Holtzman rats underwent painful cervical facet joint distraction or sham procedures. Mechanical hyperalgesia was assessed in the forepaws, and NGF expression was quantified in the C6/C7 facet joint. An anti-NGF antibody was administered intra-articularly in additional rats immediately or 1 day following facet distraction or sham procedures to block intra-articular NGF and test its contribution to initiation and/or maintenance of facet joint pain and spinal neuronal hyperexcitability. NGF was injected into the bilateral C6/C7 facet joints in separate rats to determine if NGF alone is sufficient to induce these behavioral and neuronal responses. Results NGF expression increases in the cervical facet joint in association with behavioral sensitivity after that joint’s mechanical injury. Intra-articular application of anti-NGF immediately after a joint distraction prevents the development of both injury-induced pain and hyperexcitability of spinal neurons. Yet, intra-articular anti-NGF applied after pain has developed does not attenuate either behavioral or neuronal hyperexcitability. Intra-articular NGF administered to the facet in naïve rats also induces behavioral hypersensitivity and spinal neuronal hyperexcitability. Conclusion Findings demonstrate that NGF in the facet joint contributes to the development of injury-induced joint pain. Localized blocking of NGF signaling in the joint may provide potential treatment for joint pain. PMID:26521746

  5. Joint Disorders

    MedlinePlus

    A joint is where two or more bones come together, like the knee, hip, elbow, or shoulder. Joints can be damaged by many types of injuries or diseases, including Arthritis - inflammation of a joint. It causes pain, stiffness, and swelling. Over time, ...

  6. Joint laminate degradation assessed by reflected ultrasound from the cartilage surface and osteochondral junction

    NASA Astrophysics Data System (ADS)

    Brown, C. P.; Hughes, S. W.; Crawford, R. W.; Oloyede, A.

    2008-08-01

    The ability to quantify and qualify the progression of joint degeneration is becoming increasingly important in surgery. This paper examines the patterns of relative ultrasound reflection from normal, artificially and naturally degraded cartilage-on-bone, particularly investigating the potential of the ratio of reflection coefficients from the surface and osteochondral junction in distinguishing normal from osteoarthritic tissue. To this end, the reflection coefficients from the articular surface and osteochondral junction of normal cartilage-on-bone samples were calculated and compared to samples after the removal of proteoglycans, disruption of the collagen meshwork, delipidization of the articular surface and mechanical abrasion. Our results show that the large variation across normal and degraded joint samples negates the use of an isolated bone reflection measurement and to a lesser extent, an isolated surface reflection. The relative surface to bone reflections, calculated as a ratio of reflection coefficients, provided a more consistent and statistically significant (p < 0.001) method for distinguishing each type of degradation, especially osteoarthritic degradation, and due to the complementary relationship between surface and bone reflections was found to be an effective method for distinguishing degraded from normal tissue in the osteoarthritic joint, independent of the site of initiation of the osteoarthritic process.

  7. Gender-related differences in lower limb alignment, range of joint motion, and the incidence of sports injuries in Japanese university athletes

    PubMed Central

    Mitani, Yasuhiro

    2017-01-01

    [Purpose] To investigate the gender-related differences in lower limb alignment, range of joint motion, and history of lower limb sports injuries in Japanese university athletes. [Subjects and Methods] The subjects were 224 Japanese university athletes (154 males and 70 females). The quadriceps angle (Q-angle), arch height index, and ranges of internal and external rotation of the hip joints were measured. History of lower limb sports injury was surveyed using a questionnaire. [Results] Females had a significantly higher Q-angle and hip joint internal rotation angle and a significantly lower arch height index than males. The survey revealed that a significantly higher proportion of females had a history of lower limb sports injuries, and that the proportion of those with a history of foot/ankle injuries was particularly high. [Conclusion] These results suggested that females experience more lower limb sports injuries than males, and that a large proportion of these injuries involve the foot/ankle. Reduced lower limb alignment and increased range of joint motion in females may be risk factors for injury because they lead to increased physical stress being exerted on the lower legs during sporting activities. PMID:28210029

  8. Association between eczema and increased fracture and bone or joint injury in adults: a US population-based study.

    PubMed

    Garg, Nitin; Silverberg, Jonathan I

    2015-01-01

    Adults with eczema have multiple risk factors for accidental injury. However, little is known about the risk of injury in adult patients with eczema. To determine whether adult eczema is associated with an increased risk of injury. A prospective questionnaire-based study using the 2012 National Health Interview Survey among a nationally representative sample of 34 500 adults aged 18 to 85 years with a history of eczema in the past 12 months. History of fracture and bone or joint injury (FBJI) and other injury causing limitation. The prevalences of eczema and any injury causing limitation were 7.2% (95% CI, 6.9%-7.6%) and 2.0% (95% CI, 1.9%-2.2%), respectively. An FBJI causing limitation was reported by 1.5% (95% CI, 1.3%-1.7%), while other types of injury causing limitation occurred in 0.6% (95% CI, 0.5%-0.7%). Adults with eczema had higher odds of any injury causing limitation (survey logistic regression adjusted odds ratio [aOR], 1.44; 95% CI, 1.07-1.94), particularly FBJI (aOR, 1.67; 95% CI, 1.21-2.33), in models controlling for sociodemographics, asthma, hay fever, food allergies, and psychiatric and behavioral disorders. The prevalence of FBJI causing limitation increased gradually with age, peaking at 50 to 69 years and decreasing thereafter. Significant interactions were observed between eczema and fatigue or sleep symptoms, such that adults with eczema and fatigue (aOR, 1.59; 95% CI, 1.16-2.19), daytime sleepiness (aOR, 1.81; 95% CI, 1.28-2.55), or insomnia (aOR, 1.74; 95% CI, 1.28-2.37) had higher rates of FBJI compared with those with sleep symptoms and no eczema. Adults with both eczema and psychiatric and behavioral disorders (aOR, 2.15; 95% CI, 1.57-2.93) had higher rates of FBJI compared with those with eczema (aOR, 1.39; 95% CI, 1.19-1.61) or psychiatric and behavioral disorders (aOR, 1.58; 95% CI, 1.36-1.83) alone. The results of this study suggest that eczema in adulthood is a previously unrecognized risk factor for fracture and other injury

  9. The joint use of the tangential electric field and surface Laplacian in EEG classification.

    PubMed

    Carvalhaes, C G; de Barros, J Acacio; Perreau-Guimaraes, M; Suppes, P

    2014-01-01

    We investigate the joint use of the tangential electric field (EF) and the surface Laplacian (SL) derivation as a method to improve the classification of EEG signals. We considered five classification tasks to test the validity of such approach. In all five tasks, the joint use of the components of the EF and the SL outperformed the scalar potential. The smallest effect occurred in the classification of a mental task, wherein the average classification rate was improved by 0.5 standard deviations. The largest effect was obtained in the classification of visual stimuli and corresponded to an improvement of 2.1 standard deviations.

  10. Simultaneous segmentation of the bone and cartilage surfaces of a knee joint in 3D

    NASA Astrophysics Data System (ADS)

    Yin, Y.; Zhang, X.; Anderson, D. D.; Brown, T. D.; Hofwegen, C. Van; Sonka, M.

    2009-02-01

    We present a novel framework for the simultaneous segmentation of multiple interacting surfaces belonging to multiple mutually interacting objects. The method is a non-trivial extension of our previously reported optimal multi-surface segmentation. Considering an example application of knee-cartilage segmentation, the framework consists of the following main steps: 1) Shape model construction: Building a mean shape for each bone of the joint (femur, tibia, patella) from interactively segmented volumetric datasets. Using the resulting mean-shape model - identification of cartilage, non-cartilage, and transition areas on the mean-shape bone model surfaces. 2) Presegmentation: Employment of iterative optimal surface detection method to achieve approximate segmentation of individual bone surfaces. 3) Cross-object surface mapping: Detection of inter-bone equidistant separating sheets to help identify corresponding vertex pairs for all interacting surfaces. 4) Multi-object, multi-surface graph construction and final segmentation: Construction of a single multi-bone, multi-surface graph so that two surfaces (bone and cartilage) with zero and non-zero intervening distances can be detected for each bone of the joint, according to whether or not cartilage can be locally absent or present on the bone. To define inter-object relationships, corresponding vertex pairs identified using the separating sheets were interlinked in the graph. The graph optimization algorithm acted on the entire multiobject, multi-surface graph to yield a globally optimal solution. The segmentation framework was tested on 16 MR-DESS knee-joint datasets from the Osteoarthritis Initiative database. The average signed surface positioning error for the 6 detected surfaces ranged from 0.00 to 0.12 mm. When independently initialized, the signed reproducibility error of bone and cartilage segmentation ranged from 0.00 to 0.26 mm. The results showed that this framework provides robust, accurate, and

  11. Assessing ozone injury to leaves of phaseolus vulgaris (pinto) by surface temperature imaging

    SciTech Connect

    Guralnick, L.J. ); Heath, R.L.; Miller, R. )

    1989-04-01

    Ozone injury to leaves can be assessed several ways, but most involve waiting for the injury to become visible or using destructive chemical methods. Also most methods can not discriminate regions of differential injury. An infra-red thermal imaging system can be used to monitor surface temperature changes, partially mirroring changes in transpiration rate induced by ozone injury. Plants were exposed to various levels of ozone and analyzed by the infra-red image patterns pre- and post-fumigation. Leaves (2 and 24 hr post-fumigation) showed an increased surface temperature even under conditions where visible injury was not apparent. The increase in surface temperature correlated with reductions in transpiration. Under carefully controlled irradiation conditions the infra-red image can be used as a non-destructive method to assess ozone injury.

  12. Distal radioulnar joint instability (Galeazzi type injury) after internal fixation in relation to the radius fracture pattern.

    PubMed

    Korompilias, Anastasios V; Lykissas, Marios G; Kostas-Agnantis, Ioannis P; Beris, Alexandros E; Soucacos, Panayiotis N

    2011-05-01

    The purpose of this study was to classify Galeazzi type injuries and determine the association of residual instability after rigid fixation with the fracture pattern of the shaft of the radius, using a system that is based on anatomic landmarks of the radial shaft. The clinical records of 95 patients (72 men and 23 women) with Galeazzi type injuries requiring open reduction and internal fixation of the fractures were retrospectively reviewed. The mean follow-up was 6.8 years (range, 18 mo to 11 y) after injury. Sixty-nine fractures occurred in the distal third of the radial shaft (type I), 17 fractures were in the middle third (type II), and 9 fractures were in the proximal third of the shaft of the radius (type III). Gross instability of the distal radioulnar joint (DRUJ) was determined intraoperatively by manipulation after radial fixation as compared to the uninjured side. Forty patients had DRUJ instability after internal fixation and were treated with temporary pinning with a K-wire placed transversely proximal to the sigmoid notch. Distal radioulnar joint instability after internal fixation was recorded in 37 type I fractures, 2 type II fractures, and 1 type III fracture. Distal radioulnar joint instability following radial shaft fracture fixation is significantly higher in patients with type I fractures than in patients with type II or type III fractures. The location of the radius fracture can be sufficiently used for preoperative estimation of percentage chance of potential DRUJ instability after fracture fixation. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  13. The Surgical Strategy to Correct the Rotational Imbalance of the Glenohumeral Joint after Brachial Plexus Birth Injury

    PubMed Central

    Bahm, J.

    2016-01-01

    In upper brachial plexus birth injury, rotational balance of the glenohumeral joint is frequently affected and contracture in medial rotation of the arm develops, due to a severe palsy or insufficient recovery of the lateral rotators. Some of these children present with a severe glenohumeral joint contracture in the first months, although regular physiotherapy has been provided, a condition associated with a posteriorly subdislocated or dislocated humeral head. These conditions should be screened early by a pediatrician or specialized physiotherapist. Both aspects of muscular weakness affecting the lateral rotators and the initial or progressive glenohumeral deformity and/or subdislocation must be identified and treated accordingly, focusing on the reestablishment of joint congruence and strengthening of the lateral rotators to improve rotational balance, thus working against joint dysplasia and loss of motor function of the shoulder in a growing child. Our treatment strategy adapted over the last 20 years to results from retrospective studies, including biomechanical aspects on muscular imbalance and tendon transfers. With this review, we confront our actual concept to recent literature. PMID:28077955

  14. The Surgical Strategy to Correct the Rotational Imbalance of the Glenohumeral Joint after Brachial Plexus Birth Injury.

    PubMed

    Bahm, J

    2016-01-01

    In upper brachial plexus birth injury, rotational balance of the glenohumeral joint is frequently affected and contracture in medial rotation of the arm develops, due to a severe palsy or insufficient recovery of the lateral rotators. Some of these children present with a severe glenohumeral joint contracture in the first months, although regular physiotherapy has been provided, a condition associated with a posteriorly subdislocated or dislocated humeral head. These conditions should be screened early by a pediatrician or specialized physiotherapist. Both aspects of muscular weakness affecting the lateral rotators and the initial or progressive glenohumeral deformity and/or subdislocation must be identified and treated accordingly, focusing on the reestablishment of joint congruence and strengthening of the lateral rotators to improve rotational balance, thus working against joint dysplasia and loss of motor function of the shoulder in a growing child. Our treatment strategy adapted over the last 20 years to results from retrospective studies, including biomechanical aspects on muscular imbalance and tendon transfers. With this review, we confront our actual concept to recent literature.

  15. Joint loads resulting in ACL rupture: Effects of age, sex, and body mass on injury load and mode of failure in a mouse model.

    PubMed

    Blaker, Carina L; Little, Christopher B; Clarke, Elizabeth C

    2016-09-07

    Anterior cruciate ligament (ACL) tears are a common knee injury with a known but poorly understood association with secondary joint injuries and post-traumatic osteoarthritis (OA). Female sex and age are known risk factors for ACL injury but these variables are rarely explored in mouse models of injury. This study aimed to further characterize a non-surgical ACL injury model to determine its clinical relevance across a wider range of mouse specifications. Cadaveric and anesthetized C57BL/6 mice (9-52 weeks of age) underwent joint loading to investigate the effects of age, sex, and body mass on ACL injury mechanisms. The ACL injury load (whole joint load required to rupture the ACL) was measured from force-displacement data, and mode of failure was assessed using micro-dissection and histology. ACL injury load was found to increase with body mass and age (p < 0.001) but age was not significant when controlling for mass. Sex had no effect. In contrast, the mode of ACL failure varied with both age and sex groups. Avulsion fractures (complete or mixed with mid-substance tears) were common in all age groups but the proportion of mixed and mid-substance failures increased with age. Females were more likely than males to have a major avulsion relative to a mid-substance tear (p < 0.01). This data compliments studies in human cadaveric knees, and provides a basis for determining the severity of joint injury relative to a major ACL tear in mice, and for selecting joint loading conditions in future experiments using this model. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

  16. An investigation into the effect of varying joint aperture and nature of surface on pre-splitting

    SciTech Connect

    Tariq, S.M.; Worsey, P.N.

    1996-12-01

    Presplitting is now a universally accepted perimeter control technique in rock excavation. The success of presplitting and the smoothness and integrity of the resulting perimeter is largely dependent on the nature of joints in any given formation. Many facets of jointing have been previously investigated. The results of the effects of joints frequency and spatial positioning were presented by the authors at the ISEE annual meeting last year. This paper includes the results of further research into the mechanism of presplit blasting being carried out at the Rock Mechanics and Explosives Research Center of the University of Missouri-Rolla. The results of experimental model testing carried out in concrete blocks are presented. The research comprised of modeling both closed and open joints between 3/8 inch blastholes loaded with 15-grain per foot PETN detonating cord. The closed joints were (a) simple (rough) machine-cut and (b) surface ground (smooth-matching). The precision ground joints were modeled to simulate tight fractures as found in real rock mass. Precision spacers of varying thicknesses were used to create opening between the joint surfaces. It was found that precision ground joints have no significant effect on the maximum blasthole spacing up to two joints, and act like a continuous medium. This is because ground surfaces provide a relatively perfect match thereby transmitting most of the energy through the joint. However beyond two ground joints, the effects of attenuation is evident and the maximum blasthole spacing has to be reduced to obtain a presplit plane. A simple machine cut joint, on the other hand, has some undulations that results in loss of energy, making it necessary to bring the blastholes closer to achieve a presplit plane (for up to two joints). It was observed that a ground joint with spacer thickness of 0.012 inch behaves like a free surface.

  17. Incorporation of lower neck shear forces to predict facet joint injury risk in low-speed automotive rear impacts.

    PubMed

    Stemper, Brian D; Storvik, Steven G

    2010-06-01

    Lower neck shear force remains a viable candidate for a low-velocity automotive rear-impact injury criterion. Data were previously reported to demonstrate high correlations between the magnitude of lower neck shear force and lower cervical spine facet joint motions. The present study determined the ability of lower neck shear force to predict soft-tissue injury risk in simulated automotive rear impacts. Rear-impact tests were conducted at two velocities and with two seatback orientations using a Hybrid III anthropomorphic test device (ATD) and stock automobile seats from 2007 model year vehicles. Higher velocities and more vertical seatback orientations were associated with higher injury risk based on computational modeling simulations performed in this study. Six cervical spine injury criteria including NIC, Nij, Nkm, LNL, and lower neck shear force and bending moment, increased with impact velocity. NIC, Nij, and shear force were most sensitive to changes in impact velocity. Four metrics, including Nkm, LNL, and lower neck shear force and bending moment, increased for tests with more vertical seatback orientations. Shear force was most sensitive to changes in seatback orientation. Peak values for shear force, NIC, and Nij occurred approximately at the time of head restraint contact for all four test conditions. Therefore, of the six investigated metrics, lower neck shear force was the only metric to demonstrate consistency with regard to injury risk and timing of peak magnitudes. These results demonstrate the ability of lower neck shear force to predict injury risk during low velocity automotive rear impacts and warrant continued investigation into the sensitivity and applicability of this metric for other rear-impact conditions.

  18. [Surface replacement of proximal interphalangeal joints using CapFlex-PIP].

    PubMed

    Schindele, S F; Altwegg, A; Hensler, S

    2017-02-01

    The cementless implantation of the surface replacement CapFlex-PIP enables pain relief, preservation of motion, improves lateral stability and corrects axis deviation in proximal interphalangeal (PIP) joints of patients with primary and secondary PIP osteoarthritis. Painful PIP joints as a result of degenerative or posttraumatic osteoarthritis with restriction of motion. Secondary inflammatory destruction of PIP joints in rheumatoid arthritis with low inflammatory activity and good bone conditions. Destruction of PIP joints with severe bone loss, osseous defects and chronic joint luxation. Joint destruction induced by florid or subacute bacterial arthritis. Skin infections. Dorsal or palmar incision over the affected PIP joint while sparing the peritendinous tissue. Exposure of the proximal phalangeal head and meticulous bone resection. Precontouring of the bone bed for proximal prosthesis. Insertion of the trial prosthesis. Exposure of the distal base and resection in the correct axis. Determination of distal prosthesis size and height of the polyethylene inlay. Insertion of the trial prosthesis without bone protrusion. After clinical and radiological control, implantation of the final prosthesis. Long finger splint, palmar flexor support splint for 2-3 weeks with active mobilization. Then active free mobilization with a twin bandage. After 6 weeks radiological check and free functional mobilization. The active range of motion of 50 patients increased from 43.4° before surgery to 55.9° after 1 year with concomitant pain relief (6.5 to 2.2). In one case revision surgery was required due to traumatic rupture of the radial collateral ligament and four secondary tenolyses were performed.

  19. Joints with the Surface Modification of Alumina by a Thin Layer of Ti + Nb

    NASA Astrophysics Data System (ADS)

    Ksiazek, Marzanna; Tchorz, Adam; Boron, Lukasz

    2014-05-01

    Al2O3/Al/Al2O3 joints were formed by liquid-state bonding of alumina substrates covered with a thin Ti + Nb coating of 900 nm thickness with the use of an Al interlayer of 30 μm at 973 K under a vacuum of 0.2 mPa for 5 min. The bond strength of the joints was examined by a four-point bending test at 295, 373, and 473 K. Optical, scanning, and transmission electron microscopies were applied for detailed characterization of the interface structure and failure characteristics of fractured joint surfaces. The analysis of the results has shown that (i) bonding occurred due to the formation of a reactive interface on the metal side of the joint in the presence of Al3Nb(Ti) precipitates and (ii) modification of Al2O3 by a thin layer of Ti + Nb increases the hardness at the interface and makes it possible to achieve reliable joints working at elevated temperatures.

  20. Understanding the Acute Skin Injury Mechanism Caused by Player-Surface Contact During Soccer

    PubMed Central

    van den Eijnde, Wilbert A.J.; Peppelman, Malou; Lamers, Edwin A.D.; van de Kerkhof, Peter C.M.; van Erp, Piet E.J.

    2014-01-01

    Background: Superficial skin injuries are considered minor, and their incidence is probably underestimated. Insight into the incidence and mechanism of acute skin injury can be helpful in developing suitable preventive measures and safer playing surfaces for soccer and other field sports. Purpose: To gain insight into the incidence and severity of skin injuries related to soccer and to describe the skin injury mechanism due to player-surface contact. Study Design: Systematic review; Level of evidence, 4. Methods: The prevention model by van Mechelen et al (1992) combined with the injury causation model of Bahr and Krosshaug (2005) were used as a framework for the survey to describe the skin injury incidence and mechanism caused by player-surface contact. Results: The reviewed literature showed that common injury reporting methods are mainly based on time lost from participation or the need for medical attention. Because skin abrasions seldom lead to absence or medical attention, they are often not reported. When reported, the incidence of abrasion/laceration injuries varies from 0.8 to 6.1 injuries per 1000 player-hours. Wound assessment techniques such as the Skin Damage Area and Severity Index can be a valuable tool to obtain a more accurate estimation of the incidence and severity of acute skin injuries. Conclusion: The use of protective equipment, a skin lubricant, or wet surface conditions has a positive effect on preventing abrasion-type injuries from artificial turf surfaces. The literature also shows that essential biomechanical information of the sliding event is lacking, such as how energy is transferred to the area of contact. From a clinical and histological perspective, there are strong indications that a sliding-induced skin lesion is caused by mechanical rather than thermal injury to the skin. PMID:26535330

  1. Joint inversion of high-frequency surface waves with fundamental and higher modes

    USGS Publications Warehouse

    Luo, Y.; Xia, J.; Liu, J.; Liu, Q.; Xu, S.

    2007-01-01

    Joint inversion of multimode surface waves for estimating the shear (S)-wave velocity has received much attention in recent years. In this paper, we first analyze sensitivity of phase velocities of multimodes of surface waves for a six-layer earth model, and then we invert surface-wave dispersion curves of the theoretical model and a real-world example. Sensitivity analysis shows that fundamental mode data are more sensitive to the S-wave velocities of shallow layers and are concentrated on a very narrow frequency band, while higher mode data are more sensitive to the parameters of relatively deeper layers and are distributed over a wider frequency band. These properties provide a foundation of using a multimode joint inversion to define S-wave velocities. Inversion results of both synthetic data and a real-world example demonstrate that joint inversion with the damped least-square method and the singular-value decomposition technique to invert high-frequency surface waves with fundamental and higher mode data simultaneously can effectively reduce the ambiguity and improve the accuracy of S-wave velocities. ?? 2007.

  2. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

    SciTech Connect

    Syracuse, E. M.; Maceira, M.; Zhang, H.; Thurber, C. H.

    2015-02-18

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here, we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm.The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks of both volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs datasets indicate that the results of these types of joint inversions must be interpreted carefully.

  3. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

    DOE PAGES

    Syracuse, E. M.; Maceira, M.; Zhang, H.; ...

    2015-02-18

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here, we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm.The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks ofmore » both volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs datasets indicate that the results of these types of joint inversions must be interpreted carefully.« less

  4. Design of a surface replacement prosthesis for the proximal interphalangeal joint.

    PubMed

    Ash, H E; Unsworth, A

    2000-01-01

    A surface replacement finger joint prosthesis was designed specifically for the proximal interphalangeal joint (PIPJ). The two-piece design consisted of a bi-condylar proximal phalangeal head and a conforming bi-concave middle phalangeal base. The bearing surfaces were designed as close to the original anatomy of the PIPJs as possible, using detailed information obtained from a previous anatomical study of 83 PIPJs by the present authors. Four sizes of prosthesis were designed with maximum head diameters of 7, 8, 9 and 10 mm. Fixation of the joint prosthesis was achieved by an interference fit between the stems of semicircular cross-section and the phalangeal bone shafts. The main considerations for the stem designs were the offset from the centre of rotation, angle of inclination, length, and cross-sectional shape and size. It is proposed that the two components will be made from cross-linked polyethylene (XLPE) because it can be injection moulded to produce the complex shapes of the joint prosthesis. In addition, XLPE against itself has shown comparable wear rates with stainless steel against ultra-high molecular weight polyethylene from previous work by Joyce et al.

  5. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

    NASA Astrophysics Data System (ADS)

    Syracuse, E. M.; Maceira, M.; Zhang, H.; Thurber, C. H.

    2015-02-01

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm. The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks of both volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs data sets indicate that the results of these types of joint inversions must be interpreted carefully.

  6. [Nonoperative approach to injuries of the lateral collateral ligament of the ankle joint].

    PubMed

    Kulenović, E

    1993-01-01

    Patients in number of 185 were included in this study. All of them were treated nonoperatively. One group (64 patients) was treated with early mobilization treatment and the other one (121 patients) with three weeks cast immobilization. Checking examination was done twice: 5 weeks and one year after injury. Chi-square test was used for data processing. Patients treated with cast had shorter recovery, but three were not statistical differences. Positive ADS test one year after the injury (I group 4.7%, and II group 2.5%) was considered as poor result and so was functional instability a year after injury (positive Romberg test, I group 12%, and II group 6.6%). Repeated injury was poor result also. In the first group there were 13.33% repeated injuries and in the second 4.95%.

  7. Gender Dimorphic ACL Strain In Response to Combined Dynamic 3D Knee Joint Loading: Implications for ACL Injury Risk

    PubMed Central

    Mizuno, Kiyonori; Andrish, Jack T.; van den Bogert, Antonie J.; McLean, Scott G.

    2009-01-01

    While gender-based differences in knee joint anatomies/laxities are well documented, the potential for them to precipitate gender-dimorphic ACL loading and resultant injury risk has not been considered. To this end, we generated gender-specific models of ACL strain as a function of any six degrees of freedom (6DOF) knee joint load state via a combined cadaveric and analytical approach. Continuously varying joint forces and torques were applied to five male and five female cadaveric specimens and recorded along with synchronous knee flexion and ACL strain data. All data (~10,000 samples) were submitted to specimen-specific regression analyses, affording ACL strain predictions as a function of the combined 6 DOF knee loads. Following individual model verifications, generalized gender-specific models were generated and subjected to 6 DOF external load scenarios consistent with both a clinical examination and a dynamic sports maneuver. The ensuing model-based strain predictions were subsequently examined for gender-based discrepancies. Male and female specimen specific models predicted ACL strain within 0.51% ± 0.10% and 0.52% ± 0.07% of the measured data respectively, and explained more than 75% of the associated variance in each case. Predicted female ACL strains were also significantly larger than respective male values for both of simulated 6 DOF load scenarios. Outcomes suggest that the female ACL will rupture in response to comparatively smaller external load applications. Future work must address the underlying anatomical/laxity contributions to knee joint mechanical and resultant ACL loading, ultimately affording prevention strategies that may cater to individual joint vulnerabilities. PMID:19464897

  8. Underestimated Sacroiliac Joint Lesion on Computed Tomography in Pelvic Open-book Injury: A Case Report

    PubMed Central

    Kim, Weon-Yoo; Jeong, Jae-Jung; Kang, Han-Vit

    2016-01-01

    The classification of anteroposterior compression (APC) injury type is based on using static radiographs, stress radiographs are known as a useful adjunct in classifying type of APC pelvic injuries. According to a recent article, the intraoperative stress examination has led to a change in the treatment plan in more than 25% of patients on 22 patients presumed APC type I (symphyseal diastasis <2.5 cm) injuries. Here authors present a case demonstrating a necessity of intraoperative stress test for excluding concealed posterior ring disruption. PMID:27536644

  9. Boundary lubrication of joints: characterization of surface-active phospholipids found on retrieved implants.

    PubMed

    Gale, Lorne R; Chen, Yi; Hills, Brian A; Crawford, Ross

    2007-06-01

    The identity of the vital active ingredient within synovial fluid (SF)--to which we owe the near frictionless performance of diarthrodial joints--has been the quest of researchers for many years. Initially, hyaluronic acid (HA) was thought to be the lubricant, but it has been shown not to possess the load-bearing ability required within the physiological joint. The glycoprotein fraction of synovial fluid (lubricin) has been shown to have the same lubricating ability as synovial fluid. All or part of this is thought to be due to the surface-active phospholipids (SAPLs) present in lubricin. We characterized the SAPLs adsorbed on the surface of retrieved prostheses which have been implicated as the boundary lubricant. Rinsing fluids collected from the bearing surfaces of 40 prostheses removed from hip and knee revision operations were analyzed using high-performance liquid chromatography (HPLC). SAPLs were detected on all retrieved implants. During the study, 8 different species of phosphatidylcholines were identified. We also determined the relative concentration of each species, which suggested that the unsaturated SAPL species predominate. It is of value to know the identity of the lubricating constituents of SF, not only for the future development of artificial joints, but also in developing cures for several disease processes in which lubrication plays a role.

  10. Effects of surface treatment and joint shape on microtensile bond strength of reattached root dentin segments.

    PubMed

    Liu, Jia; Kawada, Eiji; Oda, Yutaka

    2004-01-01

    An effective bonding technique for reattaching vertical root fracture segments has not yet been established. The purpose of this study was to investigate the effects of surface treatment and joint shape on bond strength of reattached root dentin segments. Microtensile dentin specimens (n=120, cross-sectional area=1.5 mm2) were obtained from 12 bovine teeth roots, and fractured under a tensile force. The segments of each group (n=6) were reattached by a 4-META/MMA-TBB adhesive resin after different treatments (etching or polishing, a 50-microm or 500-microm gap space, butt or wedge joint). The group with a 50-microm gap space and butt joint, which was not etched or polished, served as the control. After 24 hours of storage in 0.9% normal saline solution or thermal cycling (3000 cycles, 4 degrees C and 60 degrees C), the specimens were fractured in a universal testing machine at a crosshead speed of 1.0 mm/min. The microtensile bond strengths (MPa) were recorded. The bonded interface and fractured surface were observed by SEM (original magnification x 1000). The results were analyzed by a 2-way analysis of variance and the Fisher protected least significant difference post-hoc test (alpha=.05). Significantly higher bond strengths (P=.0001) were shown for the nonpolished group (9.78 +/- 4.44 MPa) and the etched group (9.31 +/- 1.23 MPa) than for the polished group (fractured before test). The wedge-shaped joint exhibited the highest bond strength (18.57 +/- 3.40 MPa, P=.0017). SEM observations showed that the penetration of resin tags along the oblique dentinal tubules was within the wedge joint. Etching and oblique tubule orientation contributed to significantly high bond strength of reattached segments to dentin after vertical root fracture.

  11. No association between surface shifts and time-loss overuse injury risk in male professional football.

    PubMed

    Kristenson, Karolina; Bjørneboe, John; Waldén, Markus; Ekstrand, Jan; Andersen, Thor Einar; Hägglund, Martin

    2016-03-01

    To investigate frequent surface shifts and match play on an unaccustomed surface as potential risk factors for injury in Scandinavian male professional football. Prospective cohort study. Thirty two top-division clubs (16 Swedish, 16 Norwegian) were followed during seasons 2010 and 2011. The influence from (1) number of surface shifts (between artificial turf and grass) during five-match sequences, and (2) match play on an unaccustomed surface (other surface than on the home venue) on subsequent overuse injury risk was evaluated with generalized estimating equations (GEE). GEE results are presented with risk ratios and 95% confidence interval (CI). Injury rate was expressed as time loss injuries/1000h, and compared between groups with a rate ratio and 95% CI. No association was found between the number of surface shifts and subsequent overuse injury risk (risk ratio 1.01, 95% CI 0.91-1.12). Furthermore, no difference was seen in subsequent overuse injury risk after match play on unaccustomed compared with accustomed surface (risk ratio 1.04, 95% CI 0.78-1.38). Grass clubs (grass installed at home venue) had a lower match injury rate when playing away matches on artificial turf compared with away matches on grass (rate ratio 0.66, 95% CI 0.40-0.89). This study showed no association between surface shifts or playing matches on an unaccustomed surface and time-loss injury risk in professional football, suggesting that clubs and players can cope with such surface transitions. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  12. Inferior epigastric artery: Surface anatomy, prevention and management of injury.

    PubMed

    Wong, Clare; Merkur, Harry

    2016-04-01

    The anatomical position of the inferior epigastric artery (IEA) subjects it to risk of injury during abdominal procedures that are close to the artery, such as laparoscopic trocar insertion, insertion of intra-abdominal drains, Tenckhoff(®) catheter (peritoneal dialysis catheter) and paracentesis. This article aims to raise the awareness of the anatomical variations of the course of the IEA in relation to abdominal landmarks in order to define a safer zone for laparoscopic ancillary trocar placement. Methods of managing the IEA injury as well as techniques to minimise the risk of injury to the IEA are reviewed and discussed.

  13. Anterior Cruciate Ligament OsteoArthritis Score (ACLOAS): Longitudinal MRI-based whole joint assessment of anterior cruciate ligament injury.

    PubMed

    Roemer, Frank W; Frobell, Richard; Lohmander, L Stefan; Niu, Jingbo; Guermazi, Ali

    2014-05-01

    To develop a whole joint scoring system, the Anterior Cruciate Ligament OsteoArthritis Score (ACLOAS), for magnetic resonance imaging (MRI)-based assessment of acute anterior cruciate ligament (ACL) injury and follow-up of structural sequelae, and to assess its reliability. Baseline and follow-up 1.5 T MRI examinations from 20 patients of the KANON study, a randomized controlled study comparing a surgical and non-surgical treatment strategy, were assessed for up to six longitudinal visits using a novel MRI scoring system incorporating acute structural tissue damage and longitudinal changes including osteoarthritis (OA) features. Joint features assessed were acute osteochondral injury, traumatic and degenerative bone marrow lesions (BMLs), meniscus morphology and extrusion, osteophytes, collateral and cruciate ligaments including ACL graft, Hoffa-synovitis and effusion-synovitis. Cross-sectional (baseline) and longitudinal (all time points and change) intra- and inter-observer reliability was calculated using weighted (w) kappa statistics and overall percent agreement on a compartmental basis (medial tibio-femoral, lateral tibio-femoral, patello-femoral). Altogether 87 time points were evaluated. Intra-observer reliability ranged between 0.52 (baseline, Hoffa-synovitis) and 1.00 (several features), percent agreement between 52% (all time points, Hoffa-synovitis) and 100% (several features). Inter-observer reliability ranged between 0.00 and 1.00, which is explained by low frequency of some of the features. Altogether, 73% of all assessed 142 parameters showed w-kappa values between 0.80 and 1.00 and 92% showed agreement above 80%. ACLOAS allows reliable scoring of acute ACL injury and longitudinal changes. This novel scoring system incorporates features that may be relevant for structural outcome not covered by established OA scoring instruments. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  14. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2015-10-01

    patient will go on to develop this condition. There are no effective screening methods to determine who is at risk. This proposal includes both a...after moderate to severe articular injuries, not every patient will go on to develop this condition. There are no effective screening methods to...articular injuries, not every patient will go on to develop this condition. Currently, there are no effective screening methods to determine who is at risk

  15. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2015-10-01

    every patient will go on to develop this condition. There are no effective screening methods to determine who is at risk. This proposal includes both...discharged soldiers.3 While PTA can occur rapidly after moderate to severe articular injuries, not every patient will go on to develop this condition. There...the mechanism is not well-understood [1, 2, 3]. While PTA can occur rapidly after moderate to severe articular injuries, not every patient will go on

  16. Clinical and MRI considerations in sports-related knee joint cartilage injury and cartilage repair.

    PubMed

    Hughes, Richard J; Houlihan-Burne, David G

    2011-02-01

    Cartilage injuries of the knee occur frequently in professional and amateur athletes and can be associated with severe debilitation and morbidity. They are commonly associated with ligament injuries but also may be frequently isolated. Increasing awareness and advances in magnetic resonance imaging (MRI) have led to increasing diagnosis and recognition of these injuries. Articular cartilage is just 2 to 4 mm thick and is avascular, alymphatic, and aneural. It has a limited capacity for healing, and there has been increasing use of cartilage repair techniques to treat these lesions in the active population. Strategies for cartilage repair include marrow stimulation techniques such as microfracture/drilling, osteochondral grafting, and autologous chondrocyte transplants. MRI is an important tool in the diagnosis and grading of cartilage injury and is useful in the follow-up and monitoring of these repair procedures. It is important for radiologists and clinicians to be aware of the capabilities and limitations of MRI in assessing cartilage injury and to be familiar with common postsurgical appearances to facilitate assessment and follow-up in this population. This article reviews the clinical findings and MRI imaging appearances of cartilage injury. The management options are discussed as well as common postsurgical appearances following the various interventions.

  17. Joint analysis of refractions with surface waves: An inverse solution to the refraction-traveltime problem

    USGS Publications Warehouse

    Ivanov, J.; Miller, R.D.; Xia, J.; Steeples, D.; Park, C.B.

    2006-01-01

    We describe a possible solution to the inverse refraction-traveltime problem (IRTP) that reduces the range of possible solutions (nonuniqueness). This approach uses a reference model, derived from surface-wave shear-wave velocity estimates, as a constraint. The application of the joint analysis of refractions with surface waves (JARS) method provided a more realistic solution than the conventional refraction/tomography methods, which did not benefit from a reference model derived from real data. This confirmed our conclusion that the proposed method is an advancement in the IRTP analysis. The unique basic principles of the JARS method might be applicable to other inverse geophysical problems. ?? 2006 Society of Exploration Geophysicists.

  18. Compartment Syndrome Following Arthroscopic Removal of a Bullet in the Knee Joint after a Low-Velocity Gunshot Injury.

    PubMed

    Keskinbora, Mert; Yalçin, Sercan; Oltulu, İsmail; Erdil, Mehmet Emin; Örmeci, Tuğrul

    2016-03-01

    Gunshot injuries are getting more frequently reported while the civilian (nongovernmental) armament increases in the world. A 42-year-old male patient presented to emergency room of Istanbul Medipol University Hospital due to a low-velocity gunshot injury. We detected one entry point on the posterior aspect of the thigh, just superior to the popliteal groove. No exit wound was detected on his physical examination. There was swelling around the knee and range of motion was limited due to pain and swelling. Neurological and vascular examinations were intact. Following the initial assessment, the vascular examination was confirmed by doppler ultrasonography of the related extremity. There were no signs of compartment syndrome in the preoperative physical examination. A bullet was detected in the knee joint on the initial X-rays. Immediately after releasing the tourniquet, swelling of the anterolateral compartment of the leg and pulse deficiency was detected on foot in the dorsalis pedis artery. Although the arthroscopic removal of intra-articular bullets following gunshot injuries seems to have low morbidity rates, it should always be considered that the articular capsule may have been ruptured and the fluids used during the operation may leak into surrounding tissues and result in compartment syndrome.

  19. Compartment Syndrome Following Arthroscopic Removal of a Bullet in the Knee Joint after a Low-Velocity Gunshot Injury

    PubMed Central

    Yalçin, Sercan; Oltulu, İsmail; Erdil, Mehmet Emin; Örmeci, Tuğrul

    2016-01-01

    Gunshot injuries are getting more frequently reported while the civilian (nongovernmental) armament increases in the world. A 42-year-old male patient presented to emergency room of Istanbul Medipol University Hospital due to a low-velocity gunshot injury. We detected one entry point on the posterior aspect of the thigh, just superior to the popliteal groove. No exit wound was detected on his physical examination. There was swelling around the knee and range of motion was limited due to pain and swelling. Neurological and vascular examinations were intact. Following the initial assessment, the vascular examination was confirmed by doppler ultrasonography of the related extremity. There were no signs of compartment syndrome in the preoperative physical examination. A bullet was detected in the knee joint on the initial X-rays. Immediately after releasing the tourniquet, swelling of the anterolateral compartment of the leg and pulse deficiency was detected on foot in the dorsalis pedis artery. Although the arthroscopic removal of intra-articular bullets following gunshot injuries seems to have low morbidity rates, it should always be considered that the articular capsule may have been ruptured and the fluids used during the operation may leak into surrounding tissues and result in compartment syndrome. PMID:26929809

  20. Design, fabrication and test of graphite/polyimide composite joints and attachments. [spacecraft control surfaces

    NASA Technical Reports Server (NTRS)

    Cushman, J. B.; Mccleskey, S. F.; Ward, S. H.

    1982-01-01

    The design, analysis, and testing performed to develop four types of graphite/polyimide (Gr/PI) bonded and bolted composite joints for lightly loaded control surfaces on advanced space transportation systems that operate at temperatures up to 561 K (550 F) are summarized. Material properties and small specimen tests were conducted to establish design data and to evaluate specific design details. Static discriminator tests were conducted on preliminary designs to verify structural adequacy. Scaled up specimens of the final joint designs, representative of production size requirements, were subjected to a series of static and fatigue tests to evaluate joint strength. Effects of environmental conditioning were determined by testing aged (125 hours at 589 K (600 F)) and thermal cycled (116 K to 589 K (-250 F to 600 F), 125 times) specimens. It is concluded Gr/PI joints can be designed and fabricated to carry the specified loads. Test results also indicate a possible resin loss or degradation of laminates after exposure to 589 K (600 F) for 125 hours.

  1. Evaluation of near-surface stress distributions in dissimilar welded joint by scanning acoustic microscopy.

    PubMed

    Kwak, Dong Ryul; Yoshida, Sanichiro; Sasaki, Tomohiro; Todd, Judith A; Park, Ik Keun

    2016-04-01

    This paper presents the results from a set of experiments designed to ultrasonically measure the near surface stresses distributed within a dissimilar metal welded plate. A scanning acoustic microscope (SAM), with a tone-burst ultrasonic wave frequency of 200 MHz, was used for the measurement of near surface stresses in the dissimilar welded plate between 304 stainless steel and low carbon steel. For quantitative data acquisition such as leaky surface acoustic wave (leaky SAW) velocity measurement, a point focus acoustic lens of frequency 200 MHz was used and the leaky SAW velocities within the specimen were precisely measured. The distributions of the surface acoustic wave velocities change according to the near-surface stresses within the joint. A three dimensional (3D) finite element simulation was carried out to predict numerically the stress distributions and compare with the experimental results. The experiment and FE simulation results for the dissimilar welded plate showed good agreement. This research demonstrates that a combination of FE simulation and ultrasonic stress measurements using SAW velocity distributions appear promising for determining welding residual stresses in dissimilar material joints.

  2. Structural tests and development of a laminar flow control wing surface composite chordwise joint

    NASA Technical Reports Server (NTRS)

    Lineberger, L. B.

    1984-01-01

    The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program beginning in 1976 to develop technologies to improve fuel efficiency. The Lockheed-Georgia Company accomplished under NAS1-16235 Laminar-Flow-Control (LFC) Wing Panel Structural Design and Development (WSSD); design, manufacturing, and testing activities. An in-depth preliminary design of the baseline 1993 LFC wing was accomplished. A surface panel using the Lockheed graphite/epoxy integrated LFC wing box structural concept was designed. The concept was shown by analysis to be structurally efficient and cost effective. Critical details of the surface and surface joint was demonstrated by fabricating and testing complex, concept selection specimens. The Lockheed-Georgia Company accomplishments, Development of LFC Wind Surface Composite Structures (WSCS), are documented. Tests were conducted on two CV2 panels to verify the static tension and fatigue strength of LFC wing surface chordwise joints.

