Sample records for ac joint reconstruction

  1. Acromioclavicular joint dislocations: coracoclavicular reconstruction with and without additional direct acromioclavicular repair.

    PubMed

    Weiser, Lukas; Nüchtern, Jakob V; Sellenschloh, Kay; Püschel, Klaus; Morlock, Michael M; Rueger, Johannes M; Hoffmann, Michael; Lehmann, Wolfgang; Großterlinden, Lars G

    2017-07-01

    To evaluate different stabilisation techniques for acromioclavicular (AC) joint separations, including direct AC repair, and to compare the properties of the stabilised and native joints. An established in vitro testing model for the AC joint was used to analyse joint stability after surgical reconstruction [double TightRope (DTR), DTR with AC repair (DTR + AC), single TR with AC repair (TR + AC), and PDS sling with AC repair (PDS + AC)]. Twenty-four human cadaveric shoulders were randomised by age into four testing groups. Joint stiffness was measured by applying an axial load during defined physiological ranges of motion. Similar tests were performed for the native joints, after dissecting the coracoclavicular and AC ligaments, and after surgical reconstruction. Cyclic loading was performed for 1000 cycles with 20-70 N and vertical load to failure determined after cyclic testing. Axial stiffness for all TR groups was significantly higher than for the native joint (DTR 38.94 N/mm, p = 0.005; DTR + AC 37.79 N/mm, p = 0.015; TR + AC 45.61 N/mm, p < 0.001 vs. native 26.05 N/mm). The axial stiffness of the PDS + AC group was similar to that of the native joint group (21.4 N/mm, n.s.). AC repair did not significantly influence rotational stiffness. Load to failure was similar and >600 N in all groups (n.s.). Reconstruction of AC dislocations with one or two TRs leads to stable results with a higher stiffness than the native joints. For the PDS + AC group, axial stiffness was similar to the native situation, although there might be a risk of elongation. Direct AC repair showed no significantly increased stability in comparison with reconstructions without direct AC repair. Thus, a direct AC repair seems to be dispensable in clinical practice, while TRs or PDS cerclages appear to provide sufficiently stable results.

  2. Biomechanical evaluation of native acromioclavicular joint ligaments and two reconstruction techniques in the presence of the sternoclavicular joint: A cadaver study.

    PubMed

    Masionis, Povilas; Šatkauskas, Igoris; Mikelevičius, Vytautas; Ryliškis, Sigitas; Bučinskas, Vytautas; Griškevičius, Julius; Martin Oliva, Xavier; Monzó Planella, Mariano; Porvaneckas, Narūnas; Uvarovas, Valentinas

    2017-01-01

    Where is over 100 reconstruction techniques described for acromioclavicular (AC) joint reconstruction. Although, it is not clear whether the presence of the sternoclavicular (SC) joint influences the biomechanical properties of native AC ligaments and reconstruction techniques. The purpose of the present study was to investigate the biomechanical properties of native AC joint ligaments and two reconstruction techniques in cadavers with the SC joint still present. We tested eight fresh-frozen cadaver hemithoraces for superior translation (70 N load) and translation increment after 1000 cycles (loading from 20 to 70 N) in a controlled laboratory study. There were three testing groups created: native ligaments, the single coracoclavicular loop (SCL) technique, and the two coracoclavicular loops (TCL) technique. Superior translation was measured after static loading. Translation increment was calculated as the difference between superior translation after cyclic and static loading. Native AC ligaments showed significantly lower translation than the SCL ( p = 0.023) and TCL ( p = 0.046) groups. The SCL had a significantly lower translation increment than native AC ligaments ( p = 0.028). There was no significant difference between reconstruction techniques in terms of translation ( p = 0.865) and translation increment ( p = 0.113). Native AC joint ligaments had better static properties than both reconstruction techniques and worse dynamic biomechanical properties than the SCL technique. The SCL technique appeared to be more secure than the TCL technique. The presence of the SC joint did not have an observable influence on test results.

  3. Biomechanical Comparison of an Intramedullary and Extramedullary Free-Tissue Graft Reconstruction of the Acromioclavicular Joint Complex

    PubMed Central

    Garg, Rishi; Javidan, Pooya; Lee, Thay Q.

    2013-01-01

    Background Several different surgical techniques have been described to address the coracoclavicular (CC) ligaments in acromioclavicular (AC) joint injuries. However, very few techniques focus on reconstructing the AC ligaments, despite its importance in providing stability. The purpose of our study was to compare the biomechanical properties of two free-tissue graft techniques that reconstruct both the AC and CC ligaments in cadaveric shoulders, one with an extramedullary AC reconstruction and the other with an intramedullary AC reconstruction. We hypothesized intramedullary AC reconstruction will provide greater anteroposterior translational stability and improved load to failure characteristics than an extramedullary technique. Methods Six matched cadaveric shoulders underwent translational testing at 10 N and 15 N in the anteroposterior and superoinferior directions, under AC joint compression loads of 10 N, 20 N, and 30 N. After the AC and CC ligaments were transected, one of the specimens was randomly assigned the intramedullary free-tissue graft reconstruction while its matched pair received the extramedullary graft reconstruction. Both reconstructed specimens then underwent repeat translational testing, followed by load to failure testing, via superior clavicle distraction, at a rate of 50 mm/min. Results Intramedullary reconstruction provided significantly greater translational stability in the anteroposterior direction than the extramedullary technique for four of six loading conditions (p < 0.05). There were no significant differences in translational stability in the superoinferior direction for any loading condition. The intramedullary reconstructed specimens demonstrated improved load to failure characteristics with the intramedullary reconstruction having a lower deformation at yield and a higher ultimate load than the extramedullary reconstruction (p < 0.05). Conclusions Intramedullary reconstruction of the AC joint provides greater stability in the

  4. Rotational and translational stability of different methods for direct acromioclavicular ligament repair in anatomic acromioclavicular joint reconstruction.

    PubMed

    Beitzel, Knut; Obopilwe, Elifho; Apostolakos, John; Cote, Mark P; Russell, Ryan P; Charette, Ryan; Singh, Hardeep; Arciero, Robert A; Imhoff, Andreas B; Mazzocca, Augustus D

    2014-09-01

    Many reconstructions of acromioclavicular (AC) joint dislocations have focused on the coracoclavicular (CC) ligaments and neglected the functional contribution of the AC ligaments and the deltotrapezial fascia. To compare the modifications of previously published methods for direct AC reconstruction in addition to a CC reconstruction. The hypothesis was that there would be significant differences within the variations of surgical reconstructions. Controlled laboratory study. A total of 24 cadaveric shoulders were tested with a servohydraulic testing system. Two digitizing cameras evaluated the 3-dimensional movement. All reconstructions were based on a CC reconstruction using 2 clavicle tunnels and a tendon graft. The following techniques were used to reconstruct the AC ligaments: a graft was shuttled underneath the AC joint back from anterior and again sutured to the acromial side of the joint (group 1), a graft was fixed intramedullary in the acromion and distal clavicle (group 2), a graft was passed over the acromion and into an acromial tunnel (group 3), and a FiberTape was fixed in a cruciate configuration (group 4). Anterior, posterior, and superior translation, as well as anterior and posterior rotation, were tested. Group 1 showed significantly less posterior translation compared with the 3 other groups (P < .05) but did not show significant differences compared with the native joint. Groups 3 and 4 demonstrated significantly more posterior translation than the native joint. Group 1 showed significantly less anterior translation compared with groups 2 and 3. Group 3 demonstrated significantly more anterior translation than the native joint. Group 1 demonstrated significantly less superior translation compared with the other groups and with the native joint. The AC joint of group 1 was pulled apart less compared with all other reconstructions. Only group 1 reproduced the native joint for the anterior rotation at the posterior marker. Group 4 showed

  5. Arthroscopically Assisted Reconstruction of Acute Acromioclavicular Joint Dislocations: Anatomic AC Ligament Reconstruction With Protective Internal Bracing—The “AC-RecoBridge” Technique

    PubMed Central

    Izadpanah, Kaywan; Jaeger, Martin; Ogon, Peter; Südkamp, Norbert P.; Maier, Dirk

    2015-01-01

    An arthroscopically assisted technique for the treatment of acute acromioclavicular joint dislocations is presented. This pathology-based procedure aims to achieve anatomic healing of both the acromioclavicular ligament complex (ACLC) and the coracoclavicular ligaments. First, the acromioclavicular joint is reduced anatomically under macroscopic and radiologic control and temporarily transfixed with a K-wire. A single-channel technique using 2 suture tapes provides secure coracoclavicular stabilization. The key step of the procedure consists of the anatomic repair of the ACLC (“AC-Reco”). Basically, we have observed 4 patterns of injury: clavicular-sided, acromial-sided, oblique, and midportion tears. Direct and/or transosseous ACLC repair is performed accordingly. Then, an X-configured acromioclavicular suture tape cerclage (“AC-Bridge”) is applied under arthroscopic assistance to limit horizontal clavicular translation to a physiological extent. The AC-Bridge follows the principle of internal bracing and protects healing of the ACLC repair. The AC-Bridge is tightened on top of the repair, creating an additional suture-bridge effect and promoting anatomic ACLC healing. We refer to this combined technique of anatomic ACLC repair and protective internal bracing as the “AC-RecoBridge.” A detailed stepwise description of the surgical technique, including indications, technical pearls and pitfalls, and potential complications, is given. PMID:26052493

  6. Open capsular and ligament reconstruction with semitendinosus hamstring autograft successfully controls superior and posterior translation for type V acromioclavicular joint dislocation.

    PubMed

    Garofalo, Raffaele; Ceccarelli, Enrico; Castagna, Alessandro; Calvisi, Vittorio; Flanagin, Brody; Conti, Marco; Krishnan, Sumant G

    2017-07-01

    Appropriate surgical management for type V complete acromioclavicular (AC) joint dislocation remains controversial. The purpose of this paper is to retrospectively report the clinical and radiographic outcomes of an open surgical technique consisting for AC joint ligamentous and capsular reconstruction using autologous hamstring tendon grafts and semi-permanent sutures. Between January 2005 and December 2011, 32 consecutive patients with symptomatic type V complete AC joint dislocation underwent surgical treatment using the same technique. The median time from injury to surgery was 45 days (range 24-90). The average median postoperative clinical and radiographic follow-up time was 30 months (range 24-33). Clinical outcomes measures included the ASES score, the visual analog score (VAS), and subjective patient satisfaction score. Minimum follow-up was 2 years. ASES score increased from a median of 38.2 ± 6.2 preoperative to 92.1 ± 4.7 postoperatively (p ≤ 0.05). The median VAS score improved from 62 mm (range 45-100 mm) preoperatively to 8 mm (range 0-20 mm) at final follow-up (p ≤ 0.05). No patient experienced pain or discomfort with either direct palpation of the AC joint or with cross-body adduction. Final radiographs demonstrated symmetric AC joint contour in 25/32 (78%) patients. Seven patients (22%) radiographically demonstrated superior translation of the distal clavicle relative to the superior margin of the acromion but less than 50% of the clavicular width. 30/32 patients (93%) were able to return to their pre-injury level of work and sports activities. This novel surgical technique using a free graft and braided suture for simultaneous coracoclavicular ligament and AC joint capsular reconstruction successfully controls superior and posterior translations after type V AC joint dislocation and minimizes the incidence of persistent postoperative AC joint subluxation. Retrospective case series, Level IV.

  7. Surgical treatment of acute type V acromioclavicular joint dislocations in professional athletes: an anatomic ligament reconstruction with synthetic implant augmentation.

    PubMed

    Triantafyllopoulos, Ioannis K; Lampropoulou-Adamidou, Kalliopi; Schizas, Nikitas P; Karadimas, Eleftherios V

    2017-12-01

    Most acromioclavicular (AC) joint injuries occur in men in their third decade of life during high-speed or high-impact body contact sports. The management of acute complete AC joint dislocation is surgical. Current surgical techniques include anatomic reconstruction of the main restraints of the AC joint and aim to improve functional outcomes and to reduce the complication rate. We present 10 cases of acute type V AC joint dislocation in professional athletes treated surgically with anatomic reconstruction of the coracoclavicular and AC ligaments and augmentation with the use of a synthetic polyester tape. The minimum follow-up of the patients was 2 years (mean, 48 months; range, 24-86 months). The postoperative functional outcome was assessed at 1 year and 2 years using the Constant-Murley, American Shoulder and Elbow Surgeons, and modified University of California-Los Angeles scoring systems. In all cases, the postoperative scores were significantly improved (P < .005 in all comparisons with the preoperative scores), and all patients returned to their preinjury high level of activity 6 months postoperatively. Radiographs at 1 month and 6 months revealed the maintenance of reduction. There were no complications. According to the results of our series of patients, demanding cases of acute AC joint dislocation Rockwood type V, in professional athletes, require anatomic fixation of both coracoclavicular and AC ligaments for return to sports as soon as possible and at the preinjury level of performance. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  8. Coracoid bypass procedure: surgical technique for coracoclavicular reconstruction with coracoid insufficiency.

    PubMed

    Virk, Mandeep S; Lederman, Evan; Stevens, Christopher; Romeo, Anthony A

    2017-04-01

    Failed acromioclavicular (AC) joint reconstruction secondary to a coracoid fracture or insufficiency of the coracoid is an uncommon but challenging clinical situation. We describe a surgical technique of revision coracoclavicular (CC) reconstruction, the coracoid bypass procedure, and report short-term results with this technique in 3 patients. In the coracoid bypass procedure, reconstruction of the CC ligaments is performed by passing a tendon graft through a surgically created bone tunnel in the scapular body (inferior to the base of the coracoid) and then fixing the graft around the clavicle or through bone tunnels in the clavicle. Three patients treated with this technique were retrospectively reviewed. AC joint reconstruction performed for a traumatic AC joint separation failed in the 3 patients reported in this series. The previous procedures were an anatomic CC reconstruction in 2 patients and a modified Weaver-Dunn procedure in 1 patient. The coracoid fractures were detected postoperatively, and the mean interval from the index surgery to the coracoid bypass procedure was 8 months. The patients were a mean age of 44 years, and average follow-up was 21 months. At the last follow-up, all 3 patients were pain free, with full range of shoulder motion, preserved CC distance, and a stable AC joint. The coracoid bypass procedure is a treatment option for CC joint reconstruction during revision AC joint surgery in the setting of a coracoid fracture or coracoid insufficiency. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  9. Joint reconstruction of multiview compressed images.

    PubMed

    Thirumalai, Vijayaraghavan; Frossard, Pascal

    2013-05-01

    Distributed representation of correlated multiview images is an important problem that arises in vision sensor networks. This paper concentrates on the joint reconstruction problem where the distributively compressed images are decoded together in order to take benefit from the image correlation. We consider a scenario where the images captured at different viewpoints are encoded independently using common coding solutions (e.g., JPEG) with a balanced rate distribution among different cameras. A central decoder first estimates the inter-view image correlation from the independently compressed data. The joint reconstruction is then cast as a constrained convex optimization problem that reconstructs total-variation (TV) smooth images, which comply with the estimated correlation model. At the same time, we add constraints that force the reconstructed images to be as close as possible to their compressed versions. We show through experiments that the proposed joint reconstruction scheme outperforms independent reconstruction in terms of image quality, for a given target bit rate. In addition, the decoding performance of our algorithm compares advantageously to state-of-the-art distributed coding schemes based on motion learning and on the DISCOVER algorithm.

  10. Radiographic failure and rates of re-operation after acromioclavicular joint reconstruction: a comparison of surgical techniques.

    PubMed

    Spencer, H T; Hsu, L; Sodl, J; Arianjam, A; Yian, E H

    2016-04-01

    To compare radiographic failure and re-operation rates of anatomical coracoclavicular (CC) ligament reconstructional techniques with non-anatomical techniques after chronic high grade acromioclavicular (AC) joint injuries. We reviewed chronic AC joint reconstructions within a region-wide healthcare system to identify surgical technique, complications, radiographic failure and re-operations. Procedures fell into four categories: (1) modified Weaver-Dunn, (2) allograft fixed through coracoid and clavicular tunnels, (3) allograft loop coracoclavicular fixation, and (4) combined allograft loop and synthetic cortical button fixation. Among 167 patients (mean age 38.1 years, (standard deviation (sd) 14.7) treated at least a four week interval after injury, 154 had post-operative radiographs available for analysis. Radiographic failure occurred in 33/154 cases (21.4%), with the lowest rate in Technique 4 (2/42 4.8%, p = 0.001). Half the failures occurred by six weeks, and the Kaplan-Meier survivorship at 24 months was 94.4% (95% confidence interval (CI) 79.6 to 98.6) for Technique 4 and 69.9% (95% CI 59.4 to 78.3) for the other techniques when combined. In multivariable survival analysis, Technique 4 had better survival than other techniques (Hazard Ratio 0.162, 95% CI 0.039 to 0.068, p = 0.013). Among 155 patients with a minimum of six months post-operative insurance coverage, re-operation occurred in 9.7% (15 patients). However, in multivariable logistic regression, Technique 4 did not reach a statistically significant lower risk for re-operation (odds ratio 0.254, 95% CI 0.05 to 1.3, p = 0.11). In this retrospective series, anatomical CC ligament reconstruction using combined synthetic cortical button and allograft loop fixation had the lowest rate of radiographic failure. Anatomical coracoclavicular ligament reconstruction using combined synthetic cortical button and allograft loop fixation had the lowest rate of radiographic failure. ©2016 The British Editorial

  11. Electromigration analysis of solder joints under ac load: A mean time to failure model

    NASA Astrophysics Data System (ADS)

    Yao, Wei; Basaran, Cemal

    2012-03-01

    In this study, alternating current (ac) electromigration (EM) degradation simulations were carried out for Sn95.5%Ag4.0%Cu0.5 (SAC405- by weight) solder joints. Mass transport analysis was conducted with viscoplastic material properties for quantifying damage mechanism in solder joints. Square, sine, and triangle current wave forms ac were used as input signals. dc and pulsed dc (PDC) electromigration analysis were conducted for comparison purposes. The maximum current density ranged from 2.2×106A/cm2 to 5.0×106A/cm2, frequency ranged from 0.05 Hz to 5 Hz with ambient temperature varying from 350 K to 450 K. Because the room temperature is nearly two-thirds of SAC solder joint's melting point on absolute temperature scale (494.15 K), viscoplastic material model is essential. Entropy based damage evolution model was used to investigate mean time to failure (MTF) behavior of solder joints subjected to ac stressing. It was observed that MTF was inversely proportional to ambient temperature T1.1 in Celsius and also inversely proportional to current density j0.27 in A/cm2. Higher frequency will lead to a shorter lifetime with in the frequency range we studied, and a relationship is proposed as MTF∝f-0.41. Lifetime of a solder joint subjected to ac is longer compared with dc and PDC loading conditions. By introducing frequency, ambient temperature and current density dependency terms, a modified MTTF equation was proposed for solder joints subjected to ac current stressing.

  12. [Application of joint reconstruction with autogenous coronoid process graft to treat temporomandibular joint ankylosis].

    PubMed

    Xie, Qing-tiao; Huang, Xuan-ping; Jiang, Xian-fang; Yang, Yuan-yuan; Li, Hua; Lin, Xi

    2013-08-01

    To evaluate the clinical effect of joint reconstruction by using autogenous coronoid process graft to treat temporomandibular joint(TMJ) ankylosis. Nine cases of TMJ ankylosis from September 2008 to September 2010 were surgically treated by joint reconstruction with autogenous coronoid process graft, using autogenous articular disc or prosthodontic membrane as interpositional material. Mouth opening, occlusion and cone beam CT(CBCT) were used for evaluation before and after surgery. Satisfactory mouth opening was achieved in all patients and no one got occlusal changes or reankylosis during follow-up. CBCT showed that coronoid process graft reached bone union with the ramus and turned to be round. It is effective to cure TMJ ankylosis through joint reconstruction with autogenous coronoid process graft.

  13. Biomechanical evaluation of a novel reverse coracoacromial ligament reconstruction for acromioclavicular joint separation.

    PubMed

    Shu, Beatrice; Johnston, Tyler; Lindsey, Derek P; McAdams, Timothy R

    2012-02-01

    Enhancing anterior-posterior (AP) stability in acromioclavicular (AC) reconstruction may be advantageous. To compare the initial stability of AC reconstructions with and without augmentation by either (1) a novel "reverse" coracoacromial (CA) ligament transfer or (2) an intramedullary AC tendon graft. Reverse CA transfer will improve AP stability compared with isolated coracoclavicular (CC) reconstruction. Controlled laboratory study. Six matched pairs of cadaveric shoulders underwent distal clavicle resection and CC reconstruction. Displacement (mm) was measured during cyclic loading along AP (±25 N) and superior-inferior (SI; 10-N compression, 70-N tension) axes. Pairs were randomized to receive each augmentation and the same loading protocol applied. Reverse CA transfer (3.71 ± 1.3 mm, standard error of the mean [SEM]; P = .03) and intramedullary graft (3.41 ± 1.1 mm; P = .03) decreased AP translation compared with CC reconstruction alone. The SI displacement did not differ. Equivalence tests suggest no difference between augmentations in AP or SI restraint. Addition of either reverse CA transfer or intramedullary graft demonstrates improved AP restraint and provides similar SI stability compared with isolated CC reconstruction. Reverse CA ligament transfer may be a reasonable alternative to a free tendon graft to augment AP restraint in AC reconstruction.

  14. Surgical treatment of acute acromioclavicular joint dislocations: hook plate versus minimally invasive reconstruction.

    PubMed

    Metzlaff, S; Rosslenbroich, S; Forkel, P H; Schliemann, B; Arshad, H; Raschke, M; Petersen, W

    2016-06-01

    This study was performed to compare the clinical results of a minimally invasive technique for acute acromioclavicular (AC) joint dislocation repair with the traditional hook plate fixation. Forty-four patients with an acute (within 2 weeks after trauma) complete AC joint separation (35 male, nine female; median age 36.2 years, range 18-56) underwent surgical repair with either a minimally invasive AC joint repair or a conventional hook plate. Functional outcome was evaluated using the Constant-Murley Score (CMS), the TAFT score and the AC joint instability score (ACJI). Radiographic evaluation was performed with bilateral anterior-posterior (a.p.) stress and Alexander views. All patients were available after a median follow-up of 32 months (range 24-51). There were no significant differences in the mean CMS, Taft score and the ACJI between the two groups. The radiological assessment revealed no significant difference in the coracoclavicular distance. In both groups, a slight loss of reduction was observed. Periarticular ossification was seen in 11 patients of the minimally invasive AC joint repair and eight patients of the hook plate group but this did not affect the final outcome. Hook plates were removed after a median interval of 11.9 weeks (range 10-13). Good clinical results can be achieved with both minimally invasive AC joint repair and hook plate fixation. However, in the hook plate group a second operation is mandatory for plate removal. III.

  15. Arthroscopic fixation of acute acromioclavicular joint disruption with TightRope™: Outcome and complications after minimum 2 (2-5) years follow-up.

    PubMed

    Zhang, Li-Feng; Yin, Bo; Hou, Su; Han, Bing; Huang, De-Fa

    2017-01-01

    To evaluate the midterm results of arthroscopic reconstruction of acute acromioclavicular (AC) joint disruption using TightRope™ system. We retrospectively assess the results of 24 patients of acute AC joint dislocation who were operated using TightRope system. Constant and University of California, Los Angeles (UCLA) scores and coracoclavicular distance were calculated pre- and postoperatively. Data was entered into MS excel and analyzed using the SPSS version 17. The mean follow-up was 39.45 months. Constant and UCLA scores were significantly increased postoperatively. Six patients had partial loss of reduction within 3-6 months and two patients had a failure of construct. Constant score was significantly lower in these patients. TightRope reconstruction of the AC joint is a reproducible and safe alternative to many other techniques of AC joint reconstruction. Early subluxation remains a concern and may reflect the need for technique modification.

  16. Arthroscopically assisted acromioclavicular joint reconstruction.

    PubMed

    Baumgarten, Keith M; Altchek, David W; Cordasco, Frank A

    2006-02-01

    Arthroscopically assisted acromioclavicular joint reconstruction avoids the large incisions necessary with open reconstructions. This acromioclavicular joint reconstruction technique via the subacromial space does not violate the rotator interval or require screw removal. The patient is placed in a modified beach-chair position. The arthroscope is placed into the subacromial space, and a bursectomy is performed through a lateral subacromial portal. The coracoacromial ligament is released from the acromion with an electrocautery and an arthroscopic elevator. A nonabsorbable suture is passed through the coracoacromial ligament with a suture passer, and an arthroscopic suture grasper is used to deliver both ends of the suture out through the lateral portal. The coracoid is identified and isolated using a radiofrequency ablator placed through the anterior portal while visualizing through the lateral portal. A percutaneous shuttle device is passed through the skin superomedial to the coracoid. The shuttle is visualized entering superior to the coracoid and is passed just medial to the coracoid. Once the tip of the shuttle can be visualized in the recess inferior to the coracoid, the shuttle loop is advanced. A suture grasper is used to deliver both ends of the shuttle out through the anterior portal. A semitendinosus allograft is used to reconstruct the coracoclavicular ligament. A nonabsorbable suture is passed through both ends of the allograft. Three strands of nonabsorbable suture are braided together. The tendon and the braided suture are shuttled around the coracoid. At this point, both the braided suture and the allograft tendon enter the anterior portal, wrap around the coracoid base, and exit the anterior portal. A 3-cm incision is made over the distal clavicle. A hole is drilled through the clavicle with a 5-mm drill. A loop of 22-gauge wire is passed through the hole in the clavicle, and a looped suture is shuttled through the hole. A curved clamp is used to

  17. Joint reconstruction of PET-MRI by exploiting structural similarity

    NASA Astrophysics Data System (ADS)

    Ehrhardt, Matthias J.; Thielemans, Kris; Pizarro, Luis; Atkinson, David; Ourselin, Sébastien; Hutton, Brian F.; Arridge, Simon R.

    2015-01-01

    Recent advances in technology have enabled the combination of positron emission tomography (PET) with magnetic resonance imaging (MRI). These PET-MRI scanners simultaneously acquire functional PET and anatomical or functional MRI data. As function and anatomy are not independent of one another the images to be reconstructed are likely to have shared structures. We aim to exploit this inherent structural similarity by reconstructing from both modalities in a joint reconstruction framework. The structural similarity between two modalities can be modelled in two different ways: edges are more likely to be at similar positions and/or to have similar orientations. We analyse the diffusion process generated by minimizing priors that encapsulate these different models. It turns out that the class of parallel level set priors always corresponds to anisotropic diffusion which is sometimes forward and sometimes backward diffusion. We perform numerical experiments where we jointly reconstruct from blurred Radon data with Poisson noise (PET) and under-sampled Fourier data with Gaussian noise (MRI). Our results show that both modalities benefit from each other in areas of shared edge information. The joint reconstructions have less artefacts and sharper edges compared to separate reconstructions and the ℓ2-error can be reduced in all of the considered cases of under-sampling.

  18. Joint sparse reconstruction of multi-contrast MRI images with graph based redundant wavelet transform.

    PubMed

    Lai, Zongying; Zhang, Xinlin; Guo, Di; Du, Xiaofeng; Yang, Yonggui; Guo, Gang; Chen, Zhong; Qu, Xiaobo

    2018-05-03

    Multi-contrast images in magnetic resonance imaging (MRI) provide abundant contrast information reflecting the characteristics of the internal tissues of human bodies, and thus have been widely utilized in clinical diagnosis. However, long acquisition time limits the application of multi-contrast MRI. One efficient way to accelerate data acquisition is to under-sample the k-space data and then reconstruct images with sparsity constraint. However, images are compromised at high acceleration factor if images are reconstructed individually. We aim to improve the images with a jointly sparse reconstruction and Graph-based redundant wavelet transform (GBRWT). First, a sparsifying transform, GBRWT, is trained to reflect the similarity of tissue structures in multi-contrast images. Second, joint multi-contrast image reconstruction is formulated as a ℓ 2, 1 norm optimization problem under GBRWT representations. Third, the optimization problem is numerically solved using a derived alternating direction method. Experimental results in synthetic and in vivo MRI data demonstrate that the proposed joint reconstruction method can achieve lower reconstruction errors and better preserve image structures than the compared joint reconstruction methods. Besides, the proposed method outperforms single image reconstruction with joint sparsity constraint of multi-contrast images. The proposed method explores the joint sparsity of multi-contrast MRI images under graph-based redundant wavelet transform and realizes joint sparse reconstruction of multi-contrast images. Experiment demonstrate that the proposed method outperforms the compared joint reconstruction methods as well as individual reconstructions. With this high quality image reconstruction method, it is possible to achieve the high acceleration factors by exploring the complementary information provided by multi-contrast MRI.

  19. Customizing Extensor Reconstruction in Vascularized Toe Joint Transfers to Finger Proximal Interphalangeal Joints: A Strategic Approach for Correcting Extensor Lag.

    PubMed

    Loh, Charles Yuen Yung; Hsu, Chung-Chen; Lin, Cheng-Hung; Chen, Shih-Heng; Lien, Shwu-Huei; Lin, Chih-Hung; Wei, Fu-Chan; Lin, Yu-Te

    2017-04-01

    Vascularized toe proximal interphalangeal joint transfer allows the restoration of damaged joints. However, extensor lag and poor arc of motion have been reported. The authors present their outcomes of treatment according to a novel reconstructive algorithm that addresses extensor lag and allows for consistent results postoperatively. Vascularized toe joint transfers were performed in a consecutive series of 26 digits in 25 patients. The average age was 30.5 years, with 14 right and 12 left hands. Reconstructed digits included eight index, 10 middle, and eight ring fingers. Simultaneous extensor reconstructions were performed and eight were centralization of lateral bands, five were direct extensor digitorum longus-to-extensor digitorum communis repairs, and 13 were central slip reconstructions. The average length of follow-up was 16.7 months. The average extension lag was 17.9 degrees. The arc of motion was 57.7 degrees (81.7 percent functional use of pretransfer toe proximal interphalangeal joint arc of motion). There was no significant difference in the reconstructed proximal interphalangeal joint arc of motion for the handedness (p = 0.23), recipient digits (p = 0.37), or surgical experience in vascularized toe joint transfer (p = 0.25). The outcomes of different techniques of extensor mechanism reconstruction were similar in terms of extensor lag, arc of motion, and reconstructed finger arc of motion compared with the pretransfer toe proximal interphalangeal joint arc of motion. With this treatment algorithm, consistent outcomes can be produced with minimal extensor lag and maximum use of potential toe proximal interphalangeal joint arc of motion. Therapeutic, IV.

  20. Comparison of hook plate with versus without double-tunnel coracoclavicular ligament reconstruction for repair of acute acromioclavicular joint dislocations: A prospective randomized controlled clinical trial.

    PubMed

    Yin, Jian; Yin, Zhaoyang; Gong, Ge; Zhu, Chao; Sun, Chao; Liu, Xinhui

    2018-06-01

    This study was designed to compare the surgical outcomes of a hook plate with double-tunnel coracoclavicular (CC) ligament reconstruction by conjoined tendon transfer versus single hook plate surgery for the repair of acute type of Rockwood type III and V acromioclavicular (AC) joint dislocations. The study cohort included 62 patients with acute (within 6 weeks after trauma) Rockwood type III and V AC joint dislocations who underwent surgery from February 2012 to September 2015. The patients were randomly allocated to the ligament reconstruction group (LR group, n = 31) or the single hook plate group (HP group, n = 31). In both groups, reduction of the AC joint by hook plate and repair of the ruptured AC ligament with absorbable Vicryl sutures were performed homoplastically. The lateral half of the short tendon of the biceps brachii muscle and the lateral half of the flexor tendon were used to reconstruct the trapezoid and conoid ligaments, respectively. Differences in surgical duration, intraoperative blood loss, incision length, and total cost were compared between the two groups. Furthermore, the preoperative and postoperative visual analogue score (VAS), postoperative American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score (CMS), Karlsson score, complication rates, and patient satisfaction at the last follow-up were compared to evaluate the curative effects of the surgical treatments. Magnetic resonance imaging (MRI) after hook plate removal was used to evaluate the reconstructed ligaments and tendon-bone interface. In total, 25 patients in the LR group and 26 in the HP group completed the follow-up. There were no statistically significant differences in age, sex, Rockwood type, placing time, total cost, and follow-up duration between the LR and HP groups (p > 0.05). However, as compared with the HP group, the surgical duration and incision length were longer in the LR group (92.08 ± 19.25 vs. 56.54 ± 21.29 min and 13

  1. Reconstructive surgery for patellofemoral joint incongruency.

    PubMed

    Neumann, M V; Stalder, M; Schuster, A J

    2016-03-01

    A retrospective analysis of a heterogeneous patient cohort was performed to determine the outcome and eligibility of a combined trochleaplasty and soft tissue-balancing technique for repair of patellofemoral joint disorders. A strict surgical treatment algorithm including trochleaplasty and reconstruction of the medial patellofemoral ligament and vastus medialis oblique muscle was implemented to restore the patellofemoral joint. A heterogeneous patient cohort including 46 consecutively treated symptomatic knees was reviewed. The median follow-up period was 4.7 years (range 24-109 months). No patellar redislocation occurred post-operatively, and the median Kujala score improved from 62 (9-96) to 88 (47-100) points (p < 0.001) at follow-up. Radiological signs of trochlear dysplasia were corrected, and both patellar height and trochlear depth were significantly restored after surgery. In total, 16% of affected patients with pre-existing patellofemoral degenerative changes showed progression of osteoarthrosis according to the Kellgren and Lawrence classification. The surgical combination of trochleaplasty and reconstruction of the medial patellofemoral ligament and vastus medialis oblique muscle offers excellent clinical and radiological results. The overall results of the present study showed significant improvement of the Kujala score in patients with Dejour grades C and D dysplasia. These results outline the clinical relevance of trochleaplasty with additional soft tissue balancing as an effective joint-preserving method with satisfying results in patients with pre-existing degenerative changes. IV.

  2. Immediate effects of neuromuscular joint facilitation intervention after anterior cruciate ligament reconstruction.

    PubMed

    Wang, Lei

    2016-07-01

    [Purpose] The aim of this study was to examine the immediate effects of neuromuscular joint facilitation (NJF) on the functional activity level after rehabilitation of anterior cruciate ligament (ACL) reconstruction. [Subjects and Methods] Ten young subjects (8 males and 2 females) who underwent ACL reconstruction were included in the study. The subjects were divided into two groups, namely, knee joint extension muscle strength training (MST) group and knee joint extension outside rotation pattern of NJF group. Extension strength was measured in both groups before and after the experiment. Surface electromyography (sEMG) of the vastus medialis and vastus lateralis muscles and joint position error (JPE) test of the knee joint were also conducted. [Results] JPE test results and extension strength measurements in the NJF group were improved compared with those in the MST group. Moreover, the average discharge of the vastus medialis and vastus lateralis muscles on sEMG in the NJF group was significantly increased after MST and NJF treatments. [Conclusion] The obtained results suggest that NJF training in patients with ACL reconstruction can improve knee proprioception ability and muscle strength.

  3. Joint reconstruction of activity and attenuation in Time-of-Flight PET: A Quantitative Analysis.

    PubMed

    Rezaei, Ahmadreza; Deroose, Christophe M; Vahle, Thomas; Boada, Fernando; Nuyts, Johan

    2018-03-01

    Joint activity and attenuation reconstruction methods from time of flight (TOF) positron emission tomography (PET) data provide an effective solution to attenuation correction when no (or incomplete/inaccurate) information on the attenuation is available. One of the main barriers limiting their use in clinical practice is the lack of validation of these methods on a relatively large patient database. In this contribution, we aim at validating the activity reconstructions of the maximum likelihood activity reconstruction and attenuation registration (MLRR) algorithm on a whole-body patient data set. Furthermore, a partial validation (since the scale problem of the algorithm is avoided for now) of the maximum likelihood activity and attenuation reconstruction (MLAA) algorithm is also provided. We present a quantitative comparison of the joint reconstructions to the current clinical gold-standard maximum likelihood expectation maximization (MLEM) reconstruction with CT-based attenuation correction. Methods: The whole-body TOF-PET emission data of each patient data set is processed as a whole to reconstruct an activity volume covering all the acquired bed positions, which helps to reduce the problem of a scale per bed position in MLAA to a global scale for the entire activity volume. Three reconstruction algorithms are used: MLEM, MLRR and MLAA. A maximum likelihood (ML) scaling of the single scatter simulation (SSS) estimate to the emission data is used for scatter correction. The reconstruction results are then analyzed in different regions of interest. Results: The joint reconstructions of the whole-body patient data set provide better quantification in case of PET and CT misalignments caused by patient and organ motion. Our quantitative analysis shows a difference of -4.2% (±2.3%) and -7.5% (±4.6%) between the joint reconstructions of MLRR and MLAA compared to MLEM, averaged over all regions of interest, respectively. Conclusion: Joint activity and attenuation

  4. Complete acromioclavicular joint dislocation treated with reconstructed ligament by trapezius muscle fascia and observation of fascial metaplasia.

    PubMed

    Wang, Chaoliang; Huang, Sufang; Wang, Yingzhen; Sun, Xuesheng; Zhu, Tao; Li, Qiang; Lin, Chu

    2015-01-01

    We evaluated the long-term clinical results of acute complete acromioclavicular dislocations treated by reconstruction of the acromioclavicular and coracoclavicular ligament using trapezius muscle fascia. Open reduction and internal fixation was performed using the clavicular hook plate in 12 patients with acute complete acromioclavicular joint dislocation, and the acromioclavicular and coracoclavicular ligaments were reconstructed using trapezius muscle fascia. Radiographic evaluations were conducted postoperatively. We evaluated the functional results with constant scoring system and radiological results at the final follow-up visit. The mean Constant score at the final follow-up visit was 91.67 (range, 81 to 100). The results were excellent in eight patients (66.7%) and good in four patients (33.3%). Three patients with scores from 80 to 90 had mild pain during activity, but this did not affect the range of motion of the shoulder. All patients have returned to their preoperative work without any limitations. Compared with the contralateral side, radiography showed anatomical reposition in the vertical plane in all cases. The hook-plate fixation with ligament reconstruction was successful in treating AC dislocations. The acromioclavicular and coracoclavicular ligament were reconstructed by trapezius muscle fascia that keep the distal clavicle stable both vertically and horizontally after type III injuries.

  5. Complete acromioclavicular joint dislocation treated with reconstructed ligament by trapezius muscle fascia and observation of fascial metaplasia

    PubMed Central

    Wang, Chaoliang; Huang, Sufang; Wang, Yingzhen; Sun, Xuesheng; Zhu, Tao; Li, Qiang; Lin, Chu

    2015-01-01

    We evaluated the long-term clinical results of acute complete acromioclavicular dislocations treated by reconstruction of the acromioclavicular and coracoclavicular ligament using trapezius muscle fascia. Open reduction and internal fixation was performed using the clavicular hook plate in 12 patients with acute complete acromioclavicular joint dislocation, and the acromioclavicular and coracoclavicular ligaments were reconstructed using trapezius muscle fascia. Radiographic evaluations were conducted postoperatively. We evaluated the functional results with constant scoring system and radiological results at the final follow-up visit. The mean Constant score at the final follow-up visit was 91.67 (range, 81 to 100). The results were excellent in eight patients (66.7%) and good in four patients (33.3%). Three patients with scores from 80 to 90 had mild pain during activity, but this did not affect the range of motion of the shoulder. All patients have returned to their preoperative work without any limitations. Compared with the contralateral side, radiography showed anatomical reposition in the vertical plane in all cases. The hook-plate fixation with ligament reconstruction was successful in treating AC dislocations. The acromioclavicular and coracoclavicular ligament were reconstructed by trapezius muscle fascia that keep the distal clavicle stable both vertically and horizontally after type III injuries. PMID:28352721

  6. Morphology and Mobility of the Reconstructed Basilar Joint of the Pollicized Index Finger.

    PubMed

    Strugarek-Lecoanet, Clotilde; Chevrollier, Jérémie; Pauchard, Nicolas; Blum, Alain; Dap, François; Dautel, Gilles

    2016-09-01

    To evaluate outcome and function of the reconstructed basilar thumb joint after index finger pollicization in patients presenting congenital thumb deficiency. Plain radiographs and 4-dimensional dynamic volume computed tomography scan were used to evaluate the outcome of 23 pollicizations performed on 14 children between 1996 and 2009. The mean follow-up was 8 years. Patients performed continuous movements of thumb opposition during the imaging studies. Four-dimensional scan images made it possible to visualize mobility within the reconstructed joint. In 14 cases, union occurred in the metacarpal head/metacarpal base interface. In the 9 other cases, there was a nonunion at this interface. The reconstructed joint was mobile in 20 cases, including 3 in which there was also mobility at the site of the nonunion. In 3 cases in our series, mobility was present only at the site of the nonunion, between the base and the head of the second metacarpal. Remodeling and flattening out of the metacarpal head occurred in 16 of 23 cases. The transposed metacarpal head remained spherical in 7 cases. The reconstructed joint adapts, both morphologically and functionally, allowing movement on all 3 spatial planes. Existing mechanical constraints on the reconstructed joint may explain its remodeled appearance. Therapeutic IV. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  7. Rotationplasty with vascular reconstruction for prosthetic knee joint infection.

    PubMed

    Fujiki, Masahide; Miyamoto, Shimpei; Nakatani, Fumihiko; Kawai, Akira; Sakuraba, Minoru

    2015-01-01

    Rotationplasty is used most often as a function-preserving salvage procedure after resection of sarcomas of the lower extremity; however, it is also used after infection of prosthetic knee joints. Conventional vascular management during rotationplasty is to preserve and coil major vessels, but recently, transection and reanastomosis of the major vessels has been widely performed. However, there has been little discussion regarding the optimal vascular management of rotationplasty after infection of prosthetic knee joints because rotationplasty is rarely performed for this indication. We reviewed four patients who had undergone resection of osteosarcomas of the femur, placement of a prosthetic knee joint, and rotationplasty with vascular reconstruction from 2010 to 2013. The mean interval between prosthetic joint replacement and rotationplasty was 10.4 years and the mean interval between the diagnosis of prosthesis infection and rotationplasty was 7.9 years. Rotationplasty was successful in all patients; however, in one patient, arterial thrombosis developed and necessitated urgent surgical removal and arterial reconstruction. All patients were able to walk independently with a prosthetic limb after rehabilitation. Although there is no consensus regarding the most appropriate method of vascular management during rotationplasty for revision of infected prosthetic joints, vascular transection and reanastomosis is a useful option.

  8. Joint reconstruction via coupled Bregman iterations with applications to PET-MR imaging

    NASA Astrophysics Data System (ADS)

    Rasch, Julian; Brinkmann, Eva-Maria; Burger, Martin

    2018-01-01

    Joint reconstruction has recently attracted a lot of attention, especially in the field of medical multi-modality imaging such as PET-MRI. Most of the developed methods rely on the comparison of image gradients, or more precisely their location, direction and magnitude, to make use of structural similarities between the images. A challenge and still an open issue for most of the methods is to handle images in entirely different scales, i.e. different magnitudes of gradients that cannot be dealt with by a global scaling of the data. We propose the use of generalized Bregman distances and infimal convolutions thereof with regard to the well-known total variation functional. The use of a total variation subgradient respectively the involved vector field rather than an image gradient naturally excludes the magnitudes of gradients, which in particular solves the scaling behavior. Additionally, the presented method features a weighting that allows to control the amount of interaction between channels. We give insights into the general behavior of the method, before we further tailor it to a particular application, namely PET-MRI joint reconstruction. To do so, we compute joint reconstruction results from blurry Poisson data for PET and undersampled Fourier data from MRI and show that we can gain a mutual benefit for both modalities. In particular, the results are superior to the respective separate reconstructions and other joint reconstruction methods.

  9. Comparative evaluation between anatomic and non-anatomic lateral ligament reconstruction techniques in the ankle joint: A computational study.

    PubMed

    Purevsuren, Tserenchimed; Batbaatar, Myagmarbayar; Khuyagbaatar, Batbayar; Kim, Kyungsoo; Kim, Yoon Hyuk

    2018-03-12

    Biomechanical studies have indicated that the conventional non-anatomic reconstruction techniques for lateral ankle sprain (LAS) tend to restrict subtalar joint motion compared to intact ankle joints. Excessive restriction in subtalar motion may lead to chronic pain, functional difficulties, and development of osteoarthritis. Therefore, various anatomic surgical techniques to reconstruct both the anterior talofibular and calcaneofibular ligaments have been introduced. In this study, ankle joint stability was evaluated using multibody computational ankle joint model to assess two new anatomic reconstruction and three popular non-anatomic reconstruction techniques. An LAS injury, three popular non-anatomic reconstruction models (Watson-Jones, Evans, and Chrisman-Snook), and two common types of anatomic reconstruction models were developed based on the intact ankle model. The stability of ankle in both talocrural and subtalar joint were evaluated under anterior drawer test (150 N anterior force), inversion test (3 Nm inversion moment), internal rotational test (3 Nm internal rotation moment), and the combined loading test (9 Nm inversion and internal moment as well as 1800 N compressive force). Our overall results show that the two anatomic reconstruction techniques were superior to the non-anatomic reconstruction techniques in stabilizing both talocrural and subtalar joints. Restricted subtalar joint motion, which mainly observed in Watson-Jones and Chrisman-Snook techniques, was not shown in the anatomical reconstructions. Evans technique was beneficial for subtalar joint as it does not restrict subtalar motion, though Evans technique was insufficient for restoring talocrural joint inversion. The anatomical reconstruction techniques best recovered ankle stability.

  10. Towards disparity joint upsampling for robust stereoscopic endoscopic scene reconstruction in robotic prostatectomy

    NASA Astrophysics Data System (ADS)

    Luo, Xiongbiao; McLeod, A. Jonathan; Jayarathne, Uditha L.; Pautler, Stephen E.; Schlacta, Christopher M.; Peters, Terry M.

    2016-03-01

    Three-dimensional (3-D) scene reconstruction from stereoscopic binocular laparoscopic videos is an effective way to expand the limited surgical field and augment the structure visualization of the organ being operated in minimally invasive surgery. However, currently available reconstruction approaches are limited by image noise, occlusions, textureless and blurred structures. In particular, an endoscope inside the body only has the limited light source resulting in illumination non-uniformities in the visualized field. These limitations unavoidably deteriorate the stereo image quality and hence lead to low-resolution and inaccurate disparity maps, resulting in blurred edge structures in 3-D scene reconstruction. This paper proposes an improved stereo correspondence framework that integrates cost-volume filtering with joint upsampling for robust disparity estimation. Joint bilateral upsampling, joint geodesic upsampling, and tree filtering upsampling were compared to enhance the disparity accuracy. The experimental results demonstrate that joint upsampling provides an effective way to boost the disparity estimation and hence to improve the surgical endoscopic scene 3-D reconstruction. Moreover, the bilateral upsampling generally outperforms the other two upsampling methods in disparity estimation.

  11. Three-dimensional reconstruction of rat knee joint using episcopic fluorescence image capture.

    PubMed

    Takaishi, R; Aoyama, T; Zhang, X; Higuchi, S; Yamada, S; Takakuwa, T

    2014-10-01

    Development of the knee joint was morphologically investigated, and the process of cavitation was analyzed by using episcopic fluorescence image capture (EFIC) to create spatial and temporal three-dimensional (3D) reconstructions. Knee joints of Wister rat embryos between embryonic day (E)14 and E20 were investigated. Samples were sectioned and visualized using an EFIC. Then, two-dimensional image stacks were reconstructed using OsiriX software, and 3D reconstructions were generated using Amira software. Cavitations of the knee joint were constructed from five divided portions. Cavity formation initiated at multiple sites at E17; among them, the femoropatellar cavity (FPC) was the first. Cavitations of the medial side preceded those of the lateral side. Each cavity connected at E20 when cavitations around the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) were completed. Cavity formation initiated from six portions. In each portion, development proceeded asymmetrically. These results concerning anatomical development of the knee joint using EFIC contribute to a better understanding of the structural feature of the knee joint. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  12. The Effectiveness of a Functional Knee Brace on Joint-Position Sense in Anterior Cruciate Ligament-Reconstructed Individuals.

    PubMed

    Sugimoto, Dai; LeBlanc, Jessica C; Wooley, Sarah E; Micheli, Lyle J; Kramer, Dennis E

    2016-05-01

    It is estimated that approximately 350,000 individuals undergo anterior cruciate ligament (ACL) reconstruction surgery in each year in the US. Although ACL-reconstruction surgery and postoperative rehabilitation are successfully completed, deficits in postural control remain prevalent in ACL-reconstructed individuals. In order to assist the lack of balance ability and reduce the risk of retear of the reconstructed ACL, physicians often provide a functional knee brace on the patients' return to physical activity. However, it is not known whether use of the functional knee brace enhances knee-joint position sense in individuals with ACL reconstruction. Thus, the effect of a functional knee brace on knee-joint position sense in an ACL-reconstructed population needs be critically appraised. After systematically review of previously published literature, 3 studies that investigated the effect of a functional knee brace in ACL-reconstructed individuals using joint-position-sense measures were found. They were rated as level 2b evidence in the Centre of Evidence Based Medicine Level of Evidence chart. Synthesis of the reviewed studies indicated inconsistent evidence of a functional knee brace on joint-position improvement after ACL reconstruction. More research is needed to provide sufficient evidence on the effect of a functional knee brace on joint-position sense after ACL reconstruction. Future studies need to measure joint-position sense in closed-kinetic-chain fashion since ACL injury usually occurs under weight-bearing conditions.

  13. Brief report: reconstruction of joint hyaline cartilage by autologous progenitor cells derived from ear elastic cartilage.

    PubMed

    Mizuno, Mitsuru; Kobayashi, Shinji; Takebe, Takanori; Kan, Hiroomi; Yabuki, Yuichiro; Matsuzaki, Takahisa; Yoshikawa, Hiroshi Y; Nakabayashi, Seiichiro; Ik, Lee Jeong; Maegawa, Jiro; Taniguchi, Hideki

    2014-03-01

    In healthy joints, hyaline cartilage covering the joint surfaces of bones provides cushioning due to its unique mechanical properties. However, because of its limited regenerative capacity, age- and sports-related injuries to this tissue may lead to degenerative arthropathies, prompting researchers to investigate a variety of cell sources. We recently succeeded in isolating human cartilage progenitor cells from ear elastic cartilage. Human cartilage progenitor cells have high chondrogenic and proliferative potential to form elastic cartilage with long-term tissue maintenance. However, it is unknown whether ear-derived cartilage progenitor cells can be used to reconstruct hyaline cartilage, which has different mechanical and histological properties from elastic cartilage. In our efforts to develop foundational technologies for joint hyaline cartilage repair and reconstruction, we conducted this study to obtain an answer to this question. We created an experimental canine model of knee joint cartilage damage, transplanted ear-derived autologous cartilage progenitor cells. The reconstructed cartilage was rich in proteoglycans and showed unique histological characteristics similar to joint hyaline cartilage. In addition, mechanical properties of the reconstructed tissues were higher than those of ear cartilage and equal to those of joint hyaline cartilage. This study suggested that joint hyaline cartilage was reconstructed from ear-derived cartilage progenitor cells. It also demonstrated that ear-derived cartilage progenitor cells, which can be harvested by a minimally invasive method, would be useful for reconstructing joint hyaline cartilage in patients with degenerative arthropathies. © AlphaMed Press.

  14. [Non vascularized toe phalangeal transfers for symbrachydactyly. Active range of motion without joint reconstruction].

    PubMed

    Leca, J-B; Auquit Auckbur, I; Bachy, B; Milliez, P-Y

    2008-12-01

    Symbrachydactyly is a rare congenital malformation of the hand and its treatment is controversial. Non vascularized toe phalangeal transfers have been used for management of short digits for three children. Six phalanges have been harvested complete with their periosteum. No joint reconstruction has been performed and all children have undergone surgery at a young age. Four of six digits involved have an active range of motion (range 30 to 105 degrees ). All authors who have reported active range of motion of toe phalangeal transfers have performed joint reconstruction. Here, we report obtaining active range of motion of phalangeal transfers without necessity of joint reconstruction.

  15. Help Desk Answers: Surgery vs conservative management for AC joint repair: How do the 2 compare?

    PubMed

    Matchin, Bruce; Yee, Bruce; Mott, Timothy

    2016-04-01

    When not considering the grade of acromioclavicular (AC) joint dislocation, both conservative and surgical management lead to positive outcomes, although surgically managed patients require more time out of work.

  16. The Influence of Task Complexity on Knee Joint Kinetics Following ACL Reconstruction

    PubMed Central

    Schroeder, Megan J.; Krishnan, Chandramouli; Dhaher, Yasin Y.

    2015-01-01

    Background Previous research indicates that subjects with anterior cruciate ligament reconstruction exhibit abnormal knee joint movement patterns during functional activities like walking. While the sagittal plane mechanics have been studied extensively, less is known about the secondary planes, specifically with regard to more demanding tasks. This study explored the influence of task complexity on functional joint mechanics in the context of graft-specific surgeries. Methods In 25 participants (10 hamstring tendon graft, 6 patellar tendon graft, 9 matched controls), three-dimensional joint torques were calculated using a standard inverse dynamics approach during level walking and stair descent. The stair descent task was separated into two functionally different sub-tasks—step-to-floor and step-to-step. The differences in external knee moment profiles were compared between groups; paired differences between the reconstructed and non-reconstructed knees were also assessed. Findings The reconstructed knees, irrespective of graft type, typically exhibited significantly lower peak knee flexion moments compared to control knees during stair descent, with the differences more pronounced in the step-to-step task. Frontal plane adduction torque deficits were graft-specific and limited to the hamstring tendon knees during the step-to-step task. Internal rotation torque deficits were also primarily limited to the hamstring tendon graft group during stair descent. Collectively, these results suggest that task complexity was a primary driver of differences in joint mechanics between anterior cruciate ligament reconstructed individuals and controls, and such differences were more pronounced in individuals with hamstring tendon grafts. Interpretation The mechanical environment experienced in the cartilage during repetitive, cyclical tasks such as walking and other activities of daily living has been argued to contribute to the development of degenerative changes to the joint

  17. Direct 4D reconstruction of parametric images incorporating anato-functional joint entropy.

    PubMed

    Tang, Jing; Kuwabara, Hiroto; Wong, Dean F; Rahmim, Arman

    2010-08-07

    We developed an anatomy-guided 4D closed-form algorithm to directly reconstruct parametric images from projection data for (nearly) irreversible tracers. Conventional methods consist of individually reconstructing 2D/3D PET data, followed by graphical analysis on the sequence of reconstructed image frames. The proposed direct reconstruction approach maintains the simplicity and accuracy of the expectation-maximization (EM) algorithm by extending the system matrix to include the relation between the parametric images and the measured data. A closed-form solution was achieved using a different hidden complete-data formulation within the EM framework. Furthermore, the proposed method was extended to maximum a posterior reconstruction via incorporation of MR image information, taking the joint entropy between MR and parametric PET features as the prior. Using realistic simulated noisy [(11)C]-naltrindole PET and MR brain images/data, the quantitative performance of the proposed methods was investigated. Significant improvements in terms of noise versus bias performance were demonstrated when performing direct parametric reconstruction, and additionally upon extending the algorithm to its Bayesian counterpart using the MR-PET joint entropy measure.

  18. Arthroscopic procedures and therapeutic results of anatomical reconstruction of the coracoclavicular ligaments for acromioclavicular Joint dislocation.

    PubMed

    Takase, K; Yamamoto, K

    2016-09-01

    Surgical treatment is recommended for type 5 acromioclavicular joint dislocation on Rockwood's classification. We believe that anatomic repair of the coracoclavicular ligaments best restores the function of the acromioclavicular joint. We attempted to correctly reconstruct the anatomy of the coracoclavicular ligaments under arthroscopy, and describe the minimally invasive arthroscopic procedure. There were 22 patients; mean age at surgery, 38.1 years. Mean time to surgery was 13.2 days. Mean follow-up was 3 years 2 months. The palmaris longus tendon was excised from the ipsilateral side to replace the conoid ligament, while artificial ligament was used for reconstructing the trapezoid ligament. Both ligament reconstructions were performed arthroscopically. No temporary fixation of the acromioclavicular joint was performed. On postoperative radiographic evaluation, 4 patients showed subluxation and 2 showed dislocation of the acromioclavicular joint; the other 16 patients had maintained reduction at the final consultation. MR images 1year after surgery clearly revealed the reconstructed ligaments in 19 patients. Only 1 patient showed osteoarthritis of the acromioclavicular joint. Although it requires resection of the ipsilateral palmaris longus for grafting, we believe that anatomic reconstruction of both coracoclavicular ligaments best restores the function of the acromioclavicular joint. 4. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. Joint MR-PET reconstruction using a multi-channel image regularizer

    PubMed Central

    Koesters, Thomas; Otazo, Ricardo; Bredies, Kristian; Sodickson, Daniel K

    2016-01-01

    While current state of the art MR-PET scanners enable simultaneous MR and PET measurements, the acquired data sets are still usually reconstructed separately. We propose a new multi-modality reconstruction framework using second order Total Generalized Variation (TGV) as a dedicated multi-channel regularization functional that jointly reconstructs images from both modalities. In this way, information about the underlying anatomy is shared during the image reconstruction process while unique differences are preserved. Results from numerical simulations and in-vivo experiments using a range of accelerated MR acquisitions and different MR image contrasts demonstrate improved PET image quality, resolution, and quantitative accuracy. PMID:28055827

  20. [Clinical application of artificial condylar process for reconstructing temporomandibular joint].

    PubMed

    Huang, Xiangdao; Shao, Zhanying; Wang, Fasheng; Duan, Yi

    2012-01-01

    To assess the feasibility and clinical outcomes of artificial condylar process in reconstruction of the temporomandibular joint. Between January 2005 and January 2010, the reconstructions of the temporomandibular joints with artificial condylar process were performed in 10 cases (11 sides, including 7 left sides and 4 right sides). There were 7 males and 3 females with an average age of 50 years (range, 40-68 years). Mandibular condyle defects were caused by mandible tumor in 7 patients with a mean disease duration of 15 months (range, 9-24 months) and by bilateral condylar fractures in 3 patients with the disease duration of 2, 3, and 2 days respectively. According to Neff classification, there were type M and A in 1 case, type M and B in 1 case, and type M in one side and subcondylar fracture in the other side in 1 case. Incisions in all patients healed by first intention, and no complication occurred. All cases were followed up 1 to 4 years, showed facial symmetry and good occluding relation, and the mouth opening was 22-38 mm (mean, 30 mm). No temporomandibular joint clicking or pain and no recurrence of tumor were observed. Most of the artificial condylar process were in good position except 1 deviated from the correct angle slightly. All the patients could have diet normally. The results of temporomandibular joint reconstruction after tumor resection with artificial condylar process are good, but the clinical outcome for intracapsular condylar fracture is expected to be further verified.

  1. Reconstruction of equilibrium trajectories and joint stiffness patterns during single-joint voluntary movements under different instructions.

    PubMed

    Latash, M L

    1994-01-01

    A method for reconstructing joint compliant characteristics during voluntary movements was applied to the analysis of oscillatory and unidirectional elbow flexion movements. In different series, the subjects were given one of the following instructions: (1) do not intervene voluntarily; (2) keep the trajectory; (3) in cases of perturbations, return back to the starting position as quickly as possible (only during unidirectional movements). Under the instruction 'keep trajectory', the apparent joint stiffness increased by 50% to 250%. During oscillatory movements, this was accompanied by a decrease in the maximal difference between the actual and equilibrium joint trajectories and, in several cases, led to a change in the phase relation between the two trajectories. The coefficients of correlation between joint torque and angle were very high (commonly, over 0.9) under the 'do not intervene' instruction. They dropped to about 0.6 under the 'keep trajectory' and to about 0.3 under the 'return back' instructions. Under these two instructions, the low values of the coefficients of correlation did not allow reconstruction of segments of equilibrium trajectories and joint stiffness values in all the subjects. The results provide further support for the lambda-version of the equilibrium-point hypothesis and for using the instruction 'do not intervene voluntarily' to obtain reproducible time patterns of the central motor command.

  2. Academic productivity among fellowship associated adult total joint reconstruction surgeons.

    PubMed

    Khan, Adam Z; Kelley, Benjamin V; Patel, Ankur D; McAllister, David R; Leong, Natalie L

    2017-12-01

    The Hirsch index (h-index) is a measure that evaluates both research volume and quality-taking into consideration both publications and citations of a single author. No prior work has evaluated academic productivity and contributions to the literature of adult total joint replacement surgeons. This study uses h-index to benchmark the academic impact and identify characteristics associated with productivity of faculty members at joint replacement fellowships. Adult reconstruction fellowship programs were obtained via the American Association of Hip and Knee Surgeons website. Via the San Francisco match and program-specific websites, program characteristics (Accreditation Council for Graduate Medical Education approval, academic affiliation, region, number of fellows, fellow research requirement), associated faculty members, and faculty-specific characteristics (gender, academic title, formal fellowship training, years in practice) were obtained. H-index and total faculty publications served as primary outcome measures. Multivariable linear regression determined statistical significance. Sixty-six adult total joint reconstruction fellowship programs were identified: 30% were Accreditation Council for Graduate Medical Education approved and 73% had an academic affiliation. At these institutions, 375 adult reconstruction surgeons were identified; 98.1% were men and 85.3% had formal arthroplasty fellowship training. Average number of publications per faculty member was 50.1 (standard deviation 76.8; range 0-588); mean h-index was 12.8 (standard deviation 13.8; range 0-67). Number of fellows, faculty academic title, years in practice, and formal fellowship training had a significant ( P < .05) positive correlation with both h-index and total publications. The statistical overview presented in this work can help total joint surgeons quantitatively benchmark their academic performance against that of their peers.

  3. Joint image and motion reconstruction for PET using a B-spline motion model.

    PubMed

    Blume, Moritz; Navab, Nassir; Rafecas, Magdalena

    2012-12-21

    We present a novel joint image and motion reconstruction method for PET. The method is based on gated data and reconstructs an image together with a motion function. The motion function can be used to transform the reconstructed image to any of the input gates. All available events (from all gates) are used in the reconstruction. The presented method uses a B-spline motion model, together with a novel motion regularization procedure that does not need a regularization parameter (which is usually extremely difficult to adjust). Several image and motion grid levels are used in order to reduce the reconstruction time. In a simulation study, the presented method is compared to a recently proposed joint reconstruction method. While the presented method provides comparable reconstruction quality, it is much easier to use since no regularization parameter has to be chosen. Furthermore, since the B-spline discretization of the motion function depends on fewer parameters than a displacement field, the presented method is considerably faster and consumes less memory than its counterpart. The method is also applied to clinical data, for which a novel purely data-driven gating approach is presented.

  4. Tibiofemoral joint contact area and pressure after single- and double-bundle anterior cruciate ligament reconstruction.

    PubMed

    Morimoto, Yusuke; Ferretti, Mario; Ekdahl, Max; Smolinski, Patrick; Fu, Freddie H

    2009-01-01

    The purpose of this study was to compare the tibiofemoral contact area and pressure after single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction by use of 2 femoral and 2 tibial tunnels in intact cadaveric knees. Tibiofemoral contact area and mean and maximum pressures were measured by pressure-sensitive film (Fujifilm, Valhalla, NY) inserted between the tibia and femur. The knee was subjected to a 1,000-N axial load by use of a uniaxial testing machine at 0 degrees , 15 degrees , 30 degrees , and 45 degrees of flexion. Three conditions were evaluated: (1) intact ACL, (2) SB ACL reconstruction (n = 10 knees), and (3) DB ACL reconstruction (n = 9 knees). When compared with the intact knee, DB ACL reconstruction showed no significant difference in tibiofemoral contact area and mean and maximum pressures. SB ACL reconstruction had a significantly smaller contact area on the lateral and medial tibiofemoral joints at 30 degrees and 15 degrees of flexion. SB ACL reconstruction also had significantly higher mean pressures at 15 degrees of flexion on the medial tibiofemoral joint and at 0 degrees and 15 degrees of flexion on the lateral tibiofemoral joint, as well as significantly higher maximum pressures at 15 degrees of flexion on the lateral tibiofemoral joint. SB ACL reconstruction resulted in a significantly smaller tibiofemoral contact area and higher pressures. DB ACL more closely restores the normal contact area and pressure mainly at low flexion angles. Our findings suggest that the changes in the contact area and pressures after SB ACL reconstruction may be one of the causes of osteoarthritis on long-term follow-up. DB ACL reconstruction may reduce the incidence of osteoarthritis by closely restoring contact area and pressure.

  5. A modified surgical technique for reconstruction of an acute acromioclavicular joint dislocation

    PubMed Central

    Marchie, Anthony; Kumar, Arun; Catre, Melanio

    2009-01-01

    We report a modified surgical technique for reconstruction of coracoclavicular and acromioclavicular ligaments after acute dislocation of acromioclavicular joint using suture anchors. We have repaired 3 consecutive type III acromioclavicular dislocations with good results. This technique is simple and safe and allows anatomical reconstruction of the ligaments in acute dislocations. PMID:20671868

  6. Anatomical Evaluation of the Proximity of Neurovascular Structures During Arthroscopically Assisted Acromioclavicular Joint Reconstruction: A Cadaveric Pilot Study.

    PubMed

    Banaszek, Daniel; Pickell, Michael; Wilson, Evan; Ducsharm, Melissa; Hesse, Daniel; Easteal, Ron; Bardana, Davide D

    2017-01-01

    The purpose of this study was to examine the safety of an arthroscopic technique for acromioclavicular joint (ACJ) reconstruction by investigating its proximity to important neurovascular structures. Six shoulders from 4 cadaveric specimens were used for ACJ reconstruction in this study. The procedure consists of performing an arthroscopic acromioclavicular (AC) reduction with a double button construct, followed by coracoclavicular ligament reconstruction without drilling clavicular tunnels. Shoulders were subsequently dissected in order to identify and measure distances to adjacent neurovascular structures. The suprascapular artery and nerve were the closest neurovascular structures to implanted materials. The mean distances were 8.2 (standard deviation [SD] = 3.6) mm to the suprascapular nerve and 5.6 (SD = 4.2) mm to the suprascapular artery. The mean distance of the suprascapular nerve from implants was found to be greater than 5 mm (P = .040), while the distance to the suprascapular artery was not (P > .5). Neither difference was statistically significant (P = .80 for artery; P = .08 for nerve). Mini-open, arthroscopically assisted ACJ reconstruction safely avoids the surrounding nerves, with no observed damage to any neurovascular structures including the suprascapular nerve and artery, and may be a viable alternative to open techniques. However, surgeons must remain cognizant of possible close proximity to the suprascapular artery. This study represents an evaluation of the safety and feasibility of a minimally invasive ACJ reconstruction as it relates to the proximity of neurovascular structures. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  7. Palmar reconstruction of the triangular fibrocartilage complex for instability of the distal radioulnar joint: a biomechanical study.