  3. Long-term outcomes of proximal interphalangeal joint surface replacement arthroplasty.

    PubMed

    Murray, Peter M; Linscheid, Ronald L; Cooney, William P; Baker, Vickie; Heckman, Michael G

    2012-06-20

    Surface replacement arthroplasty is a reconstructive alternative for the treatment of pain and deformity due to osteoarthritis and rheumatoid arthritis of the proximal interphalangeal joint of the finger. This retrospective study was performed to examine long-term outcomes of proximal interphalangeal joint prosthetic surface replacement with a proximal cobalt-chromium (CoCr) and distal ultra-high molecular-weight polyethylene component over thirty years at a single institution. Sixty-seven prostheses were implanted in forty-seven patients between 1974 and 2007. The mean duration of follow-up was 8.8 years. There were fifty joints (75%) with osteoarthritis and seventeen (25%) with rheumatoid arthritis. Fifty-six prostheses (84%) were implanted via a dorsal approach, forty-eight (72%) were cemented, and nineteen (28%) were press-fit. Postoperative evaluation, consisting of a clinical history and examination, radiographs, the Short Form-36 (SF-36) and Disabilities of the Arm, Shoulder and Hand (DASH) questionnaires, and a visual analog scale (VAS) pain score, was performed for thirty-six patients. Demographic, surgical, and implant failure data were obtained from the medical charts of eleven patients (sixteen implants) who had died prior to the time of postoperative follow-up. At the time of follow-up, the median total active proximal interphalangeal joint motion was 40°. Eight prostheses had failed, yielding a cumulative incidence of implant failure of 3% at one year, 8% at three years, 11% at five years, and 16% at fifteen through twenty-five years. Prostheses implanted via a volar approach failed more often than those implanted via a dorsal approach (relative risk: 6.59, p = 0.004). The failure rate did not differ significantly between patients with rheumatoid arthritis and those with osteoarthritis (p = 0.17). The median VAS pain score at the time of follow-up was 3 (of a maximum of 100). There were twenty-two complications in fourteen patients, resulting in four

  4. [Precision MRI-based joint surface and cartilage density analysis of the knee joint using rapid water-excitation sequence and semi-automatic segmentation algorithm].

    PubMed

    Heudorfer, L; Hohe, J; Faber, S; Englmeier, K H; Reiser, M; Eckstein, F

    2000-11-01

    The aim of this study was to analyse the precision of three-dimensional joint surface and cartilage thickness measurements in the knee, using a fast, high-resolution water-excitation sequence and a semiautomated segmentation algorithm. The knee joint of 8 healthy volunteers, aged 22 to 29 years, were examined at a resolution of 1.5 mm x 0.31 mm x 0.31 mm, with four sagittal data sets being acquired after repositioning the joint. After semiautomated segmentation with a B-spline Snake algorithm and 3D reconstruction of the patellar, femoral and tibial cartilages, the joint surface areas (triangulation), cartilage volume, and mean and maximum thickness (Euclidean distance transformation) were analysed, independently of the orientation of the sections. The precision (CV%) for the surface areas was 2.1 to 6.6%. The mean cartilage thickness and cartilage volume showed coefficients of 1.9 to 3.5% (except for the femoral condyles), the value for the medial femoral condyle being 9.1%, and for the lateral condyle 6.5%. For maximum thickness, coefficients of between 2.6 and 5.9% were found. In the present study we investigate for the first time the precision of MRI-based joint surface area measurements in the knee, and of cartilage thickness analyses in the femur. Using a selective water-excitation sequence, the acquisition time can be reduced by more than 50%. The poorer precision in the femoral condyles can be attributed to partial volume effects that occur at the edges of the joint surfaces with a sagittal image protocol. Since MRI is non-invasive, it is highly suitable for examination of healthy subjects (generation of individual finite element models, analysis of functional adaptation to mechanical stimulation, measurement of cartilage deformation in vivo) and as a diagnostic tool for follow-up, indication for therapy, and objective evaluation of new therapeutic agents in osteoarthritis.

  5. Association of the type of trauma, occurrence of bone bruise, fracture and joint effusion with the injury to the menisci and ligaments in MRI of knee trauma

    PubMed Central

    Pezeshki, Sina; Vogl, Thomas J.; Pezeshki, Mohammad Zakaria; Daghighi, Mohammad Hossein; Pourisa, Masoud

    2016-01-01

    Summary Background magnetic resonance imaging (MRI) as a noninvasive diagnostic tool may help clinicians in the evaluation of injuries to menisci and ligaments. Purpose this study assessed the associations between type of trauma to knee joint, bone bruise, fracture and pathological joint effusion with injuries to menisci and ligaments of knee joint. Methods we reviewed knee joint MRI of 175 patients aged less than 45 years old who were referred to MRI center of our University. Results statistical analysis showed that tearing of medial meniscus (MM) is significantly more common in sport related trauma (p= 0.045) but tearing of medial collateral ligament (MCL) is significantly more common in non-sport related trauma (p= 0.005). Existence of bone bruise in knee MRI is negatively associated with tearing of medial meniscus (MM) (p=0.004) and positively associated with tearing of anterior cruciate ligament (ACL) (p=0.00047) and medial collateral ligament (MCL) (p = 0.0001). Existence of fracture is associated with decreased risk of the tearing of ACL and MM (p=0.04, p=0.001 respectively). Pathologic joint effusion is significantly more common in ACL and MCL tearing (p=0.0001, p=0.004 respectively). Conclusions as diagnostic clues, bone bruise, fracture and joint effusion may help radiologists for better assessment of injury to menisci and ligaments in MRI of patients with knee trauma. PMID:27331046

  6. Case report of a rare mallet finger injury.

    PubMed

    Cohn, B T; Froimson, A I

    1986-04-01

    Mallet finger injuries are commonly seen in the emergency room and the treatment is usually simple, consisting of extension splinting of the DIP joint. The hyperextension mallet finger is a rare variant. The diagnosis can be made if the fracture fragment involves more than 50% of the joint surface. For this injury splinting is inadequate and open reduction is the treatment of choice.

  7. Surface grafting of artificial joints with a biocompatible polymer for preventing periprosthetic osteolysis

    NASA Astrophysics Data System (ADS)

    Moro, Toru; Takatori, Yoshio; Ishihara, Kazuhiko; Konno, Tomohiro; Takigawa, Yorinobu; Matsushita, Tomiharu; Chung, Ung-Il; Nakamura, Kozo; Kawaguchi, Hiroshi

    2004-11-01

    Periprosthetic osteolysis-bone loss in the vicinity of a prosthesis-is the most serious problem limiting the longevity of artificial joints. It is caused by bone-resorptive responses to wear particles originating from the articulating surface. This study investigated the effects of graft polymerization of our original biocompatible phospholipid polymer 2-methacryloyloxyethyl phosphorylcholine (MPC) onto the polyethylene surface. Mechanical studies using a hip-joint simulator revealed that the MPC grafting markedly decreased the friction and the amount of wear. Osteoclastic bone resorption induced by subperiosteal injection of particles onto mouse calvariae was abolished by the MPC grafting on particles. MPC-grafted particles were shown to be biologically inert by culture systems with respect to phagocytosis and resorptive cytokine secretion by macrophages, subsequent expression of receptor activator of NF-κB ligand in osteoblasts, and osteoclastogenesis from bone marrow cells. From the mechanical and biological advantages, we believe that our approach will make a major improvement in artificial joints by preventing periprosthetic osteolysis.

  8. Incidence of elbow injuries in adolescent baseball players: screening by a low field magnetic resonance imaging system specialized for small joints.

    PubMed

    Okamoto, Yoshikazu; Maehara, Kiyoshi; Kanahori, Tetsuya; Hiyama, Takashi; Kawamura, Takashi; Minami, Manabu

    2016-04-01

    The aim of this preliminary study was to examine the capability of screening for elbow injuries induced by baseball using a low field small joint MRI system. Sixty-two players in the 4th-6th elementary school grades, with ages ranging from 9 to 12 years, participated in this study. Screening for elbow injuries was performed using a low-magnetic-field (0.2-T) magnetic resonance imaging (MRI) system designed for examinations of small joints of the extremities. Gradient-echo coronal, sagittal, and short-tau inversion recovery (STIR) coronal images of the dominant arm used for pitching were obtained to identify medial collateral ligament (MCL) injuries with or without avulsion fracture and osteochondritis dissecans. All 62 examinations were performed successfully, with 26 players (41.9 %) showing positive findings, all being confined to the MCL. No child showed bone damage. All criteria in the MRI evaluation of injuries showed high agreement rates and kappa values between two radiologists. Screening for early detection of elbow injuries in junior Japanese baseball players can be successfully performed using a low-field MRI system specialized for small joints. The percentage of MCL injury without avulsion fracture was unexpectedly high (41.9 %).

  9. Joint Inversion of Magnetotelluric and Surface Wave Data in Anisotropic Media

    NASA Astrophysics Data System (ADS)

    Roux, E.; Moorkamp, M.; Jones, A. G.; Lebedev, S.

    2008-12-01

    Joint inversion of different kind of geophysical datasets can improve the model resolution and has been commonly undertaken with datasets sensitive to the same physical parameter. Our work involves inverting simultaneously for different physical parameters and is built on a joint inversion method originally applied to teleseismic receiver functions and long-period magnetotelluric data. This is a challenging problem since the two datasets are sensitive to different physical parameters (respectively, shear wave velocity and electrical resistivity). A joint inversion using this approach has been applied successfully to recover one-dimensionnal isotropic structure with both synthetic and real datasets from the Slave Craton (Moorkamp et al., 2007). An approximate agreement between geoelectric strike and seismic fast axis direction inferred from shear wave splitting studies has been found in various regions, such as the Great Slave Lake shear zone (Eaton et al., 2004), across the Grenville Orogen (Ji et al., 1996) and the Sao Francisco craton (Padilha et al., 2006). This suggests a common origin is plausible in some situations for both seismic and electrical anisotropy. These observations motivate our attempt to jointly invert seismic and electrical anisotropic parameters. We use magnetotelluric and surface wave datasets, which both provide a good depth resolution. Assuming that seismic and electrical anisotropy have a common origin, we can thus expect superior resolution of azimuthal anisotropy for lithospheric and sub-lithospheric depths combining these two techniques. We examine the capabilities and limitations of this new approach with synthetics datasets and we will apply this new joint inversion of anisotropic parameters to real datasets. The Slave Craton in Northern Canada is of particular interest but other regions will be investigated.

  10. Development Of an Experimental Animal Model For Lower Back Pain By Percutaneous Injury-Induced Lumbar Facet Joint Osteoarthritis

    PubMed Central

    Kim, Jae-Sung; Ahmadinia, Kasra; Li, Xin; Hamilton, John L; Andrews, Steven; Haralampus, Chris A.; Xiao, Guozhi; Sohn, Hong-Moon; You, Jae-Won; Seo, Yo-Seob; Stein, Gary S.; Wijnen, Andre J Van; Kim, Su-Gwan; Im, Hee-Jeong

    2015-01-01

    We report generation and characterization of pain-related behavior in a minimally-invasive facet joint degeneration (FJD) animal model in rats. FJD was produced by a non-open percutaneous puncture-induced injury on the right lumbar FJs at three consecutive levels. Pressure hyperalgesia in the lower back was assessed by measuring the vocalization response to pressure from a force transducer. After hyperalgesia was established, pathological changes in lumbar FJs and alterations of intervertebral foramen size were assessed by histological and imaging analyses. To investigate treatment options for lumber FJ osteoarthritis-induced pain, animals with established hyperalgesia were administered with analgesic drugs, such as morphine, a selective COX-2 inhibitor, a non-steroidal anti-inflammatory drug (NSAID) (ketorolac), or pregabalin. Effects were assessed by behavioral pain responses. One week after percutaneous puncture-induced injury of the lumbar FJs, ipsilateral primary pressure hyperalgesia developed and was maintained for at least 12 weeks without foraminal stenosis. Animals showed decreased spontaneous activity, but no secondary hyperalgesia in the hind paws. Histopathological and microfocus X-ray computed tomography analyses demonstrated that the percutaneous puncture injury resulted in osteoarthritis-like structural changes in the FJs cartilage and subchondral bone. Pressure hyperalgesia was completely reversed by morphine. The administration of celecoxib produced moderate pain reduction with no statistical significance while the administration of ketorolac and pregabalin produced no analgesic effect on FJ osteoarthritis-induced back pain. Our animal model of non-open percutanous puncture-induced injury of the lumbar FJs in rats shows similar characteristics of low back pain produced by human facet arthropathy. PMID:25858171

  11. Biomechanical evaluation of the impact of various facet joint lesions on the primary stability of anterior plate fixation in cervical dislocation injuries: a cadaver study: Laboratory investigation.

    PubMed

    Oberkircher, Ludwig; Born, Sebastian; Struewer, Johannes; Bliemel, Christopher; Buecking, Benjamin; Wack, Christina; Bergmann, Martin; Ruchholtz, Steffen; Krüger, Antonio

    2014-10-01

    Injuries of the subaxial cervical spine including facet joints and posterior ligaments are common. Potential surgical treatments consist of anterior, posterior, or anterior-posterior fixation. Because each approach has its advantages and disadvantages, the best treatment is debated. This biomechanical cadaver study compared the effect of different facet joint injuries on primary stability following anterior plate fixation. Fractures and plate fixation were performed on 15 fresh-frozen intact cervical spines (C3-T1). To simulate a translation-rotation injury in all groups, complete ligament rupture and facet dislocation were simulated by dissecting the entire posterior and anterior ligament complex between C-4 and C-5. In the first group, the facet joints were left intact. In the second group, one facet joint between C-4 and C-5 was removed and the other side was left intact. In the third group, both facet joints between C-4 and C-5 were removed. The authors next performed single-level anterior discectomy and interbody grafting using bone material from the respective thoracic vertebral bodies. An anterior cervical locking plate was used for fixation. Continuous loading was performed using a servohydraulic test bench at 2 N/sec. The mean load failure was measured when the implant failed. In the group in which both facet joints were intact, the mean load failure was 174.6 ± 46.93 N. The mean load failure in the second group where only one facet joint was removed was 127.8 ± 22.83 N. In the group in which both facet joints were removed, the mean load failure was 73.42 ± 32.51 N. There was a significant difference between the first group (both facet joints intact) and the third group (both facet joints removed) (p < 0.05, Kruskal-Wallis test). In this cadaver study, primary stability of anterior plate fixation for dislocation injuries of the subaxial cervical spine was dependent on the presence of the facet joints. If the bone in one or both facet joints is damaged

  12. Joint inversion of apparent resistivity and seismic surface and body wave data

    NASA Astrophysics Data System (ADS)

    Garofalo, Flora; Sauvin, Guillaume; Valentina Socco, Laura; Lecomte, Isabelle

    2013-04-01

    A novel inversion algorithm has been implemented to jointly invert apparent resistivity curves from vertical electric soundings, surface wave dispersion curves, and P-wave travel times. The algorithm works in the case of laterally varying layered sites. Surface wave dispersion curves and P-wave travel times can be extracted from the same seismic dataset and apparent resistivity curves can be obtained from continuous vertical electric sounding acquisition. The inversion scheme is based on a series of local 1D layered models whose unknown parameters are thickness h, S-wave velocity Vs, P-wave velocity Vp, and Resistivity R of each layer. 1D models are linked to surface-wave dispersion curves and apparent resistivity curves through classical 1D forward modelling, while a 2D model is created by interpolating the 1D models and is linked to refracted P-wave hodograms. A priori information can be included in the inversion and a spatial regularization is introduced as a set of constraints between model parameters of adjacent models and layers. Both a priori information and regularization are weighted by covariance matrixes. We show the comparison of individual inversions and joint inversion for a synthetic dataset that presents smooth lateral variations. Performing individual inversions, the poor sensitivity to some model parameters leads to estimation errors up to 62.5 %, whereas for joint inversion the cooperation of different techniques reduces most of the model estimation errors below 5% with few exceptions up to 39 %, with an overall improvement. Even though the final model retrieved by joint inversion is internally consistent and more reliable, the analysis of the results evidences unacceptable values of Vp/Vs ratio for some layers, thus providing negative Poisson's ratio values. To further improve the inversion performances, an additional constraint is added imposing Poisson's ratio in the range 0-0.5. The final results are globally improved by the introduction of

  13. Macroscopic Surface Structures for Polymer-metal Hybrid Joints Manufactured by Laser Based Thermal Joining

    NASA Astrophysics Data System (ADS)

    Schricker, Klaus; Stambke, Martin; Bergmann, Jean Pierre; Bräutigam, Kevin; Henckell, Philipp

    The increasing application of hybrid structures in component design and fabrication allows to constantly enhance the realization of lightweight potentials. Laser-based joining of metals to polymers can obtaina local bonding with high load bearing capability. During the process, the polymer gets molten by the energy input of the laser beam and penetrates into the structure of the metal surface by means of a defined joining pressure. Macroscopic structures on the metal surface, produced by cutting or laser processing, are possible surface treatmentsfor achieving thepolymer-metal joints. The optimal geometry and other key parameters for the macroscopic surface structures are only partially known at present, e.g. a rising structure density causes a higher load capacity. Based on grooves and drilled holes, as referencegeometries, the depth (0.1-0.9 mm), width (0.3-1.1 mm), alignment angle, diameter (1.0mm- 1.5mm), structure density and penetration depth of the molten polymer were correlated to the separation force. The results allow an essential insight into the main effects ofmacroscopic structures on the mechanical joint properties and the material performance of the polymer during the process.

  14. Joint body and surface wave tomography applied to the Toba caldera complex (Indonesia)

    NASA Astrophysics Data System (ADS)

    Jaxybulatov, Kairly; Koulakov, Ivan; Shapiro, Nikolai

    2016-04-01

    We developed a new algorithm for a joint body and surface wave tomography. The algorithm is a modification of the existing LOTOS code (Koulakov, 2009) developed for local earthquake tomography. The input data for the new method are travel times of P and S waves and dispersion curves of Rayleigh and Love waves. The main idea is that the two data types have complementary sensitivities. The body-wave data have good resolution at depth, where we have enough crossing rays between sources and receivers, whereas the surface waves have very good near-surface resolution. The surface wave dispersion curves can be retrieved from the correlations of the ambient seismic noise and in this case the sampled path distribution does not depend on the earthquake sources. The contributions of the two data types to the inversion are controlled by the weighting of the respective equations. One of the clearest cases where such approach may be useful are volcanic systems in subduction zones with their complex magmatic feeding systems that have deep roots in the mantle and intermediate magma chambers in the crust. In these areas, the joint inversion of different types of data helps us to build a comprehensive understanding of the entire system. We apply our algorithm to data collected in the region surrounding the Toba caldera complex (north Sumatra, Indonesia) during two temporary seismic experiments (IRIS, PASSCAL, 1995, GFZ, LAKE TOBA, 2008). We invert 6644 P and 5240 S wave arrivals and ~500 group velocity dispersion curves of Rayleigh and Love waves. We present a series of synthetic tests and real data inversions which show that joint inversion approach gives more reliable results than the separate inversion of two data types. Koulakov, I., LOTOS code for local earthquake tomographic inversion. Benchmarks for testing tomographic algorithms, Bull. seism. Soc. Am., 99(1), 194-214, 2009, doi:10.1785/0120080013

  15. Facial nerve injury following surgery for the treatment of ankylosis of the temporomandibular joint.

    PubMed

    Nogueira, Ricardo Viana Bessa; Vasconcelos, Belmiro Cavalcanti do Egito

    2007-03-01

    The purpose of the present paper was to carry out a longitudinal study of a series of cases in which injury of the facial nerve was observed following surgery for the treatment of temporomandibular ankylosis. The sample was composed of 13 patients, both male and female, in whom 18 surgical approaches were made. A postoperative assessment of the motor function of the facial nerve was made in accordance with the House-Brackmann grading system. All the patients were photographed and assessed at the following postoperative times: 24 hours, one week, one month and three months. The results showed that injury of the facial nerve occurred in 31% of the cases. An increase in the frequency of nerve injury was observed in the cases in which the interpositional arthroplasty technique was employed, as well as the fact that 75% of the patients had undergone at least one surgical intervention prior to the study. After three months all the patients displayed normal function of the facial nerve. The frequency of facial nerve injury is related to the degree of difficulty involved in the surgery determined by the type of ankylosis. The nerve lesions were shown to be of a temporary nature.

  16. Joint Instability and Osteoarthritis

    PubMed Central

    Blalock, Darryl; Miller, Andrew; Tilley, Michael; Wang, Jinxi

    2015-01-01

    Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA). Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA. PMID:25741184

  17. What design factors influence wear behavior at the bearing surfaces in total joint replacements?

    PubMed

    Brown, Thomas D; Bartel, Donald L

    2008-01-01

    Bearing surface wear in total joint replacements arises from local stresses that exceed the mechanical strength of the articulating materials. Because both the tensile/compressive principal stresses and maximum shear stress near the bearing surface increase when contact stresses increase, minimizing contact stresses has been a central design goal, especially in total knees. Wear rates increase with factors such as increased sliding distance in metal-on-polyethylene bearings, or suboptimal fluid film lubrication in the case of hard-on-hard total hip implants. These factors in turn depend directly on implant design. Advanced preclinical assessment technologies such as laboratory physical simulators and finite element analyses have provided means by which the dependence of wear rate on mechanical design factors can be quantified. However, untoward complexities occurring in vivo, such as impingement or third-body challenge, can appreciably compromise wear performance even for implants that are well-designed in terms of bearing surface stress minimization.

  18. [Preparation and biomechanics study of biological artificial knee joint prosthesis with stereo mesh surface in rabbit].

    PubMed

    Liu, Jianhua; Xu, Dongliang; Yu, Shiming; Hu, Junyong; Chen, Jianwei; Lei, Lei; Li, Zhanchun; Zeng, Xianshang

    2009-04-01

    To develop a kind of biological artificial knee joint prosthesis with stereo mesh surface for rabbit, to observe its function after being implanted into rabbit knee joint and to evaluate its biomechanical property. Thirty adult New Zealand rabbits were randomized into experimental and control groups (n=15), total left knee arthroplasty was performed in both groups, no patella replacement was performed. Biological artificial knee joint prosthesis with stereo mesh surface was self-designed. The adjacent 4/5 surface of femur and tibia stem of the prosthesis was covered by stainless steel stereo mesh, the inner surface of femur condyles and tibia plateau was welded with two layers of stainless steel stereo mesh, then the prosthesis underwent biological fixation in the experimental group. Meanwhile, prosthesis having smooth marrow internal stem, femoral condyle and tibial plateau internal surface and sharing the same shape and size with the experimental group were prepared and fixed with bone cement in the control group. The postoperative general condition of animal was observed. At 1, 3 and 6 months after operation, the rabbits were killed for gross observation, X-ray examination was conducted to observe the fixation condition of prosthesis and healing condition, the range of motion (ROM) of knee joints was tested, biomechanics test was carried out and the maximum shear strength of prosthesis bone interface was calculated. In each group, there was 1 rabbit died and new one was added during the second experiment. The others survived till the end of the experiment and crawled normally 7 days after operation. For the excellent and good rate concerning the recovery of ROM of the knee joint at 1, 3 and 6 months after operation, the experimental group was 60%, 80% and 80%, respectively, and the control group was 60%, 80% and 60%, respectively, indicating there were no significant differences between two groups (P > 0.05). For the experimental group, the gross observation

  19. Effect of Plasma Surface Finish on Wettability and Mechanical Properties of SAC305 Solder Joints

    NASA Astrophysics Data System (ADS)

    Kim, Kyoung-Ho; Koike, Junichi; Yoon, Jeong-Won; Yoo, Sehoon

    2016-12-01

    The wetting behavior, interfacial reactions, and mechanical reliability of Sn-Ag-Cu solder on a plasma-coated printed circuit board (PCB) substrate were evaluated under multiple heat-treatments. Conventional organic solderability preservative (OSP) finished PCBs were used as a reference. The plasma process created a dense and highly cross-linked polymer coating on the Cu substrates. The plasma finished samples had higher wetting forces and shorter zero-cross times than those with OSP surface finish. The OSP sample was degraded after sequential multiple heat treatments and reflow processes, whereas the solderability of the plasma finished sample was retained after multiple heat treatments. After the soldering process, similar microstructures were observed at the interfaces of the two solder joints, where the development of intermetallic compounds was observed. From ball shear tests, it was found that the shear force for the plasma substrate was consistently higher than that for the OSP substrate. Deterioration of the OSP surface finish was observed after multiple heat treatments. Overall, the plasma surface finish was superior to the conventional OSP finish with respect to wettability and joint reliability, indicating that it is a suitable material for the fabrication of complex electronic devices.

  20. A new drought index that considers the joint effects of climate and land surface change

    NASA Astrophysics Data System (ADS)

    Liu, Meixian; Xu, Xianli; Xu, Chaohao; Sun, Alexander Y.; Wang, Kelin; Scanlon, Bridget R.; Zhang, Lu

    2017-04-01

    This study proposes a hydrological drought index, the standardized wetness index (SWI), by combining the structure of the Standardized Precipitation-Evapotranspiration Index and actual-evaporation-based residual water-energy ratio, in which actual evaporation is estimated using the Budyko hypothesis. The SWI requires three parameters—precipitation, potential evaporation, and parameter n of a Budyko-type formula. Based on different types of n (fixed or dynamic), SWI can be used to estimate the dryness/wetness resulting from climate change (variability) solely, and from the joint effects of climate and land surface change (variability). Performance of SWI is evaluated using historical droughts and by comparing to the self-calibrated Palmer Drought Severity Index. Results show that SWI effectively captures global droughts. Furthermore, a case study in two catchments with significant land surface modification indicates that the joint effects of climate and land surface have greater impacts on dryness/wetness in the water-limited Wuding catchment than in the energy-limited Poyang catchment.

  1. The surface geometry of inherited joint and fracture trace patterns resulting from active and passive deformation

    NASA Technical Reports Server (NTRS)

    Podwysocki, M. H.; Gold, D. P.

    1974-01-01

    Hypothetical models are considered for detecting subsurface structure from the fracture or joint pattern, which may be influenced by the structure and propagated to the surface. Various patterns of an initially orthogonal fracture grid are modeled according to active and passive deformation mechanisms. In the active periclinal structure with a vertical axis, fracture frequency increased both over the dome and basin, and remained constant with decreasing depth to the structure. For passive periclinal features such as a reef or sand body, fracture frequency is determined by the arc of curvature and showed a reduction over the reefmound and increased over the basin.

  2. RAPID COMMUNICATION: Nanostructured diamond film deposition on curved surfaces of metallic temporomandibular joint implant

    NASA Astrophysics Data System (ADS)

    Fries, Marc D.; Vohra, Yogesh K.

    2002-10-01

    Microwave plasma chemical vapour deposition of nanostructured diamond films was carried out on curved surfaces of Ti-6Al-4V alloy machined to simulate the shape of a temporomandibular joint (TMJ) dental implant. Raman spectroscopy shows that the deposited films are uniform in chemical composition along the radius of curvature of the TMJ condyle. Thin film x-ray diffraction reveals an interfacial carbide layer and nanocrystalline diamond grains in this coating. Nanoindentation hardness measurements show an ultra-hard coating with a hardness value of 60+/-5 GPa averaged over three samples.

  3. High Temperature Stability of Dissimilar Metal Joints in Fission Surface Power Systems

    SciTech Connect

    Locci, Ivan E.; Nesbitt, James A.; Ritzert, Frank J.; Bowman, Cheryl L.

    2007-01-30

    Future generations of power systems for spacecraft and lunar surface systems will likely require a strong dependence on nuclear power. The design of a space nuclear power plant involves integrating together major subsystems with varying material requirements. Refractory alloys are repeatedly considered for major structural components in space power reactor designs because refractory alloys retain their strength at higher temperatures than other classes of metals. The relatively higher mass and lower ductility of the refractory alloys make them less attractive for lower temperature subsystems in the power plant such as the power conversion system. The power conversion system would consist more likely of intermediate temperature Ni-based superalloys. One of many unanswered questions about the use of refractory alloys in a space power plant is how to transition from the use of the structural refractory alloy to more traditional structural alloys. Because deleterious phases can form when complex alloys are joined and operated at elevated temperatures, dissimilar material diffusion analyses of refractory alloys and superalloys are needed to inform designers about options of joint temperature and operational lifetime. Combinations of four superalloys and six refractory alloys were bonded and annealed at 1150 K and 1300 K to examine diffusional interactions in this study. Joints formed through hot pressing and hot isostatic pressing were compared. Results on newer alloys compared favorably to historical data. Diffusional stability is promising for some combinations of Mo-Re alloys and superalloys at 1150 K, but it appears that lower joint temperatures would be required for other refractory alloy couples.

  4. Successful treatment of a guitarist with a finger joint injury using instrument-assisted soft tissue mobilization: a case report.

    PubMed

    Terry Loghmani, M; Bayliss, Amy J; Clayton, Greg; Gundeck, Evelina

    2015-12-01

    Finger injuries are common and can greatly affect a musician's quality of life. A 55-year-old man, who had injured the proximal interphalangeal joint of the left index finger 6 months prior to any intervention, was treated with a manual therapy approach incorporating instrument-assisted soft tissue mobilization (IASTM). Initial examination findings included self-reported pain and functional limitations and physical impairments that significantly impeded his ability to play the acoustic guitar. He was treated once a week for 6 weeks with IASTM, joint mobilization, therapeutic exercise, and ice massage. Additionally, a home exercise program and self-care instructions were provided. The patient gained positive outcomes with improvements in pain (Numerical Pain Rating Scale while playing the guitar: initial 5/10, discharge 1/10) and function (Disability Arm Shoulder Hand Sports-Performing Arts Optional Module: initial 75; discharge 6·25), each reaching a minimum clinically important difference. Importantly, he was able to play the guitar with minimal to no pain as desired. Physical measures also improved, including an immediate gain in finger range of motion with IASTM alone. Manual therapy approaches integrating IASTM may provide an effective conservative treatment strategy for patients with finger/hand conditions in the performing arts and other patient populations.

  5. Successful treatment of a guitarist with a finger joint injury using instrument-assisted soft tissue mobilization: a case report

    PubMed Central

    Terry Loghmani, M.; Bayliss, Amy J.; Clayton, Greg; Gundeck, Evelina

    2015-01-01

    Finger injuries are common and can greatly affect a musician’s quality of life. A 55-year-old man, who had injured the proximal interphalangeal joint of the left index finger 6 months prior to any intervention, was treated with a manual therapy approach incorporating instrument-assisted soft tissue mobilization (IASTM). Initial examination findings included self-reported pain and functional limitations and physical impairments that significantly impeded his ability to play the acoustic guitar. He was treated once a week for 6 weeks with IASTM, joint mobilization, therapeutic exercise, and ice massage. Additionally, a home exercise program and self-care instructions were provided. The patient gained positive outcomes with improvements in pain (Numerical Pain Rating Scale while playing the guitar: initial 5/10, discharge 1/10) and function (Disability Arm Shoulder Hand Sports-Performing Arts Optional Module: initial 75; discharge 6·25), each reaching a minimum clinically important difference. Importantly, he was able to play the guitar with minimal to no pain as desired. Physical measures also improved, including an immediate gain in finger range of motion with IASTM alone. Manual therapy approaches integrating IASTM may provide an effective conservative treatment strategy for patients with finger/hand conditions in the performing arts and other patient populations. PMID:26952165

  6. Joint Inversion of Magnetotelluric and Surface Wave Data in an Anisotropic Earth

    NASA Astrophysics Data System (ADS)

    Roux, E.; Moorkamp, M.; Jones, A.-G.

    2009-04-01

    Joint inversion of different kind of geophysical datasets can improve model resolution and has been commonly undertaken with datasets sensitive to the same physical parameter. Our work involves inverting simultaneously for different physical parameters and is built upon a joint inversion method originally applied to teleseismic receiver functions and long-period magnetotelluric data. This is a challenging problem since the two datasets are sensitive to different physical parameters (respectively, shear wave velocity and electrical resistivity). A joint inversion using this approach has been applied successfully to recover one-dimensional isotropic structure with both synthetic and real datasets from the Slave Craton (Moorkamp et al., 2007). We decided to expand this work to jointly invert surface waves dispersion curves and magnetotelluric data for anisotropic one-dimensional media. Anisotropy can be related to present and past strain in the lithosphere and is a powerful tool for understanding the formation of a geological environment. At lithospheric and sub-lithospheric depths, seismic anisotropy is often explained in terms of aligned crystals of olivine, which is the most abundant mineral in the upper mantle. This preferential alignment below continental lithosphere can be formed by relative motion between plates and the upper asthenospheric mantle or be a frozen-in crystal alignment created at the time of lithosphere formation. The origin of electrical anisotropy is more controversial. An approximate agreement between geoelectric strike and seismic fast axis direction in continental lithosphere has been found in various regions such as the Great Slave Lake shear zone (Eaton et al., 2004), across the Grenville Orogen (Ji et al., 1996) and the Sao Francisco Craton (Padilha et al., 2006). This suggests a common origin is plausible in some situations for both seismic and electrical anisotropy. These observations motivate our attempt to jointly invert seismic and

  7. Engineered Joint Lubrication for OA Prevention and Treatment

    DTIC Science & Technology

    2015-09-01

    joint and related injuries are complex with aspects of tissue structure loss, inflammation and lubrication all playing roles in dysfunction and...small molecule drugs to target inflammation , to create a comprehensive approach for treating the complex joint environment and its dysfunction. The... bathes the joint surface with several molecules that contribute to lubrication, including lubricin4,5, surface-active phospholipids6–8 and HA (ref. 9

  8. Verification of the effect of surface preparation on Hot Isostatic Pressing diffusion bonding joints of CLAM steel

    NASA Astrophysics Data System (ADS)

    Zhao, Yanyun; Li, Chunjing; Huang, Bo; Liu, Shaojun; Huang, Qunying

    2014-12-01

    Hot Isostatic Pressing (HIP) diffusion bonding with CLAM steel is the primary candidate fabrication technique for the first wall (FW) of DFLL-TBM. Surface state is one of the key factors for the joints quality. The effect of surface state prepared with grinder and miller on HIP diffusion bonding joints of CLAM steel was investigated. HIP diffusion bonding was performed at 140 MPa and 1373 K within 3 h. The mechanical properties of the joints were investigated with instrumented Charpy V-notch impact tests and the microstructures of the joints were analyzed with scanning electron microscopy (SEM). The results showed that the milled samples with fine surface roughness were more suitable for CLAM steel HIP diffusion bonding.

  9. Relationship between markers of type II collagen metabolism and tibiofemoral joint space width changes after ACL injury and reconstruction.

    PubMed

    Tourville, Timothy W; Johnson, Robert J; Slauterbeck, James R; Naud, Shelly; Beynnon, Bruce D

    2013-04-01

    Those who suffer anterior cruciate ligament (ACL) disruptions are at increased risk of experiencing posttraumatic osteoarthritis (OA); however, by the time they become symptomatic, irreversible damage has likely occurred. Little is known regarding the physiological changes in articular cartilage that occur after an ACL injury and the onset of OA. To assess whether patient, functional, and clinical outcomes and type II collagen metabolism are associated with abnormal tibiofemoral joint space width (JSW) 4 years after injury and reconstruction. Cohort study; Level of evidence, 2. A total of 35 ACL-injured patients who underwent ACL reconstruction were enrolled soon after injury, as were 32 matched controls. At baseline and 1- and 4-year follow-ups, patient-oriented subjective and objective outcomes and markers of type II collagen metabolism (considered as the ratio of cleavage to synthesis of type II collagen) were evaluated, as were radiographic measurements of JSW changes about the medial and lateral compartments of the knee. ACL-injured patients were divided into normal and abnormal JSW groups. Both ACL-injured groups (normal and abnormal JSW) had an increased ratio of collagen type I and II cleavage product (uC1,2C) to serum procollagen II C-propeptide (sCPII) compared with controls at 1- and 4-year follow-ups. Patients in the ACL group with an abnormal JSW difference had significantly increased cleavage-to-synthesis ratios of type II collagen (assessed as C-terminal cross-linked telopeptide of type II collagen [uCTX-II]/sCPII ratio) compared with controls at 4-year follow-up. ACL-injured patients with an abnormal JSW difference had significantly increased pain and decreased quality of life (Knee Injury and Osteoarthritis Outcome Score [KOOS]) scores than did ACL-injured patients with a normal JSW difference. ACL-injured patients with an abnormal tibiofemoral JSW had diminished quality of life, increased pain, and increased type II collagen uCTX-II/sCPII ratios

  10. Assessment of Knee Joint Injuries with Low Field Strength Magnetic Resonance Imaging.

    PubMed

    Panta, O B; Neupane, N P; Songmen, S; Gurung, G

    2016-05-01

    Magnetic Resonance Imaging is an appropriate screening tool before therapeutic arthroscopy, making diagnostic arthroscopy unnecessary in most patients. This study aims to evaluate the MRI findings in knee injuries and diagnostic value of low Strength MRI for assessing Meniscal and cruciate ligament tear. A cross sectional study was conducted on patients undergoing "Magnetic Resonance Imaging of the Knee" for injuries of the knee and excluded patients undergoing MRI for other causes, poor diagnostic quality MRI and post operative MRI. All patients were interviewed for mechanism of injury and followed up for arthroscopic findings. Statistical analysis was doe using IBM SPSS 20.0. A total of 81 MRIs was included in the study. Arthroscopic finding of only 32 patients could be followed up. Anterior cruciate ligament (ACL) tear was the most common internal ligament tear accounting for 34(42%) of cases followed by medial meniscus tear in 33(40.7%). Twisting 14( 42.4%)was the most common mechanism involved in medial meniscus tear while combined mechanism of injury was most common mechanism for ACL tear 16( 47.05%). The sensitivity of MRI for diagnosis of ACL tear and medial meniscus tear was 96.3% and 94.7% respectively. Specificity for ACL tear was however only 80% and that for medial meniscus tear was 100%. The diagnostic value of MRI for diagnosing internal derangement of knee was high even with a low Tesla (0.3 T) MRI thus emphasizing the role of MRI as a non-invasive alternative to diagnostic arthroscopy.

  11. Crustal structure of North Dakota from joint inversion of surface wave dispersion and teleseismic P-wave reciever functions

    NASA Astrophysics Data System (ADS)

    Walsh, Braden Michael

    Studying and determining crustal structure of the Earth is important for understanding the interior of the Earth. Using methods like receiver functions and surface wave dispersion allows the determination of differences in structure and composition through the crust. Jointly inverting receiver functions and surface wave dispersion reduces the error and over-interpretation of the crustal structure estimation. Receiver functions and surface wave dispersion invert well together because receiver functions are very sensitive to velocity contrasts and vertical travel times, and surface wave dispersion is sensitive to average velocity and insensitive to sharp velocity contrasts. By jointly inverting receiver functions and surface wave dispersion, shear wave velocity profiles can be created to determine the properties of the crustal structure and velocity contrasts. With the use of IRIS Transportable Array stations data throughout the United States, this thesis takes a closer look at the crustal structure of North Dakota through the joint inversion of surface wave dispersion and teleseismic P-wave receiver functions. The receiver functions in North Dakota show shallow sediment effects that affect the joint inversion process. In western North Dakota the Williston basin and in eastern North Dakota the Red River Valley cause ringing effects in the receiver functions. The shallow sediments in North Dakota control and overpower the rest of the crustal signal in the receiver functions, and thus affect the ability of determining the crustal shear wave velocity structure of North Dakota through the joint inversion of receiver functions and surface wave dispersion, thus the use of background geology is necessary.

  12. Effectiveness of surgical reconstruction to restore radiocarpal joint mechanics after scapholunate ligament injury: an in vivo modeling study.

    PubMed

    Johnson, Joshua E; Lee, Phil; McIff, Terence E; Toby, E Bruce; Fischer, Kenneth J

    2013-05-31

    Disruption of the scapholunate ligament can cause a loss of normal scapholunate mechanics and eventually lead to osteoarthritis. Surgical reconstruction attempts to restore scapholunate relationship show improvement in functional outcomes, but postoperative effectiveness in restoring normal radiocarpal mechanics still remains a question. The objective of this study was to investigate the benefits of surgical repair by observing changes in contact mechanics on the cartilage surface before and after surgical treatment. Six patients with unilateral scapholunate dissociation were enrolled in the study, and displacement driven magnetic resonance image-based surface contact modeling was used to investigate normal, injured and postoperative radiocarpal mechanics. Model geometry was acquired from images of wrists taken in a relaxed position. Kinematics were acquired from image registration between the relaxed images, and images taken during functional loading. Results showed a trend for increase in radiocarpal contact parameters with injury. Peak and mean contact pressures significantly decreased after surgery in the radiolunate articulation and there were no significant differences between normal and postoperative wrists. Results indicated that surgical repair improves contact mechanics after injury and that contact mechanics can be surgically restored to be similar to normal. This study provides novel contact mechanics data on the effects of surgical repair after scapholunate ligament injury. With further work, it may be possible to more effectively differentiate between treatments and degenerative changes based on in vivo contact mechanics data. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Comparative study on isokinetic capacity of knee and ankle joints by functional injury

    PubMed Central

    Jeon, Kyoungkyu; Seo, Byoung-Do; Lee, Sang-Ho

    2016-01-01

    [Purpose] To collect basic data for exercise programs designed to enhance functional knee and ankle joint stability based on isokinetic measurement and muscle strength evaluations in normal and impaired functional states. [Subjects and Methods] Twenty-four subjects were randomly assigned to the athlete group and the control group (n = 12 each). Data were collected of isokinetic knee extensor and flexor strength at 60°/sec, 180°/sec, and 240°/sec and ankle plantar and dorsiflexor strength at 30°/sec and 120°/sec. [Results] Significant intergroup differences were observed in peak torque of the right extensors at 60°/sec, 180°/sec, and 240°/sec and the right flexors at 240°/sec. Significant differences were observed in peak torque/body weight in the right extensors at 60°/sec, 180°/sec, and 240°/sec and in the right flexors at 180°/sec and 240°/sec. Significant peak torque differences were noted in the left ankle joint dorsiflexor at 30°/sec and 120°/sec, right plantar flexor at 120°/sec, left plantar flexor at 30°/sec, left dorsiflexor at 30°/sec and 120°/sec, and right dorsiflexor at 120°/sec. [Conclusion] Isokinetic evaluation stimulates muscle contraction at motion-dependent speeds and may contribute to the development of intervention programs to improve knee and ankle joint function and correct lower-extremity instability. PMID:26957768

  14. Comparative study on isokinetic capacity of knee and ankle joints by functional injury.

    PubMed

    Jeon, Kyoungkyu; Seo, Byoung-Do; Lee, Sang-Ho

    2016-01-01

    [Purpose] To collect basic data for exercise programs designed to enhance functional knee and ankle joint stability based on isokinetic measurement and muscle strength evaluations in normal and impaired functional states. [Subjects and Methods] Twenty-four subjects were randomly assigned to the athlete group and the control group (n = 12 each). Data were collected of isokinetic knee extensor and flexor strength at 60°/sec, 180°/sec, and 240°/sec and ankle plantar and dorsiflexor strength at 30°/sec and 120°/sec. [Results] Significant intergroup differences were observed in peak torque of the right extensors at 60°/sec, 180°/sec, and 240°/sec and the right flexors at 240°/sec. Significant differences were observed in peak torque/body weight in the right extensors at 60°/sec, 180°/sec, and 240°/sec and in the right flexors at 180°/sec and 240°/sec. Significant peak torque differences were noted in the left ankle joint dorsiflexor at 30°/sec and 120°/sec, right plantar flexor at 120°/sec, left plantar flexor at 30°/sec, left dorsiflexor at 30°/sec and 120°/sec, and right dorsiflexor at 120°/sec. [Conclusion] Isokinetic evaluation stimulates muscle contraction at motion-dependent speeds and may contribute to the development of intervention programs to improve knee and ankle joint function and correct lower-extremity instability.

  15. Ultrasonic detection technology based on joint robot on composite component with complex surface

    SciTech Connect

    Hao, Juan; Xu, Chunguang; Zhang, Lan

    2014-02-18

    Some components have complex surface, such as the airplane wing and the shell of a pressure vessel etc. The quality of these components determines the reliability and safety of related equipment. Ultrasonic nondestructive detection is one of the main methods used for testing material defects at present. In order to improve the testing precision, the acoustic axis of the ultrasonic transducer should be consistent with the normal direction of the measured points. When we use joint robots, automatic ultrasonic scan along the component surface normal direction can be realized by motion trajectory planning and coordinate transformation etc. In order to express the defects accurately and truly, the robot position and the signal of the ultrasonic transducer should be synchronized.

  16. Joint effects of illumination geometry and object shape in the perception of surface reflectance

    PubMed Central

    Olkkonen, Maria; Brainard, David H

    2011-01-01

    Surface properties provide useful information for identifying objects and interacting with them. Effective utilization of this information, however, requires that the perception of object surface properties be relatively constant across changes in illumination and changes in object shape. Such constancy has been studied separately for changes in these factors. Here we ask whether the separate study of the illumination and shape effects is sufficient, by testing whether joint effects of illumination and shape changes can be predicted from the individual effects in a straightforward manner. We found large interactions between illumination and object shape in their effects on perceived glossiness. In addition, analysis of luminance histogram statistics could not account for the interactions. PMID:23145259

  17. Arthroscopic irrigation of the bovine stifle joint increases cartilage surface friction and decreases superficial zone lubricin.

    PubMed

    Teeple, Erin; Karamchedu, Naga Padmini; Larson, Katherine M; Zhang, Ling; Badger, Gary J; Fleming, Braden C; Jay, Gregory D

    2016-09-06

    The purpose of this study was to determine the effects of arthroscopic irrigation on cartilage superficial zone lubricin and surface friction. Arthroscopic partial meniscectomy is one of the most commonly performed orthopedic surgeries in the United States, but rates of osteoarthritis progression following this procedure are high. The effect of arthroscopic irrigation on articular surface lubrication has not been previously considered as a contributing factor in outcomes after arthroscopy. Fourteen bovine stifle joints were randomized to receive arthroscopic irrigation (n=7) or no treatment (n=7). Full-thickness osteochondral explants from these joints underwent friction testing to measure static and dynamic coefficients of friction. Following mechanical testing, samples were fixed and stained for lubricin. Percent integrated density, a measure of the amount of lubricin in the superficial zone (0-100µm depth), was determined. Static and dynamic coefficients of friction were found to be significantly greater in arthroscopy specimens compared to controls (p=0.02 and p<0.001, respectively). Percent integrated density of lubricin in the superficial zone was significantly lower in arthroscopy specimens compared to controls (p<0.001). Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Functional anatomy of the equine temporomandibular joint: Collagen fiber texture of the articular surfaces.

    PubMed

    Adams, K; Schulz-Kornas, E; Arzi, B; Failing, K; Vogelsberg, J; Staszyk, C

    2016-11-01

    In the last decade, the equine masticatory apparatus has received much attention. Numerous studies have emphasized the importance of the temporomandibular joint (TMJ) in the functional process of mastication. However, ultrastructural and histological data providing a basis for biomechanical and histopathological considerations are not available. The aim of the present study was to analyze the architecture of the collagen fiber apparatus in the articular surfaces of the equine TMJ to reveal typical morphological features indicating biomechanical adaptions. Therefore, the collagen fiber alignment was visualized using the split-line technique in 16 adult warmblood horses without any history of TMJ disorders. Within the central two-thirds of the articular surfaces of the articular tubercle, the articular disc and the mandibular head, split-lines ran in a correspondent rostrocaudal direction. In the lateral and medial aspects of these articular surfaces, the split-line pattern varied, displaying curved arrangements in the articular disc and punctual split-lines in the bony components. Mediolateral orientated split-lines were found in the rostral and caudal border of the articular disc and in the mandibular fossa. The complex movements during the equine chewing cycle are likely assigned to different areas of the TMJ. The split-line pattern of the equine TMJ is indicative of a relative movement of the joint components in a preferential rostrocaudal direction which is consigned to the central aspects of the TMJ. The lateral and medial aspects of the articular surfaces provide split-line patterns that indicate movements particularly around a dorsoventral axis.

  19. Shoe and Field Surface Risk Factors for Acute Lower Extremity Injuries Among Female Youth Soccer Players.

    PubMed

    OʼKane, John W; Gray, Kristen E; Levy, Marni R; Neradilek, Moni; Tencer, Allan F; Polissar, Nayak L; Schiff, Melissa A

    2016-05-01

    To describe acute lower extremity injuries and evaluate extrinsic risk factors in female youth soccer. Nested case-control study. Youth soccer clubs in Seattle, WA. Female soccer players (n = 351) ages 11 to 15 years randomly selected from 4 soccer clubs from which 83% of their players were enrolled with complete follow-up for 92% of players. Injured players were interviewed regarding injury, field surface, shoe type, and position. Uninjured controls, matched on game or practice session, were also interviewed. The association between risk factors and acute lower extremity injury using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI). One hundred seventy-three acute lower extremity injuries occurred involving primarily the ankle (39.3%), knee (24.9%), and thigh (11.0%). Over half (52.9%) recovered within 1 week, whereas 30.2% lasted beyond 2 weeks. During practices, those injured were approximately 3-fold (OR, 2.83; 95% CI, 1.49-5.31) more likely to play on grass than artificial turf and 2.4-fold (95% CI, 1.03-5.96) more likely to wear cleats on grass than other shoe and surface combinations. During games, injured players were 89% (95% CI, 1.03-4.17) more likely to play defender compared with forward. Half of the acute lower extremity injuries affected the ankle or knee. Grass surface and wearing cleats on grass increased training injuries. The majority, 64%, of female youth soccer players' acute injuries involve the ankle and knee and injury prevention strategies in this age group should target these areas. When considering playing surfaces for training, communities and soccer organizations should consider the third-generation artificial turf a safe alternative to grass.

  20. Posterior sternoclavicular joint dislocation with brachiocephalic vein injury: a case report.

    PubMed

    di Mento, Lorenzo; Staletti, Leda; Cavanna, Matteo; Mocchi, Mattia; Berlusconi, Marco

    2015-12-01

    Posterior dislocation of the clavicle is an uncommon injury, usually related to road traffic or contact sports accidents. The close proximity of vital structures in the mediastinum should alert the surgeon avoiding a closed reduction in the emergency setting. A multidisciplinary team of expert surgeons should be involved and a combined procedure performed. Nevertheless, the risk of developing complications is high. We report this case in order to outline one of the potential complications, to discuss appropriate imaging studies and to describe the details of a safe surgical approach. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Knee Injuries

    MedlinePlus

    ... your knee, like keeping it from bending outward. anterior cruciate ligament (ACL): The ACL connects your femur to your ... Injuries Sports and Exercise Safety Osgood-Schlatter Disease Anterior Cruciate Ligament (ACL) Injuries Bones, Muscles, and Joints Meniscus Tears ...

  2. Comparative Study of ENIG and ENEPIG as Surface Finishes for a Sn-Ag-Cu Solder Joint

    NASA Astrophysics Data System (ADS)

    Yoon, Jeong-Won; Noh, Bo-In; Jung, Seung-Boo

    2011-09-01

    Interfacial reactions and joint reliability of Sn-3.0Ag-0.5Cu solder with two different surface finishes, electroless nickel-immersion gold (ENIG) and electroless nickel-electroless palladium-immersion gold (ENEPIG), were evaluated during a reflow process. We first compared the interfacial reactions of the two solder joints and also successfully revealed a connection between the interfacial reaction behavior and mechanical reliability. The Sn-Ag-Cu/ENIG joint exhibited a higher intermetallic compound (IMC) growth rate and a higher consumption rate of the Ni(P) layer than the Sn-Ag-Cu/ENEPIG joint. The presence of the Pd layer in the ENEPIG suppressed the growth of the interfacial IMC layer and the consumption of the Ni(P) layer, resulting in the superior interfacial stability of the solder joint. The shear test results show that the ENIG joint fractured along the interface, exhibiting indications of brittle failure possibly due to the brittle IMC layer. In contrast, the failure of the ENEPIG joint only went through the bulk solder, supporting the idea that the interface is mechanically reliable. The results from this study confirm that the Sn-Ag-Cu/ENEPIG solder joint is mechanically robust and, thus, the combination is a viable option for a Pb-free package system.

  3. Lithological and Surface Geometry Joint Inversions Using Multi-Objective Global Optimization Methods

    NASA Astrophysics Data System (ADS)

    Lelièvre, Peter; Bijani, Rodrigo; Farquharson, Colin

    2016-04-01

    Geologists' interpretations about the Earth typically involve distinct rock units with contacts (interfaces) between them. In contrast, standard minimum-structure geophysical inversions are performed on meshes of space-filling cells (typically prisms or tetrahedra) and recover smoothly varying physical property distributions that are inconsistent with typical geological interpretations. There are several approaches through which mesh-based minimum-structure geophysical inversion can help recover models with some of the desired characteristics. However, a more effective strategy may be to consider two fundamentally different types of inversions: lithological and surface geometry inversions. A major advantage of these two inversion approaches is that joint inversion of multiple types of geophysical data is greatly simplified. In a lithological inversion, the subsurface is discretized into a mesh and each cell contains a particular rock type. A lithological model must be translated to a physical property model before geophysical data simulation. Each lithology may map to discrete property values or there may be some a priori probability density function associated with the mapping. Through this mapping, lithological inverse problems limit the parameter domain and consequently reduce the non-uniqueness from that presented by standard mesh-based inversions that allow physical property values on continuous ranges. Furthermore, joint inversion is greatly simplified because no additional mathematical coupling measure is required in the objective function to link multiple physical property models. In a surface geometry inversion, the model comprises wireframe surfaces representing contacts between rock units. This parameterization is then fully consistent with Earth models built by geologists, which in 3D typically comprise wireframe contact surfaces of tessellated triangles. As for the lithological case, the physical properties of the units lying between the contact

  4. The joint effect of surface microtopography and near-surface structure on microcontact conditions

    SciTech Connect

    McCool, J.I.

    1989-01-01

    Pin-on-disk tests are now complete on all 27 ceramic Phase I specimens. The relationship between measured pin wear and both mean asperity flash temperature and mean real contact stress is examined for the subset of tests that was run at high sliding speed. Fracture indentation tests were completed at the University of Michigan on a second set of 9 ceramic specimens. The last set of nine specimens for indentation testing have been delivered to the University of Michigan. A total of 45 hardened M50 high alloy steel disks have been coated with WC, TiC and TiN and comprehensive surface roughness measurements have been made. A number of 3/8 in. diameter balls have been similarly coated. These balls will serve as the pin element in pin-on-disk tests to be performed at ORNL. Nonlinear curve fits were made to a series of correction factors that account for the presence of a coating in computing the load and area of spherical asperities. The fitted functions have been incorporated into a simulation model for analyzing the behavior of coated asperities. Example calculations are given for a steel substrate with the coating modulus spanning the range from 1/10 to 10 times the substrate modulus. 3 figs., 3 tabs.

  5. Surface curvature of pelvic joints from three laser scanners: separating anatomy from measurement error.

    PubMed

    Villa, Chiara; Gaudio, Daniel; Cattaneo, Cristina; Buckberry, Jo; Wilson, Andrew S; Lynnerup, Niels

    2015-03-01

    Recent studies have reported that quantifying symphyseal and auricular surface curvature changes on 3D models acquired by laser scanners has a potential for age estimation. However, no tests have been carried out to evaluate the repeatability of the results between different laser scanners. 3D models of the two pelvic joints were generated using three laser scanners (Custom, Faro, and Minolta). The surface curvature, the surface area, and the distance between co-registered meshes were investigated. Close results were found for surface areas (differences between 0.3% and 2.4%) and for distance deviations (average <20 μm, SD <200 μm). The curvature values were found to be systematically biased between different laser scanners, but still showing similar trends with increasing phases/scores. Applying a smoothing factor to the 3D models, it was possible to separate anatomy from the measurement error of each instrument, so that similar curvature values could be obtained (p < 0.05) independent of the specific laser scanner.

  6. Adhesive-Bonded Composite Joint Analysis with Delaminated Surface Ply Using Strain-Energy Release Rate

    NASA Technical Reports Server (NTRS)

    Chadegani, Alireza; Yang, Chihdar; Smeltzer, Stanley S. III

    2012-01-01

    This paper presents an analytical model to determine the strain energy release rate due to an interlaminar crack of the surface ply in adhesively bonded composite joints subjected to axial tension. Single-lap shear-joint standard test specimen geometry with thick bondline is followed for model development. The field equations are formulated by using the first-order shear-deformation theory in laminated plates together with kinematics relations and force equilibrium conditions. The stress distributions for the adherends and adhesive are determined after the appropriate boundary and loading conditions are applied and the equations for the field displacements are solved. The system of second-order differential equations is solved to using the symbolic computation tool Maple 9.52 to provide displacements fields. The equivalent forces at the tip of the prescribed interlaminar crack are obtained based on interlaminar stress distributions. The strain energy release rate of the crack is then determined by using the crack closure method. Finite element analyses using the J integral as well as the crack closure method are performed to verify the developed analytical model. It has been shown that the results using the analytical method correlate well with the results from the finite element analyses. An attempt is made to predict the failure loads of the joints based on limited test data from the literature. The effectiveness of the inclusion of bondline thickness is justified when compared with the results obtained from the previous model in which a thin bondline and uniform adhesive stresses through the bondline thickness are assumed.

  7. Adhesive-Bonded Composite Joint Analysis with Delaminated Surface Ply Using Strain-Energy Release Rate

    NASA Technical Reports Server (NTRS)

    Chadegani, Alireza; Yang, Chihdar; Smeltzer, Stanley S. III

    2012-01-01

    This paper presents an analytical model to determine the strain energy release rate due to an interlaminar crack of the surface ply in adhesively bonded composite joints subjected to axial tension. Single-lap shear-joint standard test specimen geometry with thick bondline is followed for model development. The field equations are formulated by using the first-order shear-deformation theory in laminated plates together with kinematics relations and force equilibrium conditions. The stress distributions for the adherends and adhesive are determined after the appropriate boundary and loading conditions are applied and the equations for the field displacements are solved. The system of second-order differential equations is solved to using the symbolic computation tool Maple 9.52 to provide displacements fields. The equivalent forces at the tip of the prescribed interlaminar crack are obtained based on interlaminar stress distributions. The strain energy release rate of the crack is then determined by using the crack closure method. Finite element analyses using the J integral as well as the crack closure method are performed to verify the developed analytical model. It has been shown that the results using the analytical method correlate well with the results from the finite element analyses. An attempt is made to predict the failure loads of the joints based on limited test data from the literature. The effectiveness of the inclusion of bondline thickness is justified when compared with the results obtained from the previous model in which a thin bondline and uniform adhesive stresses through the bondline thickness are assumed.

  8. High Temperature Stability of Dissimilar Metal Joints in Fission Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Locci, Ivan E.; Nesbitt, James A.; Ritzert, Frank J.; Bowman, Cheryl L.

    2007-01-01

    Future generations of power systems for spacecraft and lunar surface systems will likely require a strong dependence on nuclear power. The design of a space nuclear power plant involves integrating together major subsystems with varying materia1 requirements. Refractory alloys are repeatedly considered for major structural components in space power reactor designs because refractory alloys retain their strength at higher temperatures than other classes of metals. The relatively higher mass and lower ductility of the refractory alloys make them less attractive for lower temperature subsystems in the power plant such as the power conversion system. The power conversion system would consist more likely of intermediate temperature Ni-based superalloys. One of many unanswered questions about the use of refractory alloys in a space power plant is how to transition from the use of the structural refractory alloy to more traditional structural alloys. Because deleterious phases can form when complex alloys are joined and operated at elevated temperatures, dissimilar material diffusion analyses of refractory alloys and superalloys are needed to inform designers about options of joint temperature and operational lifetime. Combinations of four superalloys and six refractory alloys were bonded and annealed at 1150 K and 1300 K to examine diffusional interactions in this study. Joints formed through hot pressing and hot isostatic pressing were compared. Results on newer alloys compared favorably to historical data. Diffusional stability is promising for some combinations of Mo-Re alloys and superalloys at 1150 K, but it appears that lower joint temperatures would be required for other refractory alloy couples.

  9. Coronal plane radiographic evaluation of the single TightRope technique in the treatment of acute acromioclavicular joint injury.

    PubMed

    Yi, Young; Kim, Jeong Woo

    2015-10-01

    This study aimed to demonstrate the technical aspects of the single TightRope (Arthrex, Naples, FL, USA) procedure for acute acromioclavicular-coracoclavicular joint dislocation, identify the predictive factors influencing its outcome, and assess and validate the significance of specific radiologic parameters. We reviewed true anteroposterior shoulder radiographs of 62 consecutive patients who had undergone surgical reconstruction using TightRope for an acute acromioclavicular-coracoclavicular injury. All patients were followed up for at least 12 months between October 2009 and March 2012 and were divided into dissociated or nondissociated groups according to their surgical outcome. We measured the clavicle tunnel anteroposterior angle, distal clavicular tunnel placement, and tunnel-to-medial coracoid ratio, and compared the parameters in each group after a satisfactory intraclass correlation coefficient reliability test result. The angles of patients in the dissociated group were more acute compared with the angles of those in the nondissociated group, which were perpendicular, as verified statistically using the paired t test. The difference in the distal clavicular tunnel placement and tunnel-to-medial coracoid ratio between the groups was not significant. Therefore, tunnel placement is not influenced by coracoclavicular dissociation. The clavicle tunnel anteroposterior angle can be used as a predictor of surgical outcome in coracoclavicular augmentation surgery. The surgeon should strive to place a perpendicular hole from the clavicle to the coracoid process for the TightRope fixation to enable a successful reconstruction of the acute acromioclavicular-coracoclavicular injury. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  10. Optical 3D surface digitizing in forensic medicine: 3D documentation of skin and bone injuries.

    PubMed

    Thali, Michael J; Braun, Marcel; Dirnhofer, Richard

    2003-11-26

    Photography process reduces a three-dimensional (3D) wound to a two-dimensional level. If there is a need for a high-resolution 3D dataset of an object, it needs to be three-dimensionally scanned. No-contact optical 3D digitizing surface scanners can be used as a powerful tool for wound and injury-causing instrument analysis in trauma cases. The 3D skin wound and a bone injury documentation using the optical scanner Advanced TOpometric Sensor (ATOS II, GOM International, Switzerland) will be demonstrated using two illustrative cases. Using this 3D optical digitizing method the wounds (the virtual 3D computer model of the skin and the bone injuries) and the virtual 3D model of the injury-causing tool are graphically documented in 3D in real-life size and shape and can be rotated in the CAD program on the computer screen. In addition, the virtual 3D models of the bone injuries and tool can now be compared in a 3D CAD program against one another in virtual space, to see if there are matching areas. Further steps in forensic medicine will be a full 3D surface documentation of the human body and all the forensic relevant injuries using optical 3D scanners.

  11. LIDAR-based outcrop characterisation - joint classification, surface and block size distribution

    NASA Astrophysics Data System (ADS)

    Tanner, David C.; Dietrich, Patrick; Krawczyk, Charlotte M.

    2013-04-01

    Outcrops, in the first instance, only offer at best a 2-2.5D view of the available geological information, such as joints and fractures. In order to study geodynamic processes, it is necessary to calculate true values of, for example, fracture densities and block dimensions. We show how LIDAR-generated point-cloud data of outcrops can be used to delineate such geological surfaces. Our methods do not require the point-set to be meshed; instead we work with the original point cloud, thus avoiding meshing errors. In a first step we decompose the point-cloud into tiny volumes; in each volume we calculate the best fitting plane. An expert can then decide which of the planes are important (in an interactive density pole diagram) and classify them. Actual block surfaces are identified by applying a clustering algorithm to the mini-planes. Subsequently, we calculate the size of these surfaces. Finally we estimate the block size distribution within the outcrop by projecting the block surfaces into the rock volume. To assess the reproducibility of our results we show to which extent they depend on various parameters, such as the resolution of the LIDAR scan and algorithm parameters. In theory the results can be calculated at the site of measurement to ensure the LIDAR scan resolution is sufficient and if necessary rerun the scan with different parameters. We demonstrate our methods with LIDAR data that we produced in a sandstone quarry in Germany. The part of the outcrop which we measured with the LIDAR was out-of-reach for measurements with a geological compass, but our results correlate well with compass measurements from a different outcrop in the same quarry. Three main surfaces could be delineated from the point cloud: the bedding, and two major joint types. The three fabrics are almost orthogonal. Our statistical results suggest that blocks with a volume of several hundred liters can be expected regularly within the quarry. The results can be directly used to

  12. Adaptive dynamic surface control of flexible-joint robots using self-recurrent wavelet neural networks.

    PubMed

    Yoo, Sung Jin; Park, Jin Bae; Choi, Yoon Ho

    2006-12-01

    A new method for the robust control of flexible-joint (FJ) robots with model uncertainties in both robot dynamics and actuator dynamics is proposed. The proposed control system is a combination of the adaptive dynamic surface control (DSC) technique and the self-recurrent wavelet neural network (SRWNN). The adaptive DSC technique provides the ability to overcome the "explosion of complexity" problem in backstepping controllers. The SRWNNs are used to observe the arbitrary model uncertainties of FJ robots, and all their weights are trained online. From the Lyapunov stability analysis, their adaptation laws are induced, and the uniformly ultimately boundedness of all signals in a closed-loop adaptive system is proved. Finally, simulation results for a three-link FJ robot are utilized to validate the good position tracking performance and robustness against payload uncertainties and external disturbances of the proposed control system.

  13. Intra-articular injection of hyaluronic acid for the reduction in joint adhesion formation in a rabbit model of knee injury.

    PubMed

    Wang, Min; Liu, Chao; Xiao, Wei

    2014-07-01

    Our purpose was to evaluate the effectiveness of intra-articular injections of hyaluronic acid (HA) into immobilized joints for reducing rigidity and formation of joint adhesions following surgery and prolonged joint immobilization. Twenty-four New Zealand white rabbits were randomly divided into experimental (n = 12) and control groups (n = 12). A model of knee injury was created in the right hind leg, and external plaster fixation was performed for 8 weeks. The experimental and control groups received weekly intra-articular injections of 0.3 mL HA solution or normal saline, respectively, in the knee joint. The degree of adhesions, range of motion (ROM), and collagen content of the synovium of the knee joint were observed after 8 weeks. At the end of 8 weeks, the experimental compared with control group had significantly higher mean ROM (70.3° ± 11.1° vs. 54.6° ± 11.2°, respectively; P = 0.002) and mean adhesion score. The experimental group compared with the control group had significantly lower mean adhesion score (2.2 ± 0.9 vs. 3.1 ± 0.7, respectively; P = 0.012) and collagen content (32.4 ± 4.7 vs. 39.0 ± 4.2 μg/mg, P = 0.001). In a rabbit model of knee injury, intra-articular injection of HA decreased adhesion formation and collagen content and increased ROM after prolonged immobilization. These results indicate that HA may be clinically useful to prevent adhesions and improve joint mobility in patients who require joint immobilization for up to 8 weeks.

  14. 3D Morphometric Analysis of Normal Sacroiliac Joints: A New Classification of Surface Shape Variation and the Potential Implications in Pain Syndromes.

    PubMed

    Jesse, Mary Kristen; Kleck, Christopher; Williams, Adam; Petersen, Brian; Glueck, Deborah; Lind, Kimberly; Patel, Vikas

    2017-07-01

    Normal sacroiliac (SI) joints vary widely in shape, and it is unclear whether SI joint morphology plays a role in the development of pain. To answer this question, we used 3D-CT surface rendering to image healthy study participants and used the resulting images to develop a classification system for SI joint morphology. In a case-control study comparing health research participants to patients with SI pain, we assessed whether the classification of SI joint morphology was associated with pain. We aimed to define normal variation in area and shape of the synovialized SI joint. We also aimed to determine interactions between joint area and shape and SI pain in men and women. A retrospective cohort study. University hospital tertiary care center. We conducted a retrospective case-control study. We acquired 3D-CT surface rendered images of the SI joint in 223 normal controls and 34 patients with SI pain syndrome. We measured the sacral and iliac surface areas and performed morphologic 3D assessment of both articular surfaces. We classified SI joints into 3 types based on morphology (types one, 2, and 3). We used descriptive statistics to provide a reference standard for normal SI joints. We used multivariate models to assess whether articular surface area differed between study participants with and without SI pain. We also assessed the association between morphology type and the presence of pain. Sacral and iliac surface areas differ by participant gender. Sacral and iliac surface area was associated with SI joint pain in both men (P = 0.0007) and in women (P = 0.02). In women (P = 0.04), but not in men (P = 0.11), joint shape was associated with pain. A retrospective study may create potential for misclassification bias if SI joint symptoms/histories were present but not well-documented in the electronic medical record. A lack of clinical standardization in the pre-procedural assessment of SI joint pain via provocative maneuvers (FABER, etc.) is also a limitation

  15. Proximal interphalangeal joint dimensions for the design of a surface replacement prosthesis.

    PubMed

    Ash, H E; Unsworth, A

    1996-01-01

    The bones from 83 proximal interphalangeal joints (PIPJs) were dissected in order to determine the shape and size of the articular surfaces. The bones were modelled in acrylic dental bone cement and the original bones and replicas were then sectioned and shadowgraphed. Dimensions were taken from these shadowgraphs to be used in the design of a surface replacement prosthesis for the PIPJ. It was found that the bi-condylar heads of the proximal and middle phalanges were circular in the sagittal plane as was the base of the middle phalanx. However, the radius of curvature of the middle phalangeal base was greater than that of the proximal phalangeal head indicating that the PIPJ is not a conforming joint. The alignment of the radial and ulnar condyles of the proximal phalangeal bones was investigated and it was found that the index and middle finger bones tended to have a more prominent ulnar condyle while the ring and little finger bones tended to have a more prominent radial condyle. This was due to a slight difference in diameters of the two condyles. The proximal phalangeal bone lengths L ranged from 29-52 mm, maximum head widths W from 8.5-15.5 mm and maximum diameters D of the best-fit circles to the sagittal profile of the bone head from 6-11 mm. The middle phalangeal bone lengths ranged from 16-35 mm, maximum head widths from 8.5-12 mm and maximum diameters from 5-7.5 mm. The relationships and ratios between these dimensions for the proximal and middle phalanges have been calculated.

  16. Injury patterns of the acromioclavicular ligament complex in acute acromioclavicular joint dislocations: a cross-sectional, fundamental study.

    PubMed

    Maier, Dirk; Jaeger, Martin; Reising, Kilian; Feucht, Matthias J; Südkamp, Norbert P; Izadpanah, Kaywan

    2016-09-06

    Horizontal instability impairs clinical outcome following acute acromioclavicular joint (ACJ) reconstruction and may be caused by insufficient healing of the superior acromioclavicular ligament complex (ACLC). However, characteristics of acute ACLC injuries are poorly understood so far. Purposes of this study were to identify different ACLC tear types, assess type-specific prevalence and determine influencing cofactors. This prospective, cross-sectional study comprised 65 patients with acute-traumatic Rockwood-5 (n = 57) and Rockwood-4 (n = 8) injuries treated operatively by means of mini-open ACJ reduction and hook plate stabilization. Mean age at surgery was 38.2 years (range, 19-57 years). Standardized pre- and intraoperative evaluation included assessment of ACLC tear patterns and cofactors related to the articular disc, the deltoid-trapezoidal (DT) fascia and bony ACJ morphology. Articular disc size was quantified as 0 = absent, 1 = remnant, 2 = meniscoid and 3 = complete. All patients showed complete ruptures of the superior ACLC, which could be assigned to four different tear patterns. Clavicular-sided (AC-1) tears were observed in 46/65 (70.8 %), oblique (AC-2) tears in 12/65 (18.5 %), midportion (AC-3) tears in 3/65 (4.6 %) and acromial-sided (AC-4) tears in 4/65 (6.1 %) of cases. Articular disc size manifestation was significantly (P < .001) more pronounced in patients with AC-1 tears (1.89 ± 0.57) compared to patients with AC-2 tears (0.67 ± 0.89). Other cofactors did not influence ACLC tear patterns. ACLC dislocation with incarceration caused mechanical impediment to anatomical ACJ reduction in 14/65 (21.5 %) of cases including all Rockwood-4 dislocations. Avulsion "in continuity" was a consistent mode of failure of the DT fascia. Type-specific operative strategies enabled anatomical ACLC repair of all observed tear types. Acute ACLC injuries follow distinct tear patterns. There exist clavicular-sided (AC-1

  17. Dysbiosis in Crohn's disease - Joint action of stochastic injuries and focal inflammation in the gut

    PubMed Central

    Buttó, Ludovica F.; Haller, Dirk

    2017-01-01

    ABSTRACT Gut homeostasis involves interrelated biological networks that include the immune system, specialized cells of the epithelium, such as Paneth and goblet cells, as well as triggers derived from the microbiota. Disruption of these homeostatic interactions may lead to the pathogenesis of inflammatory bowel diseases (IBD). To develop more targeted and individual treatments in Crohn's disease and ulcerative colitis, it becomes more and more important to link key mechanisms of the disease pathogenesis to distinct IBD subsets. For the first time, our laboratory demonstrated a causal role of the microbiota for the development of Crohn's disease (CD)-like ileitis, supporting the hypothesis that a non-infectious, dysbiotic microbial ecosystem harbors aggressive traits relevant for the induction of chronic inflammation in the disease-susceptible host (i.e. TNFΔARE mouse model). Despite a growing body of evidence claiming a primary role for Paneth cells in the pathogenesis of ileal CD, we showed in the TNFΔARE mouse model that Paneth cell failure or exhaustion is a secondary event to inflammation. Therefore, additional mechanisms may act synergistically to initialize the development of CD-like pathology. Hereby, we propose a novel hypothesis suggesting that individual development of dysbiotic communities is based on stochastic injury and focal inflammation of the epithelial lining that propagate radially, finally leading to an aggressive microbial milieu. PMID:28102757

  18. Fatigue Life Improvement for Cruciform Welded Joint by Mechanical Surface Treatment using Hammer Peening and UNSM

    NASA Astrophysics Data System (ADS)

    Han, Seung-Ho; Han, Jeong-Woo; Nam, Yong-Yun; Cho, In-Ho

    For the improvement of fatigue strength of welded structures, mechanical post treatments have been applied in various industrial fields and have in most cases been founded to give substantial increases in their fatigue lives. These methods, generally, consist of the modification of weld toe geometry and the introduction of compressive residual stresses. In mechanical surface treatments, e.g. PHP (pneumatic hammer peening) and UNSM (ultrasonic nano-crystal surface modification), the weld profile is modified due to remove or reduce minute crack-like flaws, and compressive residual stresses are also induced. In this study, a pneumatic hammer peening procedure and a UNSM device were introduced, and a quantitative measure of fatigue strength improvement was performed. The fatigue strength at 2 × 106 cycles of hammer-peened and UNSM treated on a non-load carrying cruciform welded joint shows 220 and 260MPa, respectively, which are more than two times higher than that of as-welded specimen. Especially, the surface layer in the vicinity weld toe treated by the UNSM provides nano-crystal structure created by an ultrasonic cold forging and introduces very high welding residual stress in compression.

  19. Joint Traveltime and Waveform Envelope Inversion for Near-surface Imaging

    NASA Astrophysics Data System (ADS)

    Liu, Zhiyang; Zhang, Jie

    2017-03-01

    In the linearized seismic full waveform inversion (FWI), it is well known that a good initial model is needed to avoid cycle-skipping issue, especially when the low-frequency components of data are lacking. To solve the problem, we develop a joint first-arrival traveltime and early arrival envelope inversion method (JTE) to build a good near-surface velocity model with low-wavenumber components. The JTE method combines the robustness of nonlinear traveltime inversion and the low-frequency information embedded in the waveform envelope. In two synthetic experiments, we confirm that traveltime inversion constrains the top near-surface velocity structures tightly, while the envelope inversion recovers the low-wavenumber structures with low-velocity objects or layers. Using the results of JTE as starting models, we find that FWI can produce accurate solutions for complex numerical models. In a real-data example, JTE followed by FWI resolves a near-surface velocity model to improve statics corrections for the subsurface stacking image.

  20. The effects of road-surface conditions, age, and gender on driver-injury severities.

    PubMed

    Morgan, Abigail; Mannering, Fred L

    2011-09-01

    Drivers' adaptation to weather-induced changes in roadway-surface conditions is a complex process that can potentially be influenced by many factors including age and gender. Using a mixed logit analysis, this research assesses the effects that age, gender, and other factors have on crash severities by considering single-vehicle crashes that occurred on dry, wet, and snow/ice-covered roadway surfaces. With an extensive database of single-vehicle crashes from Indiana in 2007 and 2008, estimation results showed that there were substantial differences across age/gender groups under different roadway-surface conditions. For example, for all females and older males, the likelihood of severe injuries increased when crashes occurred on wet or snow/ice surfaces-but for male drivers under 45 years of age, the probability of severe injuries decreased on wet and snow/ice surfaces - relative to dry-surface crashes. This and many other significant differences among age and gender groups suggest that drivers perceive and react to pavement-surface conditions in very different ways, and this has important safety implications. Furthermore, the empirical findings of this study highlight the value of considering subsets of data to unravel the complex relationships within crash-injury severity analysis.

  1. Associations of horse age, joint type, and osteochondral injury with serum and synovial fluid concentrations of type II collagen biomarkers in Thoroughbreds.

    PubMed

    Nicholson, Anne M; Trumble, Troy N; Merritt, Kelly A; Brown, Murray P

    2010-07-01

    To determine the effects of horse age, osteochondral injury, and joint type on a synthesis biomarker and 3 degradative biomarkers of type II collagen in Thoroughbreds. Healthy rested adult (3- to 12-year-old) Thoroughbreds (n = 19), yearling (1- to 2-year-old) Thoroughbreds (40), and Thoroughbred racehorses (2 to 7 years old) undergoing arthroscopic surgery for removal of osteochondral fragments that resulted from training or racing (41). Samples of blood and metacarpophalangeal, metatarsophalangeal, or carpal joint synovial fluid (SF) were collected from all horses. Commercially available assays were used to analyze SF and serum concentrations of type II collagen biomarkers of synthesis (carboxy propeptide of type II collagen [CPII]) and degradation (cross-linked C-telopeptide fragments of type II collagen [CTX II], neoepitope generated by collagenase cleavage of type I and II collagen [C1,2C], and neoepitope generated by collagenase cleavage of type II collagen [C2C]). Osteochondral injury affected concentrations of CPII, CTX II, C1,2C, and C2C in SF, serum, or both, compared with concentrations in healthy adult horses. Compared with adult horses, yearling horses had increased SF or serum concentrations of degradative biomarkers (CTX II, C1,2C, and C2C). Concentrations were higher in carpal than metacarpophalangeal or metatarsophalangeal joints for all biomarkers in osteochondral-injured horses. Variable differences in SF concentrations between joint types were detected in healthy adult and yearling horses. Horse age, osteochondral injury, and joint type all significantly affected type II collagen biomarker concentrations in SF and serum of Thoroughbreds.

  2. Exploring Caregiver Behavior and Knowledge about Unsafe Sleep Surfaces in Infant Injury Death Cases

    ERIC Educational Resources Information Center

    Chu, Tracy; Hackett, Martine; Kaur, Navpreet

    2015-01-01

    Objectives: In the United States, infant deaths due to sleep-related injuries have quadrupled over the past two decades. One of the major risk factors is the placement of an infant to sleep on a surface other than a crib or bassinet. This study examines contextual circumstances and knowledge and behaviors that may contribute to the placement of…

  3. Exploring Caregiver Behavior and Knowledge about Unsafe Sleep Surfaces in Infant Injury Death Cases

    ERIC Educational Resources Information Center

    Chu, Tracy; Hackett, Martine; Kaur, Navpreet

    2015-01-01

    Objectives: In the United States, infant deaths due to sleep-related injuries have quadrupled over the past two decades. One of the major risk factors is the placement of an infant to sleep on a surface other than a crib or bassinet. This study examines contextual circumstances and knowledge and behaviors that may contribute to the placement of…

  4. [Joint prostheses components of warm-forged and surface treated Ti-6Al-7Nb alloy].

    PubMed

    Semlitsch, M; Weber, H; Streicher, R M; Schön, R

    1991-05-01

    In 1978 development of a TiAl alloy with the inert alloying element niobium was initiated. In 1984, the optimal composition was found to be Ti-6Al-7Nb (Protasul-100). This custom-made alloy for implants has the same alpha/beta micro-structure and equally good mechanical properties as Ti-6Al-4V. The corrosion resistance of Ti-6Al-7Nb is better than that of pure titanium and Ti-6Al-4V, due to the very dense and stable passive layer. Since 1985, highly stressed anchoring stems of various hip prosthesis designs have been manufactured from hot-forged Ti-6Al-7Nb/Protasul-100. Polished surfaces of hip, knee or wrist joints made of Ti-6Al-7Nb intended to articulate with polyethylene are surface-treated by the application of a very hard, 3-5 microns thick titanium nitride coating (Tribosul-TiN), or by oxygen diffusion hardening (Tribosul-ODH) to a depth of 30 microns.

  5. Joint inversion of surface wave dispersion and receiver functions for crustal structure in Oklahoma

    NASA Astrophysics Data System (ADS)

    Guo, Hao

    The surge in seismicity in Oklahoma starting in 2008 raises questions about the actual locations of the earthquakes in the upper crust. The key to answering this is an improved crustal model that explains as many observations as possible. Love and Rayleigh wave dispersion, teleseismic P-wave receiver functions and some unique transverse motions observed at distances less than 100 km that are characteristics of rays reverberating in a basin provide data to derive the crustal model. The surface wave dispersion data set consists of over 300,000 Love/Rayleigh phase/group values obtained from ambient noise cross-correlation of BH channels of the 133 Transportable Array (TA) stations of Earthscope to periods as short as 2 seconds. Station coverage is dense enough to perform the tomography on a 25*25 km grid that should be able to image shallow geological structures. In addition, receiver functions were obtained using teleseismic data recorded from 3 US Geological Survey Networks (GS) stations and 6 Oklahoma Seismic Network (OK) stations from 2011 to 2014. The 1-D S-wave velocity models derived by the joint inversion of surface wave dispersion and receiver functions with geological constraints are tested by fitting the independent transverse seismograms. This test also provides constraints on the earthquake depths in relation to the geological structure.

  6. Ligament Injury, Reconstruction and Osteoarthritis

    PubMed Central

    Fleming, Braden C.; Hulstyn, Michael J.; Oksendahl, Heidi L.; Fadale, Paul D.

    2007-01-01

    Purpose of Review The recent literature on the factors that initiate and accelerate the progression of osteoarthritis following ligament injuries and their treatment is reviewed. Recent Findings The ligament-injured joint is at high risk for osteoarthritis. Current conservative (e.g. rehabilitation) and surgical (e.g. reconstruction) treatment options appear not to reduce osteoarthritis following ligament injury. The extent of osteoarthritis does not appear dependent on which joint is affected, or the presence of damage to other tissues within the joint. Mechanical instability is the likely initiator of osteoarthritis in the ligament-injured patient. Summary The mechanism osteoarthritis begins with the injury rendering the joint unstable. The instability increases the sliding between the joint surfaces and reduces the efficiency of the muscles, factors that alter joint contact mechanics. The load distribution in the cartilage and underlying bone is disrupted, causing wear and increasing shear, which eventually leads to the osteochondral degeneration. The catalyst to the mechanical process is the inflammation response induced by the injury and sustained during healing. In contrast, the inflammation could be responsible for onset, while the mechanical factors accelerate progression. The mechanisms leading to osteoarthritis following ligament injury have not been fully established. A better understanding of these mechanisms should lead to alternative surgical, drug, and tissue-engineering treatment options, which could eliminate osteoarthritis in these patients. Progress is being made on all fronts. Considering that osteoarthritis is likely to occur despite current treatment options, the best solution may be prevention. PMID:17710194

  7. Insights on surface wave dispersion and HVSR: Joint analysis via Pareto optimality

    NASA Astrophysics Data System (ADS)

    Giancarlo, Dal Moro

    2010-10-01

    Surface Wave (SW) dispersion and Horizontal-to-Vertical Spectral Ratio (HVSR) are known as tools able to provide possibly complementary information useful to depict the vertical shear-wave velocity profile. Their joint analysis might then be able to overcome the limits which inevitably affect such methodologies when they are singularly considered. When a problem involves the optimization (i.e. the inversion) of two or more objectives, the standard practice is represented by a normalized summation able to account for the typically different nature and magnitude of the considered phenomena (thus objective functions). This way, a single cost function is obtained and the optimization problem is performed through standard solvers. This approach is often problematic not only because of the mathematically and physically inelegant summation of quantities with different magnitudes and units of measurements. The critical point is indeed represented by the inaccurate performances necessarily obtained while dealing with problems characterized by several local minima and the impossibility of a rigorous assessment of the goodness and meaning of the final result. In the present paper joint analysis of both synthetic and field SW dispersion curves and HVSR datasets is performed via the Pareto front analysis. Results show the relevance of Pareto's criterion not only as ranking system to proceed in heuristic optimization (Evolutionary Algorithms) but also as a tool able to provide some insights about the characteristics of the analyzed signals and the overall congruency of data interpretation and inversion. Possible asymmetry of the final Pareto front models is discussed in the light of relative non-uniqueness of the two considered objective functions.