    PubMed

    Kataoka, T; Moritomo, H; Omokawa, S; Iida, A; Wada, T; Aoki, M

    2013-06-01

    We developed a new triangular fibrocartilage complex reconstruction technique for distal radioulnar joint instability in which the palmar portion of the triangular fibrocartilage complex was predominantly reconstructed, and evaluated whether such reconstruction can restore stability of the distal radioulnar joint in seven fresh cadaver upper extremities. Distal radioulnar joint instability was induced by cutting all soft-tissue stabilizers around the distal ulna. Using a palmar approach, a palmaris longus tendon graft was sutured to the remnant of the palmar radioulnar and ulnocarpal ligaments. The graft was then passed through a bone tunnel created at the fovea and was sutured. Loads were applied to the radius, and dorsopalmar displacements of the radius relative to the ulna were measured using an electromagnetic tracking device in neutral rotation, 60° supination and 60° pronation. We compared the dorsopalmar displacements before sectioning, before reconstruction and after reconstruction. Dorsopalmar instability produced by sectioning significantly improved in all forearm positions after reconstruction.

  8. Accuracy of acromioclavicular joint injections.

    PubMed

    Wasserman, Bradley R; Pettrone, Sarah; Jazrawi, Laith M; Zuckerman, Joseph D; Rokito, Andrew S

    2013-01-01

    Injection to the acromioclavicular (AC) joint can be both diagnostic and therapeutic. The purpose of this study was to evaluate the accuracy of in vivo AC joint injections. Case series; Level of evidence, 4. Thirty patients with pain localized to the AC joint were injected with 1 mL of 1% lidocaine and 0.5 mL of radiographic contrast material (Isovue). Radiographs of the AC joint were taken after the injection. Each radiograph was reviewed by a musculoskeletal radiologist and graded as intra-articular, extra-articular, or partially intra-articular. Of the 30 injections performed, 13 (43.3%) were intra-articular, 7 (23.3%) were partially articular, and 10 (33.3%) were extra-articular. When the intra-articular and the partially articular groups were combined, 20 patients (66.7%) had some contrast dye in the AC joint. This study demonstrates that despite the relatively superficial location of the AC joint, the clinical accuracy of AC joint injections remains relatively low.

  9. A New Joint-Blade SENSE Reconstruction for Accelerated PROPELLER MRI.

    PubMed

    Lyu, Mengye; Liu, Yilong; Xie, Victor B; Feng, Yanqiu; Guo, Hua; Wu, Ed X

    2017-02-16

    PROPELLER technique is widely used in MRI examinations for being motion insensitive, but it prolongs scan time and is restricted mainly to T2 contrast. Parallel imaging can accelerate PROPELLER and enable more flexible contrasts. Here, we propose a multi-step joint-blade (MJB) SENSE reconstruction to reduce the noise amplification in parallel imaging accelerated PROPELLER. MJB SENSE utilizes the fact that PROPELLER blades contain sharable information and blade-combined images can serve as regularization references. It consists of three steps. First, conventional blade-combined images are obtained using the conventional simple single-blade (SSB) SENSE, which reconstructs each blade separately. Second, the blade-combined images are employed as regularization for blade-wise noise reduction. Last, with virtual high-frequency data resampled from the previous step, all blades are jointly reconstructed to form the final images. Simulations were performed to evaluate the proposed MJB SENSE for noise reduction and motion correction. MJB SENSE was also applied to both T2-weighted and T1-weighted in vivo brain data. Compared to SSB SENSE, MJB SENSE greatly reduced the noise amplification at various acceleration factors, leading to increased image SNR in all simulation and in vivo experiments, including T1-weighted imaging with short echo trains. Furthermore, it preserved motion correction capability and was computationally efficient.

  10. Evaluation of an intact, an ACL-deficient, and a reconstructed human knee joint finite element model.

    PubMed

    Vairis, Achilles; Stefanoudakis, George; Petousis, Markos; Vidakis, Nectarios; Tsainis, Andreas-Marios; Kandyla, Betina

    2016-02-01

    The human knee joint has a three-dimensional geometry with multiple body articulations that produce complex mechanical responses under loads that occur in everyday life and sports activities. Understanding the complex mechanical interactions of these load-bearing structures is of use when the treatment of relevant diseases is evaluated and assisting devices are designed. The anterior cruciate ligament (ACL) in the knee is one of four main ligaments that connects the femur to the tibia and is often torn during sudden twisting motions, resulting in knee instability. The objective of this work is to study the mechanical behavior of the human knee joint and evaluate the differences in its response for three different states, i.e., intact, ACL-deficient, and surgically treated (reconstructed) knee. The finite element models corresponding to these states were developed. For the reconstructed model, a novel repair device was developed and patented by the author in previous work. Static load cases were applied, as have already been presented in a previous work, in order to compare the calculated results produced by the two models the ACL-deficient and the surgically reconstructed knee joint, under the exact same loading conditions. Displacements were calculated in different directions for the load cases studied and were found to be very close to those from previous modeling work and were in good agreement with experimental data presented in literature. The developed finite element model for both the intact and the ACL-deficient human knee joint is a reliable tool to study the kinematics of the human knee, as results of this study show. In addition, the reconstructed human knee joint model had kinematic behavior similar to the intact knee joint, showing that such reconstruction devices can restore human knee stability to an adequate extent.

  11. Direct Parametric Reconstruction With Joint Motion Estimation/Correction for Dynamic Brain PET Data.

    PubMed

    Jiao, Jieqing; Bousse, Alexandre; Thielemans, Kris; Burgos, Ninon; Weston, Philip S J; Schott, Jonathan M; Atkinson, David; Arridge, Simon R; Hutton, Brian F; Markiewicz, Pawel; Ourselin, Sebastien

    2017-01-01

    Direct reconstruction of parametric images from raw photon counts has been shown to improve the quantitative analysis of dynamic positron emission tomography (PET) data. However it suffers from subject motion which is inevitable during the typical acquisition time of 1-2 hours. In this work we propose a framework to jointly estimate subject head motion and reconstruct the motion-corrected parametric images directly from raw PET data, so that the effects of distorted tissue-to-voxel mapping due to subject motion can be reduced in reconstructing the parametric images with motion-compensated attenuation correction and spatially aligned temporal PET data. The proposed approach is formulated within the maximum likelihood framework, and efficient solutions are derived for estimating subject motion and kinetic parameters from raw PET photon count data. Results from evaluations on simulated [ 11 C]raclopride data using the Zubal brain phantom and real clinical [ 18 F]florbetapir data of a patient with Alzheimer's disease show that the proposed joint direct parametric reconstruction motion correction approach can improve the accuracy of quantifying dynamic PET data with large subject motion.

  12. Effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction.

    PubMed

    Shim, Jae-Kwang; Choi, Ho-Suk; Shin, Jun-Ho

    2015-12-01

    [Purpose] This study examined the effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 16 adults who underwent arthroscopic anterior cruciate reconstruction and neuromuscular training. The Lysholm scale was used to assess functional disorders on the affected knee joint. A KT-2000 arthrometer was used to measure anterior displacement of the tibia against the femur. Surface electromyography was used to detect the muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus before and after neuromuscular training. [Results] There was significant relaxation in tibial anterior displacement of the affected and sound sides in the supine position before neuromuscular training. Furthermore, the difference in the tibial anterior displacement of the affected knee joints in the standing position was reduced after neuromuscular training. Moreover, the variation of the muscle activation evoked higher muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus. [Conclusion] Neuromuscular training may improve functional joint stability in patients with orthopedic musculoskeletal injuries in the postoperative period.

  13. Effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction

    PubMed Central

    Shim, Jae-Kwang; Choi, Ho-Suk; Shin, Jun-Ho

    2015-01-01

    [Purpose] This study examined the effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 16 adults who underwent arthroscopic anterior cruciate reconstruction and neuromuscular training. The Lysholm scale was used to assess functional disorders on the affected knee joint. A KT-2000 arthrometer was used to measure anterior displacement of the tibia against the femur. Surface electromyography was used to detect the muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus before and after neuromuscular training. [Results] There was significant relaxation in tibial anterior displacement of the affected and sound sides in the supine position before neuromuscular training. Furthermore, the difference in the tibial anterior displacement of the affected knee joints in the standing position was reduced after neuromuscular training. Moreover, the variation of the muscle activation evoked higher muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus. [Conclusion] Neuromuscular training may improve functional joint stability in patients with orthopedic musculoskeletal injuries in the postoperative period. PMID:26834316

  14. A New Joint-Blade SENSE Reconstruction for Accelerated PROPELLER MRI

    PubMed Central

    Lyu, Mengye; Liu, Yilong; Xie, Victor B.; Feng, Yanqiu; Guo, Hua; Wu, Ed X.

    2017-01-01

    PROPELLER technique is widely used in MRI examinations for being motion insensitive, but it prolongs scan time and is restricted mainly to T2 contrast. Parallel imaging can accelerate PROPELLER and enable more flexible contrasts. Here, we propose a multi-step joint-blade (MJB) SENSE reconstruction to reduce the noise amplification in parallel imaging accelerated PROPELLER. MJB SENSE utilizes the fact that PROPELLER blades contain sharable information and blade-combined images can serve as regularization references. It consists of three steps. First, conventional blade-combined images are obtained using the conventional simple single-blade (SSB) SENSE, which reconstructs each blade separately. Second, the blade-combined images are employed as regularization for blade-wise noise reduction. Last, with virtual high-frequency data resampled from the previous step, all blades are jointly reconstructed to form the final images. Simulations were performed to evaluate the proposed MJB SENSE for noise reduction and motion correction. MJB SENSE was also applied to both T2-weighted and T1-weighted in vivo brain data. Compared to SSB SENSE, MJB SENSE greatly reduced the noise amplification at various acceleration factors, leading to increased image SNR in all simulation and in vivo experiments, including T1-weighted imaging with short echo trains. Furthermore, it preserved motion correction capability and was computationally efficient. PMID:28205602

  15. Reconstruction of shifting elbow joint compliant characteristics during fast and slow movements.

    PubMed

    Latash, M L; Gottlieb, G L

    1991-01-01

    The purpose of this study was to experimentally investigate the applicability of the equilibrium-point hypothesis to the dynamics of single-joint movements. Subjects were trained to perform relatively slow (movement time 600-1000 ms) or fast (movement time 200-300 ms) single-joint elbow flexion movements against a constant extending torque bias. They were instructed to reproduce the same time pattern of central motor command for a series of movements when the external torque could slowly and unpredictably increase, decrease, or remain constant. For fast movements, the total muscle torque was calculated as a sum of external and inertial components. Analysis of the data allowed reconstruction of the elbow joint compliant characteristics at different times during execution of the learned motor command. "Virtual" trajectories of the movements, representing time-varying changes in a central control parameter, were reconstructed and compared with the "actual" trajectories. For slow movements, the actual trajectories lagged behind the virtual ones. There were no consistent changes in the joint stiffness during slow movements. Similar analysis of experiments without voluntary movements demonstrated a lack of changes in the central parameters, supporting the assumption that the subjects were able to keep the same central motor command in spite of externally imposed unexpected torque perturbations. For the fast movements, the virtual trajectories were N-shaped, and the joint stiffness demonstrated a considerable increase near the middle of the movement. These findings contradict an hypothesis of monotonic joint compliant characteristic translation at a nearly constant rate during such movements.

  16. Modified Weaver-Dunn Procedure Versus The Use of Semitendinosus Autogenous Tendon Graft for Acromioclavicular Joint Reconstruction.

    PubMed

    Hegazy, Galal; Safwat, Hesham; Seddik, Mahmoud; Al-Shal, Ehab A; Al-Sebai, Ibrahim; Negm, Mohame

    2016-01-01

    The optimal operative method for acromioclavicular joint reconstruction remains controversial. The modified Weaver-Dunn method is one of the most popular methods. Anatomic reconstruction of coracoclavicular ligaments with autogenous tendon grafts, widely used in treating chronic acromioclavicular joint instability, reportedly diminishes pain, eliminates sequelae, and improves function as well as strength. To compare clinical and radiologic outcomes between a modified Weaver-Dunn procedure and an anatomic coracoclavicular ligaments reconstruction technique using autogenous semitendinosus tendon graft. Twenty patients (mean age, 39 years) with painful, chronic Rockwood type III acromioclavicular joint dislocations were subjected to surgical reconstruction. In ten patients, a modified Weaver-Dunn procedure was performed, in the other ten patients; autogenous semitendinosus tendon graft was used. The mean time between injury and the index procedure was 18 month (range from 9 - 28). Clinical evaluation was performed using the Oxford Shoulder Score and Nottingham Clavicle Score after a mean follow-up time of 27.8 months. Preoperative and postoperative radiographs were compared. In the Weaver-Dunn group the Oxford Shoulder Score improved from 25±4 to 40±2 points. While the Nottingham Clavicle Score increased from 48±7 to 84±11. In semitendinosus tendon graft group, the Oxford Shoulder Score improved from 25±3 points to 50±2 points and the Nottingham Clavicle Score from 48±8 points to 95±8, respectively. Acromioclavicular joint reconstruction using the semitendinosus tendon graft achieved better Oxford Shoulder Score and Nottingham Clavicle Score compared to the modified Weaver-Dunn procedure.

  17. Modified Weaver-Dunn Procedure Versus The Use of Semitendinosus Autogenous Tendon Graft for Acromioclavicular Joint Reconstruction

    PubMed Central

    Hegazy, Galal; Safwat, Hesham; Seddik, Mahmoud; Al-shal, Ehab A.; Al-Sebai, Ibrahim; Negm, Mohame

    2016-01-01

    Background: The optimal operative method for acromioclavicular joint reconstruction remains controversial. The modified Weaver-Dunn method is one of the most popular methods. Anatomic reconstruction of coracoclavicular ligaments with autogenous tendon grafts, widely used in treating chronic acromioclavicular joint instability, reportedly diminishes pain, eliminates sequelae, and improves function as well as strength. Objective: To compare clinical and radiologic outcomes between a modified Weaver-Dunn procedure and an anatomic coracoclavicular ligaments reconstruction technique using autogenous semitendinosus tendon graft. Methods: Twenty patients (mean age, 39 years) with painful, chronic Rockwood type III acromioclavicular joint dislocations were subjected to surgical reconstruction. In ten patients, a modified Weaver-Dunn procedure was performed, in the other ten patients; autogenous semitendinosus tendon graft was used. The mean time between injury and the index procedure was 18 month (range from 9 – 28). Clinical evaluation was performed using the Oxford Shoulder Score and Nottingham Clavicle Score after a mean follow-up time of 27.8 months. Preoperative and postoperative radiographs were compared. Results: In the Weaver-Dunn group the Oxford Shoulder Score improved from 25±4 to 40±2 points. While the Nottingham Clavicle Score increased from 48±7 to 84±11. In semitendinosus tendon graft group, the Oxford Shoulder Score improved from 25±3 points to 50±2 points and the Nottingham Clavicle Score from 48±8 points to 95±8, respectively. Conclusion: Acromioclavicular joint reconstruction using the semitendinosus tendon graft achieved better Oxford Shoulder Score and Nottingham Clavicle Score compared to the modified Weaver-Dunn procedure. PMID:27347245

  18. Post-operative bracing after ACL reconstruction has no effect on knee joint effusion. A prospective, randomized study.

    PubMed

    Lindström, Maria; Wredmark, Torsten; Wretling, Marie-Louise; Henriksson, Marketta; Felländer-Tsai, Li

    2015-12-01

    It is unclear what factors contribute to knee joint effusion after anterior cruciate ligament (ACL) injury and reconstruction. Knee homeostasis after injury and surgery is crucial for rehabilitation and knee well-being. We examined if effusion was affected by post-operative bracing, and if patients with effusion fit into a common profile. Patients were randomized to wearing or not wearing a post-operative brace for three weeks after ACL reconstruction with semitendinosus-gracilis tendons. Knee joint effusion was detected by computed tomography in 60 patients (22 women), before and three and 12 months after surgery. Joint effusion, clinical and subjective tests were analyzed. This is the first prospective, randomized study on post-operative bracing for patients with a semitendinosus-gracilis graft showed that bracing had no effect on three-months presence of joint effusion. Excessive joint effusion was present in 68% of the patients three months after surgery and was associated to prior meniscus injury (p=0.05) and higher prior Tegner activity level (p=0.006). We found a positive association between longer time from injury to surgery and joint effusion three months post-operatively (rho=0.29, p<0.05). Twelve months post-operatively, joint effusion had diminished to baseline levels. Subjective scores and activity levels were lower for women. Three-months joint effusion predicted lower final outcome scores in women. Prior meniscus injury and pre-injury Tegner activity levels are predictive significant variables for excessive knee joint effusion after ACL reconstruction. Post-operative bracing had no effect. A larger clinical cohort is needed to confirm findings of this logistic regression. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Gender differences in the restoration of knee joint biomechanics during gait after anterior cruciate ligament reconstruction.

    PubMed

    Asaeda, Makoto; Deie, Masataka; Fujita, Naoto; Kono, Yoshifumi; Terai, Chiaki; Kuwahara, Wataru; Watanabe, Hodaka; Kimura, Hiroaki; Adachi, Nobuo; Sunagawa, Toru; Ochi, Mitsuo

    2017-03-01

    The aim of our study was to evaluate the effects of gender on recovery of knee joint biomechanics over the stance phase of gait after reconstruction of the anterior cruciate ligament (ACL). Gait parameters and knee joint kinematics and kinetics were compared in 32 patients (16 male and 16 female) who underwent ACL reconstruction for a unilateral ACL deficiency, with comparison to an age-, height-, and weight-matched Control group. Knee flexion, adduction and tibial rotation angles were measured and knee extension and abduction moment was calculated by inverse dynamics methods. Females exhibited more tibial external rotation, in both the Control and ACL groups (P<0.05), which was not changed after ACL reconstruction. Prior to reconstruction, sagittal plane biomechanics were changed, in both males and females, compared to the Control groups (P<0.05). These abnormal sagittal plane mechanics were recovered at 12months, but not six months post-reconstruction. We identified gender-based differences in tibial rotation that influenced the kinematics and kinetics of the knee over the stance phase of gait, both pre-operatively and post-ACL reconstruction. Evaluation of biomechanical effects of ACL injury, before and after reconstruction, should be separately evaluated for females and males. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Can the ACS-NSQIP surgical risk calculator predict post-operative complications in patients undergoing flap reconstruction following soft tissue sarcoma resection?

    PubMed

    Slump, Jelena; Ferguson, Peter C; Wunder, Jay S; Griffin, Anthony; Hoekstra, Harald J; Bagher, Shaghayegh; Zhong, Toni; Hofer, Stefan O P; O'Neill, Anne C

    2016-10-01

    The ACS-NSQIP surgical risk calculator is an open-access on-line tool that estimates the risk of adverse post-operative outcomes for a wide range of surgical procedures. Wide surgical resection of soft tissue sarcoma (STS) often requires complex reconstructive procedures that can be associated with relatively high rates of complications. This study evaluates the ability of this calculator to identify patients with STS at risk for post-operative complications following flap reconstruction. Clinical details of 265 patients who underwent flap reconstruction following STS resection were entered into the online calculator. The predicted rates of complications were compared to the observed rates. The calculator model was validated using measures of prediction and discrimination. The mean predicted rate of any complication was 15.35 ± 5.6% which differed significantly from the observed rate of 32.5% (P = 0.009). The c-statistic was relatively low at 0.626 indicating poor discrimination between patients who are at risk of complications and those who are not. The Brier's score of 0.242 was significantly different from 0 (P < 0.001) indicating poor correlation between the predicted and actual probability of complications. The ACS-NSQIP universal risk calculator did not maintain its predictive value in patients undergoing flap reconstruction following STS resection. J. Surg. Oncol. 2016;114:570-575. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Scleroderma and the temporomandibular joint: reconstruction in 2 variants.

    PubMed

    MacIntosh, Robert Bruce; Shivapuja, Prasanna-Kumar; Naqvi, Rabia

    2015-06-01

    This article reviews the pathophysiology of scleroderma (systemic sclerosis [SSc]) and its destructive effects on the mandible in general and the temporomandibular joint (TMJ) in particular. It discusses the considerations of operating on patients with devastating chronic disease and presents 2 cases of TMJ reconstruction in patients with the diagnosis. Two patients with different degrees of SSc involvement underwent TMJ reconstruction with costochondral grafts. The patients represent the surgical considerations pertinent to this disease and different outcomes as determined by the variance in severity of their afflictions. The 2 patients tolerated the surgeries well and exhibited improvement in function in the long-term. One patient thrives and continues to do well despite her SSc approximately 10 years postoperatively; the second patient died of her disease approximately 9 years after her initial surgical care. The experience with these 2 cases showed that patients with SSc can safely undergo TMJ reconstruction with anticipated good results, but that the overall severity of the disease remains paramount in determining the feasibility of corrective surgery under this diagnosis. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  2. The pedicle screw-rod system is an acceptable method of reconstructive surgery after resection of sacroiliac joint tumours

    PubMed Central

    Zhou, Yi-Jun; Yunus, Akbar; Tian, Zheng; Chen, Jiang-Tao; Wang, Chong; Xu, Lei-Lei

    2016-01-01

    Hemipelvic resections for primary bone tumours require reconstruction to restore weight bearing along anatomic axes. However, reconstruction of the pelvic arch remains a major surgical challenge because of the high rate of associated complications. We used the pedicle screw-rod system to reconstruct the pelvis, and the purpose of this investigation was to assess the oncology, functional outcome and complication rate following this procedure. The purpose of this study was to investigate the operative indications and technique of the pedicle screw-rod system in reconstruction of the stability of the sacroiliac joint after resection of sacroiliac joint tumours. The average MSTS (Musculoskeletal Tumour Society) score was 26.5 at either three months after surgery or at the latest follow-up. Seven patients had surgery-related complications, including wound dehiscence in one, infection in two, local necrosis in four (including infection in two), sciatic nerve palsy in one and pubic symphysis subluxation in one. There was no screw loosening or deep vein thrombosis occurring in this series. Using a pedicle screw-rod after resection of a sacroiliac joint tumour is an acceptable method of pelvic reconstruction because of its reduced risk of complications and satisfactory functional outcome, as well as its feasibility of reconstruction for type IV pelvis tumour resection without elaborate preoperative customisation. Level of evidence: Level IV, therapeutic study. PMID:27095944

  3. Joint image reconstruction method with correlative multi-channel prior for x-ray spectral computed tomography

    NASA Astrophysics Data System (ADS)

    Kazantsev, Daniil; Jørgensen, Jakob S.; Andersen, Martin S.; Lionheart, William R. B.; Lee, Peter D.; Withers, Philip J.

    2018-06-01

    Rapid developments in photon-counting and energy-discriminating detectors have the potential to provide an additional spectral dimension to conventional x-ray grayscale imaging. Reconstructed spectroscopic tomographic data can be used to distinguish individual materials by characteristic absorption peaks. The acquired energy-binned data, however, suffer from low signal-to-noise ratio, acquisition artifacts, and frequently angular undersampled conditions. New regularized iterative reconstruction methods have the potential to produce higher quality images and since energy channels are mutually correlated it can be advantageous to exploit this additional knowledge. In this paper, we propose a novel method which jointly reconstructs all energy channels while imposing a strong structural correlation. The core of the proposed algorithm is to employ a variational framework of parallel level sets to encourage joint smoothing directions. In particular, the method selects reference channels from which to propagate structure in an adaptive and stochastic way while preferring channels with a high data signal-to-noise ratio. The method is compared with current state-of-the-art multi-channel reconstruction techniques including channel-wise total variation and correlative total nuclear variation regularization. Realistic simulation experiments demonstrate the performance improvements achievable by using correlative regularization methods.

  4. Biomechanical Evaluation of Knee Joint Laxities and Graft Forces After Anterior Cruciate Ligament Reconstruction by Anteromedial Portal, Outside-In, and Transtibial Techniques

    PubMed Central

    Sim, Jae Ang; Gadikota, Hemanth R.; Li, Jing-Sheng; Li, Guoan; Gill, Thomas J.

    2013-01-01

    Background Recently, anatomic anterior cruciate ligament (ACL) reconstruction is emphasized to improve joint laxity and to potentially avert initiation of cartilage degeneration. There is a paucity of information on the efficacy of ACL reconstructions by currently practiced tunnel creation techniques in restoring normal joint laxity. Study Design Controlled laboratory study. Hypothesis Anterior cruciate ligament reconstruction by the anteromedial (AM) portal technique, outside-in (OI) technique, and modified transtibial (TT) technique can equally restore the normal knee joint laxity and ACL forces. Methods Eight fresh-frozen human cadaveric knee specimens were tested using a robotic testing system under an anterior tibial load (134 N) at 0°, 30°, 60°, and 90° of flexion and combined torques (10-N·m valgus and 5-N·m internal tibial torques) at 0° and 30° of flexion. Knee joint kinematics, ACL, and ACL graft forces were measured in each knee specimen under 5 different conditions (ACL-intact knee, ACL-deficient knee, ACL-reconstructed knee by AM portal technique, ACL-reconstructed knee by OI technique, and ACL-reconstructed knee by TT technique). Results Under anterior tibial load, no significant difference was observed between the 3 reconstructions in terms of restoring anterior tibial translation (P > .05). However, none of the 3 ACL reconstruction techniques could completely restore the normal anterior tibial translations (P <.05). Under combined tibial torques, both AM portal and OI techniques closely restored the normal knee anterior tibial translation (P > .05) at 0° of flexion but could not do so at 30° of flexion (P <.05). The ACL reconstruction by the TT technique was unable to restore normal anterior tibial translations at both 0° and 30° of flexion under combined tibial torques (P <.05). Forces experienced by the ACL grafts in the 3 reconstruction techniques were lower than those experienced by normal ACL under both the loading conditions

  5. Prediction of Knee Joint Contact Forces From External Measures Using Principal Component Prediction and Reconstruction.

    PubMed

    Saliba, Christopher M; Clouthier, Allison L; Brandon, Scott C E; Rainbow, Michael J; Deluzio, Kevin J

    2018-05-29

    Abnormal loading of the knee joint contributes to the pathogenesis of knee osteoarthritis. Gait retraining is a non-invasive intervention that aims to reduce knee loads by providing audible, visual, or haptic feedback of gait parameters. The computational expense of joint contact force prediction has limited real-time feedback to surrogate measures of the contact force, such as the knee adduction moment. We developed a method to predict knee joint contact forces using motion analysis and a statistical regression model that can be implemented in near real-time. Gait waveform variables were deconstructed using principal component analysis and a linear regression was used to predict the principal component scores of the contact force waveforms. Knee joint contact force waveforms were reconstructed using the predicted scores. We tested our method using a heterogenous population of asymptomatic controls and subjects with knee osteoarthritis. The reconstructed contact force waveforms had mean (SD) RMS differences of 0.17 (0.05) bodyweight compared to the contact forces predicted by a musculoskeletal model. Our method successfully predicted subject-specific shape features of contact force waveforms and is a potentially powerful tool in biofeedback and clinical gait analysis.

  6. Titanium clip ball joint: a partial ossicular reconstruction prosthesis.

    PubMed

    Beutner, Dirk; Luers, Jan Christoffer; Bornitz, Matthias; Zahnert, Thomas; Huttenbrink, Karl-Bernd

    2011-06-01

    To describe a new titanium clip prosthesis for partial ossicular reconstruction with a micro ball joint in the headplate for compensation of tympanic membrane displacements. Laboratory experiments followed by 18 consecutive patients. A micro ball joint was implemented into a headplate of titanium middle ear prosthesis. First, the new prosthesis was tested in the laboratory in temporal bone experiments. Second, the new prosthesis was clinically installed in 18 patients. Results of laser Doppler vibrometry and force measurements in the laboratory experiments, analysis of a questionnaire, and preoperative and postoperative pure tone audiometry. The frictional resistance in the joint was measured to be 12 mN that should allow for adequate mobility under physiologic conditions. The effective sound transmission of the prosthesis was demonstrated by laser Doppler vibrometry. Intraoperatively, the installation of the prosthesis was always straightforward with headplate prosthesis shaft angles between 60 and 90 degrees. Postoperatively, pure tone audiometry revealed satisfying hearing results with a remaining average air-bone gap of 18.2 dB over the frequencies 500, 1,000, 2,000, and 3,000 Hz. No signs of prosthesis dislocation were discovered within the follow-up period of approximately 6 months. The experimental data show that the new modified prosthesis headplate fulfills the requirements necessary for sound transmission. The joint allows the plate to follow movements of the tympanic membrane. This characteristic in conjunction with the proven clip design ensure for optimal prosthesis placement and effectiveness.

  7. Reduced step length reduces knee joint contact forces during running following anterior cruciate ligament reconstruction but does not alter inter-limb asymmetry.

    PubMed

    Bowersock, Collin D; Willy, Richard W; DeVita, Paul; Willson, John D

    2017-03-01

    Anterior cruciate ligament reconstruction is associated with early onset knee osteoarthritis. Running is a typical activity following this surgery, but elevated knee joint contact forces are thought to contribute to osteoarthritis degenerative processes. It is therefore clinically relevant to identify interventions to reduce contact forces during running among individuals after anterior cruciate ligament reconstruction. The primary purpose of this study was to evaluate the effect of reducing step length during running on patellofemoral and tibiofemoral joint contact forces among people with a history of anterior cruciate ligament reconstruction. Inter limb knee joint contact force differences during running were also examined. 18 individuals at an average of 54.8months after unilateral anterior cruciate ligament reconstruction ran in 3 step length conditions (preferred, -5%, -10%). Bilateral patellofemoral, tibiofemoral, and medial tibiofemoral compartment peak force, loading rate, impulse, and impulse per kilometer were evaluated between step length conditions and limbs using separate 2 factor analyses of variance. Reducing step length 5% decreased patellofemoral, tibiofemoral, and medial tibiofemoral compartment peak force, impulse, and impulse per kilometer bilaterally. A 10% step length reduction further decreased peak forces and force impulses, but did not further reduce force impulses per kilometer. Tibiofemoral joint impulse, impulse per kilometer, and patellofemoral joint loading rate were lower in the previously injured limb compared to the contralateral limb. Running with a shorter step length is a feasible clinical intervention to reduce knee joint contact forces during running among people with a history of anterior cruciate ligament reconstruction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Altered lower extremity joint mechanics occur during the star excursion balance test and single leg hop after ACL-reconstruction in a collegiate athlete.

    PubMed

    Samaan, Michael A; Ringleb, Stacie I; Bawab, Sebastian Y; Greska, Eric K; Weinhandl, Joshua T

    2018-03-01

    The effects of ACL-reconstruction on lower extremity joint mechanics during performance of the Star Excursion Balance Test (SEBT) and Single Leg Hop (SLH) are limited. The purpose of this study was to determine if altered lower extremity mechanics occur during the SEBT and SLH after ACL-reconstruction. One female Division I collegiate athlete performed the SEBT and SLH tasks, bilaterally, both before ACL injury and 27 months after ACL-reconstruction. Maximal reach, hop distances, lower extremity joint kinematics and moments were compared between both time points. Musculoskeletal simulations were used to assess muscle force production during the SEBT and SLH at both time points. Compared to the pre-injury time point, SEBT reach distances were similar in both limbs after ACL-reconstruction except for the max anterior reach distance in the ipsilateral limb. The athlete demonstrated similar hop distances, bilaterally, after ACL-reconstruction compared to the pre-injury time point. Despite normal functional performance during the SEBT and SLH, the athlete exhibited altered lower extremity joint mechanics during both of these tasks. These results suggest that measuring the maximal reach and hop distances for these tasks, in combination with an analysis of the lower extremity joint mechanics that occur after ACL-reconstruction, may help clinicians and researchers to better understand the effects of ACL-reconstruction on the neuromuscular system during the SEBT and SLH.

  9. Simultaneous distribution of AC and DC power

    DOEpatents

    Polese, Luigi Gentile

    2015-09-15

    A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

  10. Does the graft-tunnel friction influence knee joint kinematics and biomechanics after anterior cruciate ligament reconstruction? A finite element study.

    PubMed

    Wan, Chao; Hao, Zhixiu

    2018-02-01

    Graft tissues within bone tunnels remain mobile for a long time after anterior cruciate ligament (ACL) reconstruction. However, whether the graft-tunnel friction affects the finite element (FE) simulation of the ACL reconstruction is still unclear. Four friction coefficients (from 0 to 0.3) were simulated in the ACL-reconstructed joint model as well as two loading levels of anterior tibial drawer. The graft-tunnel friction did not affect joint kinematics and the maximal principal strain of the graft. By contrast, both the relative graft-tunnel motion and equivalent strain for the bone tunnels were altered, which corresponded to different processes of graft-tunnel integration and bone remodeling, respectively. It implies that the graft-tunnel friction should be defined properly for studying the graft-tunnel integration or bone remodeling after ACL reconstruction using numerical simulation.

  11. Protocol for concomitant temporomandibular joint custom-fitted total joint reconstruction and orthognathic surgery utilizing computer-assisted surgical simulation.

    PubMed

    Movahed, Reza; Teschke, Marcus; Wolford, Larry M

    2013-12-01

    Clinicians who address temporomandibular joint (TMJ) pathology and dentofacial deformities surgically can perform the surgery in 1 stage or 2 separate stages. The 2-stage approach requires the patient to undergo 2 separate operations and anesthesia, significantly prolonging the overall treatment. However, performing concomitant TMJ and orthognathic surgery (CTOS) in these cases requires careful treatment planning and surgical proficiency in the 2 surgical areas. This article presents a new treatment protocol for the application of computer-assisted surgical simulation in CTOS cases requiring reconstruction with patient-fitted total joint prostheses. The traditional and new CTOS protocols are described and compared. The new CTOS protocol helps decrease the preoperative workup time and increase the accuracy of model surgery. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  12. Acromioclavicular joint reconstruction using the LockDown synthetic implant: a study with cadavers.

    PubMed

    Taranu, R; Rushton, P R P; Serrano-Pedraza, I; Holder, L; Wallace, W A; Candal-Couto, J J

    2015-12-01

    Dislocation of the acromioclavicular joint is a relatively common injury and a number of surgical interventions have been described for its treatment. Recently, a synthetic ligament device has become available and been successfully used, however, like other non-native solutions, a compromise must be reached when choosing non-anatomical locations for their placement. This cadaveric study aimed to assess the effect of different clavicular anchorage points for the Lockdown device on the reduction of acromioclavicular joint dislocations, and suggest an optimal location. We also assessed whether further stability is provided using a coracoacromial ligament transfer (a modified Neviaser technique). The acromioclavicular joint was exposed on seven fresh-frozen cadaveric shoulders. The joint was reconstructed using the Lockdown implant using four different clavicular anchorage points and reduction was measured. The coracoacromial ligament was then transferred to the lateral end of the clavicle, and the joint re-assessed. If the Lockdown ligament was secured at the level of the conoid tubercle, the acromioclavicular joint could be reduced anatomically in all cases. If placed medial or 2 cm lateral, the joint was irreducible. If the Lockdown was placed 1 cm lateral to the conoid tubercle, the joint could be reduced with difficulty in four cases. Correct placement of the Lockdown device is crucial to allow anatomical joint reduction. Even when the Lockdown was placed over the conoid tubercle, anterior clavicle displacement remained but this could be controlled using a coracoacromial ligament transfer. ©2015 The British Editorial Society of Bone & Joint Surgery.

  13. Wide field of view CT and acromioclavicular joint instability: A technical innovation.

    PubMed

    Dyer, David R; Troupis, John M; Kamali Moaveni, Afshin

    2015-06-01

    A 21-year-old female with a traumatic shoulder injury is investigated and managed for symptoms relating to this injury. Pathology at the acromioclavicular joint is detected clinically; however, clinical examination and multiple imaging modalities do not reach a unified diagnosis on the grading of this acromioclavicular joint injury. When management appropriate to that suggested injury grading fail to help the patient's symptoms, further investigation methods were utilised. Wide field of view, dynamic CT (4D CT) is conducted on the patient's affected shoulder using a 320 × 0.5 mm detector multislice CT. Scans were conducted with a static table as the patient completed three movements of the affected shoulder. Capturing multiple data sets per second over a z-axis of 16 cm, measurements of the acromioclavicular joint were made, to show dynamic changes at the joint. Acromioclavicular (AC) joint translations were witnessed in three planes (a previously unrecognised pathology in the grading of acromioclavicular joint injuries). Translation in multiple planes was also not evident on careful clinical examination of this patient. AC joint width, anterior-posterior translation, superior-inferior translation and coracoclavicular width were measured with planar reconstructions while volume-rendered images and dynamic sequences aiding visual understanding of the pathology. Wide field of view dynamic CT (4D CT) is an accurate and quick modality to diagnose complex acromioclavicular joint injury. It provides dynamic information that no other modality can; 4D CT shows future benefits for clinical approach to diagnosis and management of acromioclavicular joint injury, and other musculoskeletal pathologies. © 2015 The Royal Australian and New Zealand College of Radiologists.

  14. Biomechanical characteristics of hemi-hamate reconstruction versus volar plate arthroplasty in the treatment of dorsal fracture dislocations of the proximal interphalangeal joint.

    PubMed

    Tyser, Andrew R; Tsai, Michael A; Parks, Brent G; Means, Kenneth R

    2015-02-01

    To compare stability and range of motion after hemi-hamate reconstruction versus volar plate arthroplasty in a biomechanical proximal interphalangeal (PIP) joint fracture-dislocation model. Eighteen digits from 6 cadaver hands were tested. We created defects of 40%, 60%, and 80% in the palmar base of each digit's middle phalanx, simulating an acute PIP joint fracture-dislocation. Each defect scenario was reconstructed with a hemi-hamate arthroplasty followed by a volar plate arthroplasty. A computer-controlled mechanism was used to bring each digit's PIP joint from full extension to full flexion via the digital tendons in each testing state, and in the intact state. During each testing scenario we collected PIP joint cinedata in a true lateral projection using mini-fluoroscopy. A digital radiography program was used to measure the amount of middle phalanx dorsal translation (subluxation) in full PIP joint extension. We recorded the angle at which subluxation, if present, occurred during each testing scenario. Average dorsal displacement of the middle phalanx in relation to the proximal phalanx was 0.01 mm for the hemi-hamate reconstructed joints and -0.03 mm for the volar plate arthroplasty, compared with the intact state. Flexion contractures were noted in each of the specimens reconstructed with volar plate arthroplasty. Degree of contracture was directly correlated with defect size, averaging 20° for 40% defects, 35° for 60% defects, and 60° for 80% defects. We observed no flexion contractures in the hemi-hamate reconstructions. Surgeons can use both hemi-hamate and volar plate arthroplasty to restore PIP joint stability following a fracture dislocation with a large middle phalanx palmar base defect. Use of volar plate arthroplasty led to an increasing flexion contracture as the middle phalanx palmar base defect increased. Clinicians can use the information from this study to help with surgical decision-making and patient education. Copyright © 2015

  15. Surgical Reconstruction with the Remnant Ligament Improves Joint Position Sense as well as Functional Ankle Instability: A 1-Year Follow-Up Study

    PubMed Central

    Iwao, Kamizato; Masataka, Deie; Kohei, Fukuhara

    2014-01-01

    Introduction. Chronic functional instability—characterized by repeated ankle inversion sprains and a subjective sensation of instability—is one of the most common residual disabilities after an inversion sprain. However, whether surgical reconstruction improves sensorimotor control has not been reported to date. The purpose of this study was to assess functional improvement of chronic ankle instability after surgical reconstruction using the remnant ligament. Materials and Methods. We performed 10 cases in the intervention group and 20 healthy individuals as the control group. Before and after surgical reconstruction, we evaluated joint position sense and functional ankle instability by means of a questionnaire. Results and Discussion. There was a statistically significant difference between the control and intervention groups before surgical reconstruction. Three months after surgery in the intervention group, the joint position sense was significantly different from those found preoperatively. Before surgery, the mean score of functional ankle instability in the intervention group was almost twice as low. Three months after surgery, however, the score significantly increased. The results showed that surgical reconstruction using the remnant ligament was effective not only for improving mechanical retensioning but also for ameliorating joint position sense and functional ankle instability. PMID:25401146

  16. Effect of Direct Ligament Repair and Tenodesis Reconstruction on Simulated Subtalar Joint Instability.

    PubMed

    Choisne, Julie; Hoch, Matthew C; Alexander, Ian; Ringleb, Stacie I

    2017-03-01

    Subtalar instability is associated with up to 80% of patients presenting with chronic ankle instability but is often not considered in the diagnosis or treatment. Operative procedures to repair ankle instability have shown good clinical results, but the effects of these reconstruction procedures on isolated subtalar instability are not well understood. The goal of this study was to investigate the effect of the Gould modification of the Broström procedure and a new tenodesis reconstruction procedure on ankle and subtalar joint kinematics after simulating a subtalar injury. Kinematic data were collected on 7 cadaveric ankles during inversion through the range of ankle flexion and during internal rotation. Testing was performed on the intact foot; after sectioning the calcaneofibular ligament, cervical ligament, and interosseous talocalcaneal ligament; after the Gould modification of the Broström procedure was performed; and after tenodesis was performed and sutures from the Gould modification removed. The Gould modification of the Broström procedure significantly decreased subtalar and ankle inversion motion and subtalar internal rotation compared to the unstable condition. The tenodesis method restricted internal rotation at the subtalar joint and ankle inversion compared to the intact state. Both operative procedures improved stability of the ankle complex, but tenodesis was unable to restore subtalar inversion and restricted ankle inversion in maximum plantarflexion. The Gould modification of Broström ligament repair may be a favorable operative procedure for the restoration of subtalar and ankle joint kinematics.

  17. Reconstructing Interlaced High-Dynamic-Range Video Using Joint Learning.

    PubMed

    Inchang Choi; Seung-Hwan Baek; Kim, Min H

    2017-11-01

    For extending the dynamic range of video, it is a common practice to capture multiple frames sequentially with different exposures and combine them to extend the dynamic range of each video frame. However, this approach results in typical ghosting artifacts due to fast and complex motion in nature. As an alternative, video imaging with interlaced exposures has been introduced to extend the dynamic range. However, the interlaced approach has been hindered by jaggy artifacts and sensor noise, leading to concerns over image quality. In this paper, we propose a data-driven approach for jointly solving two specific problems of deinterlacing and denoising that arise in interlaced video imaging with different exposures. First, we solve the deinterlacing problem using joint dictionary learning via sparse coding. Since partial information of detail in differently exposed rows is often available via interlacing, we make use of the information to reconstruct details of the extended dynamic range from the interlaced video input. Second, we jointly solve the denoising problem by tailoring sparse coding to better handle additive noise in low-/high-exposure rows, and also adopt multiscale homography flow to temporal sequences for denoising. We anticipate that the proposed method will allow for concurrent capture of higher dynamic range video frames without suffering from ghosting artifacts. We demonstrate the advantages of our interlaced video imaging compared with the state-of-the-art high-dynamic-range video methods.

  18. Image Reconstruction from Highly Undersampled (k, t)-Space Data with Joint Partial Separability and Sparsity Constraints

    PubMed Central

    Zhao, Bo; Haldar, Justin P.; Christodoulou, Anthony G.; Liang, Zhi-Pei

    2012-01-01

    Partial separability (PS) and sparsity have been previously used to enable reconstruction of dynamic images from undersampled (k, t)-space data. This paper presents a new method to use PS and sparsity constraints jointly for enhanced performance in this context. The proposed method combines the complementary advantages of PS and sparsity constraints using a unified formulation, achieving significantly better reconstruction performance than using either of these constraints individually. A globally convergent computational algorithm is described to efficiently solve the underlying optimization problem. Reconstruction results from simulated and in vivo cardiac MRI data are also shown to illustrate the performance of the proposed method. PMID:22695345

  19. Jointly reconstructing ground motion and resistivity for ERT-based slope stability monitoring

    NASA Astrophysics Data System (ADS)

    Boyle, Alistair; Wilkinson, Paul B.; Chambers, Jonathan E.; Meldrum, Philip I.; Uhlemann, Sebastian; Adler, Andy

    2018-02-01

    Electrical resistivity tomography (ERT) is increasingly being used to investigate unstable slopes and monitor the hydrogeological processes within. But movement of electrodes or incorrect placement of electrodes with respect to an assumed model can introduce significant resistivity artefacts into the reconstruction. In this work, we demonstrate a joint resistivity and electrode movement reconstruction algorithm within an iterative Gauss-Newton framework. We apply this to ERT monitoring data from an active slow-moving landslide in the UK. Results show fewer resistivity artefacts and suggest that electrode movement and resistivity can be reconstructed at the same time under certain conditions. A new 2.5-D formulation for the electrode position Jacobian is developed and is shown to give accurate numerical solutions when compared to the adjoint method on 3-D models. On large finite element meshes, the calculation time of the newly developed approach was also proven to be orders of magnitude faster than the 3-D adjoint method and addressed modelling errors in the 2-D perturbation and adjoint electrode position Jacobian.

  20. Arthroscopic treatment of acute acromioclavicular joint dislocation by coracoclavicular ligament augmentation.

    PubMed

    Liu, Xudong; Huangfu, Xiaoqiao; Zhao, Jinzhong

    2015-05-01

    Coracoclavicular (CC) ligament augmentation has been a method to treat acromioclavicular (AC) joint dislocation in recent years. The purpose of this paper is to describe our arthroscopic CC ligament augmentation technique in treating type III and V acute AC joint dislocations and to report the early clinical and radiological results. From 2010 to 2011, twelve patients suffering from acute type III or V AC joint dislocations were arthroscopically treated in our department, by CC ligament augmentation after AC joint reduction. The post-operative outcomes were assessed through physical examination, radiographic examination and the Constant-Murley Shoulder Score. All patients post-operatively experienced anatomical reduction in their AC joint dislocation. No intraoperative complications occurred. At a mean follow-up at 24 months (ranging from 18 to 32 months), the mean Constant-Murley Shoulder Score significantly improved from 24.3 pre-operatively to 91.1 post-operatively. No neurovascular complications or secondary degenerative changes of the AC joint were detected in any of the patients. In one case, a second dislocation occurred 1 month post-operation because the patient had had another traumatic injury. This patient accepted a revision operation, but his AC joint eventually fixated into a subluxated position after his second injury. Based on the resultant successful repair in all cases, the arthroscopic CC ligament augmentation method has thus far proven to be a safe and reliable technique for treatment of acute type III or V AC joint dislocation. The arthroscopic CC ligament augmentation with a flip button/polyethylene belt repair is an efficient method to treat acute type III and V AC joint dislocations which should be popularized. IV.

  1. Lateral ligament repair and reconstruction restore neither contact mechanics of the ankle joint nor motion patterns of the hindfoot.

    PubMed

    Prisk, Victor R; Imhauser, Carl W; O'Loughlin, Padhraig F; Kennedy, John G

    2010-10-20

    Ankle sprains may damage both the lateral ligaments of the hindfoot and the osteochondral tissue of the ankle joint. When nonoperative treatment fails, operative approaches are indicated to restore both native motion patterns at the hindfoot and ankle joint contact mechanics. The goal of the present study was to determine the effect of lateral ligament injury, repair, and reconstruction on ankle joint contact mechanics and hindfoot motion patterns. Eight cadaveric specimens were tested with use of robotic technology to apply combined compressive (200-N) and inversion (4.5-Nm) loads to the hindfoot at 0° and 20° of plantar flexion. Contact mechanics at the ankle joint were simultaneously measured. A repeated-measures experiment was designed with use of the intact condition as control, with the other conditions including sectioned anterior talofibular and calcaneofibular ligaments, the Broström and Broström-Gould repairs, and graft reconstruction. Ligament sectioning decreased contact area and caused a medial and anterior shift in the center of pressure with inversion loads relative to those with the intact condition. There were no significant differences in inversion or coupled axial rotation with inversion between the Broström repair and the intact condition; however, medial translation of the center of pressure remained elevated after the Broström repair relative to the intact condition. The Gould modification of the Broström procedure provided additional support to the hindfoot relative to the Broström repair, reducing inversion and axial rotation with inversion beyond that of intact ligaments. There were no significant differences in center-of-pressure excursion patterns between the Broström-Gould repair and the intact ligament condition, but this repair increased contact area beyond that with the ligaments intact. Graft reconstruction more closely restored inversion motion than did the Broström-Gould repair at 20° of plantar flexion but limited

  2. Outcomes and complications following graft reconstruction for anterior sternoclavicular joint instability.

    PubMed

    Willinger, Lukas; Schanda, Jakob; Herbst, Elmar; Imhoff, Andreas B; Martetschläger, Frank

    2016-12-01

    Publications describing tendon graft reconstruction for anterior sternoclavicular joint (SCJ) instability are rare and usually refer to small patient numbers. The aim of this study was to systematically review the literature regarding outcomes and complications following tendon graft reconstruction techniques for anterior SCJ instability. An online database was systematically searched to identify studies on graft reconstruction for anterior SCJ instability. Reported outcome scores were graded as excellent, good, fair and poor to summarize the study results. All reported complications were recorded. Five articles with a total of 80 patients met the inclusion criteria. Reported outcomes were excellent in 10 %, good in 89 % and fair in 1 %. Recurrent instability was found in 10 % of the patients, and 5 % underwent revision surgery due to persistent impairment of shoulder function related to SCJ instability or osteoarthritis. Surgical stabilization techniques for the SCJ using autologous tendon grafts have shown to be safe and reliable and make better patients' pain situation and shoulder function. However, a certain amount of impairment might persist, which needs to be discussed with patients. Severe complications were rare and revision rates were as low as 5 %. Therefore, graft reconstruction techniques should be considered for patients with chronic anterior SCJ instability after a course of failed conservative treatment. This study is valuable for clinicians in daily clinical practice when dealing with this difficult-to-treat pathology and can help surgeons to better predict the clinical outcomes and complications following SCJ graft reconstruction. It should, however, not lead to underestimation of the potential risks of the procedure. Systematic review, Level IV.

  3. Calculating the axes of rotation for the subtalar and talocrural joints using 3D bone reconstructions.

    PubMed

    Parr, W C H; Chatterjee, H J; Soligo, C

    2012-04-05

    Orientation of the subtalar joint axis dictates inversion and eversion movements of the foot and has been the focus of evolutionary and clinical studies for a number of years. Previous studies have measured the subtalar joint axis against the axis of the whole foot, the talocrural joint axis and, recently, the principal axes of the talus. The present study introduces a new method for estimating average joint axes from 3D reconstructions of bones and applies the method to the talus to calculate the subtalar and talocrural joint axes. The study also assesses the validity of the principal axes as a reference coordinate system against which to measure the subtalar joint axis. In order to define the angle of the subtalar joint axis relative to that of another axis in the talus, we suggest measuring the subtalar joint axis against the talocrural joint axis. We present corresponding 3D vector angles calculated from a modern human skeletal sample. This method is applicable to virtual 3D models acquired through surface-scanning of disarticulated 'dry' osteological samples, as well as to 3D models created from CT or MRI scans. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Acromioclavicular joint reconstruction by coracoid process transfer augmented with hook plate.

    PubMed

    Wang, Yeming; Zhang, Jianguo

    2014-06-01

    Various techniques have been reported for the treatment of chronic acromioclavicular (AC) joint separation. The purpose of this study was to evaluate the results of surgical construction of coracoclavicular ligament using coracoid process transfer augmented with a hook plate fixation. Twenty-one patients treated with coracoid process transfer augmented with a hook plate fixation for chronic type III and V AC injuries were retrospectively analysed in 2003-2009. The age of the patients ranged from 23 to 58 years with an average age of 41.6 years. The patients were followed up clinically and radiographically, with an average of 33.0 months. Functional status and the ability to return to work were recorded during follow-up. Constant score and visual analogue scale (VAS) for pain were measured. The mean Constant score has increased from 70.9 points preoperatively to 90.7 points at follow-up. The mean VAS score has decreased from 4.7 preoperatively to 1.2 at follow-up. The average abduction was 172°, forward flexion was 170° and external rotation was 56°. There were 10 excellent results, 10 good results and one fair result. All patients had resumed their job or returned to original sport activity at mean 3.7 months postoperatively. No reduction loss was observed after plate removal and the final follow-up. Despite retrospective nature of the study, the outcomes of surgical construction with process transfer augmented with hook plate fixation are promising for chronic type III and V AC injuries. Therapeutic level IV. Retrospective case series, treatment study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Combined arthroscopically assisted coraco- and acromioclavicular stabilization of acute high-grade acromioclavicular joint separations.

    PubMed

    Hann, Carmen; Kraus, Natascha; Minkus, Marvin; Maziak, Nina; Scheibel, Markus

    2018-01-01

    Due to high rate of persisting dynamic posterior translation (DPT) following isolated coracoclavicular double-button technique for reconstruction of the acromioclavicular (AC) joint reported in the literature, an additional acromioclavicular cerclage was added to the procedure. The aim of this study was to evaluate the clinical and radiological results of patients with high-grade AC-joint instability treated with a double TightRope technique with an additional percutaneous acromioclavicular cerclage. Fifty-nine patients (6 f/53 m; median age 38.3 (range 21.5-63.4 years) who sustained an acute high-grade AC-joint dislocation (Rockwood type V) were treated using the above-mentioned technique. At the final follow-up, the constant score (CS), the subjective shoulder value (SSV), the Taft score (TF) and the acromioclavicular joint instability score (ACJI) as well as bilateral anteroposterior stress views with 10 kg of axial load and bilateral modified Alexander views were obtained. At a median follow-up of 26.4 (range 20.3-61.0) months, 34 patients scored a median of 90 (33-100) points in the CS, 90 (25-100) % in the SSV, 11 (4-12) points in the TF and 87 (43-100) points in the ACJI. The coracoclavicular (CC) distance was 12.1 (6.5-19.8) mm and the CC difference 2.0 (0.0-11.0) mm. Two patients (5.8%) showed a complete DPT of the AC joint, and fourteen patients (41.1%) displayed a partial DPT. The overall revision rate was 11.7%. Two patients presented implant irritation, one patient a recurrent instability, and one patient suffered from a local infection. The arthroscopically assisted and image-intensifier-controlled double TightRope technique with an additional percutaneous acromioclavicular cerclage leads to good and excellent clinical results after a follow-up of 2 years. The incidence of persisting dynamic horizontal translation is lower compared to isolated coracoclavicular stabilization. Thus, we recommend using the double TightRope implant with an additional

  6. Skull Base Erosion Resulting From Primary Tumors of the Temporomandibular Joint and Skull Base Region: Our Classification and Reconstruction Experience.

    PubMed

    Chen, Min-Jie; Yang, Chi; Zheng, Ji-Si; Bai, Guo; Han, Zi-Xiang; Wang, Yi-Wen

    2018-06-01

    We sought to introduce our classification and reconstruction protocol for skull base erosions in the temporomandibular joint and skull base region. Patients with neoplasms in the temporomandibular joint and skull base region treated from January 2006 to March 2017 were reviewed. Skull base erosion was classified into 3 types according to the size of the defect. We included 33 patients, of whom 5 (15.2%) had type I defects (including 3 in whom free fat grafts were placed and 2 in whom deep temporal fascial fat flaps were placed). There were 8 patients (24.2%) with type II defects, all of whom received deep temporal fascial fat flaps. A total of 20 patients (60.6%) had type III defects, including 17 in whom autogenous bone grafts were placed, 1 in whom titanium mesh was placed, and 2 who received total alloplastic joints. The mean follow-up period was 50 months. All of the patients exhibited stable occlusion and good facial symmetry. No recurrence was noted. Our classification and reconstruction principles allowed reliable morpho-functional skull base reconstruction. Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  7. Lateral Ligament Repair and Reconstruction Restore Neither Contact Mechanics of the Ankle Joint nor Motion Patterns of the Hindfoot

    PubMed Central

    Prisk, Victor R.; Imhauser, Carl W.; O'Loughlin, Padhraig F.; Kennedy, John G.

    2010-01-01

    Background: Ankle sprains may damage both the lateral ligaments of the hindfoot and the osteochondral tissue of the ankle joint. When nonoperative treatment fails, operative approaches are indicated to restore both native motion patterns at the hindfoot and ankle joint contact mechanics. The goal of the present study was to determine the effect of lateral ligament injury, repair, and reconstruction on ankle joint contact mechanics and hindfoot motion patterns. Methods: Eight cadaveric specimens were tested with use of robotic technology to apply combined compressive (200-N) and inversion (4.5-Nm) loads to the hindfoot at 0° and 20° of plantar flexion. Contact mechanics at the ankle joint were simultaneously measured. A repeated-measures experiment was designed with use of the intact condition as control, with the other conditions including sectioned anterior talofibular and calcaneofibular ligaments, the Broström and Broström-Gould repairs, and graft reconstruction. Results: Ligament sectioning decreased contact area and caused a medial and anterior shift in the center of pressure with inversion loads relative to those with the intact condition. There were no significant differences in inversion or coupled axial rotation with inversion between the Broström repair and the intact condition; however, medial translation of the center of pressure remained elevated after the Broström repair relative to the intact condition. The Gould modification of the Broström procedure provided additional support to the hindfoot relative to the Broström repair, reducing inversion and axial rotation with inversion beyond that of intact ligaments. There were no significant differences in center-of-pressure excursion patterns between the Broström-Gould repair and the intact ligament condition, but this repair increased contact area beyond that with the ligaments intact. Graft reconstruction more closely restored inversion motion than did the Broström-Gould repair at 20° of

  8. [Custom-made implant for complex facial reconstruction: A case of total replacement of temporo-mandibular joint, zygomatic arch and malar bone].

    PubMed

    Guillier, D; Moris, V; See, L-A; Girodon, M; Wajszczak, B-L; Zwetyenga, N

    2017-02-01

    Total prosthetic replacement of the temporo-mandibular joint (TMJ) has become a common procedure, but it is usually limited to the TMJ itself. We report about one case of complex prosthetic joint reconstruction extending to the neighbouring bony structures. A 57-year-old patient, operated several times for a cranio-facial fibrous dysplasia, presented with a recurring TMJ ankylosis and a complexe latero-facial bone loss on the right side. We performed a reconstruction procedure including the TMJ, the zygomatic arch and the malar bone by mean of custom made composite prosthesis (chrome-cobalt-molybdenum-titanium and polyethylene). Five years postoperatively, mouth opening, nutrition, pain and oral hygiene were significantly improved. Nowadays technical possibilities allow for complex facial alloplastic reconstructions with good medium term results. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. An equilibrium-point model of electromyographic patterns during single-joint movements based on experimentally reconstructed control signals.

    PubMed

    Latash, M L; Goodman, S R

    1994-01-01

    The purpose of this work has been to develop a model of electromyographic (EMG) patterns during single-joint movements based on a version of the equilibrium-point hypothesis, a method for experimental reconstruction of the joint compliant characteristics, the dual-strategy hypothesis, and a kinematic model of movement trajectory. EMG patterns are considered emergent properties of hypothetical control patterns that are equally affected by the control signals and peripheral feedback reflecting actual movement trajectory. A computer model generated the EMG patterns based on simulated movement kinematics and hypothetical control signals derived from the reconstructed joint compliant characteristics. The model predictions have been compared to published recordings of movement kinematics and EMG patterns in a variety of movement conditions, including movements over different distances, at different speeds, against different-known inertial loads, and in conditions of possible unexpected decrease in the inertial load. Changes in task parameters within the model led to simulated EMG patterns qualitatively similar to the experimentally recorded EMG patterns. The model's predictive power compares it favourably to the existing models of the EMG patterns. Copyright © 1994. Published by Elsevier Ltd.

  10. Anatomical principles for minimally invasive reconstruction of the acromioclavicular joint with anchors.

    PubMed

    Xiong, Chuanzhi; Lu, Yaojia; Wang, Qiang; Chen, Gang; Hu, Hansheng; Lu, Zhihua

    2016-11-01

    The aim of this study was to evaluate the outcome of a minimally invasive surgical technique for the treatment of patients with acromioclavicular joint dislocation. Sixteen patients with complete acromioclavicular joint dislocation were enrolled in this study. All patients were asked to follow the less active rehabilitation protocol post-operatively. Computed tomography with 3-D reconstruction of the injured shoulder was performed on each patient post operatively for the assessment of the accuracy of the suture anchor placement in the coracoid process and the reduction of the acromioclavicular joint. Radiographs of Zanca view and axillary view of both shoulders were taken for evaluating the maintenance of the acromioclavicular joint reduction at each follow-up visit. The Constant shoulder score was used for function assessment at the final follow-up. Twenty seven of the 32 anchors implanted in the coracoid process met the criteria of good position. One patient developed complete loss of reduction and another had partial loss of reduction in the anteroposterior plane. For the other 14 patients, the mean Constant score was 90 (range, 82-95). For the patients with partial and complete loss of reduction, the Constant score were 92 and 76 respectively. All of them got nearly normal range of motion of the shoulders and restored to pre-operative life and works. With this minimally invasive approach and limited exposure of the coracoid, a surgeon can place the suture anchors at the anatomical insertions of the coracoclavicular ligament and allow the dislocated joint reduced and maintained well. Level IV, Case series; therapeutic study.

  11. dPIRPLE: a joint estimation framework for deformable registration and penalized-likelihood CT image reconstruction using prior images

    NASA Astrophysics Data System (ADS)

    Dang, H.; Wang, A. S.; Sussman, Marc S.; Siewerdsen, J. H.; Stayman, J. W.

    2014-09-01

    Sequential imaging studies are conducted in many clinical scenarios. Prior images from previous studies contain a great deal of patient-specific anatomical information and can be used in conjunction with subsequent imaging acquisitions to maintain image quality while enabling radiation dose reduction (e.g., through sparse angular sampling, reduction in fluence, etc). However, patient motion between images in such sequences results in misregistration between the prior image and current anatomy. Existing prior-image-based approaches often include only a simple rigid registration step that can be insufficient for capturing complex anatomical motion, introducing detrimental effects in subsequent image reconstruction. In this work, we propose a joint framework that estimates the 3D deformation between an unregistered prior image and the current anatomy (based on a subsequent data acquisition) and reconstructs the current anatomical image using a model-based reconstruction approach that includes regularization based on the deformed prior image. This framework is referred to as deformable prior image registration, penalized-likelihood estimation (dPIRPLE). Central to this framework is the inclusion of a 3D B-spline-based free-form-deformation model into the joint registration-reconstruction objective function. The proposed framework is solved using a maximization strategy whereby alternating updates to the registration parameters and image estimates are applied allowing for improvements in both the registration and reconstruction throughout the optimization process. Cadaver experiments were conducted on a cone-beam CT testbench emulating a lung nodule surveillance scenario. Superior reconstruction accuracy and image quality were demonstrated using the dPIRPLE algorithm as compared to more traditional reconstruction methods including filtered backprojection, penalized-likelihood estimation (PLE), prior image penalized-likelihood estimation (PIPLE) without registration, and

  12. PCC/AC shoulder joint seal evaluation

    DOT National Transportation Integrated Search

    1999-05-07

    This report presents the findings on the evaluation of Crafco Incorporated Roadsaver 903 SL Silicone Sealant and Dow Corning 890 SL Silicone Sealant. The Research Technical Panel had proposed to use the two self-leveling silicone joint sealants in te...

  13. Variance based joint sparsity reconstruction of synthetic aperture radar data for speckle reduction

    NASA Astrophysics Data System (ADS)

    Scarnati, Theresa; Gelb, Anne

    2018-04-01

    In observing multiple synthetic aperture radar (SAR) images of the same scene, it is apparent that the brightness distributions of the images are not smooth, but rather composed of complicated granular patterns of bright and dark spots. Further, these brightness distributions vary from image to image. This salt and pepper like feature of SAR images, called speckle, reduces the contrast in the images and negatively affects texture based image analysis. This investigation uses the variance based joint sparsity reconstruction method for forming SAR images from the multiple SAR images. In addition to reducing speckle, the method has the advantage of being non-parametric, and can therefore be used in a variety of autonomous applications. Numerical examples include reconstructions of both simulated phase history data that result in speckled images as well as the images from the MSTAR T-72 database.

  14. The ACS NSQIP Risk Calculator Is a Fair Predictor of Acute Periprosthetic Joint Infection.

    PubMed

    Wingert, Nathaniel C; Gotoff, James; Parrilla, Edgardo; Gotoff, Robert; Hou, Laura; Ghanem, Elie

    2016-07-01

    Periprosthetic joint infection (PJI) is a severe complication from the patient's perspective and an expensive one in a value-driven healthcare model. Risk stratification can help identify those patients who may have risk factors for complications that can be mitigated in advance of elective surgery. Although numerous surgical risk calculators have been created, their accuracy in predicting outcomes, specifically PJI, has not been tested. (1) How accurate is the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Surgical Site Infection Calculator in predicting 30-day postoperative infection? (2) How accurate is the calculator in predicting 90-day postoperative infection? We isolated 1536 patients who underwent 1620 primary THAs and TKAs at our institution during 2011 to 2013. Minimum followup was 90 days. The ACS NSQIP Surgical Risk Calculator was assessed in its ability to predict acute PJI within 30 and 90 days postoperatively. Patients who underwent a repeat surgical procedure within 90 days of the index arthroplasty and in whom at least one positive intraoperative culture was obtained at time of reoperation were considered to have PJI. A total of 19 cases of PJI were identified, including 11 at 30 days and an additional eight instances by 90 days postoperatively. Patient-specific risk probabilities for PJI based on demographics and comorbidities were recorded from the ACS NSQIP Surgical Risk Calculator website. The area under the curve (AUC) for receiver operating characteristic (ROC) curves was calculated to determine the predictability of the risk probability for PJI. The AUC is an effective method for quantifying the discriminatory capacity of a diagnostic test to correctly classify patients with and without infection in which it is defined as excellent (AUC 0.9-1), good (AUC 0.8-0.89), fair (AUC 0.7-0.79), poor (AUC 0.6-0.69), or fail/no discriminatory capacity (AUC 0.5-0.59). A p value of < 0.05 was considered to be

  15. Autologous temporomandibular joint reconstruction independent of exogenous additives: a proof-of-concept study for guided self-generation.

    PubMed

    Wei, Jiao; Herrler, Tanja; Han, Dong; Liu, Kai; Huang, Rulin; Guba, Markus; Dai, Chuanchang; Li, Qingfeng

    2016-11-28

    Joint defects are complex and difficult to reconstruct. By exploiting the body's own regenerative capacity, we aimed to individually generate anatomically precise neo-tissue constructs for autologous joint reconstruction without using any exogenous additives. In a goat model, CT scans of the mandibular condyle including articular surface and a large portion of the ascending ramus were processed using computer-aided design and manufacturing. A corresponding hydroxylapatite negative mold was printed in 3D and temporarily embedded into the transition zone of costal periosteum and perichondrium. A demineralized bone matrix scaffold implanted on the contralateral side served as control. Neo-tissue constructs obtained by guided self-generation exhibited accurate configuration, robust vascularization, biomechanical stability, and function. After autologous replacement surgery, the constructs showed stable results with similar anatomical, histological, and functional findings compared to native controls. Further studies are required to assess long-term outcome and possible extensions to other further applications. The absence of exogenous cells, growth factors, and scaffolds may facilitate clinical translation of this approach.