  8. Comparison of regression models for estimation of isometric wrist joint torques using surface electromyography

    PubMed Central

    2011-01-01

    Background Several regression models have been proposed for estimation of isometric joint torque using surface electromyography (SEMG) signals. Common issues related to torque estimation models are degradation of model accuracy with passage of time, electrode displacement, and alteration of limb posture. This work compares the performance of the most commonly used regression models under these circumstances, in order to assist researchers with identifying the most appropriate model for a specific biomedical application. Methods Eleven healthy volunteers participated in this study. A custom-built rig, equipped with a torque sensor, was used to measure isometric torque as each volunteer flexed and extended his wrist. SEMG signals from eight forearm muscles, in addition to wrist joint torque data were gathered during the experiment. Additional data were gathered one hour and twenty-four hours following the completion of the first data gathering session, for the purpose of evaluating the effects of passage of time and electrode displacement on accuracy of models. Acquired SEMG signals were filtered, rectified, normalized and then fed to models for training. Results It was shown that mean adjusted coefficient of determination (Ra2) values decrease between 20%-35% for different models after one hour while altering arm posture decreased mean Ra2 values between 64% to 74% for different models. Conclusions Model estimation accuracy drops significantly with passage of time, electrode displacement, and alteration of limb posture. Therefore model retraining is crucial for preserving estimation accuracy. Data resampling can significantly reduce model training time without losing estimation accuracy. Among the models compared, ordinary least squares linear regression model (OLS) was shown to have high isometric torque estimation accuracy combined with very short training times. PMID:21943179

  9. Histopathological findings, phenotyping of inflammatory cells, and expression of markers of nitritative injury in joint tissue samples from calves after vaccination and intraarticular challenge with Mycoplasma bovis strain 1067

    PubMed Central

    2014-01-01

    Background The pathogenesis of caseonecrotic lesions developing in lungs and joints of calves infected with Mycoplasma bovis is not clear and attempts to prevent M. bovis-induced disease by vaccines have been largely unsuccessful. In this investigation, joint samples from 4 calves, i.e. 2 vaccinated and 2 non-vaccinated, of a vaccination experiment with intraarticular challenge were examined. The aim was to characterize the histopathological findings, the phenotypes of inflammatory cells, the expression of class II major histocompatibility complex (MHC class II) molecules, and the expression of markers for nitritative stress, i.e. inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT), in synovial membrane samples from these calves. Furthermore, the samples were examined for M. bovis antigens including variable surface protein (Vsp) antigens and M. bovis organisms by cultivation techniques. Results The inoculated joints of all 4 calves had caseonecrotic and inflammatory lesions. Necrotic foci were demarcated by phagocytic cells, i.e. macrophages and neutrophilic granulocytes, and by T and B lymphocytes. The presence of M. bovis antigens in necrotic tissue lesions was associated with expression of iNOS and NT by macrophages. Only single macrophages demarcating the necrotic foci were positive for MHC class II. Microbiological results revealed that M. bovis had spread to approximately 27% of the non-inoculated joints. Differences in extent or severity between the lesions in samples from vaccinated and non-vaccinated animals were not seen. Conclusions The results suggest that nitritative injury, as in pneumonic lung tissue of M. bovis-infected calves, is involved in the development of caseonecrotic joint lesions. Only single macrophages were positive for MHC class II indicating down-regulation of antigen-presenting mechanisms possibly caused by local production of iNOS and NO by infiltrating macrophages. PMID:25162202

  10. Injuries to the Collateral Ligaments of the Metacarpophalangeal Joint of the Thumb, Including Simultaneous Combined Thumb Ulnar and Radial Collateral Ligament Injuries, in National Football League Athletes.

    PubMed

    Werner, Brian C; Belkin, Nicole S; Kennelly, Steve; Weiss, Leigh; Barnes, Ronnie P; Rodeo, Scott A; Warren, Russell F; Hotchkiss, Robert N

    2017-01-01

    Thumb collateral ligament injuries occur frequently in the National Football League (NFL). In the general population or in recreational athletes, pure metacarpophalangeal (MCP) abduction or adduction mechanisms yield isolated ulnar collateral ligament (UCL) and radial collateral ligament (RCL) tears, respectively, while NFL athletes may sustain combined mechanism injury patterns. To evaluate the incidence of simultaneous combined thumb UCL and RCL tears among all thumb MCP collateral ligament injuries in NFL athletes on a single team. Case series; Level of evidence, 4. A retrospective review of all thumb injuries on a single NFL team from 1991 to 2014 was performed. All players with a thumb MCP collateral ligament injury were included. Collateral ligament injuries were confirmed by review of both physical examination findings and magnetic resonance imaging. Player demographics, surgical details, and return-to-play data were obtained from the team electronic medical record and surgeons' records. A total of 36 thumbs in 32 NFL players were included in the study, yielding an incidence of 1.6 thumb MCP collateral ligament injuries per year on a single NFL team. Of these, 9 thumbs (25%) had a simultaneous combined UCL and RCL tear injury pattern confirmed on both physical examination and MRI. The remaining 27 thumbs (75%) were isolated UCL injuries. All combined UCL/RCL injuries required surgery due to dysfunction from instability; 63.0% of isolated UCL injuries required surgical repair ( P = .032) due to continued pain and dysfunction from instability. Repair, when required, was delayed until the end of the season. All players with combined UCL/RCL injuries and isolated UCL injuries returned to play professional football the following season. Simultaneous combined thumb UCL and RCL tear is a previously undescribed injury pattern that occurred in 25% of thumb MCP collateral ligament injuries on a single NFL team over a 23-year period. All players with combined thumb UCL

  11. Joint Assimilation of MODIS Land Surface Temperature and Airbone L-band Microwave Brightness Temperature into Land Surface Model in Irrigated Fields

    NASA Astrophysics Data System (ADS)

    Cao, Yongpan; Huang, Chunlin

    2017-04-01

    Both surface soil moisture and soil temperature are input variables for microwave transmission model which is as observation operator in a land surface data assimilation system. And the optimal estimation of soil moisture in irrigation fields is restricted by a lack of accurate irrigation information. The objective of this study was to evaluate the impact of the joint assimilation of passive microwave brightness temperature and land surface temperature data in a land surface model on soil moisture characterization under unknown (or known) irrigation conditions. A series of data assimilation experiments was conducted to evaluate the joint assimilation of MODIS land surface temperature and airborne Polarimetric L-band Multi-beam Radiometer (PLMR) brightness temperature into the Common Land Model (CoLM) using the Ensemble Kalman Smoother (EnKS). The Daman station, which is located at an irrigated maize farmland in the middle reaches of the Heihe River Basin, is selected in this study to investigate the performance of the proposed assimilation scheme. The following three tests were performed for unknown irrigation and known irrigation conditions: (1) assimilating brightness temperature observations only; (2) assimilating surface temperature observations only; and (3) assimilating both surface temperature and brightness temperature observations. The results show that the joint assimilation of surface temperature and brightness temperature results in the best characterization of soil moisture profiles under unknown irrigation conditions. The intake of irrigation information maintains good agreement with the true values, and tremendously reduce the RMSE exceed 50%. However, the single brightness temperature assimilation outperform the joint assimilation scheme under known irrigation conditions. Meanwhile, surface temperature assimilation resulted in improved estimation of soil moisture profiles.

  12. North American Mantle Heterogeneity from Joint Inversion of Body and Surface Waves

    NASA Astrophysics Data System (ADS)

    Lou, X.; Van der Lee, S.

    2011-12-01

    We have developed a Python/Matplotlib tool to measure teleseismic body wave arrival times. A graphic user interface is built to visualize seismograms and facilitate quality control. Seismic data from IRIS PASSCAL arrays and EarthScope's Transportable Array were processed with this tool to get teleseismic P and S relative delay times sampling both western and eastern North America. Distributions of delay times corrected for crustal structures show that the mantle east of the Rocky Mountains is at least as hetergeneous as that west of the Rocky Mountains. To better understand the heterogeneity within active and stable North America, we have simultaneously inverted relative S wave delay times and NA07's regional waveform fitting constraints for a new S velocity model. This joint inversion combines the complementary resolving powers of body and surface waves. The Rocky Mountains is a surface geological boundary separating active western and stable eastern US. But the actual boundary within the mantle does not necessary coincide with the location of the mountain front at the surface. At 150 km depth, high velocity Wyoming craton extends to west of the Rockies while low velocity anomalies in east Colorado and New Mexico extend to east of the Rockies. In western US, a dipping high velocity Juan de Fuca Slab extends continuously to the Transition Zone east of which are possibly older fragments of Farallon Plate. We do see a slab window beneath west central Oregon at about 150 km depth. Along the Snake River Plain, there are strong low velocities of up to 5% above 300 km depth. Low velocity of about 1% resides below 600 km depth, suggesting that the plume conduit beneath Yellowstone is not continuous.

  13. Slab geometry of the South American margin from joint inversion of body waves and surface waves

    NASA Astrophysics Data System (ADS)

    Porritt, R. W.; Ward, K. M.; Porter, R. C.; Portner, D. E.; Lynner, C.; Beck, S. L.; Zandt, G.

    2016-12-01

    The western margin of South America is a long subduction zone with a complex, highly three -dimensional geometry. The first order structure of the slab has previously been inferred from seismicity patterns and locations of volcanoes, but confirmation of the slab geometry by seismic imaging for the entire margin has been limited by either shallow, lithospheric scale models or broader, upper mantle images, often defined on a limited spatial footprint. Here, we present new teleseismic tomographic SV seismic models of the upper mantle from 10°S to 40°S along the South American subduction zone with resolution to a depth of 1000 km as inferred from checkerboard tests. In regions near the Peru Bolivia border (12°S to 18°S) and near central Chile and western Argentina (29.5°S to 33°S) we jointly invert the multi-band direct S and SKS relative delay times with Rayleigh wave phase velocities from ambient noise and teleseismic surface wave tomography. This self-consistent model provides information from the upper crust to below the mantle transition zone along the western margin in these two regions. This consistency allows tracing the slab from the South American coastline to the sub-transition zone upper mantle. From this model we image several features, but most notable is a significant eastward step near the southern edge of the margin (24°-30° S). West of this step, a large high shear velocity body is imaged in the base of and below the transition zone. We suggest this may be a stagnant slab, which is descending into the lower mantle now that it is no longer attached to the surface. This suggests a new component to the subduction history of western South America when an older slab lead the convergence before anchoring in the transition zone, breaking off from the surface, and being overtaken by the modern, actively subducting slab now located further east.

  14. Application of the surface azimuthal electrical resistivity survey method to determine patterns of regional joint orientation in glacial tills

    USGS Publications Warehouse

    Carlson, D.

    2010-01-01

    Joints within unconsolidated material such as glacial till can be primary avenues for the flow of electrical charge, water, and contaminants. To facilitate the siting and design of remediation programs, a need exists to map anisotropic distribution of such pathways within glacial tills by determining the azimuth of the dominant joint set. The azimuthal survey method uses standard resistivity equipment with a Wenner array rotated about a fixed center point at selected degree intervals that yields an apparent resistivity ellipse. From this ellipse, joint set orientation can be determined. Azimuthal surveys were conducted at 21 sites in a 500-km2 (193 mi2) area around Milwaukee, Wisconsin, and more specifically, at sites having more than 30 m (98 ft) of glacial till (to minimize the influence of underlying bedrock joints). The 26 azimuthal surveys revealed a systematic pattern to the trend of the dominant joint set within the tills, which is approximately parallel to ice flow direction during till deposition. The average orientation of the joint set parallel with the ice flow direction is N77??E and N37??E for the Oak Creek and Ozaukee tills, respectively. The mean difference between average direct observation of joint set orientations and average azimuthal resistivity results is 8??, which is one fifth of the difference of ice flow direction between the Ozaukee and Oak Creek tills. The results of this study suggest that the surface azimuthal electrical resistivity survey method used for local in situ studies can be a useful noninvasive method for delineating joint sets within shallow geologic material for regional studies. Copyright ?? 2010 The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  15. Factors associated with osteoarthritis of the hip and knee in Hong Kong Chinese: obesity, joint injury, and occupational activities.

    PubMed

    Lau, E C; Cooper, C; Lam, D; Chan, V N; Tsang, K K; Sham, A

    2000-11-01

    In 1998, a case-control study was conducted in Hong Kong on hospital patients with osteoarthritis of the hip (n = 138) and osteoarthritis of the knee (n = 658). Age- and sex-matched controls were recruited consecutively from general practice clinics in the same region. The following three risk factors were found to be associated with osteoarthritis of both the hip and the knee: first, a history of joint injury: for osteoarthritis of the hip, the odds ratio = 25.1 (95% confidence interval (CI): 3.5, 181) in men and 43.3 (95% CI: 11.7, 161) in women; for osteoarthritis of the knee, the odds ratio = 12.1 (95% CI: 3.4, 42.5) in men and 7.6 (95% CI: 3.8, 15.2) in women; second, climbing stairs frequently: for osteoarthritis of the hip, the odds ratio = 12.5 (95% CI: 1.5, 104.3) in men and 2.3 (95% CI: 0.6, 8.1) in women; for osteoarthritis of the knee, the odds ratio = 2.5 (95% CI: 1.0, 6.4) in men and 5.1 (95% CI: 2.5, 10.2) in women; third, lifting heavy weight frequently: for osteoarthritis of the hip, the odds ratio = 3.1 (95% CI: 0.7, 14.3) in men and 2.4 (95% CI: 1.1, 5.3) in women; for osteoarthritis of the knee, the odds ratio = 5.4 (95% CI: 2.4, 12.4) in men and 2.0 (95% CI: 1.2, 3.1) in women. In addition, subjects whose height and weight were in the highest quartile were at increased risk of osteoarthritis of the hip and knee, respectively (p < 0.05).

  16. The effect of playing surface on the incidence of ACL injuries in National Collegiate Athletic Association American Football.

    PubMed

    Dragoo, Jason L; Braun, Hillary J; Harris, Alex H S

    2013-06-01

    Artificial playing surfaces are widely used for American football practice and competition and anterior cruciate ligament (ACL) injuries are common. This study analyzed the National Collegiate Athletic Association (NCAA) Injury Surveillance System (ISS) men's football ACL injury database from 2004-2005 through 2008-2009 to determine the effect of playing surface on ACL injury in NCAA football athletes. This database was reviewed from the 2004-2005 through 2008-2009 seasons using the specific injury code, "Anterior cruciate ligament (ACL) complete tear." The injury rate was computed for competition and practice exposures. Ninety-five percent confidence intervals were calculated using assumptions of a Poisson distribution. Pair-wise, two-sample tests of equality of proportions with a continuity correction were used to estimate the associations of risk factors. There was an incidence rate of 1.73 ACL injuries per 10,000 athlete-exposures (A-Es) (95% CI 1.47-2.0) on artificial playing surfaces compared with a rate of 1.24 per 10,000 A-Es (1.05-1.45, p<0.001) on natural grass. The rate of ACL injury on artificial surfaces is 1.39 times higher than the injury rate on grass surfaces. Non-contact injuries occurred more frequently on artificial turf surfaces (44.29%) than on natural grass (36.12%). NCAA football players experience a greater number of ACL injuries when playing on artificial surfaces. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. The influence of hand positions on biomechanical injury risk factors at the wrist joint during the round-off skills in female gymnastics.

    PubMed

    Farana, Roman; Jandacka, Daniel; Uchytil, Jaroslav; Zahradnik, David; Irwin, Gareth

    2017-01-01

    The aim of this study was to examine the biomechanical injury risk factors at the wrist, including joint kinetics, kinematics and stiffness in the first and second contact limb for parallel and T-shape round-off (RO) techniques. Seven international-level female gymnasts performed 10 trials of the RO to back handspring with parallel and T-shape hand positions. Synchronised kinematic (3D motion analysis system; 247 Hz) and kinetic (two force plates; 1235 Hz) data were collected for each trial. A two-way repeated measure analysis of variance (ANOVA) assessed differences in the kinematic and kinetic parameters between the techniques for each contact limb. The main findings highlighted that in both the RO techniques, the second contact limb wrist joint is exposed to higher mechanical loads than the first contact limb demonstrated by increased axial compression force and loading rate. In the parallel technique, the second contact limb wrist joint is exposed to higher axial compression load. Differences between wrist joint kinetics highlight that the T-shape technique may potentially lead to reducing these bio-physical loads and consequently protect the second contact limb wrist joint from overload and biological failure. Highlighting the biomechanical risk factors facilitates the process of technique selection making more objective and safe.

  18. Periprosthetic Joint Infection in Hip Arthroplasty: Is There an Association Between Infection and Bearing Surface Type?

    PubMed

    Pitto, Rocco P; Sedel, Laurent

    2016-10-01

    Preliminary studies have raised the question of whether certain prosthetic biomaterials used in total hip arthroplasty (THA) bearings are associated with increased risk of periprosthetic joint infection (PJI). For example, some observational data suggest the risk of PJI is higher with metal-on-metal bearings. However, it is not known whether other bearings-including ceramic bearings or metal-on-polyethylene bearings-may be associated with a higher or lower risk of PJI. The objective of this study was to use a national arthroplasty registry to assess whether the choice of bearings-metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), ceramic-on-ceramic (CoC), or metal-on-metal (MoM)-is associated with differences in the risk of revision for deep infection, either (1) within 6 months or (2) over the entire period of observation, which spanned 15 years. Data from primary THAs were extracted from the New Zealand Joint Registry over a 15-year period. A total of 97,889 hips were available for analysis. Inclusion criterion was degenerative joint disease; exclusion criteria were previous surgery, trauma, and any other diagnosis (12,566 hips). We also excluded a small group of ceramic-on-metal THAs (429) with short followup. The median observation period of the selected group of hips (84,894) was 9 years (range, 1-15 years). The mean age of patients was 68 years (SD ± 11 years), and 52% were women. There were 54,409 (64%) MoP, 16,503 (19%) CoP, 9051 (11%) CoC, and 4931 (6%) MoM hip arthroplasties. Four hundred one hips were revised for deep infection. A multivariate assessment was carried out including the following risks factors available for analysis: age, sex, operating room type, use of body exhaust suits, THA fixation mode, and surgeon volume. Because of late introduction of data collection in the Registry, we were unable to include body mass index (BMI, recording started 2010) and medical comorbidities according to the American Society of Anesthesiologists

  19. Synovial Joints: from Development to Homeostasis

    PubMed Central

    Li, Tieshi; Tagliafierro, Lidia; Temple, Joseph D.; Willcockson, Helen H.; Ye, Ping; Esposito, Alessandra; Xu, Fuhua; Spagnoli, Anna

    2015-01-01

    Synovial joint morphogenesis occurs through the condensation of mesenchymal cells into a non-cartilaginous region known as interzone, and the specification of progenitor cells that commit to the articular fate. Although several signaling molecules are expressed by the interzone, the mechanism is poorly understood. For treatments of cartilage injuries, it is critical to discover the presence of joint progenitor cells in adult tissues and their expression gene pattern. Potential stem cells niches have been found in different joint regions, such as the surface zone of articular cartilage, synovium and groove of Ranvier. Inherited joint malformation as well as joint degenerating conditions are often associated with other skeletal defects, and may be seen as the failure of morphogenic factors to establish the correct microenvironment in cartilage and bone. Therefore, exploring how joints form can help us understand how cartilage and bone are damaged and to develop drugs to reactivate this developing mechanism. PMID:25431159

  20. Long-term management of severe ocular surface injury due to methamphetamine production accidents.

    PubMed

    Movahedan, Asadolah; Genereux, Brad M; Darvish-Zargar, Mahshad; Shah, Kevin J; Holland, Edward J

    2015-04-01

    The aim of this study was to report the clinical features and management of patients with ocular surface damage during methamphetamine production accidents. This is a retrospective noncomparative interventional case series of 5 patients with methamphetamine production-related ocular injuries referred to the Cincinnati Eye Institute between 1999 and 2014. Four of 5 cases were white young men with severe bilateral ocular injury and extremely poor vision. All except 1 eye (9 of 10) were diagnosed with total or near-total ocular surface failure. Limbal stem cell transplantation was performed in 8 of 10 eyes. Keratolimbal allograft was followed by penetrating keratoplasty in 7 of 10 eyes. Ocular surface stability was achieved in 7 of 10 eyes after keratolimabl allograft. Postoperative visual acuity was better than 20/200 in 4 of 10 of eyes. Keratolimbal graft rejection occurred in 3 of 10 eyes; the rate of rejection of penetrating keratoplasty was also 3 out of 10 eyes. Methamphetamine-related accidents can lead to severe bilateral ocular injuries. Although stem cell transplantation procedure success is guarded in most of these patients because of severe conjunctival inflammation and accompanying ocular comorbidities, as well as personality issues, compliant patients can achieve good visual function with ocular surface transplantation and subsequent keratoplasty.

  1. Surface electromyographic assessment of patients with long lasting temporomandibular joint disorder pain.

    PubMed

    Tartaglia, Gianluca M; Lodetti, Gianluigi; Paiva, Guiovaldo; De Felicio, Claudia Maria; Sforza, Chiarella

    2011-08-01

    The normalized electromyographic characteristics of masticatory muscles in patients with temporomandibular joint disorders (TMD) and healthy controls were compared. Thirty TMD patients (15 men, 15 women, mean age 23 years) with long lasting pain (more than 6 months), and 20 control subjects matched for sex and age were examined. All patients had arthrogenous TMD according to the Research Diagnostic Criteria for TMD (RDC/TMD). Surface electromyography of masseter and temporal muscles was performed during maximum teeth clenching either on cotton rolls or in intercuspal position. Standardized EMG indices and the median power frequency were obtained, and compared between the two groups and sexes using ANOVAs. During clenching, the TMD patients had larger asymmetry in their temporalis muscles, larger temporalis activity relative to masseter, and reduced mean power frequencies than the control subjects (p<0.05, ANOVA). In both groups, the mean power frequencies of the temporalis muscles were larger than those of the masseter muscles (p<0.001). No sex related differences, and no sex × group interactions were found. In conclusion, young adult patients with long lasting TMD have an increased and more asymmetric standardized activity of their temporalis anterior muscle, and reduced mean power frequencies, relative to healthy controls.

  2. Lithospheric structure beneath northern Mississippi embayment from joint inversion of surface wave dispersion and receiver functions

    NASA Astrophysics Data System (ADS)

    Su, Han

    The northern Mississippi Embayment is characterized by relatively high seismicity at the New Madrid Seismic Zone. Although many studies have focused on specific earthquakes or on the structure at specific locations, the mechanism of the earthquake process has remained an enigma. As part of the Northern Embayment Lithosphere Experiment, we focus on high resolution surface-wave tomography of Love and Rayleigh, phase and group velocities for a study region bounded by 34-40 N latitude and 85-94 W longitude for periods from 2 to 50 seconds by cross-correlating ambient noise from BH channels of the Transportable Array of EarthScope. To test the usefulness of the dispersion, we perform a joint inversion of dispersion and teleseismic P-wave receiver functions for stations in the region. At a few locations, we are able to test the resulting models by comparing predicted to observed broadband recordings of local earthquakes. At these few locations, we find good agreement and also evidence that the Moho is a gradient rather than a sharp discontinuity.

  3. Joint segmentation of 3D femoral lumen and outer wall surfaces from MR images.

    PubMed

    Ukwatta, Eranga; Yuan, Jing; Qiu, Wu; Rajchl, Martin; Chiu, Bernard; Shavakh, Shadi; Xu, Jianrong; Fenster, Aaron

    2013-01-01

    We propose a novel algorithm to jointly delineate the femoral artery lumen and outer wall surfaces from 3D black-blood MR images, while enforcing the spatial consistency of the reoriented MR slices along the medial axis of the femoral artery. We demonstrate that the resulting optimization problem of the proposed segmentation can be solved globally and exactly by means of convex relaxation, for which we introduce a novel coupled continuous max-flow (CCOMF) model based on an Ishikawa-type flow configuration and show its duality to the studied convex relaxed optimization problem. Using the proposed CCMF model, the exactness and globalness of its dual convex relaxation problem is proven. Experiment results demonstrate that the proposed method yielded high accuracy (i.e. Dice similarity coefficient > 85%) for both the lumen and outer wall and high reproducibility (intra-class correlation coefficient of 0.95) for generating vessel wall area. The proposed method outperformed the previous method, in terms of computation time, by a factor of pproximately 20.

  4. Joint spatiotemporal variability of global sea surface temperatures and global Palmer drought severity index values

    USGS Publications Warehouse

    Apipattanavis, S.; McCabe, G.J.; Rajagopalan, B.; Gangopadhyay, S.

    2009-01-01

    Dominant modes of individual and joint variability in global sea surface temperatures (SST) and global Palmer drought severity index (PDSI) values for the twentieth century are identified through a multivariate frequency domain singular value decomposition. This analysis indicates that a secular trend and variability related to the El Niño–Southern Oscillation (ENSO) are the dominant modes of variance shared among the global datasets. For the SST data the secular trend corresponds to a positive trend in Indian Ocean and South Atlantic SSTs, and a negative trend in North Pacific and North Atlantic SSTs. The ENSO reconstruction shows a strong signal in the tropical Pacific, North Pacific, and Indian Ocean regions. For the PDSI data, the secular trend reconstruction shows high amplitudes over central Africa including the Sahel, whereas the regions with strong ENSO amplitudes in PDSI are the southwestern and northwestern United States, South Africa, northeastern Brazil, central Africa, the Indian subcontinent, and Australia. An additional significant frequency, multidecadal variability, is identified for the Northern Hemisphere. This multidecadal frequency appears to be related to the Atlantic multidecadal oscillation (AMO). The multidecadal frequency is statistically significant in the Northern Hemisphere SST data, but is statistically nonsignificant in the PDSI data.

  5. Accelerated and increased joint damage in young mice with global inactivation of mitogen-inducible gene 6 after ligament and meniscus injury

    PubMed Central

    2014-01-01

    Introduction Ligament and meniscal damage can cause joint disease. Arthritic joints contain increased amounts of epidermal growth factor receptor (EGFR) protein, and polymorphisms in EGFR are associated with arthritis risk. The role of endogenous EGFR regulation during joint disease due to ligament and meniscal trauma is unknown. Mitogen-inducible gene 6 (MIG-6) can reduce EGFR phosphorylation and downstream signaling. We examined the effect of EGFR modulation by MIG-6 on joint disease development after ligament and meniscus injury. Methods Knee ligament transection and meniscus removal were performed surgically on mice homozygous for a global inactivating mutation in MIG-6 (Mig-6−/−) and in wild-type (WT) animals. Results Two weeks after surgery, Mig-6−/−mice had bone erosion as well as greater fibrous tissue area and serum RANKL concentration than WT mice. Four weeks after surgery, Mig-6−/−mice had less cartilage and increased cell proliferation relative to contralateral control and WT knees. Increased apoptotic cells and growth outside the articulating region occurred in Mig-6−/−mice. Tibia trabecular bone mineral density (BMD) and the number of trabeculae were lower in surgically treated knees relative to the respective control knees for both groups. BMD, as well as trabecular thickness and number, were lower in surgically treated knees from Mig-6−/−mice relative to WT surgically treated knees. Phosphorylated EGFR staining in surgically treated knees decreased for WT mice and increased for Mig-6−/−mice. Fewer inflammatory cells were present in the knees of WT mice. Conclusion Mig-6−/−mice have rapid and increased joint damage after ligament and meniscal trauma. Mig-6 modification could lessen degenerative disease development after this type of injury. PMID:24670222

  6. Kinematics of the proximal interphalangeal joint of the finger after surface replacement.

    PubMed

    Uchiyama, S; Cooney, W P; Linscheid, R L; Niebur, G; An, K N

    2000-03-01

    Nine fresh-frozen normal human cadaveric long fingers were used to compare the kinematics of the proximal interphalangeal joint (PIP) before and after a resurfacing metal-polyethylene prosthetic replacement (Avanta prosthesis, San Diego, CA) using the magnetic Isotrak system (Polhemus Navigational Systems, Colchester, VT). The kinematics of the PIP joint after replacement were similar to that of the normal joint. The maximum angular displacement was 5 degrees for lateral deviation and 9 degrees for rotation during the passive flexion and extension motion. The center of rotation after implant insertion was nearly identical to the center of rotation of the normal joint. This anatomically designed PIP prosthesis has potential to restore normal motion to the finger PIP joint while resisting physiologic out-of-plane forces such as pinch and grasp. Copyright 2000 by the American Society for Surgery of the Hand.

  7. The potential for brain injury on selected surfaces used by cheerleaders.

    PubMed

    Shields, Brenda J; Smith, Gary A

    2009-01-01

    Although playground surfaces have been investigated for fall impact attenuation, the surfaces that cheerleaders use have received little attention. To determine (1) the critical height for selected surfaces used by cheerleaders at or below which a serious head impact injury from a fall is unlikely to occur, (2) the critical heights for non-impact-absorbing surfaces for comparison purposes, and (3) the effect of soil moisture and grass height on g(max) (which is defined as the multiple of g [acceleration due to gravity at the earth's surface at sea level: ie, 32.2 feet x s(-1) x s(-1)] that represents the maximum deceleration experienced during an impact) and the Head Injury Criterion (HIC) at the critical height for a dry grass surface. Observational study. A local cheerleading gym, indoor locations within the authors' institution, and various outdoor locations. g(max), HIC, and critical height. Critical heights for the surfaces tested ranged from 0.5 ft (0.15 m) for concrete and vinyl tile installed over concrete to more than 11 ft (3.35 m) for a spring floor. Increases in grass height and soil moisture resulted in an increase in the critical height for grass surfaces. Only spring floors and 4-in (0.10-m)-thick landing mats placed on traditional foam floors had critical heights greater than 10.5 ft (3.20 m), thus providing enough impact-absorbing capacity for performance of 2-level stunts. The potential for serious head impact injuries can be minimized by increasing the shock-absorbing capacity of the surface, decreasing the height from which the person falls, or both. Cheerleaders and cheerleading coaches should use the critical heights reported in this study to compare the relative impact-absorbing capacities of the various surfaces tested, with critical height as an indicator of the impact-absorption capacity of the surface. The findings of this study can be used to select the most appropriate surface for the type of maneuver to be performed, based on the

  8. The Potential for Brain Injury on Selected Surfaces Used by Cheerleaders

    PubMed Central

    Shields, Brenda J.; Smith, Gary A.

    2009-01-01

    Abstract Context: Although playground surfaces have been investigated for fall impact attenuation, the surfaces that cheerleaders use have received little attention. Objective: To determine (1) the critical height for selected surfaces used by cheerleaders at or below which a serious head impact injury from a fall is unlikely to occur, (2) the critical heights for non–impact-absorbing surfaces for comparison purposes, and (3) the effect of soil moisture and grass height on gmax (which is defined as the multiple of g [acceleration due to gravity at the earth's surface at sea level: ie, 32.2 feet·s−1·s−1] that represents the maximum deceleration experienced during an impact) and the Head Injury Criterion (HIC) at the critical height for a dry grass surface. Design: Observational study. Settings: A local cheerleading gym, indoor locations within the authors' institution, and various outdoor locations. Main Outcome Measure(s): gmax, HIC, and critical height. Results: Critical heights for the surfaces tested ranged from 0.5 ft (0.15 m) for concrete and vinyl tile installed over concrete to more than 11 ft (3.35 m) for a spring floor. Increases in grass height and soil moisture resulted in an increase in the critical height for grass surfaces. Only spring floors and 4-in (0.10-m)–thick landing mats placed on traditional foam floors had critical heights greater than 10.5 ft (3.20 m), thus providing enough impact-absorbing capacity for performance of 2-level stunts. Conclusions: The potential for serious head impact injuries can be minimized by increasing the shock-absorbing capacity of the surface, decreasing the height from which the person falls, or both. Cheerleaders and cheerleading coaches should use the critical heights reported in this study to compare the relative impact-absorbing capacities of the various surfaces tested, with critical height as an indicator of the impact-absorption capacity of the surface. The findings of this study can be used to

  9. Rugby injuries.

    PubMed

    McIntosh, Andrew S

    2005-01-01

    The purpose of this chapter is to review critically the existing studies on the epidemiology of pediatric rugby injuries and discuss suggestions for injury prevention and further research. Data were sourced from the sports medicine and science literature mainly since 1990, and from a prospective injury surveillance project in rugby undertaken by the University of New South Wales (UNSW) in Sydney during 2002. Literature searches were performed using Medline and SportsDiscus. Reported injury rates were between 7 and 18 injuries per 1,000 hours played, with the rate of injuries resulting in loss of playing or training time measured at 6.5-10.6 per 1,000 hours played. Injury rates increased with age and level of qualification. Head injury and concussion accounted for 10-40% of all injuries. In the UNSW study, concussion accounted for 25% of injuries resulting in loss of playing or training time in the under 13 year age group. Upper and lower extremity injuries were equally apportioned, with musculoskeletal injuries being the main type of injury. Fractures were observed in the upper extremity and ankle, and joint/ligament injuries affected the shoulder, knee and ankle. The tackle was associated with around 50% of all injuries. The scrum produced fewer injuries, but is historically associated with spinal cord injury. Rugby is a contact sport with injury risks related to physical contact, primarily in the tackle. Most injuries affect the musculoskeletal system, with the exception of concussion. Spinal cord injury is rare, but catastrophic. Research is required to understand better injury risks and to reduce the incidence of shoulder, knee and ankle joint injuries, concussion and spinal injury.

  10. Joint Assimilation of MODIS Surface Temperature and Airbone L-band Microwave Brightness Temperature into Land Surface Model in Irrigated Fields

    NASA Astrophysics Data System (ADS)

    Cao, Y.; Huang, C.; Wang, W.

    2016-12-01

    Both surface soil moisture and soil temperature are input variables for microwave transmission model which is as observation operator in a land surface data assimilation system. And the optimal estimation of soil moisture in irrigation fields is restricted by a lack of accurate irrigation information. The objective of this study was to evaluate the impact of the joint assimilation of passive microwave brightness temperature and land surface temperature data in a land surface model on soil moisture characterization under unknown (or known) irrigation conditions. A series of data assimilation experiments was conducted to evaluate the joint assimilation of MODIS land surface temperature and airborne Polarimetric L-band Multi-beam Radiometer (PLMR) brightness temperature into the Common Land Model (CoLM) using the Ensemble Kalman Smoother (EnKS). The Daman station, which is located at an irrigated maize farmland in the middle reaches of the Heihe River Basin, is selected in this study to investigate the performance of the proposed assimilation scheme. The following three tests were performed for unknown irrigation and known irrigation conditions: (1) assimilating brightness temperature observations only; (2) assimilating surface temperature observations only; and (3) assimilating both surface temperature and brightness temperature observations. The results show that the joint assimilation of surface temperature and brightness temperature results in the best characterization of soil moisture profiles under unknown irrigation conditions. The joint assimilation RMSE decreases from 0.183 m3/m3 to 0.089 m3/m3 in the 4cm layer, while only brightness temperature assimilation decreases to 0.113 m3/m3. The intake of irrigation information maintains good agreement with the true values, and tremendously reduce the RMSE from 0.183 m3/m3 to 0.065 m3/m3, exceed 50%. However, the single brightness temperature assimilation outperform the joint assimilation scheme under known

  11. Joint Test Protocol for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2005-01-01

    Headquarters National Aeronautics and Space Administration (NASA) chartered the Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the AP2 Office are to: (1) Reduce or eliminate the use of hazardous materials (HazMats) or hazardous processes at manufacturing, remanufacturing, and sustainment locations. (2) A void duplication of effort in actions required to reduce or eliminate HazMats through joint center cooperation and technology sharing. This project will identify, evaluate and approve alternative surface preparation technologies for use at NASA and Air Force Space Command (AFSPC) installations. Materials and processes will be evaluated with the goal of selecting those processes that will improve corrosion protection at critical systems, facilitate easier maintenance activity, extend maintenance cycles, eliminate flight hardware contamination and reduce the amount of hazardous waste generated. This Joint Test Protocol (JTP) contains the critical requirements and tests necessary to qualify alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel Applications. These tests were derived from engineering, performance, and operational impact (supportability) requirements defined by a consensus of NASA and Air Force Space Command (AFSPC) participants. The Field Test Plan (FTP), entitled Joint Test Protocol for Validation of Alternative Low Emission Surface Preparation/Depainting Technologies for Structural Steel, prepared by ITB, defines the field evaluation and testing requirements for validating alternative surface preparation/depainting technologies and supplements the JTP.

  12. Joint Test Report for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2007-01-01

    Headquarters National Aeronautics and Space Administration (NASA) chartered the NASA Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the AP2 Office are to: (1) Reduce or eliminate the use of hazardous materials or hazardous processes at manufacturing, remanufacturing, and sustainment locations. (2) Avoid duplication of effort in actions required to reduce or eliminate hazardous materials through joint center cooperation and technology sharing. The objective of this project was to qualify candidate alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel applications at NASA facilities. This project compares the surface preparation/depainting performance of the proposed alternatives to existing surface preparation/depainting systems or standards. This Joint Test Report (JTR) contains the results of testing as per the outlines of the Joint Test Protocol (JTP), Joint Test Protocol for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel, and the Field Test Plan (FTP), Field Evaluations Test Plan for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel, for critical requirements and tests necessary to qualify alternatives for coating removal systems. These tests were derived from engineering, performance, and operational impact (supportability) requirements defined by a consensus of government and industry participants. This JTR documents the results of the testing as well as any test modifications made during the execution of the project. This JTR is made available as a reference for future pollution prevention endeavors by other NASA Centers, the Department of Defense and commercial users to minimize duplication of effort. The current coating removal processes

  13. Influence of nickel-phosphorus surface roughness on wettability and pores formation in solder joints for high power electronic applications

    NASA Astrophysics Data System (ADS)

    Vivet, L.; Joudrier, A.-L.; Tan, K.-L.; Morelle, J.-M.; Etcheberry, A.; Chalumeau, L.

    2013-12-01

    Electroless nickel-high-phosphorus Ni-P plating is used as substrate coating in the electronic component technology. The ability to minimize pores formation in solder joints and the wettability of the Ni-P layer remain points of investigation. The qualities and the control of the physical and chemical properties of the deposits are essential for the reliability of the products. In this contribution it has been measured how a controlled change of one property of the Ni-P surface, its average roughness, changes the wettability of this surface before soldering completion, at ambient temperature and under ambient air, and how it contribute to change the amount and size of pores inside solder joints, after soldering completion. Before all, observations of the Ni-P surfaces using scanning electron microscopy have been achieved. Then the wettability has been measured through the determination of both the disperse and the polar fractions of the substrate surface tension, based on the measurements of the wetting angle for droplets of four different liquids, under ambient air and at room temperature (classical sessile drop technique). Finally the X-ray micro-radiography measurements of both the area fraction of pores and the size of the largest pore inside the solder joint of dice laser soldered on the studied substrate, using high melting temperature solder (300 °C, PbSnAg) have been achieved. This study clearly demonstrates that both the ability to minimize pores formation in solder joints and the wettability under ambient conditions of the Ni-P substrate decrease and become more variable when its average roughness increases. These effects can be explained considering the Cassie-Baxter model for rough surface wetting behaviour, completed by the model of heterogeneous nucleation and growth for gas bubbles inside a liquid.

  14. Observation of the Degradation Characteristics and Scale of Unevenness on Three-dimensional Artificial Rock Joint Surfaces Subjected to Shear

    NASA Astrophysics Data System (ADS)

    Hong, Eun-Soo; Kwon, Tae-Hyuk; Song, Ki-Il; Cho, Gye-Chun

    2016-01-01

    The present study explores the degradation characteristics and scale of unevenness (small-scale roughness) on sheared rock joint surfaces at a low-stress regime. While the degradation characteristics of unevenness and the normal stress are mutually interrelated, an understanding of the degradation patterns of the three-dimensional roughness of rock joints is one of the important components needed to identify asperity failure characteristics and to quantify the role of damaged unevenness in establishing a shear strength model. A series of direct shear tests was performed on three-dimensional artificial rock joint surfaces at different normal stress levels. After shearing, the spatial distributions and statistical parameters of degraded roughness were analysed for the different normal stress levels. The length and area of the degraded zones showed bell-shaped distributions in a logarithmic scale, and the dominant scale (or the most frequently occurring scale) of the damaged asperities (i.e., unevenness) ranged from approximately, 0.5 to 5.0 mm in length and 0.1-10 mm2 in area. This scale of the damaged unevenness was consistent regardless of the level of normal stress. It was also found that the relative area of damaged unevenness on a given joint area, and thus the contribution of the mechanical asperity failure component to shear strength increased as normal stress increased.

  15. Characterization of surface electromyography patterns of healthy and incomplete spinal cord injury subjects interacting with an upper-extremity exoskeleton.

    PubMed

    McDonald, Craig G; Dennis, Troy A; O'Malley, Marcia K

    2017-07-01

    Rehabilitation exoskeletons may make use of myoelectric control to restore in patients with significant motor impairment following a spinal cord injury (SCI) a sense of volitional control over their limb - a crucial component for recovery of movement. Little investigation has been done into the feasibility of using surface electromyography (sEMG) as an exoskeleton control interface for SCI patients, whose impairment manifests in a highly variable way across the patient population. We have demonstrated that by using only a small subset of features extracted from eight bipolar electrodes recording on the upper arm and forearm muscles, we can achieve high predictive accuracy for the intended direction of motion. Five healthy subjects and two SCI subjects performed voluntary isometric contractions while wearing an exoskeleton for the wrist and elbow joints, generating six distinct single and multi-DoF motions in a total of sixteen possible directions. Using linear discriminant analysis, classification performance was then evaluated using randomly selected holdout test data from the same recording session. Commonalities across subjects, both healthy and SCI, were analyzed at the levels of selected features and the values of commonly selected features. Future work will be to investigate group-specific classification of SCI subjects' intended movements for use in the real-time control of a rehabilitation exoskeleton.

  16. Ceramic joints

    DOEpatents

    Miller, Bradley J.; Patten, Jr., Donald O.

    1991-01-01

    Butt joints between materials having different coefficients of thermal expansion are prepared having a reduced probability of failure of stress facture. This is accomplished by narrowing/tapering the material having the lower coefficient of thermal expansion in a direction away from the joint interface and not joining the narrow-tapered surface to the material having the higher coefficient of thermal expansion.

  17. Exploring caregiver behavior and knowledge about unsafe sleep surfaces in infant injury death cases.

    PubMed

    Chu, Tracy; Hackett, Martine; Kaur, Navpreet

    2015-06-01

    In the United States, infant deaths due to sleep-related injuries have quadrupled over the past two decades. One of the major risk factors is the placement of an infant to sleep on a surface other than a crib or bassinet. This study examines contextual circumstances and knowledge and behaviors that may contribute to the placement of infants on an unsafe sleep surface in infant injury death cases. This study employed a retrospective review of 255 sleep-related injury death cases in New York City from 2004 to 2010 where an infant was found sleeping on an unsafe sleep surface. Mixed-methods analyses, employing both quantitative analysis of vital statistics data and risk variables extracted from the medical examiner files and qualitative analysis of the narrative content of the files, were conducted. In 48% of cases, a crib or bassinet was identified in the home. Quantitative analysis revealed no significant differences in demographic or risk factor characteristics between infants who had a crib or bassinet and those who did not. Qualitative analysis highlighted factors in caregivers' decision making related to situational convenience, preference, and misconceptions concerning safe infant sleep. The health belief model (HBM), specifically the constructs of perceived susceptibility, severity, benefits, and barriers, was used as a lens to understand factors associated with caregiver behavior. This study provides evidence that infants are at risk of sleep-related injury death even when a crib or bassinet is present. Understanding the factors that may influence safe sleep behaviors can help produce more appropriate interventions. © 2014 Society for Public Health Education.

  18. 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.

  19. Severe injury of bilateral elbow joints with unilateral terrible triad of the elbow and unilateral suspected terrible triad of the elbow complicated with olecranon fracture: one case report

    PubMed Central

    Zha, Guoqing; Niu, Xiaofeng; Yu, Weiguang; Xiao, Liangbao

    2015-01-01

    Terrible triad of the elbow is characterized as posterior dislocation of the elbow joint accompanied by the fractures of the radial head and coronoid process of the ulna, which is rarely seen in clinical practice, especially because the mild fracture is barely detected by imaging method In this study, we reported one case of serious complex bilateral elbow injury, presenting with unilateral typical terrible triad of the elbow and suspected terrible triad of the elbow complicated with olecranon fracture on the other side. Clinical experience was obtained during the diagnosis and treatment procedures. PMID:26550399

  20. Micro-optical rotary joint for multichannel communication via a rotating surface

    NASA Astrophysics Data System (ADS)

    Stark, Markus; Rank, Matthias; Schmidt, Michael; Popp, Gregor; Poisel, Hans

    2005-04-01

    Data transmission between rotating and stationary systems, e.g. required for radar antennas or for undersea cable installation ships can be realized with so called rotary joints. For the transmission of several high bit rate optical data channels a micro optical rotary joint is now available which guarantees a dead reliable, low loss transmission for up to 21 parallel single mode channels. The free space transmission in the rotary joint implicates a highly precise collimation of the parallel channels. For this purpose compact two dimensional fiber collimator arrays based on micro lens arrays have been developed. These arrays and the complete opto-mechanical system are designed with the help of tolerance analysis using Monte Carlo simulations. Besides these results also some more information on the behavior and the characteristics of the micro optical rotary joint under real conditions which demonstrate the excellent characteristics of this novel system will be given.

  1. The influence of an artificial playing surface on injury risk and perceptions of muscle soreness in elite Rugby Union.

    PubMed

    Williams, S; Trewartha, G; Kemp, S P T; Michell, R; Stokes, K A

    2016-01-01

    This prospective cohort study investigated the influence of an artificial playing surface on injury risk and perceptions of muscle soreness in elite English Premiership Rugby Union players. Time loss (from 39.5 matches) and abrasion (from 27 matches) injury risk was compared between matches played on artificial turf and natural grass. Muscle soreness was reported over the 4 days following one match played on each surface by 95 visiting players (i.e., normally play on natural grass surfaces). There was a likely trivial difference in the overall injury burden relating to time-loss injuries between playing surfaces [rate ratio = 1.01, 90% confidence interval (CI): 0.73-1.38]. Abrasions were substantially more common on artificial turf (rate ratio = 7.92, 90% CI: 4.39-14.28), although the majority of these were minor and only two resulted in any reported time loss. Muscle soreness was consistently higher over the 4 days following a match on artificial turf in comparison with natural grass, although the magnitude of this effect was small (effect sizes ranging from 0.26 to 0.40). These results suggest that overall injury risk is similar for the two playing surfaces, but further surveillance is required before inferences regarding specific injury diagnoses and smaller differences in overall injury risk can be made.

  2. Emerging options for treatment of articular cartilage injury in the athlete.

    PubMed

    Mithoefer, Kai; McAdams, Timothy R; Scopp, Jason M; Mandelbaum, Bert R

    2009-01-01

    Articular cartilage injury is observed with increasing frequency in both elite and amateur athletes and results from the significant joint stress associated particularly with high-impact sports. The lack of spontaneous healing of these joint surface defects leads to progressive joint pain and mechanical symptoms with resulting functional impairment and limitation of athletic participation. Left untreated, articular cartilage defects can lead to chronic joint degeneration and athletic disability. Articular cartilage repair in athletes requires effective and durable joint surface restoration that can withstand the significant joint stresses generated during athletic activity. Several techniques for articular cartilage repair have been developed recently, which can successfully restore articular cartilage surfaces and allow for return to high-impact athletics after articular cartilage injury. Besides these existing techniques, new promising scientific concepts and techniques are emerging that incorporate modern tissue engineering technologies and promise further improvement for the treatment of these challenging injuries in the demanding athletic population.

  3. An evaluation of the blind lap joint for the surface mount attachment of chip components

    SciTech Connect

    Vianco, P T; Dal Porto, J F

    1992-01-01

    Blind lap solder joints were used to attach leadless ceramic chip resistors to polyimidequartz circuit boards. Hand soldering and vapor phase reflow techniques were evaluated. The solder was 62Sn-36Pb-2Ag (wt.%). The integrity of the solder joints was assessed by microstructural examination and room temperature shear tests. These analyses were performed on as-fabricated circuit boards as well as an those samples exposed to thermal cycling (308 cycles; {minus}55{degree} to 125{degree}C; 6{degree}C/min ramps; 120 min hold periods;) or thermal shock (100 cycles, {minus}55{degree}C to 125{degree}C; liquid-to-liquid transfer; 10 min hold periods). In all cases, microscopy revealed no cracks within the solder joints. The shear strengths of the joints were 13.4 lb (59 N), as-fabricated; 10.5 lb (47 N), 308 thermal cycles; and 14.0 lb (62 N), 100 thermal shock cycles. All values were well within acceptability limits for the particular application. Measurements of the intermetallic compound thicknesses at the copper land/solder interface indicated that the additional heating cycle of the hand soldering step decreased the layer thickness as compared to non-hand soldered joints. The successful implementation of the blind lap joint can provide increased device densities on circuit boards by reducing bonding pad extension beyond the ceramic chip foot print.

  4. Jointly deriving NMR surface relaxivity and pore size distributions by NMR relaxation experiments on partially desaturated rocks

    NASA Astrophysics Data System (ADS)

    Mohnke, O.; Hughes, B.

    2014-06-01

    Nuclear magnetic resonance (NMR) relaxometry is a geophysical method widely used in borehole and laboratory applications to nondestructively infer transport and storage properties of rocks and soils as it is directly sensitive to the water/oil content and pore sizes. However, for inferring pore sizes, NMR relaxometry data need to be calibrated with respect to a surface interaction parameter, surface relaxivity, which depends on the type and mineral constituents of the investigated rock. This study introduces an inexpensive and quick alternative to the classical calibration methods, e.g., mercury injection, pulsed field gradient (PFG) NMR, or grain size analysis, which allows for jointly estimating NMR surface relaxivity and pore size distributions using NMR relaxometry data from partially desaturated rocks. Hereby, NMR relaxation experiments are performed on the fully saturated sample and on a sample partially drained at a known differential pressure. Based on these data, the (capillary) pore radius distribution and surface relaxivity are derived by joint optimization of the Brownstein-Tarr and the Young-Laplace equation assuming parallel capillaries. Moreover, the resulting pore size distributions can be used to predict water retention curves. This inverse modeling approach—tested and validated using NMR relaxometry data measured on synthetic porous borosilicate samples with known petrophysical properties (i.e., permeability, porosity, inner surfaces, pore size distributions)—yields consistent and reproducible estimates of surface relaxivity and pore radii distributions. Also, subsequently calculated water retention curves generally correlate well with measured water retention curves.

  5. Study of surface bonding imperfection effects on equivalent identified dynamic Young's and shear moduli using a modal based joint identification method

    NASA Astrophysics Data System (ADS)

    Meshki, M. M.; Nobari, A. S.; Nikbin, K.

    2015-02-01

    In this paper the effects of defects on the equivalent identified dynamic Young's and shear moduli of flexible structural adhesive joints have been investigated. Adhesive joints were subjected to initial surface bonding imperfection, in order to simulate the defects. Several debond patterns have been applied artificially on single-lap joint specimens and joint identification process has been performed for both bending and shear modes to see how surface bonding imperfection can affect equivalent identified dynamic Young's and shear moduli of the adhesive. Using a direct modal based method to identify mechanical characteristics of joints has been shown that degradation of the equivalent moduli of debonded joint is correlated to both frequency and mode shapes. The results reveal that debonding is easily detectable in bending modes whereas degradation in shear modes is also correlated to debonding orientation and mode shapes. Three identical specimens have been tested for each case to prove the consistency of the results.

  6. Wear of cross-linked polyethylene against itself: a material suitable for surface replacement of the finger joint.

    PubMed

    Sibly, T F; Unsworth, A

    1991-05-01

    Cross-linking of polyethylene (XLPE) has dramatically improved its properties in industrial applications, and it may also have some application in the field of human joint replacement. Additionally it has the advantage of permitting a lower molecular weight base material to be used, so that components may be injection moulded rather than machined. This study therefore investigates the wear resistance of medical grade cross-linked polyethylene (XLPE), cross-linked by a silane-grafting process, with a molecular weight between cross links of 5430 g mol(-1). This first report investigates the wear resistance of XLPE against itself, because for certain joints, such as the metacarpo-phalangeal joint, the material may have a high enough wear resistance to allow both bearing surfaces to be made from it. Tests were carried out both on a reciprocating pin and plate machine with pins loaded at 10 and 40 N and also on a new finger joint simulator, which simulates the loads applied to and the movements of, the metacarpo-phalangeal joint. An average wear rate of 1.8 x 10(-6) mm3 N-1 m-1 was found (range 0.9-2.75 x 10(-6) mm3 N-1 m-1). This is about six times greater than the wear rate of non-cross-linked ultra high molecular weight polyethylene (UHMWPE) against stainless steel, but for applications with low loading, such as the metacarpo-phalangeal joint, this material is shown to have adequate wear resistance. The coefficient of friction was 0.1, which is similar to that of UHMWPE on stainless steel.

  7. Hip and knee net joint moments that correlate with success in lateral load transfers over a low friction surface.

    PubMed

    Catena, Robert D; Xu, Xu

    2016-12-01

    We previously described two different preferred strategies used to perform a lateral load transfer. The wide stance strategy was not used successfully on a low-friction surface, while the narrow stance strategy was successful. Here, we retrospectively examined lower extremity net joint moments between successful and unsuccessful strategies to determine if there is a kinetic benefit consideration that may go into choosing the preferred strategy. Success vs. failure over a novel slippery surface was used to dichotomise 35 healthy working-age individuals into the two groups (successful and unsuccessful). Participants performed lateral load transfers over three sequential surface conditions: high friction, novel low friction and practised low friction. The unsuccessful strategy required larger start torques, but lower dynamic moments during transfer compared to the successful strategy. These results indicate that the periodically unsuccessful strategy may be preferred because it requires less muscle recruitment and lower stresses on lower extremity soft tissues. Practitioner Summary: The reason for this paper is to retrospectively examine the joint moment in two different load transfer strategies that are used in a lateral load transfer. We found that periodically unsuccessful strategies that we previously reported may be a beneficial toward reduced lower extremity joint stresses.

  8. How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

    NASA Astrophysics Data System (ADS)

    Suhir, E.; Yi, S.; Ghaffarian, R.

    2017-01-01

    It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.

  9. How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

    NASA Astrophysics Data System (ADS)

    Suhir, E.; Yi, S.; Ghaffarian, R.

    2017-03-01

    It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.

  10. Quantification of functional brace forces for posterior cruciate ligament injuries on the knee joint: an in vivo investigation.

    PubMed

    LaPrade, Robert F; Smith, Sean D; Wilson, Katharine J; Wijdicks, Coen A

    2015-10-01

    Counteracting posterior translation of the tibia with an anterior force on the posterior proximal tibia has been demonstrated clinically to improve posterior knee laxity following posterior cruciate ligament (PCL) injury. This study quantified forces applied to the posterior proximal tibia by two knee braces designed for treatment of PCL injuries. The forces applied by two knee braces to the posterior proximal tibia and in vivo three-dimensional knee kinematics of six adult, male, healthy volunteer subjects (mean ± standard deviation: height, 182.5 ± 5.2 cm; body mass, 83.2 ± 9.3 kg; body mass index, 24.9 ± 1.5 kg/m(2); age, 25.8 ± 2.9 years) were measured using a custom pressure mapping technique and traditional surface marker motion capture techniques, while subjects performed three functional activities. The activities included seated unloaded knee flexion, squatting, and stair descent in a new generation dynamic force (DF) PCL brace and a static force (SF) PCL brace. During unloaded flexion at the lowest force level setting, the force applied by the DF brace increased as a function of flexion angle (slope = 0.7 N/°; p < 0.001) compared to the SF brace effect. Force applied by the SF brace did not significantly change as a function of flexion angle (slope = 0.0 N/°; n.s.). By 45° of flexion, the average force applied by the DF brace (48.1 N) was significantly larger (p < 0.001) than the average force applied by the SF brace (25.0 N). The difference in force continued to increase as flexion angle increased. During stair descent, average force (mean ± standard deviation) at toe off was significantly higher (p = 0.013) for the DF brace (78.7 ± 21.6 N) than the SF brace (37.3 ± 7.2 N). Similar trends were observed for squatting and for the higher force level settings. The DF brace applied forces to the posterior proximal tibia that dynamically increased with increased flexion angle. Additionally, the DF brace applied

  11. Subspace based adaptive denoising of surface EMG from neurological injury patients

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Ying, Dongwen; Zev Rymer, William; Zhou, Ping

    2014-10-01

    Objective: After neurological injuries such as spinal cord injury, voluntary surface electromyogram (EMG) signals recorded from affected muscles are often corrupted by interferences, such as spurious involuntary spikes and background noises produced by physiological and extrinsic/accidental origins, imposing difficulties for signal processing. Conventional methods did not well address the problem caused by interferences. It is difficult to mitigate such interferences using conventional methods. The aim of this study was to develop a subspace-based denoising method to suppress involuntary background spikes contaminating voluntary surface EMG recordings. Approach: The Karhunen-Loeve transform was utilized to decompose a noisy signal into a signal subspace and a noise subspace. An optimal estimate of EMG signal is derived from the signal subspace and the noise power. Specifically, this estimator is capable of making a tradeoff between interference reduction and signal distortion. Since the estimator partially relies on the estimate of noise power, an adaptive method was presented to sequentially track the variation of interference power. The proposed method was evaluated using both semi-synthetic and real surface EMG signals. Main results: The experiments confirmed that the proposed method can effectively suppress interferences while keep the distortion of voluntary EMG signal in a low level. The proposed method can greatly facilitate further signal processing, such as onset detection of voluntary muscle activity. Significance: The proposed method can provide a powerful tool for suppressing background spikes and noise contaminating voluntary surface EMG signals of paretic muscles after neurological injuries, which is of great importance for their multi-purpose applications.

  12. Static Air Support Surfaces to Prevent Pressure Injuries: A Multicenter Cohort Study in Belgian Nursing Homes.

    PubMed

    Serraes, Brecht; Beeckman, Dimitri

    2016-01-01

    The aim of this study was to investigate the incidence and risk factors for developing pressure injuries (PIs) in patients placed on a static air support surfaces: mattress overlay, heel wedge, and seat cushion. Multicenter cohort study. The sample comprised 176 residents; their mean age was 87 (SD = 6.76) years; their mean Braden Scale score was 14 (SD = 2.54). The study was performed on a convenience sample of 6 nursing homes in Belgium. Data were collected on 23 care units. The primary outcome measure, cumulative PI incidence (category [stage] II-IV) over a 30-day observation period, was calculated. Pressure injury occurrence was defined according to the 2014 European and US National Pressure Injury Advisory panels, Pan Pacific Pressure Injury Alliance classification system. The PI incidence for category (stage) II-IV was 5.1%. Six residents (3.4%) developed a category II PI, and 3 (1.7%) developed a category III PI; no category IV ulcers occurred. No significant risk factors for category II-IV PIs were identified using multivariate logistic regression. Time of sitting in a chair was found to be a risk factor for development of nonblanchable erythema (category I PI) (odds ratio = 21.608; 95% confidence interval [CI], 20.510-22.812; P = .013). The median time to develop a category II-IV PI was 16 days (interquartile range = 2-26). The interrater reliability between the observations of the researcher and nurses on-site was almost perfect (0.86; 95% CI, 0.81-0.91). We found a low incidence of PIs when using a static air overlay mattress for patients at risk in a nursing home population. Static air support surfaces, alongside patient-tailored patient repositioning protocols, should be considered to prevent PIs in this patient population.

  13. Characterization of heterogeneous near-surface materials by joint stochastic approach

    NASA Astrophysics Data System (ADS)

    Girard, J.-F.; Roulle, A.; Grandjean, G.; Bitri, A.; Lalande, J.-M.

    2009-04-01

    Using several geophysical methods to better constrain a diagnosis is a standard approach in many field studies. Generally data of each method are individually inverted and a global geological / hydro-geological interpretation is realized as a second step from separated inversion results. Thereby, contributions and limitations of each method to final interpretation are integrated after the inversion processes. Consequently, the expertise of the one who performs the interpretation is decisive and its weight on the final result is difficult to quantify. In the end, reliability of geophysical interpretation is mainly limited by the problem of non-uniqueness of solution, on one hand because of equivalency of some models and intrinsic methods resolutions, and on the other hand because the links between geophysical parameters and rock physics properties in heterogeneous media are not so straight and do not allow to clearly discriminate between two materials (or state of weathering, or water saturation, etc…). Following the work of many authors in the past twenty years, we propose to jointly inverse several data types simultaneously in order to better constraint the inverse problem. We selected a set of geophysical methods, widely used to investigate the subsurface: vertical electrical sounding (VES), time domain electromagnetism (TEM), magnetic resonance sounding (MRS) and multi-channel analysis of surface waves (MASW). We particularly insist on how to objectively introduce the a-priori knowledge as an input in the algorithm. For a given geological environment, one can define a few hydrogeological facies each described by a statistical (normal, log-normal) distribution of classical geophysical parameters (electrical resistivity, water content, decay time, shear wave velocity). To explore the model space, we propose a stochastic approach based on the Metropolis algorithm in order to provide a statistical estimation on the result uncertainties (due to the data quality

  14. Joint Inversion of Receiver Function, Surface Wave Dispersion and ZH Ratio for Crustal Structure Based on Tikhonov Regularization

    NASA Astrophysics Data System (ADS)

    Yao, H.; Zhang, P.

    2015-12-01

    We proposed a joint iterative inversion method using receiver function, surface wave dispersion and ZH ratio data to better resolve 1-D crustal shear and compressional wave speed structure simultaneously. We implement a three-stage inversion strategy, which can take advantages of each dataset due to their complementary sensitivities to crust structures, to obtain structure information step by step using iterative linearized inversion approaches based on Tikhonov regularization of model parameters. We firstly invert surface wave dispersion and ZH ratio data to get 1-D shear velocity model, then incorporate P-wave receiver function data to obtain a much finer shear velocity model considering its high sensitivity to discontinuities. For the first two steps, the compressional velocity and density parameters are obtained from the shear velocity model using some empirical relationship. Finally, three datasets are further used to jointly invert for the compressional velocity structure based on the obtained shear velocity model. Synthetic tests show the superiority of joint inversion against separate inversion using only one or two datasets. They also demonstrate that the three-stage inversion strategy can make better use of different datasets to implement inversion physically and resolve finer crustal structure with more accuracy.

  15. Microstructure and properties of weld joint during 10 kW laser welding with surface-active element sulfur

    NASA Astrophysics Data System (ADS)

    Li, Shichun; Deng, Zhaohui; Deng, Hui; Xu, Wei

    2017-12-01

    The present work has been focused on the effects of surface-active element sulfur on welding properties during 10 kW high power laser welding of 304 stainless steel thick plate. Molten pool behavior, morphology feature of sulfide inclusions, metallographic structures, XRD patterns, microhardness, potentiodynamic polarization curves and pitted surface have been investigated and discussed. The results indicated that the added sulfur powder improved the weld depth by increasing molten metal fluidity, elongating molten pool and promoting heat transmission. The observed sulfide inclusions had small particle size of 0.65 μm in average and were distributed sparsely in weld joint. The WWS (weld joint with sulfur powder) had higher δ-ferrite content and finer grain size than the WWOS (weld joint without sulfur powder) and BM (base metal) due to the effects of sulfide inclusions on crystallizing process. The preferred orientations of γ-austenite along the (200) and (220) directions were promoted both in WWS and WWOS. Fine grain size and high δ-ferrite content led to high microhardness. The WWS had the highest microhardness among all the specimens. The WWOS and BM had a similar corrosion resistance. By comprehensive comparison, the WWS had a relative lower corrosion resistance than others, since sulfide inclusions in WWS not only had some benefits but also had some bad effects on corrosion property.

  16. Prediction of gait outcome with the knee-ankle-foot orthosis with medial hip joint in patients with spinal cord injuries: a study using recursive partitioning analysis.

    PubMed

    Suzuki, T; Sonoda, S; Saitoh, E; Onogi, K; Fujino, H; Teranishi, T; Oyobe, T; Katoh, M; Ohtsuka, K

    2007-01-01

    Retrospective study of the degree of gait independence achieved by persons with spinal cord injury (SCI) using knee-ankle-foot orthosis with a medial single hip joint (MSH-KAFO). To examine the effects of the neurological level, degree of paresis, age, and inhibitory physical/other factors on the gait with a MSH-KAFO in patients with SCIs. Three university hospitals and two rehabilitation hospitals in Japan. The 45 patients (36 men, nine women) examined included 10 with injuries in the cervical cord between C6 and C8 (group C), 20 with injuries in the upper-middle thoracic cord between T4 and T10 (group UT), and 15 with injuries in the lower thoracic-lumbar cord between T12 and L1 (group TL). Mean age was 34.0 years (range 16-68 years). Of these patients, 13 used the Walkabout, four used the gear joint, and 28 used the Primewalk as the medial hip joint. Recursive partitioning, which predicted the final status of gait from the level, degree of paresis, age, and inhibitory factors, was performed, and a decision tree for gait was constructed. Inhibitory factors were spasticity, involuntary spasms or muscle contractions, pain, contracture, weakness of the upper extremities, and decreased motivation to perform gait exercise. The degree of gait independence was rated on the following five-point scale: outdoor independent gait (5 points), indoor independent gait (4 points), indoor supervised gait (3 points), indoor assisted gait (2 points), and gait within parallel bars (1 point). New branches were added to the decision tree for gait based on the clinical experience, thereby constructing a new decision tree. The coincident ratio between the value predicted on the basis of the decision tree of gait and the value actually observed was 53.3%. The coincident ratio between the value predicted on the basis of the modified decision tree of gait and the actually observed value was 68.9%. The results provide valuable information to medical teams that may assist prescription of

  17. [Case-control study on measurement of coracoclavicular and acromioclavicular ligament injuries during internal fixation operation for the treatment of fresh acromioclavicular joint dislocation of Tossy type III].

    PubMed

    Guan, Ting-Jin; Sun, Peng; Zheng, Liang-Guo; Qi, Xiang-Yang

    2014-01-01

    To study measurement methods of acromioclavicular and coracoclavicular ligament injuries,its therapeutic effects and complications during internal fixation operation for the treatment of fresh acromioclavicular joint dislocations of Tossy type III. From July 2003 to May 2012,127 patients with acromioclavicular joint dislocations of Tossy type III were treated with wire fixation from coracoid process to clavicle or hook-plate fixation. The patients were divided into group A (63 cases) and group B (64 cases) according to whether acromioclavicular ligament and coracoclavicular ligament were repaired or not. In group A (ligaments repaired), there were 39 males and 24 females with an average age of (33.25 +/- 8.46) years old (ranged from 17 to 59 years). And in group B (no ligaments repaired), there were 41 males and 23 females with an average age of (34.10 +/- 7.19) years (ranged from 19 to 57 years). The operation times, intraoperative blood loss, postoperative infections, internal fixation failure, recurrence and other complications, together with therapeutic effects were compared between two groups. The outcome was analyzed according to Karlsson standard. In group A, 54 patients got an excellent result and 9 good according to Karlsson standard;the average operative time was (55.90 +/- 26.56) min; the average intraoperative bleeding amount was (99.80 +/- 50.30) ml; 1 patient had wire broken without re-dislocation at 16 weeks after operation, 3 patients got wound fat liquefaction and recovered after treatment, 1 patient had pain after shoulder joint motion and pain disappeared after implants were taken out. In group B, 52 patients got an excellent result and 12 good according to Karlsson standard; the average operative time was (49.50 +/- 23.14) min; the average intraoperative bleeding amount was (87.30 +/- 46.41) ml; 2 patients got wound fat liquefaction, and 2 patients had pain after shoulder joint motion. All the patients were followed up, and the duration ranged

  18. Effects of a shoulder injury prevention strength training program on eccentric external rotator muscle strength and glenohumeral joint imbalance in female overhead activity athletes.

    PubMed

    Niederbracht, Yvonne; Shim, Andrew L; Sloniger, Mark A; Paternostro-Bayles, Madeline; Short, Thomas H

    2008-01-01

    Imbalance of the eccentrically-activated external rotator cuff muscles versus the concentrically-activated internal rotator cuff muscles is a primary risk factor for glenohumeral joint injuries in overhead activity athletes. Nonisokinetic dynamometer based strength training studies, however, have focused exclusively on resulting concentric instead of applicable eccentric strength gains of the external rotator cuff muscles. Furthermore, previous strength training studies did not result in a reduction in glenoumeral joint muscle imbalance, thereby suggesting that currently used shoulder strength training programs do not effectively reduce the risk of shoulder injury to the overhead activity athlete. Two collegiate women tennis teams, consisting of 12 women, participated in this study throughout their preseason training. One team (n = 6) participated in a 5-week, 4 times a week, external shoulder rotator muscle strength training program next to their preseason tennis training. The other team (n = 6) participated in a comparable preseason tennis training program, but did not conduct any upper body strength training. Effects of this strength training program were evaluated by comparing pre- and posttraining data of 5 maximal eccentric external immediately followed by concentric internal contractions on a Kin-Com isokinetic dynamometer (Chattecx Corp., Hixson, Tennessee). Overall, the shoulder strength training program significantly increased eccentric external total work without significant effects on concentric internal total work, concentric internal mean peak force, or eccentric external mean peak force. In conclusion, by increasing the eccentric external total exercise capacity without a subsequent increase in the concentric internal total exercise capacity, this strength training program potentially decreases shoulder rotator muscle imbalances and the risk for shoulder injuries to overhead activity athletes.

  19. Short- and long-term changes in joint co-contraction associated with motor learning as revealed from surface EMG.

    PubMed

    Osu, Rieko; Franklin, David W; Kato, Hiroko; Gomi, Hiroaki; Domen, Kazuhisa; Yoshioka, Toshinori; Kawato, Mitsuo

    2002-08-01

    In the field of motor control, two hypotheses have been controversial: whether the brain acquires internal models that generate accurate motor commands, or whether the brain avoids this by using the viscoelasticity of musculoskeletal system. Recent observations on relatively low stiffness during trained movements support the existence of internal models. However, no study has revealed the decrease in viscoelasticity associated with learning that would imply improvement of internal models as well as synergy between the two hypothetical mechanisms. Previously observed decreases in electromyogram (EMG) might have other explanations, such as trajectory modifications that reduce joint torques. To circumvent such complications, we required strict trajectory control and examined only successful trials having identical trajectory and torque profiles. Subjects were asked to perform a hand movement in unison with a target moving along a specified and unusual trajectory, with shoulder and elbow in the horizontal plane at the shoulder level. To evaluate joint viscoelasticity during the learning of this movement, we proposed an index of muscle co-contraction around the joint (IMCJ). The IMCJ was defined as the summation of the absolute values of antagonistic muscle torques around the joint and computed from the linear relation between surface EMG and joint torque. The IMCJ during isometric contraction, as well as during movements, was confirmed to correlate well with joint stiffness estimated using the conventional method, i.e., applying mechanical perturbations. Accordingly, the IMCJ during the learning of the movement was computed for each joint of each trial using estimated EMG-torque relationship. At the same time, the performance error for each trial was specified as the root mean square of the distance between the target and hand at each time step over the entire trajectory. The time-series data of IMCJ and performance error were decomposed into long-term components that

  20. Preliminary Results on Scandinavian Lithospheric Structure Revealed by Joint Analysis of Receiver Functions and Surface Wave Dispersion

    NASA Astrophysics Data System (ADS)

    Makushkina, Anna; Tkalčić, Hrvoje; Kim, Seongryong; Artemieva, Irina; Thybo, Hans

    2017-04-01

    Scandinavia is a very complicated region for the deep seismic imaging. It consists of highly heterogeneous domains, and little is known about its internal structure. This study aims at imaging the lithosphere of Scandinavia using continuous records from seismic stations temporary deployed across Norway and Sweden by ScanArray experiment in 2012-2016. The recorded waveforms are characterized by a relatively high level of noise and a relatively small amount of records with good signal-to-noise ratio suitable for receiver function (RF) analysis. To moderate this problem we use a large number of receivers that form a dense spatial network and a complementary dataset of surface wave dispersion curves. Comparison of the results obtained by different state-of-the-art techniques: a joint inversion of P- and S-wave RF and a joint inversion of P-wave RF and surface wave dispersion (SWD) (initially, group velocity curves were extracted from the global model LITHO1.0), revealed the presence of a low shear-wave velocity zone, however, different methods determine different depth for this zone. A joint inversion of P- and S-wave RFs, computed through an adaptive simulated annealing algorithm, gives the depth of 20 to 30 km, while a joint inversion of P-wave RF and SWD within the Bayesian hierarchical framework gives the depth of 10 to 20 km. To resolve this disagreement, we obtain path-averaged group velocity curves from ambient noise for our stations, which improves the results of the joint inversion of P-wave RF and SWD. To calculate group velocity at each station location, we first obtain the Rayleigh wave group velocity curves for station pairs located within the radius of 150 km from the station of interest. We then obtain an average dispersion curve from all the group velocity measurements in the area and calculate its standard deviation. This methodology gives good constraint on path-averaged SWD for the Bayesian joint inversion in the area of study as opposed to taking

  1. Sulforhodamine B interacts with albumin to lower surface tension and protect against ventilation injury of flooded alveoli.

    PubMed

    Kharge, Angana Banerjee; Wu, You; Perlman, Carrie E

    2015-02-01

    In the acute respiratory distress syndrome, alveolar flooding by proteinaceous edema liquid impairs gas exchange. Mechanical ventilation is used as a supportive therapy. In regions of the edematous lung, alveolar flooding is heterogeneous, and stress is concentrated in aerated alveoli. Ventilation exacerbates stress concentrations and injuriously overexpands aerated alveoli. Injury degree is proportional to surface tension, T. Lowering T directly lessens injury. Furthermore, as heterogeneous flooding causes the stress concentrations, promoting equitable liquid distribution between alveoli should, indirectly, lessen injury. We present a new theoretical analysis suggesting that liquid is trapped in discrete alveoli by a pressure barrier that is proportional to T. Experimentally, we identify two rhodamine dyes, sulforhodamine B and rhodamine WT, as surface active in albumin solution and investigate whether the dyes lessen ventilation injury. In the isolated rat lung, we micropuncture a surface alveolus, instill albumin solution, and obtain an area with heterogeneous alveolar flooding. We demonstrate that rhodamine dye addition lowers T, reduces ventilation-induced injury, and facilitates liquid escape from flooded alveoli. In vitro we show that rhodamine dye is directly surface active in albumin solution. We identify sulforhodamine B as a potential new therapeutic agent for the treatment of the acute respiratory distress syndrome.

  2. Platelet-like Nanoparticles: Mimicking Shape, Flexibility, and Surface Biology of Platelets To Target Vascular Injuries

    PubMed Central

    2015-01-01

    Targeted delivery of therapeutic and imaging agents in the vascular compartment represents a significant hurdle in using nanomedicine for treating hemorrhage, thrombosis, and atherosclerosis. While several types of nanoparticles have been developed to meet this goal, their utility is limited by poor circulation, limited margination, and minimal targeting. Platelets have an innate ability to marginate to the vascular wall and specifically interact with vascular injury sites. These platelet functions are mediated by their shape, flexibility, and complex surface interactions. Inspired by this, we report the design and evaluation of nanoparticles that exhibit platelet-like functions including vascular injury site-directed margination, site-specific adhesion, and amplification of injury site-specific aggregation. Our nanoparticles mimic four key attributes of platelets, (i) discoidal morphology, (ii) mechanical flexibility, (iii) biophysically and biochemically mediated aggregation, and (iv) heteromultivalent presentation of ligands that mediate adhesion to both von Willebrand Factor and collagen, as well as specific clustering to activated platelets. Platelet-like nanoparticles (PLNs) exhibit enhanced surface-binding compared to spherical and rigid discoidal counterparts and site-selective adhesive and platelet-aggregatory properties under physiological flow conditions in vitro. In vivo studies in a mouse model demonstrated that PLNs accumulate at the wound site and induce ∼65% reduction in bleeding time, effectively mimicking and improving the hemostatic functions of natural platelets. We show that both the biochemical and biophysical design parameters of PLNs are essential in mimicking platelets and their hemostatic functions. PLNs offer a nanoscale technology that integrates platelet-mimetic biophysical and biochemical properties for potential applications in injectable synthetic hemostats and vascularly targeted payload delivery. PMID:25318048

  3. Platelet-like nanoparticles: mimicking shape, flexibility, and surface biology of platelets to target vascular injuries.

    PubMed

    Anselmo, Aaron C; Modery-Pawlowski, Christa Lynn; Menegatti, Stefano; Kumar, Sunny; Vogus, Douglas R; Tian, Lewis L; Chen, Ming; Squires, Todd M; Sen Gupta, Anirban; Mitragotri, Samir

    2014-11-25

    Targeted delivery of therapeutic and imaging agents in the vascular compartment represents a significant hurdle in using nanomedicine for treating hemorrhage, thrombosis, and atherosclerosis. While several types of nanoparticles have been developed to meet this goal, their utility is limited by poor circulation, limited margination, and minimal targeting. Platelets have an innate ability to marginate to the vascular wall and specifically interact with vascular injury sites. These platelet functions are mediated by their shape, flexibility, and complex surface interactions. Inspired by this, we report the design and evaluation of nanoparticles that exhibit platelet-like functions including vascular injury site-directed margination, site-specific adhesion, and amplification of injury site-specific aggregation. Our nanoparticles mimic four key attributes of platelets, (i) discoidal morphology, (ii) mechanical flexibility, (iii) biophysically and biochemically mediated aggregation, and (iv) heteromultivalent presentation of ligands that mediate adhesion to both von Willebrand Factor and collagen, as well as specific clustering to activated platelets. Platelet-like nanoparticles (PLNs) exhibit enhanced surface-binding compared to spherical and rigid discoidal counterparts and site-selective adhesive and platelet-aggregatory properties under physiological flow conditions in vitro. In vivo studies in a mouse model demonstrated that PLNs accumulate at the wound site and induce ∼65% reduction in bleeding time, effectively mimicking and improving the hemostatic functions of natural platelets. We show that both the biochemical and biophysical design parameters of PLNs are essential in mimicking platelets and their hemostatic functions. PLNs offer a nanoscale technology that integrates platelet-mimetic biophysical and biochemical properties for potential applications in injectable synthetic hemostats and vascularly targeted payload delivery.

  4. Are movement disorders and sensorimotor injuries pathologic synergies? When normal multi-joint movement synergies become pathologic.

    PubMed

    Santello, Marco; Lang, Catherine E

    2014-01-01

    The intact nervous system has an exquisite ability to modulate the activity of multiple muscles acting at one or more joints to produce an enormous range of actions. Seemingly simple tasks, such as reaching for an object or walking, in fact rely on very complex spatial and temporal patterns of muscle activations. Neurological disorders such as stroke and focal dystonia affect the ability to coordinate multi-joint movements. This article reviews the state of the art of research of muscle synergies in the intact and damaged nervous system, their implications for recovery and rehabilitation, and proposes avenues for research aimed at restoring the nervous system's ability to control movement.

  5. Brain-derived neurotrophic factor is upregulated in the cervical dorsal root ganglia and spinal cord and contributes to the maintenance of pain from facet joint injury in the rat.

    PubMed

    Kras, Jeffrey V; Weisshaar, Christine L; Quindlen, Julia; Winkelstein, Beth A

    2013-10-01

    The facet joint is commonly associated with neck and low back pain and is susceptible to loading-induced injury. Although tensile loading of the cervical facet joint has been associated with inflammation and neuronal hyperexcitability, the mechanisms of joint loading-induced pain remain unknown. Altered brain-derived neurotrophic factor (BDNF) levels are associated with a host of painful conditions, but the role of BDNF in loading-induced joint pain remains undefined. Separate groups of rats underwent a painful cervical facet joint distraction or a sham procedure. Bilateral forepaw mechanical hypersensitivity was assessed and BDNF mRNA and protein levels were quantified in the dorsal root ganglion (DRG) and spinal cord at days 1 and 7. Facet joint distraction induced significant (P < 0.001) mechanical hypersensitivity at both time points. Painful joint distraction did not alter BDNF mRNA in the DRG compared with sham levels but did significantly increase (P < 0.016) BDNF protein expression over sham in the DRG at day 7. Painful distraction also significantly increased BDNF mRNA (P = 0.031) and protein expression (P = 0.047) over sham responses in the spinal cord at day 7. In a separate study, intrathecal administration of the BDNF-sequestering molecule trkB-Fc on day 5 after injury partially attenuated behavioral sensitivity after joint distraction and reduced pERK in the spinal cord at day 7 (P < 0.045). Changes in BDNF after painful facet joint injury and the effect of spinal BDNF sequestration in partially reducing pain suggest that BDNF signaling contributes to the maintenance of loading-induced facet pain but that additional cellular responses are also likely involved. Copyright © 2013 Wiley Periodicals, Inc.

  6. A Nondestructive Evaluation Method: Measuring the Fixed Strength of Spot-Welded Joint Points by Surface Electrical Resistivity.

    PubMed

    Shimamoto, Akira; Yamashita, Keitaro; Inoue, Hirofumi; Yang, Sung-Mo; Iwata, Masahiro; Ike, Natsuko

    2013-04-01

    Destructive tests are generally applied to evaluate the fixed strength of spot-welding nuggets of zinc-plated steel (which is a widely used primary structural material for automobiles). These destructive tests, however, are expensive and time-consuming. This paper proposes a nondestructive method for evaluating the fixed strength of the welded joints using surface electrical resistance. A direct current nugget-tester and probes have been developed by the authors for this purpose. The proposed nondestructive method uses the relative decrease in surface electrical resistance, α. The proposed method also considers the effect of the corona bond. The nugget diameter is estimated by two factors: RQuota, which is calculated from variation of resistance, and a constant that represents the area of the corona bond. Since the maximum tensile strength is correlated with the nugget diameter, it can be inferred from the estimated nugget diameter. When appropriate measuring conditions for the surface electrical resistance are chosen, the proposed method can effectively evaluate the fixed strength of the spot-welded joints even if the steel sheet is zinc-plated.

  7. The impact of surface and geometry on coefficient of friction of artificial hip joints.

    PubMed

    Choudhury, Dipankar; Vrbka, Martin; Mamat, Azuddin Bin; Stavness, Ian; Roy, Chanchal K; Mootanah, Rajshree; Krupka, Ivan

    2017-08-01

    Coefficient of friction (COF) tests were conducted on 28-mm and 36-mm-diameter hip joint prostheses for four different material combinations, with or without the presence of Ultra High Molecular Weight Polyethylene (UHMWPE) particles using a novel pendulum hip simulator. The effects of three micro dimpled arrays on femoral head against a polyethylene and a metallic cup were also investigated. Clearance played a vital role in the COF of ceramic on polyethylene and ceramic on ceramic artificial hip joints. Micro dimpled metallic femoral heads yielded higher COF against a polyethylene cup; however, with metal on metal prostheses the dimpled arrays significantly reduced the COF. In situ images revealed evidence that the dimple arrays enhanced film formation, which was the main mechanism that contributed to reduced friction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. SUSTAINING NAVAL SURFACE COMBATANT VERTICAL LAUNCH SYSTEM MUNITIONS DURING JOINT OPERATIONS

    DTIC Science & Technology

    2017-04-21

    the Navy should develop a balanced logistics force. 15. SUBJECT TERMS MK 41 Vertical Launch System, Naval Logistics, Underway Replenishment, Joint...to gain increased agility in conducting prolonged combat operations at sea, the Navy should develop a balanced logistics and auxiliary tender force...order to minimize the possibility of submarine attack. Success depended upon balancing the distance required to minimize further enemy attack with

  9. Mutual influence of Tweens and dodecyl pyridinium chloride upon their joint adsorption on a surface of paraffin

    NASA Astrophysics Data System (ADS)

    Streltsova, E. A.; Mazuryk, A. A.

    2015-05-01

    The mutual influence of Tweens (Tween-20, Tween-40, Tween-60, Tween-80) and dodecyl pyridinium chloride (DDPC) upon their joint adsorption on the paraffin surface is studied using different molar ratios of components in a bulk aqueous solution. It is shown that both synergistic and antagonistic effects are observed upon the adsorption of cationic and nonionic surfactants from the mixed solutions. The compositions of mixed adsorption layers and the parameters of intermolecular interaction between surfactants of different natures are calculated. A possible mechanism is proposed for the adsorption process.

  10. Estimation of continuous multi-DOF finger joint kinematics from surface EMG using a multi-output Gaussian Process.

    PubMed

    Ngeo, Jimson; Tamei, Tomoya; Shibata, Tomohiro

    2014-01-01

    Surface electromyographic (EMG) signals have often been used in estimating upper and lower limb dynamics and kinematics for the purpose of controlling robotic devices such as robot prosthesis and finger exoskeletons. However, in estimating multiple and a high number of degrees-of-freedom (DOF) kinematics from EMG, output DOFs are usually estimated independently. In this study, we estimate finger joint kinematics from EMG signals using a multi-output convolved Gaussian Process (Multi-output Full GP) that considers dependencies between outputs. We show that estimation of finger joints from muscle activation inputs can be improved by using a regression model that considers inherent coupling or correlation within the hand and finger joints. We also provide a comparison of estimation performance between different regression methods, such as Artificial Neural Networks (ANN) which is used by many of the related studies. We show that using a multi-output GP gives improved estimation compared to multi-output ANN and even dedicated or independent regression models.

  11. The effect of videotape augmented feedback on drop jump landing strategy: Implications for anterior cruciate ligament and patellofemoral joint injury prevention.

    PubMed

    Munro, Allan; Herrington, Lee

    2014-10-01

    Modification of high-risk movement strategies such as dynamic knee valgus is key to the reduction of anterior cruciate ligament (ACL) and patellofemoral joint (PFJ) injuries. Augmented feedback, which includes video and verbal feedback, could offer a quick, simple and effective alternative to training programs for altering high-risk movement patterns. It is not clear whether feedback can reduce dynamic knee valgus measured using frontal plane projection angle (FPPA). Vertical ground reaction force (vGRF), two-dimensional FPPA of the knee, contact time and jump height of 20 recreationally active university students were measured during a drop jump task pre- and post- an augmented feedback intervention. A control group of eight recreationally active university students were also studied at baseline and repeat test. There was a significant reduction in vGRF (p=0.033), FPPA (p<0.001) and jump height (p<0.001) and an increase in contact time (p<0.001) post feedback in the intervention group. No changes were evident in the control group. Augmented feedback leads to significant decreases in vGRF, FPPA and contact time which may help to reduce ACL and PFJ injury risk. However, these changes may result in decreased performance. Augmented feedback reduces dynamic knee valgus, as measured via FPPA, and forces experienced during the drop jump task and therefore could be used as a tool for helping decrease ACL and PFJ injury risk prior to, or as part of, the implementation of injury prevention training programs. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. A review of metallic, ceramic and surface-treated metals used for bearing surfaces in human joint replacements.

    PubMed

    Dearnley, P A

    1999-01-01

    A review of established and advanced materials used for the bearing surfaces of total hip replacements (THRs), their standards, methods of manufacture and corrosion testing is presented. Some account is also taken of parallel developments in femoral components used in total knee replacements (TKRs). Metallic, ceramic and surface-modified metallic materials are separately reviewed, but wherever possible common practices are collated. Coated implant bearing surfaces are in an advanced state of development and some designs are receiving clinical evaluation. To date, however, no standard methods of manufacturing and testing these materials have been agreed. Accordingly, corrosion and other key quality test methods suitable for surface-modified implant bearing materials are reviewed.

  13. Shoe-surface friction influences movement strategies during a sidestep cutting task: implications for anterior cruciate ligament injury risk.