  16. Anatomical frame identification and reconstruction for repeatable lower limb joint kinematics estimates.

    PubMed

    Donati, Marco; Camomilla, Valentina; Vannozzi, Giuseppe; Cappozzo, Aurelio

    2008-07-19

    The quantitative description of joint mechanics during movement requires the reconstruction of the position and orientation of selected anatomical axes with respect to a laboratory reference frame. These anatomical axes are identified through an ad hoc anatomical calibration procedure and their position and orientation are reconstructed relative to bone-embedded frames normally derived from photogrammetric marker positions and used to describe movement. The repeatability of anatomical calibration, both within and between subjects, is crucial for kinematic and kinetic end results. This paper illustrates an anatomical calibration approach, which does not require anatomical landmark manual palpation, described in the literature to be prone to great indeterminacy. This approach allows for the estimate of subject-specific bone morphology and automatic anatomical frame identification. The experimental procedure consists of digitization through photogrammetry of superficial points selected over the areas of the bone covered with a thin layer of soft tissue. Information concerning the location of internal anatomical landmarks, such as a joint center obtained using a functional approach, may also be added. The data thus acquired are matched with the digital model of a deformable template bone. Consequently, the repeatability of pelvis, knee and hip joint angles is determined. Five volunteers, each of whom performed five walking trials, and six operators, with no specific knowledge of anatomy, participated in the study. Descriptive statistics analysis was performed during upright posture, showing a limited dispersion of all angles (less than 3 deg) except for hip and knee internal-external rotation (6 deg and 9 deg, respectively). During level walking, the ratio of inter-operator and inter-trial error and an absolute subject-specific repeatability were assessed. For pelvic and hip angles, and knee flexion-extension the inter-operator error was equal to the inter-trial error

  17. Reconstructing for joint angles on the shoulder and elbow from non-invasive electroencephalographic signals through electromyography

    PubMed Central

    Choi, Kyuwan

    2013-01-01

    In this study, first the cortical activities over 2240 vertexes on the brain were estimated from 64 channels electroencephalography (EEG) signals using the Hierarchical Bayesian estimation while 5 subjects did continuous arm reaching movements. From the estimated cortical activities, a sparse linear regression method selected only useful features in reconstructing the electromyography (EMG) signals and estimated the EMG signals of 9 arm muscles. Then, a modular artificial neural network was used to estimate four joint angles from the estimated EMG signals of 9 muscles: one for movement control and the other for posture control. The estimated joint angles using this method have the correlation coefficient (CC) of 0.807 (±0.10) and the normalized root-mean-square error (nRMSE) of 0.176 (±0.29) with the actual joint angles. PMID:24167469

  18. A joint Richardson—Lucy deconvolution algorithm for the reconstruction of multifocal structured illumination microscopy data

    NASA Astrophysics Data System (ADS)

    Ströhl, Florian; Kaminski, Clemens F.

    2015-03-01

    We demonstrate the reconstruction of images obtained by multifocal structured illumination microscopy, MSIM, using a joint Richardson-Lucy, jRL-MSIM, deconvolution algorithm, which is based on an underlying widefield image-formation model. The method is efficient in the suppression of out-of-focus light and greatly improves image contrast and resolution. Furthermore, it is particularly well suited for the processing of noise corrupted data. The principle is verified on simulated as well as experimental data and a comparison of the jRL-MSIM approach with the standard reconstruction procedure, which is based on image scanning microscopy, ISM, is made. Our algorithm is efficient and freely available in a user friendly software package.

  19. Imaging ac losses in superconducting films via scanning Hall probe microscopy

    NASA Astrophysics Data System (ADS)

    Dinner, Rafael B.; Moler, Kathryn A.; Feldmann, D. Matthew; Beasley, M. R.

    2007-04-01

    Various local probes have been applied to understanding current flow through superconducting films, which are often surprisingly inhomogeneous. Here, we show that magnetic imaging allows quantitative reconstruction of both current density J and electric field E resolved in time and space in a film carrying subcritical ac current. Current reconstruction entails inversion of the Biot-Savart law, while electric fields are reconstructed using Faraday’s law. We describe the corresponding numerical procedures, largely adapting existing work to the case of a strip carrying ac current, but including other methods of obtaining the complete electric field from the inductive portion determined by Faraday’s law. We also delineate the physical requirements behind the mathematical transformations. We then apply the procedures to images of a strip of YBa2Cu3O7-δ carrying an ac current at 400Hz . Our scanning Hall probe microscope produces a time series of magnetic images of the strip with 1μm spatial resolution and 25μs time resolution. Combining the reconstructed J and E , we obtain a complete characterization including local critical current density, E-J curves, and power losses. This analysis has a range of applications from fundamental studies of vortex dynamics to practical coated conductor development.

  20. [Treatment of complete acromioclavicular joint dislocation with transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament].

    PubMed

    Dong, Wen-Wei; Shi, Zeng-Yuan; Liu, Zheng-Xin; Mao, Hai-Jiao

    2015-04-01

    To explore the operation methods and clinical effects of transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament in treating complete acromioclavicular joint dislocation. From January 2006 to June 2012,26 patients with acute complete acromioclavicular joint dislocation underwent surgery. Transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament, additional clavical hoot plate and Kirschner wires fixation, were performed in all the patients. Among the patients, 18 patients were male and 8 patients were female, with an average age of 36.7 years old (ranged from 25 to 51 years). The duration from injury to operation was from 3 to 12 days with an average of 5 days. According to the Rockwood classification, 4 cases were grade III and 22 cases were grade V . Clinical manifestation included local swelling, tenderness with snapping, limitation of shoulder joint motion. In preoperative bilateral shoulder joint X-rays, the injured coracoclavicular distance was (16.2 ± 5.0) mm which was significantly wider than that of uninjured sides (7.6 ± 1.0) mm. Clinical results were evaluated according to X-rays and Constant-Murley score. All incisions obtained primary healing after operation without complication of infection, internal fixation breakage, redislocation. All the patients were followed up from 12 to 30 months with an average of 18 months. Kirschner wires and internal fixation plate were removed at 1 month and 8-10 months after operation, respectively. At final follow-up, the motion of shoulder joint recovered to normal and a no pain joint was obtained. According to Constant-Murley score, 24 cases got excellent results and 2 cases good. There was no significant difference after operation between the injured coracoclavicular distance and the uninjured contralateral side [(7.7 ± 1.2) mm vs (7.6 ± 1.0) mm), P > 0.05]. Transfer of the medial half of the coracoacromial ligament to

  1. Resident accuracy of joint line palpation using ultrasound verification.

    PubMed

    Rho, Monica E; Chu, Samuel K; Yang, Aaron; Hameed, Farah; Lin, Cindy Yuchin; Hurh, Peter J

    2014-10-01

    To determine the accuracy of knee and acromioclavicular (AC) joint line palpation in Physical Medicine and Rehabilitation (PM&R) residents using ultrasound (US) verification. Cohort study. PM&R residency program at an academic institution. Twenty-four PM&R residents participating in a musculoskeletal US course (7 PGY-2, 8 PGY-3, and 9 PGY4 residents). Twenty-four PM&R residents participating in an US course were asked to palpate the AC joint and lateral joint line of the knee in a female and male model before the start of the course. Once the presumed joint line was localized, the residents were asked to tape an 18-gauge, 1.5-inch, blunt-tip needle parallel to the joint line on the overlying skin. The accuracy of needle placement over the joint line was verified using US. US verification of correct needle placement over the joint line. Overall AC joint palpation accuracy was 16.7%, and knee lateral joint line palpation accuracy was 58.3%. Based on the resident level of education, using a value of P < .05, there were no statistically significant differences in the accuracy of joint line palpation. Residents in this study demonstrate poor accuracy of AC joint and lateral knee joint line identification by palpation, using US as the criterion standard for verification. There were no statistically significant differences in the accuracy rates of joint line palpation based on resident level of education. US may be a useful tool to use to advance the current methods of teaching the physical examination in medical education. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  2. Acromioclavicular Joint Dislocation with Ipsilateral Mid Third Clavicle, Mid Shaft Humerus and Coracoid Process Fracture - A Case Report.

    PubMed

    Sharma, Naveen; Mandloi, Avinash; Agrawal, Ashish; Singh, Shailendra

    2016-01-01

    The clavicle, humerus and acromioclavicular (AC) joint separately are very commonly involved in traumatic injuries around the shoulder. Acromioclavicular joint dislocation with distal clavicle fracture is a well recognized entity in clinical practice. AC joint dislocation with mid shaft clavicle fracture is uncommon and only few cases have been reported in literature. However, to the best of our knowledge, this is the first case report to describe an acromioclavicular dislocation with ipsilateral mid shaft clavicle, mid shaft humerus and coracoid process fracture. Fractures of the humerus and clavicle along with the acromioclavicular joint dislocation were fixed at the same setting. A 65-year-old male met with a high velocity road traffic accident. Plain radiographs showed displaced mid third clavicle fracture with acromioclavicular joint dislocation with mid shaft humerus fracture. Surgical fixation was planned for humerus with interlocking nail, clavicle with locking plate and acromioclavicular joint with reconstruction of coracoclavicular ligaments. Intraoperatively, coracoid process was found to have a comminuted fracture. The operative plan had to be changed on table as coracoclavicular fixation was not possible. So acromioclavicular joint fixation was done using tension band wiring and the coracoclavicular ligament was repaired using a 2-0 ethibond. The comminuted coracoid fracture was managed conservatively. K wires were removed at 6 weeks. Early mobilization was started. In acromioclavicular joint injuries, clavicle must be evaluated for any injury. Although it is more commonly associated with distal clavicle fractures, it can be associated with middle third clavicle fractures. As plain radiographs, AP view are most of the times insufficient for viewing integrity of coracoid process, either special views like Stryker notch or CT scan may help in diagnosing such concealed injuries. When associated with fractures of the humerus and clavicle, anatomical

  3. Extended hybrid-space SENSE for EPI: Off-resonance and eddy current corrected joint interleaved blip-up/down reconstruction.

    PubMed

    Zahneisen, Benjamin; Aksoy, Murat; Maclaren, Julian; Wuerslin, Christian; Bammer, Roland

    2017-06-01

    Geometric distortions along the phase encode direction caused by off-resonant spins are still a major issue in EPI based functional and diffusion imaging. If the off-resonance map is known it is possible to correct for distortions. Most correction methods operate as a post-processing step on the reconstructed magnitude images. Here, we present an algebraic reconstruction method (hybrid-space SENSE) that incorporates a physics based model of off-resonances, phase inconsistencies between k-space segments, and T2*-decay during the acquisition. The method can be used to perform a joint reconstruction of interleaved acquisitions with normal (blip-up) and inverted (blip-down) phase encode direction which results in reduced g-factor penalty. A joint blip-up/down simultaneous multi slice (SMS) reconstruction for SMS-factor 4 in combination with twofold in-plane acceleration leads to a factor of two decrease in maximum g-factor penalty while providing off-resonance and eddy-current corrected images. We provide an algebraic framework for reconstructing diffusion weighted EPI data that in addition to the general applicability of hybrid-space SENSE to 2D-EPI, SMS-EPI and 3D-EPI with arbitrary k-space coverage along z, allows for a modeling of arbitrary spatio-temporal effects during the acquisition period like off-resonances, phase inconsistencies and T2*-decay. The most immediate benefit is a reduction in g-factor penalty if an interleaved blip-up/down acquisition strategy is chosen which facilitates eddy current estimation and ensures no loss in k-space encoding in regions with strong off-resonance gradients. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Autologous temporomandibular joint reconstruction independent of exogenous additives: a proof-of-concept study for guided self-generation

    PubMed Central

    Wei, Jiao; Herrler, Tanja; Han, Dong; Liu, Kai; Huang, Rulin; Guba, Markus; Dai, Chuanchang; Li, Qingfeng

    2016-01-01

    Joint defects are complex and difficult to reconstruct. By exploiting the body’s own regenerative capacity, we aimed to individually generate anatomically precise neo-tissue constructs for autologous joint reconstruction without using any exogenous additives. In a goat model, CT scans of the mandibular condyle including articular surface and a large portion of the ascending ramus were processed using computer-aided design and manufacturing. A corresponding hydroxylapatite negative mold was printed in 3D and temporarily embedded into the transition zone of costal periosteum and perichondrium. A demineralized bone matrix scaffold implanted on the contralateral side served as control. Neo-tissue constructs obtained by guided self-generation exhibited accurate configuration, robust vascularization, biomechanical stability, and function. After autologous replacement surgery, the constructs showed stable results with similar anatomical, histological, and functional findings compared to native controls. Further studies are required to assess long-term outcome and possible extensions to other further applications. The absence of exogenous cells, growth factors, and scaffolds may facilitate clinical translation of this approach. PMID:27892493

  5. A joint Richardson-Lucy deconvolution algorithm for the reconstruction of multifocal structured illumination microscopy data.

    PubMed

    Ströhl, Florian; Kaminski, Clemens F

    2015-01-16

    We demonstrate the reconstruction of images obtained by multifocal structured illumination microscopy, MSIM, using a joint Richardson-Lucy, jRL-MSIM, deconvolution algorithm, which is based on an underlying widefield image-formation model. The method is efficient in the suppression of out-of-focus light and greatly improves image contrast and resolution. Furthermore, it is particularly well suited for the processing of noise corrupted data. The principle is verified on simulated as well as experimental data and a comparison of the jRL-MSIM approach with the standard reconstruction procedure, which is based on image scanning microscopy, ISM, is made. Our algorithm is efficient and freely available in a user friendly software package.

  6. Ligament reconstruction with single bone tunnel technique for chronic symptomatic subtle injury of the Lisfranc joint in athletes.

    PubMed

    Miyamoto, Wataru; Takao, Masato; Innami, Ken; Miki, Shinya; Matsushita, Takashi

    2015-08-01

    Only few procedures for Lisfranc ligaments reconstruction to treat subtle injury of the Lisfranc joint have been reported. We have developed a novel technique for Lisfranc ligaments reconstruction, which was applied to treat chronic symptomatic subtle injuries that had failed to respond to initial treatment or were misdiagnosed. This article describes the technique and its operative outcome in a small case series. Between April 2011 and October 2013, 5 (4 male and 1 female) athletes with a mean age of 19.4 (range 17-21) years were diagnosed with chronic subtle injury of the Lisfranc joint and underwent our novel reconstructive operation. In this technique, only a bone tunnel between the medial cuneiform and the second metatarsal bone is needed for near-anatomical reconstruction of the dorsal and interosseous ligaments. All patients were evaluated before and at 1 year after surgery using the American Orthopaedic Foot and Ankle Society (AOFAS) scale for the ankle-midfoot. In addition, the interval between surgery and return to athletic activity, defined as return to near pre-injury performance level, was investigated. Mean duration of postoperative follow-up was 18.8 (range 12-26) months. Mean AOFAS score improved significantly from 74.6 ± 2.5 (range 71-77) preoperatively to 96.0 ± 5.5 (range 90-100) at 1 year after the operation (p < 0.01). All patients were able to return to their previous athletic activities and the interval between surgery and return to athletic activity was 16.8 ± 1.1 (range 15-18) weeks. There was no complication related to the operation. The results of this study suggest that our technique of Lisfranc ligaments reconstruction using autologous graft is effective for athletes with chronic subtle injury. Level IV, retrospective case series.

  7. Anatomy assisted PET image reconstruction incorporating multi-resolution joint entropy

    NASA Astrophysics Data System (ADS)

    Tang, Jing; Rahmim, Arman

    2015-01-01

    A promising approach in PET image reconstruction is to incorporate high resolution anatomical information (measured from MR or CT) taking the anato-functional similarity measures such as mutual information or joint entropy (JE) as the prior. These similarity measures only classify voxels based on intensity values, while neglecting structural spatial information. In this work, we developed an anatomy-assisted maximum a posteriori (MAP) reconstruction algorithm wherein the JE measure is supplied by spatial information generated using wavelet multi-resolution analysis. The proposed wavelet-based JE (WJE) MAP algorithm involves calculation of derivatives of the subband JE measures with respect to individual PET image voxel intensities, which we have shown can be computed very similarly to how the inverse wavelet transform is implemented. We performed a simulation study with the BrainWeb phantom creating PET data corresponding to different noise levels. Realistically simulated T1-weighted MR images provided by BrainWeb modeling were applied in the anatomy-assisted reconstruction with the WJE-MAP algorithm and the intensity-only JE-MAP algorithm. Quantitative analysis showed that the WJE-MAP algorithm performed similarly to the JE-MAP algorithm at low noise level in the gray matter (GM) and white matter (WM) regions in terms of noise versus bias tradeoff. When noise increased to medium level in the simulated data, the WJE-MAP algorithm started to surpass the JE-MAP algorithm in the GM region, which is less uniform with smaller isolated structures compared to the WM region. In the high noise level simulation, the WJE-MAP algorithm presented clear improvement over the JE-MAP algorithm in both the GM and WM regions. In addition to the simulation study, we applied the reconstruction algorithms to real patient studies involving DPA-173 PET data and Florbetapir PET data with corresponding T1-MPRAGE MRI images. Compared to the intensity-only JE-MAP algorithm, the WJE

  8. Marker-based reconstruction of the kinematics of a chain of segments: a new method that incorporates joint kinematic constraints.

    PubMed

    Klous, Miriam; Klous, Sander

    2010-07-01

    The aim of skin-marker-based motion analysis is to reconstruct the motion of a kinematical model from noisy measured motion of skin markers. Existing kinematic models for reconstruction of chains of segments can be divided into two categories: analytical methods that do not take joint constraints into account and numerical global optimization methods that do take joint constraints into account but require numerical optimization of a large number of degrees of freedom, especially when the number of segments increases. In this study, a new and largely analytical method for a chain of rigid bodies is presented, interconnected in spherical joints (chain-method). In this method, the number of generalized coordinates to be determined through numerical optimization is three, irrespective of the number of segments. This new method is compared with the analytical method of Veldpaus et al. [1988, "A Least-Squares Algorithm for the Equiform Transformation From Spatial Marker Co-Ordinates," J. Biomech., 21, pp. 45-54] (Veldpaus-method, a method of the first category) and the numerical global optimization method of Lu and O'Connor [1999, "Bone Position Estimation From Skin-Marker Co-Ordinates Using Global Optimization With Joint Constraints," J. Biomech., 32, pp. 129-134] (Lu-method, a method of the second category) regarding the effects of continuous noise simulating skin movement artifacts and regarding systematic errors in joint constraints. The study is based on simulated data to allow a comparison of the results of the different algorithms with true (noise- and error-free) marker locations. Results indicate a clear trend that accuracy for the chain-method is higher than the Veldpaus-method and similar to the Lu-method. Because large parts of the equations in the chain-method can be solved analytically, the speed of convergence in this method is substantially higher than in the Lu-method. With only three segments, the average number of required iterations with the chain

  9. Relationship between patellar mobility and patellofemoral joint cartilage degeneration after anterior cruciate ligament reconstruction.

    PubMed

    Ota, Susumu; Kurokouchi, Kazutoshi; Takahashi, Shigeo; Yoda, Masaki; Yamamoto, Ryuichiro; Sakai, Tadahiro

    2017-11-01

    Patellofemoral cartilage degeneration is a potential complication of anterior cruciate ligament reconstruction (ACLR) surgery. Hypomobility of the patella in the coronal plane is often observed after ACLR. Few studies, however, have examined the relationship between cartilage degeneration in the patellofemoral joint and mobility after ACLR. The present study investigated 1) the coronal mobility of the patella after ACLR, 2) the relationship between patellar mobility and cartilage degeneration of the patellofemoral joint, and 3) the relationship between patellar mobility and knee joint function after ACLR. Forty patients who underwent medial hamstring-based ACLR participated in the study. Lateral and medial patellar displacements were assessed with a modified patellofemoral arthrometer, and the absolute values of the displacements were normalized to patient height. The International Cartilage Repair Society (ICRS) cartilage injury classification of the patellar and femoral (trochlear) surfaces, and the Lysholm Knee Scoring Scale were used to evaluate knee function. Lateral and medial patellar displacements were reduced compared with the non-operated knee at the second-look arthroscopy and bone staple extraction operation (second operation; 24.4 ± 7.9 months after ACLR, P<0.01). The ICRS grades of the patellofemoral joint (patella and trochlea) were significantly worse than those pre-ACLR. Neither lateral nor medial patellar mobility, however, were significantly correlated with the ICRS grade or the Lysholm score. Although patellar mobility at approximately 2 years after ACLR was decreased compared to the non-operated knee, small displacement of the patella was not related to cartilage degeneration or knee joint function at the time of the second operation.

  10. Rapid alignment of nanotomography data using joint iterative reconstruction and reprojection.

    PubMed

    Gürsoy, Doğa; Hong, Young P; He, Kuan; Hujsak, Karl; Yoo, Seunghwan; Chen, Si; Li, Yue; Ge, Mingyuan; Miller, Lisa M; Chu, Yong S; De Andrade, Vincent; He, Kai; Cossairt, Oliver; Katsaggelos, Aggelos K; Jacobsen, Chris

    2017-09-18

    As x-ray and electron tomography is pushed further into the nanoscale, the limitations of rotation stages become more apparent, leading to challenges in the alignment of the acquired projection images. Here we present an approach for rapid post-acquisition alignment of these projections to obtain high quality three-dimensional images. Our approach is based on a joint estimation of alignment errors, and the object, using an iterative refinement procedure. With simulated data where we know the alignment error of each projection image, our approach shows a residual alignment error that is a factor of a thousand smaller, and it reaches the same error level in the reconstructed image in less than half the number of iterations. We then show its application to experimental data in x-ray and electron nanotomography.

  11. The natural limb is best: joint preservation and reconstruction by distraction osteogenesis for high-grade juxta-articular osteosarcomas.

    PubMed

    Tsuchiya, Hiroyuki; Abdel-Wanis, Mohamed E; Kitano, Shinji; Sakurakichi, Keisuke; Yamashiro, Teruhisa; Tomita, Katsuro

    2002-01-01

    This paper introduces an innovative technique of highly conservative limb-saving surgery for juxta-articular osteosarcoma. This technique consists of marginal tumour excision, joint preservation and reconstruction by distraction osteogenesis. Ten patients, with a mean age of 19.5 years and high-grade osteosarcoma, underwent this procedure. The distal femur and proximal tibia were affected in five patients each. After effective pre-operative chemotherapy, the tumour was excised with preservation of the epiphysis, the articular surface and the maximun amount of healthy soft tissue. This was followed by application of an external fixator. Bone transport was performed for seven patients and shortening-distraction for three. The limb function was rated excellent in seven patients, good in one and fair in two. At the final follow-up, three patients were dead after a mean of 25.3 months while seven patients remained free of disease with a mean follow-up of 55.4 months. Joint preservation and biological reconstruction through distraction osteogenesis can produce excellent and long-lasting functional results.

  12. Geared Electromechanical Rotary Joint

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1994-01-01

    Geared rotary joint provides low-noise ac or dc electrical contact between electrical subsystems rotating relative to each other. Designed to overcome some disadvantages of older electromechanical interfaces, especially intermittency of sliding-contact and rolling-contact electromechanical joints. Hollow, springy planetary gears provide continuous, redundant, low-noise electrical contact between inner and outer gears.

  13. Joint reconstruction of x-ray fluorescence and transmission tomography

    DOE PAGES

    Di, Zichao; Chen, Si; Hong, Young Pyo; ...

    2017-05-30

    X-ray fluorescence tomography is based on the detection of fluorescence x-ray photons produced following x-ray absorption while a specimen is rotated; it provides information on the 3D distribution of selected elements within a sample. One limitation in the quality of sample recovery is the separation of elemental signals due to the finite energy resolution of the detector. Another limitation is the effect of self-absorption, which can lead to inaccurate results with dense samples. To recover a higher quality elemental map, we combine x-ray fluorescence detection with a second data modality: conventional x-ray transmission tomography using absorption. By using these combinedmore » signals in a nonlinear optimization-based approach, we demonstrate the benefit of our algorithm on real experimental data and obtain an improved quantitative reconstruction of the spatial distribution of dominant elements in the sample. Furthermore, compared with single-modality inversion based on x-ray fluorescence alone, this joint inversion approach reduces ill-posedness and should result in improved elemental quantification and better correction of self-absorption.« less

  14. Joint reconstruction of x-ray fluorescence and transmission tomography

    PubMed Central

    Di, Zichao Wendy; Chen, Si; Hong, Young Pyo; Jacobsen, Chris; Leyffer, Sven; Wild, Stefan M.

    2017-01-01

    X-ray fluorescence tomography is based on the detection of fluorescence x-ray photons produced following x-ray absorption while a specimen is rotated; it provides information on the 3D distribution of selected elements within a sample. One limitation in the quality of sample recovery is the separation of elemental signals due to the finite energy resolution of the detector. Another limitation is the effect of self-absorption, which can lead to inaccurate results with dense samples. To recover a higher quality elemental map, we combine x-ray fluorescence detection with a second data modality: conventional x-ray transmission tomography using absorption. By using these combined signals in a nonlinear optimization-based approach, we demonstrate the benefit of our algorithm on real experimental data and obtain an improved quantitative reconstruction of the spatial distribution of dominant elements in the sample. Compared with single-modality inversion based on x-ray fluorescence alone, this joint inversion approach reduces ill-posedness and should result in improved elemental quantification and better correction of self-absorption. PMID:28788848

  15. Joint reconstruction of the initial pressure and speed of sound distributions from combined photoacoustic and ultrasound tomography measurements

    NASA Astrophysics Data System (ADS)

    Matthews, Thomas P.; Anastasio, Mark A.

    2017-12-01

    The initial pressure and speed of sound (SOS) distributions cannot both be stably recovered from photoacoustic computed tomography (PACT) measurements alone. Adjunct ultrasound computed tomography (USCT) measurements can be employed to estimate the SOS distribution. Under the conventional image reconstruction approach for combined PACT/USCT systems, the SOS is estimated from the USCT measurements alone and the initial pressure is estimated from the PACT measurements by use of the previously estimated SOS. This approach ignores the acoustic information in the PACT measurements and may require many USCT measurements to accurately reconstruct the SOS. In this work, a joint reconstruction method where the SOS and initial pressure distributions are simultaneously estimated from combined PACT/USCT measurements is proposed. This approach allows accurate estimation of both the initial pressure distribution and the SOS distribution while requiring few USCT measurements.

  16. A concise evidence-based physical examination for diagnosis of acromioclavicular joint pathology: a systematic review.

    PubMed

    Krill, Michael K; Rosas, Samuel; Kwon, KiHyun; Dakkak, Andrew; Nwachukwu, Benedict U; McCormick, Frank

    2018-02-01

    The clinical examination of the shoulder joint is an undervalued diagnostic tool for evaluating acromioclavicular (AC) joint pathology. Applying evidence-based clinical tests enables providers to make an accurate diagnosis and minimize costly imaging procedures and potential delays in care. The purpose of this study was to create a decision tree analysis enabling simple and accurate diagnosis of AC joint pathology. A systematic review of the Medline, Ovid and Cochrane Review databases was performed to identify level one and two diagnostic studies evaluating clinical tests for AC joint pathology. Individual test characteristics were combined in series and in parallel to improve sensitivities and specificities. A secondary analysis utilized subjective pre-test probabilities to create a clinical decision tree algorithm with post-test probabilities. The optimal special test combination to screen and confirm AC joint pathology combined Paxinos sign and O'Brien's Test, with a specificity of 95.8% when performed in series; whereas, Paxinos sign and Hawkins-Kennedy Test demonstrated a sensitivity of 93.7% when performed in parallel. Paxinos sign and O'Brien's Test demonstrated the greatest positive likelihood ratio (2.71); whereas, Paxinos sign and Hawkins-Kennedy Test reported the lowest negative likelihood ratio (0.35). No combination of special tests performed in series or in parallel creates more than a small impact on post-test probabilities to screen or confirm AC joint pathology. Paxinos sign and O'Brien's Test is the only special test combination that has a small and sometimes important impact when used both in series and in parallel. Physical examination testing is not beneficial for diagnosis of AC joint pathology when pretest probability is unequivocal. In these instances, it is of benefit to proceed with procedural tests to evaluate AC joint pathology. Ultrasound-guided corticosteroid injections are diagnostic and therapeutic. An ultrasound-guided AC joint

  17. Cytokine mRNA expression in synovial fluid of affected and contralateral stifle joints and the left shoulder joint in dogs with unilateral disease of the stifle joint.

    PubMed

    de Bruin, Tanya; de Rooster, Hilde; van Bree, Henri; Duchateau, Luc; Cox, Eric

    2007-09-01

    To examine mRNA expression of cytokines in synovial fluid (SF) cells from dogs with cranial cruciate ligament (CrCL) rupture and medial patellar luxation (MPL) and determine mRNA expression for 3 joints (affected stifle, unaffected contralateral stifle, and left shoulder joints) in dogs with unilateral CrCL rupture. 29 stifle joints with CrCL rupture (29 dogs), 8 stifle joints with MPL (7 dogs), and 24 normal stifle joints (16 clinically normal dogs). Immediately before reconstructive surgery, SF was aspirated from the cruciate-deficient stifle joint or stifle joint with MPL. Fourteen of 29 dogs had unilateral CrCL rupture; SF was also aspirated from the unaffected contralateral stifle joint and left shoulder joint. Those 14 dogs were examined 6 and 12 months after reconstructive surgery. Total RNA was extracted from SF cells and reverse transcription-PCR assay was performed to obtain cDNA. Canine-specific cytokine mRNA expression was determined by use of a real-time PCR assay. Interleukin (IL)-8 and -10 and interferon-gamma expression differed significantly between dogs with arthropathies and dogs with normal stifle joints. For the 14 dogs with unilateral CrCL rupture, a significant difference was found for IL-8 expression. Before reconstructive surgery, IL-8 expression differed significantly between the affected stifle joint and left shoulder joint or contralateral stifle joint. Six months after surgery, IL-8 expression was significantly increased in the unaffected contralateral stifle joint, compared with the shoulder joint. No conclusions can be made regarding the role of the examined cytokines in initiation of CrCL disease.

  18. Mixture model based joint-MAP reconstruction of attenuation and activity maps in TOF-PET

    NASA Astrophysics Data System (ADS)

    Hemmati, H.; Kamali-Asl, A.; Ghafarian, P.; Ay, M. R.

    2018-06-01

    A challenge to have quantitative positron emission tomography (PET) images is to provide an accurate and patient-specific photon attenuation correction. In PET/MR scanners, the nature of MR signals and hardware limitations have led to a real challenge on the attenuation map extraction. Except for a constant factor, the activity and attenuation maps from emission data on TOF-PET system can be determined by the maximum likelihood reconstruction of attenuation and activity approach (MLAA) from emission data. The aim of the present study is to constrain the joint estimations of activity and attenuation approach for PET system using a mixture model prior based on the attenuation map histogram. This novel prior enforces non-negativity and its hyperparameters can be estimated using a mixture decomposition step from the current estimation of the attenuation map. The proposed method can also be helpful on the solving of scaling problem and is capable to assign the predefined regional attenuation coefficients with some degree of confidence to the attenuation map similar to segmentation-based attenuation correction approaches. The performance of the algorithm is studied with numerical and Monte Carlo simulations and a phantom experiment and was compared with MLAA algorithm with and without the smoothing prior. The results demonstrate that the proposed algorithm is capable of producing the cross-talk free activity and attenuation images from emission data. The proposed approach has potential to be a practical and competitive method for joint reconstruction of activity and attenuation maps from emission data on PET/MR and can be integrated on the other methods.

  19. Phillips-Tikhonov regularization with a priori information for neutron emission tomographic reconstruction on Joint European Torus

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bielecki, J.; Scholz, M.; Drozdowicz, K.

    A method of tomographic reconstruction of the neutron emissivity in the poloidal cross section of the Joint European Torus (JET, Culham, UK) tokamak was developed. Due to very limited data set (two projection angles, 19 lines of sight only) provided by the neutron emission profile monitor (KN3 neutron camera), the reconstruction is an ill-posed inverse problem. The aim of this work consists in making a contribution to the development of reliable plasma tomography reconstruction methods that could be routinely used at JET tokamak. The proposed method is based on Phillips-Tikhonov regularization and incorporates a priori knowledge of the shape ofmore » normalized neutron emissivity profile. For the purpose of the optimal selection of the regularization parameters, the shape of normalized neutron emissivity profile is approximated by the shape of normalized electron density profile measured by LIDAR or high resolution Thomson scattering JET diagnostics. In contrast with some previously developed methods of ill-posed plasma tomography reconstruction problem, the developed algorithms do not include any post-processing of the obtained solution and the physical constrains on the solution are imposed during the regularization process. The accuracy of the method is at first evaluated by several tests with synthetic data based on various plasma neutron emissivity models (phantoms). Then, the method is applied to the neutron emissivity reconstruction for JET D plasma discharge #85100. It is demonstrated that this method shows good performance and reliability and it can be routinely used for plasma neutron emissivity reconstruction on JET.« less

  20. Rapid alignment of nanotomography data using joint iterative reconstruction and reprojection

    DOE PAGES

    Gürsoy, Doğa; Hong, Young P.; He, Kuan; ...

    2017-09-18

    As x-ray and electron tomography is pushed further into the nanoscale, the limitations of rotation stages become more apparent, leading to challenges in the alignment of the acquired projection images. Here we present an approach for rapid post-acquisition alignment of these projections to obtain high quality three-dimensional images. Our approach is based on a joint estimation of alignment errors, and the object, using an iterative refinement procedure. With simulated data where we know the alignment error of each projection image, our approach shows a residual alignment error that is a factor of a thousand smaller, and it reaches the samemore » error level in the reconstructed image in less than half the number of iterations. We then show its application to experimental data in x-ray and electron nanotomography.« less

  1. Joint Simultaneous Reconstruction of Regularized Building Superstructures from Low-Density LIDAR Data Using Icp

    NASA Astrophysics Data System (ADS)

    Wichmann, Andreas; Kada, Martin

    2016-06-01

    There are many applications for 3D city models, e.g., in visualizations, analysis, and simulations; each one requiring a certain level of detail to be effective. The overall trend goes towards including various kinds of anthropogenic and natural objects therein with ever increasing geometric and semantic details. A few years back, the featured 3D building models had only coarse roof geometry. But nowadays, they are expected to include detailed roof superstructures like dormers and chimneys. Several methods have been proposed for the automatic reconstruction of 3D building models from airborne based point clouds. However, they are usually unable to reliably recognize and reconstruct small roof superstructures as these objects are often represented by only few point measurements, especially in low-density point clouds. In this paper, we propose a recognition and reconstruction approach that overcomes this problem by identifying and simultaneously reconstructing regularized superstructures of similar shape. For this purpose, candidate areas for superstructures are detected by taking into account virtual sub-surface points that are assumed to lie on the main roof faces below the measured points. The areas with similar superstructures are detected, extracted, grouped together, and registered to one another with the Iterative Closest Point (ICP) algorithm. As an outcome, the joint point density of each detected group is increased, which helps to recognize the shape of the superstructure more reliably and in more detail. Finally, all instances of each group of superstructures are modeled at once and transformed back to their original position. Because superstructures are reconstructed in groups, symmetries, alignments, and regularities can be enforced in a straight-forward way. The validity of the approach is presented on a number of example buildings from the Vaihingen test data set.

  2. Patellofemoral Joint Loads During Running at the Time of Return to Sport in Elite Athletes With ACL Reconstruction.

    PubMed

    Herrington, Lee; Alarifi, Saud; Jones, Richard

    2017-10-01

    Patellofemoral joint pain and degeneration are common in patients who undergo anterior cruciate ligament reconstruction (ACLR). The presence of patellofemoral joint pain significantly affects the patient's ability to continue sport participation and may even affect participation in activities of daily living. The mechanisms behind patellofemoral joint pain and degeneration are unclear, but previous research has identified altered patellofemoral joint loading in individuals with patellofemoral joint pain when running. It is unclear whether this process occurs after ACLR. To assess the patellofemoral joint stresses during running in ACLR knees and compare the findings to the noninjured knee and matched control knees. Controlled laboratory study. Thirty-four elite sports practitioners who had undergone ACLR and 34 age- and sex-matched controls participated in the study. The participants' running gait was assessed via 3D motion capture, and knee loads and forces were calculated by use of inverse dynamics. A significance difference was found in knee extensor moment, knee flexion angles, patellofemoral contact force (about 23% greater), and patellofemoral contact pressure (about 27% greater) between the ACLR and the noninjured limb ( P ≤ .04) and between the ACLR and the control limb ( P ≤ .04); no significant differences were found between the noninjured and control limbs ( P ≥ .44). Significantly greater levels of patellofemoral joint stress and load were found in the ACLR knee compared with the noninjured and control knees. Altered levels of patellofemoral stress in the ACLR knee during running may predispose individuals to patellofemoral joint pain.

  3. Labral reconstruction with iliotibial band autografts and semitendinosus allografts improves hip joint contact area and contact pressure: an in vitro analysis.

    PubMed

    Lee, Simon; Wuerz, Thomas H; Shewman, Elizabeth; McCormick, Frank M; Salata, Michael J; Philippon, Marc J; Nho, Shane J

    2015-01-01

    Labral reconstruction using iliotibial band (ITB) autografts and semitendinosus (Semi-T) allografts has recently been described in cases of labral deficiency. To characterize the joint biomechanics with a labrum-intact, labrum-deficient, and labrum-reconstructed acetabulum in a hip cadaveric model. The hypothesis was that labral resection would decrease contact area, increase contact pressure, and increase peak force, while subsequent labral reconstruction with ITB autografts or Semi-T allografts would restore these values toward the native intact labral state. Controlled laboratory study. Ten fresh-frozen human cadaveric hips were analyzed utilizing thin-film piezoresistive load sensors to measure contact area, contact pressure, and peak force (1) with the native intact labrum, (2) after segmental labral resection, and (3) after graft labral reconstruction with either ITB autografts or Semi-T allografts. Each specimen was examined at 20° of extension and 60° of flexion. Statistical analysis was conducted through 1-way analysis of variance with post hoc Games-Howell tests. For the ITB group, labral resection significantly decreased contact area (at 20°: 73.2%±5.38%, P=.0010; at 60°: 78.5%±6.93%, P=.0063) and increased contact pressure (at 20°: 106.7%±4.15%, P=.0387; at 60°: 103.9%±1.15%, P=.0428). In addition, ITB reconstruction improved contact area (at 20°: 87.2%±12.3%, P=.0130; at 60°: 90.5%±8.81%, P=.0079) and contact pressure (at 20°: 98.5%±5.71%, P=.0476; at 60°: 96.6%±1.13%, P=.0056) from the resected state. Contact pressure at 60° of flexion was significantly lower compared with the native labrum (P=.0420). For the Semi-T group, labral resection significantly decreased contact area (at 20°: 68.1%±12.57%, P=.0002; at 60°: 67.5%±6.70%, P=.0002) and increased contact pressure (at 20°: 105.3%±3.73%, P=.0304; at 60°: 106.8%±4.04%, P=.0231). Semi-T reconstruction improved contact area (at 20°: 87.9%±7.95%, P=.0087; at 60°: 92.9%±13

  4. General phase regularized reconstruction using phase cycling.

    PubMed

    Ong, Frank; Cheng, Joseph Y; Lustig, Michael

    2018-07-01

    To develop a general phase regularized image reconstruction method, with applications to partial Fourier imaging, water-fat imaging and flow imaging. The problem of enforcing phase constraints in reconstruction was studied under a regularized inverse problem framework. A general phase regularized reconstruction algorithm was proposed to enable various joint reconstruction of partial Fourier imaging, water-fat imaging and flow imaging, along with parallel imaging (PI) and compressed sensing (CS). Since phase regularized reconstruction is inherently non-convex and sensitive to phase wraps in the initial solution, a reconstruction technique, named phase cycling, was proposed to render the overall algorithm invariant to phase wraps. The proposed method was applied to retrospectively under-sampled in vivo datasets and compared with state of the art reconstruction methods. Phase cycling reconstructions showed reduction of artifacts compared to reconstructions without phase cycling and achieved similar performances as state of the art results in partial Fourier, water-fat and divergence-free regularized flow reconstruction. Joint reconstruction of partial Fourier + water-fat imaging + PI + CS, and partial Fourier + divergence-free regularized flow imaging + PI + CS were demonstrated. The proposed phase cycling reconstruction provides an alternative way to perform phase regularized reconstruction, without the need to perform phase unwrapping. It is robust to the choice of initial solutions and encourages the joint reconstruction of phase imaging applications. Magn Reson Med 80:112-125, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  5. Prevalence and pattern of glenohumeral injuries among acute high-grade acromioclavicular joint instabilities.

    PubMed

    Pauly, Stephan; Kraus, Natascha; Greiner, Stefan; Scheibel, Markus

    2013-06-01

    With increasing numbers of arthroscopically assisted acromioclavicular (AC) joint stabilization procedures has come an increase in reports of concomitant glenohumeral injuries among AC joint separations. The aim of the present study was to evaluate the prevalence, pattern, and cause of glenohumeral pathologies among a large patient population with acute high-grade AC joint instability. A total of 125 patients (13 women, 112 men) with high-grade AC joint dislocation (6 Rockwood II; 119 Rockwood V) underwent diagnostic glenohumeral arthroscopy before AC joint repair. Pathologic lesions were evaluated for acute or degenerative origin and, if considered relevant, treated all-arthroscopically. Concomitant glenohumeral pathologies were found in 38 of 125 patients (30.4%). Analysis of pathogenesis distinguished different patterns of accompanying injuries: acute intra-articular lesions, related to the recent shoulder trauma, were found in 9 patients (7.2%), degenerative lesions, considered to be unrelated to the recent trauma, were found in 18 (14.4%), and 11 (8.8%) had an unclear traumatic correlation (intermediate group). Within the acute and the degenerative group, affected structures were predominantly partial, articular-sided tears of the anterosuperior rotator cuff, including instabilities of the pulley complex, followed by pathologies of the long head of the biceps and superior labrum anteroposterior lesions. The intermediate group presented mainly with articular-sided partial tears of the subscapularis tendon. This prospective study showed a high prevalence (30%) of concomitant glenohumeral pathologies, of which some indicate additional surgical therapy and could be missed by an isolated open AC repair. Hence, the arthroscopic approach for AC joint stabilization allows for the diagnosis and treatment of associated intra-articular pathologies. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  6. Porous polyurethaneurea (Artelon) joint spacer compared to trapezium resection and ligament reconstruction.

    PubMed

    Blount, Andrew L; Armstrong, Shannon D; Yuan, Frank; Burgess, Scott D

    2013-09-01

    To examine outcomes and complications of the porous polyurethaneurea (Artelon; Small Bone Innovations, Morrisville, PA) spacer compared to traditional surgical treatment of trapeziectomy with ligament reconstruction and tendon interposition (LRTI). A retrospective chart review was undertaken of patients with carpometacarpal (CMC) arthritis who had either placement of an Artelon spacer or LRTI. Patients were brought back to clinic for interview and functional testing. Pain was graded using a visual analog scale. Grip and pinch strength, as well as range of motion at the first CMC joint, were measured. Nine-hole peg, Moberg pickup, and Jebson-Taylor tests were performed. Research and Development 36, Michigan Hand Outcomes, and Quick Disabilities of the Arm, Shoulder, and Hand questionnaires were administered. Thirty-eight patients received Artelon implants into the CMC joint, and 6 were lost to follow-up. Twelve of 32 patients (37%) required revision surgery with removal of implant and salvage arthroplasty. Twenty patients with nonrevised Artelon implants were compared with 10 patients who received 13 LRTI procedures. Patients with Artelon had significantly less pain improvement compared to those receiving the LRTI procedure. In addition, satisfaction was significantly decreased. There was no significant difference in any other functional or quality of life measures. In our practice, use of the Artelon joint spacer resulted in an explantation rate of 37%. Due to these findings, we have abandoned its use for treatment of basilar thumb osteoarthritis. In contrast to previous studies, pain and satisfaction are worse in patients with intact Artelon spacers than those who had received LRTI. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  7. Loss of reduction and complications of coracoclavicular ligament reconstruction with autogenous tendon graft in acute acromioclavicular dislocations.

    PubMed

    Choi, Nam Hong; Lim, Seok Min; Lee, Sang Young; Lim, Tae Kang

    2017-04-01

    This study was conducted to report loss of reduction and complications after single-tunnel coracoclavicular (CC) ligament reconstruction with autogenous semitendinosus tendon graft for acute acromioclavicular (AC) joint dislocations. This retrospective study included patients with acute, unstable AC dislocations (surgery within 6 weeks after trauma). We excluded patients with chronic injury and distal clavicle fractures with CC ligaments disruption. We measured the CC distance on anteroposterior radiographs of both clavicles, preoperatively, immediately postoperatively, and at the final follow-up visit. We evaluated clinical outcomes using the American Shoulder and Elbow Surgeons Shoulder Assessment and the University of California, Los Angeles Shoulder Rating Scale scores and perioperative complications. There were 30 patients (27 men and 3 women) with mean age of 41 years (range, 19-70 years). The mean follow-up period was 31 months (range, 12-186 months). Mean CC distance was 15.5 ± 3.7 mm (84% ± 14% of the contralateral shoulder) preoperatively, 8.9 ± 2.6 mm (9% ± 40%) immediately postoperatively (P < .001), and 10.6 ± 3.3 mm (24% ± 39%) at the final assessment (P < .001), showing an increase of the CC distance during the follow-up. Loss of reduction (defined as >25% increase of CC distance) developed in 14 patients (47%), and complications occurred in 6 patients (20%), including 3 distal clavicle fractures through the tunnel. Final clinical scores were significantly lower in patients with complications (27 vs. 33 of the University of California, Los Angeles assessment [P < .001] and 81 vs. 95 of the American Shoulder and Elbow Surgeons Shoulder assessment [P < .001]). In acute AC joint dislocation, single-tunnel CC ligament reconstruction using autogenous tendon graft resulted in loss of reduction rate of 47% and a complication rate of 20%. The development of complications adversely affected clinical outcomes

  8. JRmGRN: Joint reconstruction of multiple gene regulatory networks with common hub genes using data from multiple tissues or conditions.

    PubMed

    Deng, Wenping; Zhang, Kui; Liu, Sanzhen; Zhao, Patrick; Xu, Shizhong; Wei, Hairong

    2018-04-30

    Joint reconstruction of multiple gene regulatory networks (GRNs) using gene expression data from multiple tissues/conditions is very important for understanding common and tissue/condition-specific regulation. However, there are currently no computational models and methods available for directly constructing such multiple GRNs that not only share some common hub genes but also possess tissue/condition-specific regulatory edges. In this paper, we proposed a new graphic Gaussian model for joint reconstruction of multiple gene regulatory networks (JRmGRN), which highlighted hub genes, using gene expression data from several tissues/conditions. Under the framework of Gaussian graphical model, JRmGRN method constructs the GRNs through maximizing a penalized log likelihood function. We formulated it as a convex optimization problem, and then solved it with an alternating direction method of multipliers (ADMM) algorithm. The performance of JRmGRN was first evaluated with synthetic data and the results showed that JRmGRN outperformed several other methods for reconstruction of GRNs. We also applied our method to real Arabidopsis thaliana RNA-seq data from two light regime conditions in comparison with other methods, and both common hub genes and some conditions-specific hub genes were identified with higher accuracy and precision. JRmGRN is available as a R program from: https://github.com/wenpingd. hairong@mtu.edu. Proof of theorem, derivation of algorithm and supplementary data are available at Bioinformatics online.

  9. Quantum recurrence and fractional dynamic localization in ac-driven perfect state transfer Hamiltonians

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Longhi, Stefano, E-mail: stefano.longhi@fisi.polimi.it

    Quantum recurrence and dynamic localization are investigated in a class of ac-driven tight-binding Hamiltonians, the Krawtchouk quantum chain, which in the undriven case provides a paradigmatic Hamiltonian model that realizes perfect quantum state transfer and mirror inversion. The equivalence between the ac-driven single-particle Krawtchouk Hamiltonian H{sup -hat} (t) and the non-interacting ac-driven bosonic junction Hamiltonian enables to determine in a closed form the quasi energy spectrum of H{sup -hat} (t) and the conditions for exact wave packet reconstruction (dynamic localization). In particular, we show that quantum recurrence, which is predicted by the general quantum recurrence theorem, is exact for themore » Krawtchouk quantum chain in a dense range of the driving amplitude. Exact quantum recurrence provides perfect wave packet reconstruction at a frequency which is fractional than the driving frequency, a phenomenon that can be referred to as fractional dynamic localization.« less

  10. 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

  11. Meta-analysis of antecolic versus retrocolic gastric reconstruction after a pylorus-preserving pancreatoduodenectomy.

    PubMed

    Bell, Richard; Pandanaboyana, Sanjay; Shah, Nehal; Bartlett, Adam; Windsor, John A; Smith, Andrew M

    2015-03-01

    Delayed gastric emptying (DGE) is a common complication after a pylorus-preserving pancreatoduodenectomy (PPPD) and is associated with significant morbidity. This study determines whether DGE is affected by antecolic (AC) or retrocolic (RC) reconstruction after a PPPD. An electronic search was performed of the MEDLINE, EMBASE and PubMed databases to identify all articles related to this topic. Pooled risk ratios (RR) were calculated for categorical outcomes, and mean differences (MD) for secondary continuous outcomes using the fixed-effects and random-effects models for meta-analysis. Nine studies including 878 patients met the inclusion criteria. DGE was lower with an AC reconstruction RR 0.31 [0.12, 0.78] Z = 2.47 (P = 0.010). Length of stay (LOS) MD -4 days [-7.63, -1.14] Z = 2.65 (P = 0.008) and days to commence a solid diet MD -5 days [-6.63, -3.15] Z = 5.50 (P ≤ 0.000) were also significantly in favour of the AC group. There was no difference in the incidence of pancreatic fistula, intra-abdominal collection/bile leak or mortality between the two groups. AC reconstruction after PPPD is associated with a lower incidence of DGE. Time to oral intake was significantly shorter with AC reconstruction, with a reduced hospital stay. © 2014 International Hepato-Pancreato-Biliary Association.

  12. 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

  13. Isokinetic Identification of Knee Joint Torques before and after Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Czaplicki, Adam; Jarocka, Marta; Walawski, Jacek

    2015-01-01

    The aim of this study was to evaluate the serial change of isokinetic muscle strength of the knees before and after anterior cruciate ligament reconstruction (ACLR) in physically active males and to estimate the time of return to full physical fitness. Extension and flexion torques were measured for the injured and healthy limbs at two angular velocities approximately 1.5 months before the surgery and 3, 6, and 12 months after ACLR. Significant differences (p ≤ 0.05) in peak knee extension and flexion torques, hamstring/quadriceps (H/Q) strength ratios, uninvolved/involved limb peak torque ratios, and the normalized work of these muscles between the four stages of rehabilitation were identified. Significant differences between extension peak torques for the injured and healthy limbs were also detected at all stages. The obtained results showed that 12 months of rehabilitation were insufficient for the involved knee joint to recover its strength to the level of strength of the uninvolved knee joint. The results helped to evaluate the progress of the rehabilitation and to implement necessary modifications optimizing the rehabilitation training program. The results of the study may also be used as referential data for physically active males of similar age. PMID:26646385

  14. Midshaft clavicle fractures with associated ipsilateral acromioclavicular joint dislocations: Incidence and risk factors.

    PubMed

    Ottomeyer, Christina; Taylor, Benjamin C; Isaacson, Mark; Martinez, Lara; Ebaugh, Pierce; French, Bruce G

    2017-02-01

    Simultaneous ipsilateral clavicle and acromioclavicular (AC) joint injury have been infrequently reported in the literature at this time. The purpose of this study was to assess incidence as well as assess risk factors for this dual injury pattern. We performed a retrospective review of a prospectively collected database (Level III evidence), evaluating 383 adult patients without previous shoulder girdle injury or trauma with a minimum 1-year follow-up who sustained a displaced diaphyseal clavicle fracture. All patients in the study underwent either nonoperative management or surgical reduction and stabilization of a diaphyseal clavicle fracture with a plate and screw construct. Study subjects were followed with serial radiographs. Clavicle and shoulder radiographs, as well as chest radiographs and contralateral films in questionable cases, were used to assess for acromioclavicular joint injury in both operative and nonoperative groups. Additional data was collected on concurrent injuries, patient demographics, fracture characteristics, fixation techniques, surgical/post-operative data, and operative or nonoperative treatment. We found that 13/183 (7.1%) of patients undergoing fixation of a diaphyseal clavicle fracture had an ipsilateral AC joint injury, while 13/200 (6.5%) of patients undergoing conservative management had an ipsilateral AC joint injury. Critical analysis of the data revealed that presence of ipsilateral scapular body fractures, and a likely incidental association with superior plating fixation, were associated with an increased rate of this injury pattern. Ipsilateral clavicle fracture and AC joint injury is much more common than traditionally believed, with an incidence of 6.8% overall. It is unknown how the presence of an associated AC injury influences outcome, as AC injury was not universally symptomatic. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Human arm joints reconstruction algorithm in rehabilitation therapies assisted by end-effector robotic devices.

    PubMed

    Bertomeu-Motos, Arturo; Blanco, Andrea; Badesa, Francisco J; Barios, Juan A; Zollo, Loredana; Garcia-Aracil, Nicolas

    2018-02-20

    End-effector robots are commonly used in robot-assisted neuro-rehabilitation therapies for upper limbs where the patient's hand can be easily attached to a splint. Nevertheless, they are not able to estimate and control the kinematic configuration of the upper limb during the therapy. However, the Range of Motion (ROM) together with the clinical assessment scales offers a comprehensive assessment to the therapist. Our aim is to present a robust and stable kinematic reconstruction algorithm to accurately measure the upper limb joints using only an accelerometer placed onto the upper arm. The proposed algorithm is based on the inverse of the augmented Jaciobian as the algorithm (Papaleo, et al., Med Biol Eng Comput 53(9):815-28, 2015). However, the estimation of the elbow joint location is performed through the computation of the rotation measured by the accelerometer during the arm movement, making the algorithm more robust against shoulder movements. Furthermore, we present a method to compute the initial configuration of the upper limb necessary to start the integration method, a protocol to manually measure the upper arm and forearm lengths, and a shoulder position estimation. An optoelectronic system was used to test the accuracy of the proposed algorithm whilst healthy subjects were performing upper limb movements holding the end effector of the seven Degrees of Freedom (DoF) robot. In addition, the previous and the proposed algorithms were studied during a neuro-rehabilitation therapy assisted by the 'PUPArm' planar robot with three post-stroke patients. The proposed algorithm reports a Root Mean Square Error (RMSE) of 2.13cm in the elbow joint location and 1.89cm in the wrist joint location with high correlation. These errors lead to a RMSE about 3.5 degrees (mean of the seven joints) with high correlation in all the joints with respect to the real upper limb acquired through the optoelectronic system. Then, the estimation of the upper limb joints through

  16. Palpation Versus Ultrasound-Guided Acromioclavicular Joint Intra-articular Corticosteroid Injections: A Retrospective Comparative Clinical Study.

    PubMed

    Park, Ki Deok; Kim, Tai Kon; Lee, Jihae; Lee, Woo Yong; Ahn, Jae Ki; Park, Yongbum

    2015-01-01

    Primary osteoarthritis (OA) is the most common cause of pain arising from the acromioclavicular (AC) joint. The true incidence is unknown because of differences in the criteria used to define arthritis in various studies. The proper diagnosis of AC joint OA requires a thorough physical examination, radiographic findings, and a diagnostic local anesthetic injection. The goal of this study was to assess the effects and safety of ultrasound (US) versus palpation-guided acromioclavicular (AC) joint intra-articular (IA) corticosteroid injection for patients with osteoarthritis (OA) of the AC joint. Retrospective, compared clinical study. University hospital outpatient pain clinic. We retrospectively reviewed the charts of patients with AC joint degenerative OA who had undergone US or palpation-guided AC joint IA corticosteroid injection between January 2012 and December 2013 at our outpatient clinic. One hundred consecutive patients identified from chart review met inclusion criteria. Patients (N = 50) in US guide AC joint IA steroid injection group were administered a mixture of 0.5% lidocaine (1 mL) with triamcinolone (20 mg/mL; 0.5 mL) and radiographic contrast material (0.5 mL) and patients (N = 50) in palpation-guided AC joint IA steroid injection group were administered a mixture of 0.5% lidocaine (1 mL) with triamcinolone (20 mg/mL; 0.5 mL) and 0.5 mL of radiographic contrast material. Results were measured using the Shoulder Pain and Disability Index (SPADI), Verbal Numeric pain Scale (VNS) at rest (VNSar), under local pressure (VNSlp) ,and the arm adduction test (VNSaat) at the joint space area before injections and at one, 3, and 6 months after the injections. Successful treatment occurred when patients obtained significant pain relief (as measured by > 50% improvement in the VNS score and 20 point improvement in the SPADI) at one, 3, and 6 months after the injections. Univariable analysis was performed to evaluate the relationship between possible outcome

  17. Temporo mandibular joint ankylosis.

    PubMed

    Vasconcelos, Belmiro Cavalcanti do Egito; Porto, Gabriela Granja; Bessa-Nogueira, Ricardo Viana

    2008-01-01

    Ankylosis may be defined as joint surfaces fusion. The treatment of temporomandibular joint ankylosis poses a significant challenge because of the high recurrence rate. The aim of this study is to report six cases treated by joint reconstruction, evaluate the results of these surgeries and review the literature. The sample in this retrospective study was obtained from the records of the university hospital, patients who had to undergo ankylosis treatment by alloplastic or autogenous graft between March 2001 and October 2005. Pre - and post-operative assessment included a throughout history and physical examination to determine the cause of ankylosis, the Maximum mouth opening (MMO), etiology and type of ankylosis, recurrence rate and presence of facial nerve paralysis. The mean MMO in the pre-operative period was 9.6 mm (0 mm to 17 mm) and in the post-operative period it was of 31.33 mm (14 mm to 41 mm), there was no facial nerve paralysis and there was recurrence in just one case. The joint reconstruction with alloplastic or autogenous grafts for the ankylosis treatment proved to be efficient in relation to the post-operative MMO, recurrence and joint function.

  18. Sports activity after anatomic acromioclavicular joint stabilisation with flip-button technique.

    PubMed

    Porschke, Felix; Schnetzke, Marc; Aytac, Sara; Studier-Fischer, Stefan; Gruetzner, Paul Alfred; Guehring, Thorsten

    2017-07-01

    Sports activity after surgical AC joint stabilisation has not been comprehensively evaluated to date. The aim of this study was to determine rate, level and time to return to sports after AC joint stabilisation and to identify the influence of overhead sports on post-operative sports activity. In this retrospective case series, a total of 68 patients with a high-grade AC joint dislocation (Rockwood type V) were stabilised using a single TightRope technique. Fifty-five patients (80.9 %) with median age of 42.0 (range, 18-65) years completed questionnaires regarding sports activity before and after surgery. Clinical outcome and complications were also evaluated. Forty-three patients participated in sports regularly before injury. Their sports activity was rated according to Allain, and non-overhead and overhead sports were differentiated. At median follow-up of 24 (18-45) months, 41 of 43 patients (95.3 %) had returned to sports. 63 % returned to the same sports activity as before injury. 16.3 % needed to adapt the type of sports to reduce demanding activities. 11.6 % reduced the frequency and 32.5 % the intensity of sports. The median time to return to sports was 9.5 (3-18) months. Overhead athletes (Allain Type III and IV) had to reduce their sports activity significantly more often (11.8 vs. 53.8 %; p = 0.011) and needed more time to return to sports (9.5 vs. 4.5 months; p = 0.009). After stabilisation of AC joint dislocation, the majority of patients returned to sports after a substantial period of time. Overhead athletes, in particular, required more time and had to considerably reduce their sports activity. The findings impact therapeutic decision-making after AC joint injury and help with the prognosis and assessment of rehabilitation progress. IV.

  19. Numerically correcting the joint misplacement of the sub-holograms in spatial synthetic aperture digital Fresnel holography.

    PubMed

    Jiang, Hongzhen; Zhao, Jianlin; Di, Jianglei; Qin, Chuan

    2009-10-12

    We propose an effective reconstruction method for correcting the joint misplacement of the sub-holograms caused by the displacement error of CCD in spatial synthetic aperture digital Fresnel holography. For every two adjacent sub-holograms along the motion path of CCD, we reconstruct the corresponding holographic images under different joint distances between the sub-holograms and then find out the accurate joint distance by evaluating the quality of the corresponding synthetic reconstructed images. Then the accurate relative position relationships of the sub-holograms can be confirmed according to all of the identified joint distances, with which the accurate synthetic reconstructed image can be obtained by superposing the reconstruction results of the sub-holograms. The numerical reconstruction results are in agreement with the theoretical analysis. Compared with the traditional reconstruction method, this method could be used to not only correct the joint misplacement of the sub-holograms without the limitation of the actually overlapping circumstances of the adjacent sub-holograms, but also make the joint precision of the sub-holograms reach sub-pixel accuracy.

  20. Inter- and intraobserver reliability of the Rockwood classification in acute acromioclavicular joint dislocations.

    PubMed

    Schneider, M M; Balke, M; Koenen, P; Fröhlich, M; Wafaisade, A; Bouillon, B; Banerjee, M

    2016-07-01

    The reliability of the Rockwood classification, the gold standard for acute acromioclavicular (AC) joint separations, has not yet been tested. The purpose of this study was to investigate the reliability of visual and measured AC joint lesion grades according to the Rockwood classification. Four investigators (two shoulder specialists and two second-year residents) examined radiographs (bilateral panoramic stress and axial views) in 58 patients and graded the injury according to the Rockwood classification using the following sequence: (1) visual classification of the AC joint lesion, (2) digital measurement of the coracoclavicular distance (CCD) and the horizontal dislocation (HD) with Osirix Dicom Viewer (Pixmeo, Switzerland), (3) classification of the AC joint lesion according to the measurements and (4) repetition of (1) and (2) after repeated anonymization by an independent physician. Visual and measured Rockwood grades as well as the CCD and HD of every patient were documented, and a CC index was calculated (CCD injured/CCD healthy). All records were then used to evaluate intra- and interobserver reliability. The disagreement between visual and measured diagnosis ranged from 6.9 to 27.6 %. Interobserver reliability for visual diagnosis was good (0.72-0.74) and excellent (0.85-0.93) for measured Rockwood grades. Intraobserver reliability was good to excellent (0.67-0.93) for visual diagnosis and excellent for measured diagnosis (0.90-0.97). The correlations between measurements of the axial view varied from 0.68 to 0.98 (good to excellent) for interobserver reliability and from 0.90 to 0.97 (excellent) for intraobserver reliability. Bilateral panoramic stress and axial radiographs are reliable examinations for grading AC joint injuries according to Rockwood's classification. Clinicians of all experience levels can precisely classify AC joint lesions according to the Rockwood classification. We recommend to grade acute ACG lesions by performing a digital

  1. Quadriceps Strength Asymmetry Following ACL Reconstruction Alters Knee Joint Biomechanics and Functional Performance at Time of Return to Activity

    PubMed Central

    Palmieri-Smith, RM; Lepley, LK

    2016-01-01

    Background Quadriceps strength deficits are observed clinically following anterior cruciate injury and reconstruction and are often not overcome despite rehabilitation. Given that quadriceps strength may be important for achieving symmetrical joint biomechanics and promoting long-term joint health, determining the magnitude of strength deficits that lead to altered mechanics is critical. Purpose To determine if the magnitude of quadriceps strength asymmetry alters knee and hip biomechanical symmetry, as well as functional performance and self-reported function. Study Design Cross-Sectional study. Methods Seventy-three patients were tested at the time they were cleared for return to activity following ACL reconstruction. Quadriceps strength and activation, scores on the International Knee Documentation Committee form, the hop for distance test, and sagittal plane lower extremity biomechanics were recorded while patients completed a single-legged hop. Results Patients with high and moderate quadriceps strength symmetry had larger central activation ratios as well as greater limb symmetry indices on the hop for distance compared to patients with low quadriceps strength symmetry (P<0.05). Similarly, knee flexion angle and external moment symmetry was higher in the patients with high and moderate quadriceps symmetry compared to those with low symmetry (P<0.05). Quadriceps strength was found to be associated with sagittal plane knee angle and moment symmetry (P<0.05). Conclusion Patients with low quadriceps strength displayed greater movement asymmetries at the knee in the sagittal plane. Quadriceps strength was related to movement asymmetries and functional performance. Rehabilitation following ACL reconstruction needs to focus on maximizing quadriceps strength, which likely will lead to more symmetrical knee biomechanics. PMID:25883169

  2. Parallel Reconstruction Using Null Operations (PRUNO)

    PubMed Central

    Zhang, Jian; Liu, Chunlei; Moseley, Michael E.

    2011-01-01

    A novel iterative k-space data-driven technique, namely Parallel Reconstruction Using Null Operations (PRUNO), is presented for parallel imaging reconstruction. In PRUNO, both data calibration and image reconstruction are formulated into linear algebra problems based on a generalized system model. An optimal data calibration strategy is demonstrated by using Singular Value Decomposition (SVD). And an iterative conjugate- gradient approach is proposed to efficiently solve missing k-space samples during reconstruction. With its generalized formulation and precise mathematical model, PRUNO reconstruction yields good accuracy, flexibility, stability. Both computer simulation and in vivo studies have shown that PRUNO produces much better reconstruction quality than autocalibrating partially parallel acquisition (GRAPPA), especially under high accelerating rates. With the aid of PRUO reconstruction, ultra high accelerating parallel imaging can be performed with decent image quality. For example, we have done successful PRUNO reconstruction at a reduction factor of 6 (effective factor of 4.44) with 8 coils and only a few autocalibration signal (ACS) lines. PMID:21604290

  3. Anisotropic modeling and joint-MAP stitching for improved ultrasound model-based iterative reconstruction of large and thick specimens

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Almansouri, Hani; Venkatakrishnan, Singanallur V.; Clayton, Dwight A.

    One-sided non-destructive evaluation (NDE) is widely used to inspect materials, such as concrete structures in nuclear power plants (NPP). A widely used method for one-sided NDE is the synthetic aperture focusing technique (SAFT). The SAFT algorithm produces reasonable results when inspecting simple structures. However, for complex structures, such as heavily reinforced thick concrete structures, SAFT results in artifacts and hence there is a need for a more sophisticated inversion technique. Model-based iterative reconstruction (MBIR) algorithms, which are typically equivalent to regularized inversion techniques, offer a powerful framework to incorporate complex models for the physics, detector miscalibrations and the materials beingmore » imaged to obtain high quality reconstructions. Previously, we have proposed an ultrasonic MBIR method that signifcantly improves reconstruction quality compared to SAFT. However, the method made some simplifying assumptions on the propagation model and did not disucss ways to handle data that is obtained by raster scanning a system over a surface to inspect large regions. In this paper, we propose a novel MBIR algorithm that incorporates an anisotropic forward model and allows for the joint processing of data obtained from a system that raster scans a large surface. We demonstrate that the new MBIR method can produce dramatic improvements in reconstruction quality compared to SAFT and suppresses articfacts compared to the perviously presented MBIR approach.« less

  4. Anisotropic modeling and joint-MAP stitching for improved ultrasound model-based iterative reconstruction of large and thick specimens

    NASA Astrophysics Data System (ADS)

    Almansouri, Hani; Venkatakrishnan, Singanallur; Clayton, Dwight; Polsky, Yarom; Bouman, Charles; Santos-Villalobos, Hector

    2018-04-01

    One-sided non-destructive evaluation (NDE) is widely used to inspect materials, such as concrete structures in nuclear power plants (NPP). A widely used method for one-sided NDE is the synthetic aperture focusing technique (SAFT). The SAFT algorithm produces reasonable results when inspecting simple structures. However, for complex structures, such as heavily reinforced thick concrete structures, SAFT results in artifacts and hence there is a need for a more sophisticated inversion technique. Model-based iterative reconstruction (MBIR) algorithms, which are typically equivalent to regularized inversion techniques, offer a powerful framework to incorporate complex models for the physics, detector miscalibrations and the materials being imaged to obtain high quality reconstructions. Previously, we have proposed an ultrasonic MBIR method that signifcantly improves reconstruction quality compared to SAFT. However, the method made some simplifying assumptions on the propagation model and did not disucss ways to handle data that is obtained by raster scanning a system over a surface to inspect large regions. In this paper, we propose a novel MBIR algorithm that incorporates an anisotropic forward model and allows for the joint processing of data obtained from a system that raster scans a large surface. We demonstrate that the new MBIR method can produce dramatic improvements in reconstruction quality compared to SAFT and suppresses articfacts compared to the perviously presented MBIR approach.

  5. Biologically inspired EM image alignment and neural reconstruction.

    PubMed

    Knowles-Barley, Seymour; Butcher, Nancy J; Meinertzhagen, Ian A; Armstrong, J Douglas

    2011-08-15

    Three-dimensional reconstruction of consecutive serial-section transmission electron microscopy (ssTEM) images of neural tissue currently requires many hours of manual tracing and annotation. Several computational techniques have already been applied to ssTEM images to facilitate 3D reconstruction and ease this burden. Here, we present an alternative computational approach for ssTEM image analysis. We have used biologically inspired receptive fields as a basis for a ridge detection algorithm to identify cell membranes, synaptic contacts and mitochondria. Detected line segments are used to improve alignment between consecutive images and we have joined small segments of membrane into cell surfaces using a dynamic programming algorithm similar to the Needleman-Wunsch and Smith-Waterman DNA sequence alignment procedures. A shortest path-based approach has been used to close edges and achieve image segmentation. Partial reconstructions were automatically generated and used as a basis for semi-automatic reconstruction of neural tissue. The accuracy of partial reconstructions was evaluated and 96% of membrane could be identified at the cost of 13% false positive detections. An open-source reference implementation is available in the Supplementary information. seymour.kb@ed.ac.uk; douglas.armstrong@ed.ac.uk Supplementary data are available at Bioinformatics online.

  6. Influence of reconstruction algorithms on image quality in SPECT myocardial perfusion imaging.

    PubMed

    Davidsson, Anette; Olsson, Eva; Engvall, Jan; Gustafsson, Agnetha

    2017-11-01

    We investigated if image- and diagnostic quality in SPECT MPI could be maintained despite a reduced acquisition time adding Depth Dependent Resolution Recovery (DDRR) for image reconstruction. Images were compared with filtered back projection (FBP) and iterative reconstruction using Ordered Subsets Expectation Maximization with (IRAC) and without (IRNC) attenuation correction (AC). Stress- and rest imaging for 15 min was performed on 21 subjects with a dual head gamma camera (Infinia Hawkeye; GE Healthcare), ECG-gating with 8 frames/cardiac cycle and a low-dose CT-scan. A 9 min acquisition was generated using five instead of eight gated frames and was reconstructed with DDRR, with (IRACRR) and without AC (IRNCRR) as well as with FBP. Three experienced nuclear medicine specialists visually assessed anonymized images according to eight criteria on a four point scale, three related to image quality and five to diagnostic confidence. Statistical analysis was performed using Visual Grading Regression (VGR). Observer confidence in statements on image quality was highest for the images that were reconstructed using DDRR (P<0·01 compared to FBP). Iterative reconstruction without DDRR was not superior to FBP. Interobserver variability was significant for statements on image quality (P<0·05) but lower in the diagnostic statements on ischemia and scar. The confidence in assessing ischemia and scar was not different between the reconstruction techniques (P = n.s.). SPECT MPI collected in 9 min, reconstructed with DDRR and AC, produced better image quality than the standard procedure. The observers expressed the highest diagnostic confidence in the DDRR reconstruction. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  7. Biomechanical analysis of acromioclavicular joint dislocation repair using coracoclavicular suspension devices in two different configurations.

    PubMed

    Abat, Ferran; Sarasquete, Juan; Natera, Luis Gerardo; Calvo, Ángel; Pérez-España, Manuel; Zurita, Néstor; Ferrer, Jesús; del Real, Juan Carlos; Paz-Jimenez, Eva; Forriol, Francisco

    2015-09-01

    The best treatment option for some acromioclavicular (AC) joint dislocations is controversial. For this reason, the aim of this study was to evaluate the vertical biomechanical behavior of two techniques for the anatomic repair of coracoclavicular (CC) ligaments after an AC injury. Eighteen human cadaveric shoulders in which repair using a coracoclavicular suspension device was initiated after injury to the acromioclavicular joint were included in the study. Three groups were formed; group I (n = 6): control; group II (n = 6): repair with a double tunnel in the clavicle and in the coracoid (with two CC suspension devices); group III (n = 6): repair in a "V" configuration with two tunnels in the clavicle and one in the coracoid (with one CC suspension device). The biomechanical study was performed with a universal testing machine (Electro Puls 3000, Instron, Boulder, MA, USA), with the clamping jaws set in a vertical position. The force required for acromioclavicular reconstruction system failure was analyzed for each cadaveric piece. Group I reached a maximum force to failure of 635.59 N (mean 444.0 N). The corresponding force was 939.37 N (mean 495.6 N) for group II and 533.11 N (mean 343.9 N) for group III. A comparison of the three groups did not find any significant difference despite the loss of resistance presented by group III. Anatomic repair of coracoclavicular ligaments with a double system (double tunnel in the clavicle and in the coracoid) permits vertical translation that is more like that of the acromioclavicular joint. Acromioclavicular repair in a "V" configuration does not seem to be biomechanically sufficient.

  8. 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

  9. MR-Consistent Simultaneous Reconstruction of Attenuation and Activity for Non-TOF PET/MR

    NASA Astrophysics Data System (ADS)

    Heußer, Thorsten; Rank, Christopher M.; Freitag, Martin T.; Dimitrakopoulou-Strauss, Antonia; Schlemmer, Heinz-Peter; Beyer, Thomas; Kachelrieß, Marc

    2016-10-01

    Attenuation correction (AC) is required for accurate quantification of the reconstructed activity distribution in positron emission tomography (PET). For simultaneous PET/magnetic resonance (MR), however, AC is challenging, since the MR images do not provide direct information on the attenuating properties of the underlying tissue. Standard MR-based AC does not account for the presence of bone and thus leads to an underestimation of the activity distribution. To improve quantification for non-time-of-flight PET/MR, we propose an algorithm which simultaneously reconstructs activity and attenuation distribution from the PET emission data using available MR images as anatomical prior information. The MR information is used to derive voxel-dependent expectations on the attenuation coefficients. The expectations are modeled using Gaussian-like probability functions. An iterative reconstruction scheme incorporating the prior information on the attenuation coefficients is used to update attenuation and activity distribution in an alternating manner. We tested and evaluated the proposed algorithm for simulated 3D PET data of the head and the pelvis region. Activity deviations were below 5% in soft tissue and lesions compared to the ground truth whereas standard MR-based AC resulted in activity underestimation values of up to 12%.

  10. Joint correction of respiratory motion artifact and partial volume effect in lung/thoracic PET/CT imaging.

    PubMed

    Chang, Guoping; Chang, Tingting; Pan, Tinsu; Clark, John W; Mawlawi, Osama R

    2010-12-01

    Respiratory motion artifacts and partial volume effects (PVEs) are two degrading factors that affect the accuracy of image quantification in PET/CT imaging. In this article, the authors propose a joint motion and PVE correction approach (JMPC) to improve PET quantification by simultaneously correcting for respiratory motion artifacts and PVE in patients with lung/thoracic cancer. The objective of this article is to describe this approach and evaluate its performance using phantom and patient studies. The proposed joint correction approach incorporates a model of motion blurring, PVE, and object size/shape. A motion blurring kernel (MBK) is then estimated from the deconvolution of the joint model, while the activity concentration (AC) of the tumor is estimated from the normalization of the derived MBK. To evaluate the performance of this approach, two phantom studies and eight patient studies were performed. In the phantom studies, two motion waveforms-a linear sinusoidal and a circular motion-were used to control the motion of a sphere, while in the patient studies, all participants were instructed to breathe regularly. For the phantom studies, the resultant MBK was compared to the true MBK by measuring a correlation coefficient between the two kernels. The measured sphere AC derived from the proposed method was compared to the true AC as well as the ACs in images exhibiting PVE only and images exhibiting both PVE and motion blurring. For the patient studies, the resultant MBK was compared to the motion extent derived from a 4D-CT study, while the measured tumor AC was compared to the AC in images exhibiting both PVE and motion blurring. For the phantom studies, the estimated MBK approximated the true MBK with an average correlation coefficient of 0.91. The tumor ACs following the joint correction technique were similar to the true AC with an average difference of 2%. Furthermore, the tumor ACs on the PVE only images and images with both motion blur and PVE effects

  11. Luminescence dating of the lacustrine record of Vršac (Carpathian Basin, Serbia) - implications for a palaeoenvironmetal reconstruction

    NASA Astrophysics Data System (ADS)

    Klasen, N.; Zeeden, C.; Markovic, S.; Fischer, P.; Lehmkuhl, F.; Schulte, P.; Bösken, J.; Hambach, U.; Vött, A.

    2017-12-01

    The Carpathian Basin is one of the key areas to investigate the influence of the continental, Mediterranean and Atlantic climate interaction over Europe. The available Upper Pleistocene and Holocene geoarchives in the region are mainly loess-paleosol records. Long lacustrine records are sparse and do not always span the whole last glacial cycle. In the area around Vršac, we drilled a 10 m core to contribute to the palaeoenvironmental reconstruction of the Carpathian Basin. Electrical Resistivity Tomography (ERT) was used to find the best-suited drilling location. We applied luminescence and radiocarbon dating, because a robust chronology is important for the interpretation of the sedimentary record. Pulsed OSL measurements were carried out to identify the best sampling positions. We expect runoff from the catchment being the main source of the lacustrine sediments, because coarse fluvial input is absent. Knowledge about the depositional conditions is important in luminescence dating to evaluate partial bleaching prior to deposition, which may cause age overestimation. Therefore, we compared infrared stimulated luminescence (IRSL) signals with post infrared infrared stimulated luminescence (pIRIR) signals, which bleach at different rates. Estimation of a representative water content has major influence on the age estimate, but remains challenging in luminescence dating. We measured the present day water content as well as the saturation water content, to account for variations over time. Luminescence and radiocarbon ages differ greatly from each other. According to the laboratory experiments, luminescence dating was reliable and we conclude that radiocarbon ages were underestimated because of an intrusion of younger organic material. The initial results demonstrated the potential of the drill core. Integrating more proxy data will be useful to enhance the importance of the geoarchive at Vršac for a better understanding of the last glacial cycle in the Carpathian

  12. Accuracy of in vivo palpation-guided acromioclavicular joint injection assessed with contrast material and fluoroscopic evaluations.

    PubMed

    Scillia, Anthony; Issa, Kimona; McInerney, Vincent K; Milman, Edward; Baltazar, Romulo; Dasti, Umer; Festa, Anthony

    2015-08-01

    The purpose of this study was to evaluate the accuracy of in vivo acromioclavicular (AC) joint injections without fluoroscopic guidance and assess whether patient demographics affected the accuracy of injections. A consecutive cohort of patients who presented with painful acromioclavicular joints was prospectively evaluated. All patients had clinical and radiographic evidence of AC arthritis, had failed conservative measures, and thus had received intraarticular corticosteroid injections. All injections were performed by experienced fellowship-trained musculoskeletal radiologists and by blinded digital palpation technique. Accuracy of injections was assessed with biplanar fluoroscopic views. Forty-one AC injections in 22 males and 16 females with a mean age of 51 years (range 18 to 78) were identified. Twenty-three injections were in the right shoulder and 18 in the left. Only 15 injections were confirmed to be in the intraarticular AC joint, yielding an accuracy of 36.5%. There were no significant differences in the mean age (54 vs. 52 years; p = 0.58), male-to-female ratio (p = 0.73), and side of the injection between the accurate and inaccurate injections, respectively. Based on the findings of the present study, the authors encourage the use of image guidance for corticosteroid treatment of the AC joint. Level IV Therapeutic Case Series.

  13. 3D reconstruction of bony elements of the knee joint and finite element analysis of total knee prosthesis obtained from the reconstructed model.

    PubMed

    Djoudi, Farid

    2013-01-01

    Two separate themes are presented in this paper. The first theme is to present a graphical modeling approach of human anatomical structures namely, the femur and the tibia. The second theme involves making a finite element analysis of stresses, displacements and deformations in prosthetic implants (the femoral implant and the polyethylene insert). The graphical modeling approach comes in two parts. The first is the segmentation of MRI scanned images, retrieved in DICOM format for edge detection. In the second part, 3D-CAD models are generated from the results of the segmentation stage. The finite element analysis is done by first extracting the prosthetic implants from the reconstructed 3D-CAD model, then do a finite element analysis of these implants under objectively determined conditions such as; forces, allowed displacements, the materials composing implant, and the coefficient of friction. The objective of this work is to implement an interface for exchanging data between 2D MRI images obtained from a medical diagnosis of a patient and the 3D-CAD model used in various applications, such as; the extraction of the implants, stress analysis at the knee joint and can serve as an aid to surgery, also predict the behavior of the prosthetic implants vis-a-vis the forces acting on the knee joints.

  14. Relationship between quadriceps strength and patellofemoral joint chondral lesions after anterior cruciate ligament reconstruction.

    PubMed

    Wang, Hai-Jun; Ao, Ying-Fang; Jiang, Dong; Gong, Xi; Wang, Yong-Jian; Wang, Jian; Yu, Jia-Kuo

    2015-09-01

    The incidence of the patellofemoral joint chondral lesions after anterior cruciate ligament reconstruction (ACLR) is disturbingly high. Few studies have assessed the factors affecting patellofemoral joint chondral lesions postoperatively. The recovery of quadriceps strength after ACLR could be associated with patellofemoral joint cartilage damage. Cohort study; Level of evidence, 3. A total of 88 patients who underwent arthroscopic anatomic double-bundle ACLR with hamstring autografts received second-look arthroscopy at the time of metal staple removal at an average of 24.1 months (range, 12-51 months) postoperatively. All patients underwent standardized isokinetic strength testing for bilateral quadriceps and hamstrings 1 to 2 days before second-look arthroscopy. The patients were divided into 2 groups: Patients in group 1 had a ≥20% deficit on the peak torque measures for quadriceps compared with that of the contralateral knee, whereas those in group 2 had a <20% deficit on peak torque. Cartilage status at the patellofemoral joint and tibiofemoral joint were evaluated by second-look arthroscopy and the Outerbridge classification. Other assessments included the International Knee Documentation Committee (IKDC) score, Tegner and Lysholm scores, side-to-side difference on KT-2000 arthrometer, and range of motion. There were 42 patients included in group 1 and 46 patients in group 2. The mean postoperative quadriceps peak torque of the involved knee compared with the contralateral knee was 70% (range, 57%-80%) in group 1 and 95% (range, 81%-116%) in group 2. For all patients, a significant worsening was seen in the patellar and trochlear cartilage (P = .030 and <.001, respectively) but not at the medial or lateral tibiofemoral joint after ACLR. A significant worsening in the status of both patellar and trochlear cartilage was seen after ACLR in group 1 (P = .013 and =.011, respectively) and of trochlear cartilage in group 2 (P = .006). Significantly fewer severe

  15. MRI reconstruction with joint global regularization and transform learning.

    PubMed

    Tanc, A Korhan; Eksioglu, Ender M

    2016-10-01

    Sparsity based regularization has been a popular approach to remedy the measurement scarcity in image reconstruction. Recently, sparsifying transforms learned from image patches have been utilized as an effective regularizer for the Magnetic Resonance Imaging (MRI) reconstruction. Here, we infuse additional global regularization terms to the patch-based transform learning. We develop an algorithm to solve the resulting novel cost function, which includes both patchwise and global regularization terms. Extensive simulation results indicate that the introduced mixed approach has improved MRI reconstruction performance, when compared to the algorithms which use either of the patchwise transform learning or global regularization terms alone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. The research of laryngeal joints to reconstruction and modeling.

    PubMed

    Zhang, Yi; Shi, Tingchun

    2014-01-01

    Larynx has a complex structure with joints and multiple functions. In order to study the artificial larynx and artificial auricle scaffold, a three-dimensional digital model of laryngeal joint is established in this paper using MIMICS with its biomechanical properties analyzed and calculated by using the finite element method. This model is based on the CT scanned images of 281 layers with an interlamellar spacing of 1.25 mm. The obtained data are denoised, segmented and smoothed before being loaded into MIMICS. By further optimizations, an accurate and complete 3D model can be obtained. Subsequently, a 3D FEM of the normal larynx joint is performed which allows observations from any dimensions and angles. Compared with natural laryngeal joint, this model has good geometric similarity and mechanically similar throat voicing functions.

  17. [Inferior hemiarthroplasty of the temporo-mandibular joint with articulated condylar prosthesis type Stryker].

    PubMed

    Bucur, A; Dincă, O; Totan, C; Ghită, V

    2007-01-01

    The optimal reconstruction of the mandible and of the temporo-mandibular joint after mandibular hemi-resection with disarticulation is still controversial in literature. This paperwork presents our experience on four cases in the reconstruction of the mandible together with the inferior arthroplasty of the temporo-mandibular joint, after the resection of extended benign tumors of the mandible, based on fibular free vascularized grafts having attached a Stryker titanium condylar prosthesis reconstructing the inferior segment of the temporo-mandibular joint. Our results for the this technique were excellent, with a functional rehabilitation very close to normal. After reviewing the various techniques and their arguments in literature, with accent on the TMJ reconstruction, we consider this method to be optimal for the reconstruction of mandibular defects in patients with neoplastic conditions.

  18. Dorsoradial capsulodesis for trapeziometacarpal joint instability.

    PubMed

    Rayan, Ghazi; Do, Viet

    2013-02-01

    We describe an alternative method for treating chronic trapeziometacarpal (TM) joint instability after acute injury or chronic repetitive use of the thumb by performing a dorsoradial capsulodesis procedure. The procedure is done by imbricating the redundant TM joint dorsoradial ligament and capsule after reducing the joint by pronating the thumb. The dorsoradial capsulodesis is a reasonable reconstructive option for chronic TM joint instability and subluxation. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  19. The Orientation and Variation of the Acromioclavicular Ligament: An Anatomic Study.

    PubMed

    Nakazawa, Masataka; Nimura, Akimoto; Mochizuki, Tomoyuki; Koizumi, Masahiro; Sato, Tatsuo; Akita, Keiichi

    2016-10-01

    Several biomechanical studies have shown that the acromioclavicular (AC) ligament prevents posterior translation of the clavicle in the horizontal plane. In anatomy textbooks, however, the AC ligament is illustrated as running straight across the AC joint surface. The AC ligament does not run straight across the joint surface, and the configuration of the AC ligament may vary. Descriptive laboratory study. We used 16 pairs of shoulder girdles in this study. After identifying the AC ligament, we macroscopically investigated the orientation and attachment of the ligament and measured the angle between the ligament and the line perpendicular to the AC joint surface by using a digital goniometer. In addition, the AC joint inclination angle was measured, and the Spearman rank correlation coefficient between the joint inclination and the ligament angle was calculated. Finally, we sought to classify the AC ligament based on its configuration. Of the 16 pairs of specimens, 3 pairs of shoulders were histologically examined. The AC ligament was divided into 2 parts: a bundle at the superoposterior (SP) part and a bundle at the anteroinferior (AI) part of the joint. The well-developed SP bundle was consistent and ran obliquely at an average ± SD 30° ± 6° in relation to the AC joint surface, from the anterior part of the acromion to the posterior part of the distal clavicle. The joint inclination was 70° ± 12°, and a negative moderate correlation was found between the joint inclination and the ligament angle (P = .02, r = -0.46). In comparison, the AI bundle was thin and narrow, and it could be categorized into 3 types according to its various configurations. The AC ligament could be separated into the SP bundle and the AI bundle. The SP bundle ran posteriorly toward the distal clavicle from the acromion at an average angle of 30° to the joint surface. Anatomic reconstruction, based on the current findings in combination with findings regarding the coracoclavicular

  20. Quadriceps Strength Asymmetry After Anterior Cruciate Ligament Reconstruction Alters Knee Joint Biomechanics and Functional Performance at Time of Return to Activity.

    PubMed

    Palmieri-Smith, Riann M; Lepley, Lindsey K

    2015-07-01

    Quadriceps strength deficits are observed clinically after anterior cruciate ligament (ACL) injury and reconstruction and are often not overcome despite rehabilitation. Given that quadriceps strength may be important for achieving symmetrical joint biomechanics and promoting long-term joint health, determining the magnitude of strength deficits that lead to altered mechanics is critical. To determine if the magnitude of quadriceps strength asymmetry alters knee and hip biomechanical symmetry as well as functional performance and self-reported function. Cross-sectional study; Level of evidence, 3. A total of 73 patients were tested at the time they were cleared for return to activity after ACL reconstruction. Quadriceps strength and activation, scores on the International Knee Documentation Committee form, the hop for distance test, and sagittal plane lower extremity biomechanics were recorded while patients completed a single-legged hop. Patients with high and moderate quadriceps strength symmetry had larger central activation ratios as well as greater limb symmetry indices on the hop for distance compared with patients with low quadriceps strength symmetry (P < .05). Similarly, knee flexion angle and external moment symmetry were higher in the patients with high and moderate quadriceps symmetry compared with those with low symmetry (P < .05). Quadriceps strength was found to be associated with sagittal plane knee angle and moment symmetry (P < .05). Patients with low quadriceps strength displayed greater movement asymmetries at the knee in the sagittal plane. Quadriceps strength was related to movement asymmetries and functional performance. Rehabilitation after ACL reconstruction needs to focus on maximizing quadriceps strength, which likely will lead to more symmetrical knee biomechanics. © 2015 The Author(s).

  1. Hybrid spectral CT reconstruction

    PubMed Central

    Clark, Darin P.

    2017-01-01

    Current photon counting x-ray detector (PCD) technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID). In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM). Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with a spectral

  2. Quantification of dynamic posterior translation in modified bilateral Alexander views and correlation with clinical and radiological parameters in patients with acute acromioclavicular joint instability.

    PubMed

    Minkus, Marvin; Hann, Carmen; Scheibel, Markus; Kraus, Natascha

    2017-06-01

    Classification of AC-joint instability is based on radiologic evaluation of anteroposterior (a.p.) stress views of both shoulders, neglecting the horizontal component of instability. Recent studies have proposed an association of dynamic posterior translation (DPT) and inferior clinical results. The purpose of this study was to quantify DPT in modified Alexander views and correlate it with other radiological and clinical data. Thirty-two patients (4 f, 28 m, mean age 34.1) with acute AC-joint dislocation (16 = RW III, 16 = RW V) underwent radiological examination including bilateral a.p. stress views with measurement of the coracoclavicular distance (CCD) and bilateral modified Alexander views with different approaches to quantify DPT (overlapping area OA AC , overlapping length OL AC ). In addition, the Constant Score, Subjective Shoulder Value, Taft Score (TF), and the Acromioclavicular Joint Instability Score (ACJI) were obtained. In Rockwood (RW) type III injuries, a mean CCD of 15.8 (9.8-22.8) mm, OA AC of 50.9 (0-216.6) mm 2 , and OL AC of 6.5 (-4.7-17.9) mm were found. RW V patients showed a CCD of 23.1 (13.7-32.0) mm; OA AC 7.0 (0-92.3) mm 2 ; and OL AC -4.8 (-19.6-9.8) mm. Particularly in RW III the CCD, OA AC and OL AC revealed significant correlation with the ACJI (r = -0.64/r = 0.72/r = 0.68, p < 0.05) and TF (r = -0.56/r = 0.68/r = 0.51, p < 0.05). The proposed quantification tools for DPT were found to have a moderate-to-strong correlation with the score results, especially with AC-joint specific scores. RW type V injuries had a moderate correlation with clinical parameters (OA AC with ACJI: r = 0.44, p > 0.05 and OL AC with TF: r = -0.45, p > 0.05). Measuring the OL AC is a convenient way for quantifying DPT in modified Alexander views. It showed significant correlation with clinical scores, indicating the relevance of DPT in patients with AC-joint injury.

  3. Joint Dictionary Learning for Multispectral Change Detection.

    PubMed

    Lu, Xiaoqiang; Yuan, Yuan; Zheng, Xiangtao

    2017-04-01

    Change detection is one of the most important applications of remote sensing technology. It is a challenging task due to the obvious variations in the radiometric value of spectral signature and the limited capability of utilizing spectral information. In this paper, an improved sparse coding method for change detection is proposed. The intuition of the proposed method is that unchanged pixels in different images can be well reconstructed by the joint dictionary, which corresponds to knowledge of unchanged pixels, while changed pixels cannot. First, a query image pair is projected onto the joint dictionary to constitute the knowledge of unchanged pixels. Then reconstruction error is obtained to discriminate between the changed and unchanged pixels in the different images. To select the proper thresholds for determining changed regions, an automatic threshold selection strategy is presented by minimizing the reconstruction errors of the changed pixels. Adequate experiments on multispectral data have been tested, and the experimental results compared with the state-of-the-art methods prove the superiority of the proposed method. Contributions of the proposed method can be summarized as follows: 1) joint dictionary learning is proposed to explore the intrinsic information of different images for change detection. In this case, change detection can be transformed as a sparse representation problem. To the authors' knowledge, few publications utilize joint learning dictionary in change detection; 2) an automatic threshold selection strategy is presented, which minimizes the reconstruction errors of the changed pixels without the prior assumption of the spectral signature. As a result, the threshold value provided by the proposed method can adapt to different data due to the characteristic of joint dictionary learning; and 3) the proposed method makes no prior assumption of the modeling and the handling of the spectral signature, which can be adapted to different data.

  4. Effects of Initial Graft Tension on the Tibiofemoral Compressive Forces and Joint Position Following ACL Reconstruction

    PubMed Central

    Brady, Mark F.; Bradley, Michael P.; Fleming, Braden C.; Fadale, Paul D.; Hulstyn, Michael J.; Banerjee, Rahul

    2007-01-01

    Background The initial tension applied to an ACL graft at the time of fixation modulates knee motion and the tibiofemoral compressive loads. Purpose To establish the relationships between initial graft tension, tibiofemoral compressive force, and the neutral tibiofemoral position in the cadaver knee. Study Design Controlled Laboratory Study. Methods The tibiofemoral compressive forces and joint positions were determined in the ACL-intact knee at 0°, 20° and 90° knee flexion. The ACL was excised and reconstructed with a patellar tendon graft using graft tensions of 1, 15, 30, 60 and 90 N applied at 0°, 20° and 90° knee flexion. The compressive forces and neutral positions were compared between initial tension conditions and the ACL-intact knee. Results Increasing initial graft tension increased the tibiofemoral compressive forces. The forces in the medial compartment were 1.8 times those in the lateral compartment. The compressive forces were dependent on the knee angle at which the tension was applied. The greatest compressive forces occurred when the graft was tensioned with the knee in extension. An increase in initial graft tension caused the tibia to rotate externally compared to the ACL-intact knee. Increases in initial graft tension also caused a significant posterior translation of the tibia relative to the femur. Conclusions Different initial graft tension protocols produced predictable changes in the tibiofemoral compressive forces and joint positions. Clinical Relevance The tibiofemoral compressive force and neutral joint position were best replicated with a low graft tension (1–15 N) when using a patellar tendon graft. PMID:17218659

  5. Changes in surgical procedures for acromioclavicular joint dislocation over the past 30 years.

    PubMed

    Takase, Katsumi; Yamamoto, Kengo

    2013-10-01

    Generally, surgical treatment is recommended for Rockwood type 5 traumatic acromioclavicular joint dislocations. Since 1980, the authors have performed the modified Dewar procedure, the modified Cadenat procedure, and anatomical reconstruction of the coracoclavicular ligaments for this injury. The goal of this study was to determine the ideal surgical procedure for acromioclavicular joint dislocations by comparing these 3 procedures. The modified Dewar procedure was performed on 55 patients (Dewar group), the modified Cadenat procedure was performed on 73 patients (Cadenat group), and anatomical reconstruction of the coracoclavicular ligaments was performed on 11 patients (reconstruction group). According to the UCLA scoring system, therapeutic results averaged 27.3 points in the Dewar group, 28.2 in the Cadenat group, and 28.4 in the reconstruction group. The incidence of residual subluxation or dislocation in the acromioclavicular joint was evaluated at final radiographic follow-up. Subluxation occurred in 21 patients in the Dewar group, 18 in the Cadenat group, and 3 in the reconstruction group. Dislocation occurred in 3 patients in the Dewar group. Osteoarthritic changes in the acromioclavicular joint occurred in 20 patients in the Dewar group, 9 in the Cadenat group, and 1 in the reconstruction group. The modified Cadenat procedure can provide satisfactory therapeutic results and avoid postoperative failure or loss of reduction compared with the modified Dewar procedure. However, the modified Cadenat procedure does not anatomically restore the coracoclavicular ligaments. Anatomic restoration of both coracoclavicular ligaments can best restore acromioclavicular joint function. Copyright 2013, SLACK Incorporated.

  6. Single stage treatment of ankylosis of the temporomandibular joint using patient-specific total joint replacement and virtual surgical planning.

    PubMed

    Haq, Jahrad; Patel, Nishma; Weimer, Katherine; Matthews, N Shaun

    2014-04-01

    Ankylosis of the temporomandibular joint (TMJ) is a debilitating condition that can result in pain, trismus, and a poor quality of life. It can be caused by injury, infection, and rheumatoid disease. Current management includes gap arthroplasty, interpositional arthroplasty, and reconstruction. Traditionally, joints are reconstructed using stock implants, or the procedure is done in two stages with an additional computed tomography (CT) scan between the resective and reconstructive procedures and use of stereolithographic models to aid the design of the definitive prostheses. We describe a technique for the resection of ankylosis and reconstruction of the joint in a single operation using virtually designed custom-made implants. Five patients with ankylosis of the TMJ had a single stage operation with reconstruction between 2010 and 2012. All had preoperative high-resolution CT with contrast angiography. During an international web-based teleconference between the surgeon and the engineer a virtual resection of the ankylosis was done using the reconstructed CT images. The bespoke cutting guides and implants were designed virtually at the same time and were then manufactured precisely using computer-aided design and manufacture (CAD-CAM) over 6 weeks. After release of the ankylosis and reconstruction, the patients underwent an exercise regimen to improve mouth opening. Follow-up was for a minimum of 6 months. Four patients had one operation, and one patient had two. Median/Mean maximum incisal opening increased from 0.6mm before operation to 25 mm afterwards (range 23-27), and there was minimal surgical morbidity. This new method effectively treats ankylosis of the TMJ in a single stage procedure. Fewer operations and hospital stays, and the maintenance of overall clinical outcome are obvious advantages. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  7. Dynamic knee joint mechanics after anterior cruciate ligament reconstruction.

    PubMed

    Clarke, Sarah B; Kenny, Ian C; Harrison, Andrew J

    2015-01-01

    There is scarcity of information on the long-term adaptations in lower limb biomechanics during game-specific movements after anterior cruciate ligament (ACL) reconstruction. Particularly, variables such as knee abduction moments and transverse plane knee motion have not been studied during a game-specific landing and cutting task after ACL reconstruction. The purpose of this study was to compare the hip and knee mechanics between the ACL-reconstructed (ACLr) group and a healthy control group. Thirty-eight reconstructed athletes (18 ACLr, 18 control) participated in the study. Three-dimensional hip, knee, and ankle angles were calculated during a maximal drop jump land from a 0.30-m box and unanticipated cutting task at 45°. During the landing phase, ACLr participants had increased hip flexion (P < 0.003) and transverse plane knee range of motion (P = 0.027). During the cutting phase, the ACLr participant's previously injured limb had increased internal knee abduction moment compared with that of the control group (P = 0.032). No significant differences were reported between the previously injured and contralateral uninjured limb. Previously injured participants demonstrated higher knee abduction moment and transverse plane range of motion when compared with those of control participants during a game-specific landing and cutting task.

  8. Three-dimensional kinematics of the equine metacarpophalangeal joint using x-ray reconstruction of moving morphology - a pilot study.

    PubMed

    Childs, Bronwen A; Pugliese, Brenna R; Carballo, Cristina T; Miranda, Daniel L; Brainerd, Elizabeth L; Kirker-Head, Carl A

    2017-07-20

    X-ray reconstruction of moving morphology (XROMM) uses biplanar videoradiography and computed tomography (CT) scanning to capture three-dimensional (3D) bone motion. In XROMM, morphologically accurate 3D bone models derived from CT are animated with motion from videoradiography, yielding a highly accurate and precise reconstruction of skeletal kinematics. We employ this motion analysis technique to characterize metacarpophalangeal joint (MCPJ) motion in the absence and presence of protective legwear in a healthy pony. Our in vivo marker tracking precision was 0.09 mm for walk and trot, and 0.10 mm during jump down exercises. We report MCPJ maximum extension (walk: -27.70 ± 2.78° [standard deviation]; trot: -33.84 ± 4.94°), abduction/adduction (walk: 0.04 ± 0.24°; trot: -0.23 ± 0.35°) and external/internal rotations (walk: 0.30 ± 0.32°; trot: -0.49 ± 1.05°) indicating that the MCPJ in this pony is a stable hinge joint with negligible extra-sagittal rotations. No substantial change in MCPJ maximum extension angles or vertical ground reaction forces (GRFv) were observed upon application of legwear during jump down exercise. Neoprene boot application yielded -65.20 ± 2.06° extension (GRFv = 11.97 ± 0.67 N/kg) and fleece polo wrap application yielded -64.23 ± 1.68° extension (GRFv = 11.36 ± 1.66 N/kg), when compared to naked control (-66.11 ± 0.96°; GRFv = 12.02 ± 0.53 N/kg). Collectively, this proof of concept study illustrates the benefits and practical limitations of using XROMM to document equine MCPJ kinematics in the presence and absence of legwear.

  9. Joint reconstruction of dynamic PET activity and kinetic parametric images using total variation constrained dictionary sparse coding

    NASA Astrophysics Data System (ADS)

    Yu, Haiqing; Chen, Shuhang; Chen, Yunmei; Liu, Huafeng

    2017-05-01

    Dynamic positron emission tomography (PET) is capable of providing both spatial and temporal information of radio tracers in vivo. In this paper, we present a novel joint estimation framework to reconstruct temporal sequences of dynamic PET images and the coefficients characterizing the system impulse response function, from which the associated parametric images of the system macro parameters for tracer kinetics can be estimated. The proposed algorithm, which combines statistical data measurement and tracer kinetic models, integrates a dictionary sparse coding (DSC) into a total variational minimization based algorithm for simultaneous reconstruction of the activity distribution and parametric map from measured emission sinograms. DSC, based on the compartmental theory, provides biologically meaningful regularization, and total variation regularization is incorporated to provide edge-preserving guidance. We rely on techniques from minimization algorithms (the alternating direction method of multipliers) to first generate the estimated activity distributions with sub-optimal kinetic parameter estimates, and then recover the parametric maps given these activity estimates. These coupled iterative steps are repeated as necessary until convergence. Experiments with synthetic, Monte Carlo generated data, and real patient data have been conducted, and the results are very promising.

  10. Saipan and Joint Operations

    DTIC Science & Technology

    1990-02-12

    following postwar joint education objectives for ths armed forces: Objective i: To oroduce within each component of the armed forces a general knowledge...had acquired the pradtical knowledge to establieh::thvoe Joint educational goals which are as relevant today as when they were written. ENDNOTES 1...F2:", (- 1-1 1’A I’rn ,r’ lqA ,! Vim l ;` thO? C’~~~~~~~ a m in A i h9%t ý A din r, a INi m i t z% "h e haa I.z a:wn naval. +ac! lit! es, line~i n+f

  11. Validation of an improved helical diode array and dose reconstruction software using TG‐244 datasets and stringent dose comparison criteria

    PubMed Central

    Ahmed, Saeed; Nelms, Benjamin; Kozelka, Jakub; Zhang, Geoffrey; Moros, Eduardo

    2016-01-01

    The original helical ArcCHECK (AC) diode array and associated software for 3D measurement‐guided dose reconstruction were characterized and validated; however, recent design changes to the AC required that the subject be revisited. The most important AC change starting in 2014 was a significant reduction in the overresponse of diodes to scattered radiation outside of the direct beam, accomplished by reducing the amount of high‐Z materials adjacent to the diodes. This change improved the diode measurement accuracy, but in the process invalidated the dose reconstruction models that were assembled based on measured data acquired with the older version of the AC. A correction mechanism was introduced in the reconstruction software (3DVH) to accommodate this and potential future design changes without requiring updating model parameters. For each permutation of AC serial number and beam model, the user can define in 3DVH a single correction factor which will be used to compensate for the difference in the out‐of‐field response between the new and original AC designs. The exact value can be determined by minimizing the dose‐difference with an ionization chamber or another independent dosimeter. A single value of 1.17, corresponding to the maximum measured out‐of‐field response difference between the new and old AC, provided satisfactory results for all studied energies (6X, 15X, and flattening filter‐free 10XFFF). A library of standard cases recommended by the AAPM TG‐244 Report was used for reconstructed dose verification. The overall difference between reconstructed dose and an ion chamber in a water‐equivalent phantom in the targets was 0.0% ± 1.4% (1 SD). The reconstructed dose on a homogeneous phantom was also compared to a biplanar diode dosimeter (Delta4) using gamma analysis with 2% (local dose‐error normalization)/2 mm/10% cutoff criteria. The mean agreement rate was 96.7% ± 3.7%. For the plans common with the previous

  12. Validation of an improved helical diode array and dose reconstruction software using TG-244 datasets and stringent dose comparison criteria.

    PubMed

    Ahmed, Saeed; Nelms, Benjamin; Kozelka, Jakub; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir

    2016-11-08

    The original helical ArcCHECK (AC) diode array and associated software for 3D measurement-guided dose reconstruction were characterized and validated; however, recent design changes to the AC required that the subject be revisited. The most important AC change starting in 2014 was a significant reduction in the overresponse of diodes to scattered radiation outside of the direct beam, accom-plished by reducing the amount of high-Z materials adjacent to the diodes. This change improved the diode measurement accuracy, but in the process invalidated the dose reconstruction models that were assembled based on measured data acquired with the older version of the AC. A correction mechanism was intro-duced in the reconstruction software (3DVH) to accommodate this and potential future design changes without requiring updating model parameters. For each permutation of AC serial number and beam model, the user can define in 3DVH a single correction factor which will be used to compensate for the difference in the out-of-field response between the new and original AC designs. The exact value can be determined by minimizing the dose-difference with an ionization chamber or another independent dosimeter. A single value of 1.17, corresponding to the maximum measured out-of-field response difference between the new and old AC, provided satisfactory results for all studied energies (6X, 15X, and flatten-ing filter-free 10XFFF). A library of standard cases recommended by the AAPM TG-244 Report was used for reconstructed dose verification. The overall difference between reconstructed dose and an ion chamber in a water-equivalent phantom in the targets was 0.0% ± 1.4% (1 SD). The reconstructed dose on a homogeneous phantom was also compared to a biplanar diode dosimeter (Delta4) using gamma analysis with 2% (local dose-error normalization) / 2 mm / 10% cutoff criteria. The mean agreement rate was 96.7% ± 3.7%. For the plans common with the previous comparison, the mean agreement

  13. Current methods of burn reconstruction.

    PubMed

    Orgill, Dennis P; Ogawa, Rei

    2013-05-01

    After reading this article, the participant should be able to: 1. Explain the present challenges in reconstructive burn surgery. 2. Describe the most appropriate treatment methods and techniques for specific burn injury types, including skin grafts, dermal substitutes, and a variety of flap options. 3. Identify the appropriate use, advantages, and disadvantages of specific flaps in the treatment of burn injuries, including local, regional, superthin, prefabricated, prelaminated, and free flaps. Victims of thermal burns often form heavy scars and develop contractures around joints, inhibiting movement. As burns can occur in all cutaneous areas of the body, a wide range of reconstructive options have been utilized. Each method has advantages and disadvantages that must be considered by both patients and surgeons. The authors reviewed the literature for burn reconstruction and focused their discussion on areas that have been recently developed. They reviewed the mechanism of burn injury and discussed how this relates to the pathophysiology of the burn injury. Surgeons now have a wide array of plastic surgical techniques that can be used to treat burn victims. These range from skin grafts and local flaps to free flaps, prefabricated flaps, superthin flaps, and dermal scaffolds. Recent advances in burn reconstruction provide methods to decrease scar tissue and joint contractures. In the future, the authors hope that further developments in burn treatment will foster the development of new technologies that will allow site-specific reconstruction with minimal donor-site morbidity.

  14. Reconstruction of Hyaline Cartilage Deep Layer Properties in 3-Dimensional Cultures of Human Articular Chondrocytes.

    PubMed

    Nanduri, Vibudha; Tattikota, Surendra Mohan; T, Avinash Raj; Sriramagiri, Vijaya Rama Rao; Kantipudi, Suma; Pande, Gopal

    2014-06-01

    Articular cartilage (AC) injuries and malformations are commonly noticed because of trauma or age-related degeneration. Many methods have been adopted for replacing or repairing the damaged tissue. Currently available AC repair methods, in several cases, fail to yield good-quality long-lasting results, perhaps because the reconstructed tissue lacks the cellular and matrix properties seen in hyaline cartilage (HC). To reconstruct HC tissue from 2-dimensional (2D) and 3-dimensional (3D) cultures of AC-derived human chondrocytes that would specifically exhibit the cellular and biochemical properties of the deep layer of HC. Descriptive laboratory study. Two-dimensional cultures of human AC-derived chondrocytes were established in classical medium (CM) and newly defined medium (NDM) and maintained for a period of 6 weeks. These cells were suspended in 2 mm-thick collagen I gels, placed in 24-well culture inserts, and further cultured up to 30 days. Properties of chondrocytes, grown in 2D cultures and the reconstructed 3D cartilage tissue, were studied by optical and scanning electron microscopic techniques, immunohistochemistry, and cartilage-specific gene expression profiling by reverse transcription polymerase chain reaction and were compared with those of the deep layer of native human AC. Two-dimensional chondrocyte cultures grown in NDM, in comparison with those grown in CM, showed more chondrocyte-specific gene activity and matrix properties. The NDM-grown chondrocytes in 3D cultures also showed better reproduction of deep layer properties of HC, as confirmed by microscopic and gene expression analysis. The method used in this study can yield cartilage tissue up to approximately 1.6 cm in diameter and 2 mm in thickness that satisfies the very low cell density and matrix composition properties present in the deep layer of normal HC. This study presents a novel and reproducible method for long-term culture of AC-derived chondrocytes and reconstruction of cartilage

  15. Simultaneous maximum a posteriori longitudinal PET image reconstruction

    NASA Astrophysics Data System (ADS)

    Ellis, Sam; Reader, Andrew J.

    2017-09-01

    Positron emission tomography (PET) is frequently used to monitor functional changes that occur over extended time scales, for example in longitudinal oncology PET protocols that include routine clinical follow-up scans to assess the efficacy of a course of treatment. In these contexts PET datasets are currently reconstructed into images using single-dataset reconstruction methods. Inspired by recently proposed joint PET-MR reconstruction methods, we propose to reconstruct longitudinal datasets simultaneously by using a joint penalty term in order to exploit the high degree of similarity between longitudinal images. We achieved this by penalising voxel-wise differences between pairs of longitudinal PET images in a one-step-late maximum a posteriori (MAP) fashion, resulting in the MAP simultaneous longitudinal reconstruction (SLR) method. The proposed method reduced reconstruction errors and visually improved images relative to standard maximum likelihood expectation-maximisation (ML-EM) in simulated 2D longitudinal brain tumour scans. In reconstructions of split real 3D data with inserted simulated tumours, noise across images reconstructed with MAP-SLR was reduced to levels equivalent to doubling the number of detected counts when using ML-EM. Furthermore, quantification of tumour activities was largely preserved over a variety of longitudinal tumour changes, including changes in size and activity, with larger changes inducing larger biases relative to standard ML-EM reconstructions. Similar improvements were observed for a range of counts levels, demonstrating the robustness of the method when used with a single penalty strength. The results suggest that longitudinal regularisation is a simple but effective method of improving reconstructed PET images without using resolution degrading priors.

  16. AC Initiation System.

    DTIC Science & Technology

    An ac initiation system is described which uses three ac transmission signals interlocked for safety by frequency, phase, and power discrimination...The ac initiation system is pre-armed by the application of two ac signals have the proper phases, and activates a load when an ac power signal of the proper frequency and power level is applied. (Author)

  17. Limited distal clavicle excision of acromioclavicular joint osteoarthritis.

    PubMed

    Gokkus, K; Saylik, M; Atmaca, H; Sagtas, E; Aydin, A T

    2016-05-01

    Resection of the distal aspect of clavicle has a well-documented treatment modality in case of acromioclavicular joint osteoarthritis resistant to conservative treatment. Limited (mean ∼0.5cm distal end of clavicle resection) distal clavicle excision of A-C joint arthritis in cases resistant to conservative treatment may reduce the pain and improve the shoulder function. In this study, we retrospectively evaluated the results of limited distal clavicle excision of acromioclavicular joint osteoarthritis resistant to conservative treatment. All patients were evaluated by using the Visual Analogue Scale (VAS) and UCLA shoulder rating scale (University of California Los Angeles), either before surgery or final follow-up period for pain and functional results, respectively. A total of 110 patients (48 male, 62 female) with AC joint arthritis, treated between the years of 2008-2012, were retrospectively analyzed. A total of 30 patients (12 male, 18 female) who failed to show improvement with conservative treatment underwent limited surgical open excision of distal clavicle. The mean age of the study population was 52.5±1.2 years. The mean follow-up period was 27±1.3 months. The mean preoperative VAS score was 83.6±5.58 (range, 70-90) while mean VAS was 26.6±9.3 (range, 10-50) at the final follow-up. There was a statistically significant difference between pre- and postoperative VAS scores in patients who had treated by surgical approach (P<0.001). The mean UCLA score of the patients increased postoperatively from 11.5 (range, 9-14) to 29.2 (range, 27-32) at the final follow-up. There was a statistically significant difference between the two time periods with respect to UCLA scores (P<0.001). In patients with AC osteoarthritis resistant to conservative therapy, the hypothesized limited clavicle excision (mean ∼0.5cm distal end of clavicle resection with preserving coracoclavicular ligaments and inferior capsule) reduced the pain and improved the shoulder function

  18. Combined acromioclavicular joint dislocation and coracoid avulsion in an adult.

    PubMed

    Naik, Monappa; Tripathy, Sujit Kumar; Goyal, Saumitra; Rao, Sarath K

    2015-05-20

    Avulsion fracture of coracoid process with acromioclavicular joint dislocation is extremely rare. We report a case of coracoid avulsion with acromioclavicular disruption in a 24-year-old man who sustained injuries in a road traffic accident. Although acromioclavicular (AC) dislocation was obvious from an initial radiograph, coracoid avulsion was picked up in a CT scan. Open reduction and internal fixations of the coracoid with a 4 mm cannulated screw, an AC joint with two K-wires and an anchor suture, resulted in rapid recovery. The patient had complete range of shoulder movements at the end of 3 months and he resumed his professional activities. After 1 year, he had normal shoulder movement without any functional limitations. 2015 BMJ Publishing Group Ltd.

  19. Combined acromioclavicular joint dislocation and coracoid avulsion in an adult

    PubMed Central

    Naik, Monappa; Tripathy, Sujit Kumar; Goyal, Saumitra; Rao, Sarath K

    2015-01-01

    Avulsion fracture of coracoid process with acromioclavicular joint dislocation is extremely rare. We report a case of coracoid avulsion with acromioclavicular disruption in a 24-year-old man who sustained injuries in a road traffic accident. Although acromioclavicular (AC) dislocation was obvious from an initial radiograph, coracoid avulsion was picked up in a CT scan. Open reduction and internal fixations of the coracoid with a 4 mm cannulated screw, an AC joint with two K-wires and an anchor suture, resulted in rapid recovery. The patient had complete range of shoulder movements at the end of 3 months and he resumed his professional activities. After 1 year, he had normal shoulder movement without any functional limitations. PMID:25994429

  20. Anatomic mapping for surgical reconstruction of the proximal tibiofibular ligaments.

    PubMed

    See, Aaron; Bear, Russell R; Owens, Brett D

    2013-01-01

    Injury to the proximal tibiofibular joint is uncommon. Previous studies regarding the anatomy of this region have predominantly focused on joint orientation. As radiographic technology has advanced, later studies have attempted to evaluate the capsular anatomy. However, no reports specifically map the ligaments to this joint. The objectives of the current study were to define specific ligamentous structures that provide stability to the proximal tibiofibular joint, describe easily identifiable and reproducible surgical landmarks to aid in surgical reconstruction, and add to the understanding of the posterolateral structures of the knee previously described by other authors. The proximal tibiofibular joint ligaments were identified in 10 fresh-frozen cadaveric specimens. Average ligament length, width, and thickness and area of the footprints of the tibial and fibular attachments were measured. Distances from the ligament footprints to known anatomic landmarks (eg, Gerdy's tubercle, tibial articular surface, and fibular styloid) were also measured. The anterior ligament tibial attachment was a mean of 15.6 mm lateral and posterior to Gerdy's tubercle and 17.3 mm anterior and inferior from the fibular styloid. Posterior ligament tibial insertion was a mean of 15.7 mm inferior to the tibial articular surface on the tibial side and 14.2 mm medial and slightly inferior from the fibular styloid. Definable ligaments provide stability to the proximal tibiofibular joint and can be reconstructed in an anatomic fashion using the landmarks and parameters described. This information allows for an anatomic reconstruction of the proximal tibiofibular joint, which should provide patients with better outcomes and fewer postoperative sequelae. Copyright 2013, SLACK Incorporated.

  1. Hip joint biomechanics in those with and without post-traumatic knee osteoarthritis after anterior cruciate ligament injury.

    PubMed

    Wellsandt, E; Zeni, J A; Axe, M J; Snyder-Mackler, L

    2017-12-01

    Anterior cruciate ligament injury results in altered kinematics and kinetics in the knee and hip joints that persist despite surgical reconstruction and rehabilitation. Abnormal movement patterns and a history of osteoarthritis are risk factors for articular cartilage degeneration in additional joints. The purpose of this study was to determine if hip joint biomechanics early after anterior cruciate ligament injury and reconstruction differ between patients with and without post-traumatic knee osteoarthritis 5years after reconstruction. The study's rationale was that individuals who develop knee osteoarthritis after anterior cruciate ligament injury may also demonstrate large alterations in hip joint biomechanics. Nineteen athletes with anterior cruciate ligament injury completed standard gait analysis before (baseline) and after (post-training) extended pre-operative rehabilitation and at 6months, 1year, and 2years after reconstruction. Weightbearing knee radiographs were completed 5years after reconstruction to identify medial compartment osteoarthritis. Five of 19 patients had knee osteoarthritis at 5years after anterior cruciate ligament reconstruction. Patients with knee osteoarthritis at 5years walked with smaller sagittal plane hip angles (P: 0.043) and lower sagittal (P: 0.021) and frontal plane (P: 0.042) external hip moments in the injured limb before and after reconstruction compared to those without knee osteoarthritis. The current findings suggest hip joint biomechanics may be altered in patients who develop post-traumatic knee osteoarthritis. Further study is needed to confirm whether the risk of non-traumatic hip pathology is increased after anterior cruciate ligament injury and if hip joint biomechanics influence its development. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. [Reconstruction of the ear in the burns patient].

    PubMed

    Carrillo-Córdova, Jorge Raúl; Jiménez Murat, Yusef; Apellaniz-Campo, Armando; Bracho-Olvera, Hazel; Carrillo Esper, Raúl

    Face burns are a singular pathology with great functional and psychological impact in the patients suffering them. The ears play a fundamental role in personal interactions and damage to this organ results in physical and emotional distress. The reconstructive treatment of the burned ear is a challenge. Multiple procedures have been described to achieve success in the reconstruction of the burned ear; immediate reconstruction with autologous rib cartilage, secondary reconstruction, alloplastic material reconstruction, tissue expansion, skin grafts and also microvascular flaps are some of the most common procedures used in this patients. All these techniques focus on giving a natural appearance to the patient. Burns to the ears affect 30% of the patients with facial burns, they require an excellent treatment given by a multidisciplinary team. Copyright © 2017 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  3. Getting in shape: Reconstructing three-dimensional long-track speed skating kinematics by comparing several body pose reconstruction techniques.

    PubMed

    van der Kruk, E; Schwab, A L; van der Helm, F C T; Veeger, H E J

    2018-03-01

    In gait studies body pose reconstruction (BPR) techniques have been widely explored, but no previous protocols have been developed for speed skating, while the peculiarities of the skating posture and technique do not automatically allow for the transfer of the results of those explorations to kinematic skating data. The aim of this paper is to determine the best procedure for body pose reconstruction and inverse dynamics of speed skating, and to what extend this choice influences the estimation of joint power. The results show that an eight body segment model together with a global optimization method with revolute joint in the knee and in the lumbosacral joint, while keeping the other joints spherical, would be the most realistic model to use for the inverse kinematics in speed skating. To determine joint power, this method should be combined with a least-square error method for the inverse dynamics. Reporting on the BPR technique and the inverse dynamic method is crucial to enable comparison between studies. Our data showed an underestimation of up to 74% in mean joint power when no optimization procedure was applied for BPR and an underestimation of up to 31% in mean joint power when a bottom-up inverse dynamics method was chosen instead of a least square error approach. Although these results are aimed at speed skating, reporting on the BPR procedure and the inverse dynamics method, together with setting a golden standard should be common practice in all human movement research to allow comparison between studies. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Knee joint position sense ability in elite athletes who have returned to international level play following ACL reconstruction: A cross-sectional study.

    PubMed

    Relph, Nicola; Herrington, Lee

    2016-12-01

    Following an ACL injury, reconstruction (ACL-R) and rehabilitation, athletes may return to play with a proprioceptive deficit. However, literature is lacking to support this hypothesis in elite athletic groups who have returned to international levels of performance. It is possible the potentially heightened proprioceptive ability evidenced in athletes may negate a deficit following injury. The purpose of this study was to consider the effects of ACL injury, reconstruction and rehabilitation on knee joint position sense (JPS) on a group of elite athletes who had returned to international performance. Using a cross-sectional design ten elite athletes with ACL-R and ten controls were evaluated. JPS was tested into knee extension and flexion using absolute error scores. Average data with 95% confidence intervals between the reconstructed, contralateral and uninjured control knees were analyzed using t-tests and effect sizes. The reconstructed knee of the injured group demonstrated significantly greater angle of error scores when compared to the contralateral and uninjured control into knee flexion (p=0.0001, r=0.98) and knee extension (p=0.0001, r=0.91). There were no significant differences between the contralateral uninjured knee of the injured group and the uninjured control group. Elite athletes who have had an ACL injury, reconstruction, rehabilitation and returned to international play demonstrate lower JPS ability compared to control groups. It is unclear if this deficiency affects long-term performance or secondary injury and re-injury problems. In the future physical therapists should monitor athletes longitudinally when they return to play. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Medial Patellofemoral Ligament Reconstruction Using the Hamstring Tendon for Patellofemoral Joint Instability in an 81-Year-Old Female.

    PubMed

    Takahashi, Tsuneari; Takeshita, Katsushi

    2017-01-01

    Chronic patellofemoral instability occurs mainly in adolescent females and can also be induced by medial patellofemoral ligament (MPFL) injury. There are no case reports of MPFL reconstruction for chronic patellofemoral instability due to MPFL injury in aged populations. 81-year-old female presented with left knee pain, giving way, and patellar instability while climbing stairs, which continued for 18 months. Patellar apprehension test was positive, and roentgenogram showed lateral patellar subluxation. Conservative therapy was not successful; hence, we performed a lateral release and MPFL reconstruction surgery. After arthroscopic lateral release, the hamstring tendon was harvested, and a graft composite made of doubled hamstring tendon and polyester tape with a suspensory fixation device was prepared. Then, a femoral bone tunnel was constructed in a socket shape at the anatomical footprint of the MPFL. The graft was passed through the femoral tunnel, and free ends of the graft composite were sutured to the periosteum of the patella, using two suture anchors at 60° of knee flexion with patellar reduction. Physiotherapy was gradually started using a patella-stabilizing orthosis on the first postoperative day. Her Kujala score improved from 66 to 97 points, and Barthel index score improved from 70 to 100 points at 1 year after surgery. She neither developed patellofemoral joint OA nor had any recurrence of symptoms at the 5-year postoperative follow up. MPFL reconstruction using the hamstring tendon is an effective procedure for patients with chronic patellofemoral instability even after the age of 80 years.

  6. The EIT- and N- joint resonance lineshape asymmetry

    NASA Astrophysics Data System (ADS)

    Crescimanno, Michael; Hancox, Cindy; Hohensee, Michael; Phillips, David; Walsworth, Ron

    2008-03-01

    The solution of a quantum optics model for the joint EIT- and N- resonance explains the experimentally observed two-photon lineshape asymmetry as arising from interference and AC stark effects. This solution is evaluated for various light field intensities, detunings and couplings associated with experiments performed on the D1 and D2 transition of 87Rb. Because of its contribution to clock instability, lineshape asymmetry remains perhaps the main impediment to improving all-optical time standards based on the joint resonance.

  7. A Novel Image Compression Algorithm for High Resolution 3D Reconstruction

    NASA Astrophysics Data System (ADS)

    Siddeq, M. M.; Rodrigues, M. A.

    2014-06-01

    This research presents a novel algorithm to compress high-resolution images for accurate structured light 3D reconstruction. Structured light images contain a pattern of light and shadows projected on the surface of the object, which are captured by the sensor at very high resolutions. Our algorithm is concerned with compressing such images to a high degree with minimum loss without adversely affecting 3D reconstruction. The Compression Algorithm starts with a single level discrete wavelet transform (DWT) for decomposing an image into four sub-bands. The sub-band LL is transformed by DCT yielding a DC-matrix and an AC-matrix. The Minimize-Matrix-Size Algorithm is used to compress the AC-matrix while a DWT is applied again to the DC-matrix resulting in LL2, HL2, LH2 and HH2 sub-bands. The LL2 sub-band is transformed by DCT, while the Minimize-Matrix-Size Algorithm is applied to the other sub-bands. The proposed algorithm has been tested with images of different sizes within a 3D reconstruction scenario. The algorithm is demonstrated to be more effective than JPEG2000 and JPEG concerning higher compression rates with equivalent perceived quality and the ability to more accurately reconstruct the 3D models.

  8. Symposium introduction: the first joint American Chemical Society Agricultural and Food Chemistry Division and the American Chemical Society International Chemical Sciences Chapter in Thailand

    USDA-ARS?s Scientific Manuscript database

    The American Chemical Society (ACS) Agricultural and Food Chemistry Division (AGFD) and the ACS International Chemical Sciences Chapter in Thailand (ICSCT) worked together to stage the “1st Joint ACS AGFD - ACS ICSCT Symposium on Agricultural and Food Chemistry,” which was held in Bangkok, Thailand ...

  9. Restoration of horizontal stability in complete acromioclavicular joint separations: surgical technique and preliminary results.

    PubMed

    Li, Haoqing; Wang, Chuanshun; Wang, Jiandong; Wu, Kai; Hang, Donghua

    2013-11-13

    Our purpose was to investigate the clinical efficacy of arthroscope-assisted acromioclavicular ligament reconstruction in combination with double endobutton coracoclavicular ligament reconstruction for the treatment of complete acromioclavicular joint dislocation. During the period from February 2010 to October 2012, ten patients with Rockwood types IV and V acromioclavicular joint dislocation were hospitalized and nine were treated with acromioclavicular ligament reconstruction combined with double endobutton of coracoclavicular ligament reconstruction. The improvement in shoulder functions was assessed using a Constant score and visual analog scale (VAS) system. The mean follow-up period was 33.6 ± 5.4 months. The mean Constant scores improved from 25.2 ± 6.6 preoperatively to 92.4 ± 6.5 postoperatively, while the mean VAS score decreased from 5.9 ± 1.4 to 1.2 ± 0.9; significant differences were observed. The final follow-up revealed that excellent outcomes were achieved in eight patients and good outcome in two patients. Arthroscope-assisted acromioclavicular ligament reconstruction in combination with double endobutton of coracoclavicular ligament reconstruction is an effective approach for treatment of acute complete acromioclavicular joint dislocation.

  10. Digital tomosynthesis rendering of joint margins for arthritis assessment

    NASA Astrophysics Data System (ADS)

    Duryea, Jeffrey W.; Neumann, Gesa; Yoshioka, Hiroshi; Dobbins, James T., III

    2004-05-01

    PURPOSE: Rheumatoid arthritis (RA) of the hand is a significant healthcare problem. Techniques to accurately quantity the structural changes from RA are crucial for the development and prescription of therapies. Analysis of radiographic joint space width (JSW) is widely used and has demonstrated promise. However, radiography presents a 2D view of the joint. In this study we performed tomosynthesis reconstructions of proximal interphalangeal (PIP), and metacarpophalangeal (MCP) joints to measure the 3D joint structure. METHODS: We performed a reader study using simulated radiographs of 12 MCP and 12 PIP joints from skeletal specimens imaged with micro-CT. The tomosynthesis technique provided images of reconstructed planes with 0.75 mm spacing, which were presented to 2 readers with a computer tool. The readers were instructed to delineate the joint surfaces on tomosynthetic slices where they could visualize the margins. We performed a quantitative analysis of 5 slices surrounding the central portion of each joint. Reader-determined JSW was compared to a gold standard. As a figure of merit we calculated the average root-mean square deviation (RMSD). RESULTS: RMSD was 0.22 mm for both joints. For the individual joints, RMSD was 0.18 mm (MCP), and 0.26 mm (PIP). The reduced performance for the smaller PIP joints suggests that a slice spacing less than 0.75 mm may be more appropriate. CONCLUSIONS: We have demonstrated the capability of limited 3D rendering of joint surfaces using digital tomosynthesis. This technique promises to provide an improved method to visualize the structural changes of RA.

  11. Polarimetric image reconstruction algorithms

    NASA Astrophysics Data System (ADS)

    Valenzuela, John R.

    In the field of imaging polarimetry Stokes parameters are sought and must be inferred from noisy and blurred intensity measurements. Using a penalized-likelihood estimation framework we investigate reconstruction quality when estimating intensity images and then transforming to Stokes parameters (traditional estimator), and when estimating Stokes parameters directly (Stokes estimator). We define our cost function for reconstruction by a weighted least squares data fit term and a regularization penalty. It is shown that under quadratic regularization, the traditional and Stokes estimators can be made equal by appropriate choice of regularization parameters. It is empirically shown that, when using edge preserving regularization, estimating the Stokes parameters directly leads to lower RMS error in reconstruction. Also, the addition of a cross channel regularization term further lowers the RMS error for both methods especially in the case of low SNR. The technique of phase diversity has been used in traditional incoherent imaging systems to jointly estimate an object and optical system aberrations. We extend the technique of phase diversity to polarimetric imaging systems. Specifically, we describe penalized-likelihood methods for jointly estimating Stokes images and optical system aberrations from measurements that contain phase diversity. Jointly estimating Stokes images and optical system aberrations involves a large parameter space. A closed-form expression for the estimate of the Stokes images in terms of the aberration parameters is derived and used in a formulation that reduces the dimensionality of the search space to the number of aberration parameters only. We compare the performance of the joint estimator under both quadratic and edge-preserving regularization. The joint estimator with edge-preserving regularization yields higher fidelity polarization estimates than with quadratic regularization. Under quadratic regularization, using the reduced

  12. Arthroscopic-Assisted Triangular Fibrocartilage Complex Reconstruction.

    PubMed

    Chu-Kay Mak, Michael; Ho, Pak-Cheong

    2017-11-01

    Injury of the triangular fibrocartilage complex (TFCC) is a common cause of ulnar-sided wrist pain. Volar and dorsal radioulnar ligaments and their foveal insertion are the most important stabilizing components of the TFCC. In irreparable tears, anatomic reconstruction of the TFCC aims to restore normal biomechanics and stability of the distal radioulnar joint. We proposed a novel arthroscopic-assisted technique using a palmaris longus tendon graft. Arthroscopic-assisted TFCC reconstruction is a safe and effective approach with outcomes comparable to conventional open reconstruction and may result in a better range of motion from minimizing soft tissue dissection and subsequent scarring. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Association of fibrosis in the infrapatellar fat pad and degenerative cartilage change of patellofemoral joint after anterior cruciate ligament reconstruction.