    PubMed

    Dowling, Ariel V; Corazza, Stefano; Chaudhari, Ajit M W; Andriacchi, Thomas P

    2010-03-01

    Increasing the coefficient of friction of the shoe-surface interaction has been shown to lead to increased incidence of anterior cruciate ligament (ACL) injuries, but the causes for this increase are unknown. Previous studies indicate that specific biomechanical measures during landing are associated with an increased risk for ACL injury. At foot contact during a sidestep cutting task, subjects use different movement strategies for shoe-surface conditions with a high coefficient of friction (COF) relative to a low friction condition. Specifically, the study tested for significant differences in knee kinematics, external knee moments, and the position of the center of mass for different COFs. Controlled laboratory study. Twenty-two healthy subjects (11 male) were evaluated performing a 30 degrees sidestep cutting task on a low friction surface (0.38) and a high friction surface (0.87) at a constant speed. An 8-camera markerless motion capture system combined with 2 force plates was used to measure full-body kinematics, kinetics, and center of mass. At foot contact, subjects had a lower knee flexion angle (P = .01), lower external knee flexion moment (P < .001), higher external knee valgus moment (P < .001), and greater medial distance of the center of mass from the support limb (P < .001) on the high friction surface relative to the low friction surface. The high COF shoe-surface condition was associated with biomechanical conditions that can increase the risk of ACL injury. The higher incidence of ACL injury observed on high friction surfaces could be a result of these biomechanical changes. The differences in the biomechanical variables were the result of an anticipated stimulus due to different surface friction, with other conditions remaining constant. The risk analysis of ACL injury should consider the biomechanical movement changes that occur for a shoe-surface condition with high friction.

  14. The quality of bone surfaces may govern the use of model based fluoroscopy in the determination of joint laxity.

    PubMed

    Moewis, P; Wolterbeek, N; Diederichs, G; Valstar, E; Heller, M O; Taylor, W R

    2012-12-01

    The assessment of knee joint laxity is clinically important but its quantification remains elusive. Calibrated, low dosage fluoroscopy, combined with registered surfaces and controlled external loading may offer possible solutions for quantifying relative tibio-femoral motion without soft tissue artefact, even in native joints. The aim of this study was to determine the accuracy of registration using CT and MRI derived 3D bone models, as well as metallic implants, to 2D single-plane fluoroscopic datasets, to assess their suitability for examining knee joint laxity. Four cadaveric knees and one knee implant were positioned using a micromanipulator. After fluoroscopy, the accuracy of registering each surface to the 2D fluoroscopic images was determined by comparison against known translations from the micromanipulator measurements. Dynamic measurements were also performed to assess the relative tibio-femoral error. For CT and MRI derived 3D femur and tibia models during static testing, the in-plane error was 0.4 mm and 0.9 mm, and out-of-plane error 2.6 mm and 9.3 mm respectively. For metallic implants, the in-plane error was 0.2 mm and out-of-plane error 1.5 mm. The relative tibio-femoral error during dynamic measurements was 0.9 mm, 1.2 mm and 0.7 mm in-plane, and 3.9 mm, 10.4 mm and 2.5 mm out-of-plane for CT and MRI based models and metallic implants respectively. The rotational errors ranged from 0.5° to 1.9° for CT, 0.5-4.3° for MRI and 0.1-0.8° for metallic implants. The results of this study indicate that single-plane fluoroscopic analysis can provide accurate information in the investigation of knee joint laxity, but should be limited to static or quasi-static evaluations when assessing native bones, where possible. With this knowledge of registration accuracy, targeted approaches for the determination of tibio-femoral laxity could now determine objective in vivo measures for the identification of ligament reconstruction candidates as well as improve our

  15. LOGISMOS—Layered Optimal Graph Image Segmentation of Multiple Objects and Surfaces: Cartilage Segmentation in the Knee Joint

    PubMed Central

    Zhang, Xiangmin; Williams, Rachel; Wu, Xiaodong; Anderson, Donald D.; Sonka, Milan

    2011-01-01

    A novel method for simultaneous segmentation of multiple interacting surfaces belonging to multiple interacting objects, called LOGISMOS (layered optimal graph image segmentation of multiple objects and surfaces), is reported. The approach is based on the algorithmic incorporation of multiple spatial inter-relationships in a single n-dimensional graph, followed by graph optimization that yields a globally optimal solution. The LOGISMOS method’s utility and performance are demonstrated on a bone and cartilage segmentation task in the human knee joint. Although trained on only a relatively small number of nine example images, this system achieved good performance. Judged by dice similarity coefficients (DSC) using a leave-one-out test, DSC values of 0.84 ± 0.04, 0.80 ± 0.04 and 0.80 ± 0.04 were obtained for the femoral, tibial, and patellar cartilage regions, respectively. These are excellent DSC values, considering the narrow-sheet character of the cartilage regions. Similarly, low signed mean cartilage thickness errors were obtained when compared to a manually-traced independent standard in 60 randomly selected 3-D MR image datasets from the Osteoarthritis Initiative database—0.11 ± 0.24, 0.05 ± 0.23, and 0.03 ± 0.17 mm for the femoral, tibial, and patellar cartilage thickness, respectively. The average signed surface positioning errors for the six detected surfaces ranged from 0.04 ± 0.12 mm to 0.16 ± 0.22 mm. The reported LOGISMOS framework provides robust and accurate segmentation of the knee joint bone and cartilage surfaces of the femur, tibia, and patella. As a general segmentation tool, the developed framework can be applied to a broad range of multiobject multisurface segmentation problems. PMID:20643602

  16. MRI versus radiography of acromioclavicular joint dislocation.

    PubMed

    Nemec, Ursula; Oberleitner, Gerhard; Nemec, Stefan F; Gruber, Michael; Weber, Michael; Czerny, Christian; Krestan, Christian R

    2011-10-01

    Acromioclavicular joint injuries are usually diagnosed by clinical and radiographic assessment with the Rockwood classification, which is crucial for treatment planning. In view of the implementation of MRI for visualization of the acromioclavicular joint, the purpose of this study was to describe the MRI findings of acromioclavicular joint dislocation in comparison with the radiographic findings. Forty-four patients with suspected unilateral acromioclavicular joint dislocation after acute trauma were enrolled in this prospective study. All patients underwent digital radiography and 1-T MRI with a surface phased-array coil. MRI included coronal proton density-weighted turbo spin-echo and coronal 3D T1-weighted fast field-echo water-selective sequences. The Rockwood classification was used to assess acromioclavicular joint injuries at radiography and MRI. An adapted Rockwood classification was used for MRI evaluation of the acromioclavicular joint ligaments. The classifications of acromioclavicular joint dislocations diagnosed with radiography and MRI were compared. Among 44 patients with Rockwood type I-IV injuries on radiographs, classification on radiographs and MR images was concordant in 23 (52.2%) patients. At MRI, the injury was reclassified to a less severe type in 16 (36.4%) patients and to a more severe type in five (11.4%) patients. Compared with the findings according to the original Rockwood system, with the adapted system that included MRI findings, additional ligamentous lesions were found in 11 (25%) patients. In a considerable number of patients, the MRI findings change the Rockwood type determined with radiography. In addition to clinical assessment and radiography, MRI may yield important findings on ligaments that may influence management.

  17. Surface anatomy of the inferior epigastric artery in relation to laparoscopic injury.

    PubMed

    Epstein, J; Arora, A; Ellis, H

    2004-07-01

    The inferior epigastric artery (IEA) is at risk of injury in laparoscopic surgery. Current descriptions of the course of the IEA do not provide surface landmarks useful to the surgeon. This study aimed to define surface relations and propose guidelines for safer trocar placement. The posterior surfaces of the anterior abdominal walls of 30 preserved cadavers were dissected. The surface anatomy of 60 IEAs and their branches were defined. At the level of the anterior superior iliac spine (ASIS), the IEA is 38% +/- 18% (95% confidence interval [CI]) from the midline to the ASIS. At the mid-inguinal point the relation is 40% +/- 17% and at the umbilicus 40% +/- 22%. The pattern of branches is highly variable. Although giving guidelines for trocar insertion can be treacherous, we found the following to be of value: 1) the midline is avascular; 2) the main stem of the IEA will be avoided if trocars are inserted more than two-thirds of the distance along a horizontal line between the midline and the ASIS; and 3) IEA branches are least frequently found in the lowest part of the abdomen lateral to the artery.

  18. An Overview of Surface Finishes and Their Role in Printed Circuit Board Solderability and Solder Joint Performance

    SciTech Connect

    Vianco, P.T.

    1998-10-15

    A overview has been presented on the topic of alternative surface finishes for package I/Os and circuit board features. Aspects of processability and solder joint reliability were described for the following coatings: baseline hot-dipped, plated, and plated-and-fused 100Sn and Sn-Pb coatings; Ni/Au; Pd, Ni/Pd, and Ni/Pd/Au finishes; and the recently marketed immersion Ag coatings. The Ni/Au coatings appear to provide the all-around best option in terms of solderability protection and wire bondability. Nickel/Pal ftishes offer a slightly reduced level of performance in these areas that is most likely due to variable Pd surface conditions. It is necessmy to minimize dissolved Au or Pd contents in the solder material to prevent solder joint embrittlement. Ancillary aspects that included thickness measurement techniques; the importance of finish compatibility with conformal coatings and conductive adhesives; and the need for alternative finishes for the processing of non-Pb bearing solders were discussed.

  19. Improved characterization of combat injury.

    PubMed

    Champion, Howard R; Holcomb, John B; Lawnick, Mary M; Kelliher, Timothy; Spott, Mary Ann; Galarneau, Michael R; Jenkins, Donald H; West, Susan A; Dye, Judy; Wade, Charles E; Eastridge, Brian J; Blackbourne, Lorne H; Shair, Ellen Kalin

    2010-05-01

    Combat injury patterns differ from civilian trauma in that the former are largely explosion-related, comprising multiple mechanistic and fragment injuries and high-kinetic-energy bullets. Further, unlike civilians, U.S. armed forces combatants are usually heavily protected with helmets and Kevlar body armor with ceramic plate inserts. Searchable databases providing actionable, statistically valid knowledge of body surface entry wounds and resulting organ injury severity are essential to understanding combat trauma. Two tools were developed to address these unique aspects of combat injury: (1) the Surface Wound Mapping (SWM) database and Surface Wound Analysis Tool (SWAT) software that were developed to generate 3D density maps of point-of-surface wound entry and resultant anatomic injury severity; and (2) the Abbreviated Injury Scale (AIS) 2005-Military that was developed by a panel of military trauma surgeons to account for multiple injury etiology from explosions and other high-kinetic- energy weapons. Combined data from the Joint Theater Trauma Registry, Navy/Marine Combat Trauma Registry, and the Armed Forces Medical Examiner System Mortality Trauma Registry were coded in AIS 2005-Military, entered into the SWM database, and analyzed for entrance site and wounding path. When data on 1,151 patients, who had a total of 3,500 surface wounds and 12,889 injuries, were entered into SWM, surface wounds averaged 3.0 per casualty and injuries averaged 11.2 per casualty. Of the 3,500 surface wounds, 2,496 (71%) were entrance wounds with 6,631 (51%) associated internal injuries, with 2.2 entrance wounds and 5.8 associated injuries per casualty (some details cannot be given because of operational security). Crude deaths rates were calculated using Maximum AIS-Military. These new tools have been successfully implemented to describe combat injury, mortality, and distribution of wounds and associated injuries. AIS 2005-Military is a more precise assignment of severity to

  20. Are Movement Disorders and Sensorimotor Injuries Pathologic Synergies? When Normal Multi-Joint Movement Synergies Become Pathologic

    PubMed Central

    Santello, Marco; Lang, Catherine E.

    2015-01-01

    The intact nervous system has an exquisite ability to modulate the activity of multiple muscles acting at one or more joints to produce an enormous range of actions. Seemingly simple tasks, such as reaching for an object or walking, in fact rely on very complex spatial and temporal patterns of muscle activations. Neurological disorders such as stroke and focal dystonia affect the ability to coordinate multi-joint movements. This article reviews the state of the art of research of muscle synergies in the intact and damaged nervous system, their implications for recovery and rehabilitation, and proposes avenues for research aimed at restoring the nervous system’s ability to control movement. PMID:25610391

  1. Corrosion Behavior of Top and Bottom Surfaces for Single-Side and Double-Side Friction Stir Welded 7085-T7651 Aluminum Alloy Thick Plate Joints

    NASA Astrophysics Data System (ADS)

    Xu, Weifeng; Zhang, Wei; Wu, Xiaoli

    2017-03-01

    Thick plate joints of 7085-T7451 aluminum alloy were obtained through both single-side and double-side friction stir welding (SS or DS-FSW). The chloride ions effects on the corrosion behavior of the top and bottom surfaces of the joints were examined by cyclic potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). Results show that the corrosion susceptibility was suppressed significantly in the weld nugget zone, while the base material and heat-affected zone were prone to be corrosion attacked. For the SS-FSWed joint, the top surface showed a higher corrosion resistance than that of the bottom surface, but the larger corrosive heterogeneity was observed between the top and bottom surfaces compared with the two welds of DS-FSWed joint, which was confirmed by the morphology of corrosion attack. A deep insight on the microstructure of the joints indicates that the intermetallic particles played a key role in the corrosion behavior of the FSWed AA7085 aluminum alloy joints in chloride solution.

  2. Corrosion Behavior of Top and Bottom Surfaces for Single-Side and Double-Side Friction Stir Welded 7085-T7651 Aluminum Alloy Thick Plate Joints

    NASA Astrophysics Data System (ADS)

    Xu, Weifeng; Zhang, Wei; Wu, Xiaoli

    2017-01-01

    Thick plate joints of 7085-T7451 aluminum alloy were obtained through both single-side and double-side friction stir welding (SS or DS-FSW). The chloride ions effects on the corrosion behavior of the top and bottom surfaces of the joints were examined by cyclic potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). Results show that the corrosion susceptibility was suppressed significantly in the weld nugget zone, while the base material and heat-affected zone were prone to be corrosion attacked. For the SS-FSWed joint, the top surface showed a higher corrosion resistance than that of the bottom surface, but the larger corrosive heterogeneity was observed between the top and bottom surfaces compared with the two welds of DS-FSWed joint, which was confirmed by the morphology of corrosion attack. A deep insight on the microstructure of the joints indicates that the intermetallic particles played a key role in the corrosion behavior of the FSWed AA7085 aluminum alloy joints in chloride solution.

  3. Hepatitis B virus surface proteins accelerate cholestatic injury and tumor progression in Abcb4-knockout mice

    PubMed Central

    Churin, Yuri; Herebian, Diran; Mayatepek, Ertan; Köhler, Kernt; Gattenlöhner, Stefan; Stinn, Anne; Tschuschner, Annette; Roderfeld, Martin; Roeb, Elke

    2017-01-01

    Understanding of the pathophysiology of cholestasis associated carcinogenesis could challenge the development of new personalized therapeutic approaches and thus improve prognosis. Simultaneous damage might aggravate hepatic injury, induce chronic liver disease and even promote carcinogenesis. We aimed to study the effect of Hepatitis B virus surface protein (HBsAg) on cholestatic liver disease and associated carcinogenesis in a mouse model combining both impairments. Hybrids of Abcb4−/− and HBsAg transgenic mice were bred on fibrosis susceptible background BALB/c. Liver injury, serum bile acid concentration, hepatic fibrosis, and carcinogenesis were enhanced by the combination of simultaneous damage in line with activation of c-Jun N-terminal kinase (JNK), proto-oncogene c-Jun, and Signal transducer and activator of transcription 3 (STAT3). Activation of Protein Kinase RNA-like Endoplasmic Reticulum Kinase (PERK) and Eukaryotic translation initiation factor 2A (eIF2α) indicated unfolded protein response (UPR) in HBsAg-expressing mice and even in Abcb4−/− without HBsAg-expression. CONCLUSION: Cholestasis-induced STAT3- and JNK-pathways may predispose HBsAg-associated tumorigenesis. Since STAT3- and JNK-activation are well characterized critical regulators for tumor promotion, the potentiation of their activation in hybrids suggests an additive mechanism enhancing tumor incidence. PMID:28881751

  4. Surface modifications of nylon/carbon fiber composite for improving joint adhesion

    SciTech Connect

    Wu, R.; Liao, S.L.; Tong, T.S.; Young, J.T.

    1996-12-31

    Various methods were used to modify the nylon/carbon fiber composite surfaces, including grit blasting, flame and plasma pretreatments. The surfaces of nylon composites after pretreatments were characterized by contact angle measurements, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). XPS results show that several functional groups were formed after plasma and flame pretreatments. The scanning electron microscope (SEM) photographs suggest that the blasting pretreatment increased the surface roughness of nylon composites. All these surface pretreatments dramatically increased the lap shear strength if proper operation conditions were used. The reasons for the increase of lap shear strength were explained.

  5. Connectomic and Surface-Based Morphometric Correlates of Acute Mild Traumatic Brain Injury

    PubMed Central

    Dall'Acqua, Patrizia; Johannes, Sönke; Mica, Ladislav; Simmen, Hans-Peter; Glaab, Richard; Fandino, Javier; Schwendinger, Markus; Meier, Christoph; Ulbrich, Erika J.; Müller, Andreas; Jäncke, Lutz; Hänggi, Jürgen

    2016-01-01

    Reduced integrity of white matter (WM) pathways and subtle anomalies in gray matter (GM) morphology have been hypothesized as mechanisms in mild traumatic brain injury (mTBI). However, findings on structural brain changes in early stages after mTBI are inconsistent and findings related to early symptoms severity are rare. Fifty-one patients were assessed with multimodal neuroimaging and clinical methods exclusively within 7 days following mTBI and compared to 53 controls. Whole-brain connectivity based on diffusion tensor imaging was subjected to network-based statistics, whereas cortical surface area, thickness, and volume based on T1-weighted MRI scans were investigated using surface-based morphometric analysis. Reduced connectivity strength within a subnetwork of 59 edges located predominantly in bilateral frontal lobes was significantly associated with higher levels of self-reported symptoms. In addition, cortical surface area decreases were associated with stronger complaints in five clusters located in bilateral frontal and postcentral cortices, and in the right inferior temporal region. Alterations in WM and GM were localized in similar brain regions and moderately-to-strongly related to each other. Furthermore, the reduction of cortical surface area in the frontal regions was correlated with poorer attentive-executive performance in the mTBI group. Finally, group differences were detected in both the WM and GM, especially when focusing on a subgroup of patients with greater complaints, indicating the importance of classifying mTBI patients according to severity of symptoms. This study provides evidence that mTBI affects not only the integrity of WM networks by means of axonal damage but also the morphology of the cortex during the initial post-injury period. These anomalies might be greater in the acute period than previously believed and the involvement of frontal brain regions was consistently pronounced in both findings. The dysconnected subnetwork

  6. Pulsed shortwave diathermy and joint mobilizations for achieving normal elbow range of motion after injury or surgery with implanted metal: a case series.

    PubMed

    Draper, David O

    2014-01-01

    Regaining full, active range of motion (ROM) after trauma to the elbow is difficult. To report the cases of 6 patients who lacked full ROM in the elbow because of trauma. The treatment regimen was thermal pulsed shortwave diathermy and joint mobilizations. Case series. University therapeutic modalities laboratory. Six patients (5 women [83%], 1 man [17%]) lacked a mean active ROM of 24.5° of extension approximately 4.8 years after trauma or surgery. Treatment consisted of 20 minutes of pulsed shortwave diathermy at 800 pulses per second for 400 microseconds (40-48 W average power, 150 W peak power) applied to the cubital fossa, immediately followed by 7 to 8 minutes of joint mobilizations. After posttreatment ROM was recorded, ice was applied to the area for about 30 minutes. Changes in extension active ROM were assessed before and after each treatment. Once the patient achieved full, active ROM or failed to improve on 2 consecutive visits, he or she was discharged from the study. By the fifth treatment, 4 participants (67%) achieved normal extension active ROM, and 2 of the 4 (50%) exceeded the norm. Five participants (83%) returned to normal activities and full use of their elbows. One month later, the 5 participants had maintained, on average, (mean ± SD) 92% ± 6% of their final measurements. A combination of thermal pulsed shortwave diathermy and joint mobilizations was effective in restoring active ROM of elbow extension in 5 of the 6 patients (83%) who lacked full ROM after injury or surgery.

  7. Quantitative investigation of surface and subsurface fatigue cracks near rivets in riveted joints using acoustic, electron and optical microscopy

    NASA Astrophysics Data System (ADS)

    Connor, Zayna Marie

    2000-10-01

    Using scanning acoustic microscopy, optical microscopy and scanning electron microscopy, in conjunction with fractography of fractured surfaces, the crack formation and growth kinetics of subsurface fatigue cracks and surface breaking fatigue cracks near rivets have been characterized in detail in this research. The scanning acoustic microscope was used to quantitatively investigate subsurface fatigue cracks (even when they were very small) at and near countersunk rivets in riveted lap joint specimens that are similar to the riveted lap joints found in the fuselages of many aircraft. It was found that the maximum nominal applied stress influences the fatigue crack initiation and propagation behavior. Eyebrow type cracks develop at lower stresses and centerline cracks develop at higher stresses. At low stress ranges, the fatigue cracks initiate a short distance from the rivet at or near the hidden surface of the chamfered panel. At higher stress amplitudes, the cracks initiate at the blunt knife edge. Residual compressive stresses and fretting are suggested to play more important roles at lower stress ranges. Both types of cracks initiate in a shear mode but transform to tensile, mode I, cracks as they grow. This transition occurs much more rapidly at the higher stress amplitude. At both high and low stresses, the cracks are longer on the fayed surface of the panel than elsewhere. In a comparison of Alclad 2024-T3 and Alclad 2524-T3, it was found that the high purity aluminum alloy 2524 nucleates cracks at a greater number of cycles than the less pure aluminum alloy 2024. At high stress, crack initiation plays less of a roll and the 2024 alloy has a longer life. The scanning acoustic microscope enabled us to study subsurface fatigue cracks. The understanding gained from the characterization of the subsurface fatigue cracks will help in the modeling of crack initiation and growth in the riveted lap joint and will also aid in the improvement of NDE techniques for the

  8. Traumatic spinal cord injury caused by suspected hyperflexion of the atlantoaxial joint in a 10-year-old cat

    PubMed Central

    McLaughlin, Angela; Hammond, Gawain

    2015-01-01

    Case summary A 10-year-old cat presented 5 days after a traumatic event with acute recumbency followed by some clinical improvement. The neuroanatomical localisation was the C1–C5 spinal cord segments. Initial survey radiographs, including lateral flexed views, showed no convincing abnormalities. Magnetic resonance imaging (MRI) revealed a marked focal intramedullary lesion at the level of the dens and suspected oedema extending over C2–C3 vertebrae, suggesting early syrinx formation. The cat made an initial excellent recovery on restricted exercise without medical treatment. The MRI changes largely resolved on follow-up MRI 4 weeks later yet recurred following a relapse 4 months later. At this stage, a post-traumatic syrinx had developed. Moreover, the suspected atlantoaxial instability was finally diagnosed on radiography with fully flexed lateral views. A hyperflexion injury causing tearing of the atlantoaxial ligaments was considered most likely given the lack of malformations or fractures. The cat made a full recovery on conservative management. Relevance and novel information This is the first report of sequential MRI findings in a cat with atlantoaxial instability. Moreover, post-traumatic syringomyelia formation following atlantoaxial injury has not been reported. Sequential MRI aids in the diagnosis of hyperflexion injury if survey radiographs fail to identify atlantoaxial instability. PMID:28491364

  9. Measuring surface temperature and grading pathological changes of airway tissue in a canine model of inhalational thermal injury.

    PubMed

    Zhao, Ran; Di, La-na; Zhao, Xiao-zhuo; Wang, Cheng; Zhang, Guo-an

    2013-06-01

    Airway tissue shows unexpected invulnerability to heated air. The mechanisms of this phenomenon are open to debate. This study was designed to measure the surface temperatures at different locations of the airway, and to explore the relationship between the tissue's surface temperature and injury severity. Twenty dogs were randomly divided into four groups, including three experimental groups (six dogs in each) to inhale heated air at 70-80 °C (group I), 150-160 °C (group II) and 310-320 °C (group III) and a control group (two dogs, only for histological observation). Injury time was 20 min. Mucosal surface temperatures of the epiglottis (point A), cricoid cartilage (point B) and lower trachea (point C) were measured. Dogs in group I-III were divided into three subgroups (two in each), to be assayed at 12, 24 and 36 h after injury, respectively. For each dog, four tissue parts (epiglottis, larynx, lower trachea and terminal bronchiole) were microscopically observed and graded according to an original pathological scoring system (score range: 0-27). Surface temperatures of the airway mucosa increased slowly to 40.60±3.29 °C, and the highest peak temperature was 48.3 °C (group III, point A). The pathological score of burned tissues was 4.12±4.94 (0.0-18.0), suggesting slight to moderate injuries. Air temperature and airway location both influenced mucosal temperature and pathological scores very significantly, and there was a very significant positive correlation between tissue temperature and injury severity. Compared to the inhalational air hyperthermia, airway surface temperature was much lower, but was still positively correlated with thermal injury severity. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  10. Arm Injuries and Disorders

    MedlinePlus

    ... of muscles, joints, tendons, and other connective tissue. Injuries to any of these parts of the arm ... a fall, or an accident. Types of arm injuries include Tendinitis and bursitis Sprains Dislocations Broken bones ...

  11. Leg Injuries and Disorders

    MedlinePlus

    ... legs. Common leg injuries include sprains and strains, joint dislocations, and fractures. These injuries can affect the entire leg, or just the foot, ankle, knee, or hip. Certain diseases also lead to ...

  12. Physical-property-, lithology- and surface-geometry-based joint inversion using Pareto Multi-Objective Global Optimization

    NASA Astrophysics Data System (ADS)

    Bijani, Rodrigo; Lelièvre, Peter G.; Ponte-Neto, Cosme F.; Farquharson, Colin G.

    2017-05-01

    This paper is concerned with the applicability of Pareto Multi-Objective Global Optimization (PMOGO) algorithms for solving different types of geophysical inverse problems. The standard deterministic approach is to combine the multiple objective functions (i.e. data misfit, regularization and joint coupling terms) in a weighted-sum aggregate objective function and minimize using local (decent-based) smooth optimization methods. This approach has some disadvantages: (1) appropriate weights must be determined for the aggregate, (2) the objective functions must be differentiable and (3) local minima entrapment may occur. PMOGO algorithms can overcome these drawbacks but introduce increased computational effort. Previous work has demonstrated how PMOGO algorithms can overcome the first issue for single data set geophysical inversion, that is, the trade-off between data misfit and model regularization. However, joint inversion, which can involve many weights in the aggregate, has seen little study. The advantage of PMOGO algorithms for the other two issues has yet to be addressed in the context of geophysical inversion. In this paper, we implement a PMOGO genetic algorithm and apply it to physical-property-, lithology- and surface-geometry-based inverse problems to demonstrate the advantages of using a global optimization strategy. Lithological inversions work on a mesh but use integer model parameters representing rock unit identifiers instead of continuous physical properties. Surface geometry inversions change the geometry of wireframe surfaces that represent the contacts between discrete rock units. Despite the potentially high computational requirements of global optimization algorithms (compared to local), their application to realistically sized 2-D geophysical inverse problems is within reach of current capacity of standard computers. Furthermore, they open the door to geophysical inverse problems that could not otherwise be considered through traditional

  13. Physical property-, lithology- and surface geometry-based joint inversion using Pareto multi-objective global optimization

    NASA Astrophysics Data System (ADS)

    Bijani, Rodrigo; Lelièvre, Peter G.; Ponte-Neto, Cosme F.; Farquharson, Colin G.

    2017-02-01

    This paper is concerned with the applicability of Pareto Multi-Objective Global Optimization (PMOGO) algorithms for solving different types of geophysical inverse problems. The standard deterministic approach is to combine the multiple objective functions (i.e. data misfit, regularization and joint coupling terms) in a weighted-sum aggregate objective function and minimize using local (decent-based) smooth optimization methods. This approach has some disadvantages: 1) appropriate weights must be determined for the aggregate, 2) the objective functions must be differentiable, and 3) local minima entrapment may occur. PMOGO algorithms can overcome these drawbacks but introduce increased computational effort. Previous work has demonstrated how PMOGO algorithms can overcome the first issue for single data set geophysical inversion, i.e. the tradeoff between data misfit and model regularization. However, joint inversion, which can involve many weights in the aggregate, has seen little study. The advantage of PMOGO algorithms for the other two issues has yet to be addressed in the context of geophysical inversion. In this paper, we implement a PMOGO genetic algorithm and apply it to physical property-, lithology- and surface geometry-based inverse problems to demonstrate the advantages of using a global optimization strategy. Lithological inversions work on a mesh but use integer model parameters representing rock unit identifiers instead of continuous physical properties. Surface geometry inversions change the geometry of wireframe surfaces that represent the contacts between discrete rock units. Despite the potentially high computational requirements of global optimization algorithms (compared to local), their application to realistically-sized 2D geophysical inverse problems is within reach of current capacity of standard computers. Furthermore, they open the door to geophysical inverse problems that could not otherwise be considered through traditional optimization

  14. Crustal layering in northeastern Tibet: a case study based on joint inversion of receiver functions and surface wave dispersion

    NASA Astrophysics Data System (ADS)

    Deng, Yangfan; Shen, Weisen; Xu, Tao; Ritzwoller, Michael H.

    2015-10-01

    Recently constructed models of crustal structure across Tibet based on surface wave data display a prominent mid-crustal low velocity zone (LVZ) but are vertically smooth in the crust. Using six months of broad-band seismic data recorded at 22 stations arrayed approximately linearly over a 440 km observation profile across northeastern Tibet (from the Songpan-Ganzi block, through the Qaidam block, into the Qilian block), we perform a Bayesian Monte Carlo joint inversion of receiver function data with surface wave dispersion to address whether crustal layering is needed to fit both data sets simultaneously. On some intervals a vertically smooth crust is consistent with both data sets, but across most of the observation profile two types of layering are required: a discrete LVZ or high velocity zone (HVZ) formed by two discontinuities in the middle crust and a doublet Moho formed by two discontinuities from 45-50 km to 60-65 km depth connected by a linear velocity gradient in the lowermost crust. The final model possesses (1) a mid-crustal LVZ that extends from the Songpan-Ganzi block through the Kunlun suture into the Qaidam block consistent with partial melt and ductile flow and (2) a mid-crustal HVZ bracketing the south Qilian suture coincident with ultrahigh pressure metamorphic rocks at the surface. (3) Additionally, the model possesses a doublet Moho extending from the Qaidam to the Qilian blocks which probably reflects increased mafic content with depth in the lowermost crust perhaps caused by a vertical gradient of ecologitization. (4) Crustal thickness is consistent with a step-Moho that jumps discontinuously by 6 km from 63.8 km (±1.8 km) south of 35° to 57.8 km (±1.4 km) north of this point coincident with the northern terminus of the mid-crustal LVZ. These results are presented as a guide to future joint inversions across a much larger region of Tibet.

  15. Imaging of the Volcanic Island of Basse-Terre by Joint Inversion of Surface Wave, Travel Time and Gravimetric Data

    NASA Astrophysics Data System (ADS)

    Barnoud, A.; Coutant, O.; Bouligand, C.

    2016-12-01

    We aim at jointly inverting surface wave dispersion curves, earthquake travel times and gravimetric data to image the 3D structure of the volcanic island of Basse-Terre in Guadeloupe (Lesser Antilles). Imaging the 3D structure of this island is challenging, in particular due to the rough topography, the difficult access associated with the dense vegetation and the high level of seismic noise associated with tropical climate. The joint inversion of different types of data allows to derive a model compatible with all datasets, improving the resolution of the resulting model, due to the intrinsic sensitivities of the methods and to the different data coverages. Surface wave dispersion curves were obtained from ambient noise cross-correlations and provide seismic velocities with a good resolution in the upper 4 to 6 km. Travel times from the Lesser Antilles earthquake catalogue (CDSA/IPGP, Massin et al. 2013, Massin et al. 2014) are also included to improve the resolution at depth. Five datasets of terrestrial gravimetric data covering the whole island are available (Coron et al. 1975, Barthes et al. 1984, Gunawan 2005, Matthieu et al. 2011, Barnoud et al. 2016), constraining mostly the shallow lateral density variations. However coupling such datasets is not straightforward as it requires defining a coupling, a discretization and an inversion scheme adapted to the three methods. Our problem is coupled via the surface wave data and a P-wave velocity/density relationship (Carlson & Raskin 1984). We regularize the inverse problem using a Bayesian formalism (Tarantola & Valette 1982) and we discuss the advantages and limitations of two approaches to model the velocities of the subsurface: 1) a grid of nodes regularly spaced and 2) a Lagrangian interpolation on Gauss-Chebychev colocation nodes, equivalent to the use of a base of Chebychev polynomials (Boyd 2001). This work leads to the first 3D seismic velocity model of the island of Basse-Terre and therefore constitute a

  16. Lithospheric architecture of NE China from joint Inversions of receiver functions and surface wave dispersion through Bayesian optimisation

    NASA Astrophysics Data System (ADS)

    Sebastian, Nita; Kim, Seongryong; Tkalčić, Hrvoje; Sippl, Christian

    2017-04-01

    The purpose of this study is to develop an integrated inference on the lithospheric structure of NE China using three passive seismic networks comprised of 92 stations. The NE China plain consists of complex lithospheric domains characterised by the co-existence of complex geodynamic processes such as crustal thinning, active intraplate cenozoic volcanism and low velocity anomalies. To estimate lithospheric structures with greater detail, we chose to perform the joint inversion of independent data sets such as receiver functions and surface wave dispersion curves (group and phase velocity). We perform a joint inversion based on principles of Bayesian transdimensional optimisation techniques (Kim etal., 2016). Unlike in the previous studies of NE China, the complexity of the model is determined from the data in the first stage of the inversion, and the data uncertainty is computed based on Bayesian statistics in the second stage of the inversion. The computed crustal properties are retrieved from an ensemble of probable models. We obtain major structural inferences with well constrained absolute velocity estimates, which are vital for inferring properties of the lithosphere and bulk crustal Vp/Vs ratio. The Vp/Vs estimate obtained from joint inversions confirms the high Vp/Vs ratio ( 1.98) obtained using the H-Kappa method beneath some stations. Moreover, we could confirm the existence of a lower crustal velocity beneath several stations (eg: station SHS) within the NE China plain. Based on these findings we attempt to identify a plausible origin for structural complexity. We compile a high-resolution 3D image of the lithospheric architecture of the NE China plain.

  17. An analysis of specific lower extremity injury rates on grass and FieldTurf playing surfaces in National Football League Games: 2000-2009 seasons.

    PubMed

    Hershman, Elliott B; Anderson, Robert; Bergfeld, John A; Bradley, James P; Coughlin, Michael J; Johnson, Robert J; Spindler, Kurt P; Wojtys, Edward; Powell, John W

    2012-10-01

    Players in the National Football League (NFL) sustain injuries every season as the result of their participation. One factor associated with the rate of injury is the type of playing surface on which the players participate. There is no difference in the rate of knee sprains and ankle sprains during NFL games when comparing rates of those injuries during games played on natural grass surfaces with rates of those injuries during games played on the artificial surface FieldTurf. Descriptive epidemiology study. The NFL records injury and exposure (ie, game) data as part of its injury surveillance system. During the 2000-2009 NFL seasons, there were 2680 games (5360 team games) played on grass or artificial surfaces. Specifically, 1356 team games were played on FieldTurf and 4004 team games were played on grass. We examined the 2000-2009 game-related injury data from those games as recorded by the injury surveillance system. The data included the injury diagnosis, the date of injury, and the surface at the time of injury. The injury data showed that 1528 knee sprains and 1503 ankle sprains occurred during those games. We calculated injury rates for knee sprains and ankle sprains-specifically, medial collateral ligament (MCL) sprains, anterior cruciate ligament (ACL) sprains, eversion ankle sprains, and inversion ankle sprains-using incidence density ratios (IDRs). We used a Poisson model and logistic regression odds ratios to validate the IDR analysis. A multivariate logistic regression model was used to adjust the odds ratio for weather conditions. The observed injury rate of knee sprains on FieldTurf was 22% (IDR = 1.22, 95% confidence interval [CI], 1.09-1.36) higher than on grass, and the injury rate of ankle sprains on FieldTurf was 22% (IDR = 1.22, 95% CI, 1.09-1.36) higher than on grass. These differences are statistically significant. Specifically, the observed injury rates of ACL sprains and eversion ankle sprains on FieldTurf surfaces were 67% (P < .001) and

  18. Whiplash injuries.

    PubMed

    Malanga, Gerard; Peter, Jason

    2005-10-01

    Whiplash injuries are very common and usually are associated with rear-end collisions. However, a whiplash injury can be caused by any event that results in hyperextension and flexion of the cervical spine. These injuries are of serious concern to all consumers due to escalating cost of diagnosis, treatment, insurance, and litigation. Most acute whiplash injury cases respond well to conservative treatments, which result in resolution of symptoms usually within weeks to a few months after the injury occurred. Chronic whiplash injuries often are harder to diagnose and treat and often result in poor outcomes. Current research shows that various structures in the cervical spine receive nociceptive innervation and potentially may be the cause of chronic pain symptoms. One potential pain generator showing promise is the facet or zygapophyseal joints. Various researchers have proven that these joints are injured during whiplash injuries and that diagnosis and temporary pain relief can be obtained with facet joint injections. The initial evaluation of any patient should follow an organized and stepwise approach, and more serious causes of neck pain must first be ruled out through the history, physical examination, and diagnostic testing. Treatment regimens should be evidence-based, focusing on treatments that have proven to be effective in treating acute and chronic whiplash injuries.

  19. Continental like crust beneath the Andaman Island through joint inversion of receiver function and surface wave from ambient seismic noise

    NASA Astrophysics Data System (ADS)

    Gupta, Sandeep; Borah, Kajaljyoti; Saha, Gokul

    2016-09-01

    We study shear wave velocity structure of the crust beneath the Andaman Island through joint inversion of the teleseismic receiver function and Rayleigh wave group velocity measurements from 10 broadband seismographs over the Island. The group velocities in the periods from 5 to 21 s are obtained using cross-correlation of six month's ambient seismic noise data recorded by these seismic stations. Joint inversion results show 2 to 6 km thick subsurface low shear velocity (Vs 1.3-2.5 km/s) layer followed by a 12-14 km thick layer of silicic material (average Vs 3.5 km/s). The lower crust is mapped as an 8-12 km thick mafic layer with Vs 4.0 km/s. Uppermost mantle shear wave velocity is 4.55 km/s. The near-surface low-velocity layer is interpreted as the Andaman flysch sediments. The crustal thickness beneath the Andaman Island varies from 24 km in the north to 32 km in the south. The shear wave velocity-depth results show that the crustal structure beneath the Andaman Island is akin to continental crust, possibly the Burma continental crust. The subducting Indian plate may lie down below this overriding plate.

  20. Microparticle enlargement and altered surface proteins after air decompression are associated with inflammatory vascular injuries

    PubMed Central

    Yang, Ming; Milovanova, Tatyana N.; Bogush, Marina; Uzun, Günalp; Bhopale, Veena M.

    2012-01-01

    Studies in a murine model have shown that decompression stress triggers a progressive elevation in the number of circulating annexin V-coated microparticles derived from leukocytes, erythrocytes, platelets, and endothelial cells. We noted that some particles appeared to be larger than anticipated, and size continued to increase for ≥24 h postdecompression. These observations led to the hypothesis that inert gas bubbles caused the enlargement and particle size could be reduced by hydrostatic pressure. After demonstrating pressure-induced particle size reduction, we hypothesized that annexin V-positive particle changes associated with decompression contributed to their proinflammatory potential. Intravenous injection of naive mice with particles isolated from decompressed mice, but not control mice, caused intravascular neutrophil activation; perivascular neutrophil sequestration and tissue injuries were documented as elevations of vascular permeability and activated caspase-3. These changes were not observed if mice were injected with particles that had been subjected to hydrostatic recompression or particles that had been emulsified by incubation with polyethylene glycol telomere B surfactant. Hydrostatic pressure and surfactant incubation also altered the pattern of proteins expressed on the surface of particles. We conclude that proinflammatory events and vascular damage are due to enlargement of annexin V-coated particles and/or changes in surface marker protein pattern associated with provocative decompression. Injection of annexin V-coated particles from decompressed mice will recapitulate the pathophysiological vascular changes observed following decompression stress. PMID:21960660

  1. The effects of powered ankle-foot orthoses on joint kinematics and muscle activation during walking in individuals with incomplete spinal cord injury

    PubMed Central

    Sawicki, Gregory S; Domingo, Antoinette; Ferris, Daniel P

    2006-01-01

    Background Powered lower limb orthoses could reduce therapist labor during gait rehabilitation after neurological injury. However, it is not clear how patients respond to powered assistance during stepping. Patients might allow the orthoses to drive the movement pattern and reduce their muscle activation. The goal of this study was to test the effects of robotic assistance in subjects with incomplete spinal cord injury using pneumatically powered ankle-foot orthoses. Methods Five individuals with chronic incomplete spinal cord injury (ASIA C-D) participated in the study. Each subject was fitted with bilateral ankle-foot orthoses equipped with artificial pneumatic muscles to power ankle plantar flexion. Subjects walked on a treadmill with partial bodyweight support at four speeds (0.36, 0.54, 0.72 and 0.89 m/s) under three conditions: without wearing orthoses, wearing orthoses unpowered (passively), and wearing orthoses activated under pushbutton control by a physical therapist. Subjects also attempted a fourth condition wearing orthoses activated under pushbutton control by them. We measured joint angles, electromyography, and orthoses torque assistance. Results A therapist quickly learned to activate the artificial pneumatic muscles using the pushbuttons with the appropriate amplitude and timing. The powered orthoses provided ~50% of peak ankle torque. Ankle angle at stance push-off increased when subjects walked with powered orthoses versus when they walked with passive-orthoses (ANOVA, p < 0.05). Ankle muscle activation amplitudes were similar for powered and passive-orthoses conditions except for the soleus (~13% lower for powered condition; p < 0.05). Two of the five subjects were able to control the orthoses themselves using the pushbuttons. The other three subjects found it too difficult to coordinate pushbutton timing. Orthoses assistance and maximum ankle angle at push-off were smaller when the subject controlled the orthoses compared to when the therapist

  2. Formation of phase-change and relief-change recording media by joint oxidative thermodecomposition of hexacarbonyls on the surface

    NASA Astrophysics Data System (ADS)

    Grinko, D. A.; Krujchin, A. A.

    1995-11-01

    In the paper we investigate the relationship of film composition prepared in conditions of joint oxidative hexacarbonyls thermodecomposition to the ratio of molybdenum and tungsten hexacarbonyls vapors pressure. The films are prepared in vacuum on the order of hundreds pascal in the flow reactor by controlling the deposition process. As an oxidizer we used air. The vapor pressure measured by means of thermoelectric converters using the technique to an accuracy of 5%. The film thickness was on the order of hundreds of nanometers. For substrate we used monocrystal silicon. The film composition was determined by layer-by-layer auger spectroscopy method. The investigations were pursued on the JSM-T-20 auger analyzer by internal standards method in conditions of continuous film surface etching in an argon ion beam.

  3. Synovial tissue morphology of the cricoarytenoid joint in the elderly: a histological comparison with the cricothyroid joint

    PubMed Central

    Katsumura, Sakura; Kitamura, Kei; Kasahara, Masaaki; Katori, Yukio; Abe, Shin-ichi

    2016-01-01

    We compared the age-related morphology of the cricothyroid (CT) joint with that of the cricoarytenoid (CA) joint using 18 specimens from elderly cadavers in terms of their elastic fiber contents as well as the cells composing the joint capsule and synovial tissues. In contrast to an almost flat-flat interface in the CT joint, the CA joint was similar to a saddle joint. The CA joint capsule was thin and contained few elastic fibers, and in contrast to the CT joint, external fibrous tissues were not exposed to the joint cavity, there being no injury to the CA joint capsule. The lateral and posterior aspects of the CA joint were covered by the lateral and posterior CA muscles, respectively, and the fascia of the latter muscle was sometimes thick with abundant elastic fibers. However, due to possible muscle degeneration, loose connective tissue was often interposed between the fascia and the capsule. The medial and anterior aspects of the CA joint faced loose tissue that was continuous with the laryngeal submucosal tissue. Therefore, in contrast to the CT joint, a definite supporting ligament was usually absent in the CA joint. Synovial folds were always seen in the CA joint, comprising a short triangular mass on the posterior side and long laminar folds on the anterior side. The synovial folds usually contained multiple capillaries and a few CD68-positive macrophages. High congruity of the CA joint surfaces as well as strong muscle support to the arytenoid cartilage appeared to provide the specific synovial morphology. PMID:27051568

  4. Adult hand injuries on artificial ski slopes.

    PubMed

    Keramidas, Evangelos; Miller, Gavin

    2005-10-01

    Artificial ski slope skiing is a popular sport in Great Britain with significant risk of injury. We reviewed 36 patients who had been treated for hand injuries excluding the wrist in our plastic surgery department over a 14-month period after skiing on an artificial ski slope. Specifically, they were 15 fractures of the digits, 3 dislocations of the finger joints, 7 ulnar collateral ligament injuries of the metacarpophalangeal joint of the thumb, and 11 bruises and abrasions. The mean age of the patients was 28 years, and there were 20 men and 16 women. It is concluded that the hardness of the surface of the artificial ski slopes could be responsible for the types of injuries.

  5. Effect of joint pathology, surface preparation and fixation methods on union frequency after first metatarsophalangeal joint arthrodesis: A systematic review of the English literature.

    PubMed

    Korim, Muhammad Tawfiq; Mahadevan, Devendra; Ghosh, Arijit; Mangwani, Jitendra

    2017-09-01

    The aim of this systematic review was to perform a qualitative synthesis of the current literature to determine the union frequencies for first metatarsophalangeal joint arthrodesis as well as the influence of pathology, joint preparation and fixation methods on union. MEDLINE and EMBASE were searched to identify relevant studies reporting on first metatarsophalangeal joint union frequencies. 26 studies with 2059 feet met our inclusion criteria. The mean age was 60 years (range 18-84) and the mean follow-up was 32.6 months (range 1.5-156). The union frequency was 93.5% (1923/2059). The union frequencies were significantly higher when low velocity joint preparation methods were used (P<0.0001, Chi Square 22.5) and the pathology was hallux rigidus (P=0.002, Chi square 9.3). There were similarly high union frequencies with crossed screws, locking plate and non-locking plates. High union frequency can be expected following first metatarsophalangeal arthrodesis, especially when low velocity joint preparation methods are used in patients with hallux rigidus. Copyright © 2016 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  6. Wiener filtering of surface EMG with a priori SNR estimation toward myoelectric control for neurological injury patients.

    PubMed

    Liu, Jie; Ying, Dongwen; Zhou, Ping

    2014-12-01

    Voluntary surface electromyogram (EMG) signals from neurological injury patients are often corrupted by involuntary background interference or spikes, imposing difficulties for myoelectric control. We present a novel framework to suppress involuntary background spikes during voluntary surface EMG recordings. The framework applies a Wiener filter to restore voluntary surface EMG signals based on tracking a priori signal to noise ratio (SNR) by using the decision-directed method. Semi-synthetic surface EMG signals contaminated by different levels of involuntary background spikes were constructed from a database of surface EMG recordings in a group of spinal cord injury subjects. After the processing, the onset detection of voluntary muscle activity was significantly improved against involuntary background spikes. The magnitude of voluntary surface EMG signals can also be reliably estimated for myoelectric control purpose. Compared with the previous sample entropy analysis for suppressing involuntary background spikes, the proposed framework is characterized by quick and simple implementation, making it more suitable for application in a myoelectric control system toward neurological injury rehabilitation.

  7. Joint Sensing/Sampling Optimization for Surface Drifting Mine Detection with High-Resolution Drift Model

    DTIC Science & Technology

    2012-09-01

    completeness and future flexibility. B. FURTHER RESEARCH To further the research presented in this paper , large timescale studies should be conducted in order... reviewing instruction, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of... research is to provide such a methodology by modeling idealized stationary sensors and surface drift for the Hampton Roads Inlet. 14

  8. The Interplay of Surface Mount Solder Joint Quality and Reliability of Low Volume SMAs

    NASA Technical Reports Server (NTRS)

    Ghaffarian, R.

    1997-01-01

    Spacecraft electronics including those used at the Jet Propulsion Laboratory (JPL), demand production of highly reliable assemblies. JPL has recently completed an extensive study, funded by NASA's code Q, of the interplay between manufacturing defects and reliability of ball grid array (BGA) and surface mount electronic components.

  9. Alteration of cartilage surface collagen fibers differs locally after immobilization of knee joints in rats.

    PubMed

    Nagai, Momoko; Aoyama, Tomoki; Ito, Akira; Tajino, Junichi; Iijima, Hirotaka; Yamaguchi, Shoki; Zhang, Xiangkai; Kuroki, Hiroshi

    2015-05-01

    The purpose of this study was to examine the ultrastructural changes of surface cartilage collagen fibers, which differ by region and the length of the experimental period in an immobilization model of rat. Male Wistar rats were randomly divided into histological or macroscopic and ultrastructural assessment groups. The left knees of all the animals were surgically immobilized by external fixation for 1, 2, 4, 8 or 16 weeks (n = 5/time point). Sagittal histological sections of the medial mid-condylar region of the knee were obtained and assessed in four specific regions (contact and peripheral regions of the femur and tibia) and two zones (superficial and deep). To semi-quantify the staining intensity of the collagen fibers in the cartilage, picrosirius red staining was used. The cartilage surface changes of all the assessed regions were investigated by scanning electron microscopy (SEM). From histological and SEM observations, the fibrillation and irregular changes of the cartilage surface were more severe in the peripheral region than in the contact region. Interestingly, at 16 weeks post-immobilization, we observed non-fibrous structures at both the contact and peripheral regions. The collagen fiber staining intensity decreased in the contact region compared with the peripheral region. In conclusion, the alteration of surface collagen fiber ultrastructure and collagen staining intensity differed by the specific cartilage regions after immobilization. These results demonstrate that the progressive degeneration of cartilage is region specific, and depends on the length of the immobilization period.

  10. Exposure to elevated sea-surface temperatures below the bleaching threshold impairs coral recovery and regeneration following injury.

    PubMed

    Bonesso, Joshua Louis; Leggat, William; Ainsworth, Tracy Danielle

    2017-01-01

    Elevated sea surface temperatures (SSTs) are linked to an increase in the frequency and severity of bleaching events due to temperatures exceeding corals' upper thermal limits. The temperatures at which a breakdown of the coral-Symbiodinium endosymbiosis (coral bleaching) occurs are referred to as the upper thermal limits for the coral species. This breakdown of the endosymbiosis results in a reduction of corals' nutritional uptake, growth, and tissue integrity. Periods of elevated sea surface temperature, thermal stress and coral bleaching are also linked to increased disease susceptibility and an increased frequency of storms which cause injury and physical damage to corals. Herein we aimed to determine the capacity of corals to regenerate and recover from injuries (removal of apical tips) sustained during periods of elevated sea surface temperatures which result in coral stress responses, but which do not result in coral bleaching (i.e., sub-bleaching thermal stress events). In this study, exposure of the species Acropora aspera to an elevated SST of 32 °C (2 °C below the bleaching threshold, 34 °C) was found to result in reduced fluorescence of green fluorescent protein (GFP), reduced skeletal calcification and a lack of branch regrowth at the site of injury, compared to corals maintained under ambient SST conditions (26 °C). Corals maintained under normal, ambient, sea surface temperatures expressed high GFP fluorescence at the injury site, underwent a rapid regeneration of the coral branch apical tip within 12 days of sustaining injury, and showed extensive regrowth of the coral skeleton. Taken together, our results have demonstrated that periods of sustained increased sea surface temperatures, below the corals' bleaching threshold but above long-term summertime averages, impair coral recovery from damage, regardless of the onset or occurrence of coral bleaching.

  11. Joint Prediction of Longitudinal Development of Cortical Surfaces and White Matter Fibers from Neonatal MRI.

    PubMed

    Rekik, Islem; Li, Gang; Yap, Pew-Thian; Chen, Geng; Lin, Weili; Shen, Dinggang

    2017-03-08

    The human brain can be modeled as multiple interrelated shapes (or a multishape), each for characterizing one aspect of the brain, such as the cortex and white matter pathways. Predicting the developing multishape is a very challenging task due to the contrasting nature of the developmental trajectories of the constituent shapes: smooth for the cortical surface and non-smooth for white matter tracts due to changes such as bifurcation. We recently addressed this problem and proposed an approach for predicting the multishape developmental spatiotemporal trajectories of infant brains based only on neonatal MRI data using a set of geometric, dynamic, and fiber-to-surface connectivity features. In this paper, we propose two key innovations to further improve the prediction of multishape evolution. First, for a more accurate cortical surface prediction, instead of simply relying on one neonatal atlas to guide the prediction of the multishape, we propose to use multiple neonatal atlases to build a spatially heterogeneous atlas using the multidirectional varifold representation. This individualizes the atlas by locally maximizing its similarity to the testing baseline cortical shape for each cortical region, thereby better representing the baseline testing cortical surface, which founds the multishape prediction process. Second, for temporally consistent fiber prediction, we propose to reliably estimate spatiotemporal connectivity features using low-rank tensor completion, thereby capturing the variability and richness of the temporal development of fibers. Experimental results confirm that the proposed variants significantly improve the prediction performance of our original multishape prediction framework for both cortical surfaces and fiber tracts shape at 3, 6, and 9 months of age. Our pioneering model will pave the way for learning how to predict the evolution of anatomical shapes with abnormal changes. Ultimately, devising accurate shape evolution prediction models

  12. Global-scale Joint Body and Surface Wave Tomography with Vertical Transverse Isotropy for Seismic Monitoring Applications

    NASA Astrophysics Data System (ADS)

    Simmons, Nathan; Myers, Steve

    2017-04-01

    We continue to develop more advanced models of Earth's global seismic structure with specific focus on improving predictive capabilities for future seismic events. Our most recent version of the model combines high-quality P and S wave body wave travel times and surface-wave group and phase velocities into a joint (simultaneous) inversion process to tomographically image Earth's crust and mantle. The new model adds anisotropy (known as vertical transverse isotropy) to the model, which is necessitated by the addition of surface waves to the tomographic data set. Like previous versions of the model the new model consists of 59 surfaces and 1.6 million model nodes from the surface to the core-mantle boundary, overlaying a 1-D outer and inner core model. The model architecture is aspherical and we directly incorporate Earth's expected hydrostatic shape (ellipticity and mantle stretching). We also explicitly honor surface undulations including the Moho, several internal crustal units, and the upper mantle transition zone undulations as predicated by previous studies. The explicit Earth model design allows for accurate travel time computation using our unique 3-D ray tracing algorithms, capable of 3-D ray tracing more than 20 distinct seismic phases including crustal, regional, teleseismic, and core phases. Thus, we can now incorporate certain secondary (and sometimes exotic) phases into source location determination and other analyses. New work on model uncertainty quantification assesses the error covariance of the model, which when completed will enable calculation of path-specific estimates of uncertainty for travel times computed using our previous model (LLNL-G3D-JPS) which is available to the monitoring and broader research community and we encourage external evaluation and validation. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  13. Precision holding prediction model for moving joint surfaces of large machine tool

    NASA Astrophysics Data System (ADS)

    Wang, Mulan; Chen, Xuanyu; Ding, Wenzheng; Xu, Kaiyun

    2017-01-01

    In large machine tool, the plastic guide rail is more and more widely used because of its good mechanical properties. Based on the actual operating conditions of the machine tool, this paper analyzes the precision holding performance of the main bearing surface of the large machine tool with plastic guide rail moving. The precision holding performance of the plastic sliding guide rail is studied in detail from several aspects, such as the lubrication condition, the operating parameters of the machine tool and the material properties. The precision holding model of the moving binding surface of the plastic coated guide rail is established. At the same time, the experimental research on the accuracy of the guide rail is carried out, which verifies the validity of the theoretical model.

  14. Acute high-grade acromioclavicular joint injuries treatment: Arthroscopic non-rigid coracoclavicular fixation provides better quality of life outcomes than hook plate ORIF.

    PubMed

    Natera-Cisneros, L; Sarasquete-Reiriz, J; Escolà-Benet, A; Rodriguez-Miralles, J

    2016-02-01

    Treatment of acute high-grade acromioclavicular joint (ACJ) injuries with metal hardware alters the biomechanics of the ACJ, implying a second surgery for hardware removal. The period during which the plate is present involves functional limitations, pain and a risk factor for the development of hardware-related-injuries. Arthroscopy-assisted procedures compared to open-metal hardware techniques offer: less morbidity, the possibility to treat associated lesions and no need for a second operation. The aim was to compare the Quality of life (QoL) of patients with acute high-grade ACJ injuries (Rockwood grade III-V), managed arthroscopically with a non-rigid coracoclavicular (CC) fixation versus the QoL of patients managed with a hook plate, 24 months or more after their shoulder injury. A retrospective revision of high-grade ACJ injuries managed in three institutions was performed. Patients treated by means of an arthroscopy-assisted CC fixation or by means of a hook plate were included. The inclusion period was between 2008 and 2012. The QoL was evaluated at the last follow-up visit by means of the SF36, the visual analog scale (VAS), the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, the Constant score and the global satisfaction (scale from 0 to 10). The presence of scapular dyskinesis and remaining vertical instability were evaluated. Comparison between groups was performed. Thirty-one patients were included: 20 arthroscopy-group (ARTH group: 3 Rockwood III, 3 IV and 14 V) and 11 hook plate-group (HOOK group: 5 Rockwood III and 6 V). The mean age was 36 [25-52] year-old for the ARTH group and 41 [19-55] for the HOOK group (P=0.185). The mean results of the questionnaires were: (1) physical SF36 score (ARTH group 58.24±2.16 and HOOK group 53.70±4.33, P<0.001); (2) mental SF36 score (ARTH group 56.15±2.21 and HOOK group 53.06±6.10, P=0.049); (3) VAS (ARTH group 0.40±0.50 and HOOK group 1.45±1.51, P=0.007); (4) DASH (ARTH group 2.98±2.03 and

  15. A sequential data assimilation approach for the joint reconstruction of mantle convection and surface tectonics

    NASA Astrophysics Data System (ADS)

    Bocher, M.; Coltice, N.; Fournier, A.; Tackley, P. J.

    2016-01-01

    With the progress of mantle convection modelling over the last decade, it now becomes possible to solve for the dynamics of the interior flow and the surface tectonics to first order. We show here that tectonic data (like surface kinematics and seafloor age distribution) and mantle convection models with plate-like behaviour can in principle be combined to reconstruct mantle convection. We present a sequential data assimilation method, based on suboptimal schemes derived from the Kalman filter, where surface velocities and seafloor age maps are not used as boundary conditions for the flow, but as data to assimilate. Two stages (a forecast followed by an analysis) are repeated sequentially to take into account data observed at different times. Whenever observations are available, an analysis infers the most probable state of the mantle at this time, considering a prior guess (supplied by the forecast) and the new observations at hand, using the classical best linear unbiased estimate. Between two observation times, the evolution of the mantle is governed by the forward model of mantle convection. This method is applied to synthetic 2-D spherical annulus mantle cases to evaluate its efficiency. We compare the reference evolutions to the estimations obtained by data assimilation. Two parameters control the behaviour of the scheme: the time between two analyses, and the amplitude of noise in the synthetic observations. Our technique proves to be efficient in retrieving temperature field evolutions provided the time between two analyses is ≲10 Myr. If the amplitude of the a priori error on the observations is large (30 per cent), our method provides a better estimate of surface tectonics than the observations, taking advantage of the information within the physics of convection.

  16. Joint Inversion of Phase and Amplitude Data of Surface Waves for North American Upper Mantle

    NASA Astrophysics Data System (ADS)

    Hamada, K.; Yoshizawa, K.

    2015-12-01

    For the reconstruction of the laterally heterogeneous upper-mantle structure using surface waves, we generally use phase delay information of seismograms, which represents the average phase velocity perturbation along a ray path, while the amplitude information has been rarely used in the velocity mapping. Amplitude anomalies of surface waves contain a variety of information such as anelastic attenuation, elastic focusing/defocusing, geometrical spreading, and receiver effects. The effects of elastic focusing/defocusing are dependent on the second derivative of phase velocity across the ray path, and thus, are sensitive to shorter-wavelength structure than the conventional phase data. Therefore, suitably-corrected amplitude data of surface waves can be useful for improving the lateral resolution of phase velocity models. In this study, we collect a large-number of inter-station phase velocity and amplitude ratio data for fundamental-mode surface waves with a non-linear waveform fitting between two stations of USArray. The measured inter-station phase velocity and amplitude ratios are then inverted simultaneously for phase velocity maps and local amplification factor at receiver locations in North America. The synthetic experiments suggest that, while the phase velocity maps derived from phase data only reflect large-scale tectonic features, those from phase and amplitude data tend to exhibit better recovery of the strength of velocity perturbations, which emphasizes local-scale tectonic features with larger lateral velocity gradients; e.g., slow anomalies in Snake River Plain and Rio Grande Rift, where significant local amplification due to elastic focusing are observed. Also, the spatial distribution of receiver amplification factor shows a clear correlation with the velocity structure. Our results indicate that inter-station amplitude-ratio data can be of help in reconstructing shorter-wavelength structures of the upper mantle.

  17. Consequences and Costs of Lower Extremity Injuries

    PubMed Central

    Dischinger, PC; Read, KM; Kufera, JA; Kerns, TJ; Burch, CA; Jawed, N; Ho, SM; Burgess, AR

    2004-01-01

    Lower extremity injuries resulting from motor vehicle crashes are common and have become relatively more important as more drivers with newer occupant restraints survive high-energy crashes. CIREN data provide a greater level of clinical detail based on coding guidelines from the Orthopedic Trauma Association. These detailed data, in conjunction with long-term follow-up data obtained from patient interviews, reveal that the most costly and disabling injuries are those involving articular (joint) surfaces, especially those of the ankle/foot. Patients with such injuries exhibit residual physical and psychosocial problems, even at one year post-trauma. PMID:15319134

  18. Curcumin improves neural function after spinal cord injury by the joint inhibition of the intracellular and extracellular components of glial scar.

    PubMed

    Yuan, Jichao; Zou, Mingming; Xiang, Xin; Zhu, Haitao; Chu, Weihua; Liu, Wei; Chen, Fei; Lin, Jiangkai

    2015-05-01

    Spinal cord injury (SCI) is characterized by a high rate of disability and imposes a heavy burden on society and patients. SCI can activate glial cells and lead to swelling, hyperplasty, and reactive gliosis, which can severely reduce the space for nerve growth. Glial cells can secrete a large amount of extracellular inhibitory components, thus altering the microenvironment of axon growth. Both these factors seriously impede nerve regeneration. In the present study, we investigate whether curcumin (cur), a phytochemical compound with potent anti-inflammatory effect, plays a role in the repair of SCI. We established a rat model of SCI and treated the animals with different concentrations of cur. Using behavioral assessment, immunohistochemistry, real-time polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay, we detected the intracellular and extracellular components of glial scar and related cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, nuclear factor (NF)-κb, transforming growth factor (TGF)-β1, TGF-β2, and sex determining region Y-box (SOX)-9. We found that cur inhibited the expression of proinflammatory cytokines, such as TNF-α, IL-1β, and NF-κb; reduced the expression of the intracellular components glial fibrillary acidic protein through anti-inflammation; and suppressed the reactive gliosis. Also, cur inhibited the generation of TGF-β1, TGF-β2, and SOX-9; decreased the deposition of chondroitin sulfate proteoglycan by inhibiting the transforming growth factors and transcription factor; and improved the microenvironment for nerve growth. Through the joint inhibition of the intracellular and extracellular components of glial scar, cur significantly reduced glial scar volume and improved the Basso, Beattie, and Bresnahan locomotor rating and axon growth. Our data support a role for curcumin in promoting neural function recovery after SCI by the joint inhibition of the intracellular and extracellular

  19. Effects of mobility/immobility of surface modification by 2-methacryloyloxyethyl phosphorylcholine polymer on the durability of polyethylene for artificial joints.

    PubMed

    Kyomoto, Masayuki; Moro, Toru; Miyaji, Fumiaki; Hashimoto, Masami; Kawaguchi, Hiroshi; Takatori, Yoshio; Nakamura, Kozo; Ishihara, Kazuhiko

    2009-08-01

    Surface modification is important for the improvement in medical device materials. 2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers have attracted considerable attention as surface modifiable polymers for several medical devices. In this study, we hypothesize that the structure of the surface modification layers might affect the long-term stability, hydration kinetics, wear resistance, and so forth, of medical devices such as artificial joints, and the poly(MPC) (PMPC) grafted surface might assure the long-term performance of such devices. Therefore, we investigate the surface properties of various surface modifications by using dip coatings of MPC-co-n-butyl methacrylate (PMB30) and MPC-co-3-methacryloxypropyl trimethoxysilane (PMSi90) polymers, or photoinduced radical grafting of PMPC and also the effects of the surface properties on the durability of cross-linked polyethylene (CLPE) for artificial joints. The PMPC-grafted CLPE has an extremely low and stable coefficient of dynamic friction and volumetric wear as compared to the untreated CLPE, PMB30-coated CLPE, and PMSi90-coated CLPE. It is concluded that the photoinduced radical graft polymerization of MPC is the best method to retain the benefits of the MPC polymer used in artificial joints under variable and multidirectional loads for long periods with strong bonding between the MPC polymer and the CLPE surface, and also to retain the high mobility of the MPC polymer.

  20. Electrical properties of rat muscle after sciatic nerve injury: Impact on surface impedance measurements assessed via finite element analysis

    NASA Astrophysics Data System (ADS)

    Ahad, M. A.; Rutkove, S. B.

    2010-04-01

    Tetrapolar surface electrical impedance methods are sensitive to changes in muscle status and can therefore provide a means for studying neuromuscular disease noninvasively. In order to better understand the relationship between surface impedance measurements and the actual muscle electrical properties, we performed measurements on 20 adult Wistar rats, 8 of which underwent sciatic nerve crush. Surface impedance measurements were performed on the left hind limb both before injury and out to 2 weeks after injury. In addition, both normal and sciatic crush animals were sacrificed and the dielectric properties of the extracted gastrocnemius muscle measured. We found that 50 kHz conductivities were greater in the animals that underwent crush than in the animals that did not. The permittivities in both directions, however, showed non-significant differences. In order to analyze the effect of these changes as well as the accompanying reduction in muscle volume, a finite element model of the hind limb was developed based on computerized tomographic imaging. The model successfully predicted the surface impedance values in the animals after crush injury and, by its inverse application, may be used to help determine the underlying electrical properties of muscle in various neuromuscular diseases based on surface impedance data.

  1. Effect of the rotational speed of on the surface quality of 6061 Al-alloy welded joint using friction stir welding

    NASA Astrophysics Data System (ADS)

    Feng, T. T.; Zhang, X. H.; Fan, G. J.; Xu, L. F.

    2017-06-01

    The rotational speed of the stir-welding head is an important technological parameter in friction stir welding (FSW) process. For investigating the effect of the rotational speed of the stir-welding head on the surface quality of the welded joint, in this study, the weld tests were conducted under different rotational speeds (in which the welding speed was fixed), and then the effects were analyzed using the heat-fluid analysis model established. The test results revealed that cracks or grooves could be observed on the welded joint at small rotational speeds; with the increase of rotational speed, the weld surface became bright and clean; as the rotational speed further increased, the surface of the welded joint may be over burnt. Through analysis, it can be observed that appropriate increasing the rotational speed of the stir-welding joint increased the heat input in welding; meanwhile, fewer materials participated in the formation of weld, the material’s flowability was improved, and the resistance that impeded the advance of the stir-welding needle was reduced, thereby improving the quality of the welded joint.

  2. Drop Reliability of Epoxy-contained Sn-58 wt.%Bi Solder Joint with ENIG and ENEPIG Surface Finish Under Temperature and Humidity Test

    NASA Astrophysics Data System (ADS)

    Myung, Woo-Ram; Kim, Yongil; Kim, Kyung-Yeol; Jung, Seung-Boo

    2016-07-01

    The influence of two kinds of surface finish, namely electroless nickel immersion gold (ENIG) and electroless nickel electroless palladium immersion gold (ENEPIG), on the interfacial reactions and drop reliability of epoxy-enhanced Sn-58 wt.%Bi solder has been investigated after temperature-humidity storage tests. The chemical composition and morphology of intermetallic compounds (IMCs) were characterized by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and electron probe microanalysis. Also, the mechanical reliability of solder joints was evaluated using board-level drop tests. The Sn-Bi epoxy solder/ENEPIG joint exhibited higher IMC growth rate than the Sn-Bi epoxy solder/ENIG joint. After 500 h at 85°C/85% RH storage condition, new IMCs were formed on the Ni3Sn4 layer in samples with both surface finishes. The results of board-level drop tests showed that the number of drops was higher for the ENIG than the ENEPIG surface finish. Solder joint fracture occurred along the interface between the solder and IMC layer for the ENIG surface finish. However, with the ENEPIG surface finish, the crack propagated between the IMCs.

  3. Effects of Microstructure and Loading on Fracture of Sn-3.8Ag-0.7Cu Joints on Cu Substrates with ENIG Surface Finish

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Kumar, P.; Dutta, I.; Sidhu, R.; Renavikar, M.; Mahajan, R.

    2014-12-01

    When dropped, electronic packages often undergo failure by propagation of an interfacial crack in solder joints under a combination of tensile and shear loading. Hence, it is crucial to understand and predict the fracture behavior of solder joints under mixed-mode high-rate loading conditions. In this work, the effects of the loading conditions (strain rate and loading angle) and microstructure [interfacial intermetallic compound (IMC) morphology and solder yield strength] on the mixed-mode fracture toughness of Sn-3.8 wt.%Ag-0.7 wt.%Cu solder joints sandwiched between two Cu substrates with electroless nickel immersion gold (ENIG) metallization have been studied, and compared with the fracture behavior of joints attached to bare Cu. Irrespective of the surface finish, the fracture toughness of the solder joints decreased monotonically with strain rate and mode-mixity, both resulting in increased fracture proportion through the interfacial IMC layer. Furthermore, the proportion of crack propagation through the interfacial IMC layer increased with increase in the thickness and the roughness of the interfacial IMC layer and the yield strength of the solder, resulting in a decrease in the fracture toughness of the joint. However, under most conditions, solder joints with ENIG finish showed higher resistance to fracture than joints attached directly to Cu substrates without ENIG metallization. Based on the experimental observations, a fracture mechanism map is constructed correlating the yield strength of the solder, the morphology and thickness of the interfacial IMC, and the fracture mechanisms as well as the fracture toughness values for different solder joints under mode I loading.

  4. Contact areas of the tibiotalar joint.

    PubMed

    Windisch, Gunther; Odehnal, Boris; Reimann, Reinhold; Anderhuber, Friedrich; Stachel, Hellmuth

    2007-11-01

    The contact areas between the articular surfaces of the talus and tibia are essential for understanding the mobility of the ankle joint. The purpose of our study was to reveal the contact area among the superior articular surface of the trochlea tali (target surface T) and the inferior articular surface of the tibia (query surface Q) under non-weight-bearing conditions in plantar flexion and dorsiflexion. Twenty cadaveric foot specimens were dissected and scanned by a three-dimensional (3D) laser scanner to obtain data point sets. These point sets were triangulated and a registration procedure performed to avoid any intersection of the two joint surfaces. For all points of the query surface Q, the closest distance to T was measured. In 11 of the 20 ankle joints, the contact area was larger in plantar flexion, in 5 it was nearly of equal size, and in 4 the two surfaces were found in a better congruence in dorsiflexion. The two articular surfaces can be in point or line contact and cause different motions while T is gliding on Q, so the original geometry of ligaments must be carefully reconstructed after injury or during total ankle replacement.

  5. Jointly Retrieving Surface Soil Moisture from Active and Passive Microwave Observations Using Cubist Data-Mining

    NASA Astrophysics Data System (ADS)

    Zhan, X.; Houser, P. R.

    2004-12-01

    With the successful launches of NASA's Earth Observing Satellites (e.g. Terra & Aqua) and several environmental satellites (e.g. NPOESS, NPP, SMOS and HYDROS) being planned to launch in the near future, huge amounts of satellite remote sensing data are being collected every day. Maximizing the use of this wealth of data sets is a pressing issue for the Earth system science community. Data mining is extracts patterns from large system data sets. These patterns provide insight into system characteristics that enable outcome prediction for future situations that aids decision-making. The Cubist data-mining algorithm is a powerful tool for generating rule-based models that balance the need for accurate prediction against the requirements of intelligibility. Cubist models generally give better results than those produced by simple techniques such as multivariate linear regression, and are generally easier to understand than neural networks. The NASA's Hydrosphere States (HYDROS) mission, an Earth System Science Pathfinder, will use both L-band microwave coarse resolution radiometer and fine-resolution radar to make the first space borne observations of global soil water availability. These new observations will enable new scientific investigations of atmospheric predictability and global change processes. To assess the potential accuracies of retrieving land surface soil moisture from the radiometer and radar observations, the HYDROS science team has created an Observing System Simulation Experiment (OSSE) that includes a complete land surface geophysical properties data set (soil moisture, surface temperature, vegetation temperature, etc), the associated atmospheric variables, and the simulated HYDROS radar and radiometer observations for the Red-Arkansas river basin. We have applied the Cubist data-mining algorithm to this OSSE data set to evaluate its soil moisture retrieval skill using the active and passive microwave observations simultaneously. The resulting

  6. One Hundred Ninety-five Cases of High-voltage Electric Injury

    DTIC Science & Technology

    2005-08-01

    tissue injury (laceration, contusion, hematoma ): 14 Lung injury (pneumothorax, contusion): 9 Brain/head injury ( subdural hematoma , intraparenchymal...corneal foreign body): 6 Nonfracture orthopedic injury (sprain, open joint): 3 Renal injury ( hematoma , contusion): 2 Intra-abdominal injury (spleen

  7. The Crust and Upper Mantle Structure of the Iranian Plateau from Joint Waveform Tomography Imaging of Body and Surface Waves

    NASA Astrophysics Data System (ADS)

    Roecker, S. W.; Priestley, K. F.; Tatar, M.

    2014-12-01

    The Iranian Plateau forms a broad zone of deformation between the colliding Arabian and Eurasian plates. The convergence is accommodated in the Zagros Mountains of SW Iran, the Alborz Mountains of northern Iran, and the Kopeh Dagh Mountains of NE Iran. These deforming belts are separated by relatively aseismic depressions such as the Lut Block. It has been suggested that the Arabia-Eurasia collision is similar to the Indo-Eurasia collision but at a early point of development and therefore, it may provide clues to our understanding of the earlier stages of the continent-continent collision process. We present results of the analysis of seismic data collected along two NE-SW trending transects across the Iranian Plateau. The first profile extends from near Bushere on the Persian Gulf coast to near to the Iran-Turkmenistan border north of Mashad, and consists of seismic recordings along the SW portion of the line in 2000-2001 and recording along the NE portion of the line in 2003 and 2006-2008. The second profile extends from near the Iran-Iraq border near the Dezfel embayment to the south Caspian Sea coast north of Tehran. We apply the combined 2.5D finite element waveform tomography algorithm of Baker and Roecker [2014] to jointly invert teleseismic body and surface waves to determine the elastic wavespeed structures of these areas. The joint inversion of these different types of waves affords similar types of advantages that are common to combined surface wave dispersion/receiver function inversions in compensating for intrinsic weaknesses in horizontal and vertical resolution capabilities. We compare results recovered from a finite difference approach to document the effects of various assumptions related to their application, such as the inclusion of topography, on the models recovered. We also apply several different inverse methods, starting with simple gradient techniques to the more sophisticated pseudo-Hessian or L-BFGS approach, and find that the latter are

  8. Acute high-grade acromioclavicular joint injuries: quality of life comparison between patients managed operatively with a hook plate versus patients managed non-operatively.

    PubMed

    Natera Cisneros, Luis Gerardo; Sarasquete Reiriz, Juan

    2017-04-01

    Surgical indication for acromioclavicular joint (ACJ) injuries still represents a reason for shoulder and trauma debate. In high-grade injuries, surgery is advocated because some of the non-operatively managed patients may have persistent shoulder pain that could make them unable to return to their previous activity. It has been shown that many of the patients with high-grade ACJ injuries that are managed non-operatively involve the development of scapular dyskinesis, situation that may result in loss of strength and weakness. On the other side, it has been widely reported that the period while the hook plate is present involves functional limitations and pain. The purpose of this study was to compare the quality of life (QoL) of patients with acute high-grade ACJ injuries (Rockwood grade III-V), managed operatively with a hook plate versus the QoL of patients managed non-operatively, 24 months or more after shoulder injury. Patients with acute high-grade ACJ injuries managed operatively (hook plate) or non-operatively, between 2008 and 2012 were included. The QoL was evaluated by means of the Health Survey questionnaire (SF36), the Visual Analogue Scale (VAS) for pain, the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, the Constant score and the Global Satisfaction (scale from 0 to 10) assessed at the last follow-up visit. The presence of scapular dyskinesis was assessed. Comparison between groups was made. Thirty-two patients were included: 11 hook plate-group (PLATE group) (5 Rockwood III and 6 V) and 21 conservative-group (CONS group) (4 Rockwood III and 17 V). The mean age was 41 [19-55] years old for the PLATE group and 38 [19-55] for the CONS group (p = 0.513). The mean follow-up was 32.50 ± 11.64 months for the PLATE group and 34.77 ± 21.98 months for the CONS group (p = 0.762). The mean results of the questionnaires assessed at the last follow-up visit were: (1) physical SF36 score (PLATE group 53.70 ± 4.33 and CONS group

  9. Heat-resistant organic molecular layer as a joint interface for metal reduction on plastics surfaces

    NASA Astrophysics Data System (ADS)

    Sang, Jing; Aisawa, Sumio; Hirahara, Hidetoshi; Kudo, Takahiro; Mori, Kunio

    2016-04-01

    Heat-resistant organic molecular layers have been fabricated by triazine-based silane coupling agent for metal reduction on plastic surfaces using adsorption method. These molecular layers were used as an interfacial layer between polyamide (PA6) and metal solution to reduce Ag+ ion to Ag0. The interfacial behaviors of triazine molecular layer at the interfaces between PA6 and Ag solution were investigated using quartz crystal microbalance (QCM). The kinetics of molecular adsorption on PA6 was investigated by using triazine-based silane coupling agent solutions at different pH and concentration. X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), and local nano thermal analysis were employed to characterize the surfaces and interfaces. The nano thermal analysis results show that molecular layers of triazine-based silane coupling agent greatly improved heat resistance of PA6 resin from 170 °C up to 230 °C. This research developed an in-depth insight for molecular behaviors of triazine-based silane coupling agent at the PA6 and Ag solution interfaces and should be of significant value for interfacial research between plastics and metal solution in plating industry.

  10. Crustal Structure in Southern Korea From Joint Analysis of Teleseismic Receiver Functions and Surface Wave Dispersion

    NASA Astrophysics Data System (ADS)

    Chang, S.; Baag, C.

    2004-12-01

    We estimated crustal structures at eighteen broadband stations in southern Korea by combining receiver functions and surface wave dispersion with the genetic algorithm (GA). The trend of the Moho depths estimated from the GA inversion generally coincides with the topography of the surface, ranging from 26 km to 36 km in inland. However, the Moho depth distribution does not agree with the topography in the region around the Chugaryeong Fault located approximately in NNE-SSW direction in the central area of the Korean peninsula. The shallow Moho depth under this region may be related to magmatic rift and consequential crustal thinning processes along the fault caused by an extensional tectonic movement. Another discrepancy is found in the Gyeongsang Basin, which was formed by the sedimentary deposits accumulated during Cretaceous extension caused by retroarc environment. The thick crust may be caused by both the maturity of basin and underplating of magma materials after the closure of the basin. The average crustal velocity is variable from 6.02 km/sec to 6.51 km/sec over southern Korea. This indicates that crustal structures in southern Korea involve diverse velocity profiles, changing rapidly with distance. It is also a remarkable phenomenon that an obvious discontinuity of the velocity is observed at 8-10 km depths under several stations.

  11. Joint replacement components made of hot-forged and surface-treated Ti-6Al-7Nb alloy.

    PubMed

    Semlitsch, M F; Weber, H; Streicher, R M; Schön, R

    1992-01-01

    We have developed a titanium-aluminium alloy with the inert alloying element niobium. The optimal composition was found to be Ti-6Al-7Nb (Protasul-100). This custom-made alloy designed for implants shows the same alpha/beta structure as Ti-6Al-4V and exhibits equally good mechanical properties. The corrosion resistance of Ti-6Al-7Nb in sodium chloride solution is equivalent to that of pure titanium and Ti-6Al-4V. This is due to a very dense and stable passive layer. Highly stressed anchorage stems of different hip prosthesis designs have been made from hot-forged Ti-6Al-7Nb. The polished surfaces of hip, knee and wrist joints made of Ti-6Al-7Nb and articulating against polyethylene are surface-treated by means of a very hard and 3-5 microns thick titanium nitride coating (Tribosul-TiN) or by oxygen diffusion hardening (Tribosul-ODH) to a depth of 30 microns.

  12. Joint swelling

    MedlinePlus

    Swelling of a joint ... Joint swelling may occur along with joint pain . The swelling may cause the joint to appear larger or abnormally shaped. Joint swelling can cause pain or stiffness. After an ...

  13. Shear velocity model for the Kyrgyz Tien Shan from joint inversion of receiver function and surface wave data

    NASA Astrophysics Data System (ADS)

    Gilligan, Amy; Roecker, Steven W.; Priestley, Keith F.; Nunn, Ceri

    2014-10-01

    The Tien Shan is the largest active intracontinental orogenic belt on Earth. To better understand the processes causing mountains to form at great distances from a plate boundary, we analyse passive source seismic data collected on 40 broad-band stations of the MANAS project (2005-2007) and 12 stations of the permanent KRNET seismic network to determine variations in crustal thickness and shear wave speed across the range. We jointly invert P- and S-wave receiver functions with surface wave observations from both earthquakes and ambient noise to reduce the ambiguity inherent in the images obtained from the techniques applied individually. Inclusion of ambient noise data improves constraints on the upper crust by allowing dispersion measurements to be made at shorter periods. Joint inversion can also reduce the ambiguity in interpretation by revealing the extent to which various features in the receiver functions are amplified or eliminated by interference from multiples. The resulting wave speed model shows a variation in crustal thickness across the range. We find that crustal velocities extend to ˜75 km beneath the Kokshaal Range, which we attribute to underthrusting of the Tarim Basin beneath the southern Tien Shan. This result supports the plate model of intracontinental convergence. Crustal thickness elsewhere beneath the range is about 50 km, including beneath the Naryn Valley in the central Tien Shan where previous studies reported a shallow Moho. This difference apparently is the result of wave speed variations in the upper crust that were not previously taken into account. Finally, a high velocity lid appears in the upper mantle of the Central and Northern part of the Tien Shan, which we interpret as a remnant of material that may have delaminated elsewhere under the range.

  14. Joint State and Parameter Estimation for Two Land Surface Models Using the Ensemble Kalman Filter and Particle Filter

    NASA Astrophysics Data System (ADS)

    Zhang, Hongjuan; Hendricks-Franssen, Harrie-Jan; Han, Xujun; Vrugt, Jasper A.; Vereecken, Harry

    2016-04-01

    Land surface models (LSMs) resolve the water and energy balance with different parameters and state variables. Many of the parameters of these models cannot be measured directly in the field, and require calibration against flux and soil moisture data. Two LSMs are used in our work: Variable Infiltration Capacity Hydrologic Model (VIC) and the Community Land Model (CLM). Temporal variations in soil moisture content at 5, 20 and 50 cm depth in the Rollesbroich experimental watershed in Germany are simulated in both LSMs. Data assimilation (DA) provides a good way to jointly estimate soil moisture content and soil properties of the resolved soil domain. Four DA methods combined with the two LSMs are used in our work: the Ensemble Kalman Filter (EnKF) using state augmentation or dual estimation, the Residual Resampling Particle Filter (RRPF) and Markov chain Monte Carlo Particle Filter (MCMCPF). These four DA methods are tuned and calibrated for a five month period, and subsequently evaluated for another five month period. Performances of the two LSMs and the four DA methods are compared. Our results show that all DA methods improve the estimation of soil moisture content of the VIC and CLM models, especially if the soil hydraulic properties (VIC), the maximum baseflow velocity (VIC) and/or soil texture (CLM) are jointly estimated with soil moisture content. The augmentation and dual estimation methods performed slightly better than RRPF and MCMCPF in the evaluation period. The differences in simulated soil moisture content between CLM and VIC were larger than variations among the DA methods. The CLM performed better than the VIC model. The strong underestimation of soil moisture content in the third layer of the VIC model is likely related to an inadequate parameterization of groundwater drainage.

  15. Effect of Toll-Like Receptor 4 on Synovial Injury of Temporomandibular Joint in Rats Caused by Occlusal Interference

    PubMed Central

    Kong, Jingjing; Yang, Yingying; Sun, Shuzhen; Xie, Jianli; Lin, Xuefen; Ji, Ping

    2016-01-01

    Synovitis is an important disease that causes intractable pain in TMJ. Some investigations suggested that the increasing expression of IL-1β secreted by synovial lining cells plays an important role in synovial inflammation and cartilage destruction in TMJ. In our previous research, the results demonstrated that TLR4 is involved in the expression of IL-1β in SFs from TMJ with lipopolysaccharide stimulation. However, the inflammatory response that occurred in synovial membrane is not caused by bacterial infection. In the current study, we investigated whether or not TLR4 participates in the inflammatory responses and the expression of IL-1β in synovial membrane of rats induced by occlusal interference. The results showed that obvious inflammation changes were observed in the synovial membranes and the expression of TLR4 and IL-1β was increased at both mRNA and protein levels in the occlusal interference rats. In addition, the inflammation reactions and the increased expression of IL-1β could be restrained by treatment with TAK-242, a blocker of TLR4 signaling. The results prompted us that the activation of TLR4 may be involved in the inflammatory reactions and increased expression of IL-1β in patients with synovitis and participate in the mechanisms of the initiation and development of synovial injury by regulating the expression of inflammatory mediators like IL-1β in synovial membranes. PMID:27413256

  16. The Sauvé-Kapandji procedure for chronic dislocation of the distal radio-ulnar joint with destruction of the articular surface.

    PubMed

    Nakamura, R; Tsunoda, K; Watanabe, K; Horii, E; Miura, T

    1992-04-01

    The Sauvé-Kapandji procedure has been performed in 15 non-rheumatoid patients with chronic distal radio-ulnar joint dislocation accompanied by joint damage or deformity. The clinical results were favourable; wrist pain improved in all patients, wrist flexion-extension was increased by more than 10 degrees in nine patients, grip strength of at least 80% of the contralateral wrist was achieved in 11 patients, and forearm rotation was more than 150 degrees in 12 patients. However, X-ray examination revealed an unstable proximal ulnar stump and radio-ulnar convergence in all patients similar to that associated with the Darrach procedure. Although the Sauvé-Kapandji procedure can preserve ulnar support of the wrist and is believed to yield more satisfactory results than the Darrach procedure, its extensive use is not recommended for non-rheumatoid distal radio-ulnar joint disorders, but it is recommended for chronic distal radio-ulnar joint dislocation with articular injury or deformity.