    PubMed

    Yoon, Kyoung Ho; Tak, Dae Hyun; Ko, Taeg Su; Park, Sang Eon; Nam, Juhyun; Lee, Sang Hak

    2017-03-01

    The purpose of this study was to evaluate the prevalence and risk factor of cartilage degeneration of the patellofemoral joint (PFJ) that was diagnosed by second-look arthroscopy. One-hundred and seven patients who underwent ACL reconstruction were evaluated by preoperative MRI, postoperative MRI and second-look arthroscopy. Severity of infrapatellar fat pad (IPFP) fibrosis was evaluated by MRI at an average of 26months after ACL reconstruction. Cartilage degeneration was assessed by second-look arthroscopy at 29months. Twenty-five patients (24.0%) showed cartilage degeneration of the PFJ in second-look arthroscopy. Patients were divided into three groups according to severity of IPFP fibrosis of postoperative MRI (i.e. Group A, focal and incomplete band fibrosis, n=69; Group B, complete band fibrosis, n=31; and Group C, diffuse and infiltrated fibrosis, n=7). Cartilage degeneration of the PFJ was significantly worsened with more fibrosis formation of the IPFP (P<0.001). Other factors for instabilities (BMI, age, concomitant meniscal procedure, time from injury to reconstruction, severity of IPFP fibrosis at preoperative MRI and clinical scores) were not correlated with cartilage degeneration of the PFJ. The multivariate logistic regression analysis of degeneration of the PFJ after ACL reconstruction identified more severe fibrosis tissue formation of the IPFP and initial cartilage defect as significant predictors. More extensive fibrosis of the IPFP and initial cartilage defect may be related to further degenerative changes of the PFJ. Other factors did not affect cartilage degeneration of the PFJ, although the muscle strength, the individual activity level or the rehabilitation protocol was not evaluated in the short-term follow-up period. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Lower Limb Kinematics and Dynamic Postural Stability in Anterior Cruciate Ligament-Reconstructed Female Athletes

    PubMed Central

    Delahunt, Eamonn; Chawke, Mark; Kelleher, Judy; Murphy, Katie; Prendiville, Anna; Sweeny, Lauren; Patterson, Matt

    2013-01-01

    Context: Deficits in lower limb kinematics and postural stability are predisposing factors to the development of knee ligamentous injury. The extent to which these deficits are present after anterior cruciate ligament (ACL) reconstruction is still largely unknown. The primary hypothesis of the present study was that female athletes who have undergone ACL reconstruction and who have returned to sport participation would exhibit deficits in dynamic postural stability as well as deficiencies in hip- and knee-joint kinematics when compared with an age-, activity-, and sex-matched uninjured control group. Objective: To investigate dynamic postural stability as quantified by the Star Excursion Balance Test (SEBT) and simultaneous hip- and knee-joint kinematic profiles in female athletes who have undergone ACL reconstruction. Design: Descriptive laboratory study. Setting: University motion-analysis laboratory. Patients or Other Participants: Fourteen female athletes who had previously undergone ACL reconstruction (ACL-R) and 17 age- and sex-matched uninjured controls. Intervention(s): Each participant performed 3 trials of the anterior, posterior-medial, and posterior-lateral directional components of the SEBT. Main Outcome Measure(s): Reach distances for each directional component were quantified and expressed as a percentage of leg length. Simultaneous hip- and knee-joint kinematic profiles were recorded using a motion-analysis system. Results: The ACL-R group had decreased reach distances on the posterior-medial (P < .01) and posterior-lateral (P < .01) directional components of the SEBT. During performance of the directional components of the SEBT, ACL-R participants demonstrated altered hip-joint frontal-, sagittal-, and transverse-plane kinematic profiles (P < .05), as well as altered knee-joint sagittal-plane kinematic profiles (P < .05). Conclusions: Deficits in dynamic postural stability and concomitant altered hip- and knee-joint kinematics are present after ACL

  15. Open dislocation of the proximal interphalangeal joint of the little finger subsequent to chronic radial collateral ligament injury: a case report of primary ligament reconstruction with a half-slip of the flexor digitorum superficialis: Case Report.

    PubMed

    Wada, Kazuma; Hibino, Naohito; Kondo, Kenji; Yoshioka, Shinji; Terai, Tomoya; Henmi, Tatsuhiko; Sairyo, Koichi

    2015-01-01

    Open dislocation of the proximal interphalangeal (PIP) joint is relatively rare. We report a case of a 32-year-old man who had open dislocation of the PIP joint of the little finger while playing American football. He had a history of chronic radial collateral ligament injury. We reconstructed the radial collateral ligament with a half-slip of the flexor digitorum superficialis tendon.

  16. 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

  17. 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

  18. [EFFECTIVENESS COMPARISON OF CORACOCLAVICULAR LIGAMENT RECONSTRUCTION BETWEEN BY AUTOLOGOUS AND ALLOGENEIC TENDON GRAFTS COMBINED WITH HOOK PLATE FIXATION FOR TREATING ACROMIOCLAVICULAR JOINT DISLOCATION].

    PubMed

    Yin, Fei; Sun, Zhenzhong; Wei, Xuming; Liu, Xueguang; Zhou, Ming; Zhuang, Yin; Song, Sheng

    2016-05-08

    To compare the effectiveness of coracoclavicular ligament reconstruction between by using autologous plantaris tendon graft combined with hook plate fixation and allogeneic tendon graft combined with hook plate fixation for treating acromiocavicular joint dislocation. Thirty-three patients with acromioclavicular joint dislocation who accorded with the inclusion criteria between January 2013 and June 2014 were assigned into 2 groups. The patients were treated with autologous plantaris tendon graft combined with hook plate fixation in group A ( n =17), and with allogeneic tendon graft combined with hook plate fixation in group B ( n =16). Thirteen-one patients was followed up more than 12 months (15 in group A and 16 in group B). There was no significant difference in gender, age, cause of injury, sides, time between injury and surgery, and type of dislocation ( P >0.05). The assessments included operation time, hospitalization time, hospitalization expenses, shoulder range of motion, gap of acromioclavicular, Constant-Murley scores, and visual analogue scale (VAS) for pain. The operation time of group A was significantly longer than that of group B, and the hospitalization expense was significantly lower than that of group B ( P <0.05). There was no significant difference in hospitalization time ( t =1.046, P =0.316). The incisions healed by first intention, and hook plate was removed after 3 months. The mean follow-up time was 21.3 months (range, 19-34 months) in group A and was 23.7 months (range, 18-37 months) in group B. X-ray examination showed no osteolysis. There was no significant difference in gap of acromiocavicular between 2 groups at preoperation, 1 week after operation, and last follow-up ( P >0.05). No redislocation of acromioclavicular joint and rejection reaction occurred during follow-up. At last follow-up, there was no significant difference in shoulder range of motion, Constant-Murley score, and VAS score between 2 groups ( P >0

  19. Restoration of horizontal stability in complete acromioclavicular joint separations: surgical technique and preliminary results

    PubMed Central

    2013-01-01

    Background Our purpose was to investigate the clinical efficacy of arthroscope-assisted acromioclavicular ligament reconstruction in combination with double endobutton coracoclavicular ligament reconstruction for the treatment of complete acromioclavicular joint dislocation. Methods During the period from February 2010 to October 2012, ten patients with Rockwood types IV and V acromioclavicular joint dislocation were hospitalized and nine were treated with acromioclavicular ligament reconstruction combined with double endobutton of coracoclavicular ligament reconstruction. The improvement in shoulder functions was assessed using a Constant score and visual analog scale (VAS) system. Results The mean follow-up period was 33.6 ± 5.4 months. The mean Constant scores improved from 25.2 ± 6.6 preoperatively to 92.4 ± 6.5 postoperatively, while the mean VAS score decreased from 5.9 ± 1.4 to 1.2 ± 0.9; significant differences were observed. The final follow-up revealed that excellent outcomes were achieved in eight patients and good outcome in two patients. Conclusion Arthroscope-assisted acromioclavicular ligament reconstruction in combination with double endobutton of coracoclavicular ligament reconstruction is an effective approach for treatment of acute complete acromioclavicular joint dislocation. PMID:24225119

  20. AC-130 Employment

    DTIC Science & Technology

    2006-01-01

    1 AC -130 Employment Subject Area Aviation EWS 2006 Author Captain Robert Hornick, USMC Report Documentation Page Form ApprovedOMB No. 0704...00-2006 4. TITLE AND SUBTITLE AC -130 Employment 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER... AC -130 gunship is an aircraft that can provide all of these needs. Regrettably, there are too few AC -130’s in the inventory to cover all the needs

  1. PET image reconstruction using multi-parametric anato-functional priors

    NASA Astrophysics Data System (ADS)

    Mehranian, Abolfazl; Belzunce, Martin A.; Niccolini, Flavia; Politis, Marios; Prieto, Claudia; Turkheimer, Federico; Hammers, Alexander; Reader, Andrew J.

    2017-08-01

    In this study, we investigate the application of multi-parametric anato-functional (MR-PET) priors for the maximum a posteriori (MAP) reconstruction of brain PET data in order to address the limitations of the conventional anatomical priors in the presence of PET-MR mismatches. In addition to partial volume correction benefits, the suitability of these priors for reconstruction of low-count PET data is also introduced and demonstrated, comparing to standard maximum-likelihood (ML) reconstruction of high-count data. The conventional local Tikhonov and total variation (TV) priors and current state-of-the-art anatomical priors including the Kaipio, non-local Tikhonov prior with Bowsher and Gaussian similarity kernels are investigated and presented in a unified framework. The Gaussian kernels are calculated using both voxel- and patch-based feature vectors. To cope with PET and MR mismatches, the Bowsher and Gaussian priors are extended to multi-parametric priors. In addition, we propose a modified joint Burg entropy prior that by definition exploits all parametric information in the MAP reconstruction of PET data. The performance of the priors was extensively evaluated using 3D simulations and two clinical brain datasets of [18F]florbetaben and [18F]FDG radiotracers. For simulations, several anato-functional mismatches were intentionally introduced between the PET and MR images, and furthermore, for the FDG clinical dataset, two PET-unique active tumours were embedded in the PET data. Our simulation results showed that the joint Burg entropy prior far outperformed the conventional anatomical priors in terms of preserving PET unique lesions, while still reconstructing functional boundaries with corresponding MR boundaries. In addition, the multi-parametric extension of the Gaussian and Bowsher priors led to enhanced preservation of edge and PET unique features and also an improved bias-variance performance. In agreement with the simulation results, the clinical results

  2. [Tossy III injuries of the acromioclavicular joint. In what circumstances is surgery still justified? Personal results and literature review].

    PubMed

    Prokop, A; Helling, H J; Andermahr, J; Mönig, S; Rehm, K E

    2003-05-01

    In Germany AC-joint-dislocations type Tossy III are treated in most of the cases operatively. Over two times of period we treated AC-joint-dislocations type Tossy III with biodegradable PDS-cords. 54 patients were operated between 1989 and 1997 and followed up after 39 months. 87.5% of patients are satisfied with results and have 10.2 points at Taftscore. In this period we couldn't differentiated the results by Rockwood classification. 12 patients with Rockwood V were operated between 1998 and 2002 and followed up after 14 months. Excellent and good results were seen in 92% of cases. At Taftscore we seen 10.7 points. 3 patients with Rockwood III were treated conservative with 10.3 points and 3 patients were operated with 10.7 points at Taftscore. AC-joint dislocations should be classified to Rockwood. No differences were seen between operation and conservative treatment in Rockwood III in literature. We recommend operation with PDS cords with good results in Rockwood V.

  3. The Feasibility of Applying AC Driven Low-Temperature Plasma for Multi-Cycle Detonation Initiation

    NASA Astrophysics Data System (ADS)

    Zheng, Dianfeng

    2016-11-01

    Ignition is a key system in pulse detonation engines (PDE). As advanced ignition methods, nanosecond pulse discharge low-temperature plasma ignition is used in some combustion systems, and continuous alternating current (AC) driven low-temperature plasma using dielectric barrier discharge (DBD) is used for the combustion assistant. However, continuous AC driven plasmas cannot be used for ignition in pulse detonation engines. In this paper, experimental and numerical studies of pneumatic valve PDE using an AC driven low-temperature plasma igniter were described. The pneumatic valve was jointly designed with the low-temperature plasma igniter, and the numerical simulation of the cold-state flow field in the pneumatic valve showed that a complex flow in the discharge area, along with low speed, was beneficial for successful ignition. In the experiments ethylene was used as the fuel and air as oxidizing agent, ignition by an AC driven low-temperature plasma achieved multi-cycle intermittent detonation combustion on a PDE, the working frequency of the PDE reached 15 Hz and the peak pressure of the detonation wave was approximately 2.0 MPa. The experimental verifications of the feasibility in PDE ignition expanded the application field of AC driven low-temperature plasma. supported by National Natural Science Foundation of China (No. 51176001)

  4. [Efficacy of Sacroiliac Joint Anterior Approach with Double Reconstruction Plate and Computer Assisted Navigation Percutaneous Sacroiliac Screw for Treating Tile C1 Pelvic Fractures].

    PubMed

    Tan, Zhen; Fang, Yue; Zhang, Hui; Liu, Lei; Xiang, Zhou; Zhong, Gang; Huang, Fu-Guo; Wang, Guang-Lin

    2017-09-01

    To compare the efficacy of sacroiliac joint anterior approach with double reconstruction plate and computer assisted navigation percutaneous sacroiliac screw for treating Tile C1 pelvic fractures. Fifty patients with pelvic Tile C1 fractures were randomly divided into two groups ( n =25 for each) in the orthopedic department of West China Hospital of Sichuan University from December 2012 to November 2014. Patients in group A were treated by sacroiliac joint dislocation with anterior plate fixation. Patients in group B were treated with computerized navigation for percutaneous sacroiliac screw. The operation duration,intraoperative blood loss,incision length,and postoperative complications (nausea,vomiting,pulmonary infection,wound complications,etc.) were compared between the two groups. The postoperative fracture healing time,postoperative patient satisfaction,and postoperative fractures MATTA scores (to evaluate fracture reduction),postoperative MAJEED function scores,and SF36 scores of the patients were also recorded and compared. No significant differences in baseline characteristics were found between the two groups of patients. All of the patients in both groups had their operations successfully completed. Patients in group B had significantly shorter operations and lower intraoperative blood loss,incision length and postoperative complications than those in group A ( P <0.05). Patients in group B also had higher levels of satisfaction than those in group A ( P <0.05). No significant differences were found between the two groups in postoperative followup time,fracture healing time,postoperative MATTA scores,postoperative MAJEED function scores and SF36 scores ( P >0.05). Sacroiliac joint anterior approach with double reconstruction plate and computer assisted navigation percutaneous sacroiliac screws are both effective for treating Tile C1type pelvic fractures,with similar longterm efficacies. However,computer assisted navigation percutaneous sacroiliac screw

  5. The National Surgical Quality Improvement Program 30-Day Challenge: Microsurgical Breast Reconstruction Outcomes Reporting Reliability

    PubMed Central

    Chen, Austin D.; Kamali, Parisa; Chattha, Anmol S.; Bucknor, Alexandra; Cohen, Justin B.; Bletsis, Patrick P.; Flecha-Hirsch, Renata; Tobias, Adam M.; Lee, Bernard T.

    2018-01-01

    Background: The aim was to assess reliability of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) 30-day perioperative outcomes and complications for immediate, free-tissue transfer breast reconstruction by direct comparisons with our 30-day and overall institutional data, and assessing those that occur after 30 days. Methods: Data were retrieved for consecutive immediate, free-tissue transfer breast reconstruction patients from a single-institution database (2010–2015) and the ACS-NSQIP (2011–2014). Multiple logistic regressions were performed to compare adjusted outcomes between the 2 datasets. Results: For institutional versus ACS-NSQIP outcomes, there were no significant differences in surgical-site infection (SSI; 30-day, 3.6% versus 4.1%, P = 0.818; overall, 5.3% versus 4.1%, P = 0.198), wound disruption (WD; 30-day, 1.3% versus 1.5%, P = 0.526; overall, 2.3% versus 1.5%, P = 0.560), or unplanned readmission (URA; 30-day, 2.3% versus 3.3%, P = 0.714; overall, 4.6% versus 3.3%, P = 0.061). However, the ACS-NSQIP reported a significantly higher unplanned reoperation (URO) rate (30-day, 3.6% versus 9.5%, P < 0.001; overall, 5.3% versus 9.5%, P = 0.025). Institutional complications consisted of 5.3% SSI, 2.3% WD, 5.3% URO, and 4.6% URA, of which 25.0% SSI, 28.6% WD, 12.5% URO, and 7.1% URA occurred at 30–60 days, and 6.3% SSI, 14.3% WD, 18.8% URO, and 42.9% URA occurred after 60 days. Conclusion: For immediate, free-tissue breast reconstruction, the ACS-NSQIP may be reliable for monitoring and comparing SSI, WD, URO, and URA rates. However, clinicians may find it useful to understand limitations of the ACS-NSQIP for complications and risk factors, as it may underreport complications occurring beyond 30 days. PMID:29707443

  6. Double-button Fixation System for Management of Acute Acromioclavicular Joint Dislocation

    PubMed Central

    Torkaman, Ali; Bagherifard, Abolfazl; Mokhatri, Tahmineh; Haghighi, Mohammad Hossein Shabanpour; Monshizadeh, Siamak; Taraz, Hamid; Hasanvand, Amin

    2016-01-01

    Background: Surgical treatments for acromioclavicular (AC) joint dislocation present with some complications. The present study was designed to evaluate the double-button fixation system in the management of acute acromioclavicular joint dislocation. Methods: This cross sectional study, done between February 2011 to June 2014, consisted of 28 patients who underwent surgical management by the double-button fixation system for acute AC joint dislocation. Age, sex, injury mechanism, dominant hand, side with injury, length of follow up, time before surgery, shoulder and hand (DASH), constant and visual analogue scale (VAS) scores, and all complications of the cases during the follow up were recorded. Results: The mean age of patients was 33.23±6.7 years. Twenty four patients (85.71%) were male and four (14.28%) were female. The significant differences were observed between pre-operation VAS, constant shoulder scores and post-operation measurements. There were not any significant differences between right and left coracoclavicular, but two cases of heterotrophic ossifications were recorded. The mean follow-up time was 16.17±4.38 months. Conclusion: According to the results, the double-button fixation system for management of acute acromioclavicular joint dislocation has suitable results and minimal damage to the soft tissues surrounding the coracoclavicular ligaments. PMID:26894217

  7. Does well maintained graft provide consistent return to play after medial ulnar collateral ligament reconstruction of the elbow joint in elite baseball players?

    PubMed

    Park, Jin-Young; Oh, Kyung-Soo; Bahng, Seung-Chul; Chung, Seok-Won; Choi, Jin-Ho

    2014-06-01

    Several studies have reported the clinical outcomes of medial ulnar collateral ligament (MUCL) reconstruction of the elbow joint in throwing athletes, including the rate of return to sports. However, little has been known about the imaging outcomes after MUCL reconstruction. The aim of this study is to report the clinical and imaging outcomes after MUCL reconstruction using figure of eight fashion in the elite and professional baseball players. This study included 17 baseball players, who underwent MUCL reconstruction between July 2007 and May 2010. The average follow-up period was 48.6 months. Imaging assessment consisted of preoperative plain and stress radiographs, magnetic resonance imaging, and postoperative serial ultrasonography. The clinical assessments were composed of visual analogue scale (VAS) for pain, range of motion, and the Conway scale. The mean VAS score was 6.4 (range, 3 to 8) preoperatively and 2.2 (range, 0 to 4) postoperatively (p < 0.05). There were nine players (53%) classified as excellent who returned to sports at the same or higher level compared to preinjury. Serial ultrasonography revealed well-maintained grafts at 3 and 12 months in all of the players. Five out of 17 players showed decreased echogenecity in the common flexor tendon at 3 months, which was considered as remaining tissue swelling and resolved completely at 12 months. All grafts are well-maintained until 12-months based on the ultrasonographic findings, although only 53% of the players returned to preinjury level.

  8. Quadriceps Tendon Autograft Medial Patellofemoral Ligament Reconstruction.

    PubMed

    Fink, Christian; Steensen, Robert; Gföller, Peter; Lawton, Robert

    2018-06-01

    Critically evaluate the published literature related to quadriceps tendon (QT) medial patellofemoral ligament (MPFL) reconstruction. Hamstring tendon (HT) MPFL reconstruction techniques have been shown to successfully restore patella stability, but complications including patella fracture are reported. Quadriceps tendon (QT) reconstruction techniques with an intact graft pedicle on the patella side have the advantage that patella bone tunnel drilling and fixation are no longer needed, reducing risk of patella fracture. Several QT MPFL reconstruction techniques, including minimally invasive surgical (MIS) approaches, have been published with promising clinical results and fewer complications than with HT techniques. Parallel laboratory studies have shown macroscopic anatomy and biomechanical properties of QT are more similar to native MPFL than hamstring (HS) HT, suggesting QT may more accurately restore native joint kinematics. Quadriceps tendon MPFL reconstruction, via both open and MIS techniques, have promising clinical results and offer valuable alternatives to HS grafts for primary and revision MPFL reconstruction in both children and adults.

  9. Recent advances in computational mechanics of the human knee joint.

    PubMed

    Kazemi, M; Dabiri, Y; Li, L P

    2013-01-01

    Computational mechanics has been advanced in every area of orthopedic biomechanics. The objective of this paper is to provide a general review of the computational models used in the analysis of the mechanical function of the knee joint in different loading and pathological conditions. Major review articles published in related areas are summarized first. The constitutive models for soft tissues of the knee are briefly discussed to facilitate understanding the joint modeling. A detailed review of the tibiofemoral joint models is presented thereafter. The geometry reconstruction procedures as well as some critical issues in finite element modeling are also discussed. Computational modeling can be a reliable and effective method for the study of mechanical behavior of the knee joint, if the model is constructed correctly. Single-phase material models have been used to predict the instantaneous load response for the healthy knees and repaired joints, such as total and partial meniscectomies, ACL and PCL reconstructions, and joint replacements. Recently, poromechanical models accounting for fluid pressurization in soft tissues have been proposed to study the viscoelastic response of the healthy and impaired knee joints. While the constitutive modeling has been considerably advanced at the tissue level, many challenges still exist in applying a good material model to three-dimensional joint simulations. A complete model validation at the joint level seems impossible presently, because only simple data can be obtained experimentally. Therefore, model validation may be concentrated on the constitutive laws using multiple mechanical tests of the tissues. Extensive model verifications at the joint level are still crucial for the accuracy of the modeling.

  10. [COMPARISON OF FEMORAL CONDYLAR TWIST ANGLE IN THREE DIMENSIONAL RECONSTRUCTION DIGITAL MODELS OF KNEE JOINT BASED ON TWO DIMENSIONAL IMAGES OF MRI AND CT].

    PubMed

    Huang, Zan; Li, Yanlin; Hu, Meng; Li, Jian; You, Zhimin; Wang, Guoliang; He, Chuan

    2015-02-01

    To study the difference of femoral condylar twist angle (CTA) measurement in three dimensional (3-D) reconstruction digital models of human knee joint based on the two dimensional (2-D) images of MRI and CT so as to provide a reference for selecting the best method of CTA measurement in preoperative design for the femoral prosthesis rotational position. The CTA of 10 human cadaveric knee joint was measured in 3-D digital models based on MRI (group A), in 3-D digital models based on CT (group B), in the cadaveric knee joint with cartilage (group C), and in the cadaveric knee joint without cartilage (group D), respectively. The statistical analysis of the differences was made among the measurements of the CTA. The CTA values measured in 3-D digital models were (6.43 ± 0.53) degrees in group A and (3.31 ± 1.07) degrees in group B, showing significant difference (t = 10.235, P = 0.000). The CTA values measured in the cadaveric knee joint were (5.21 ± 1.28) degrees in group C and (3.33 ± 1.12) degrees in group D, showing significant difference (t = 5.770, P = 0.000). There was significant difference in the CTA values between group B and group C (t = 5.779, P = 0.000), but no significant difference was found between group A and group C (t = 3.219, P = 0.110). The CTA values measured in the 3-D digital models based on MRI are closer to the actual values measured in the knee joint with cartilage, and benefit for preoperative plan.

  11. Comparison of Bioabsorbable Interference Screws Composed of Poly-l-lactic Acid and Hydroxyapatite (PLLA-HA) to WasherLoc Tibial Fixation in Patients After Anterior Cruciate Ligament Reconstruction of the Knee Joint.

    PubMed

    Patkowski, Mateusz; Królikowska, Aleksandra; Reichert, Paweł

    2016-01-01

    The reconstruction of the anterior cruciate ligament (ACL) of the knee joint is a standard in ACL complete rupture treatment in athletes. One of the weakest points of this procedure is tibial fixation of grafts. The aim was, firstly, to evaluate patients 3-4 years after primary ACL reconstruction with the use of autologous ipsilateral STGR grafts and with tibial fixation using a bioabsorbable interference screw composed of PLLA-HA or WasherLoc, comparing the postoperative result to the preoperative condition and, secondly, to compare the results between the two groups of patients with different tibial fixation. Group I consisted of 20 patients with a bioabsorbable interference screw composed of PLLA-HA tibial fixation. In Group II, there were 22 patients after ACL reconstruction with the use of WasherLoc tibial fixation. The Lachman test, pivot-shift test, Lysholm Knee Scoring Scale and 2000 International Knee Documentation Committee (2000 IKDC) Subjective Knee Evaluation Form were used to evaluate the results. The intra-group comparison of the results of the 2000 IKDC Subjective Knee Evaluation Form and Lysholm Knee Scoring Scale obtained in the groups studied showed statistically significant differences between the evaluation performed preoperatively and postoperatively. The inter-group comparison of the results of the 2000 IKDC Subjective Knee Evaluation Form and Lysholm Knee Scoring Scale obtained postoperatively showed no statistically significant differences between the two groups. An evaluation 3-4 years after ACL reconstruction with the use of autologous ipsilateral STGR grafts demonstrated significant progress from the preoperative condition to the postoperative result in patients with tibial fixation using a bioabsorbable interference screw composed of PLLA-HA as well as in patients with WasherLoc tibial fixation. There were no differences found between the two groups of patients after ACL reconstruction in terms of manual stability testing or a

  12. Quantum-state reconstruction by maximizing likelihood and entropy.

    PubMed

    Teo, Yong Siah; Zhu, Huangjun; Englert, Berthold-Georg; Řeháček, Jaroslav; Hradil, Zdeněk

    2011-07-08

    Quantum-state reconstruction on a finite number of copies of a quantum system with informationally incomplete measurements, as a rule, does not yield a unique result. We derive a reconstruction scheme where both the likelihood and the von Neumann entropy functionals are maximized in order to systematically select the most-likely estimator with the largest entropy, that is, the least-bias estimator, consistent with a given set of measurement data. This is equivalent to the joint consideration of our partial knowledge and ignorance about the ensemble to reconstruct its identity. An interesting structure of such estimators will also be explored.

  13. Clavicular bone tunnel malposition leads to early failures in coracoclavicular ligament reconstructions.

    PubMed

    Cook, Jay B; Shaha, James S; Rowles, Douglas J; Bottoni, Craig R; Shaha, Steven H; Tokish, John M

    2013-01-01

    Modern techniques for the treatment of acromioclavicular (AC) joint dislocations have largely centered on free tendon graft reconstructions. Recent biomechanical studies have demonstrated that an anatomic reconstruction with 2 clavicular bone tunnels more closely matches the properties of native coracoclavicular (CC) ligaments than more traditional techniques. No study has analyzed tunnel position in regard to risk of early failure. To evaluate the effect of clavicular tunnel position in CC ligament reconstruction as a risk of early failure. Case series; Level of evidence, 4. A retrospective review was performed of a consecutive series of CC ligament reconstructions performed with 2 clavicular bone tunnels and a free tendon graft. The population was largely a young, active-duty military group of patients. Radiographs were analyzed for the maintenance of reduction and location of clavicular bone tunnels using a picture archiving and communication system. The distance from the lateral border of the clavicle to the center of each bone tunnel was divided by the total clavicular length to establish a ratio. Medical records were reviewed for operative details and functional outcome. Failure was defined as loss of intraoperative reduction. The overall failure rate was 28.6% (8/28) at an average of 7.4 weeks postoperatively. Comparison of bone tunnel position showed that medialized bone tunnels were a significant predictor for early loss of reduction for the conoid (a ratio of 0.292 vs 0.248; P = .012) and trapezoid bone tunnels (a ratio of 0.171 vs 0.128; P = .004); this correlated to an average of 7 to 9 mm more medial in the reconstructions that failed. Reconstructions performed with a conoid ratio of ≥0.30 were significantly more likely to fail (5/5, 100%) than were those performed lateral to a ratio of 0.30 (3/23, 13.0%) (P < .01). There were no failures when the conoid ratio was <0.25 (0/10, 0%). Conoid tunnel placement was also statistically significant for

  14. Sensory innervation of the temporomandibular joint in the mouse.

    PubMed

    Dreessen, D; Halata, Z; Strasmann, T

    1990-01-01

    The sensory innervation of the temporomandibular joints (TMJs) of 8 STR/IN mice was investigated by means of light and electron microscopy. Through the cutting of complete semithin sections in series it was possible to investigate the joints thoroughly. Additionally, one joint with its nerve supply was reconstructed three-dimensionally with a computerized three-dimensional programme. The reconstruction was based on one complete semithin section series. The joint's nerve supply originates from the nervus auriculotemporalis and additionally from motor branches of the n. mandibularis: n. massetericus, n. pterygoideus lateralis and the nn. temporales posteriores. The greatest number of nerve fibres and endings is located in the dorsolateral part of the joint capsule. They lie only in the stratum fibrosum and subsynovially. Neither the stratum synoviale nor the discus articularis contain any nerve fibres or endings, whereas the peri-articular loose connective tissue is richly innervated. The only type of nerve ending observed within the joint was the free nerve ending, which is assumed to serve not only as a nociceptor but also as a polymodal mechanoreceptor. Merely within the insertion of the musculus pterygoideus lateralis at the collum mandibulae single stretch receptors of the Ruffini type were observed. Ultrastructurally, they correspond to those described in the cat's knee joint. Neither lamellated nor nerve endings of the Golgi or Pacini type were observed in the joint or in the peri-articular connective tissue. The unexpected paucity of nerve fibres and endings in the TMJ itself of the mouse suggests that the afferent information from the joint is less important for position sense and movement than the afferent information from muscles, tendons and periodontal ligaments.

  15. Elastic cartilage reconstruction by transplantation of cultured hyaline cartilage-derived chondrocytes.

    PubMed

    Mizuno, M; Takebe, T; Kobayashi, S; Kimura, S; Masutani, M; Lee, S; Jo, Y H; Lee, J I; Taniguchi, H

    2014-05-01

    Current surgical intervention of craniofacial defects caused by injuries or abnormalities uses reconstructive materials, such as autologous cartilage grafts. Transplantation of autologous tissues, however, places a significant invasiveness on patients, and many efforts have been made for establishing an alternative graft. Recently, we and others have shown the potential use of reconstructed elastic cartilage from ear-derived chondrocytes or progenitors with the unique elastic properties. Here, we examined the differentiation potential of canine joint cartilage-derived chondrocytes into elastic cartilage for expanding the cell sources, such as hyaline cartilage. Articular chondrocytes are isolated from canine joint, cultivated, and compared regarding characteristic differences with auricular chondrocytes, including proliferation rates, gene expression, extracellular matrix production, and cartilage reconstruction capability after transplantation. Canine articular chondrocytes proliferated less robustly than auricular chondrocytes, but there was no significant difference in the amount of sulfated glycosaminoglycan produced from redifferentiated chondrocytes. Furthermore, in vitro expanded and redifferentiated articular chondrocytes have been shown to reconstruct elastic cartilage on transplantation that has histologic characteristics distinct from hyaline cartilage. Taken together, cultured hyaline cartilage-derived chondrocytes are a possible cell source for elastic cartilage reconstruction. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  16. False ankylosis of the temporomandibular joint in a cat. Correction by partial zygomatic arch resection.

    PubMed

    Larguier, L; Jamet, N

    2015-01-01

    To describe the use of two-dimensional computer-assisted tomography (CT) with three-dimensional (3D) reconstruction in the diagnosis and planning of surgical treatment of a case of false ankylosis of the temporomandibular joint. A young European Shorthaired cat was presented with the complaint of inability to eat and open its jaws. A CT scan with 3D reconstruction allowed visualization of the lesion which was causing extra-articular ankylosis of the temporomandibular joint. Surgery was performed to resect an osseous lesion of the zygomatic arch, thus freeing the temporomandibular joint. Postoperative physical therapy was initiated immediately following surgery, and then carried out by the owner with a one year follow-up. Clinical examination of the cat was performed during regular office visits (at 1 month and 3 months following surgery), which allowed objective assessment of postoperative recuperation. At the end of a year, the owners reported that the cat had maintained sufficient jaw opening without any signs consistent with chronic pain. Computed tomography scan with 3D reconstruction allowed planning of the surgical correction of extra-articular ankylosis of the temporomandibular joint, and in this case condylectomy was avoided, since temporomandibular joint range-of-motion was maintained.

  17. Effect of changes of femoral offset on abductor and joint reaction forces in total hip arthroplasty.

    PubMed

    Rüdiger, Hannes A; Guillemin, Maïka; Latypova, Adeliya; Terrier, Alexandre

    2017-11-01

    Anatomical reconstruction in total hip arthroplasty (THA) allows for physiological muscle function, good functional outcome and implant longevity. Quantitative data on the effect of a loss or gain of femoral offset (FO) are scarce. The aim of this study was to quantitatively describe the effect of FO changes on abductor moment arms, muscle and joint reactions forces. THA was virtually performed on 3D models built from preoperative CT scans of 15 patients undergoing THA. Virtual THA was performed with a perfectly anatomical reconstruction, a loss of 20% of FO (-FO), and a gain of 20% of FO (+FO). These models were combined with a generic musculoskeletal model (OpenSim) to predict moment arms, muscle and joint reaction forces during normal gait cycles. In average, with -FO reconstructions, muscle moment arms decreased, while muscle and hip forces increased significantly (p < 0.001). We observed the opposite with +FO reconstructions. Gluteus medius was more affected than gluteus minimus. -FO had more effect than +FO. A change of 20% of FO induced an average change 8% of abductor moment arms, 16% of their forces, and 6% of the joint reaction force. To our knowledge, this is the first report providing quantitative data on the effect of FO changes on muscle and joint forces during normal gait. A decrease of FO necessitates an increase of abductor muscle force to maintain normal gait, which in turn increases the joint reaction force. This effect underscores the importance of an accurate reconstruction of the femoral offset.

  18. Calcaneocuboid joint instability: a novel operative technique for anatomic reconstruction.

    PubMed

    Lohrer, Heinz; Arentz, Sabine

    2004-05-01

    A case history of a 13-year-old female national top-level gymnast, suffering from calcaneocuboid joint instability, is presented. The procedure was done as an anatomic repair by capsular reefing, which was augmented using a local periosteal flap. Initially, the athlete twisted her ankle. Clinical investigation revealed no sign of a lateral ankle ligament injury, but following this initial examination, recurrent giving-way of the foot occurred. She additionally felt significant but diffuse pain on the lateral side of the foot during loading in training and competition. For 2 months she was unable to run and conservative treatment failed. Diagnosis of a calcaneocuboid instability was established 4 months after the initial lesion by clinical and x-ray stress examination of the calcaneocuboid joint. Open surgery was successfully performed. Early functional posttreatment was done and the patient returned to full high-level gymnastics ability 16 weeks after surgery. Two years later, a similar injury occurred to the opposite calcaneocuboid joint and the same operative procedure again led to full sports ability.

  19. Joint Line Reconstruction in Navigated Total Knee Arthroplasty Revision

    ClinicalTrials.gov

    2012-05-16

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

  20. Hazardous and Medical Waste Destruction Using the AC Plasmatron Final Report CRADA No. TC-1560-98

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Caplan, M.; Bucher, K.; Tulupov, A.

    The goal of this project was to develop a prototype medical waste destruction facility based on the AC plasma torch capable of processing 150 kg of waste per hour while satisfying US EPA emission standards. The project was to provide the first opportunity for a joint U.S.-Russian project using an AC Plasma Torch in a hazardous waste destruction system to be assembled and operated in the U.S. thus promoting the commercialization in the U.S. of this joint U.S.-Russian developed technology. This project was a collaboration between the Russian Institute Soliton- NTT, the U.S industrial partner Scientific Utilization Inc. (SUI) andmore » Lawrence Livermore National Laboratory ( LLNL). The project was funded by DOE for a total of $1.2 million with $600K for allocated for Phase I and $600K for Phase II. The Russian team received about $800K over the two (2) year period while LLNL received $400K. SUI was to provide in kind matching funds totaling $1.2 million.« less

  1. Management of chronic unstable acromioclavicular joint injuries.

    PubMed

    Cisneros, Luis Natera; Reiriz, Juan Sarasquete

    2017-12-01

    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.

  2. 3D confocal reconstruction of gene expression in mouse.

    PubMed

    Hecksher-Sørensen, J; Sharpe, J

    2001-01-01

    Three-dimensional computer reconstructions of gene expression data will become a valuable tool in biomedical research in the near future. However, at present the process of converting in situ expression data into 3D models is a highly specialized and time-consuming procedure. Here we present a method which allows rapid reconstruction of whole-mount in situ data from mouse embryos. Mid-gestation embryos were stained with the alkaline phosphotase substrate Fast Red, which can be detected using confocal laser scanning microscopy (CLSM), and cut into 70 microm sections. Each section was then scanned and digitally reconstructed. Using this method it took two days to section, digitize and reconstruct the full expression pattern of Shh in an E9.5 embryo (a 3D model of this embryo can be seen at genex.hgu.mrc.ac.uk). Additionally we demonstrate that this technique allows gene expression to be studied at the single cell level in intact tissue.

  3. Enhanced knee joint function due to accelerated rehabilitation exercise after anterior cruciate ligament reconstruction surgery in Korean male high school soccer players.

    PubMed

    Lee, Myungchun; Sung, Dong Jun; Lee, Joohyung; Oh, Inyoung; Kim, Sojung; Kim, Seungho; Kim, Jooyoung

    2016-02-01

    This study was conducted on Korean male high school soccer players who underwent anterior cruciate ligament reconstruction (ACLR) to identify the effects of an accelerated rehabilitation exercise (ARE) program on knee joint isometric strength, thigh circumference, Lysholm score, and active balance agility. We assigned eight test participants each to a physical therapy group (PTG) and an accelerated rehabilitation exercise group (AREG), and compared differences between the groups. Both the PTG and AREG showed significant increases in 30° away and 60° toward isometric strength after treatment. In addition, significant differences were observed in these strength tests between the two groups. Both groups also showed significant increases in thigh circumference, Lysholm score, and active balance agility after treatment, but no significant differences were observed between the two groups. We conclude that the ARE treatment was more effective for improving isometric strength of the knee joint than that of physical therapy, and that an active rehabilitation exercise program after ACLR had positive effects on recovery performance of patients with an ACL injury and their return to the playing field.

  4. Recent Advances in Computational Mechanics of the Human Knee Joint

    PubMed Central

    Kazemi, M.; Dabiri, Y.; Li, L. P.

    2013-01-01

    Computational mechanics has been advanced in every area of orthopedic biomechanics. The objective of this paper is to provide a general review of the computational models used in the analysis of the mechanical function of the knee joint in different loading and pathological conditions. Major review articles published in related areas are summarized first. The constitutive models for soft tissues of the knee are briefly discussed to facilitate understanding the joint modeling. A detailed review of the tibiofemoral joint models is presented thereafter. The geometry reconstruction procedures as well as some critical issues in finite element modeling are also discussed. Computational modeling can be a reliable and effective method for the study of mechanical behavior of the knee joint, if the model is constructed correctly. Single-phase material models have been used to predict the instantaneous load response for the healthy knees and repaired joints, such as total and partial meniscectomies, ACL and PCL reconstructions, and joint replacements. Recently, poromechanical models accounting for fluid pressurization in soft tissues have been proposed to study the viscoelastic response of the healthy and impaired knee joints. While the constitutive modeling has been considerably advanced at the tissue level, many challenges still exist in applying a good material model to three-dimensional joint simulations. A complete model validation at the joint level seems impossible presently, because only simple data can be obtained experimentally. Therefore, model validation may be concentrated on the constitutive laws using multiple mechanical tests of the tissues. Extensive model verifications at the joint level are still crucial for the accuracy of the modeling. PMID:23509602

  5. Interpositional arthroplasty versus reconstruction arthroplasty for temporomandibular joint ankylosis: A systematic review and meta-analysis.

    PubMed

    Ma, Junli; Jiang, Hua; Liang, Limin

    2015-09-01

    Interpositional arthroplasty (IA) and reconstruction arthroplasty (RA) are widely used in treating temporomandibular joint ankylosis (TMJA). But the reported clinical outcomes are controversial, the debate over which one is better remains. The Pubmed, EMBASE, OVID EBM Reviews, and Web of science were searched up to Oct 11 2014 without limitation on year, language. Only randomized controlled trials and observational cohort studies with a follow-up of at least 12 months were included. A total of 8 retrospective cohort studies with 234 patients with TMJA were included in metaanalysis. Pooled analysis showed no significant differences in reankylosis (RD: -0.00; 95% CI: -0.08, 0.07; Z=0.06; P =0.95; I(2) =0%), and maximum incisal opening (MD=0.99; 95% CI: -1.43, 3.4, Z=0.8, p=0.42; I(2) =74%) between the IA and RA groups. IA and RA could produce similar outcomes in treating TMJA regarding to rankylosis and maximum incisal opening. Other postoperative complications, such as overgrowth of cartilage, malocclusion and the status of facial development should be evaluated more thoroughly. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  6. Alternative standardization approaches to improving streamflow reconstructions with ring-width indices of riparian trees

    USGS Publications Warehouse

    Meko, David M.; Friedman, Jonathan M.; Touchan, Ramzi; Edmondson, Jesse R.; Griffin, Eleanor R.; Scott, Julian A.

    2015-01-01

    Old, multi-aged populations of riparian trees provide an opportunity to improve reconstructions of streamflow. Here, ring widths of 394 plains cottonwood (Populus deltoids, ssp. monilifera) trees in the North Unit of Theodore Roosevelt National Park, North Dakota, are used to reconstruct streamflow along the Little Missouri River (LMR), North Dakota, US. Different versions of the cottonwood chronology are developed by (1) age-curve standardization (ACS), using age-stratified samples and a single estimated curve of ring width against estimated ring age, and (2) time-curve standardization (TCS), using a subset of longer ring-width series individually detrended with cubic smoothing splines of width against year. The cottonwood chronologies are combined with the first principal component of four upland conifer chronologies developed by conventional methods to investigate the possible value of riparian tree-ring chronologies for streamflow reconstruction of the LMR. Regression modeling indicates that the statistical signal for flow is stronger in the riparian cottonwood than in the upland chronologies. The flow signal from cottonwood complements rather than repeats the signal from upland conifers and is especially strong in young trees (e.g. 5–35 years). Reconstructions using a combination of cottonwoods and upland conifers are found to explain more than 50% of the variance of LMR flow over a 1935–1990 calibration period and to yield reconstruction of flow to 1658. The low-frequency component of reconstructed flow is sensitive to the choice of standardization method for the cottonwood. In contrast to the TCS version, the ACS reconstruction features persistent low flows in the 19th century. Results demonstrate the value to streamflow reconstruction of riparian cottonwood and suggest that more studies are needed to exploit the low-frequency streamflow signal in densely sampled age-stratified stands of riparian trees.

  7. Anatomy and Biomechanics of the Finger Proximal Interphalangeal Joint.

    PubMed

    Pang, Eric Quan; Yao, Jeffrey

    2018-05-01

    A complete understanding of the normal anatomy and biomechanics of the proximal interphalangeal joint is critical when treating pathology of the joint as well as in the design of new reconstructive treatments. The osseous anatomy dictates the principles of motion at the proximal interphalangeal joint. Subsequently, the joint is stabilized throughout its motion by the surrounding proximal collateral ligament, accessory collateral ligament, and volar plate. The goal of this article is to review the normal anatomy and biomechanics of the proximal interphalangeal joint and its associated structures, most importantly the proper collateral ligament, accessory collateral ligament, and volar plate. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Joint radius-length distribution as a measure of anisotropic pore eccentricity: an experimental and analytical framework.

    PubMed

    Benjamini, Dan; Basser, Peter J

    2014-12-07

    In this work, we present an experimental design and analytical framework to measure the nonparametric joint radius-length (R-L) distribution of an ensemble of parallel, finite cylindrical pores, and more generally, the eccentricity distribution of anisotropic pores. Employing a novel 3D double pulsed-field gradient acquisition scheme, we first obtain both the marginal radius and length distributions of a population of cylindrical pores and then use these to constrain and stabilize the estimate of the joint radius-length distribution. Using the marginal distributions as constraints allows the joint R-L distribution to be reconstructed from an underdetermined system (i.e., more variables than equations), which requires a relatively small and feasible number of MR acquisitions. Three simulated representative joint R-L distribution phantoms corrupted by different noise levels were reconstructed to demonstrate the process, using this new framework. As expected, the broader the peaks in the joint distribution, the less stable and more sensitive to noise the estimation of the marginal distributions. Nevertheless, the reconstruction of the joint distribution is remarkably robust to increases in noise level; we attribute this characteristic to the use of the marginal distributions as constraints. Axons are known to exhibit local compartment eccentricity variations upon injury; the extent of the variations depends on the severity of the injury. Nonparametric estimation of the eccentricity distribution of injured axonal tissue is of particular interest since generally one cannot assume a parametric distribution a priori. Reconstructing the eccentricity distribution may provide vital information about changes resulting from injury or that occurred during development.

  9. Reconstruction of equilibrium trajectories during whole-body movements.

    PubMed

    Domen, K; Latash, M L; Zatsiorsky, V M

    1999-03-01

    The framework of the equilibrium-point hypothesis was used to reconstruct equilibrium trajectories (ETs) of the ankle, hip and body center of mass during quick voluntary hip flexions ('Japanese courtesy bow') by standing subjects. Different spring loads applied to the subject's back were used to introduce smooth perturbations that are necessary to reconstruct ETs based on a series of trials at the same task. Time patterns of muscle torques were calculated using inverse dynamics techniques. A second-order linear model was employed to calculate the instantaneous position of the spring-like joint or center of mass characteristic at different times during the movement. ETs of the joints and of the center of mass had significantly different shapes from the actual trajectories. Integral measures of electromyographic bursts of activity in postural muscles demonstrated a relation to muscle length corresponding to the equilibrium-point hypothesis.

  10. [Perineal reconstruction: Salvage surgery with 2flaps technique].

    PubMed

    Jiménez Gómez, Marta; Navarro-Sánchez, Antonio; Lima Sánchez, Jaime; Hernández Hernández, Juan Ramón

    2017-12-01

    The principles of perineal reconstructive surgery comprise adequate filling of the defect along with stable and durable skin coverage, with a low morbidity rate. Two-flap perineal reconstruction is a simple, fast and reliable technique that uses a single donor site. This improves scar position with low morbidity. It is based in the use of 2flaps; one flap fills the defect with a «turn over» technique and the other is a rotation - advancement flap for skin coverage. A 52-year-old male diagnosed with Lynch syndrome who underwent laparoscopic abdominoperineal amputation for adenocarcinoma of the lower rectum and developed recurrence 2years later over the perineal scar that required radical resection and perineal reconstruction. The use of this approach facilitates perineal reconstruction and enables treatment of patients with large and complex defects in frequently irradiated tissues where wound dehiscence and infection are common. Copyright © 2017 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  11. Reconstruction of the trapeziometacarpal joint in inflammatory joint disease using interposition of autologous tendon or poly-L-D-lactic acid implants: a prospective clinical trial.

    PubMed

    Tiihonen, Raine P; Skyttä, Eerik T; Kaarela, Kalevi; Ikävalko, Mikko; Belt, Eero A

    2012-04-01

    Interposition arthroplasty with bioreplaceable poly-L-D-lactic acid (PLDLA) implants has yielded promising results in reconstruction of rheumatoid hands. In this prospective clinical study we compared the PLDLA implant arthroplasty (n = 17) with that of tendon interposition (n = 12) for destruction of the trapeziometacarpal joint in arthritic patients. There was no significant difference between the two groups preoperatively. At one-year follow-up, the mean pain and function scores were 5 and 13 in the PLDLA group, and 19 and 43 in the tendon interposition group, respectively. At one-year follow-up the visual analogue scale (VAS) for function of the PLDLA group differed significantly from that of the tendon interposition group (p = 0.03). This difference was not found at three months postoperatively, and disappeared again at two-year follow-up. Otherwise, no significant difference was found between the groups in the pain or function scores, functional tests, or range of movement. Bioreplaceable interposition arthroplasty works at least as well as tendon interposition. The operation is easier.

  12. The morphological characteristics of the antebrachiocarpal joint of the cheetah (Acinonyx jubatus).

    PubMed

    Ohale, L O C; Groenewald, H B

    2003-03-01

    A morphological study of the structures of the antebrachiocarpal (AC) joint of the cheetah was carded out by dissection of eight forelimbs obtained from four adult cheetahs culled from the Kruger National Park, Republic of South Africa. The aim was to evaluate the deviations of this joint from the normal feline pattern and to consider their possible relationship to the cheetah's adaptation to speed. Although published data on the AC joint of the other felids show general resemblance to that of the cheetah, there are nevertheless slight, but significant variations and modifications which tend to suggest adaptation to speed. The shafts of the radius and ulna of the cheetah are relatively straight and slender, with poorly developed distal ends. The ulnar notch is reduced to a very shallow concavity while the corresponding ulnar facet is a barely noticeable convexity, separated from the distal ulnar articular facet by an ill-defined groove. The movement of the distal radio-ulnar joint is highly restricted by the presence of a fibro-cartilaginous structure and a strong interrosseous membrane, limiting pronation and supination normally achieved by the rotation of the radius around the ulna. The extensor grooves at the distal extremity of the radius are deep and narrow and are guarded by prominent ridges. A thick extensor retinaculum anchors the strong extensor tendons in these grooves. The distal articular surface of the radius is concave in all directions except at the point where it moves into its stylold process. At this point it is convex in the dorsopalmar direction, with a surface that is rather deep and narrow. The proximal row of carpal bones presents a strongly convex surface, which is more pronounced in the dorsopalmar direction with the greatest convexity on the lateral aspect. Medially, there is a ridge-like concavity across the base of the tubercle, which rocks on the flexor surface of the radius, limiting excessive flexion as well as restricting lateral

  13. Single and Multiple Object Tracking Using a Multi-Feature Joint Sparse Representation.

    PubMed

    Hu, Weiming; Li, Wei; Zhang, Xiaoqin; Maybank, Stephen

    2015-04-01

    In this paper, we propose a tracking algorithm based on a multi-feature joint sparse representation. The templates for the sparse representation can include pixel values, textures, and edges. In the multi-feature joint optimization, noise or occlusion is dealt with using a set of trivial templates. A sparse weight constraint is introduced to dynamically select the relevant templates from the full set of templates. A variance ratio measure is adopted to adaptively adjust the weights of different features. The multi-feature template set is updated adaptively. We further propose an algorithm for tracking multi-objects with occlusion handling based on the multi-feature joint sparse reconstruction. The observation model based on sparse reconstruction automatically focuses on the visible parts of an occluded object by using the information in the trivial templates. The multi-object tracking is simplified into a joint Bayesian inference. The experimental results show the superiority of our algorithm over several state-of-the-art tracking algorithms.

  14. [CT measurement and clinical application of double-row suture anchor reconstruction for the treatment of Tossy type III acromioclavicular joint dislocation].

    PubMed

    Zhang, Chuan-Kai; Liu, Chen; Han, Bing; Feng, Hui; Chen, Qi-Zhong; Sunx, Sun Yi-Yan

    2017-04-25

    To study feasibility and reliability of reconstruction of the acromioclavicular ligament with double-row suture anchor for the treatment of acromioclavicular joint dislocation through coracoid coronal CT measurement, and to provide a new operation method for treating acromioclavicular joint dislocation. Total 60 healthy people received CT examination of shoulder joint, including 30 males and 30 females, ranging in age from 18 to 50 years old. The coronal width, thickness and 20 degree camber angle in the medial part of the toot of coronal were measured using CT scan. The results were applied to clinical treatment for 12 patients with acromioclavicular joint dislocation of Tossy III type. The width in the medial part of the root of the coracoid was(17.65±1.82) mm(left side) and (17.67±1.80) mm(right side) in males; (16.55±1.78) mm(left side) and (16.52±1.74) mm (right side) in females. The vertical thickness of the roots of the coracoid: (13.11±2.11) mm(left side) and (13.16±2.09) mm(right side) in males;(12.79±2.21) mm(left side) and (12.76±2.19) mm (right side) in females. The thickness of 20 degrees camber angle of the coracoid roots: (16.32±1.74) mm (left side) and (16.30±1.69) mm(right side) in males; (15.68±1.44) mm(left side) and (15.67±1.43) mm(right side) in females. Total 12 patients were treated with anchor nail with extraversion 20 degrees. The postoperative X-ray films showed bone anchors were located in the coracoid process, no bone splitting. Double-row suture anchor of 5 mm diameter nails can be placed into coracoid with extraversion 20 degrees, which is safety.

  15. Influence of age on the outcome of single stage reconstructive surgery for congenital dislocation of the hip joint.

    PubMed

    Bhatti, Anisuddin; Jamali, A R; Mehboob, Ghulam

    2009-01-01

    . On further analysis, a progressive deterioration of results with increasing age was observed, yet the results in those aged over 7 years were reasonably justified surgical correction of congenital dislocation of the hip joint. Majority of the complications were seen in children operated at the age of 4-5 years. There were 7 cases (14%) of redislocation/subluxation and 6 were in 3-7 years age group. There were 4 cases (8%) of the avascular necrosis of the femoral head. Three patients had residual coxa vara and 2 had significant limb shortening. Limb lengthening was done in these 2 cases. The final results displayed progressive deterioration of clinical, radiological and functional outcome measures with aging after single stage reconstructive surgery for the congenital dislocation of hip joint. However, despite this, the results in children over 7 years were also good/excellent in most of the cases justifying surgery.

  16. Upper-limb kinematic reconstruction during stroke robot-aided therapy.

    PubMed

    Papaleo, E; Zollo, L; Garcia-Aracil, N; Badesa, F J; Morales, R; Mazzoleni, S; Sterzi, S; Guglielmelli, E

    2015-09-01

    The paper proposes a novel method for an accurate and unobtrusive reconstruction of the upper-limb kinematics of stroke patients during robot-aided rehabilitation tasks with end-effector machines. The method is based on a robust analytic procedure for inverse kinematics that simply uses, in addition to hand pose data provided by the robot, upper arm acceleration measurements for computing a constraint on elbow position; it is exploited for task space augmentation. The proposed method can enable in-depth comprehension of planning strategy of stroke patients in the joint space and, consequently, allow developing therapies tailored for their residual motor capabilities. The experimental validation has a twofold purpose: (1) a comparative analysis with an optoelectronic motion capturing system is used to assess the method capability to reconstruct joint motion; (2) the application of the method to healthy and stroke subjects during circle-drawing tasks with InMotion2 robot is used to evaluate its efficacy in discriminating stroke from healthy behavior. The experimental results have shown that arm angles are reconstructed with a RMSE of 8.3 × 10(-3) rad. Moreover, the comparison between healthy and stroke subjects has revealed different features in the joint space in terms of mean values and standard deviations, which also allow assessing inter- and intra-subject variability. The findings of this study contribute to the investigation of motor performance in the joint space and Cartesian space of stroke patients undergoing robot-aided therapy, thus allowing: (1) evaluating the outcomes of the therapeutic approach, (2) re-planning the robotic treatment based on patient needs, and (3) understanding pathology-related motor strategies.

  17. Perspectives Do Matter: "Joint Screen", a Promising Methodology for Multimodal Interaction Analysis

    ERIC Educational Resources Information Center

    Arend, Béatrice; Sunnen, Patrick; Fixmer, Pierre; Sujbert, Monika

    2014-01-01

    This paper discusses theoretical and methodological issues arising from a video-based research design and the emergent tool "Joint Screen'"when grasping joint activity. We share our reflections regarding the combined reading of four synchronised camera perspectives combined in one screen. By these means we reconstruct and analyse…

  18. Optimizing Functional Outcomes in Mandibular Condyle Reconstruction With the Free Fibula Flap Using Computer-Aided Design and Manufacturing Technology.

    PubMed

    Lee, Z-Hye; Avraham, Tomer; Monaco, Casian; Patel, Ashish A; Hirsch, David L; Levine, Jamie P

    2018-05-01

    Mandibular defects involving the condyle represent a complex reconstructive challenge for restoring proper function of the temporomandibular joint (TMJ) because it requires precise bone graft alignment for full restoration of joint function. The use of computer-aided design and manufacturing (CAD/CAM) technology can aid in accurate reconstruction of mandibular condyle defects with a vascularized free fibula flap without the need for additional adjuncts. The purpose of this study was to analyze clinical and functional outcomes after reconstruction of mandibular condyle defects using only a free fibula graft with the help of virtual surgery techniques. A retrospective review was performed to identify all patients who underwent mandibular reconstruction with only a free fibula flap without any TMJ adjuncts after a total condylectomy. Three-dimensional modeling software was used to plan and execute reconstruction for all patients. From 2009 through 2014, 14 patients underwent reconstruction of mandibular defects involving the condyle with the aid of virtual surgery technology. The average age was 38.7 years (range, 11 to 77 yr). The average follow-up period was 2.6 years (range, 0.8 to 4.2 yr). Flap survival was 100% (N = 14). All patients reported improved facial symmetry, adequate jaw opening, and normal dental occlusion. In addition, they achieved good functional outcomes, including normal intelligible speech and the tolerance of a regular diet with solid foods. Maximal interincisal opening range for all patients was 25 to 38 mm with no lateral deviation or subjective joint pain. No patient had progressive joint hypomobility or condylar migration. One patient had ankylosis, which required release. TMJ reconstruction poses considerable challenges in bone graft alignment for full restoration of joint function. The use of CAD/CAM technology can aid in accurate reconstruction of mandibular condyle defects with a vascularized free fibula flap through precise

  19. Low Offset AC Correlator.

    DTIC Science & Technology

    This patent describes a low offset AC correlator avoids DC offset and low frequency noise by frequency operating the correlation signal so that low...noise, low level AC amplification can be substituted for DC amplification. Subsequently, the high level AC signal is demodulated to a DC level. (Author)

  20. [Secondary tendon reconstruction on the thumb].

    PubMed

    Bickert, B; Kremer, T; Kneser, U

    2016-12-01

    Closed tendon ruptures of the thumb that require secondary reconstruction can affect the extensor pollicis longus (EPL), extensor pollicis brevis (EPB) and flexor pollicis longus (FPL) tendons. Treatment of rupture of the EPB tendon consists of refixation to the bone and temporary transfixation of the joint. In the case of preexisting or posttraumatic arthrosis, definitive arthrodesis of the thumb is the best procedure. Closed ruptures of the EPL and FPL tendons at the wrist joint cannot be treated by direct tendon suture. Rupture of the EPL tendon occurs after distal radius fractures either due to protruding screws or following conservative treatment especially in undisplaced fractures. Transfer of the extensor indicis tendon to the distal EPL stump is a good option and free interposition of the palmaris longus tendon is a possible alternative. The tension should be adjusted to slight overcorrection, which can be checked intraoperatively by performing the tenodesis test. Closed FPL ruptures at the wrist typically occur 3-6 months after osteosynthesis of distal radius fractures with palmar plates and are mostly characterized by crepitation and pain lasting for several weeks. They can be prevented by premature plate removal, synovectomy and carpal tunnel release. For treatment of a ruptured FPL tendon in adult patients the options for tendon reconstruction should be weighed up against the less complicated tenodesis or arthrodesis of the thumb interphalangeal joint.

  1. Morphological analysis of acromion and hook plate for the fixation of acromioclavicular joint dislocation.

    PubMed

    Yoon, Jong Pil; Lee, Yeon Soo; Song, Geun Soo; Oh, Joo Han

    2017-03-01

    Acromioclavicular (AC) joint dislocation is a common sports injury. Hook plate fixation is currently widely used to treat this injury, as it can promote the natural healing of the ligament with good clinical outcomes. However, subacromial erosion and impingement are frequently observed post-operatively. It was hypothesized that the morphology and the contact characteristics between the hook portion and the acromion are the main causes of complications after hook plate fixation with the currently available commercial designs. Three-dimensional reconstructed models of the AC joint obtained from the computed tomographic scans of 23 male and 23 female patients (mean age, 61.1 ± 6.3 years) were evaluated, and multiple anatomical parameters were measured. For the subacromial positioning of the hook plate, an actual hook plate (Synthes Inc., West Chester, PA, USA) was scanned, and the contact between the hook plate and the acromion was estimated. The thicknesses of the acromion and distal clavicle were 9.7 ± 1.5 mm (10.7 mm in men; 8.6 mm in women) and 11.3 ± 1.6 mm (11.6 mm in men; 10.0 mm in women), respectively. The width of the acromion was 28.5 ± 3.6 mm. The mean inclination angle between the hook plate and the acromion was 29.3° ± 9.7° (27.9° in men; 30.6° in women). The hook plate made a point contact with the acromion at 9.2 ± 3.3 mm (31.5 %) from the lateral end of the acromion. The results revealed that the hook made a pinpoint contact with the undersurface of the acromion, and this might explain why complications commonly occur after hook plate fixation. The force concentration phenomenon associated with the hook plate of existing designs results from cases of morphological mismatch, such as excessive inclination and improper occupation of the subacromial space.

  2. US/Australia Collaborative Research Project on Corrosion Fatigue in D6AC Steel Joints

    DTIC Science & Technology

    1978-12-01

    Life of Exposure Groups at 80,000 psi Max Load Level (R=0.1) 77 10 Location of Observable Fatigue Cracks on Failed D6AC Steel Specimen Surfaces 78 11...ing the machining and assembly process. Such liquids might have a serious deleterious effect on the fatigue life of the aircraft. Further, there was...control tests were to provide a base for determining the various corrosion effects on fatigue life , and to deter- mine any differences in laboratory

  3. Alternating current (AC) iontophoretic transport across human epidermal membrane: effects of AC frequency and amplitude.

    PubMed

    Yan, Guang; Xu, Qingfang; Anissimov, Yuri G; Hao, Jinsong; Higuchi, William I; Li, S Kevin

    2008-03-01

    As a continuing effort to understand the mechanisms of alternating current (AC) transdermal iontophoresis and the iontophoretic transport pathways in the stratum corneum (SC), the objectives of the present study were to determine the interplay of AC frequency, AC voltage, and iontophoretic transport of ionic and neutral permeants across human epidermal membrane (HEM) and use AC as a means to characterize the transport pathways. Constant AC voltage iontophoresis experiments were conducted with HEM in 0.10 M tetraethyl ammonium pivalate (TEAP). AC frequencies ranging from 0.0001 to 25 Hz and AC applied voltages of 0.5 and 2.5 V were investigated. Tetraethyl ammonium (TEA) and arabinose (ARA) were the ionic and neutral model permeants, respectively. In data analysis, the logarithm of the permeability coefficients of HEM for the model permeants was plotted against the logarithm of the HEM electrical resistance for each AC condition. As expected, linear correlations between the logarithms of permeability coefficients and the logarithms of resistances of HEM were observed, and the permeability data were first normalized and then compared at the same HEM electrical resistance using these correlations. Transport enhancement of the ionic permeant was significantly larger than that of the neutral permeant during AC iontophoresis. The fluxes of the ionic permeant during AC iontophoresis of 2.5 V in the frequency range from 5 to 1,000 Hz were relatively constant and were approximately 4 times over those of passive transport. When the AC frequency decreased from 5 to 0.001 Hz at 2.5 V, flux enhancement increased to around 50 times over passive transport. While the AC frequency for achieving the full effect of iontophoretic enhancement at low AC frequency was lower than anticipated, the frequency for approaching passive diffusion transport at high frequency was higher than expected from the HEM morphology. These observations are consistent with a transport model of multiple

  4. Protection of the temporomandibular joint during syndromic neonatal mandibular distraction using condylar unloading.

    PubMed

    Fan, Kenneth; Andrews, Brian T; Liao, Eileen; Allam, Karam; Raposo Amaral, Cesar Augusto; Bradley, James P

    2012-05-01

    Neonatal distraction in severe micrognathia patients may alleviate the need for tracheostomy. The authors' objectives in evaluating syndromic neonatal distraction cases were to: (1) document preoperative temporomandibular joint pathology, (2) compare the incidence of postoperative temporomandibular joint ankylosis, and (3) determine whether "unloading" the condyle tended to prevent temporomandibular joint pathology. Syndromic versus nonsyndromic micrognathic (and normal) patient temporomandibular joint abnormalities were compared preoperatively based on computed tomography scans and incisor opening (n = 110). Patient temporomandibular joint outcomes after neonatal mandibular distraction were compared with regard to ankylosis (n = 59). Condylar-loaded versus condylar-unloaded (with class II intermaxillary elastics) temporomandibular joint outcomes were compared based on imaging and the need for joint reconstruction (n = 25). Preoperative abnormalities of neonatal temporomandibular joint pathology on computed tomography scans were not significant: syndromic, 15 percent; nonsyndromic, 5.9 percent; and normal joints, 4.2 percent. Syndromic patients had a significantly greater interincisor distance decrease postoperatively (48 percent; p < 0.05) and at 1-year follow-up (28 percent; p < 0.05) compared with nonsyndromic patients. Also, computed tomography scans revealed that 28 percent of syndromic patients developed temporomandibular joint abnormalities, whereas nonsyndromic patients were unchanged. Condylar-loaded patients had worse clinical outcomes compared with condylar-unloaded patients (80 percent versus 7 percent) and required temporomandibular joint reconstruction for bony ankylosis (40 percent versus 0 percent) after distraction. Neonatal syndromic, micrognathia patients have increased temporomandibular joint pathology preoperatively and bony ankylosis after distraction but are protected with partial unloading of the condyle during distraction. Risk, II

  5. Medial Patellofemoral Ligament Reconstruction Procedure Using a Suspensory Femoral Fixation System

    PubMed Central

    Nakagawa, Shuji; Arai, Yuji; Kan, Hiroyuki; Ueshima, Keiichiro; Ikoma, Kazuya; Terauchi, Ryu; Kubo, Toshikazu

    2013-01-01

    Recurrent patellar dislocation has recently been treated with anatomic medial patellofemoral ligament (MPFL) reconstruction using a semitendinosus muscle tendon. Although it is necessary to add tension to fix the tendon graft without loading excess stress on the patellofemoral joint, adjustment of the tension can be difficult. To resolve this problem, we developed an MPFL reconstruction procedure using the ToggleLoc Fixation Device (Biomet, Warsaw, IN), in which the semitendinosus muscle tendon is folded and used as a double-bundle tendon graft and 2 bone tunnels and 1 bone tunnel are made on the patellar and femoral sides, respectively. The patellar side of the tendon graft is fixed with an EndoButton (Smith & Nephew, London, England), and the femoral side is fixed with the ToggleLoc. Stepless adjustment of tension of the tendon graft is possible by reducing the size of the loop of the ToggleLoc hung onto the tendon graft. It may be useful to position the patella in the center of the femoral sulcus by confirming the patellofemoral joint fitting. Stability can be confirmed by loading lateral stress on the patella in the extended knee joint. This procedure is less invasive because opening of the lateral side of the femur is not necessary, and it may be useful for MPFL reconstruction. PMID:24892014

  6. Fires, A Joint Professional Bulletin for US Field & Air Defense Artillerymen. March-April 2008

    DTIC Science & Technology

    2008-04-01

    actions. However, if the effects synchronization division were not added to the lineup , just the teaming of joint fires division and IO division still...ADAFCO would be the liaison between the two Services who coordinates fires and facilitates track identification thus preventing fratricide. Joint...decisions to be made based on current air users versus planned control measures. Interoperability. Identification is a key feature that enables AC2 nodes

  7. Development of a 3D cell printed structure as an alternative to autologs cartilage for auricular reconstruction.

    PubMed

    Park, Ju Young; Choi, Yeong-Jin; Shim, Jin-Hyung; Park, Jeong Hun; Cho, Dong-Woo

    2017-07-01

    Surgical technique using autologs cartilage is considered as the best treatment for cartilage tissue reconstruction, although the burdens of donor site morbidity and surgical complications still remain. The purpose of this study is to apply three-dimensional (3D) cell printing to fabricate a tissue-engineered graft, and evaluate its effects on cartilage reconstruction. A multihead tissue/organ building system is used to print cell-printed scaffold (CPS), then assessed the effect of the CPS on cartilage regeneration in a rabbit ear. The cell viability and functionality of chondrocytes were significantly higher in CPS than in cell-seeded scaffold (CSS) and cell-seeded hybrid scaffold (CSHS) in vitro. CPS was then implanted into a rabbit ear that had an 8 mm-diameter cartilage defect; at 3 months after implantation the CPS had fostered complete cartilage regeneration whereas CSS and autologs cartilage (AC) fostered only incomplete healing. This result demonstrates that cell printing technology can provide an appropriate environment in which encapsulated chondrocytes can survive and differentiate into cartilage tissue in vivo. Moreover, the effects of CPS on cartilage regeneration were even better than those of AC. Therefore, we confirmed the feasibility of CPS as an alternative to AC for auricular reconstruction. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1016-1028, 2017. © 2016 Wiley Periodicals, Inc.

  8. Atomic modeling of cryo-electron microscopy reconstructions--joint refinement of model and imaging parameters.

    PubMed

    Chapman, Michael S; Trzynka, Andrew; Chapman, Brynmor K

    2013-04-01

    When refining the fit of component atomic structures into electron microscopic reconstructions, use of a resolution-dependent atomic density function makes it possible to jointly optimize the atomic model and imaging parameters of the microscope. Atomic density is calculated by one-dimensional Fourier transform of atomic form factors convoluted with a microscope envelope correction and a low-pass filter, allowing refinement of imaging parameters such as resolution, by optimizing the agreement of calculated and experimental maps. A similar approach allows refinement of atomic displacement parameters, providing indications of molecular flexibility even at low resolution. A modest improvement in atomic coordinates is possible following optimization of these additional parameters. Methods have been implemented in a Python program that can be used in stand-alone mode for rigid-group refinement, or embedded in other optimizers for flexible refinement with stereochemical restraints. The approach is demonstrated with refinements of virus and chaperonin structures at resolutions of 9 through 4.5 Å, representing regimes where rigid-group and fully flexible parameterizations are appropriate. Through comparisons to known crystal structures, flexible fitting by RSRef is shown to be an improvement relative to other methods and to generate models with all-atom rms accuracies of 1.5-2.5 Å at resolutions of 4.5-6 Å. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Joint quantum measurement using unbalanced array detection.

    PubMed

    Beck, M; Dorrer, C; Walmsley, I A

    2001-12-17

    We have measured the joint Q-function of a highly multimode field using unbalanced heterodyne detection with a charge-coupled device array detector. We use spectral interferometry between a weak signal field and a strong, 100 fs duration local oscillator pulse to reconstruct the joint quadrature amplitude statistics of about 25 temporal modes. By adjusting the time delay between the signal and local oscillator pulses we are able to shift all the classical noise to modes distinct from the signal. This obviates the need to use a balanced detector.

  10. Joint Force Quarterly. Number 13, Autumn 1996

    DTIC Science & Technology

    1996-10-01

    specifically ac- knowledges a 1986 study, “Ecuadorian- Peruvian Rivalry in the Upper Amazon,” as his source. That inaccurate account by William Krieg—based...joint Peruvian -Ecuadorian and U.S. records dating from 1942 to 1949 (released this year by Peru’s foreign ministry) clarify the historical account...despite the fact that Peruvian and Ecuadorian experts agreed in September 1948 to define the small stretch of the Cordillera del Cóndor which remains

  11. Joint Test Director. Joint Logistics Over-the-Shore II. Test and Evaluation. Analysis and Evaluation Report. JLOTS II Throughput Test.

    DTIC Science & Technology

    1985-08-01

    Class high - speed containerships and their subsequent conversion to a cargo configuration specifically designed for rapid load-offload of military unit...Rough Terrain Forklift SLWT Side-Loadable Warping Tug ST Short Ton STON Short Ton SUROB Surf Observations T-ACS Auxiliary Crane Ship T- AKR Auxiliary Cargo ...their delivery systems for container, breakbulk, and bulk liquid cargo , and to define the operating performance of the combined systems in a joint test

  12. Arthroscopic assisted tendon reconstruction for triangular fibrocartilage complex irreparable tears.

    PubMed

    Luchetti, R; Atzei, A

    2017-05-01

    We report our 11-year experience of performing arthroscopically assisted triangular fibrocartilage complex reconstruction in the treatment of chronic distal radio-ulnar joint instability resulting from irreparable triangular fibrocartilage complex injuries. Eleven patients were treated. Three skin incisions were made in order to create radial and ulna tunnels for passage of the tendon graft, which is used to reconstruct the dorsal and palmar radio-ulnar ligaments, under fluoroscopic and arthroscopic guidance. At a mean follow-up of 68 months all but one had a stable distal radio-ulnar joint. Pain and grip strength, Mayo wrist score, Disability of the Arm Hand and Shoulder and patient-rated wrist and hand evaluation scores improved. The ranges of forearm rotation remained largely unchanged. Complications included an early tendon graft tear, two late-onset graft ruptures, one ulna styloid fracture during surgery and persistent wrist discomfort during forearm rotation requiring tendon graft revision in one case. An arthroscopic assisted approach for triangular fibrocartilage complex reconstruction appears safe and produces comparable results with the open technique. IV.

  13. Knee kinematics and joint moments during gait following anterior cruciate ligament reconstruction: a systematic review and meta-analysis.

    PubMed

    Hart, Harvi F; Culvenor, Adam G; Collins, Natalie J; Ackland, David C; Cowan, Sallie M; Machotka, Zuzana; Crossley, Kay M

    2016-05-01

    Abnormal gait after anterior cruciate ligament reconstruction (ACLR) may contribute to development and/or progression of knee osteoarthritis. To conduct a systematic review and meta-analysis of knee kinematics and joint moments during walking after ACLR. We searched seven electronic databases and reference lists of relevant papers, for cross-sectional, human-based observational studies comparing knee joint kinematics and moments during level walking in individuals with ACLR, with the uninjured contralateral knee or healthy individuals as a control. Two independent reviewers appraised methodological quality (modified Downs and Black scale). Where possible, data were pooled by time post-ACLR (RevMan), otherwise narrative synthesis was undertaken. Thirty-four studies were included. Meta-analysis revealed significant sagittal plane deficits in ACLR knees. We found greater knee flexion angles (standardised mean difference: 1.06; 95% CI 0.39 to 1.74) and joint moments (1.61; 0.87 to 2.35) <6 months post-ACLR, compared to healthy controls. However, lower peak knee flexion angles were identified 1-3 years (-2.21; -3.16 to -1.26) and ≥3 years post-ACLR (-1.38, -2.14 to -0.62), and lower knee flexion moment 6-12 months post-ACLR (-0.76; -1.40 to -0.12). Pooled data provided strong evidence of no difference in peak knee adduction moment >3 years after ACLR (vs healthy controls) (0.09; -0.63 to 0.81). No transverse plane conclusions could be drawn. Sagittal plane biomechanics, rather than the knee adduction moment, appear to be more relevant post-ACLR. Better understanding of sagittal plane biomechanics is necessary for optimal post-operative recovery, and to potentially prevent early onset and progression of knee OA after ACLR. PROSPERO systematic review protocol registration number CRD4201400882 2. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. FLUIDIC AC AMPLIFIERS.

    DTIC Science & Technology

    Several fluidic tuned AC Amplifiers were designed and tested. Interstage tuning and feedback designs are considered. Good results were obtained...corresponding Q’s as high as 12. Element designs and test results of one, two, and three stage amplifiers are presented. AC Modulated Carrier Systems

  15. Effect of reconstruction of the anterior cruciate ligament on proprioception of the knee and the heel strike transient.

    PubMed

    Co, F H; Skinner, H B; Cannon, W D

    1993-09-01

    Abnormal proprioception of the knee joint has been documented after rupture of the anterior cruciate ligament (ACL) and may result in the loss of muscular reflexes. Excessive loading from the lack of muscular control may predispose the joint to osteoarthrosis. To investigate this problem, 10 patients were studied at an average of 31.6 months after ACL reconstruction. Three tests of joint proprioception and measurements of the vertical component of heel strike force during normal gait were used. A normal control group also was studied. For two of the proprioception tests (reproduction of passive motion and relative reproduction), there were no statistical differences among the uninjured (control) limbs, the normal contralateral limb of patients with a reconstructed ACL, and the extremity with a reconstructed ACL. In the third test (threshold of detection of motion), which previously has been shown to be adversely affected by ACL injury, the measurements for both extremities of patients with a reconstructed ACL were more accurate than those for the control group. The reconstructed extremity performed less accurately than the contralateral extremity (p < 0.05). The heel strike transient (vertical component of ground reaction force at heel strike) for uninjured and ACL-reconstructed limbs was not significantly different. In fact, the extremity with the reconstructed ACL had a lower transient than the uninjured extremity. Heel strike transients in patients with a reconstructed ACL were higher than those in the controls, but the differences were significant only when corrected for velocity of gait.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Fast GPU-based Monte Carlo code for SPECT/CT reconstructions generates improved 177Lu images.

    PubMed

    Rydén, T; Heydorn Lagerlöf, J; Hemmingsson, J; Marin, I; Svensson, J; Båth, M; Gjertsson, P; Bernhardt, P

    2018-01-04

    Full Monte Carlo (MC)-based SPECT reconstructions have a strong potential for correcting for image degrading factors, but the reconstruction times are long. The objective of this study was to develop a highly parallel Monte Carlo code for fast, ordered subset expectation maximum (OSEM) reconstructions of SPECT/CT images. The MC code was written in the Compute Unified Device Architecture language for a computer with four graphics processing units (GPUs) (GeForce GTX Titan X, Nvidia, USA). This enabled simulations of parallel photon emissions from the voxels matrix (128 3 or 256 3 ). Each computed tomography (CT) number was converted to attenuation coefficients for photo absorption, coherent scattering, and incoherent scattering. For photon scattering, the deflection angle was determined by the differential scattering cross sections. An angular response function was developed and used to model the accepted angles for photon interaction with the crystal, and a detector scattering kernel was used for modeling the photon scattering in the detector. Predefined energy and spatial resolution kernels for the crystal were used. The MC code was implemented in the OSEM reconstruction of clinical and phantom 177 Lu SPECT/CT images. The Jaszczak image quality phantom was used to evaluate the performance of the MC reconstruction in comparison with attenuated corrected (AC) OSEM reconstructions and attenuated corrected OSEM reconstructions with resolution recovery corrections (RRC). The performance of the MC code was 3200 million photons/s. The required number of photons emitted per voxel to obtain a sufficiently low noise level in the simulated image was 200 for a 128 3 voxel matrix. With this number of emitted photons/voxel, the MC-based OSEM reconstruction with ten subsets was performed within 20 s/iteration. The images converged after around six iterations. Therefore, the reconstruction time was around 3 min. The activity recovery for the spheres in the Jaszczak phantom was

  17. Development of a hardware-based AC microgrid for AC stability assessment

    NASA Astrophysics Data System (ADS)

    Swanson, Robert R.

    As more power electronic-based devices enable the development of high-bandwidth AC microgrids, the topic of microgrid power distribution stability has become of increased interest. Recently, researchers have proposed a relatively straightforward method to assess the stability of AC systems based upon the time-constants of sources, the net bus capacitance, and the rate limits of sources. In this research, a focus has been to develop a hardware test system to evaluate AC system stability. As a first step, a time domain model of a two converter microgrid was established in which a three phase inverter acts as a power source and an active rectifier serves as an adjustable constant power AC load. The constant power load can be utilized to create rapid power flow transients to the generating system. As a second step, the inverter and active rectifier were designed using a Smart Power Module IGBT for switching and an embedded microcontroller as a processor for algorithm implementation. The inverter and active rectifier were designed to operate simultaneously using a synchronization signal to ensure each respective local controller operates in a common reference frame. Finally, the physical system was created and initial testing performed to validate the hardware functionality as a variable amplitude and variable frequency AC system.

  18. Ligamentous and capsular injuries to the metacarpophalangeal joints of the hand.

    PubMed

    Shah, Smiresh Suresh; Techy, Fernando; Mejia, Alfonso; Gonzalez, Mark H

    2012-01-01

    The mechanism of dorsal dislocation of the metacarpophalangeal (MCP) joint is with forced hyperextension of the joint and the main structure injured is the volar plate. A simple dislocation can be reduced by closed means whereas a complex dislocation cannot. Care must be taken not to put traction across the joint, which may cause the volar plate to slip into the joint, converting a simple dislocation into a complex dislocation. Volar dislocations are rare and mainly treated nonoperatively. Sagittal band injuries can be treated with extension splinting or surgical management with direct repair or reconstruction. A locked MCP joint can usually be treated with closed manipulation. This article discusses these injuries and management options.

  19. Modeling Anisotropic Elastic Wave Propagation in Jointed Rock Masses

    NASA Astrophysics Data System (ADS)

    Hurley, R.; Vorobiev, O.; Ezzedine, S. M.; Antoun, T.

    2016-12-01

    We present a numerical approach for determining the anisotropic stiffness of materials with nonlinearly-compliant joints capable of sliding. The proposed method extends existing ones for upscaling the behavior of a medium with open cracks and inclusions to cases relevant to natural fractured and jointed rocks, where nonlinearly-compliant joints can undergo plastic slip. The method deviates from existing techniques by incorporating the friction and closure states of the joints, and recovers an anisotropic elastic form in the small-strain limit when joints are not sliding. We present the mathematical formulation of our method and use Representative Volume Element (RVE) simulations to evaluate its accuracy for joint sets with varying complexity. We then apply the formulation to determine anisotropic elastic constants of jointed granite found at the Nevada Nuclear Security Site (NNSS) where the Source Physics Experiments (SPE), a campaign of underground chemical explosions, are performed. Finally, we discuss the implementation of our numerical approach in a massively parallel Lagrangian code Geodyn-L and its use for studying wave propagation from underground explosions. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  20. A joint swarm intelligence algorithm for multi-user detection in MIMO-OFDM system

    NASA Astrophysics Data System (ADS)

    Hu, Fengye; Du, Dakun; Zhang, Peng; Wang, Zhijun

    2014-11-01

    In the multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) system, traditional multi-user detection (MUD) algorithms that usually used to suppress multiple access interference are difficult to balance system detection performance and the complexity of the algorithm. To solve this problem, this paper proposes a joint swarm intelligence algorithm called Ant Colony and Particle Swarm Optimisation (AC-PSO) by integrating particle swarm optimisation (PSO) and ant colony optimisation (ACO) algorithms. According to simulation results, it has been shown that, with low computational complexity, the MUD for the MIMO-OFDM system based on AC-PSO algorithm gains comparable MUD performance with maximum likelihood algorithm. Thus, the proposed AC-PSO algorithm provides a satisfactory trade-off between computational complexity and detection performance.

  1. Landing Mechanics During Side Hopping and Crossover Hopping Maneuvers in Noninjured Women and Women With Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Ortiz, Alexis; Olson, Sharon; Trudelle-Jackson, Elaine; Rosario, Martin; Venegas, Heidi L.

    2011-01-01

    Objective To compare, landing mechanics and electromyographic activity of the lower extremities during side hopping and crossover hopping maneuvers, in noninjured women and women with anterior cruciate ligament (ACL) reconstruction. Design A case-control study. Setting A 3-dimensional motion analysis laboratory. Participants Twenty-eight young women (range, 21–35 years) (15 control subjects and 13 subjects with ACL reconstruction). Patients and Methods All participants performed a side-to-side hopping task that consisted of hopping single-legged 10 times consecutively from side to side across 2 lines marked 30 cm apart on 2 individual force plates. The task was designated as a side hopping when the hop was to the opposite side of the stance leg and as crossover hopping when the hop was toward the side of the stance leg. Main Outcome Measurements Peak hip-/knee-joint angles; peak knee extension/abduction joint moments; electromyographic studies of the gluteus maximus, gluteus medius, rectus femoris, and hamstring muscles; and quadriceps/hamstring co-contraction ratio were compared between the groups by means of 2 × 2 multivariate analysis of variance tests (group × maneuver). Results Noninjured women and women with ACL reconstruction exhibited similar hip-and knee-joint angles during both types of hopping. Hip-joint angles were greater during the crossover hopping in both groups, and knee-joint angles did not differ between the groups or hops. Knee-joint moments demonstrated a significant group × maneuver interaction. Greater knee extension and valgus moments were noted in the control group during crossover hopping, and greater knee abduction moments were noted in the ACL group during side hopping. Electromyographic data revealed no statistically significantly differences between the groups. Conclusions Women with ACL reconstruction exhibited the restoration of functional biomechanical movements such as hip-/knee-joint angles and lower extremity neuromuscular

  2. Safety, tolerability, clinical, and joint structural outcomes of a single intra-articular injection of allogeneic mesenchymal precursor cells in patients following anterior cruciate ligament reconstruction: a controlled double-blind randomised trial.

    PubMed

    Wang, Yuanyuan; Shimmin, Andrew; Ghosh, Peter; Marks, Paul; Linklater, James; Connell, David; Hall, Stephen; Skerrett, Donna; Itescu, Silviu; Cicuttini, Flavia M

    2017-08-02

    Few clinical trials have investigated the safety and efficacy of mesenchymal stem cells for the management of post-traumatic osteoarthritis. The objectives of this pilot study were to determine the safety and tolerability and to explore the efficacy of a single intra-articular injection of allogeneic human mesenchymal precursor cells (MPCs) to improve clinical symptoms and retard joint structural deterioration over 24 months in patients following anterior cruciate ligament (ACL) reconstruction. In this phase Ib/IIa, double-blind, active comparator clinical study, 17 patients aged 18-40 years with unilateral ACL reconstruction were randomized (2:1) to receive either a single intra-articular injection of 75 million allogeneic MPCs suspended in hyaluronan (HA) (MPC + HA group) (n = 11) or HA alone (n = 6). Patients were monitored for adverse events. Immunogenicity was evaluated by anti-HLA panel reactive antibodies (PRA) against class I and II HLAs determined by flow cytometry. Pain, function, and quality of life were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and SF-36v2 scores. Joint space width was measured from radiographs, and tibial cartilage volume and bone area assessed from magnetic resonance imaging (MRI). Moderate arthralgia and swelling within 24 h following injection that subsided were observed in 4 out of 11 in the MPC + HA group and 0 out of 6 HA controls. No cell-related serious adverse effects were observed. Increases in class I PRA >10% were observed at week 4 in the MPC + HA group that decreased to baseline levels by week 104. Compared with the HA group, MPC + HA-treated patients showed greater improvements in KOOS pain, symptom, activities of daily living, and SF-36 bodily pain scores (p < 0.05). The MPC + HA group had reduced medial and lateral tibiofemoral joint space narrowing (p < 0.05), less tibial bone expansion (0.5% vs 4.0% over 26 weeks, p = 0.02), and a trend towards reduced tibial cartilage volume loss (0

  3. Performance trends of rehabilitated AC pavements

    DOT National Transportation Integrated Search

    2000-10-01

    The General Pavement Study (GPS) 6 experiment, "AC Overlay of AC Pavements," involves pavement test sections where an asphalt concrete (AC) overlay was placed on an existing AC pavement. This TechBrief summarizes the results of a study of the GPS-6 e...

  4. Joint Services Electronics Program.

    DTIC Science & Technology

    1985-03-31

    COJNRACT ON GRANT NuuSER(.j M. Tinkham N00014-84-K-0465 S. PeRFOR MING ORGANIZATION NAME AND ADORESS 𔃺. PROGRAM EL.,IT. P0OJECT. TASA Division of...2 7 R.W. Brockett DlAG29-83-K-0040 TW.osbr AFosR- 81-7401 R.W. Brockett -: DE -FGD2-84-EEw4O1 5B T.T. Wui sER xB-2-02144-l W. Paul JOINT SERVICES...0465, NSF DMR-81-08327 and SERI Subcontract XB-2-02144-1 of DOE Prime Contract DE -AC-02-83-CHI0093; Research Unit 2 (former #3). During this period we

  5. Accuracy assessment of 3D bone reconstructions using CT: an intro comparison.

    PubMed

    Lalone, Emily A; Willing, Ryan T; Shannon, Hannah L; King, Graham J W; Johnson, James A

    2015-08-01

    Computed tomography provides high contrast imaging of the joint anatomy and is used routinely to reconstruct 3D models of the osseous and cartilage geometry (CT arthrography) for use in the design of orthopedic implants, for computer assisted surgeries and computational dynamic and structural analysis. The objective of this study was to assess the accuracy of bone and cartilage surface model reconstructions by comparing reconstructed geometries with bone digitizations obtained using an optical tracking system. Bone surface digitizations obtained in this study determined the ground truth measure for the underlying geometry. We evaluated the use of a commercially available reconstruction technique using clinical CT scanning protocols using the elbow joint as an example of a surface with complex geometry. To assess the accuracies of the reconstructed models (8 fresh frozen cadaveric specimens) against the ground truth bony digitization-as defined by this study-proximity mapping was used to calculate residual error. The overall mean error was less than 0.4 mm in the cortical region and 0.3 mm in the subchondral region of the bone. Similarly creating 3D cartilage surface models from CT scans using air contrast had a mean error of less than 0.3 mm. Results from this study indicate that clinical CT scanning protocols and commonly used and commercially available reconstruction algorithms can create models which accurately represent the true geometry. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  6. Estimating BrAC from transdermal alcohol concentration data using the BrAC estimator software program.

    PubMed

    Luczak, Susan E; Rosen, I Gary

    2014-08-01

    Transdermal alcohol sensor (TAS) devices have the potential to allow researchers and clinicians to unobtrusively collect naturalistic drinking data for weeks at a time, but the transdermal alcohol concentration (TAC) data these devices produce do not consistently correspond with breath alcohol concentration (BrAC) data. We present and test the BrAC Estimator software, a program designed to produce individualized estimates of BrAC from TAC data by fitting mathematical models to a specific person wearing a specific TAS device. Two TAS devices were worn simultaneously by 1 participant for 18 days. The trial began with a laboratory alcohol session to calibrate the model and was followed by a field trial with 10 drinking episodes. Model parameter estimates and fit indices were compared across drinking episodes to examine the calibration phase of the software. Software-generated estimates of peak BrAC, time of peak BrAC, and area under the BrAC curve were compared with breath analyzer data to examine the estimation phase of the software. In this single-subject design with breath analyzer peak BrAC scores ranging from 0.013 to 0.057, the software created consistent models for the 2 TAS devices, despite differences in raw TAC data, and was able to compensate for the attenuation of peak BrAC and latency of the time of peak BrAC that are typically observed in TAC data. This software program represents an important initial step for making it possible for non mathematician researchers and clinicians to obtain estimates of BrAC from TAC data in naturalistic drinking environments. Future research with more participants and greater variation in alcohol consumption levels and patterns, as well as examination of gain scheduling calibration procedures and nonlinear models of diffusion, will help to determine how precise these software models can become. Copyright © 2014 by the Research Society on Alcoholism.

  7. Abnormal landing strategies after ACL reconstruction.

    PubMed

    Gokeler, A; Hof, A L; Arnold, M P; Dijkstra, P U; Postema, K; Otten, E

    2010-02-01

    The objective was to analyze muscle activity and movement patterns during landing of a single leg hop for distance after anterior cruciate ligament (ACL) reconstruction. Nine (six males, three females) ACL-reconstructed patients 6 months after surgery and 11 (eight males, three females) healthy control subjects performed the hop task. Electromyographic signals from lower limb muscles were analyzed to determine onset time before landing. Biomechanical data were collected using an Optotrak Motion Analysis System and force plate. Matlab was used to calculate kinetics and joint kinematics. Side-to-side differences in ACL-reconstructed patients and healthy subjects as well as differences between the patients and control group were analyzed. In ACL-reconstructed limbs, significantly earlier onset times were found for all muscles, except vastus medialis, compared with the uninvolved side. The involved limbs had significantly reduced knee flexion during the take-off and increased plantarflexion at initial contact. The knee extension moment was significantly lower in the involved limb. In the control group, significantly earlier onset times were found for the semitendinosus, vastus lateralis and medial gastrocnemius of the non-dominant side compared with the dominant side. Muscle onset times are earlier and movement patterns are altered in the involved limb 6 months after ACL reconstruction.

  8. Reconstruction of the two-dimensional gravitational potential of galaxy clusters from X-ray and Sunyaev-Zel'dovich measurements

    NASA Astrophysics Data System (ADS)

    Tchernin, C.; Bartelmann, M.; Huber, K.; Dekel, A.; Hurier, G.; Majer, C. L.; Meyer, S.; Zinger, E.; Eckert, D.; Meneghetti, M.; Merten, J.

    2018-06-01

    Context. The mass of galaxy clusters is not a direct observable, nonetheless it is commonly used to probe cosmological models. Based on the combination of all main cluster observables, that is, the X-ray emission, the thermal Sunyaev-Zel'dovich (SZ) signal, the velocity dispersion of the cluster galaxies, and gravitational lensing, the gravitational potential of galaxy clusters can be jointly reconstructed. Aims: We derive the two main ingredients required for this joint reconstruction: the potentials individually reconstructed from the observables and their covariance matrices, which act as a weight in the joint reconstruction. We show here the method to derive these quantities. The result of the joint reconstruction applied to a real cluster will be discussed in a forthcoming paper. Methods: We apply the Richardson-Lucy deprojection algorithm to data on a two-dimensional (2D) grid. We first test the 2D deprojection algorithm on a β-profile. Assuming hydrostatic equilibrium, we further reconstruct the gravitational potential of a simulated galaxy cluster based on synthetic SZ and X-ray data. We then reconstruct the projected gravitational potential of the massive and dynamically active cluster Abell 2142, based on the X-ray observations collected with XMM-Newton and the SZ observations from the Planck satellite. Finally, we compute the covariance matrix of the projected reconstructed potential of the cluster Abell 2142 based on the X-ray measurements collected with XMM-Newton. Results: The gravitational potentials of the simulated cluster recovered from synthetic X-ray and SZ data are consistent, even though the potential reconstructed from X-rays shows larger deviations from the true potential. Regarding Abell 2142, the projected gravitational cluster potentials recovered from SZ and X-ray data reproduce well the projected potential inferred from gravitational-lensing observations. We also observe that the covariance matrix of the potential for Abell 2142

  9. Lack of genotoxicity in vivo for food color additive Allura Red AC.

    PubMed

    Bastaki, Maria; Farrell, Thomas; Bhusari, Sachin; Pant, Kamala; Kulkarni, Rohan

    2017-07-01

    Allura Red AC is an approved food color additive internationally with INS number 129, in the United States as food color subject to batch certification "Food, Drug, and Cosmetic" (FD&C) Red No. 40, and in Europe as food color additive with E number 129. In their evaluation of the color (2013), the European Food Safety Authority (EFSA) expressed concerns of potential genotoxicity, based primarily on one genotoxicity study that was not conducted according to Guidelines. The present in vivo genotoxicity study was conducted according to OECD Guidelines in response to EFSA's request for additional data. The animal species and strain, and the tissues examined were selected specifically to address the previously reported findings. The results show clear absence of genotoxic activity for Allura Red AC, in the bone marrow micronucleus assay and the Comet assay in the liver, stomach, and colon. These data addressed EFSA's concerns for genotoxicity. The Joint WHO/FAO Committee on Food Additives (JECFA) (2016) also reviewed the study and concluded that there is no genotoxicity concern for Allura Red AC. Negative findings in parallel genotoxicity studies on Tartrazine and Ponceau 4R (published separately) are consistent with lack of genotoxicity for azo dyes used as food colors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. AC/RC Force Integration

    DTIC Science & Technology

    1991-05-01

    ib qeocie. Thki document may not be rdeaed for open publicado. untit hu been deared by die appropriate military seavice or a veunent agency. AC /RC...A N/A N/A 11. TITLE (Include Security Classification) AC /RC Force Structure Integraticn 12. PERSONAL AUTHOR(S) Russell A. Eggers 13a. TYPE OF REPORT... AC ) and Reserve Components (RC) Force Integration is critical in today’s Total Army. The Army of soldiers, Active and Reserve, exists to play a key

  11. [COMPARISON OF EFFECTIVENESS BETWEEN TWO OPERATIVE TECHNIQUES OF CORACOCLAVICULAR LIGAMENT RECONSTRUCTION FOR TREATMENT OF Tossy TYPE III ACROMIOCLAVICULAR JOINT DISLOCATION].

    PubMed

    Tang, Hongwei; Gao, Sheng; Yin, Yong; Li, Yunfei; Han, Qingtian; Li, Huizhang

    2015-11-01

    To evaluate and compare the effectiveness of double Endobutton technique and suture anchor combined Endobutton plate in the treatment of Tossy type III acromioclavicular joint dislocation. Between May 2010 and March 2014, a retrospective study was preformed on 56 patients with Tossy type III acromioclavicular joint dislocation. The coracoclavicular ligament was reconstructed with double Endobutton technique in 31 cases (Endobutton group), and with suture anchor combined Endobutton plate in 25 cases (Anchor group). There was no significant difference in age, gender, injury causes, injury side, associated injury, medical comorbidities, and disease duration between 2 groups (P>0.05). The operation time, medical device expenses, postoperative complications, preoperative and postoperative Constant-Murley scores, and postoperative Karlsson grading of the injured shoulder were compared between 2 groups. The average operation time in Endobutton group was significantly greater than that in Anchor group (t = 4.285, P = 0.000); there was no significant difference in the medical device expenses between 2 groups (t = 1.555, P = 0.126). Primary healing of incision was obtained in all patients of 2 groups; no early complications of infection and skin necrosis occurred. All patients were followed up 15.6 months on average (range, 11-35 months). During follow-up, some loss of reduction and ectopic ossification in the coracoclavicular gap were observed in 1 case and 6 cases of Endobutton group, respectively. No recurrence of acromioclavicular joint dislocation, implant fixation loosening and broken, and secondary fractures occurred in the other patients. There was significant difference in the incidence of postoperative complications between 2 groups (P = 0.013). Constant-Murley scores of the injured shoulder significantly increased at 9 months after operation when compared with preoperative values in 2 groups (P < 0.05), but no significant difference was observed between 2 groups

  12. Characterizing fiber-reinforced composite structures using AC-impedance spectroscopy (AC-IS)

    NASA Astrophysics Data System (ADS)

    Woo, Leta Y.

    Property enhancement in composites depends largely on the reinforcement. For fiber-reinforced composites, the distribution of fibers is crucial in determining the electrical and mechanical performance. Image analysis methods for characterization can be time-consuming and/or destructive. This work explores the capability of AC-impedance spectroscopy (AC-IS), an electrical measurement technique, to serve as a rapid, non-destructive tool for characterizing composite microstructure. The composite requirements include a filler that is electrically conducting or semi-conducting with higher conductivity than the matrix, and a high-impedance interface or coating between the filler and the matrix. To establish an AC-IS characterization method, cement-matrix composites with steel reinforcement were employed as both a technologically important and a model system to investigate how fibers affect the electrical response. Beginning with spherical particulates and then fibers, composites were examined using composite theory and an "intrinsic conductivity" approach. The intrinsic conductivity approach applies to composites with low volume fractions of fibers (i.e., in the dilute regime) and relates how the composite conductivity varies relative to the matrix as a function of volume fraction. A universal equivalent circuit model was created to understand the AC-IS response of composites based on the geometry and volume fraction of the filler. Deviation from predicted behavior was assessed using a developed f-function, which quantifies how fibers contribute to the overall electrical response of the composite. Using the f-function, an AC-IS method for investigating fiber dispersion was established to characterize alignment, settling/segregation, and aggregation. Alignment was investigated using measurements made in three directions. A point-probe technique characterized settling and/or large-scale inhomogeneous mixing in samples. Aggregation was quantified using a "dispersion factor

  13. MR Guided PET Image Reconstruction

    PubMed Central

    Bai, Bing; Li, Quanzheng; Leahy, Richard M.

    2013-01-01

    The resolution of PET images is limited by the physics of positron-electron annihilation and instrumentation for photon coincidence detection. Model based methods that incorporate accurate physical and statistical models have produced significant improvements in reconstructed image quality when compared to filtered backprojection reconstruction methods. However, it has often been suggested that by incorporating anatomical information, the resolution and noise properties of PET images could be improved, leading to better quantitation or lesion detection. With the recent development of combined MR-PET scanners, it is possible to collect intrinsically co-registered MR images. It is therefore now possible to routinely make use of anatomical information in PET reconstruction, provided appropriate methods are available. In this paper we review research efforts over the past 20 years to develop these methods. We discuss approaches based on the use of both Markov random field priors and joint information or entropy measures. The general framework for these methods is described and their performance and longer term potential and limitations discussed. PMID:23178087

  14. Absorption and Attenuation Coefficients Using the WET Labs ac-s in the Mid-Atlantic Bight: Field Measurements and Data Analysis

    NASA Technical Reports Server (NTRS)

    Ohi, Nobuaki; Makinen, Carla P.; Mitchell, Richard; Moisan, Tiffany A.

    2008-01-01

    Ocean color algorithms are based on the parameterization of apparent optical properties as a function of inherent optical properties. WET Labs underwater absorption and attenuation meters (ac-9 and ac-s) measure both the spectral beam attenuation [c (lambda)] and absorption coefficient [a (lambda)]. The ac-s reports in a continuous range of 390-750 nm with a band pass of 4 nm, totaling approximately 83 distinct wavelengths, while the ac-9 reports at 9 wavelengths. We performed the ac-s field measurements at nine stations in the Mid-Atlantic Bight from water calibrations to data analysis. Onboard the ship, the ac-s was calibrated daily using Milli Q-water. Corrections for the in situ temperature and salinity effects on optical properties of water were applied. Corrections for incomplete recovery of the scattered light in the ac-s absorption tube were performed. The fine scale of spectral and vertical distributions of c (lambda) and a (lambda) were described from the ac-s. The significant relationships between a (674) and that of spectrophotometric analysis and chlorophyll a concentration of discrete water samples were observed.

  15. Anatomical reconstruction of the lateral ligaments of the ankle with a gracilis autograft: a new technique using an interference fit anchoring system.

    PubMed

    Takao, Masato; Oae, Kazunori; Uchio, Yuji; Ochi, Mitsuo; Yamamoto, Haruyasu

    2005-06-01

    Few anatomical and minor invasive procedures have been reported for surgical reconstruction of the lateral ligaments to treat lateral instability of the ankle. Furthermore, there are no standards according to which ligaments should be reconstructed. A new technique for anatomically reconstructing the lateral ligaments of the ankle using an interference fit anchoring system and determining which ligaments need to be reconstructed according to the results of standard stress radiography of the talocrural and subtalar joints will be effective for treating lateral instability of the ankle. Case series; level of evidence, 4. Twenty-one patients with lateral instability of the ankle underwent surgery using the proposed interference fit anchoring system. Standard stress radiographs of the subtalar joint were performed, and if the talocalcaneal angle was less than 10 degrees , only the anterior talofibular ligament was reconstructed; if there was a 10 degrees or greater opening of the talocalcaneal angle, both the anterior talofibular ligament and the calcaneofibular ligament were reconstructed. In the 17 patients who received only the anterior talofibular ligament reconstruction, the mean talar tilt angle on standard stress radiography of the talocrural joint was 14.5 degrees +/- 1.7 degrees before surgery and 2.6 degrees +/- 0.8 degrees 2 years after surgery (P < .0001). For the 4 patients who had both the anterior talofibular ligament and calcaneofibular ligament reconstructed, the mean talar tilt angle was 16.5 degrees +/- 1.5 degrees before surgery and 3.0 degrees +/- 0.5 degrees 2 years after surgery (P = .0015). The overall mean talocalcaneal angle on standard stress radiography of the subtalar joint was 11.3 degrees +/- 1.4 degrees before surgery and 3.5 degrees +/- 0.8 degrees 2 years after surgery (P = .0060). The proposed system has several advantages, including anatomical reconstruction with normal stability and range of motion restored, the need for only a

  16. Prospective analysis of temporomandibular joint reconstruction in ankylosis with sternoclavicular graft and buccal fat pad lining.

    PubMed

    Singh, Virendra; Dhingra, Rahul; Bhagol, Amrish

    2012-04-01

    To evaluate the feasibility of sternoclavicular graft (SCG) as an adaptive center along with buccal fat pad (BFP) lining for temporomandibular joint (TMJ) reconstruction in TMJ ankylosis. A prospective, preliminary, short-term study with only 6 months' follow-up was performed in 10 patients with TMJ ankylosis. All patients had complete osseous ankylosis, and the mean duration of ankylosis was 6.4 years (range, 3 to 13 years). Interpositional arthroplasty with SCG along with BFP lining was done in all cases. Postoperative clinical and radiographic follow-up was performed for 6 to 9 months. Maximum interincisal opening at 6 months' follow-up was 35.6 ± 4.97 mm (range, 31 to 45 mm). Similarly, protrusive movement at follow-up of 6 months was 2.7 ± 1.25 mm (range, 1.5 to 5.5 mm), whereas laterotrusive movement was 4.1 ± 1.98 mm (range, 1.5 to 7.0 mm) toward the affected side and 2.4 ± 0.99 mm (range, 1 to 4.0 mm) toward the normal side. After 3 months, 9 of 10 patients had no pain on function, and all the patients were relieved of pain at the end of 6 months. On radiographic follow-up at 9 months, there was noticeably significant adaptation and remodeling of SCG as observed on panoramic radiography and computed tomography scan. In all the patients there was some degree of mandibular deviation toward the operated side, although the occlusion was satisfactory and they were pleased with the outcome. On the basis of the findings of this study, we conclude that after release of TMJ ankylosis, reconstruction with SCG combined with interposition of BFP lining followed by vigorous physiotherapy is a successful strategy for the management of TMJ ankylosis with short-term follow-up of 6 months. Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Cartilage repair and joint preservation: medical and surgical treatment options.

    PubMed

    Madry, Henning; Grün, Ulrich Wolfgang; Knutsen, Gunnar

    2011-10-01

    Articular cartilage defects are most often caused by trauma and osteoarthritis and less commonly by metabolic disorders of the subchondral bone, such as osteonecrosis and osteochondritis dissecans. Such defects do not heal spontaneously in adults and can lead to secondary osteoarthritis. Medications are indicated for symptomatic relief. Slow-acting drugs in osteoarthritis (SADOA), such as glucosamine and chondroitin, are thought to prevent cartilage degeneration. Reconstructive surgical treatment strategies aim to form a repair tissue or to unload compartments of the joint with articular cartilage damage. In this article, we selectively review the pertinent literature, focusing on original publications of the past 5 years and older standard texts. Particular attention is paid to guidelines and clinical studies with a high level of evidence, along with review articles, clinical trials, and book chapters. There have been only a few randomized trials of medical versus surgical treatments. Pharmacological therapies are now available that are intended to treat the cartilage defect per se, rather than the associated symptoms, yet none of them has yet been shown to slow or reverse the progression of cartilage destruction. Surgical débridement of cartilage does not prevent the progression of osteoarthritis and is thus not recommended as the sole treatment. Marrow-stimulating procedures and osteochondral grafts are indicated for small focal articular cartilage defects, while autologous chondrocyte implantationis mainly indicated for larger cartilage defects. These surgical reconstructive techniques play a lesser role in the treatment of osteoarthritis. Osteotomy near the knee joint is indicated for axial realignment when unilateral osteoarthritis of the knee causes axis deviation. Surgical reconstructive techniques can improve joint function and thereby postpone the need for replacement of the articular surface with an artificial joint.

  18. Adaptations in single-leg hop biomechanics following anterior cruciate ligament reconstruction.

    PubMed

    Orishimo, Karl F; Kremenic, Ian J; Mullaney, Michael J; McHugh, Malachy P; Nicholas, Stephen J

    2010-11-01

    When a patient performs a clinically normal hop test based on distance, it cannot be assumed that the biomechanics are similar between limbs. The objective was to compare takeoff and landing biomechanics between legs in patients who have undergone anterior cruciate ligament reconstruction. Kinematics and ground reaction forces were recorded as 13 patients performed the single-leg hop on each leg. Distance hopped, joint range of motion, peak joint kinetics and the peak total extensor moment were compared between legs during both takeoff and landing. Average hop distance ratio (involved/noninvolved) was 93 ± 4%. Compared to the noninvolved side, knee motion during takeoff on the involved side was significantly reduced (P = 0.008). Peak moments and powers on the involved side were lower at the knee and higher at the ankle and hip compared with the noninvolved side (Side by Joint P = 0.011; P = 0.003, respectively). The peak total extensor moment was not different between legs (P = 0.305) despite a decrease in knee moment and increases in ankle and hip moments (Side by Joint P = 0.015). During landing, knee motion was reduced (P = 0.043), and peak power absorbed was decreased at the knee and hip and increased at the ankle on the involved side compared to the noninvolved side (P = 0.003). The compensations by other joints may indicate protective adaptations to avoid overloading the reconstructed knee.

  19. The ACS statistical analyzer

    DOT National Transportation Integrated Search

    2010-03-01

    This document provides guidance for using the ACS Statistical Analyzer. It is an Excel-based template for users of estimates from the American Community Survey (ACS) to assess the precision of individual estimates and to compare pairs of estimates fo...

  20. Alloplastic total temporomandibular joint replacements: do they perform like natural joints? Prospective cohort study with a historical control.

    PubMed

    Wojczyńska, A; Leiggener, C S; Bredell, M; Ettlin, D A; Erni, S; Gallo, L M; Colombo, V

    2016-10-01

    The aim of this study was to qualitatively and quantitatively describe the biomechanics of existing total alloplastic reconstructions of temporomandibular joints (TMJ). Fifteen patients with unilateral or bilateral TMJ total joint replacements and 15 healthy controls were evaluated via dynamic stereometry technology. This non-invasive method combines three-dimensional imaging of the subject's anatomy with jaw tracking. It provides an insight into the patient's jaw joint movements in real time and provides a quantitative evaluation. The patients were also evaluated clinically for jaw opening, protrusive and laterotrusive movements, pain, interference with eating, and satisfaction with the joint replacements. The qualitative assessment revealed that condyles of bilateral total joint replacements displayed similar basic motion patterns to those of unilateral prostheses. Quantitatively, mandibular movements of artificial joints during opening, protrusion, and laterotrusion were all significantly shorter than those of controls. A significantly restricted mandibular range of motion in replaced joints was also observed clinically. Fifty-three percent of patients suffered from chronic pain at rest and 67% reported reduced chewing function. Nonetheless, patients declared a high level of satisfaction with the replacement. This study shows that in order to gain a comprehensive understanding of complex therapeutic measures, a multidisciplinary approach is needed. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  1. Real Time Computation of Kinetic Constraints to Support Equilibrium Reconstruction

    NASA Astrophysics Data System (ADS)

    Eggert, W. J.; Kolemen, E.; Eldon, D.

    2016-10-01

    A new method for quickly and automatically applying kinetic constraints to EFIT equilibrium reconstructions using readily available data is presented. The ultimate goal is to produce kinetic equilibrium reconstructions in real time and use them to constrain the DCON stability code as part of a disruption avoidance scheme. A first effort presented here replaces CPU-time expensive modules, such as the fast ion pressure profile calculation, with a simplified model. We show with a DIII-D database analysis that we can achieve reasonable predictions for selected applications by modeling the fast ion pressure profile and determining the fit parameters as functions of easily measured quantities including neutron rate and electron temperature on axis. Secondly, we present a strategy for treating Thomson scattering and Charge Exchange Recombination data to automatically form constraints for a kinetic equilibrium reconstruction, a process that historically was performed by hand. Work supported by US DOE DE-AC02-09CH11466 and DE-FC02-04ER54698.

  2. The AC photovoltaic module is here!

    NASA Astrophysics Data System (ADS)

    Strong, Steven J.; Wohlgemuth, John H.; Wills, Robert H.

    1997-02-01

    This paper describes the design, development, and performance results of a large-area photovoltaic module whose electrical output is ac power suitable for direct connection to the utility grid. The large-area ac PV module features a dedicated, integrally mounted, high-efficiency dc-to-ac power inverter with a nominal output of 250 watts (STC) at 120 Vac, 60 H, that is fully compatible with utility power. The module's output is connected directly to the building's conventional ac distribution system without need for any dc wiring, string combiners, dc ground-fault protection or additional power-conditioning equipment. With its advantages, the ac photovoltaic module promises to become a universal building block for use in all utility-interactive PV systems. This paper discusses AC Module design aspects and utility interface issues (including islanding).

  3. 78 FR 78964 - Subcommittee for Dose Reconstruction Reviews (SDRR), Advisory Board on Radiation and Worker...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Subcommittee for Dose Reconstruction Reviews (SDRR), Advisory Board on Radiation and Worker Health (ABRWH or the Advisory Board), National Institute for Occupational Safety and Health (NIOSH) In accordance with section 10(a)(2) of the Federal Advisory Committee Ac...

  4. Salvage reconstruction of failed interposition arthroplasty at the base of the thumb.

    PubMed

    Braun, Richard M; Rechnic, Mark; Shah, Kalpit N

    2012-12-01

    We present an operative procedure designed to revise a failed arthroplasty at the base of the thumb. This report describes a reliable operation that corrects residual instability and malignment which results in thumbs that are weak and painful despite a previous procedure. The operation has also been used as a primary procedure for arthritis of the trapeziometacarpal joint where instability and subluxation was a major component of the problem requiring joint reconstruction. The unique features of this procedure include a reinforced double-thickness tendon graft, a unique tendon anchor, and a fascia lata allograft spacer. Significant functional improvement is anticipated when joint reconstruction provides increased proximal stability. Pinch and grip measurements improve. Pain scores also diminish after the operation. Hand function and patient satisfaction can be substantially improved with revision arthroplasty when the initial operation has failed to provide a thumb that is mobile, stable, and pain free. The technical features of the procedure address reduction of malignment, restoring of anatomic balance, and secure fixation of the proximal apex of the thumb metacarpal which restores thumb reduction position and digital balance.

  5. A Transplant-Specific Quality Initiative-Introducing TransQIP: A Joint Effort of the ASTS and ACS.

    PubMed

    Parekh, J; Ko, C; Lappin, J; Greenstein, S; Hirose, R

    2017-07-01

    In an attempt to improve surgical quality in the field of transplantation, the American College of Surgeons (ACS) and American Society of Transplant Surgeons have initiated a national quality improvement program in transplantation. This transplant-specific quality improvement program, called TransQIP, has been built from the ground up by transplant surgeons and captures detailed information on donor and recipient factors as well as transplant-specific outcomes. It is built upon the existing ACS/National Surgical Quality Improvement Program infrastructure and is designed to capture 100% of liver and kidney transplants performed at participating sites. TransQIP has completed its alpha pilot and will embark upon its beta phase at approximately 30 centers in the spring of 2017. Going forward, we anticipate TransQIP will help satisfy Centers for Medicare and Medicaid Services requirements for a quality improvement program, surgeon requirements for maintenance of certification, and qualify as a clinical practice improvement activity under the Merit-Based Incentive Payment System. Most importantly, we believe TransQIP will provide insight into surgical outcomes in transplantation that will allow the field to provide better care to our patients. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

  6. Imaging diagnosis--temporomandibular joint dysplasia in a Basset Hound.

    PubMed

    Lerer, Assaf; Chalmers, Heather J; Moens, Noel M M; Mackenzie, Shawn D; Kry, Kristin

    2014-01-01

    A 5-month-old intact male Basset Hound presented for evaluation of pain and crepitation during manipulation of the temporomandibular joint, worse on the right side. A computed tomography (CT) scan of the head was performed. The CT images demonstrated the osseous features of temporomandibular joint dysplasia and facilitated a 3D reconstruction, which allowed better visualization of the dysplastic features. The patient responded to conservative management with a tape muzzle with no recurrence reported by the owner 6 months after presentation. © 2013 American College of Veterinary Radiology.

  7. Impact of joint statistical dual-energy CT reconstruction of proton stopping power images: Comparison to image- and sinogram-domain material decomposition approaches.

    PubMed

    Zhang, Shuangyue; Han, Dong; Politte, David G; Williamson, Jeffrey F; O'Sullivan, Joseph A

    2018-05-01

    The purpose of this study was to assess the performance of a novel dual-energy CT (DECT) approach for proton stopping power ratio (SPR) mapping that integrates image reconstruction and material characterization using a joint statistical image reconstruction (JSIR) method based on a linear basis vector model (BVM). A systematic comparison between the JSIR-BVM method and previously described DECT image- and sinogram-domain decomposition approaches is also carried out on synthetic data. The JSIR-BVM method was implemented to estimate the electron densities and mean excitation energies (I-values) required by the Bethe equation for SPR mapping. In addition, image- and sinogram-domain DECT methods based on three available SPR models including BVM were implemented for comparison. The intrinsic SPR modeling accuracy of the three models was first validated. Synthetic DECT transmission sinograms of two 330 mm diameter phantoms each containing 17 soft and bony tissues (for a total of 34) of known composition were then generated with spectra of 90 and 140 kVp. The estimation accuracy of the reconstructed SPR images were evaluated for the seven investigated methods. The impact of phantom size and insert location on SPR estimation accuracy was also investigated. All three selected DECT-SPR models predict the SPR of all tissue types with less than 0.2% RMS errors under idealized conditions with no reconstruction uncertainties. When applied to synthetic sinograms, the JSIR-BVM method achieves the best performance with mean and RMS-average errors of less than 0.05% and 0.3%, respectively, for all noise levels, while the image- and sinogram-domain decomposition methods show increasing mean and RMS-average errors with increasing noise level. The JSIR-BVM method also reduces statistical SPR variation by sixfold compared to other methods. A 25% phantom diameter change causes up to 4% SPR differences for the image-domain decomposition approach, while the JSIR-BVM method and sinogram

  8. Slow-onset and fast-onset symptom presentations in acute coronary syndrome (ACS): new perspectives on prehospital delay in patients with ACS.

    PubMed

    O'Donnell, Sharon; McKee, Gabrielle; Mooney, Mary; O'Brien, Frances; Moser, Debra K

    2014-04-01

    Patient decision delay is the main reason why many patients fail to receive timely medical intervention for symptoms of acute coronary syndrome (ACS). This study examines the validity of slow-onset and fast-onset ACS presentations and their influence on ACS prehospital delay times. A fast-onset ACS presentation is characterized by sudden, continuous, and severe chest pain, and slow-onset ACS pertains to all other ACS presentations. Baseline data pertaining to medical profiles, prehospital delay times, and ACS symptoms were recorded for all ACS patients who participated in a large multisite randomized control trial (RCT) in Dublin, Ireland. Patients were interviewed 2-4 days after their ACS event, and data were gathered using the ACS Response to Symptom Index. Only baseline data from the RCT, N = 893 patients, were analyzed. A total of 65% (n = 577) of patients experienced slow-onset ACS presentation, whereas 35% (n = 316) experienced fast-onset ACS. Patients who experienced slow-onset ACS were significantly more likely to have longer prehospital delays than patients with fast-onset ACS (3.5 h vs. 2.0 h, respectively, t = -5.63, df 890, p < 0.001). A multivariate analysis of delay revealed that, in the presence of other known delay factors, the only independent predictors of delay were slow-onset and fast-onset ACS (β = -.096, p < 0.002) and other factors associated with patient behavior. Slow-onset ACS and fast-onset ACS presentations are associated with distinct behavioral patterns that significantly influence prehospital time frames. As such, slow-onset ACS and fast-onset ACS are legitimate ACS presentation phenomena that should be seriously considered when examining the factors associated with prehospital delay. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Knee Contact Force Asymmetries in Patients Who Failed Return-to-Sport Readiness Criteria 6 Months After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Gardinier, Emily S.; Di Stasi, Stephanie; Manal, Kurt; Buchanan, Thomas S.; Snyder-Mackler, Lynn

    2015-01-01

    Background After anterior cruciate ligament (ACL) injury, contact forces are decreased in the injured knee when compared with the uninjured knee. The persistence of contact force asymmetries after ACL reconstruction may increase the risk of reinjury and may play an important role in the development of knee osteoarthritis in these patients. Functional performance may also be useful in identifying patients who demonstrate potentially harmful joint contact force asymmetries after ACL reconstruction. Hypothesis Knee joint contact force asymmetries would be present during gait after ACL reconstruction, and performance on a specific set of validated return-to-sport (RTS) readiness criteria would discriminate between those who demonstrated contact force asymmetries and those who did not. Study Design Descriptive laboratory study. Methods A total of 29 patients with ACL ruptures participated in gait analysis and RTS readiness testing 6 months after reconstruction. Muscle and joint contact forces were estimated using an electromyography (EMG)–driven musculoskeletal model of the knee. The magnitude of typical limb asymmetry in uninjured controls was used to define limits of meaningful limb asymmetry in patients after ACL reconstruction. The RTS testing included isometric quadriceps strength testing, 4 unilateral hop tests, and 2 self-report questionnaires. Paired t tests were used to assess limb symmetry for peak medial and tibiofemoral contact forces in all patients, and a mixed-design analysis of variance was used to analyze the effect of passing or failing RTS testing on contact force asymmetry. Results Among all patients, neither statistically significant nor meaningful contact force asymmetries were identified. However, patients who failed RTS testing exhibited meaningful contact force asymmetries, with tibiofemoral contact force being significantly lower for the involved knee. Conversely, patients who passed RTS testing exhibited neither significant nor meaningful

  10. Fusion in posttraumatic foot and ankle reconstruction.

    PubMed

    Thordarson, David B

    2004-01-01

    Despite appropriate acute treatment, many foot and ankle injuries result in posttraumatic arthritis. Arthrodesis remains the mainstay of treatment of end-stage arthritis of the foot and ankle. An understanding of the biomechanics of the foot and ankle, particularly which joints are most responsible for optimal function of the foot, can help guide reconstructive efforts. A careful history and physical examination, appropriate radiographs, and, when necessary, differential selective anesthetic blocks help limit fusion to only those joints that are causing pain. Compression fixation, when possible, remains the treatment of choice. When bone defects are present, however, neutralization fixation may be necessary to prevent a secondary deformity that could result from impaction into a bone defect.

  11. Transient AC voltage related phenomena for HVDC schemes connected to weak AC systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pilotto, L.A.S.; Szechtman, M.; Hammad, A.E.

    1992-07-01

    In this paper a didactic explanation of voltage stability associated phenomena at HVDC terminals is presented. Conditions leading to ac voltage collapse problems are identified. A mechanism that excites control-induced voltage oscillations is shown. The voltage stability factor is used for obtaining the maximum power limits of ac/dc systems operating with different control strategies. Correlation to Pd {times} Id curves is given. Solutions for eliminating the risks of voltage collapse and for avoiding control-induced oscillations are discussed. The results are supported by detailed digital simulations of a weak ac/dc system using EMTP.

  12. Analysis of change in gait in the ovine stifle: normal, injured, and anterior cruciate ligament reconstructed.

    PubMed

    Heard, B J; Beveridge, J E; Atarod, M; O'Brien, E J; Rolian, C; Frank, C B; Hart, D A; Shrive, N G

    2017-05-23

    Many patients who undergo anterior cruciate ligament (ACL) reconstructive surgery develop post-traumatic osteoarthritis (PTOA). ACL reconstructive surgery may not fully restore pre-injury joint biomechanics, thereby resulting in further joint damage and contributing to the development of PTOA. In an ovine model of idealized ACL reconstruction (ACL-R), it has been shown that signs of PTOA develop within surgical joints by 20 weeks post-surgery. The aim of the present study was to investigate whether altered kinematics contribute to early PTOA development within ACL-R joints of the ovine injury model by comparing the gait of these surgical animals to the gait of a stable normal control group, and an unstable injury group in which the ACL and medial collateral ligament (MCL) had been transected. Fifteen skeletally mature female sheep were allocated evenly into 3 treatment groups: normal control, ACL-R, and ACL/MCL Tx (each group n = 5). Each animal's gait was recorded at baseline, 4 weeks post injury, and 20 weeks post injury. Principal component analysis (PCA) was used to identify the kinematic patterns that may be discriminant between treatment groups. Results from previous studies were referenced to present the amount of gross PTOA-like changes that occurred in the joints. ACL-R and ACL/MCL transected (Tx) animals developed a similar amount of early PTOA-like changes within the surgical joints, but differed significantly in the amount of kinematic change present at 20 weeks post-surgery. We showed that the stifle joint kinematics of ACL/MCL Tx differed significantly from those of CTRL and the majority of ACL-R animals, while no significant differences in joint kinematic changes were found between ACL-R and CTRL animals. These results suggest that the early PTOA-like changes reported in the ACL-R model cannot be attributed exclusively to post-surgical kinematic changes, and therefore biologic components in the post-injury environment must be contributing

  13. Effects of Single-Bundle and Double-Bundle ACL Reconstruction on Tibiofemoral Compressive Stresses and Joint Kinematics During Simulated Squatting

    PubMed Central

    Mulcahey, Mary K.; Monchik, Keith O.; Yongpravat, Charlie; Badger, Gary J.; Fadale, Paul D.; Hulstyn, Michael J.; Fleming, Braden C.

    2011-01-01

    The purpose of this study was to compare tibiofemoral (TF) kinematics and TF compressive stresses between single bundle- (SB-) and double bundle-ACL reconstruction (DB-ACLR) during simulated squatting. Twelve matched pairs of fresh frozen cadaver knees were utilized. A simulated squat through 100° of knee flexion was performed in the ACL-intact joint. The ACL was transected and SB- and DB-ACLR procedures were performed in one knee of each pair. The squat was repeated. Knee kinematics were measured using a motion tracking system and the TF compressive forces were measured using thin film pressure sensors. The posterior shifts of the tibia for SB- and DB-ACLR knees were significantly greater than the ACL-intact condition for knee flexion angles 0° to 40° (p<.05). However, there was no difference between the SB- and DB-ACLR knees at any flexion angle (0° to 100°; p=.37). SB- and DB-ACLR knees had greater IE rotation than intact knees from 90° through 50° of flexion (p<.05), but not between 40° and full extension. There was no difference between SB- and DB-ACLR knees (p=.68). The TF compressive stresses of the DB-ACLR were significantly lower than intact for all angles except 10° (p=.06), whereas SB-ACLR knees did not differ from intact at flexion angles between 30° and 50° (p>.32). There were no significant differences between the two reconstruction conditions (p=.74). This study showed that there was no difference in the TF kinematics or compressive stresses between SB- and DB-ACLR, and only minor differences when compared to the intact state. PMID:21696962

  14. Arthroscopic Coracoclavicular Ligament Reconstruction Using a Synthetic Polycaprolactone-Based Polyurethane Urea Tendon Graft: A Report of 5 Cases.

    PubMed

    Ranne, Juha O; Kainonen, Terho U; Lempainen, Lasse L; Kosola, Jussi A; Kajander, Sami A; Niemi, Pekka T

    2018-06-01

    Several techniques have been introduced to treat acromioclavicular (AC) separation using the semitendinosus tendon as a graft for coracoclavicular (CC) ligament reconstruction. However, the tendon may have been used previously or the patient may not want it harvested. Hence, synthetic tendon transfers have become increasingly popular. Five patients with chronic AC separations were treated. A synthetic polyurethane urea tendon graft (Artelon Tissue Reinforcement [ATR]) was chosen for its ability to partially transform into connective tissue. The patient follow-up period lasted 45 to 60 months. The mean preoperative Constant Score increased from 64.8 to 100 postoperatively. The mean preoperative Simple Shoulder Test increased from 7.2 to 12 postoperatively. The mean postoperative increase of the CC distance was 1.5 mm. The mean expansion of the clavicular drill hole from the original was 2.1 mm. According to the postoperative magnetic resonance imaging, the grafts had healed well and the cross-sections of the grafts were up to 10.5 mm between the coracoid and the clavicle. The synthetic ATR tendon strip was a practical method for reconstructing a torn CC ligament complex. The ATR graft appears promising for future CC ligament reconstructions.

  15. Ankle fusion for definitive management of non-reconstructable pilon fractures.

    PubMed

    Bozic, Vladimir; Thordarson, David B; Hertz, Jennifer

    2008-09-01

    Highly comminuted pilon fractures, especially with a compromised soft tissue envelope, present a challenging treatment scenario. This study presents our results for patients managed with ankle fusion rather than ORIF. Fourteen patients with ankle joint incongruence after non-reconstructable tibia pilon fractures were treated with primary tibiotalar arthrodesis using a fixed-angle cannulated blade plate. Delayed metaphyseal unions due to bone defects were treated concurrently. The subtalar joint was preserved in all cases. Metaphyseal healing and stable arthrodesis was obtained in each case. There was one case of blade plate breakage in a patient who still achieved successful arthrodesis without reoperation. Union was achieved at an average of 15 weeks. No secondary procedures were required to obtain union. All 14 patients were ambulatory at last followup. Average followup was 39 weeks. Primary ankle arthrodesis can be achieved using a cannulated blade plate to address a non-reconstructable articular surface and metaphyseal bone defects in complex tibia pilon fractures.

  16. Microfabricated AC impedance sensor

    DOEpatents

    Krulevitch, Peter; Ackler, Harold D.; Becker, Frederick; Boser, Bernhard E.; Eldredge, Adam B.; Fuller, Christopher K.; Gascoyne, Peter R. C.; Hamilton, Julie K.; Swierkowski, Stefan P.; Wang, Xiao-Bo

    2002-01-01

    A microfabricated instrument for detecting and identifying cells and other particles based on alternating current (AC) impedance measurements. The microfabricated AC impedance sensor includes two critical elements: 1) a microfluidic chip, preferably of glass substrates, having at least one microchannel therein and with electrodes patterned on both substrates, and 2) electrical circuits that connect to the electrodes on the microfluidic chip and detect signals associated with particles traveling down the microchannels. These circuits enable multiple AC impedance measurements of individual particles at high throughput rates with sufficient resolution to identify different particle and cell types as appropriate for environmental detection and clinical diagnostic applications.

  17. Mechanics and materials in middle ear reconstruction.

    PubMed

    Lesser, T H; Williams, K R; Blayney, A W

    1991-02-01

    The normal anatomy and physiology of the middle ear is not reproduced in ossiculoplasty and an artificial mechanism for the transmission of sound results. This is true for all types of graft, be they of natural or man-made material. There are, therefore, 2 areas for consideration when looking at the problems encountered in such reconstructions: first, the materials' biocompatability and, secondly, the mechanical effects of the positioning of the graft in the reconstructed ossicular chain. The present work examines these mechanical effects using the finite element method to determine stress and displacement levels in the reconstructed ossicular chain. It is found that the stress levels at the implant-stapedial joint increases as the implant is gradually moved down the malleus. In contrast there is thought to be an increase in sound transmission as the implant is moved down the malleus. Changes in rigidity and hardness of the implant appear to make only modest stress attenuations at the implant-stapes interface.

  18. Model-Based Estimation of Ankle Joint Stiffness

    PubMed Central

    Misgeld, Berno J. E.; Zhang, Tony; Lüken, Markus J.; Leonhardt, Steffen

    2017-01-01

    We address the estimation of biomechanical parameters with wearable measurement technologies. In particular, we focus on the estimation of sagittal plane ankle joint stiffness in dorsiflexion/plantar flexion. For this estimation, a novel nonlinear biomechanical model of the lower leg was formulated that is driven by electromyographic signals. The model incorporates a two-dimensional kinematic description in the sagittal plane for the calculation of muscle lever arms and torques. To reduce estimation errors due to model uncertainties, a filtering algorithm is necessary that employs segmental orientation sensor measurements. Because of the model’s inherent nonlinearities and nonsmooth dynamics, a square-root cubature Kalman filter was developed. The performance of the novel estimation approach was evaluated in silico and in an experimental procedure. The experimental study was conducted with body-worn sensors and a test-bench that was specifically designed to obtain reference angle and torque measurements for a single joint. Results show that the filter is able to reconstruct joint angle positions, velocities and torque, as well as, joint stiffness during experimental test bench movements. PMID:28353683

  19. Imaging osteoarthritis in the knee joints using x-ray guided diffuse optical tomography

    NASA Astrophysics Data System (ADS)

    Zhang, Qizhi; Yuan, Zhen; Sobel, Eric S.; Jiang, Huabei

    2010-02-01

    In our previous studies, near-infrared (NIR) diffuse optical tomography (DOT) had been successfully applied to imaging osteoarthritis (OA) in the finger joints where significant difference in optical properties of the joint tissues was evident between healthy and OA finger joints. Here we report for the first time that large joints such as the knee can also be optically imaged especially when DOT is combined with x-ray tomosynthesis where the 3D image of the bones from x-ray is incorporated into the DOT reconstruction as spatial a priori structural information. This study demonstrates that NIR light can image large joints such as the knee in addition to finger joints, which will drastically broaden the clinical utility of our x-ray guided DOT technique for OA diagnosis.

  20. High voltage AC/AC electrochemical capacitor operating at low temperature in salt aqueous electrolyte

    NASA Astrophysics Data System (ADS)

    Abbas, Qamar; Béguin, François

    2016-06-01

    We demonstrate that an activated carbon (AC)-based electrochemical capacitor implementing aqueous lithium sulfate electrolyte in 7:3 vol:vol water/methanol mixture can operate down to -40 °C with good electrochemical performance. Three-electrode cell investigations show that the faradaic contributions related with hydrogen chemisorption in the negative AC electrode are thermodynamically unfavored at -40 °C, enabling the system to work as a typical electrical double-layer (EDL) capacitor. After prolonged floating of the AC/AC capacitor at 1.6 V and -40°C, the capacitance, equivalent series resistance and efficiency remain constant, demonstrating the absence of ageing related with side redox reactions at this temperature. Interestingly, when temperature is increased back to 24 °C, the redox behavior due to hydrogen storage reappears and the system behaves as a freshly prepared one.