  17. Thermal inactivation and sublethal injury kinetics of Salmonella enterica and Listeria monocytogenes in broth versus agar surface.

    PubMed

    Wang, Xiang; Devlieghere, Frank; Geeraerd, Annemie; Uyttendaele, Mieke

    2017-02-21

    The objective of the present study was to compare the thermal inactivation and sublethal injury kinetics of Salmonella enterica and Listeria monocytogenes in broth (suspended cells) and on solid surface (agar-seeded cells). A 3-strain cocktail of S. enterica or L. monocytogenes inoculated in broth or on agar was subjected to heating in a water bath at various set temperatures (55.0, 57.5 and 60.0°C for S. enterica and 60.0, 62.5 and 65°C for L. monocytogenes). The occurrence of sublethally injured cells was determined by comparing enumerations on nonselective (TSAYE) and selective (XLD or ALOA) media. Results showed that the inactivation curves obtained from selective media were log-linear, and significant shoulders (p<0.05) were observed on some of the inactivation curves from TSAYE media. The D-values derived from the total population were higher than those from the uninjured cells. Generally, cells on agar surface exhibited higher heat resistance than those in broth. For S. enterica, cell injury increased with the exposure time, no difference was observed when treated at temperatures from 55.0 to 60.0°C, while for L. monocytogenes, cell injury increased significantly with heating time and treatment temperature (from 60.0 to 65°C). Moreover, the degree of sublethal injury affected by thermal treatment in broth or on agar surface depended upon the target microorganism. Higher proportions of injured S. enterica cells were observed for treatment in broth than on agar surface, while the opposite was found for L. monocytogenes. The provided information may be used to assess the efficacy of thermal treatment processes on surfaces for inactivation of S. enterica and L. monocytogenes, and it provides insight into the sublethally injured survival state of S. enterica and L. monocytogenes treated in liquid or on solid food.

  18. Synergistic estimation of surface parameters from jointly using optical and microwave observations in EOLDAS

    NASA Astrophysics Data System (ADS)

    Timmermans, Joris; Gomez-Dans, Jose; Lewis, Philip; Loew, Alexander; Schlenz, Florian

    2017-04-01

    The large amount of remote sensing data nowadays available provides a huge potential for monitoring crop development, drought conditions and water efficiency. This potential however not been realized yet because algorithms for land surface parameter retrieval mostly use data from only a single sensor. Consequently products that combine different low-level observations from different sensors are hard to find. The lack of synergistic retrieval is caused because it is easier to focus on single sensor types/footprints and temporal observation times, than to find a way to compensate for differences. Different sensor types (microwave/optical) require different radiative transfer (RT) models and also require consistency between the models to have any impact on the retrieval of soil moisture by a microwave instrument. Varying spatial footprints require first proper collocation of the data before one can scale between different resolutions. Considering these problems, merging optical and microwave observations have not been performed yet. The goal of this research was to investigate the potential of integrating optical and microwave RT models within the Earth Observation Land Data Assimilation System (EOLDAS) synergistically to derive biophysical parameters. This system uses a Bayesian data assimilation approach together with observation operators such as the PROSAIL model to estimate land surface parameters. For the purpose of enabling the system to integrate passive microwave radiation (from an ELBARRA II passive microwave radiometer), the Community Microwave Emission Model (CMEM) RT-model, was integrated within the EOLDAS system. In order to quantify the potential, a variety of land surface parameters was chosen to be retrieved from the system, in particular variables that a) impact only optical RT (such as leaf water content and leaf dry matter), b) only impact the microwave RT (such as soil moisture and soil temperature), and c) Leaf Area Index (LAI) that impacts both

  19. The Crust and Upper Mantle Structure of Northeastern Iran from Joint Waveform Tomography Imaging of Body and Surface Waves

    NASA Astrophysics Data System (ADS)

    Baker, B.; Roecker, S. W.; Priestley, K. F.; Tatar, M.

    2012-12-01

    The deformation resulting from the Arabian-Eurasian collision at the longitude of Iran is concentrated in the Zagros, Alborz and Kopeh Dagh Mountains. The Zagros and Alborz Mountains have been the focus of a number of studies but little is known about the structure of NE Iran and the Kopeh Dagh. The Kopeh Dagh form a linear intracontinental fold-and-thrust belt trending NW-SE between the stable Turkmenistan platform and Central Iran, and mark the northern limit to deformation in NE Iran. To the south of the Kopeh Dagh lie a series of elongated mountain ranges: the Binalud, which is a structural and geological eastward continuation of the Alborz, the Siah Kuh near Sabzevar and the Kuh-e-Sorkh near Kashmar. Between August 2006 and February 2008 we operated 17 broadband seismographs along a profile from Sarakhs, near the northeastern political border of Iran with Turkmenistan, across the Kopeh Dagh Mountains, to Yazd in Central Iran. We apply a combination of the teleseismic body wave waveform tomography technique of Roecker et al (2010) with an extension of this technique to surface waves (Roecker et al, 2011) to analyze this data to determine the elastic wavespeed structure of this area. The joint inversion of these different types of waves affords similar types of advantages that are common to combined surface wave dispersion/receiver function inversions in compensating for intrinsic weaknesses in horizontal and vertical resolution capabilities. We compare results recovered from a several different inverse methods, starting with simple gradient techniques to the more sophisticated pseudo-Hessian or L-BFGS approach, and find that the latter are generally more robust. Modelling of receiver functions and surface wave dispersion prior to the analysis is shown to be an efficacious way to generate starting models for this analysis.

  20. Impact of walking surface on the range of motion of equine distal limb joints for rehabilitation purposes.

    PubMed

    Mendez-Angulo, Jose L; Firshman, Anna M; Groschen, Donna M; Kieffer, Philip J; Trumble, Troy N

    2014-03-01

    The aim of this study was to evaluate the effect of three footing surfaces on the flexion/extension, and range of motion (ROM) of the carpus, tarsus and fetlocks in the horse. The percentage of stride spent in the stance phase of sound horses at the walk was also measured. Nine sound horses were walked on hard ground (HD), soft ground (SF) and a land treadmill (LT), and five complete gait cycles were recorded by a digital video camera. Retro-reflective markers were placed on the skin at four anatomical locations on the left fore and hind limbs, and data were analyzed using two-dimensional (2D) motion-analysis software. Maximal flexion/extension angles and range of motion were calculated for each joint, and the percentage of the stride spent in stance phase was determined for each stride. Maximal flexion of the tarsus and hind fetlock was greater on LT and SF compared to HD, while maximal flexion of the carpus was greater on LT compared to HD and SF. Maximal extension of the carpus was greater on HD compared to SF and LT, maximal extension of the tarsus was greater on HD and SF compared to LT, and maximal extension of the forelimb and hind limb fetlocks was greater on LT compared to HD and SF. The greatest overall ROM of the carpus and fetlocks was achieved on LT, while the greatest overall ROM of the tarsus was achieved on SF. The stance percentage of the stride for the hind limb was significantly different between all surfaces. In conclusion, walking surface influences flexion/extension of the carpus, tarsus and fetlocks in healthy horses, which should be considered when walking equine rehabilitation cases. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Sacroiliac injuries in horses.

    PubMed

    Lorenz, Jennifer; Brounts, Sabrina H

    2012-11-01

    This article reviews the pathology, diagnosis, and treatment of sacroiliac joint injuries. These injuries can be acute or chronic and can involve soft tissue structures surrounding the joint or the bony structures of the joint. The several diagnostic modalities for sacroiliac injuries vary in usefulness and accessibility. Treatment of sacroiliac problems is usually supportive and nonspecific and includes the use of antiinflammatory medications and an appropriate exercise regimen. The prognosis depends on the cause, but severe injuries can limit a horse's future athletic activity.

  2. Seismic Tomography of the Continental United States from a Joint Inversion of Surface Waves and Body Waves

    NASA Astrophysics Data System (ADS)

    Golos, E. M.; Yao, H.; Zhang, H.; Fang, H.; Burdick, S.; Schaeffer, A. J.; Vernon, F.; Lebedev, S.; van der Hilst, R. D.

    2015-12-01

    We present a model of seismic velocity anomalies for the entire continental United States—coast to coast, surface to lower mantle—using a joint body wave-surface wave inversion. This technique (Zhang et al., 2014), performed on a global adaptively-spaced grid, exploits the good vertical resolution at shallow depths of surface wave data, and the sampling of the deep mantle by teleseismic body (P and S) waves. The resultant model has better resolution at all depths than either method alone, enabling evaluation of interactions between lithospheric and mantle processes. We utilize the depth-dependence of surface wave sensitivity kernels to express surface wave phase velocity data directly in terms of spatial velocity structure (Fang et al., 2015). The data used are Rayleigh wave phase velocities from earthquakes and ambient noise (Schaeffer and Lebedev, 2013; Ekström, 2014) and S phase travel times from USArray, measured at the Array National Facility (ANF). We include a suite of synthetic tests to verify the performance of the inversion and compare it to results from traditional tomographic methods. We also use P arrivals and the influence of Vp on Rayleigh wave propagation speed to generate a preliminary model of Vp variations, independent from but consistent with the Vs model. Our model corroborates the well-established pattern of slow anomalies in the western US, especially in the Basin and Range and Rio Grande Rift regions. New details emerge in the eastern US, thanks to increasing data from the region. A distinction is observed between widespread fast lithospheric anomalies, associated with stable cratonic material, and deeper fast features, associated with the remnants of the Farallon Plate. It has been proposed that these fragments, near the mantle transition zones, still affect mantle dynamics (Forte et al., 2007), so better resolution of these anomalies is an important advancement. In addition, slower velocities are observed beneath the Appalachians and

  3. Lithospheric Structure in Eastern Africa and the Arabian Plate from Joint Inversion of Surface Wave Dispersion Data and Receiver Functions

    NASA Astrophysics Data System (ADS)

    Dugda, M. T.; Nyblade, A. A.; Rodgers, A.; Al-Amri, A.; Julia, J.

    2006-12-01

    Lithospheric structure beneath Eastern Africa (Ethiopia, Kenya, and Djibouti) and the Arabian Shield and Platform has been investigated using a joint inversion of receiver functions and surface wave dispersion measurements from 10 to 175 s. Our models help to constrain the extent of modification made to the lithosphere in the region by hotspot tectonism. Most of the data for this study come from three major sources: the Ethiopia and Kenya Broadband Seismic Experiments which were carried out between 2000-2002 and 2001-2002, respectively, and data from the Saudi Arabia National Digital Seismic Network (KACST). We find that there is little or no seismic lid under the Main Ethiopian Rift and Afar. The results for the Ethiopian Plateau show that there has been thinning of the lithosphere by about ~30 40 km from typical Mozambique Belt lithosphere under Tanzania, which was reported to be up to 120 km thick, and that there has been a reduction in maximum shear wave velocity of the lid by about 7%. Replacement of the bottom of the former Mozambique Belt lithosphere by warm plume material with a partial erosion of the lithosphere can explain both the thinning of the lithosphere and the reduction of maximum velocity. Preliminary results suggest similar lithospheric structure beneath the Arabian Shield. The results from Kenya are similar to that of the results for the Mozambique Belt Lithosphere in Tanzania, showing 100-120 km thick lithosphere.

  4. Prosthetic Joint Infection Diagnosis Using Broad-Range PCR of Biofilms Dislodged from Knee and Hip Arthroplasty Surfaces Using Sonication

    PubMed Central

    Gomez, Eric; Cazanave, Charles; Cunningham, Scott A.; Greenwood-Quaintance, Kerryl E.; Steckelberg, James M.; Uhl, James R.; Hanssen, Arlen D.; Karau, Melissa J.; Schmidt, Suzannah M.; Osmon, Douglas R.; Berbari, Elie F.; Mandrekar, Jayawant

    2012-01-01

    Periprosthetic tissue and/or synovial fluid PCR has been previously studied for prosthetic joint infection (PJI) diagnosis; however, few studies have assessed the utility of PCR on biofilms dislodged from the surface of explanted arthroplasties using vortexing and sonication (i.e., sonicate fluid PCR). We compared sonicate fluid 16S rRNA gene real-time PCR and sequencing to culture of synovial fluid, tissue, and sonicate fluid for the microbiologic diagnosis of PJI. PCR sequences generating mixed chromatograms were decatenated using RipSeq Mixed. We studied sonicate fluids from 135 and 231 subjects with PJI and aseptic failure, respectively. Synovial fluid, tissue, and sonicate fluid culture and sonicate fluid PCR had similar sensitivities (64.7, 70.4, 72.6, and 70.4%, respectively; P > 0.05) and specificities (96.9, 98.7, 98.3, and 97.8%, respectively; P > 0.05). Combining sonicate fluid culture and PCR, the sensitivity was higher (78.5%, P < 0.05) than those of individual tests, with similar specificity (97.0%). Thirteen subjects had positive sonicate fluid culture but negative PCR, and 11 had negative sonicate fluid culture but positive PCR (among which 7 had prior use of antimicrobials). Broad-range PCR and culture of sonicate fluid have equivalent performance for PJI diagnosis. PMID:22895042

  5. Rowing injuries.

    PubMed

    Rumball, Jane S; Lebrun, Constance M; Di Ciacca, Stephen R; Orlando, Karen

    2005-01-01

    Participation in the sport of rowing has been steadily increasing in recent decades, yet few studies address the specific injuries incurred. This article reviews the most common injuries described in the literature, including musculoskeletal problems in the lower back, ribs, shoulder, wrist and knee. A review of basic rowing physiology and equipment is included, along with a description of the mechanics of the rowing stroke. This information is necessary in order to make an accurate diagnosis and treatment protocol for these injuries, which are mainly chronic in nature. The most frequently injured region is the low back, mainly due to excessive hyperflexion and twisting, and can include specific injuries such as spondylolysis, sacroiliac joint dysfunction and disc herniation. Rib stress fractures account for the most time lost from on-water training and competition. Although theories abound for the mechanism of injury, the exact aetiology of rib stress fractures remains unknown. Other injuries discussed within, which are specific to ribs, include costochondritis, costovertebral joint subluxation and intercostal muscle strains. Shoulder pain is quite common in rowers and can be the result of overuse, poor technique, or tension in the upper body. Injuries concerning the forearm and wrist are also common, and can include exertional compartment syndrome, lateral epicondylitis, deQuervain's and intersection syndrome, and tenosynovitis of the wrist extensors. In the lower body, the major injuries reported include generalised patellofemoral pain due to abnormal patellar tracking, and iliotibial band friction syndrome. Lastly, dermatological issues, such as blisters and abrasions, and miscellaneous issues, such as environmental concerns and the female athlete triad, are also included in this article.Pathophysiology, mechanism of injury, assessment and management strategies are outlined in the text for each injury, with special attention given to ways to correct

  6. Diamond-like carbon coatings enhance the hardness and resilience of bearing surfaces for use in joint arthroplasty.

    PubMed

    Roy, M E; Whiteside, L A; Xu, J; Katerberg, B J

    2010-04-01

    The purpose of this study was to evaluate the potential of a hard diamond-like carbon (DLC) coating to enhance the hardness and resilience of a bearing surface in joint replacement. The greater hardness of a magnesium-stabilized zirconium (Mg-PSZ) substrate was expected to provide a harder coating-substrate composite microhardness than the cobalt-chromium alloy (CoCr) also used in arthroplasty. Three femoral heads of each type (CoCr, Mg-PSZ, DLC-CoCr and DLC-Mg-PSZ) were examined. Baseline (non-coated) and composite coating/substrate hardness was measured by Vickers microhardness tests, while nanoindentation tests measured the hardness and elastic modulus of the DLC coating independent of the Mg-PSZ and CoCr substrates. Non-coated Mg-PSZ heads were considerably harder than non-coated CoCr heads, while DLC coating greatly increased the microhardness of the CoCr and Mg-PSZ substrates. On the nanoscale the non-coated heads were much harder than on the microscale, with CoCr exhibiting twice as much plastic deformation as Mg-PSZ. The mechanical properties of the DLC coatings were not significantly different for both the CoCr and Mg-PSZ substrates, producing similar moduli of resilience and plastic resistance ratios. DLC coatings greatly increased hardness on both the micro and nano levels and significantly improved resilience and resistance to plastic deformation compared with non-coated heads. Because Mg-PSZ allows less plastic deformation than CoCr and provides a greater composite microhardness, DLC-Mg-PSZ will likely be more durable for use as a bearing surface in vivo.

  7. Fast pitch softball injuries.

    PubMed

    Meyers, M C; Brown, B R; Bloom, J A

    2001-01-01

    The popularity of fast pitch softball in the US and throughout the world is well documented. Along with this popularity, there has been a concomitant increase in the number of injuries. Nearly 52% of cases qualify as major disabling injuries requiring 3 weeks or more of treatment and 2% require surgery. Interestingly, 75% of injuries occur during away games and approximately 31% of traumas occur during nonpositional and conditioning drills. Injuries range from contusions and tendinitis to ligamentous disorders and fractures. Although head and neck traumas account for 4 to 12% of cases, upper extremity traumas account for 23 to 47% of all injuries and up to 19% of cases involve the knee. Approximately 34 to 42% of injuries occur when the athlete collides with another individual or object. Other factors involved include the quality of playing surface, athlete's age and experience level, and the excessive physical demands associated with the sport. Nearly 24% of injuries involve base running and are due to poor judgement, sliding technique, current stationary base design, unorthodox joint and extremity position during ground impact and catching of cleats. The increasing prevalence of overtraining syndrome among athletes has been attributed to an unclear definition of an optimal training zone, poor communication between player and coach, and the limited ability of bone and connective tissue to quickly respond to match the demands of the sport. This has led routinely to arm, shoulder and lumbar instability, chronic nonsteroidal anti-inflammatory drug (NSAID) use and time loss injuries in 45% of pitching staff during a single season. Specific attention to a safer playing environment, coaching and player education, and sport-specific training and conditioning would reduce the risk, rate and severity of fast pitch traumas. Padding of walls, backstops, rails and dugout areas, as well as minimising use of indoor facilities, is suggested to decrease the number of collision

  8. Surface Characterizations of Fretting Fatigue Damage in Aluminum Alloy 7075-T6 Clamped Joints: The Beneficial Role of Ni–P Coatings

    PubMed Central

    Oskouei, Reza H.; Barati, Mohammad Reza; Ibrahim, Raafat N.

    2016-01-01

    This paper aims to characterize the surface damage as a consequence of fretting fatigue in aluminum alloy 7075-T6 plates in double-lap bolted joints through XRD, surface profilometry, and SEM analyses. The main focus was on the surface roughness and chemical phase composition of the damaged zone along with the identification of fretting fatigue crack initiations over the surface of the material. The surface roughness of the fretted zone was found to increase when the joint was clamped with a higher tightening torque and tested under the same cyclic loading. Additionally, MgZn2 (η/ή) precipitates and ZnO phase were found to form onto the surface of uncoated aluminum plate in the fretted and worn zones. The formation of the ZnO phase was understood to be a result of frictional heat induced between the surface of contacting uncoated Al 7075-T6 plates during cyclic loading and exposure to the air. The beneficial role of electroless nickel-phosphorous (Ni–P) coatings in minimizing the fretting damage and thus improving the fretting fatigue life of the aluminum plates was also studied. The results showed that the surface roughness decreased by approximately 40% after applying Ni–P coatings to the Al 7075-T6 plates. PMID:28773267

  9. Atomic force microscopy visualization of injuries in Enterococcus faecalis surface caused by Er,Cr:YSGG and diode lasers

    PubMed Central

    López-Jiménez, Lidia; Viñas, Miguel; Vinuesa, Teresa

    2015-01-01

    Aim: To visualize by Atomic Force Microscopy the alterations induced on Enterococcus. faecalis surface after treatment with 2 types of laser: Erbium chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and Diode laser. Material and Methods: Bacterial suspensions from overnight cultures of E. faecalis were irradiated during 30 seconds with the laser-lights at 1 W and 2 W of power, leaving one untreated sample as control. Surface alterations on treated E. faecalis were visualized by Atomic Force Microscopy (AFM) and its surface roughness determined. Results: AFM imaging showed that at high potency of laser both cell morphology and surface roughness resulted altered, and that several cell lysis signs were easily visualized. Surface roughness clearly increase after the treatment with Er,Cr:YSGG at 2W of power, while the other treatments gave similar values of surface roughness. The effect of lasers on bacterial surfaces visualized by AFM revealed drastic alterations. Conclusions: AFM is a good tool to evaluate surface injuries after laser treatment; and could constitute a measure of antimicrobial effect that can complete data obtained by determination of microbial viability. Key words:Atomic force microscopy, Er,Cr:YSGG laser, diode laser, Enterococcus faecalis, surface roughness. PMID:25475770

  10. Volleyball injuries.

    PubMed

    Eerkes, Kevin

    2012-01-01

    There has been a significant increase in the numbers of people playing indoor and beach volleyball since the early 1980s and, consequently, an increase in injuries. Most injuries are related to repetitive jumping and hitting the ball overhead. The ankle is the most commonly injured joint, but the knee, shoulder, low back, and fingers also are vulnerable. The shoulder in particular is subject to extreme torque when hitting and jump serving the ball. Some injuries have a predilection for those playing on sand versus those playing in an indoor court. The clinician caring for volleyball players should be aware of the types of injuries these players sustain and how to help them return to play promptly and appropriately. This article reviews the specific injuries that are most common as a result of participating in the sport of volleyball.

  11. Joint Inversion of Body-Wave Arrival Times and Surface-Wave Dispersion Data in the Wavelet Domain Constrained by Sparsity Regularization

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Fang, H.; Yao, H.; Maceira, M.; van der Hilst, R. D.

    2014-12-01

    Recently, Zhang et al. (2014, Pure and Appiled Geophysics) have developed a joint inversion code incorporating body-wave arrival times and surface-wave dispersion data. The joint inversion code was based on the regional-scale version of the double-difference tomography algorithm tomoDD. The surface-wave inversion part uses the propagator matrix solver in the algorithm DISPER80 (Saito, 1988) for forward calculation of dispersion curves from layered velocity models and the related sensitivities. The application of the joint inversion code to the SAFOD site in central California shows that the fault structure is better imaged in the new model, which is able to fit both the body-wave and surface-wave observations adequately. Here we present a new joint inversion method that solves the model in the wavelet domain constrained by sparsity regularization. Compared to the previous method, it has the following advantages: (1) The method is both data- and model-adaptive. For the velocity model, it can be represented by different wavelet coefficients at different scales, which are generally sparse. By constraining the model wavelet coefficients to be sparse, the inversion in the wavelet domain can inherently adapt to the data distribution so that the model has higher spatial resolution in the good data coverage zone. Fang and Zhang (2014, Geophysical Journal International) have showed the superior performance of the wavelet-based double-difference seismic tomography method compared to the conventional method. (2) For the surface wave inversion, the joint inversion code takes advantage of the recent development of direct inversion of surface wave dispersion data for 3-D variations of shear wave velocity without the intermediate step of phase or group velocity maps (Fang et al., 2014, Geophysical Journal International). A fast marching method is used to compute, at each period, surface wave traveltimes and ray paths between sources and receivers. We will test the new joint

  12. Traumatic proximal interphalangeal joint reconstruction with an autologous hemi-toe osteochondral graft: case report.

    PubMed

    Pirani, Asif A; Rao, Ajit; Sharma, Sheel

    2013-07-01

    We report a case of a traumatic proximal interphalangeal joint injury with loss of the middle phalangeal base and articular surface, which was reconstructed with an autologous hemi-toe osteochondral graft. The patient had a 72° improvement in proximal interphalangeal joint motion and excellent functional improvements. Postoperative computed tomography imaging indicated bony union and articular congruence. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  13. Developing a burn injury severity score (BISS): adding age and total body surface area burned to the injury severity score (ISS) improves mortality concordance.

    PubMed

    Cassidy, J Tristan; Phillips, Michael; Fatovich, Daniel; Duke, Janine; Edgar, Dale; Wood, Fiona

    2014-08-01

    There is limited research validating the injury severity score (ISS) in burns. We examined the concordance of ISS with burn mortality. We hypothesized that combining age and total body surface area (TBSA) burned to the ISS gives a more accurate mortality risk estimate. Data from the Royal Perth Hospital Trauma Registry and the Royal Perth Hospital Burns Minimum Data Set were linked. Area under the receiver operating characteristic curve (AUC) measured concordance of ISS with mortality. Using logistic regression models with death as the dependent variable we developed a burn-specific injury severity score (BISS). There were 1344 burns with 24 (1.8%) deaths, median TBSA 5% (IQR 2-10), and median age 36 years (IQR 23-50). The results show ISS is a good predictor of death for burns when ISS≤15 (OR 1.29, p=0.02), but not for ISS>15 (ISS 16-24: OR 1.09, p=0.81; ISS 25-49: OR 0.81, p=0.19). Comparing the AUCs adjusted for age, gender and cause, ISS of 84% (95% CI 82-85%) and BISS of 95% (95% CI 92-98%), demonstrated superior performance of BISS as a mortality predictor for burns. ISS is a poor predictor of death in severe burns. The BISS combines ISS with age and TBSA and performs significantly better than the ISS. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  14. A new algorithm for three-dimensional joint inversion of body wave and surface wave data and its application to the Southern California plate boundary region

    NASA Astrophysics Data System (ADS)

    Fang, Hongjian; Zhang, Haijiang; Yao, Huajian; Allam, Amir; Zigone, Dimitri; Ben-Zion, Yehuda; Thurber, Clifford; van der Hilst, Robert D.

    2016-05-01

    We introduce a new algorithm for joint inversion of body wave and surface wave data to get better 3-D P wave (Vp) and S wave (Vs) velocity models by taking advantage of the complementary strengths of each data set. Our joint inversion algorithm uses a one-step inversion of surface wave traveltime measurements at different periods for 3-D Vs and Vp models without constructing the intermediate phase or group velocity maps. This allows a more straightforward modeling of surface wave traveltime data with the body wave arrival times. We take into consideration the sensitivity of surface wave data with respect to Vp in addition to its large sensitivity to Vs, which means both models are constrained by two different data types. The method is applied to determine 3-D crustal Vp and Vs models using body wave and Rayleigh wave data in the Southern California plate boundary region, which has previously been studied with both double-difference tomography method using body wave arrival times and ambient noise tomography method with Rayleigh and Love wave group velocity dispersion measurements. Our approach creates self-consistent and unique models with no prominent gaps, with Rayleigh wave data resolving shallow and large-scale features and body wave data constraining relatively deeper structures where their ray coverage is good. The velocity model from the joint inversion is consistent with local geological structures and produces better fits to observed seismic waveforms than the current Southern California Earthquake Center (SCEC) model.

  15. The spatial organisation of joint surface chondrocytes: review of its potential roles in tissue functioning, disease and early, preclinical diagnosis of osteoarthritis.

    PubMed

    Aicher, Wilhelm K; Rolauffs, Bernd

    2014-04-01

    Chondrocytes display within the articular cartilage depth-dependent variations of their many properties that are comparable to the depth-dependent changes of the properties of the surrounding extracellular matrix. However, not much is known about the spatial organisation of the chondrocytes throughout the tissue. Recent studies revealed that human chondrocytes display distinct spatial patterns of organisation within the articular surface, and each joint surface is dominated in a typical way by one of four basic spatial patterns. The resulting complex spatial organisations correlate with the specific diarthrodial joint type, suggesting an association of the chondrocyte organisation within the joint surface with the occurring biomechanical forces. In response to focal osteoarthritis (OA), the superficial chondrocytes experience a destruction of their spatial organisation within the OA lesion, but they also undergo a defined remodelling process distant from the OA lesion in the remaining, intact cartilage surface. One of the biological insights that can be derived from this spatial remodelling process is that the chondrocytes are able to respond in a generalised and coordinated fashion to distant focal OA. The spatial characteristics of this process are tremendously different from the cellular aggregations typical for OA lesions, suggesting differences in the underlying mechanisms. Here we summarise the available information on the spatial organisation of chondrocytes and its potential roles in cartilage functioning. The spatial organisation could be used to diagnose early OA onset before manifest OA results in tissue destruction and clinical symptoms. With further development, this concept may become clinically suitable for the diagnosis of preclinical OA.

  16. Lubrication of the human ankle joint in walking with the synovial fluid filtrated by the cartilage with the surface zone worn out: steady pure sliding motion.

    PubMed

    Hlavácek, M

    1999-10-01

    A mixture model of synovial fluid filtration by cartilage in the human ankle joint during walking is presented for steady sliding motion of the articular surfaces. In the paper the cartilage surface zone is assumed worn out. The same model has been recently applied to the squeeze-film problem for the human hip joint loaded by the body weight during standing (Hlavácek, Journal of Biomechanics 26, 1145-1150, 1151-1160, 1993; Hlavácek and Novák, Journal of Biomechanics 28, 1193-1198, 1199-1205, 1995). The linear biphasic model for cartilage (elastic porous matrix + ideal fluid) due to Prof. V. C. Mow and his co-workers and the biphasic model for synovial fluid (viscous fluid + ideal fluid), as used in the above-mentioned squeeze-film problem, are applied. For the physiologic parameters of the ankle joint during walking, a continuous synovial fluid film about 1 microm thick is maintained under steady entraining motion according to the classical model without the fluid transport across the articular surface. This is not the case in the filtration model with the cartilage surface zones worn out. On the contrary, this filtration model indicates that synovial fluid is intensively filtrated by such cartilage, so that no continuous fluid film is maintained and a synovial gel layer, about 10(-8) m thick, develops over the majority of the contact. Thus, if the cartilage surface zones are worn out, boundary lubrication should prevail in the ankle joint under steady sliding motion for the mean values of loading and the sliding velocity encountered in walking cycle.

  17. A Study on the Effect of Ageing and Intermetallic Compound Growth on the Shear Strength of Surface Mount Technology Solder Joints

    NASA Astrophysics Data System (ADS)

    Nath, Jyotishman; Mallik, Sabuj; Borah, Anil

    2015-04-01

    The effect of ageing and intermetallic compound formation on the surface mount solder joints and its shear strength behavior under extreme mechanical and thermal conditions have been discussed in this paper. The specimens used are solder paste (Sn3.8Ag0.7Cu), bench marker II printed circuit boards (PCB), resistors 1206 and the fabrication of solder joints makes use of conventional surface mount technology (SMT). Reflow process was carried out at a peak temperature of 250 °C and the test samples were exposed to isothermal ageing at a constant temperature of 150 °C for a period of 600 h. Shear test was conducted on the PCB's. The shear strength of the solder joints rapidly increased during isothermal ageing to a certain time period and then started decreasing. Field emission scanning electron microscopy (FESEM) micrograph of the solder joint and energy dispersive X-ray (EDX) was performed on the solder sample to verify the formation of intermetallic compounds.

  18. Elastohydrodynamic lubrication analysis of a functionally graded layered bearing surface, with particular reference to 'cushion form bearings' for artificial knee joints.

    PubMed

    Virdee, S S; Wang, F C; Xu, H; Jin, Z M

    2003-01-01

    Elastohydrodynamic lubrication of a functionally graded layered (FGL) bearing surface, whose elastic modulus increases with depth from the bearing surface, was investigated in this study. The finite difference method was employed to solve the Reynolds equation, simultaneously with the elasticity equation of the bearing surface, under circular point contacts. The finite element method was adopted to solve the elasticity equation for the FGL bearing surface. The displacement coefficients thus obtained were used to calculate the elastic deformation of the bearing surface, required for the elastohydrodynamic lubrication analysis. Good agreement of the predicted film thickness and pressure distribution was obtained, between the present method and a previous study for a single layered bearing surface with a uniform elastic modulus. The general numerical methodology was then applied to an FGL bearing surface with both linear and exponential variations in elastic modulus, with particular reference to the 'cushion form bearing' for artificial knee joints. The predicted film thickness and pressure distribution were shown to be quite close to those obtained for a single layer under typical operating conditions representative of artificial knee joints, provided that the elastic modulus of the single layer was chosen to be the average elastic modulus of the graded layer.

  19. Atomic force microscopy visualization of injuries in Enterococcus faecalis surface caused by Er,Cr:YSGG and diode lasers.

    PubMed

    López-Jiménez, Lidia; Arnabat-Domínguez, Josep; Viñas, Miguel; Vinuesa, Teresa

    2015-01-01

    To visualize by atomic force microscopy the alterations induced on Enterococcus. faecalis surface after treatment with 2 types of laser: Erbium chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and Diode laser. Bacterial suspensions from overnight cultures of E. faecalis were irradiated during 30 seconds with the laser-lights at 1 W and 2 W of power, leaving one untreated sample as control. Surface alterations on treated E. faecalis were visualized by atomic force microscopy (AFM) and its surface roughness determined. AFM imaging showed that at high potency of laser both cell morphology and surface roughness resulted altered, and that several cell lysis signs were easily visualized. Surface roughness clearly increase after the treatment with Er,Cr:YSGG at 2W of power, while the other treatments gave similar values of surface roughness. The effect of lasers on bacterial surfaces visualized by AFM revealed drastic alterations. AFM is a good tool to evaluate surface injuries after laser treatment; and could constitute a measure of antimicrobial effect that can complete data obtained by determination of microbial viability.

  20. Posterolateral surface electrical stimulation of abdominal expiratory muscles to enhance cough in spinal cord injury.

    PubMed

    Butler, Jane E; Lim, Julianne; Gorman, Robert B; Boswell-Ruys, Claire; Saboisky, Julian P; Lee, Bonsan B; Gandevia, Simon C

    2011-02-01

    Spinal cord injury (SCI) patients have respiratory complications because of abdominal muscle weakness and paralysis, which impair the ability to cough. This study aims to enhance cough in high-level SCI subjects (n = 11, SCI at or above T6) using surface electrical stimulation of the abdominal muscles via 2 pairs of posterolaterally placed electrodes. From total lung capacity, subjects performed maximum expiratory pressure (MEP) efforts against a closed airway and voluntary cough efforts. Both efforts were performed with and without superimposed trains of electrical stimulation (50 Hz, 1 second) at a submaximal intensity set to evoke a gastric pressure (P(ga)) of 40 cm H(2)O at functional residual capacity. In the MEP effort, stimulation increased the maximal P(ga) (from 21.4 ± 7.0 to 59.0 ± 5.7 cm H(2)O) and esophageal pressure (P(es); 47.2 ± 11.7 to 65.6 ± 13.6 cm H(2)O). During the cough efforts, stimulation increased P(ga) (19.5 ± 6.0 to 57.9 ± 7.0 cm H(2)O) and P(es) (31.2 ± 8.7 to 56.6 ± 10.5 cm H(2)O). The increased expiratory pressures during cough efforts with stimulation increased peak expiratory flow (PEF, by 36% ± 5%), mean expiratory flow (by 80% ± 8%), and expired lung volume (by 41% ± 16%). In every subject, superimposed electrical stimulation improved peak expiratory flow during cough efforts (by 0.99 ± 0.12 L/s; range, 0.41-1.80 L/s). Wearing an abdominal binder did not improve stimulated cough flows or pressures. The increases in P(ga) and PEF with electrical stimulation using the novel posterolateral electrode placement are 2 to 3 times greater than improvements reported in other studies. This suggests that posterolateral electrical stimulation of abdominal muscles is a simple noninvasive way to enhance cough in individuals with SCI.

  1. The effect of the dimensions of the distal femur and proximal tibia joint surfaces on the development of knee osteoarthritis.

    PubMed

    Işik, Derya; Işik, Çetin; Apaydin, Nihal; Üstü, Yusuf; Uğurlu, Mahmut; Bozkurt, Murat

    2015-07-01

    The aim of this study was to determine whether the dimensions of the distal femur and proximal tibia joint surfaces affect the etiology of knee osteoarthritis (OA). The study comprised the records of 1,324 patients who had been admitted to hospital with knee pain. Anterioposterior (AP) and lateral radiographs of the knee were taken. Using the Kellgren-Lawrence Scale, the patient group comprised Stages 2, 3, and 4 radiographs and the controls comprised Stages 0 and 1 radiographs. Four lengths were measured for each patient in both groups: femur mediolateral (femur ML), tibia mediolateral (tibia ML), femur anteroposterior (femur AP), and tibia anteroposterior (tibia AP). Osteophytes were not included in the measurements in the patient group. All the measurements were repeated by two researchers at two different times. The groups were compared in terms of these measurements and the correlations between them. The mean femur ML length was significantly greater in the patient group than the control group (P = 0.032) and the mean femur AP length was significantly less (P = 0.037). In addition, the difference between the femur ML and AP lengths was significantly high in the patient group (P < 0.001). The difference between the tibia and femur ML lengths was significantly high in the patient group (P < 0.001) and the difference between the tibia and femur AP lengths was higher in the control group (P = 0.001). A longer femur ML and a shorter femur AP, together with a greater difference between these two lengths and a greater difference between the tibia ML and femur ML lengths, could be a risk factor for developing knee OA. More extensive anatomical and biomechanical studies in the future will enable these results to be corroborated.

  2. Prediction of the Properties of Heat-Affected Zone of Welded Joints of Sheets from Aluminum Alloys with Structured Surface

    NASA Astrophysics Data System (ADS)

    Mikhailov, V. G.

    2016-05-01

    Welded joints of light structured sheets from aluminum alloy EN AW-6181-T4 (DIN EN 515) of the Al - Si - Mg system are studied. The welding is performed in an argon environment with a short arc by the method of cold metal transfer (CMT®). The results of the study are used in an amended Leblond model for describing the variation of the properties of the heat-affected zone of welded joints of structured sheets.

  3. Elbow joint angle and elbow movement velocity estimation using NARX-multiple layer perceptron neural network model with surface EMG time domain parameters.

    PubMed

    Raj, Retheep; Sivanandan, K S

    2017-01-01

    Estimation of elbow dynamics has been the object of numerous investigations. In this work a solution is proposed for estimating elbow movement velocity and elbow joint angle from Surface Electromyography (SEMG) signals. Here the Surface Electromyography signals are acquired from the biceps brachii muscle of human hand. Two time-domain parameters, Integrated EMG (IEMG) and Zero Crossing (ZC), are extracted from the Surface Electromyography signal. The relationship between the time domain parameters, IEMG and ZC with elbow angular displacement and elbow angular velocity during extension and flexion of the elbow are studied. A multiple input-multiple output model is derived for identifying the kinematics of elbow. A Nonlinear Auto Regressive with eXogenous inputs (NARX) structure based multiple layer perceptron neural network (MLPNN) model is proposed for the estimation of elbow joint angle and elbow angular velocity. The proposed NARX MLPNN model is trained using Levenberg-marquardt based algorithm. The proposed model is estimating the elbow joint angle and elbow movement angular velocity with appreciable accuracy. The model is validated using regression coefficient value (R). The average regression coefficient value (R) obtained for elbow angular displacement prediction is 0.9641 and for the elbow anglular velocity prediction is 0.9347. The Nonlinear Auto Regressive with eXogenous inputs (NARX) structure based multiple layer perceptron neural networks (MLPNN) model can be used for the estimation of angular displacement and movement angular velocity of the elbow with good accuracy.

  4. Incidence, Mechanisms, and Severity of Match-Related Collegiate Men's Soccer Injuries on FieldTurf and Natural Grass Surfaces: A 6-Year Prospective Study.

    PubMed

    Meyers, Michael C

    2017-03-01

    Numerous injuries have been attributed to playing on artificial turf. More recently, newer generations of artificial turf have been developed to duplicate the playing characteristics of natural grass. Although artificial turf has been deemed safer than natural grass in some studies, few long-term studies have been conducted comparing match-related collegiate soccer injuries between the 2 playing surfaces. Collegiate male soccer athletes do not experience any difference in the incidence, mechanisms, or severity of match-related injuries between FieldTurf and natural grass. Cohort study; Level of evidence, 2. Male soccer athletes from 11 universities were evaluated over 6 seasons. Demographic features and predictors included player position, cleat design, player weight, turf age, and environmental factors. Outcomes of interest included injury incidence, injury category, time loss, injury mechanism and situation, type of injury, injury grade and anatomic location, injury severity, head and lower extremity trauma, and elective medical procedures. All match-related injuries were evaluated by the attending head athletic trainer and team physicians on site and subsequently in the physician's office when further follow-up and treatment were deemed necessary. In sum, 765 collegiate games were evaluated for match-related soccer injuries sustained on FieldTurf or natural grass during 6 seasons. Overall, 380 team games (49.7%) were played on FieldTurf versus 385 team games (50.3%) played on natural grass. A total of 722 injuries were documented, with 268 (37.1%) occurring on FieldTurf and 454 (62.9%) on natural grass. Multivariate analysis per 10 team games indicated a significant playing surface effect: F2,720 = 7.260, P = .001. A significantly lower total injury incidence rate (IIR) of 7.1 (95% CI, 6.6-7.5) versus 11.8 (95% CI, 11.3-12.2; P < .0001) and lower rate of substantial injuries, 0.7 (95% CI, 0.5-1.0) versus 1.9 (95% CI, 1.5-2.3; P < .03), were documented on Field

  5. [Therapeutic algorithm for traumatic cartilage injuries].

    PubMed

    Miltner, Oliver; Hagemann, Lars; Ristan, Steven; Siebert, Christian H

    2009-02-01

    Reports regarding sport injuries frequently pertain to the knee. Although ligament and meniscus damage are the most common, cartilage injuries are of great interest. Even with the great variety of treatment modalities available, the healing of these cartilage injuries remains problematic. Due to the complex structure of hyaline cartilage joint surface, repair has proven to be very difficult. The conservative treatment options range from orthotic devices and physical therapy to systemic and intraarticular medication. In case of failure, a wide variety of surgical interventions exist. Among these surgical treatment forms, one must differentiate between the repair and the reconstruction of hyaline joint surfaces. In the latter group only the osteochondral autologous transplantation procedures allow for the reconstruction of a cartilaginous lesion with hyaline cartilage as part of a single procedure. This paper will provide an overview of most common therapeutic approaches to cartilage injuries available today. Even with the ongoing discussions with regard to cartilage healing, the basics such as the ligamentous stability of the affected joint, the mechanical axis of the extremity and good neuromuscular control must always be part of the algorithm.

  6. Factors associated with upper extremity contractures after cervical spinal cord injury: A pilot study.

    PubMed

    Hardwick, Dustin; Bryden, Anne; Kubec, Gina; Kilgore, Kevin

    2017-06-05

    To examine the prevalence of joint contractures in the upper limb and association with voluntary strength, innervation status, functional status, and demographics in a convenience sample of individuals with cervical spinal cord injury to inform future prospective studies. Cross-sectional convenience sampled pilot study. Department of Veterans Affairs Research Laboratory. Thirty-eight participants with cervical level spinal cord injury. Not applicable. Contractures were measured with goniometric passive range of motion. Every joint in the upper extremity was evaluated bilaterally. Muscle strength was measured with manual muscle testing. Innervation status was determined clinically with surface electrical stimulation. Functional independence was measured with the Spinal Cord Independence Measure III (SCIM-III). Every participant tested had multiple joints with contractures and, on average, participants were unable to achieve the normative values of passive movement in 52% of the joints tested. Contractures were most common in the shoulder and hand. There was a weak negative relationship between percentage of contractures and time post-injury and a moderat