  1. [Repair and reconstruction for severe fracture and dislocation of ankle joint].

    PubMed

    Yin, Qingwei; Jiang, Yi; Xiao, Lianping; Li, Xiaodong; Fu, Jiaxin; Tian, Yonggang; Han, Liqiang; Liu, Zhi

    2008-06-01

    To summarize the technique and effect of the therapy for severe fracture and dislocation of ankle joint by operation. From March 2003 to February 2006, 76 cases were treated with primary open restoration and internal fixation for dislocated ankle joint fracture, with 47 males and 29 females, with the average age of 36.4 years (ranging from 18 years to 65 years). According to AO criterion, these fresh fractures were classified into 13 cases for type C3-1, 45 cases for type C3-2 and 18 cases for type C3-3. Based on the Gustilo-Anderson standard, 23 open fractures were classified into 17 cases for type II and 6 cases for type III A. The operation was delayed from 1 hours to 24 hours after the injury. All incisions healed at the first stage except 4 cases which delayed union because of simple infection by revision with ointment. A total of 72 cases were followed up, with the average time of 18.5 months (from 12 months to 35 months). The time of bone union was from 12 weeks to 24 weeks. The screws of fixation for lower tibia-fibula joint were found to be ruptured in 2 cases when further consultation was performed in the 16th and 20th week after the operation, respectively, and were broken within 1 year after the operation. These screws were taken out 12 weeks postoperative in 28 cases, while the whole internal fixations of the rest cases were taken out 1 year after the operation. The postoperative function of malleolus extended from 21.7 degrees to 26.8 degrees and flection from 38.5 degrees to 44.7 degrees. Assessed by the American Orthopaedic Foot and Ankle Society Clinical Rating Scales, 23 cases were excellent, 36 good, 13 fair, and the choiceness rate reached 81.94%. These procedures, together with reduction by twist after hospital, open and internal fixation in time, and parenchyma managed with internal fixation, are important to attain satisfactory effect for the treatment of severe fracture and dislocation of ankle joint.

  2. High susceptibility and low resistance allele frequency of Chrysodeixis includens (Lepidoptera: Noctuidae) field populations to Cry1Ac in Brazil.

    PubMed

    Yano, Silvia Ac; Specht, Alexandre; Moscardi, Flávio; Carvalho, Renato A; Dourado, Patrick M; Martinelli, Samuel; Head, Graham P; Sosa-Gómez, Daniel R

    2016-08-01

    The soybean looper (SBL), Chrysodeixis includens (Walker), is one of the most important soybean pests in Brazil. MON 87701 × MON 89788 soybean expressing Cry1Ac has been recently deployed in Brazil, providing high levels of control against the primary lepidopteran pests. To support insect resistance management (IRM) programmes, the baseline susceptibility of SBL to Cry1Ac was assessed, and the resistance allele frequency was estimated on the basis of an F2 screen. The toxicity (LC50 ) of Cry1Ac ranged from 0.39 to 2.01 µg mL(-1) diet among all SBL field populations collected from crop seasons 2008/09 to 2012/13, which indicated approximately fivefold variation. Cry1Ac diagnostic concentrations of 5.6 and 18 µg mL(-1) diet were established for monitoring purposes, and no shift in mortality was observed. A total of 626 F2 family lines derived from SBL collected from locations across Brazil during crop season 2014/15 were screened for the presence of Cry1Ac resistance alleles. None of the 626 families survived on MON 87701 × MON 89788 soybean leaf tissue (joint frequency 0.0004). SBL showed high susceptibility and low resistance allele frequency to Cry1Ac across the main soybean-producing regions in Brazil. These findings meet important criteria for effective IRM strategy. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  3. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and remove...

  4. Quantitative three-dimensional photoacoustic tomography of the finger joints: an in vivo study

    NASA Astrophysics Data System (ADS)

    Sun, Yao; Sobel, Eric; Jiang, Huabei

    2009-11-01

    We present for the first time in vivo full three-dimensional (3-D) photoacoustic tomography (PAT) of the distal interphalangeal joint in a human subject. Both absorbed energy density and absorption coefficient images of the joint are quantitatively obtained using our finite-element-based photoacoustic image reconstruction algorithm coupled with the photon diffusion equation. The results show that major anatomical features in the joint along with the side arteries can be imaged with a 1-MHz transducer in a spherical scanning geometry. In addition, the cartilages associated with the joint can be quantitatively differentiated from the phalanx. This in vivo study suggests that the 3-D PAT method described has the potential to be used for early diagnosis of joint diseases such as osteoarthritis and rheumatoid arthritis.

  5. Photometric Lunar Surface Reconstruction

    NASA Technical Reports Server (NTRS)

    Nefian, Ara V.; Alexandrov, Oleg; Morattlo, Zachary; Kim, Taemin; Beyer, Ross A.

    2013-01-01

    Accurate photometric reconstruction of the Lunar surface is important in the context of upcoming NASA robotic missions to the Moon and in giving a more accurate understanding of the Lunar soil composition. This paper describes a novel approach for joint estimation of Lunar albedo, camera exposure time, and photometric parameters that utilizes an accurate Lunar-Lambertian reflectance model and previously derived Lunar topography of the area visualized during the Apollo missions. The method introduced here is used in creating the largest Lunar albedo map (16% of the Lunar surface) at the resolution of 10 meters/pixel.

  6. [Classification and Treatment of Sacroiliac Joint Dislocation].

    PubMed

    Tan, Zhen; Huang, Zhong; Li, Liang; Meng, Wei-Kun; Liu, Lei; Zhang, Hui; Wang, Guang-Lin; Huang, Fu-Guo

    2017-09-01

    To develop a renewed classification and treatment regimen for sacroiliac joint dislocation. According to the direction of dislocation of sacroiliac joint,combined iliac,sacral fractures,and fracture morphology,sacroiliac joint dislocation was classified into 4 types. Type Ⅰ (sacroiliac anterior dislocation): main fracture fragments of posterior iliac wing dislocated in front of sacroiliac joint. Type Ⅱ (sacroiliac posterior dislocation): main fracture fragments of posterior iliac wing dislocated in posterior of sacroiliac joint. Type Ⅲ (Crescent fracturedislocation of the sacroiliac joint): upward dislocation of posterior iliac wing with oblique fracture through posterior iliac wing. Type ⅢA: a large crescent fragment and dislocation comprises no more than onethird of sacroiliac joint,which is typically inferior. Type ⅢB: intermediatesize crescent fragment and dislocation comprises between one and twothirds of joint. Type ⅢC: a small crescent fragment where dislocation comprises most,but not the entire joint. Different treatment regimens were selected for different types of fractures. Treatment for type Ⅰ sacroiliac joint dislocation: anterior iliac fossa approach pry stripping reset; sacroiliac joint fixed with sacroiliac screw through percutaneous. Treatment for type Ⅱ sacroiliac joint dislocation: posterior sacroiliac joint posterior approach; sacroiliac joint fixed with sacroiliac screw under computer guidance. Treatment for type ⅢA and ⅢB sacroiliac joint dislocation: posterior sacroiliac joint approach; sacroiliac joint fixed with reconstruction plate. Treatment for type ⅢC sacroiliac joint dislocation: sacroiliac joint closed reduction; sacroiliac joint fixed with sacroiliac screw through percutaneous. Treatment for type Ⅳ sacroiliac joint dislocation: posterior approach; sacroiliac joint fixed with spinal pelvic fixation. Results of 24 to 72 months patient follow-up (mean 34.5 months): 100% survival,100% wound healing,and 100

  7. Population Coding of Forelimb Joint Kinematics by Peripheral Afferents in Monkeys

    PubMed Central

    Umeda, Tatsuya; Seki, Kazuhiko; Sato, Masa-aki; Nishimura, Yukio; Kawato, Mitsuo; Isa, Tadashi

    2012-01-01

    Various peripheral receptors provide information concerning position and movement to the central nervous system to achieve complex and dexterous movements of forelimbs in primates. The response properties of single afferent receptors to movements at a single joint have been examined in detail, but the population coding of peripheral afferents remains poorly defined. In this study, we obtained multichannel recordings from dorsal root ganglion (DRG) neurons in cervical segments of monkeys. We applied the sparse linear regression (SLiR) algorithm to the recordings, which selects useful input signals to reconstruct movement kinematics. Multichannel recordings of peripheral afferents were performed by inserting multi-electrode arrays into the DRGs of lower cervical segments in two anesthetized monkeys. A total of 112 and 92 units were responsive to the passive joint movements or the skin stimulation with a painting brush in Monkey 1 and Monkey 2, respectively. Using the SLiR algorithm, we reconstructed the temporal changes of joint angle, angular velocity, and acceleration at the elbow, wrist, and finger joints from temporal firing patterns of the DRG neurons. By automatically selecting a subset of recorded units, the SLiR achieved superior generalization performance compared with a regularized linear regression algorithm. The SLiR selected not only putative muscle units that were responsive to only the passive movements, but also a number of putative cutaneous units responsive to the skin stimulation. These results suggested that an ensemble of peripheral primary afferents that contains both putative muscle and cutaneous units encode forelimb joint kinematics of non-human primates. PMID:23112841

  8. Supervised de novo reconstruction of metabolic pathways from metabolome-scale compound sets

    PubMed Central

    Kotera, Masaaki; Tabei, Yasuo; Yamanishi, Yoshihiro; Tokimatsu, Toshiaki; Goto, Susumu

    2013-01-01

    Motivation: The metabolic pathway is an important biochemical reaction network involving enzymatic reactions among chemical compounds. However, it is assumed that a large number of metabolic pathways remain unknown, and many reactions are still missing even in known pathways. Therefore, the most important challenge in metabolomics is the automated de novo reconstruction of metabolic pathways, which includes the elucidation of previously unknown reactions to bridge the metabolic gaps. Results: In this article, we develop a novel method to reconstruct metabolic pathways from a large compound set in the reaction-filling framework. We define feature vectors representing the chemical transformation patterns of compound–compound pairs in enzymatic reactions using chemical fingerprints. We apply a sparsity-induced classifier to learn what we refer to as ‘enzymatic-reaction likeness’, i.e. whether compound pairs are possibly converted to each other by enzymatic reactions. The originality of our method lies in the search for potential reactions among many compounds at a time, in the extraction of reaction-related chemical transformation patterns and in the large-scale applicability owing to the computational efficiency. In the results, we demonstrate the usefulness of our proposed method on the de novo reconstruction of 134 metabolic pathways in Kyoto Encyclopedia of Genes and Genomes (KEGG). Our comprehensively predicted reaction networks of 15 698 compounds enable us to suggest many potential pathways and to increase research productivity in metabolomics. Availability: Softwares are available on request. Supplementary material are available at http://web.kuicr.kyoto-u.ac.jp/supp/kot/ismb2013/. Contact: goto@kuicr.kyoto-u.ac.jp PMID:23812977

  9. Virtual trajectories, joint stiffness, and changes in the limb natural frequency during single-joint oscillatory movements.

    PubMed

    Latash, M L

    1992-07-01

    In the framework of the equilibrium-point hypothesis, virtual trajectories and patterns of joint stiffness were reconstructed during voluntary single-joint oscillatory movements in the elbow joint at a variety of frequencies and against two inertial loads. At low frequencies, virtual trajectories were in-phase with the actual joint trajectories. Joint stiffness changed at a doubled frequency. An increase in movement frequency and/or inertial load led to an increase in the difference between the peaks of the actual and virtual trajectories and in both peak and averaged values of joint stiffness. At a certain, critical frequency, virtual trajectory was nearly flat. Further increase in movement frequency led to a 180 degree phase shift between the actual and virtual trajectories. The assessed values of the natural frequency of the system "limb + manipulandum" were close to the critical frequencies for both low and high inertial loads. Peak levels and integrals of the electromyograms of two flexor and two extensor muscles changed monotonically with movement frequency without any special behavior at the critical frequencies. Nearly flat virtual trajectories at the natural frequency make physical sense as hypothetical control signals, unlike the electromyographic recordings, since a system at its natural frequency requires minimal central interference. Modulation of joint stiffness is assumed to be an important adaptive mechanism attenuating difference between the system's natural frequency and desired movement frequency. Virtual trajectory is considered a behavioral observable. Phase transitions between the virtual and actual trajectories are illustrations of behavioral discontinuities introduced by slow changes in a higher level control parameter, movement frequency. Relative phase shift between these two trajectories may be considered an order parameter.

  10. Predicting fundamental frequency from mel-frequency cepstral coefficients to enable speech reconstruction.

    PubMed

    Shao, Xu; Milner, Ben

    2005-08-01

    This work proposes a method to reconstruct an acoustic speech signal solely from a stream of mel-frequency cepstral coefficients (MFCCs) as may be encountered in a distributed speech recognition (DSR) system. Previous methods for speech reconstruction have required, in addition to the MFCC vectors, fundamental frequency and voicing components. In this work the voicing classification and fundamental frequency are predicted from the MFCC vectors themselves using two maximum a posteriori (MAP) methods. The first method enables fundamental frequency prediction by modeling the joint density of MFCCs and fundamental frequency using a single Gaussian mixture model (GMM). The second scheme uses a set of hidden Markov models (HMMs) to link together a set of state-dependent GMMs, which enables a more localized modeling of the joint density of MFCCs and fundamental frequency. Experimental results on speaker-independent male and female speech show that accurate voicing classification and fundamental frequency prediction is attained when compared to hand-corrected reference fundamental frequency measurements. The use of the predicted fundamental frequency and voicing for speech reconstruction is shown to give very similar speech quality to that obtained using the reference fundamental frequency and voicing.

  11. The application of 3D printed surgical guides in resection and reconstruction of malignant bone tumor.

    PubMed

    Wang, Fengping; Zhu, Jun; Peng, Xuejun; Su, Jing

    2017-10-01

    The clinical value of 3D printed surgical guides in resection and reconstruction of malignant bone tumor around the knee joint were studied. For this purpose, a sample of 66 patients from October 2013 to October 2015 were randomly selected and further divided into control group and observation group, each group consisted of 33 cases. The control group was treated by conventional tumor resection whereas, in the observation group, the tumor was resected with 3D printed surgical guide. However, reconstruction of tumor-type hinge prosthesis was performed in both groups and then the clinical effect was compared. Results show that there was no significant difference in the operation time between the two groups (p>0.05). However, the blood loss, resection length and complication rate were found significantly lower in the observation group than in the control group (p<0.05). The rate of negative margin and the recurrence rate in the 12-month follow-up (p>0.05) between two groups were statistically the same (p>0.05), whereas the Musculoskeletal Tumor Society (MSTS) score of the knee joint in the observation group was significantly better than that of the control group (p<0.05) after 1, 3, 6 and 12 months of the operation. Consequently, the 3D printed surgical guides can significantly improve the postoperative joint function after resection and reconstruction of malignant bone tumor around the knee joint and can reduce the incidence of complications.

  12. The AC 2000.2 Catalogue

    NASA Astrophysics Data System (ADS)

    Urban, S. E.; Corbin, T. E.; Wycoff, G. L.; Makarov, V. V.; Høg, E.; Fabricius, C.

    2001-12-01

    For over 100 years, the international project known as the Astrographic Catalogue -- which involved 20 observatories tasked to photograph the sky -- has held an unfulfilled promised of yielding a wealth of astrometric information. This promise was not realized due to the inadequate reductions of the project's plates. However, in 1997 the U.S. Naval Observatory (USNO) completed the reductions of the 22,660 plates. That catalogue, named the AC 2000, contained positions and magnitudes for 4.6 million stars down to about v magnitude 12.5. Due to the early epochs of the data -- averaging 1907 -- and the positional accuracies -- between 150 and 400 milliarcseconds -- the data are extremely valuable in computing proper motions. In 1997, these positions were used to form the proper motions of the ACT Reference Catalogue. In 1999, USNO and Copenhagen University Observatory (CUO) partnered to create the Tycho-2 Catalogue. The CUO group re-analyzed the data from the Tycho experiment on the Hipparcos satellite. The USNO group re-analyzed over 140 positional catalogs which were combined with the expanded Tycho positions from the CUO group to compute the Tycho-2 proper motions. The largest contributor to these proper motions was the re-analyzed Astrographic Catalogue; the latest version being known as the AC 2000.2 Catalogue. There are two major differences between the AC 2000 and the AC 2000.2. First, the reference catalog used in AC 2000.2 was an expanded version of the Astrographic Catalogue Reference Stars that was rigorously derived on the Hipparcos Celestial Reference Frame. The second is that AC 2000.2 contains photometry from Tycho-2, where available. A description of the AC 2000.2 Catalogue, the reduction techniques used, how it compares with the 1997 version, and information on obtaining the data will be presented.

  13. Multispectral diffuse optical tomography of finger joints

    NASA Astrophysics Data System (ADS)

    Lighter, Daniel; Filer, Andrew; Dehghani, Hamid

    2017-07-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial inflammation. The current treatment paradigm for earlier, more aggressive therapy places importance on development of functional imaging modalities, capable of quantifying joint changes at the earliest stages. Diffuse optical tomography (DOT) has shown great promise in this regard, due to its cheap, non-invasive, non-ionizing and high contrast nature. Underlying pathological activity in afflicted joints leads to altered optical properties of the synovial region, with absorption and scattering increasing. Previous studies have used these optical changes as features for classifying diseased joints from healthy. Non-tomographic, single wavelength, continuous wave (CW) measurements of trans-illuminated joints have previously reported achieving this with specificity and sensitivity in the range 80 - 90% [1]. A single wavelength, frequency domain DOT system, combined with machine learning techniques, has been shown to achieve sensitivity and specificity in the range of 93.8 - 100% [2]. A CW system is presented here which collects data at 5 wavelengths, enabling reconstruction of pathophysiological parameters such as oxygenation and total hemoglobin, with the aim of identifying localized hypoxia and angiogenesis associated with inflammation in RA joints. These initial studies focus on establishing levels of variation in recovered parameters from images of healthy controls.

  14. Initial NIST AC QHR Measurements

    PubMed Central

    Cage, M. E.; Shields, S. H.; Jeffery, A.

    2004-01-01

    We demonstrate that dc quantized Hall resistance (dc QHR) guideline properties and dc and ac QHR values can be measured without changing sample probe lead connections at the QHR device, and report ac QHR values that converge to the dc QHR value when using four-terminal-pair ac QHR measurements. This was accomplished during one cooldown using single-series and quadruple-series connections outside the sample probe. The QHR was measured from 0 Hz to 5500 Hz in 1:1 ratio at 20 µA to ±1 part in 107 uncertainties with a poor-quality QHR device. A good device would allow an order of magnitude smaller uncertainties over this frequency range. We exchanged positions of the QHR device and reference resistor in the bridge and remeasured the resistance ratios to remove dominant ac bridge effects. PMID:27366620

  15. High resolution three-dimensional photoacoustic imaging of human finger joints in vivo

    NASA Astrophysics Data System (ADS)

    Xi, Lei; Jiang, Huabei

    2015-08-01

    We present a method for noninvasively imaging the hand joints using a three-dimensional (3D) photoacoustic imaging (PAI) system. This 3D PAI system utilizes cylindrical scanning in data collection and virtual-detector concept in image reconstruction. The maximum lateral and axial resolutions of the PAI system are 70 μm and 240 μm. The cross-sectional photoacoustic images of a healthy joint clearly exhibited major internal structures including phalanx and tendons, which are not available from the current photoacoustic imaging methods. The in vivo PAI results obtained are comparable with the corresponding 3.0 T MRI images of the finger joint. This study suggests that the proposed method has the potential to be used in early detection of joint diseases such as osteoarthritis.

  16. A preliminary evaluation of limb salvage surgery for osteosarcoma around knee joint.

    PubMed

    Wu, Xing; Cai, Zheng-Dong; Chen, Zheng-Rong; Yao, Zhen-Jun; Zhang, Guang-Jian

    2012-01-01

    To evaluate the effectiveness and drawbacks of diversified procedures of limb salvage surgery (LSS), providing a reference of rational surgical criterion of LSS. Fifty eight patients with stage IIB extremity osteosarcoma around knee joint area between 1992 and 2002 were studied retrospectively. Among them, 43 patients were treated by LSS followed by reconstruction. Reconstruction approaches included re-implantation of irradiation-devitalized tumor bone (n = 12), autoclaving-devitalized tumor bone (n = 8), prosthetic replacement (n = 11), allograft transplantation (n = 8) and vascularized fibula autograft implantation (n = 4). Amputations were performed in 15 patients. Patients were followed up for 6-16 years. There were no significant difference between LSS and amputation groups regarding disease free survival and local recurrence rates. The actuarial 5-year continuous disease free survival and local recurrence rate were 30.0% and 25.0% in patients of devitalized LSS group, whereas those were 56.5% and 8.7% in patients of non-devitalized reconstruction group. The complication rate was significantly higher in LSS group compared to amputation group (P = 0.003). LSS with non-devitalized procedures is the optimal treatment for osteosarcoma around knee joint area. Prosthesis implantation is the preferred option for bone reconstruction following LSS. Prevention and treatment of post-operative complications should be paid more attention to get good long-term outcomes of surgery.

  17. [Posttraumatic deformities of the knee joint : Intra-articular osteotomy after malreduction of tibial head fractures].

    PubMed

    Frosch, K-H; Krause, M; Frings, J; Drenck, T; Akoto, R; Müller, G; Madert, J

    2016-10-01

    Malreduction of tibial head fractures often leads to malalignment of the lower extremity, pain, limited range of motion and instability. The extent of the complaints and the degree of deformity requires an exact analysis and a standardized approach. True ligamentous instability should be distinguished from pseudoinstability of the joint. Also extra- and intra-articular deformities have to be differentiated. In intra-articular deformities the extent of articular surface displacement, defects and clefts must be accurately evaluated. A specific surgical approach is necessary, which allows adequate visualization, correct osteotomy and refixation of the fractured area of the tibial head. In the long-term course good clinical results are described for intra-articular osteotomies. If the joint is damaged to such an extent that it cannot be reconstructed or in cases of advanced posttraumatic osteoarthritis, total knee arthroplasty may be necessary; however, whenever possible and reasonable, anatomical reconstruction and preservation of the joint should be attempted.

  18. Is arthrocentesis of temporomandibular joint with corticosteroids beneficial? A systematic review.

    PubMed

    Davoudi, A; Khaki, H; Mohammadi, I; Daneshmand, M; Tamizifar, A; Bigdelou, M; Ansaripoor, F

    2018-05-01

    Temporomandibular disorders (TMDs) are musculoskeletal conditions that can inhibit the normal function of temporomandibular joints (TMJs) and affect the patient's quality of life, negatively. Arthrocentesis (AC) is a minimally invasive surgical procedure used for treating TMDs. The aim of present paper is to evaluate the advantages of administrating corticosteroid (CS) during AC by reviewing high quality released articles. Searching on Cochrane Library, Web of Science, Google Scholar, PubMed, ProQuest, and Scopus databases were performed with focusing on proper key words. Related titles and abstracts, up to December 2017, were screened and selected based on inclusion criteria. The full text of all randomized controlled trials (RCTs) was extensively read and subjected to quality assessments. After initial search, a total of 2067 articles were included into the study. Finally, 7 studies were reliable enough in methodology and randomization to be included into the study. All of the observed studies showed improvements in jaw functions and pain relief with no statistical differences in both AC and control groups. One study reported painless maximum incisal opening in CS group than the control group. Based on available RCTs, the AC of TMJ with CS seems to result in similar findings to other therapeutic drugs, with no significant differences.

  19. IL-8 -251T/A and IL-12B 1188A/C polymorphisms are associated with gout in a Chinese male population.

    PubMed

    Liu, S; Yin, C; Chu, N; Han, L; Li, C

    2013-01-01

    Gout is caused by monosodium urate (MSU) crystal-induced inflammation of the joints and periarticular tissues. MSU crystals activate NALP3 and mediate interleukin (IL)-1β generation from its inactive pro-form, resulting in cellular activation and an IL-8-mediated neutrophil influx into the joint. IL-8 and IL-12 are important chemokines related to the initiation and amplification of acute and chronic inflammatory processes. In this study, we investigated whether the IL-8 -251T/A and IL-12 1188A/C polymorphisms are associated with susceptibility to gout in a Chinese Han male population. Overall, 387 patients with gout and 576 controls were included in this study. Genotyping was performed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). An association analysis was carried out using the χ2 test. A genotype-phenotype analysis was also conducted. The T allele of IL-8 -251 was associated with risk of gout [p = 0.031 (odds ratio (OR) 1.229, 95% confidence interval (CI) 1.019-1.483]. There was a clear link between the IL-12 1188 AA and AC genotypic and A allelic frequencies between gout cases and controls (p < 0.001, df = 2 by genotype; p < 0.001, OR 1.404, 95% CI 1.165-1.691 by allele). Our results suggest that the IL-8 -251T/A and IL-12B 1188A/C polymorphisms may be relevant host susceptibility factors for the development of gout.

  20. Full statistical mode reconstruction of a light field via a photon-number-resolved measurement

    NASA Astrophysics Data System (ADS)

    Burenkov, I. A.; Sharma, A. K.; Gerrits, T.; Harder, G.; Bartley, T. J.; Silberhorn, C.; Goldschmidt, E. A.; Polyakov, S. V.

    2017-05-01

    We present a method to reconstruct the complete statistical mode structure and optical losses of multimode conjugated optical fields using an experimentally measured joint photon-number probability distribution. We demonstrate that this method evaluates classical and nonclassical properties using a single measurement technique and is well suited for quantum mesoscopic state characterization. We obtain a nearly perfect reconstruction of a field comprised of up to ten modes based on a minimal set of assumptions. To show the utility of this method, we use it to reconstruct the mode structure of an unknown bright parametric down-conversion source.

  1. Simultaneous Middle Third Clavicle Fracture and Type 3 Acromioclavicular Joint Dislocation; A Case Report

    PubMed Central

    Solooki, Saeed; Azad, Ali

    2014-01-01

    Simultaneous middle third clavicle fracture and acromioclavicular joint dislocation is a rare combination injury, as a result of high-energy trauma. We report a patient with a middle third clavicle fracture and ipsilateral grade three-acromioclavicular joint dislocation, which is a rare combination. The patient wanted to get back to work as soon as possible, so the fracture was fixed with reconstruction plate after open reduction and plate contouring; and acromioclavicular joint dislocation was reduced and fixed with two full threaded cancellous screws. One screw was inserted through the plate to the coracoid process. Clinical and radiographic finding revealed complete union of clavicle fracture and anatomical reduction of acromioclavicular joint with pain free full joint range of motion one year after operation. PMID:25207318

  2. Measurement of body joint angles for physical therapy based on mean shift tracking using two low cost Kinect images.

    PubMed

    Chen, Y C; Lee, H J; Lin, K H

    2015-08-01

    Range of motion (ROM) is commonly used to assess a patient's joint function in physical therapy. Because motion capture systems are generally very expensive, physical therapists mostly use simple rulers to measure patients' joint angles in clinical diagnosis, which will suffer from low accuracy, low reliability, and subjective. In this study we used color and depth image feature from two sets of low-cost Microsoft Kinect to reconstruct 3D joint positions, and then calculate moveable joint angles to assess the ROM. A Gaussian background model is first used to segment the human body from the depth images. The 3D coordinates of the joints are reconstructed from both color and depth images. To track the location of joints throughout the sequence more precisely, we adopt the mean shift algorithm to find out the center of voxels upon the joints. The two sets of Kinect are placed three meters away from each other and facing to the subject. The joint moveable angles and the motion data are calculated from the position of joints frame by frame. To verify the results of our system, we take the results from a motion capture system called VICON as golden standard. Our 150 test results showed that the deviation of joint moveable angles between those obtained by VICON and our system is about 4 to 8 degree in six different upper limb exercises, which are acceptable in clinical environment.

  3. Tissue Engineering: Step Ahead in Maxillofacial Reconstruction.

    PubMed

    Rai, Raj; Raval, Rushik; Khandeparker, Rakshit Vijay Sinai; Chidrawar, Swati K; Khan, Abdul Ahad; Ganpat, Makne Sachin

    2015-09-01

    Within the precedent decade, a new field of "tissue engineering" or "tissue regeneration" emerge that offers an innovative and exhilarating substitute for maxillofacial reconstruction. It offers a new option to supplement existing treatment regimens for reconstruction/regeneration of the oral and craniofacial complex, which includes the teeth, periodontium, bones, soft tissues (oral mucosa, conjunctiva, skin), salivary glands, and the temporomandibular joint (bone and cartilage), as well as blood vessels, muscles, tendons, and nerves. Tissue engineering is based on harvesting the stem cells which are having potential to form an organ. Harvested cells are then transferred into scaffolds that are manufactured in a laboratory to resemble the structure of the desired tissue to be replaced. This article reviews the principles of tissue engineering and its various applications in oral and maxillofacial surgery.

  4. Uncemented three-dimensional-printed prosthetic reconstruction for massive bone defects of the proximal tibia.

    PubMed

    Lu, Minxun; Li, Yongjiang; Luo, Yi; Zhang, Wenli; Zhou, Yong; Tu, Chongqi

    2018-03-06

    Currently, it is challenging to treat massive bone defects of proximal tibia. Although numerous methods are available for reconstruction with epiphysis preservation, limitations in knee function and complications are noted with these methods. Our paper describes our attempt to reconstruct a marked defect in the proximal tibia with an uncemented three-dimensional (3D)-printed prosthesis and to evaluate the prosthesis design and short-term outcomes. A 15-year-old boy with metaphyseal osteosarcoma of the tibia underwent intercalary allograft reconstruction following wide tumour resection with epiphysis preservation. However, chronic allograft rejection and/or infection occurred after the surgery and a sinus tract was formed. The rejection and/or infection process was successfully stopped by the removal of the graft and implantation of an antibiotic-loaded cement spacer; however, the limb function was poor. Because of the irregular shape of the defect and the excessively short length of the residual proximal tibia, we used the 3D printing technology to design and fabricate a personalised prosthesis to reconstruct the defect, with the preservation of the knee joint. At the last follow-up at 26 months, the patient had satisfactory limb function. The 3D-printed prosthesis may be a feasible option in the reconstruction of tibial metaphyseal defects with the preservation of the knee joint. Moreover, it can result in good postoperative function and low complication rates. However, a long-term follow-up is required to clarify its long-term outcomes.

  5. New Composites LnBDC@AC and CB[6]@AC: From Design toward Selective Adsorption of Methylene Blue or Methyl Orange

    PubMed Central

    Santos, Guilherme de C.; Barros, Amanda L.; de Oliveira, Carlos A. F.; da Luz, Leonis L.; da Silva, Fausthon F.; Demets, Grégoire J.-F.; Alves Júnior, Severino

    2017-01-01

    New porous composites LnBDC@AC (AC = Activated carbon, Ln = Eu and Gd and BDC = 1,4-benzenedicaboxylate) and CB[6]@AC (CB[6] = Cucurbit[6]uril) were obtained using hydrothermal route. The LnBDC and CB[B] are located inside the pore of the carbon materials as was observed in SEM-EDS, XRPD and FT-IR analysis. Porosimetry analysis showed values typically between AC and LnBDC material, with pore size and surface area, respectively, 29,56 Å and 353.98 m2g-1 for LnBDC@AC and 35,53 Å and 353.98 m2g-1 for CB[6]@AC. Both materials showed good absorptive capacity of metil orange (MO) and methylene blue (MB) with selectivity as a function of pH. For acid pH, both materials present selectivity by MB and alkaline pH for MO, with notable performance for CB[6]@AC. Additionally, europium luminescence was used as structural probe to investigate the coordination environment of Eu3+ ions in the EuBDC@AC composite after adsorption experiment. PMID:28107440

  6. A retrospective comparative study of arthroscopic fixation in acute Rockwood type IV acromioclavicular joint dislocation: single versus double paired Endobutton technique.

    PubMed

    Xu, Jian; Liu, Haifeng; Lu, Wei; Li, Dingfu; Zhu, Weimin; Ouyang, Kan; Wu, Bing; Peng, Liangquan; Wang, Daping

    2018-05-24

    Rockwood type IV acromioclavicular joint (ACJ) dislocation is a trauma usually needs surgical treatment. Paired EndoButton technique (PET) is used in treating such condition. However, the effect of using different types of PET (single versus double PET) for fixation remains controversial. This study aims to evaluate and compare the efficacy of single and double PET and to provide a suitable option for the surgeons. We retrospectively reviewed the charts of patients with acute Rockwood type IV ACJ dislocation who had undergone arthroscopic fixation using single or double PET fixation between March 2009 and March 2015. Seventy-eight consecutive patients identified from chart review were picked and were divided into the single and double PET group with 39 cases in each group. The indexes of visual analog scale score (VAS) for pain, the radiographs of the affected shoulder at different time points of the follow-up, the time of return to activities and sports, the constant functional score, and the Karlsson acromioclavicular joint (ACJ) score, were assessed in a minimum of 2 years postoperation. The average coracoclavicular (CC) and acromioclavicular (AC) distances of the affected joints in the double PET group were significantly smaller than those of the single PET group 2 years postoperation (P < 0.05). The average AC and CC distances in the healthy shoulder joints were significantly smaller than those of the affected joints in the single PET group (P < 0.05); however, these values were not significantly different from those of the affected joints in the double PET group (P > 0.05). The mean VAS pain score was not significantly different, while significant difference was found for the number and times of cases return to activities and sports, constant functional score, and Karlsson ACJ score (P < 0.05) between the two groups. Therefore, the double PET group has better outcome than the single PET group. Complications including redislocation, button

  7. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered slitlamp biomicroscope. 886.1850... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1850 AC-powered slitlamp biomicroscope. (a) Identification. An AC-powered slitlamp biomicroscope is an AC-powered device that is a...

  8. An analysis of early oncologic head and neck free flap reoperations from the 2005-2012 ACS-NSQIP dataset.

    PubMed

    Ligh, Cassandra A; Nelson, Jonas A; Wink, Jason D; Gerety, Patrick A; Fischer, John P; Wu, Liza C; Kanchwala, Suhail K

    2016-01-01

    There are limited population-based studies that examine perioperative factors that influence postoperative surgical take-backs to the OR following free flap (FF) reconstruction for head/neck cancer extirpation. The purpose of this study was to critically analyse head/neck free flaps (HNFF) captured in the ACS-NSQIP dataset with a specific focus on postoperative complications and the incidence of factors associated with re-operation. The 2005-2012 ACS-NSQIP datasets were accessed to identify patients undergoing FF reconstruction after a diagnosis of head/neck cancer. Patient demographics, comorbidities, and perioperative risk factors were examined as covariates, and the primary outcome was return to OR within 30 days of surgery. A multivariate regression was performed to determine independent preoperative factors associated with this complication. In total, 855 patients underwent FF for head/neck reconstruction most commonly for the Tongue (24.7%) and Mouth/Floor/cavity (25.0%). Of these, 153 patients (17.9%) returned to the OR within 30 days of surgery. Patients in this cohort had higher rates of wound infections and dehiscence (p < 0.01). Medical complications were significantly higher and included pneumonia (12.4% vs 5.0%, p < 0.01), prolonged ventilation (16.3% vs 4.8%, p < 0.01), myocardial infarction (2.6% vs 0.6%, p = 0.017), and sepsis (7.2% vs 3.4%, p = 0.033). Regression analysis demonstrated that visceral flaps (OR = 9.7, p = 0.012) and hypoalbuminemia (OR = 2.4, p = 0.009) were significant predictors of a return to the OR. Based on data from the nationwide NSQIP dataset, up to 17% of HNFF return to the OR within 30 days. Although this data-set has some significant limitations, these results can cautiously help to improve preoperative patient optimisation and surgical decision-making.

  9. Fatigue Strength and Related Characteristics of Aircraft Joints I : Comparison of Spot-Weld and Rivet Patterns in 24s-t Alclad and 75s-t Alclad

    NASA Technical Reports Server (NTRS)

    Russell, H W; Jackson, L R; Grover, H J; Beaver, W W

    1944-01-01

    Report contains detailed results of a number of fatigue tests on spot-welded joints in aluminum alloys. The tests described include: (1) fatigue tests on spot-welded lap joints in sheets of unequal thickness of alclad 24s-t. These tests indicate that the fatigue strength of a spot-welded joint in sheets of two different gages is slightly higher than that of a similar joint in two sheets of the thinner gage but definitely lower than that of a similar joint in two sheets of the thicker gage. (2) Fatigue tests on spot-welded alclad 75s-t spot-welded lap-joint specimens of alclad 75s-t were not any stronger in fatigue than similar specimens of alclad 24s-t. (3) Fatigue tests on lap-joint specimens spot -welded after various surface preparations--these included ac welding wire-brushed surfaces, dc welding wire-brushed surfaces, and dc welding chemically cleaned surfaces. While the ac welds were strongest statically, the dc welds on wire-brushed surfaces were strongest in fatigue. Specimens prepared in this way were very nearly as strong as the best riveted specimens tested for comparison. (4) Fatigue tests on specimens spot-welded with varying voltage so as to include a wide range of static spot-weld strengths. The fatigue strengths were in the same order as the static strengths but showed less range. (author)

  10. Investigation of practical initial attenuation image estimates in TOF-MLAA reconstruction for PET/MR

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cheng, Ju-Chieh, E-mail: chengjuchieh@gmail.com; Y

    Purpose: Time-of-flight joint attenuation and activity positron emission tomography reconstruction requires additional calibration (scale factors) or constraints during or post-reconstruction to produce a quantitative μ-map. In this work, the impact of various initializations of the joint reconstruction was investigated, and the initial average mu-value (IAM) method was introduced such that the forward-projection of the initial μ-map is already very close to that of the reference μ-map, thus reducing/minimizing the offset (scale factor) during the early iterations of the joint reconstruction. Consequently, the accuracy and efficiency of unconstrained joint reconstruction such as time-of-flight maximum likelihood estimation of attenuation and activity (TOF-MLAA)more » can be improved by the proposed IAM method. Methods: 2D simulations of brain and chest were used to evaluate TOF-MLAA with various initial estimates which include the object filled with water uniformly (conventional initial estimate), bone uniformly, the average μ-value uniformly (IAM magnitude initialization method), and the perfect spatial μ-distribution but with a wrong magnitude (initialization in terms of distribution). 3D GATE simulation was also performed for the chest phantom under a typical clinical scanning condition, and the simulated data were reconstructed with a fully corrected list-mode TOF-MLAA algorithm with various initial estimates. The accuracy of the average μ-values within the brain, chest, and abdomen regions obtained from the MR derived μ-maps was also evaluated using computed tomography μ-maps as the gold-standard. Results: The estimated μ-map with the initialization in terms of magnitude (i.e., average μ-value) was observed to reach the reference more quickly and naturally as compared to all other cases. Both 2D and 3D GATE simulations produced similar results, and it was observed that the proposed IAM approach can produce quantitative μ-map/emission when the

  11. Ankle Arthroscopic Reconstruction of Lateral Ligaments (Ankle Anti-ROLL)

    PubMed Central

    Takao, Masato; Glazebrook, Mark; Stone, James; Guillo, Stéphane

    2015-01-01

    Ankle instability is a condition that often requires surgery to stabilize the ankle joint that will improve pain and function if nonoperative treatments fail. Ankle stabilization surgery may be performed as a repair in which the native existing anterior talofibular ligament or calcaneofibular ligament (or both) is imbricated or reattached. Alternatively, when native ankle ligaments are insufficient for repair, a reconstruction of the ligaments may be performed in which an autologous or allograft tendon is used to reconstruct the anterior talofibular ligament or calcaneofibular ligament (or both). Currently, ankle stabilization surgery is most commonly performed through an open incision, but arthroscopic ankle stabilization using repair techniques has been described and is being used more often. We present our technique for anatomic ankle arthroscopic reconstruction of the lateral ligaments (anti-ROLL) performed in an all–inside-out manner that is likely safe for patients and minimally invasive. PMID:26900560

  12. A case report: reconstruction of a damaged knee following treatment of giant cell tumor of the proximal tibia with cryosurgery and cementation.

    PubMed

    Wakitani, S; Imoto, K; Saito, M; Yamamoto, T; Kawabata, H

    2002-05-01

    Reconstruction of a knee damaged by cement packed to cure a giant-cell tumor is sometimes difficult. We reconstructed such a knee by removal of the cement, autologous bone transplantation and distraction osteogenesis using the Ilizarov apparatus. In this paper the results 29 months after the salvage surgery are given. We saw a 31-year-old woman's knee joint that showed osteoarthritic change after curettage, cryosurgery and cementation performed 4 years previously for a giant-cell tumor of the proximal tibia. We reconstructed the knee joint. This procedure included cement removal, alignment correction by tibial osteotomy, subchondral bone reconstruction by autologous bone transplantation, and filling the defect after removing the bone cement by elongating the diaphysis using the Ilizarov apparatus. Distraction was terminated 4 months later when 54 mm of elongation was performed. All devices were removed 12 months after the surgery. Seventeen months after the removal of the apparatus, the range of motion of the right knee was 0 degrees extension and 110 degrees flexion, and the patient was able to walk without pain. Although the treatment period is long and there may be some complications of Ilizarov lengthening and distraction osteogenesis, this procedure has numerous benefits. Bony defects can be soundly reconstructed and, at the same time, the alignment of the knee can be corrected. Also it is not necessary to reconstruct the ligaments because the insertions are intact. If osteoarthritis progresses, a surface type total knee replacement can be performed, not constrained type prosthesis, which would be used if the bony structure had not been reconstructed. This procedure may be one of the candidates for reconstructing such knee joints destroyed by bone cement. Copyright 2002 OsteoArthritis Research Society International. Published by Elsevier Science Ltd. All rights reserved.

  13. Super-resolution photoacoustic microscopy using joint sparsity

    NASA Astrophysics Data System (ADS)

    Burgholzer, P.; Haltmeier, M.; Berer, T.; Leiss-Holzinger, E.; Murray, T. W.

    2017-07-01

    We present an imaging method that uses the random optical speckle patterns that naturally emerge as light propagates through strongly scattering media as a structured illumination source for photoacoustic imaging. Our approach, termed blind structured illumination photoacoustic microscopy (BSIPAM), was inspired by recent work in fluorescence microscopy where super-resolution imaging was demonstrated using multiple unknown speckle illumination patterns. We extend this concept to the multiple scattering domain using photoacoustics (PA), with the speckle pattern serving to generate ultrasound. The optical speckle pattern that emerges as light propagates through diffuse media provides structured illumination to an object placed behind a scattering wall. The photoacoustic signal produced by such illumination is detected using a focused ultrasound transducer. We demonstrate through both simulation and experiment, that by acquiring multiple photoacoustic images, each produced by a different random and unknown speckle pattern, an image of an absorbing object can be reconstructed with a spatial resolution far exceeding that of the ultrasound transducer. We experimentally and numerically demonstrate a gain in resolution of more than a factor of two by using multiple speckle illuminations. The variations in the photoacoustic signals generated with random speckle patterns are utilized in BSIPAM using a novel reconstruction algorithm. Exploiting joint sparsity, this algorithm is capable of reconstructing the absorbing structure from measured PA signals with a resolution close to the speckle size. Another way to excite random excitation for photoacoustic imaging are small absorbing particles, including contrast agents, which flow through small vessels. For such a set-up, the joint-sparsity is generated by the fact that all the particles move in the same vessels. Structured illumination in that case is not necessary.

  14. A cross-platform freeware tool for digital reconstruction of neuronal arborizations from image stacks.

    PubMed

    Brown, Kerry M; Donohue, Duncan E; D'Alessandro, Giampaolo; Ascoli, Giorgio A

    2005-01-01

    Digital reconstruction of neuronal arborizations is an important step in the quantitative investigation of cellular neuroanatomy. In this process, neurites imaged by microscopy are semi-manually traced through the use of specialized computer software and represented as binary trees of branching cylinders (or truncated cones). Such form of the reconstruction files is efficient and parsimonious, and allows extensive morphometric analysis as well as the implementation of biophysical models of electrophysiology. Here, we describe Neuron_ Morpho, a plugin for the popular Java application ImageJ that mediates the digital reconstruction of neurons from image stacks. Both the executable and code of Neuron_ Morpho are freely distributed (www.maths. soton.ac.uk/staff/D'Alessandro/morpho or www.krasnow.gmu.edu/L-Neuron), and are compatible with all major computer platforms (including Windows, Mac, and Linux). We tested Neuron_Morpho by reconstructing two neurons from each of the two preparations representing different brain areas (hippocampus and cerebellum), neuritic type (pyramidal cell dendrites and olivar axonal projection terminals), and labeling method (rapid Golgi impregnation and anterograde dextran amine), and quantitatively comparing the resulting morphologies to those of the same cells reconstructed with the standard commercial system, Neurolucida. None of the numerous morphometric measures that were analyzed displayed any significant or systematic difference between the two reconstructing systems.

  15. High-Frequency ac Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.; Mildice, James

    1987-01-01

    Loads managed automatically under cycle-by-cycle control. 440-V rms, 20-kHz ac power system developed. System flexible, versatile, and "transparent" to user equipment, while maintaining high efficiency and low weight. Electrical source, from dc to 2,200-Hz ac converted to 440-V rms, 20-kHz, single-phase ac. Power distributed through low-inductance cables. Output power either dc or variable ac. Energy transferred per cycle reduced by factor of 50. Number of parts reduced by factor of about 5 and power loss reduced by two-thirds. Factors result in increased reliability and reduced costs. Used in any power-distribution system requiring high efficiency, high reliability, low weight, and flexibility to handle variety of sources and loads.

  16. 78 FR 39345 - ACS Wireless, Inc.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-01

    ... on July 31, 1995 under the name MACTEL INC. Alaska Communications Systems Group, Inc. (``ACS Group...-owned subsidiary of ACS Group, held through ACS Group's wholly-owned subsidiary Alaska Communications... presently an investment company as defined in section 3(a) of the Act. 2. On June 4, 2012, ACS Group, ACS...

  17. Soft-Tissue Reconstruction of the Complicated Knee Arthroplasty: Principles and Predictors of Salvage.

    PubMed

    Colen, David L; Carney, Martin J; Shubinets, Valeriy; Lanni, Michael A; Liu, Tiffany; Levin, L Scott; Lee, Gwo-Chin; Kovach, Stephen J

    2018-04-01

    Total knee arthroplasty is a common orthopedic procedure in the United States and complications can be devastating. Soft-tissue compromise or joint infection may cause failure of prosthesis requiring knee fusion or amputation. The role of a plastic surgeon in total knee arthroplasty is critical for cases requiring optimization of the soft-tissue envelope. The purpose of this study was to elucidate factors associated with total knee arthroplasty salvage following complications and clarify principles of reconstruction to optimize outcomes. A retrospective review of patients requiring soft-tissue reconstruction performed by the senior author after total knee arthroplasty over 8 years was completed. Logistic regression and Fisher's exact tests determined factors associated with the primary outcome, prosthesis salvage versus knee fusion or amputation. Seventy-three knees in 71 patients required soft-tissue reconstruction (mean follow-up, 1.8 years), with a salvage rate of 61.1 percent, mostly using medial gastrocnemius flaps. Patients referred to our institution with complicated periprosthetic wounds were significantly more likely to lose their knee prosthesis than patients treated only within our system. Patients with multiple prior knee operations before definitive soft-tissue reconstruction had significantly decreased rates of prosthesis salvage and an increased risk of amputation. Knee salvage significantly decreased with positive joint cultures (Gram-negative greater than Gram-positive organisms) and particularly at the time of definitive reconstruction, which also trended toward an increased risk of amputation. In revision total knee arthroplasty, prompt soft-tissue reconstruction improves the likelihood of success, and protracted surgical courses and contamination increase failure and amputations. The authors show a benefit to involving plastic surgeons early in the course of total knee arthroplasty complications to optimize genicular soft tissues. Therapeutic

  18. Multi-disciplinary management of complex pressure sore reconstruction: 5-year review of experience in a spinal injuries centre

    PubMed Central

    Choudry, M; White, C; Mecci, M; Siddiqui, H

    2017-01-01

    INTRODUCTION In our regional spinal injuries unit, complex pressure ulcer reconstruction is facilitated by a monthly multidisciplinary team clinic. This study reviews a series of the more complex of these patients who underwent surgery as a joint case between plastics and other surgical specialties, aiming to provide descriptive data as well as share the experience of treating these complex wounds. MATERIALS AND METHODS Patients operated on as a joint case from 2010 to 2014 were identified through a locally held database and hospital records were then retrospectively reviewed for perioperative variables. Descriptive statistics were collected. RESULTS 12 patients underwent 15 procedures as a joint collaboration between plastic surgery and other surgical specialties: one with spinal surgery, 12 with orthopaedic and two with both orthopaedic and urology involvement. Ischial and trochanteric wounds accounted for 88% of cases with five Girdlestone procedures being performed and 12 requiring soft-tissue flap reconstruction. Mean operative time was 3.8hours. Four patients required high-dependency care and 13 patients received long-term antibiotics. Only three minor complications (20%) were seen with postoperative wound dehiscence. DISCUSSION The multidisciplinary team clinic allows careful assessment and selection of patients appropriate for surgical reconstruction and to help match expectations and limitations imposed by surgery, which are likely to influence their current lifestyle in this largely independent patient group. Collaboration with other specialties gives the best surgical outcome both for the present episode as well as leaving avenues open for potential future reconstruction. PMID:27490980

  19. Joint water-fat separation and deblurring for spiral imaging.

    PubMed

    Wang, Dinghui; Zwart, Nicholas R; Pipe, James G

    2018-06-01

    Most previous approaches to spiral Dixon water-fat imaging perform the water-fat separation and deblurring sequentially based on the assumption that the phase accumulation and blurring as a result of off-resonance are separable. This condition can easily be violated in regions where the B 0 inhomogeneity varies rapidly. The goal of this work is to present a novel joint water-fat separation and deblurring method for spiral imaging. The proposed approach is based on a more accurate signal model that takes into account the phase accumulation and blurring simultaneously. A conjugate gradient method is used in the image domain to reconstruct the deblurred water and fat iteratively. Spatially varying convolutions with a local convergence criterion are used to reduce the computational demand. Both simulation and high-resolution brain imaging have demonstrated that the proposed joint method consistently improves the quality of reconstructed water and fat images compared with the sequential approach, especially in regions where the field inhomogeneity changes rapidly in space. The loss of signal-to-noise-ratio as a result of deblurring is minor at optimal echo times. High-quality water-fat spiral imaging can be achieved with the proposed joint approach, provided that an accurate field map of B 0 inhomogeneity is available. Magn Reson Med 79:3218-3228, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  20. Anatomic double-bundle anterior cruciate ligament reconstruction restores patellofemoral contact areas and pressures more closely than nonanatomic single-bundle reconstruction.

    PubMed

    Tajima, Goro; Iriuchishima, Takanori; Ingham, Sheila J M; Shen, Wei; van Houten, Albert H; Aerts, Maarten M; Shimamura, Tadashi; Smolinski, Patrick; Fu, Freddie H

    2010-10-01

    To investigate the effects of anterior cruciate ligament (ACL) deficiency and nonanatomic single-bundle (SB) and anatomic double-bundle (DB) ACL reconstruction on the contact characteristics of the patellofemoral (PF) joint. By use of a materials testing system, 7 fresh-frozen human cadaveric knees were tested. The following states were tested: ACL-intact knee, nonanatomic SB ACL reconstruction, anatomic DB ACL reconstruction, and ACL-deficient knee. Hamstring autografts were used. PF contact pressures and areas were measured with pressure-sensitive film at 30°, 60°, and 90° of knee flexion with a constant 100-N load on the quadriceps tendon. The total contact area of ACL-deficient and nonanatomic SB ACL-reconstructed knees (123.8 ± 63.9 and 149.6 ± 79.3 mm(2), respectively) significantly decreased when compared with those of the intact knee (206.1 ± 83.6 mm(2)) at 30° of knee flexion. The lateral-facet peak pressure of ACL-deficient and nonanatomic SB ACL-reconstructed knees (1.12 ± 0.52 and 1.22 ± 0.54 MPa, respectively) significantly decreased when compared with those of the intact knee (0.68 ± 0.38 MPa) at 90° of knee flexion. Anatomic DB ACL reconstruction restored the contact pressures and areas to values similar to those of the intact knee (no significant difference). ACL deficiency resulted in a significant decrease in the total and medial PF contact areas and in an increase in the lateral PF contact pressure. Anatomic DB ACL reconstruction more closely restored normal PF contact area and pressure than did nonanatomic SB ACL reconstruction. Our findings suggest that the changes in the PF contact area and pressures in ACL deficiency and after nonanatomic SB ACL reconstruction may be one of the causes of PF osteoarthritis or other related PF problems found at long-term follow-up. Anatomic DB ACL reconstruction may reduce the incidence of PF problems by closely restoring the contact area and pressure. Copyright © 2010 Arthroscopy Association of

  1. The metatarsosesamoid joint: an in vitro 3D quantitative assessment.

    PubMed

    Jamal, Bilal; Pillai, Anand; Fogg, Quentin; Kumar, Senthil

    2015-03-01

    The anatomy of the first metatarsophalangeal (MTP) joint, particularly the metatarsosesamoid articulation, remains poorly understood. Our goal was to quantitatively define the excursion of the sesamoids. Seven cadavers were dissected to assess the articulating surfaces throughout a normal range of motion. The dissections were digitally reconstructed in various positions using a MicroScribe. For first MTP joint, excursion averaged 14.7mm for the tibial sesamoid in the sagittal plane and 7.5mm for the fibular sesamoid. The sesamoids also moved medially to laterally when the joint was dorsiflexed. For the maximally dorsiflexed joint, excursion averaged 2.8mm for the tibial sesamoid and 3.5mm for the fibular sesamoid. Hallucal sesamoids appear to have differential tracking: the tibial sesamoid has greater longitudinal excursion; the fibular sesamoid has greater lateral excursion. The anatomical data will interest those involved with the design of an effective hallux arthroplasty. Copyright © 2014 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  2. The Effects of High-Intensity versus Low-Intensity Resistance Training on Leg Extensor Power and Recovery of Knee Function after ACL-Reconstruction

    PubMed Central

    Aue Sobol, Nanna; Andersen, Lars L.; Kiel, Peter; Løfholm, Peter; Magnusson, S. Peter; Krogsgaard, Michael R.

    2014-01-01

    Objective. Persistent weakness is a common problem after anterior cruciate ligament- (ACL-) reconstruction. This study investigated the effects of high-intensity (HRT) versus low-intensity (LRT) resistance training on leg extensor power and recovery of knee function after ACL-reconstruction. Methods. 31 males and 19 females were randomized to HRT (n = 24) or LRT (n = 26) from week 8–20 after ACL-reconstruction. Leg extensor power, joint laxity, and self-reported knee function were measured before and 7, 14, and 20 weeks after surgery. Hop tests were assessed before and after 20 weeks. Results. Power in the injured leg was 90% (95% CI 86–94%) of the noninjured leg, decreasing to 64% (95% CI 60–69%) 7 weeks after surgery. During the resistance training phase there was a significant group by time interaction for power (P = 0.020). Power was regained more with HRT compared to LRT at week 14 (84% versus 73% of noninjured leg, resp.; P = 0.027) and at week 20 (98% versus 83% of noninjured leg, resp.; P = 0.006) without adverse effects on joint laxity. No other between-group differences were found. Conclusion. High-intensity resistance training during rehabilitation after ACL-reconstruction can improve muscle power without adverse effects on joint laxity. PMID:24877078

  3. AC conductivity and dielectric behavior of bulk Furfurylidenemalononitrile

    NASA Astrophysics Data System (ADS)

    El-Nahass, M. M.; Ali, H. A. M.

    2012-06-01

    AC conductivity and dielectric behavior for bulk Furfurylidenemalononitrile have been studied over a temperature range (293-333 K) and frequency range (50-5×106 Hz). The frequency dependence of ac conductivity, σac, has been investigated by the universal power law, σac(ω)=Aωs. The variation of the frequency exponent (s) with temperature was analyzed in terms of different conduction mechanisms, and it was found that the correlated barrier hopping (CBH) model is the predominant conduction mechanism. The temperature dependence of σac(ω) showed a linear increase with the increase in temperature at different frequencies. The ac activation energy was determined at different frequencies. Dielectric data were analyzed using complex permittivity and complex electric modulus for bulk Furfurylidenemalononitrile at various temperatures.

  4. Recent advances and future directions in the management of knee osteoarthritis: Can biological joint reconstruction replace joint arthroplasty and when?

    PubMed Central

    Paschos, Nikolaos K

    2015-01-01

    In this article, a concise description of the recent advances in the field of osteoarthritis management is presented. The main focus is to highlight the most promising techniques that emerge in both biological joint replacement and artificial joint arthroplasty. A critical view of high quality evidence regarding outcome and safety profile of these techniques is presented. The potential role of kinematically aligned total knee replacement, navigation, and robotic-assisted surgery is outlined. A critical description of both primary and stem cell-based therapies, the cell homing theory, the use of biologic factors and recent advancements in tissue engineering and regenerative medicine is provided. Based on the current evidence, some thoughts on a realistic approach towards answering these questions are attempted. PMID:26495242

  5. Insufficient sensitivity of joint aspiration during the two-stage exchange of the hip with spacers.

    PubMed

    Boelch, Sebastian Philipp; Weissenberger, Manuel; Spohn, Frederik; Rudert, Maximilian; Luedemann, Martin

    2018-01-10

    Evaluation of infection persistence during the two-stage exchange of the hip is challenging. Joint aspiration before reconstruction is supposed to rule out infection persistence. Sensitivity and specificity of synovial fluid culture and synovial leucocyte count for detecting infection persistence during the two-stage exchange of the hip were evaluated. Ninety-two aspirations before planned joint reconstruction during the two-stage exchange with spacers of the hip were retrospectively analyzed. The sensitivity and specificity of synovial fluid culture was 4.6 and 94.3%. The sensitivity and specificity of synovial leucocyte count at a cut-off value of 2000 cells/μl was 25.0 and 96.9%. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values were significantly higher before prosthesis removal and reconstruction or spacer exchange (p = 0.00; p = 0.013 and p = 0.039; p = 0.002) in the infection persistence group. Receiver operating characteristic area under the curve values before prosthesis removal and reconstruction or spacer exchange for ESR were lower (0.516 and 0.635) than for CRP (0.720 and 0.671). Synovial fluid culture and leucocyte count cannot rule out infection persistence during the two-stage exchange of the hip.

  6. The anatomy of the anterior cruciate ligament and its relevance to the technique of reconstruction.

    PubMed

    Śmigielski, R; Zdanowicz, U; Drwięga, M; Ciszek, B; Williams, A

    2016-08-01

    Anterior cruciate ligament (ACL) reconstruction is commonly performed and has been for many years. Despite this, the technical details related to ACL anatomy, such as tunnel placement, are still a topic for debate. In this paper, we introduce the flat ribbon concept of the anatomy of the ACL, and its relevance to clinical practice. Cite this article: Bone Joint J 2016;98-B:1020-6. ©2016 The British Editorial Society of Bone & Joint Surgery.

  7. Pixel-based CTE Correction of ACS/WFC: Modifications To The ACS Calibration Pipeline (CALACS)

    NASA Astrophysics Data System (ADS)

    Smith, Linda J.; Anderson, J.; Armstrong, A.; Avila, R.; Bedin, L.; Chiaberge, M.; Davis, M.; Ferguson, B.; Fruchter, A.; Golimowski, D.; Grogin, N.; Hack, W.; Lim, P. L.; Lucas, R.; Maybhate, A.; McMaster, M.; Ogaz, S.; Suchkov, A.; Ubeda, L.

    2012-01-01

    The Advanced Camera for Surveys (ACS) was installed on the Hubble Space Telescope (HST) nearly ten years ago. Over the last decade, continuous exposure to the harsh radiation environment has degraded the charge transfer efficiency (CTE) of the CCDs. The worsening CTE impacts the science that can be obtained by altering the photometric, astrometric and morphological characteristics of sources, particularly those farthest from the readout amplifiers. To ameliorate these effects, Anderson & Bedin (2010, PASP, 122, 1035) developed a pixel-based empirical approach to correcting ACS data by characterizing the CTE profiles of trails behind warm pixels in dark exposures. The success of this technique means that it is now possible to correct full-frame ACS/WFC images for CTE degradation in the standard data calibration and reduction pipeline CALACS. Over the past year, the ACS team at STScI has developed, refined and tested the new software. The details of this work are described in separate posters. The new code is more effective at low flux levels (< 50 electrons) than the original Anderson & Bedin code, and employs a more accurate time and temperature dependence for CTE. The new CALACS includes the automatic removal of low-level bias stripes (produced by the post-repair ACS electronics) and pixel-based CTE correction. In addition to the standard cosmic ray corrected, flat-fielded and drizzled data products (crj, flt and drz files) there are three new equivalent files (crc, flc and drc) which contain the CTE-corrected data products. The user community will be able to choose whether to use the standard or CTE-corrected products.

  8. [Chronic ankle joint instability: in unrecognized distal rupture of the syndosmosis and malunion of the distal fibula].

    PubMed

    Michelitsch, C; Acklin, Y P; Stoffel, K; Bereiter, H

    2014-04-01

    It is often difficult in the acute phase to diagnose a lesion of the distal tibiofibular syndesmosis. If this lesion is overlooked, the patient will develop an incongruity of the upper ankle joint with a pathological external rotation of the talus. The risk of a possible premature arthritis is clearly increased. In this case study a distal rupture of the syndesmosis in a young patient was overlooked in the initial diagnostic work-up. A search of the relevant literature and a case report. In the case described the shortened fibula and chronic instability of the tibiofibular syndesmosis were repaired with a lengthening and derotational osteotomy and reconstruction using the gracilis muscle tendon. Through this method an exact reconstruction of the normal anatomy could be achieved. Posttraumatic misalignment in the ankle joint is associated with a high risk of secondary degenerative lesions. In cases with suspicion of a syndesmosis lesion, confirmation of the diagnosis is imperative so as to perform an anatomic repositioning and reconstruction of stability.

  9. Assay Methods for ACS Activity and ACS Phosphorylation by MAP Kinases In Vitro and In Vivo.

    PubMed

    Han, Xiaomin; Li, Guojing; Zhang, Shuqun

    2017-01-01

    Ethylene, a gaseous phytohormone, has profound effects on plant growth, development, and adaptation to the environment. Ethylene-regulated processes begin with the induction of ethylene biosynthesis. There are two key steps in ethylene biosynthesis. The first is the biosynthesis of 1-aminocyclopropane-1-carboxylic acid (ACC) from S-Adenosyl-Methionine (SAM), a common precursor in many metabolic pathways, which is catalyzed by ACC synthase (ACS). The second is the oxidative cleavage of ACC to form ethylene under the action of ACC oxidase (ACO). ACC biosynthesis is the committing and generally the rate-limiting step in ethylene biosynthesis. As a result, characterizing the cellular ACS activity and understanding its regulation are important. In this chapter, we detail the methods used to measure, (1) the enzymatic activity of both recombinant and native ACS proteins, and (2) the phosphorylation of ACS protein by mitogen-activated protein kinases (MAPKs) in vivo and in vitro.

  10. Quadriceps Muscle Function After Rehabilitation With Cryotherapy in Patients With Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Hart, Joseph M.; Kuenze, Christopher M.; Diduch, David R.; Ingersoll, Christopher D.

    2014-01-01

    Context: Persistent muscle weakness after anterior cruciate ligament (ACL) reconstruction may be due to underlying activation failure and arthrogenic muscle inhibition (AMI). Knee-joint cryotherapy has been shown to improve quadriceps function transiently in those with AMI, thereby providing an opportunity to improve quadriceps muscle activation and strength in patients with a reconstructed ACL. Objective: To compare quadriceps muscle function in patients with a reconstructed ACL who completed a 2-week intervention including daily cryotherapy (ice bag), daily exercises, or both. Design: Cross-sectional study. Setting: Laboratory. Patients or Other Participants: A total of 30 patients with reconstructed ACLs who were at least 6 months post-index surgery and had measurable quadriceps AMI. Intervention(s): The patients attended 4 supervised visits over a 2-week period. They were randomly assigned to receive 20 minutes of knee-joint cryotherapy, 1 hour of therapeutic rehabilitation exercises, or cryotherapy followed by exercises. Main Outcome Measure(s): We measured quadriceps Hoffmann reflex, normalized maximal voluntary isometric contraction torque, central activation ratio using the superimposed-burst technique, and patient-reported outcomes before and after the intervention period. Results: After the 2-week intervention period, patients who performed rehabilitation exercises immediately after cryotherapy had higher normalized maximal voluntary isometric contraction torques (P = .002, Cohen d effect size = 1.4) compared with those who received cryotherapy alone (P = .16, d = 0.58) or performed exercise alone (P = .16, d = 0.30). Conclusions: After ACL reconstruction, patients with AMI who performed rehabilitation exercises immediately after cryotherapy experienced greater strength gains than those who performed cryotherapy or exercises alone. PMID:25299442

  11. Open Dislocation of the High Ankle Joint After Fibular Graft Harvesting.

    PubMed

    Anđelković, Slađana Z; Vučković, Čedo Đ; Palibrk, Tomislav D; Milutinović, Suzana M; Bumbaširević, Marko Ž

    2015-01-01

    The free microvascular fibula and soft tissue transfer has become a widely used method for reconstruction of different regions. Donor site morbidity for free fibula microvascular flaps has generally been reported to be low, or at least acceptable. We describe the case of a patient who underwent vascularized free fibula graft harvest for mandibular reconstruction. After 21 months, he had sustained an open dislocation of the left high ankle joint during recreational sports activity. We did not found such case in the published data. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  12. [Treatment Strategies for Septic Arthritis of the Sternoclavicular Joint].

    PubMed

    Kuhtin, O; Schmidt-Rohlfing, B; Dittrich, M; Lampl, L; Hohls, M; Haas, V

    2015-10-01

    Septic arthritis of the sternoclavicular joint (SCJ) is a relatively rare disease. Due to serious complications including mediastinitis and generalised sepsis early diagnosis and rapid onset of treatment are mandatory. The disease often affects immunocompromised patients, diabetics, or patients with other infectious diseases. The therapeutic options range from administration of antibiotics to extended surgery including reconstructive procedures. Apart from rare situations where conservative treatment with antibiotics is sufficient, joint resection followed by plastic surgical procedures are required. We present a retrospective analysis with data from two hospitals. From January 2008 to December 2012 23 patients with radiographically confirmed septic arthritis of various aetiology were included. Fourteen (60.8 %) male, nine (39.2 %) female patients with an average age of 60.3 ± 14.2 years (range: 23-88 years) with septic arthritis of the SCJ were treated. Seven (30.4 %) patients suffered from Diabetes mellitus, nine (39.1 %) had underlying diseases with a compromised immune system. In 14 (60.8 %) out of 23 patients a bacterial focus was detected. Only six (26 %) patients suffered from confined septic arthritis of the SCG, in 17 (73,9 %) patients osteomyelitis of the adjacent sternum, and the clavicle was present. In addition, 15 (65.2 %) patients already suffered from mediastinitis at the time of diagnosis, eight (35 %) patients even from septicaemia. In conclusion, septic arthritis requires an active surgical treatment. Limited incision of the joint and debridement alone is only successful at early stages of the disease. The treatment concept has to include the local joint and bone resection as well as complications like mediastinitis. After successful treatment of the infection, the defect of the chest wall requires secondary reconstructive surgery using a pedicled pectoralis muscle flap. Georg Thieme Verlag KG Stuttgart · New York.

  13. Shoulder arthrodesis with a reconstruction plate

    PubMed Central

    Byeon, Hwa Kyo

    2008-01-01

    From 1995 to 2005, arthrodesis with a reconstruction plate was performed for eight shoulders. The average follow-up period was 44 months. The indications for shoulder arthrodesis were joint destruction as a sequel of tuberculous arthritis, malignant bone tumour, pyogenic arthritis, failed arthrodesis and paralysis of the brachial plexus. The evaluation criteria included bony union and pain. Two cases of malignant tumour required an homologous bone graft due to severe bone deficit—a fracture that occurred in the distal part of the arthrodesed shoulder after removing the plate. With the exception of these two cases, severe pain or other complications did not occur in any other case. Shoulder arthrodesis with a reconstruction plate was judged to be a useful method for glenohumeral salvage in cases without severe bone deficit. Further, additional treatment methods should be considered to prevent fracture that may occur as a result of severe bone deficit. PMID:18716728

  14. Optimal Joint Remote State Preparation of Arbitrary Equatorial Multi-qudit States

    NASA Astrophysics Data System (ADS)

    Cai, Tao; Jiang, Min

    2017-03-01

    As an important communication technology, quantum information transmission plays an important role in the future network communication. It involves two kinds of transmission ways: quantum teleportation and remote state preparation. In this paper, we put forward a new scheme for optimal joint remote state preparation (JRSP) of an arbitrary equatorial two-qudit state with hybrid dimensions. Moreover, the receiver can reconstruct the target state with 100 % success probability in a deterministic manner via two spatially separated senders. Based on it, we can extend it to joint remote preparation of arbitrary equatorial multi-qudit states with hybrid dimensions using the same strategy.

  15. Gamma-irradiation produces active chlorine species (ACS) in physiological solutions: Secoisolariciresinol diglucoside (SDG) scavenges ACS - A novel mechanism of DNA radioprotection

    PubMed Central

    Mishra, Om P.; Popov, Anatoliy V.; Pietrofesa, Ralph A.; Christofidou-Solomidou, Melpo

    2017-01-01

    Background Secoisolariciresinol diglucoside (SDG), the main lignan in whole grain flaxseed, is a potent antioxidant and free radical scavenger with known radioprotective properties. However, the exact mechanism of SDG radioprotection is not well understood. The current study identified a novel mechanism of DNA radioprotection by SDG in physiological solutions by scavenging active chlorine species (ACS) and reducing chlorinated nucleobases. Methods The ACS scavenging activity of SDG was determined using two highly specific fluoroprobes: hypochlorite-specific 3′-(p-aminophenyl) fluorescein (APF) and hydroxyl radical-sensitive 3′-(p-hydroxyphenyl) fluorescein (HPF). Dopamine, an SDG structural analog, was used for proton 1H NMR studies to trap primary ACS radicals. Taurine N-chlorination was determined to demonstrate radiation-induced generation of hypochlorite, a secondary ACS. DNA protection was assessed by determining the extent of DNA fragmentation and plasmid DNA relaxation following exposure to ClO− and radiation. Purine base chlorination by ClO− and γ-radiation was determined by using 2-aminopurine (2-AP), a fluorescent analog of 6-aminopurine. Results: Chloride anions (Cl−) consumed >90% of hydroxyl radicals in physiological solutions produced by γ-radiation resulting in ACS formation, which was detected by 1H NMR. Importantly, SDG scavenged hypochlorite- and γ-radiation-induced ACS. In addition, SDG blunted ACS-induced fragmentation of calf thymus DNA and plasmid DNA relaxation. SDG treatment before or after ACS exposure decreased the ClO− or γ-radiation-induced chlorination of 2-AP. Exposure to γ-radiation resulted in increased taurine chlorination, indicative of ClO− generation. NMR studies revealed formation of primary ACS radicals (chlorine atoms (Cl•) and dichloro radical anions (Cl2−•)), which were trapped by SDG and its structural analog dopamine. Conclusion We demonstrate that γ-radiation induces the generation of ACS in

  16. Gamma-irradiation produces active chlorine species (ACS) in physiological solutions: Secoisolariciresinol diglucoside (SDG) scavenges ACS - A novel mechanism of DNA radioprotection.

    PubMed

    Mishra, Om P; Popov, Anatoliy V; Pietrofesa, Ralph A; Christofidou-Solomidou, Melpo

    2016-09-01

    Secoisolariciresinol diglucoside (SDG), the main lignan in whole grain flaxseed, is a potent antioxidant and free radical scavenger with known radioprotective properties. However, the exact mechanism of SDG radioprotection is not well understood. The current study identified a novel mechanism of DNA radioprotection by SDG in physiological solutions by scavenging active chlorine species (ACS) and reducing chlorinated nucleobases. The ACS scavenging activity of SDG was determined using two highly specific fluoroprobes: hypochlorite-specific 3'-(p-aminophenyl) fluorescein (APF) and hydroxyl radical-sensitive 3'-(p-hydroxyphenyl) fluorescein (HPF). Dopamine, an SDG structural analog, was used for proton (1)H NMR studies to trap primary ACS radicals. Taurine N-chlorination was determined to demonstrate radiation-induced generation of hypochlorite, a secondary ACS. DNA protection was assessed by determining the extent of DNA fragmentation and plasmid DNA relaxation following exposure to ClO(-) and radiation. Purine base chlorination by ClO(-) and γ-radiation was determined by using 2-aminopurine (2-AP), a fluorescent analog of 6-aminopurine. Chloride anions (Cl(-)) consumed >90% of hydroxyl radicals in physiological solutions produced by γ-radiation resulting in ACS formation, which was detected by (1)H NMR. Importantly, SDG scavenged hypochlorite- and γ-radiation-induced ACS. In addition, SDG blunted ACS-induced fragmentation of calf thymus DNA and plasmid DNA relaxation. SDG treatment before or after ACS exposure decreased the ClO(-) or γ-radiation-induced chlorination of 2-AP. Exposure to γ-radiation resulted in increased taurine chlorination, indicative of ClO(-) generation. NMR studies revealed formation of primary ACS radicals (chlorine atoms (Cl) and dichloro radical anions (Cl2¯)), which were trapped by SDG and its structural analog dopamine. We demonstrate that γ-radiation induces the generation of ACS in physiological solutions. SDG treatment scavenged

  17. Superconductor coil geometry and ac losses

    NASA Technical Reports Server (NTRS)

    Pierce, T. V., Jr.; Zapata, R. N.

    1976-01-01

    An empirical relation is presented which allows simple computation of volume-averaged winding fields from central fields for coils of small rectangular cross sections. This relation suggests that, in certain applications, ac-loss minimization can be accomplished by use of low winding densities, provided that hysteresis losses are independent of winding density. The ac-loss measurements on coils wound of twisted multifilamentary composite superconductors show no significant dependence on ac losses on winding density, thus permitting the use of winding density as an independent design parameter in loss minimization.

  18. [Reconstruction of tangential and circular infected bone defects].

    PubMed

    Schmidt, H G; Neikes, M; Zimmer, W

    1987-12-01

    In the treatment of bone infections the reconstruction and rehabilitation of bone defects is a problem that often requires treatment secondary to curative treatment of the infection. For the reconstruction of smaller and more extensive defects we used predominantly (92.7%) autogenous (autologous) untreated spongiosa and in only 7% of the cases allogenic (homologous) spongiosa from an organ bank, this being added if necessary. Recently the additionally introduced vascularized bone chip has become a useful extension of the therapy concept. The problems and complications of defect reconstruction are demonstrated for 705 cases of bone infection with 472 defects of different sizes, based on a comprehensive classification with defect calculation. Surgical technical approach and special aspects of after-treatment are described, as well as the results for every group of cases. We achieved stability and freedom from infection in a total of 93.7% of the patients. As was to be expected, the problems grow with the size of the defect. Particularly problematic are joint infections with adjacent extensive circular defect.

  19. Reconstruction From Multiple Particles for 3D Isotropic Resolution in Fluorescence Microscopy.

    PubMed

    Fortun, Denis; Guichard, Paul; Hamel, Virginie; Sorzano, Carlos Oscar S; Banterle, Niccolo; Gonczy, Pierre; Unser, Michael

    2018-05-01

    The imaging of proteins within macromolecular complexes has been limited by the low axial resolution of optical microscopes. To overcome this problem, we propose a novel computational reconstruction method that yields isotropic resolution in fluorescence imaging. The guiding principle is to reconstruct a single volume from the observations of multiple rotated particles. Our new operational framework detects particles, estimates their orientation, and reconstructs the final volume. The main challenge comes from the absence of initial template and a priori knowledge about the orientations. We formulate the estimation as a blind inverse problem, and propose a block-coordinate stochastic approach to solve the associated non-convex optimization problem. The reconstruction is performed jointly in multiple channels. We demonstrate that our method is able to reconstruct volumes with 3D isotropic resolution on simulated data. We also perform isotropic reconstructions from real experimental data of doubly labeled purified human centrioles. Our approach revealed the precise localization of the centriolar protein Cep63 around the centriole microtubule barrel. Overall, our method offers new perspectives for applications in biology that require the isotropic mapping of proteins within macromolecular assemblies.

  20. Edge-oriented dual-dictionary guided enrichment (EDGE) for MRI-CT image reconstruction.

    PubMed

    Li, Liang; Wang, Bigong; Wang, Ge

    2016-01-01

    In this paper, we formulate the joint/simultaneous X-ray CT and MRI image reconstruction. In particular, a novel algorithm is proposed for MRI image reconstruction from highly under-sampled MRI data and CT images. It consists of two steps. First, a training dataset is generated from a series of well-registered MRI and CT images on the same patients. Then, an initial MRI image of a patient can be reconstructed via edge-oriented dual-dictionary guided enrichment (EDGE) based on the training dataset and a CT image of the patient. Second, an MRI image is reconstructed using the dictionary learning (DL) algorithm from highly under-sampled k-space data and the initial MRI image. Our algorithm can establish a one-to-one correspondence between the two imaging modalities, and obtain a good initial MRI estimation. Both noise-free and noisy simulation studies were performed to evaluate and validate the proposed algorithm. The results with different under-sampling factors show that the proposed algorithm performed significantly better than those reconstructed using the DL algorithm from MRI data alone.

  1. Effects of Wii balance board exercises on balance after posterior cruciate ligament reconstruction.

    PubMed

    Puh, Urška; Majcen, Nia; Hlebš, Sonja; Rugelj, Darja

    2014-05-01

    To establish the effects of training on Wii balance board (WBB) after posterior cruciate ligament (PCL) reconstruction on balance. Included patient injured her posterior cruciate ligament 22 months prior to the study. Training on WBB was performed 4 weeks, 6 times per week, 30-45 min per day. Center of pressure (CoP) sway during parallel and one-leg stance, and body weight distribution in parallel stance were measured. Additionally, measurements of joint range of motion and limb circumferences were taken before and after training. After training, the body weight was almost equally distributed on both legs. Decrease in CoP sway was most significant for one-leg stance with each leg on compliant surface with eyes open and closed. The knee joint range of motion increased and limb circumferences decreased. According to the results of this single case report, we might recommend the use of WBB for balance training after PCL reconstruction. Case series with no comparison group, Level IV.

  2. Fibular free flap reconstruction for the management of advanced bilateral mandibular osteoradionecrosis.

    PubMed

    Shan, Xiao-Feng; Li, Ru-Huang; Lu, Xu-Guang; Cai, Zhi-Gang; Zhang, Jie; Zhang, Jian-Guo

    2015-03-01

    Fibular osteoseptocutaneous flap has been widely used for unilateral mandibular reconstruction. However, reports about the effects of fibular osteoseptocutaneous flap for the reconstruction of bilateral mandibular defects are limited. In this study, we used free vascularized fibular flaps to successfully manage bilateral mandibular osteoradionecrosis(ORN) in 5 patients. Functional aspects were evaluated during the reconstruction process. All 5 patients had bilateral refractory ORN of the mandible and underwent radical resection between 2003 and 2011. The reconstruction surgery was performed in 2 stages using 2 free fibular flaps in 3 patients. In the other 2 patients, reconstruction was performed in a single stage using 2 separate flaps prepared from a single fibula. All patients had a healthy mandibular symphysis and meniscus of the temporomandibular joint, and these structures were preserved during the reconstruction.Of the 10 defects involving the mandible sides, 9 were successfully reconstructed. One microvascular composite flap failed because of radiation injury to the arterial endothelium at the recipient site. After the treatments, all patients had good esthetic and functional outcomes. Preoperative clinical features such as trismus and dysphagia were also markedly improved. Our surgical method may be an effective alternative for the clinical management of advanced bilateral mandibular ORN.

  3. DC-biased AC-electroosmotic and AC-electrothermal flow mixing in microchannels.

    PubMed

    Ng, Wee Yang; Goh, Shireen; Lam, Yee Cheong; Yang, Chun; Rodríguez, Isabel

    2009-03-21

    This paper presents a novel approach of mixing two laminar flowing streams in microchannels. The mixer consists of a pair of electrodes disposed along a fluidic channel. By energizing the electrodes with a DC-biased (2.5 V) AC voltage (20 Vpp), an electrokinetic flow is induced with a flow profile perpendicular to that of the incoming laminar streams of liquids to be mixed. As a result, the flow lines of the incoming streams and the induced flow are forced to crossover and very efficient stirring and mixing at short mixing length can be achieved. The mixer can be operated from the AC-electroosmotic (ACEO) (sigma=1 mS/m, f=100 kHz) to the AC-electrothermal (ACET) (sigma=500 mS/m, f=500 kHz) flow regimes. The mixing efficiency in the ACEO regime was 92%, with a mixing length of 600 microm (Q=2 microL/min), an estimated mixing time of 69 ms and an induced ACEO flow velocity of approximately 725 microm/s. The mixing efficiency in the ACET regime was 65% for a mixing length of approximately 1200 microm. The mixer is efficient and suitable for mixing reagents in a fluid media from low to high conductivity as required in diverse microfluidic applications.

  4. Lateral patellar retinaculum reconstruction for medial patellar instability following lateral retinacular release: a case report.

    PubMed

    Udagawa, Kazuhiko; Niki, Yasuo; Matsumoto, Hiroaki; Matsumoto, Hideo; Enomoto, Hiroyuki; Toyama, Yoshiaki; Suda, Yasunori

    2014-01-01

    Lateral retinacular release is still being performed in patients with recurrent patellar dislocation as an additional procedure with distal realignment or medial patellofemoral ligament (MPFL) reconstruction. However, consensus remains lacking regarding suitable indications for lateral retinacular release. A 20-year-old woman presented with patellar instability in both medial and lateral directions after undergoing lateral retinacular release with MPFL reconstruction. She displayed inherent systemic joint laxity meeting all seven Carter-Wilkinson criteria. Simultaneous MPFL revision and lateral retinaculum reconstruction successfully improved patellar instability in both directions. This case provides an example of iatrogenic medial patellar instability after failed lateral retinacular release. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. ULNAR NERVE COMPONENT TO INNERVATION OF THUMB CARPOMETACARPAL JOINT

    PubMed Central

    Miki, Roberto Augusto; Kam, Check C; Gennis, Elisabeth R; Barkin, Jodie A; Riel, Ryan U; Robinson, Philip G; Owens, Patrick W

    2011-01-01

    Purpose Thumb carpometacarpal (CMC) joint arthritis is one of the most common problems addressed by hand surgeons. The gold standard of treatment for thumb CMC joint arthritis is trapeziectomy, ligament reconstruction and tendon interposition. Denervation of the thumb CMC joint is not currently used to treat arthritis in this joint due to the failure of the procedure to yield significant symptomatic relief. The failure of denervation is puzzling, given that past anatomic studies show the radial nerve is the major innervation of the thumb CMC joint with the lateral antebrachial nerve and the median nerve also innervating this joint. Although no anatomic study has ever shown that the ulnar nerve innervates the CMC joint, due to both the failure of denervation and the success of arthroscopic thermal ablation, we suspect that previous anatomic studies may have overlooked innervation of the thumb CMC joint via the ulnar nerve. Methods We dissected 19 formalin-preserved cadaveric hand-to-mid-forearm specimens. The radial, median and ulnar nerves were identified in the proximal forearm and then followed distally. Any branch heading toward the radial side of the hand were followed to see if they innervated the thumb CMC joint. Results Eleven specimens (58%) had superficial radial nerve innervation to the thumb CMC joint. Nine specimens (47%) had median nerve innervation from the motor branch. Nine specimens (47%) had ulnar nerve innervation from the motor branch. Conclusions We believe this is the first study to demonstrate that the ulnar nerve innervates the thumb CMC joint This finding may explain the poor results seen in earlier attempts at denervation of the thumb CMC, but the more favorable results with techniques such as arthroscopy with thermal ablation. PMID:22096446

  6. Use of an AC induction motor system for producing finger movements in human subjects.

    PubMed

    Proudlock, F A; Scott, J J

    1998-12-01

    This report describes the set-up and evaluation of a novel system for producing precise finger movements, for tests of movement perception. The specifications were to construct a system using commercially available components that were easy to use but which offered both flexibility and also high precision control. The system was constructed around an industrial AC induction motor with an optical encoder, controlled by an AC servo digital control module that could be programmed using a simple, high-level language. This set-up fulfilled the requirements regarding position and velocity control for a range of movements and also the facility for the subject to move the joint voluntarily while still attached to the motor. However a number of problems were encountered, the most serious being the level of vibration and the inability to vary the torque during movements. The vibration was reduced to the point where it did not affect the subject, by the introduction of mechanical dampening using an anti-vibration coupling and a pneumatic splint. The torque control could not be modified during rotation and so the system could only be operated using constant torque for any given movement.

  7. [Pigmented villonodular synovitis of the temporo mandibular joint. Differential diagnosis and therapy].

    PubMed

    Kunz, C; Leiggener, C S; Fridrich, K; Schmuziger, N; Hammer, B

    2003-07-01

    For the temporomandibular joint (TMJ), functional disorders are common but tumors and tumor like lesions are rare, although these are often mistaken for functional ailments. Early examination by computed tomography or, as a method of choice, magnetic resonance imaging is recommended in case of persisting TMJ problems. Pigmented villonodular synovitis (PVNS) is a rare benign but locally destructive fibrohistiocytic lesion originating in synovial tissue. Involvement of the temporomandibular joint is extremely rare, with the average age of patients being 44.6 years. This paper reports on a 13-year-old patient with diffuse PVNS involving the middle ear and middle cranial fossa. The treatment of choice involves wide local excision and reconstruction of the temporomandibular joint with long-term follow-up. Pathogenesis and differential diagnosis are discussed.

  8. Coupling reconstruction and motion estimation for dynamic MRI through optical flow constraint

    NASA Astrophysics Data System (ADS)

    Zhao, Ningning; O'Connor, Daniel; Gu, Wenbo; Ruan, Dan; Basarab, Adrian; Sheng, Ke

    2018-03-01

    This paper addresses the problem of dynamic magnetic resonance image (DMRI) reconstruction and motion estimation jointly. Because of the inherent anatomical movements in DMRI acquisition, reconstruction of DMRI using motion estimation/compensation (ME/MC) has been explored under the compressed sensing (CS) scheme. In this paper, by embedding the intensity based optical flow (OF) constraint into the traditional CS scheme, we are able to couple the DMRI reconstruction and motion vector estimation. Moreover, the OF constraint is employed in a specific coarse resolution scale in order to reduce the computational complexity. The resulting optimization problem is then solved using a primal-dual algorithm due to its efficiency when dealing with nondifferentiable problems. Experiments on highly accelerated dynamic cardiac MRI with multiple receiver coils validate the performance of the proposed algorithm.

  9. Geomechanical Response of Jointed Caprock During CO2 Geological Sequestration

    NASA Astrophysics Data System (ADS)

    Newell, P.; Martinez, M. J.; Bishop, J. E.

    2014-12-01

    Geological sequestration of CO2 refers to the injection of supercritical CO2 into deep reservoirs trapped beneath a low-permeability caprock formation. Maintaining caprock integrity during the injection process is the most important factor for a successful injection. In this work we evaluate the potential for jointed caprock during injection scenarios using coupled three-dimensional multiphase flow and geomechanics modeling. Evaluation of jointed/fractured caprock systems is of particular concern to CO2 sequestration because creation or reactivation of joints (mechanical damage) can lead to enhanced pathways for leakage. In this work, we use an equivalent continuum approach to account for the joints within the caprock. Joint's aperture and non-linear stiffness of the caprock will be updated dynamically based on the effective normal stress. Effective permeability field will be updated based on the joints' aperture creating an anisotropic permeability field throughout the caprock. This feature would add another coupling between the solid and fluid in addition to basic Terzaghi's effective stress concept. In this study, we evaluate the impact of the joint's orientation and geometry of caprock and reservoir layers on geomechanical response of the CO2 geological systems. This work is supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  10. Rotator Cuff Deficient Arthritis of the Glenohumeral Joint

    PubMed Central

    Macaulay, Alec A.; Greiwe, R. Michael

    2010-01-01

    Rotator cuff deficient arthritis of the glenohumeral joint, especially cuff tear arthropathy, has proved a challenging clinical entity for orthopaedic surgeons ever since Charles Neer originally detailed the problem in 1983. Understanding has improved regarding the pathophysiology and pathomechanics underlying cuff tear arthropathy. Surgical reconstruction options can lead to excellent outcomes for patients afflicted with these painful and functionally limited shoulders. Humeral hemiarthroplasty and reverse total shoulder arthroplasty have jumped to the forefront in the treatment of cuff tear arthropathy. As studies continue to look at the results of these procedures in cuff tear arthropathy, existing indications and treatment algorithms will be further refined. In this article the history and pathophysiology of cuff tear arthropathy are reviewed. Additionally, the clinical findings and results of surgical reconstruction are discussed. PMID:21119934

  11. Spectroscopic Determination of the AC Voltammetric Response.

    DTIC Science & Technology

    1984-01-06

    characterization of electrode processes. More recently, with the advent of linear sweep cyclic AC voltanmetry(12’ 13), it has been shown that AC methods...implemented with the same instrumentation ( 7 ) as previously used in MSRS and retains both the qualitative and quantitative utility of linear sweep ...voltammetric response (eg. peak width at balf-height, peak separation and cross-over potential in cyclic AC voltametry ) apply equally well to the SACRS

  12. Joint DIII-D/EAST Experiments Toward Steady State AT Demonstration

    NASA Astrophysics Data System (ADS)

    Garofalo, A. M.; Meneghini, O.; Staebler, G. M.; van Zeeland, M. A.; Gong, X.; Ding, S.; Qian, J.; Ren, Q.; Xu, G.; Grierson, B. A.; Solomon, W. M.; Holcomb, C. T.

    2015-11-01

    Joint DIII-D/EAST experiments on fully noninductive operation at high poloidal beta have demonstrated several attractive features of this regime for a steady-state fusion reactor. Very large bootstrap fraction (>80 %) is desirable because it reduces the demands on external noninductive current drive. High bootstrap fraction with an H-mode edge results in a broad current profile and internal transport barriers (ITBs) at large minor radius, leading to high normalized energy confinement and high MHD stability limits. The ITB radius expands with higher normalized beta, further improving both stability and confinement. Electron density ITB and large Shafranov shift lead to low AE activity in the plasma core and low anomalous fast ion losses. Both the ITB and the current profile show remarkable robustness against perturbations, without external control. Supported by US DOE under DE-FC02-04ER54698, DE-AC02-09CH11466 & DE-AC52-07NA27344 & by NMCFSP under contracts 2015GB102000 and 2015GB110001.

  13. THERMIONIC AC GENERATION

    DTIC Science & Technology

    is shown that the maximum ac efficiency is equal to approximately 70% of the corresponding dc value. An illustrative example, including a proposed design for a rather unconventional transformer, is appended. (Author)

  14. 78 FR 49318 - Availability of Draft Advisory Circular (AC) 90-106A and AC 20-167A

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-13

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration [Docket No FAA-2013-0485] Availability of Draft Advisory Circular (AC) 90-106A and AC 20- 167A AGENCY: Federal Aviation Administration..., Federal Aviation Administration, 800 Independence Avenue SW., Washington, DC 20591; telephone (202) 385...

  15. Optimization-Based Approach for Joint X-Ray Fluorescence and Transmission Tomographic Inversion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Di, Zichao; Leyffer, Sven; Wild, Stefan M.

    2016-01-01

    Fluorescence tomographic reconstruction, based on the detection of photons coming from fluorescent emission, can be used for revealing the internal elemental composition of a sample. On the other hand, conventional X-ray transmission tomography can be used for reconstructing the spatial distribution of the absorption coefficient inside a sample. In this work, we integrate both X-ray fluorescence and X-ray transmission data modalities and formulate a nonlinear optimization-based approach for reconstruction of the elemental composition of a given object. This model provides a simultaneous reconstruction of both the quantitative spatial distribution of all elements and the absorption effect in the sample. Mathematicallymore » speaking, we show that compared with the single-modality inversion (i.e., the X-ray transmission or fluorescence alone), the joint inversion provides a better-posed problem, which implies a better recovery. Therefore, the challenges in X-ray fluorescence tomography arising mainly from the effects of self-absorption in the sample are partially mitigated. The use of this technique is demonstrated on the reconstruction of several synthetic samples.« less

  16. Isokinetic Testing in Evaluation Rehabilitation Outcome After ACL Reconstruction

    PubMed Central

    Cvjetkovic, Dragana Dragicevic; Bijeljac, Sinisa; Palija, Stanislav; Talic, Goran; Radulovic, Tatjana Nozica; Kosanovic, Milkica Glogovac; Manojlovic, Slavko

    2015-01-01

    Introduction: Numerous rehab protocols have been used in rehabilitation after ACL reconstruction. Isokinetic testing is an objective way to evaluate dynamic stability of the knee joint that estimates the quality of rehabilitation outcome after ACL reconstruction. Our investigation goal was to show importance of isokinetic testing in evaluation thigh muscle strength in patients which underwent ACL reconstruction and rehabilitation protocol. Subjects and methods: In prospective study, we evaluated 40 subjects which were divided into two groups. Experimental group consisted of 20 recreational males which underwent ACL reconstruction with hamstring tendon and rehabilitation protocol 6 months before isokinetic testing. Control group (20 subjects) consisted of healthy recreational males. In all subjects knee muscle testing was performed on a Biodex System 4 Pro isokinetic dynamo-meter et velocities of 60°/s and 180°/s. We followed average peak torque to body weight (PT/BW) and classic H/Q ratio. In statistical analysis Student’s T test was used. Results: There were statistically significant differences between groups in all evaluated parameters except of the mean value of PT/BW of the quadriceps et velocity of 60°/s (p>0.05). Conclusion: Isokinetic testing of dynamic stabilizers of the knee is need in diagnostic and treatment thigh muscle imbalance. We believe that isokinetic testing is an objective parameter for return to sport activities after ACL reconstruction. PMID:25870471

  17. Isokinetic Testing in Evaluation Rehabilitation Outcome After ACL Reconstruction.

    PubMed

    Cvjetkovic, Dragana Dragicevic; Bijeljac, Sinisa; Palija, Stanislav; Talic, Goran; Radulovic, Tatjana Nozica; Kosanovic, Milkica Glogovac; Manojlovic, Slavko

    2015-02-01

    Numerous rehab protocols have been used in rehabilitation after ACL reconstruction. Isokinetic testing is an objective way to evaluate dynamic stability of the knee joint that estimates the quality of rehabilitation outcome after ACL reconstruction. Our investigation goal was to show importance of isokinetic testing in evaluation thigh muscle strength in patients which underwent ACL reconstruction and rehabilitation protocol. In prospective study, we evaluated 40 subjects which were divided into two groups. Experimental group consisted of 20 recreational males which underwent ACL reconstruction with hamstring tendon and rehabilitation protocol 6 months before isokinetic testing. Control group (20 subjects) consisted of healthy recreational males. In all subjects knee muscle testing was performed on a Biodex System 4 Pro isokinetic dynamo-meter et velocities of 60°/s and 180°/s. We followed average peak torque to body weight (PT/BW) and classic H/Q ratio. In statistical analysis Student's T test was used. There were statistically significant differences between groups in all evaluated parameters except of the mean value of PT/BW of the quadriceps et velocity of 60°/s (p>0.05). Isokinetic testing of dynamic stabilizers of the knee is need in diagnostic and treatment thigh muscle imbalance. We believe that isokinetic testing is an objective parameter for return to sport activities after ACL reconstruction.

  18. Reconstruction of radial thermal conductivity depth profile in case hardened steel rods

    NASA Astrophysics Data System (ADS)

    Celorrio, Ricardo; Mendioroz, Arantza; Apiñaniz, Estibaliz; Salazar, Agustín; Wang, Chinhua; Mandelis, Andreas

    2009-04-01

    In this work the surface thermal-wave field (ac temperature) of a solid cylinder illuminated by a modulated light beam is calculated first in two cases: a multilayered cylinder and a cylinder the radial thermal conductivity of which varies continuously. It is demonstrated numerically that, using a few layers of different thicknesses, the surface thermal-wave field of a cylindrical sample with continuously varying radial thermal conductivity can be calculated with high accuracy. Next, an inverse procedure based on the multilayered model is used to reconstruct the radial thermal conductivity profile of hardened C1018 steel rods, the surface temperature of which was measured by photothermal radiometry. The reconstructed thermal conductivity depth profile has a similar shape to those found for flat samples of this material and shows a qualitative anticorrelation with the hardness depth profile.

  19. Differential Roles of AC2 and AC4 of Cassava Geminiviruses in Mediating Synergism and Suppression of Posttranscriptional Gene Silencing

    PubMed Central

    Vanitharani, Ramachandran; Chellappan, Padmanabhan; Pita, Justin S.; Fauquet, Claude M.

    2004-01-01

    Posttranscriptional gene silencing (PTGS) in plants is a natural defense mechanism against virus infection. In mixed infections, virus synergism is proposed to result from suppression of the host defense mechanism by the viruses. Synergistic severe mosaic disease caused by simultaneous infection with isolates of the Cameroon strain of African cassava mosaic virus (ACMV-[CM]) and East African cassava mosaic Cameroon virus (EACMCV) in cassava and tobacco is characterized by a dramatic increase in symptom severity and a severalfold increase in viral-DNA accumulation by both viruses compared to that in singly infected plants. Here, we report that synergism between ACMV-[CM] and EACMCV is a two-way process, as the presence of the DNA-A component of ACMV-[CM] or EACMCV in trans enhanced the accumulation of viral DNA of EACMCV and ACMV-[CM], respectively, in tobacco BY-2 protoplasts. Furthermore, transient expression of ACMV-[CM] AC4 driven by the Cauliflower mosaic virus 35S promoter (p35S-AC4) enhanced EACMCV DNA accumulation by ∼8-fold in protoplasts, while p35S-AC2 of EACMCV enhanced ACMV-[CM] DNA accumulation, also by ∼8-fold. An Agrobacterium-based leaf infiltration assay determined that ACMV-[CM] AC4 and EACMCV AC2, the putative synergistic genes, were able to suppress PTGS induced by green fluorescent protein (GFP) and eliminated the short interfering RNAs associated with PTGS, with a correlated increase in GFP mRNA accumulation. In addition, we have identified AC4 of Sri Lankan cassava mosaic virus and AC2 of Indian cassava mosaic virus as suppressors of PTGS, indicating that geminiviruses evolved differently in regard to interaction with the host. The specific and different roles played by these AC2 and AC4 proteins of cassava geminiviruses in regulating anti-PTGS activity and their relation to synergism are discussed. PMID:15308741

  20. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered medical examination light. 880.6320... Miscellaneous Devices § 880.6320 AC-powered medical examination light. (a) Identification. An AC-powered medical examination light is an AC-powered device intended for medical purposes that is used to illuminate body...

  1. Joint SSRTNet/ALS-MES Workshop report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shuh, David; Van Hove, Michel

    2001-11-30

    This joint workshop brought together experimentalists and theorists interested in synchrotron radiation and highlighted subjects relevant to molecular environmental science (MES). The strong mutual interest between the participants resulted in joint sessions on the first day, followed by more specialized parallel sessions on the second day. Held in conjunction with the Advanced Light Source (ALS) Users' Association Annual Meeting at the Lawrence Berkeley National Laboratory (Berkeley Lab), the Synchrotron Radiation Research Theory Network (SRRTNet) workshop was co-organized by Michel Van Hove (Berkeley Lab and University of California, Davis) and Andrew Canning (Berkeley Lab), while David Shuh (Berkeley Lab) organized themore » ALS-MES workshop. SRRTNet is a global network that promotes the interaction of theory and experiment (http://www.cse.clrc.ac.uk/Activity/SRRTnet). The ALS-MES project is constructing Beamline 11.0.2.1-2, a new soft x-ray beamline for MES investigations at photon energies from 75 eV to 2 keV, to provide photons for wet spectroscopy end stations and an upgraded scanning transmission x-ray microscope (STXM). The ALS-MES beamline and end stations will be available for users in the late fall of 2002.« less

  2. High-frequency ac power distribution in Space Station

    NASA Technical Reports Server (NTRS)

    Tsai, Fu-Sheng; Lee, Fred C. Y.

    1990-01-01

    A utility-type 20-kHz ac power distribution system for the Space Station, employing resonant power-conversion techniques, is presented. The system converts raw dc voltage from photovoltaic cells or three-phase LF ac voltage from a solar dynamic generator into a regulated 20-kHz ac voltage for distribution among various loads. The results of EASY5 computer simulations of the local and global performance show that the system has fast response and good transient behavior. The ac bus voltage is effectively regulated using the phase-control scheme, which is demonstrated with both line and load variations. The feasibility of paralleling the driver-module outputs is illustrated with the driver modules synchronized and sharing a common feedback loop. An HF sinusoidal ac voltage is generated in the three-phase ac input case, when the driver modules are phased 120 deg away from one another and their outputs are connected in series.

  3. An electron tomography algorithm for reconstructing 3D morphology using surface tangents of projected scattering interfaces

    NASA Astrophysics Data System (ADS)

    Petersen, T. C.; Ringer, S. P.

    2010-03-01

    Upon discerning the mere shape of an imaged object, as portrayed by projected perimeters, the full three-dimensional scattering density may not be of particular interest. In this situation considerable simplifications to the reconstruction problem are possible, allowing calculations based upon geometric principles. Here we describe and provide an algorithm which reconstructs the three-dimensional morphology of specimens from tilt series of images for application to electron tomography. Our algorithm uses a differential approach to infer the intersection of projected tangent lines with surfaces which define boundaries between regions of different scattering densities within and around the perimeters of specimens. Details of the algorithm implementation are given and explained using reconstruction calculations from simulations, which are built into the code. An experimental application of the algorithm to a nano-sized Aluminium tip is also presented to demonstrate practical analysis for a real specimen. Program summaryProgram title: STOMO version 1.0 Catalogue identifier: AEFS_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFS_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 2988 No. of bytes in distributed program, including test data, etc.: 191 605 Distribution format: tar.gz Programming language: C/C++ Computer: PC Operating system: Windows XP RAM: Depends upon the size of experimental data as input, ranging from 200 Mb to 1.5 Gb Supplementary material: Sample output files, for the test run provided, are available. Classification: 7.4, 14 External routines: Dev-C++ ( http://www.bloodshed.net/devcpp.html) Nature of problem: Electron tomography of specimens for which conventional back projection may fail and/or data for which there is a limited angular

  4. Improving outcomes following reconstruction of pressure sores in spinal injury patients: A multidisciplinary approach.

    PubMed

    Tadiparthi, S; Hartley, A; Alzweri, L; Mecci, M; Siddiqui, H

    2016-07-01

    Pressure sore treatment in spinal injury patients is challenging. A multidisciplinary approach with joint management by the plastic surgery and spinal injury teams was initiated at our institution in 2005 to improve patient care and surgical outcomes following reconstruction. This study assessed the surgical outcomes following reconstruction using the team approach and to compare inpatient stay and readmissions for complications before and after the multidisciplinary protocol was introduced. A retrospective review of consecutive patients in the multidisciplinary pressure sore clinic was performed. Data were collected on patient demographics, reconstructive techniques, surgical outcomes and readmission for any complications. In total, 45 patients with 60 pressure sores (grade 3 or 4) were reviewed in the joint clinic between 2005 and 2011. The majority of patients were paraplegic (78%), while the remaining 22% were tetraplegic. Ischial sores were the most common (45%) followed by trochanteric (23%) and sacral (20%) sores. Multiple sores were noted in 44% of patients. Flap reconstruction was required in 32 patients (71%); after a mean follow-up time of 33 months (range 25-72 months), there were three (9%) major complications (two recurrences of pressure sores and one sinus) and seven (22%) minor complications. After introduction of patient care pathways through the multidisciplinary approach, the rate of readmission for complications decreased from 14% to 5.5% and inpatient stay upon readmission reduced from 65 to 45 days. Implementation of a multidisciplinary approach was key to optimising surgical outcomes, achieving a low recurrence rate (6%) and reducing readmissions. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  5. Evaluation of reconstruction errors and identification of artefacts for JET gamma and neutron tomography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Craciunescu, Teddy, E-mail: teddy.craciunescu@jet.uk; Tiseanu, Ion; Zoita, Vasile

    The Joint European Torus (JET) neutron profile monitor ensures 2D coverage of the gamma and neutron emissive region that enables tomographic reconstruction. Due to the availability of only two projection angles and to the coarse sampling, tomographic inversion is a limited data set problem. Several techniques have been developed for tomographic reconstruction of the 2-D gamma and neutron emissivity on JET, but the problem of evaluating the errors associated with the reconstructed emissivity profile is still open. The reconstruction technique based on the maximum likelihood principle, that proved already to be a powerful tool for JET tomography, has been usedmore » to develop a method for the numerical evaluation of the statistical properties of the uncertainties in gamma and neutron emissivity reconstructions. The image covariance calculation takes into account the additional techniques introduced in the reconstruction process for tackling with the limited data set (projection resampling, smoothness regularization depending on magnetic field). The method has been validated by numerically simulations and applied to JET data. Different sources of artefacts that may significantly influence the quality of reconstructions and the accuracy of variance calculation have been identified.« less

  6. Transcranial Alternating Current Stimulation (tACS) Mechanisms and Protocols

    PubMed Central

    Tavakoli, Amir V.; Yun, Kyongsik

    2017-01-01

    Perception, cognition and consciousness can be modulated as a function of oscillating neural activity, while ongoing neuronal dynamics are influenced by synaptic activity and membrane potential. Consequently, transcranial alternating current stimulation (tACS) may be used for neurological intervention. The advantageous features of tACS include the biphasic and sinusoidal tACS currents, the ability to entrain large neuronal populations, and subtle control over somatic effects. Through neuromodulation of phasic, neural activity, tACS is a powerful tool to investigate the neural correlates of cognition. The rapid development in this area requires clarity about best practices. Here we briefly introduce tACS and review the most compelling findings in the literature to provide a starting point for using tACS. We suggest that tACS protocols be based on functional brain mechanisms and appropriate control experiments, including active sham and condition blinding. PMID:28928634

  7. Brain extraction from normal and pathological images: A joint PCA/Image-Reconstruction approach.

    PubMed

    Han, Xu; Kwitt, Roland; Aylward, Stephen; Bakas, Spyridon; Menze, Bjoern; Asturias, Alexander; Vespa, Paul; Van Horn, John; Niethammer, Marc

    2018-08-01

    Brain extraction from 3D medical images is a common pre-processing step. A variety of approaches exist, but they are frequently only designed to perform brain extraction from images without strong pathologies. Extracting the brain from images exhibiting strong pathologies, for example, the presence of a brain tumor or of a traumatic brain injury (TBI), is challenging. In such cases, tissue appearance may substantially deviate from normal tissue appearance and hence violates algorithmic assumptions for standard approaches to brain extraction; consequently, the brain may not be correctly extracted. This paper proposes a brain extraction approach which can explicitly account for pathologies by jointly modeling normal tissue appearance and pathologies. Specifically, our model uses a three-part image decomposition: (1) normal tissue appearance is captured by principal component analysis (PCA), (2) pathologies are captured via a total variation term, and (3) the skull and surrounding tissue is captured by a sparsity term. Due to its convexity, the resulting decomposition model allows for efficient optimization. Decomposition and image registration steps are alternated to allow statistical modeling of normal tissue appearance in a fixed atlas coordinate system. As a beneficial side effect, the decomposition model allows for the identification of potentially pathological areas and the reconstruction of a quasi-normal image in atlas space. We demonstrate the effectiveness of our approach on four datasets: the publicly available IBSR and LPBA40 datasets which show normal image appearance, the BRATS dataset containing images with brain tumors, and a dataset containing clinical TBI images. We compare the performance with other popular brain extraction models: ROBEX, BEaST, MASS, BET, BSE and a recently proposed deep learning approach. Our model performs better than these competing approaches on all four datasets. Specifically, our model achieves the best median (97.11) and

  8. Reconstruction of bilateral tibial aplasia and split hand-foot syndrome in a father and daughter.

    PubMed

    Al Kaissi, Ali; Ganger, Rudolf; Klaushofer, Klaus; Grill, Franz

    2014-01-01

    Tibial aplasia is of heterogeneous aetiology, the majority of reports are sporadic. We describe the reconstruction procedures in two subjects - a daughter and father manifested autosomal dominant (AD) inheritance of the bilateral tibial aplasia and split hand-foot syndrome. Reconstruction of these patients required multiple surgical procedures and orthoprosthesis was mandatory. The main goal of treatment was to achieve walking. Stabilization of the ankle joint by fibular-talar-chondrodesis on both sides, followed by bilateral Brown-procedure at the knee joint level has been applied accordingly. The outcome was with improved function of the deformed limbs and walking was achieved with simultaneous designation of orthotic fitting. This is the first study encompassing the diagnosis and management of a father and daughter with bilateral tibial aplasia associated with variable split hand/foot deformity without foot ablation. Our patients showed the typical AD pattern of inheritance of split-hand/foot and tibial aplasia.

  9. Long-term interventions effects of robotic training on patients after anterior cruciate ligament reconstruction.

    PubMed

    Hu, Chunying; Huang, Qiuchen; Yu, Lili; Zhou, Yue; Gu, Rui; Ye, Miao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

    2016-08-01

    [Purpose] The aim of this study was to examine the long-term interventions effects of robot-assisted therapy rehabilitation on functional activity levels after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 8 patients (6 males and 2 females) who received anterior cruciate ligament reconstruction. The subjects participated in robot-assisted therapy lasting for one month. The Timed Up-and-Go test, 10-Meter Walk test, Functional Reach Test, surface electromyography of the vastus lateralis and vastus medialis, and extensor strength of isokinetic movement of the knee joint were evaluated before and after the intervention. [Results] The average value of the of vastus medialis EMG, Functional Reach Test, and the maximum and average extensor strength of the knee joint isokinetic movement increased significantly, and the time of the 10-Meter Walk test decreased significantly. [Conclusion] These results suggest that walking ability and muscle strength can be improved by robotic walking training as a long-term intervention.

  10. Long-term interventions effects of robotic training on patients after anterior cruciate ligament reconstruction

    PubMed Central

    Hu, Chunying; Huang, Qiuchen; Yu, Lili; Zhou, Yue; Gu, Rui; Ye, Miao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

    2016-01-01

    [Purpose] The aim of this study was to examine the long-term interventions effects of robot-assisted therapy rehabilitation on functional activity levels after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 8 patients (6 males and 2 females) who received anterior cruciate ligament reconstruction. The subjects participated in robot-assisted therapy lasting for one month. The Timed Up-and-Go test, 10-Meter Walk test, Functional Reach Test, surface electromyography of the vastus lateralis and vastus medialis, and extensor strength of isokinetic movement of the knee joint were evaluated before and after the intervention. [Results] The average value of the of vastus medialis EMG, Functional Reach Test, and the maximum and average extensor strength of the knee joint isokinetic movement increased significantly, and the time of the 10-Meter Walk test decreased significantly. [Conclusion] These results suggest that walking ability and muscle strength can be improved by robotic walking training as a long-term intervention. PMID:27630396

  11. Joint Optimization of Fluence Field Modulation and Regularization in Task-Driven Computed Tomography

    PubMed Central

    Gang, G. J.; Siewerdsen, J. H.; Stayman, J. W.

    2017-01-01

    Purpose This work presents a task-driven joint optimization of fluence field modulation (FFM) and regularization in quadratic penalized-likelihood (PL) reconstruction. Conventional FFM strategies proposed for filtered-backprojection (FBP) are evaluated in the context of PL reconstruction for comparison. Methods We present a task-driven framework that leverages prior knowledge of the patient anatomy and imaging task to identify FFM and regularization. We adopted a maxi-min objective that ensures a minimum level of detectability index (d′) across sample locations in the image volume. The FFM designs were parameterized by 2D Gaussian basis functions to reduce dimensionality of the optimization and basis function coefficients were estimated using the covariance matrix adaptation evolutionary strategy (CMA-ES) algorithm. The FFM was jointly optimized with both space-invariant and spatially-varying regularization strength (β) - the former via an exhaustive search through discrete values and the latter using an alternating optimization where β was exhaustively optimized locally and interpolated to form a spatially-varying map. Results The optimal FFM inverts as β increases, demonstrating the importance of a joint optimization. For the task and object investigated, the optimal FFM assigns more fluence through less attenuating views, counter to conventional FFM schemes proposed for FBP. The maxi-min objective homogenizes detectability throughout the image and achieves a higher minimum detectability than conventional FFM strategies. Conclusions The task-driven FFM designs found in this work are counter to conventional patterns for FBP and yield better performance in terms of the maxi-min objective, suggesting opportunities for improved image quality and/or dose reduction when model-based reconstructions are applied in conjunction with FFM. PMID:28626290

  12. Joint optimization of fluence field modulation and regularization in task-driven computed tomography

    NASA Astrophysics Data System (ADS)

    Gang, G. J.; Siewerdsen, J. H.; Stayman, J. W.

    2017-03-01

    Purpose: This work presents a task-driven joint optimization of fluence field modulation (FFM) and regularization in quadratic penalized-likelihood (PL) reconstruction. Conventional FFM strategies proposed for filtered-backprojection (FBP) are evaluated in the context of PL reconstruction for comparison. Methods: We present a task-driven framework that leverages prior knowledge of the patient anatomy and imaging task to identify FFM and regularization. We adopted a maxi-min objective that ensures a minimum level of detectability index (d') across sample locations in the image volume. The FFM designs were parameterized by 2D Gaussian basis functions to reduce dimensionality of the optimization and basis function coefficients were estimated using the covariance matrix adaptation evolutionary strategy (CMA-ES) algorithm. The FFM was jointly optimized with both space-invariant and spatially-varying regularization strength (β) - the former via an exhaustive search through discrete values and the latter using an alternating optimization where β was exhaustively optimized locally and interpolated to form a spatially-varying map. Results: The optimal FFM inverts as β increases, demonstrating the importance of a joint optimization. For the task and object investigated, the optimal FFM assigns more fluence through less attenuating views, counter to conventional FFM schemes proposed for FBP. The maxi-min objective homogenizes detectability throughout the image and achieves a higher minimum detectability than conventional FFM strategies. Conclusions: The task-driven FFM designs found in this work are counter to conventional patterns for FBP and yield better performance in terms of the maxi-min objective, suggesting opportunities for improved image quality and/or dose reduction when model-based reconstructions are applied in conjunction with FFM.

  13. Joint Optimization of Fluence Field Modulation and Regularization in Task-Driven Computed Tomography.

    PubMed

    Gang, G J; Siewerdsen, J H; Stayman, J W

    2017-02-11

    This work presents a task-driven joint optimization of fluence field modulation (FFM) and regularization in quadratic penalized-likelihood (PL) reconstruction. Conventional FFM strategies proposed for filtered-backprojection (FBP) are evaluated in the context of PL reconstruction for comparison. We present a task-driven framework that leverages prior knowledge of the patient anatomy and imaging task to identify FFM and regularization. We adopted a maxi-min objective that ensures a minimum level of detectability index ( d' ) across sample locations in the image volume. The FFM designs were parameterized by 2D Gaussian basis functions to reduce dimensionality of the optimization and basis function coefficients were estimated using the covariance matrix adaptation evolutionary strategy (CMA-ES) algorithm. The FFM was jointly optimized with both space-invariant and spatially-varying regularization strength ( β ) - the former via an exhaustive search through discrete values and the latter using an alternating optimization where β was exhaustively optimized locally and interpolated to form a spatially-varying map. The optimal FFM inverts as β increases, demonstrating the importance of a joint optimization. For the task and object investigated, the optimal FFM assigns more fluence through less attenuating views, counter to conventional FFM schemes proposed for FBP. The maxi-min objective homogenizes detectability throughout the image and achieves a higher minimum detectability than conventional FFM strategies. The task-driven FFM designs found in this work are counter to conventional patterns for FBP and yield better performance in terms of the maxi-min objective, suggesting opportunities for improved image quality and/or dose reduction when model-based reconstructions are applied in conjunction with FFM.

  14. Challenges and solutions in medically managed ACS in the Asia-Pacific region: expert recommendations from the Asia-Pacific ACS Medical Management Working Group.

    PubMed

    Huo, Yong; Thompson, Peter; Buddhari, Wacin; Ge, Junbo; Harding, Scott; Ramanathan, Letchuman; Reyes, Eugenio; Santoso, Anwar; Tam, Li-Wah; Vijayaraghavan, Govindan; Yeh, Hung-I

    2015-03-15

    Acute coronary syndromes (ACS) remain a leading cause of mortality and morbidity in the Asia-Pacific (APAC) region. International guidelines advocate invasive procedures in all but low-risk ACS patients; however, a high proportion of ACS patients in the APAC region receive solely medical management due to a combination of unique geographical, socioeconomic, and population-specific barriers. The APAC ACS Medical Management Working Group recently convened to discuss the ACS medical management landscape in the APAC region. Local and international ACS guidelines and the global and APAC clinical evidence-base for medical management of ACS were reviewed. Challenges in the provision of optimal care for these patients were identified and broadly categorized into issues related to (1) accessibility/systems of care, (2) risk stratification, (3) education, (4) optimization of pharmacotherapy, and (5) cost/affordability. While ACS guidelines clearly represent a valuable standard of care, the group concluded that these challenges can be best met by establishing cardiac networks and individual hospital models/clinical pathways taking into account local risk factors (including socioeconomic status), affordability and availability of pharmacotherapies/invasive facilities, and the nature of local healthcare systems. Potential solutions central to the optimization of ACS medical management in the APAC region are outlined with specific recommendations. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Infrequent transposition of Ac in lettuce, Lactuca sativa.

    PubMed

    Yang, C H; Ellis, J G; Michelmore, R W

    1993-08-01

    The maize transposable element Activator (Ac) is being used to develop a transposon mutagenesis system in lettuce, Lactuca sativa. Two constructs containing the complete Ac from the waxy-m7 locus of maize were introduced into lettuce and monitored for activity using Southern analysis and PCR amplification of the excision site. No transposition of Ac was detected in over 32 transgenic R1 plants, although these constructs were known to provide frequent transposition in other species. Also, no transposition was observed in later generations. In subsequent experiments, transposition was detected in lettuce calli using constructs that allowed selection for excision events. In these constructs, the neomycin phosphotransferase II gene was interrupted by either Ac or Ds. Excision was detected as the ability of callus to grow on kanamycin. Synthesis of the transposase from the cDNA of Ac expressed from the T-DNA 2' promoter resulted in more frequent excision of Ds than was observed with the wild-type Ac. No excision was observed with Ds in the absence of the transposase. The excision events were confirmed by amplification of the excision site by PCR followed by DNA sequencing. Excision and reintegration were also confirmed by Southern analysis. Ac/Ds is therefore capable of transposition in at least calli of lettuce.

  16. Controversies relating to the management of acromioclavicular joint dislocations.

    PubMed

    Modi, C S; Beazley, J; Zywiel, M G; Lawrence, T M; Veillette, C J H

    2013-12-01

    The aim of this review is to address controversies in the management of dislocations of the acromioclavicular joint. Current evidence suggests that operative rather than non-operative treatment of Rockwood grade III dislocations results in better cosmetic and radiological results, similar functional outcomes and longer time off work. Early surgery results in better functional and radiological outcomes with a reduced risk of infection and loss of reduction compared with delayed surgery. Surgical options include acromioclavicular fixation, coracoclavicular fixation and coracoclavicular ligament reconstruction. Although non-controlled studies report promising results for arthroscopic coracoclavicular fixation, there are no comparative studies with open techniques to draw conclusions about the best surgical approach. Non-rigid coracoclavicular fixation with tendon graft or synthetic materials, or rigid acromioclavicular fixation with a hook plate, is preferable to fixation with coracoclavicular screws owing to significant risks of loosening and breakage. The evidence, although limited, also suggests that anatomical ligament reconstruction with autograft or certain synthetic grafts may have better outcomes than non-anatomical transfer of the coracoacromial ligament. It has been suggested that this is due to better restoration horizontal and vertical stability of the joint. Despite the large number of recently published studies, there remains a lack of high-quality evidence, making it difficult to draw firm conclusions regarding these controversial issues.

  17. Obtaining continuous BrAC/BAC estimates in the field: A hybrid system integrating transdermal alcohol biosensor, Intellidrink smartphone app, and BrAC Estimator software tools.

    PubMed

    Luczak, Susan E; Hawkins, Ashley L; Dai, Zheng; Wichmann, Raphael; Wang, Chunming; Rosen, I Gary

    2018-08-01

    Biosensors have been developed to measure transdermal alcohol concentration (TAC), but converting TAC into interpretable indices of blood/breath alcohol concentration (BAC/BrAC) is difficult because of variations that occur in TAC across individuals, drinking episodes, and devices. We have developed mathematical models and the BrAC Estimator software for calibrating and inverting TAC into quantifiable BrAC estimates (eBrAC). The calibration protocol to determine the individualized parameters for a specific individual wearing a specific device requires a drinking session in which BrAC and TAC measurements are obtained simultaneously. This calibration protocol was originally conducted in the laboratory with breath analyzers used to produce the BrAC data. Here we develop and test an alternative calibration protocol using drinking diary data collected in the field with the smartphone app Intellidrink to produce the BrAC calibration data. We compared BrAC Estimator software results for 11 drinking episodes collected by an expert user when using Intellidrink versus breath analyzer measurements as BrAC calibration data. Inversion phase results indicated the Intellidrink calibration protocol produced similar eBrAC curves and captured peak eBrAC to within 0.0003%, time of peak eBrAC to within 18min, and area under the eBrAC curve to within 0.025% alcohol-hours as the breath analyzer calibration protocol. This study provides evidence that drinking diary data can be used in place of breath analyzer data in the BrAC Estimator software calibration procedure, which can reduce participant and researcher burden and expand the potential software user pool beyond researchers studying participants who can drink in the laboratory. Copyright © 2017. Published by Elsevier Ltd.

  18. Calibrationless parallel magnetic resonance imaging: a joint sparsity model.

    PubMed

    Majumdar, Angshul; Chaudhury, Kunal Narayan; Ward, Rabab

    2013-12-05

    State-of-the-art parallel MRI techniques either explicitly or implicitly require certain parameters to be estimated, e.g., the sensitivity map for SENSE, SMASH and interpolation weights for GRAPPA, SPIRiT. Thus all these techniques are sensitive to the calibration (parameter estimation) stage. In this work, we have proposed a parallel MRI technique that does not require any calibration but yields reconstruction results that are at par with (or even better than) state-of-the-art methods in parallel MRI. Our proposed method required solving non-convex analysis and synthesis prior joint-sparsity problems. This work also derives the algorithms for solving them. Experimental validation was carried out on two datasets-eight channel brain and eight channel Shepp-Logan phantom. Two sampling methods were used-Variable Density Random sampling and non-Cartesian Radial sampling. For the brain data, acceleration factor of 4 was used and for the other an acceleration factor of 6 was used. The reconstruction results were quantitatively evaluated based on the Normalised Mean Squared Error between the reconstructed image and the originals. The qualitative evaluation was based on the actual reconstructed images. We compared our work with four state-of-the-art parallel imaging techniques; two calibrated methods-CS SENSE and l1SPIRiT and two calibration free techniques-Distributed CS and SAKE. Our method yields better reconstruction results than all of them.

  19. Bioinformatics and Astrophysics Cluster (BinAc)

    NASA Astrophysics Data System (ADS)

    Krüger, Jens; Lutz, Volker; Bartusch, Felix; Dilling, Werner; Gorska, Anna; Schäfer, Christoph; Walter, Thomas

    2017-09-01

    BinAC provides central high performance computing capacities for bioinformaticians and astrophysicists from the state of Baden-Württemberg. The bwForCluster BinAC is part of the implementation concept for scientific computing for the universities in Baden-Württemberg. Community specific support is offered through the bwHPC-C5 project.

  20. 7 CFR 1737.31 - Area Coverage Survey (ACS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Area Coverage Survey (ACS). 1737.31 Section 1737.31... Studies-Area Coverage Survey and Loan Design § 1737.31 Area Coverage Survey (ACS). (a) The Area Coverage Survey (ACS) is a market forecast of service requirements of subscribers in a proposed service area. (b...

  1. 7 CFR 1737.31 - Area Coverage Survey (ACS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Area Coverage Survey (ACS). 1737.31 Section 1737.31... Studies-Area Coverage Survey and Loan Design § 1737.31 Area Coverage Survey (ACS). (a) The Area Coverage Survey (ACS) is a market forecast of service requirements of subscribers in a proposed service area. (b...

  2. 7 CFR 1737.31 - Area Coverage Survey (ACS).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 11 2013-01-01 2013-01-01 false Area Coverage Survey (ACS). 1737.31 Section 1737.31... Studies-Area Coverage Survey and Loan Design § 1737.31 Area Coverage Survey (ACS). (a) The Area Coverage Survey (ACS) is a market forecast of service requirements of subscribers in a proposed service area. (b...

  3. 7 CFR 1737.31 - Area Coverage Survey (ACS).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 11 2012-01-01 2012-01-01 false Area Coverage Survey (ACS). 1737.31 Section 1737.31... Studies-Area Coverage Survey and Loan Design § 1737.31 Area Coverage Survey (ACS). (a) The Area Coverage Survey (ACS) is a market forecast of service requirements of subscribers in a proposed service area. (b...

  4. 7 CFR 1737.31 - Area Coverage Survey (ACS).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Studies-Area Coverage Survey and Loan Design § 1737.31 Area Coverage Survey (ACS). (a) The Area Coverage Survey (ACS) is a market forecast of service requirements of subscribers in a proposed service area. (b... 7 Agriculture 11 2014-01-01 2014-01-01 false Area Coverage Survey (ACS). 1737.31 Section 1737.31...

  5. 21 CFR 880.5500 - AC-powered patient lift.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered patient lift. 880.5500 Section 880.5500... Devices § 880.5500 AC-powered patient lift. (a) Identification. An AC-powered lift is an electrically powered device either fixed or mobile, used to lift and transport patients in the horizontal or other...

  6. 21 CFR 880.5500 - AC-powered patient lift.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered patient lift. 880.5500 Section 880.5500... Devices § 880.5500 AC-powered patient lift. (a) Identification. An AC-powered lift is an electrically powered device either fixed or mobile, used to lift and transport patients in the horizontal or other...

  7. Effect of Medial Patellofemoral Ligament Reconstruction Method on Patellofemoral Contact Pressures and Kinematics.

    PubMed

    Stephen, Joanna M; Kittl, Christoph; Williams, Andy; Zaffagnini, Stefano; Marcheggiani Muccioli, Giulio Maria; Fink, Christian; Amis, Andrew A

    2016-05-01

    There remains a lack of evidence regarding the optimal method when reconstructing the medial patellofemoral ligament (MPFL) and whether some graft constructs can be more forgiving to surgical errors, such as overtensioning or tunnel malpositioning, than others. The null hypothesis was that there would not be a significant difference between reconstruction methods (eg, graft type and fixation) in the adverse biomechanical effects (eg, patellar maltracking or elevated articular contact pressure) resulting from surgical errors such as tunnel malpositioning or graft overtensioning. Controlled laboratory study. Nine fresh-frozen cadaveric knees were placed on a customized testing rig, where the femur was fixed but the tibia could be moved freely from 0° to 90° of flexion. Individual quadriceps heads and the iliotibial tract were separated and loaded to 205 N of tension using a weighted pulley system. Patellofemoral contact pressures and patellar tracking were measured at 0°, 10°, 20°, 30°, 60°, and 90° of flexion using pressure-sensitive film inserted between the patella and trochlea, in conjunction with an optical tracking system. The MPFL was transected and then reconstructed in a randomized order using a (1) double-strand gracilis tendon, (2) quadriceps tendon, and (3) tensor fasciae latae allograft. Pressure maps and tracking measurements were recorded for each reconstruction method in 2 N and 10 N of tension and with the graft positioned in the anatomic, proximal, and distal femoral tunnel positions. Statistical analysis was undertaken using repeated-measures analyses of variance, Bonferroni post hoc analyses, and paired t tests. Anatomically placed grafts during MPFL reconstruction tensioned to 2 N resulted in the restoration of intact medial joint contact pressures and patellar tracking for all 3 graft types investigated (P > .050). However, femoral tunnels positioned proximal or distal to the anatomic origin resulted in significant increases in the mean

  8. AC-electric field dependent electroformation of giant lipid vesicles.

    PubMed

    Politano, Timothy J; Froude, Victoria E; Jing, Benxin; Zhu, Yingxi

    2010-08-01

    Giant vesicles of larger than 5 microm, which have been of intense interest for their potential as drug delivery vehicles and as a model system for cell membranes, can be rapidly formed from a spin-coated lipid thin film under an electric field. In this work, we explore the AC-field dependent electroformation of giant lipid vesicles in aqueous media over a wide range of AC-frequency from 1 Hz to 1 MHz and peak-to-peak field strength from 0.212 V/mm to 40 V/mm between two parallel conducting electrode surfaces. By using fluorescence microscopy, we perform in-situ microscopic observations of the structural evolution of giant vesicles formed from spin-coated lipid films under varied uniform AC-electric fields. The real-time observation of bilayer bulging from the lipid film, vesicle growth and fusing further examine the critical role of AC-induced electroosmotic flow of surrounding fluids for giant vesicle formation. A rich AC-frequency and field strength phase diagram is obtained experimentally to predict the AC-electroformation of giant unilamellar vesicles (GUVs) of l-alpha-phosphatidylcholine, where a weak dependence of vesicle size on AC-frequency is observed at low AC-field voltages, showing decreased vesicle size with a narrowed size distribution with increased AC-frequency. Formation of vesicles was shown to be constrained by an upper field strength of 10 V/mm and an upper AC-frequency of 10 kHz. Within these parameters, giant lipid vesicles were formed predominantly unilamellar and prevalent across the entire electrode surfaces. Copyright 2010 Elsevier B.V. All rights reserved.

  9. The AC-120: The advanced commercial transport

    NASA Technical Reports Server (NTRS)

    Duran, David; Griffin, Ernest; Mendoza, Saul; Nguyen, Son; Pickett, Tim; Noernberg, Clemm

    1993-01-01

    The main objective of this design was to fulfill a need for a new airplane to replace the aging 100 to 150 passenger, 1500 nautical mile range aircraft such as the Douglas DC9 and Boeing 737-100 airplanes. After researching the future aircraft market, conducting extensive trade studies, and analysis on different configurations, the AC-120 Advanced Commercial Transport final design was achieved. The AC-120's main design features include the incorporation of a three lifting surface configuration which is powered by two turboprop engines. The AC-120 is an economically sensitive aircraft which meets the new FM Stage Three noise requirements, and has lower NO(x) emissions than current turbofan powered airplanes. The AC-120 also improves on its contemporaries in passenger comfort, manufacturing, and operating cost.

  10. Cry1Ac production is costly for native plants attacked by non-Cry1Ac-targeted herbivores in the field.

    PubMed

    McGale, Erica; Diezel, Celia; Schuman, Meredith C; Baldwin, Ian T

    2018-05-13

    Plants are the primary producers in most terrestrial ecosystems and have complex defense systems to protect their produce. Defense-deficient, high-yielding agricultural monocultures attract abundant nonhuman consumers, but are alternatively defended through pesticide application and genetic engineering to produce insecticidal proteins such as Cry1Ac (Bacillus thuringiensis). These approaches alter the balance between yield protection and maximization but have been poorly contextualized to known yield-defense trade-offs in wild plants. The native plant Nicotiana attenuata was used to compare yield benefits of plants transformed to be defenseless to those with a full suite of naturally evolved defenses, or additionally transformed to ectopically produce Cry1Ac. An insecticide treatment allowed us to examine yield under different herbivore loads in N. attenuata's native habitat. Cry1Ac, herbivore damage, and growth parameters were monitored throughout the season. Biomass and reproductive correlates were measured at season end. Non-Cry1Ac-targeted herbivores dominated on noninsecticide-treated plants, and increased the yield drag of Cry1Ac-producing plants in comparison with endogenously defended or undefended plants. Insecticide-sprayed Cry1Ac-producing plants lagged less in stalk height, shoot biomass, and flower production. In direct comparison with the endogenous defenses of a native plant, Cry1Ac production did not provide yield benefits for plants under observed herbivore loads in a field study. © 2018 The Authors New Phytologist © 2018 New Phytologist Trust.

  11. Fascial flap reconstruction of the hand: a single surgeon's 30-year experience.

    PubMed

    Carty, Matthew J; Taghinia, Amir; Upton, Joseph

    2010-03-01

    The reconstruction of complex hand wounds is challenging due to the requirements for thin and pliable coverage with a reliable vascular supply, potential for sensibility, and provision of a gliding surface. Fascial flaps represent an excellent option for the reconstruction of these complicated defects. A retrospective review of fascial flap reconstructive procedures to the hand undertaken by a single microsurgeon was performed for operations occurring between 1979 and 2009. Both pedicled and free tissue transfer procedures were included in both pediatric and adult patients. Data were culled from a combination of patient charts, hospital records, radiographic studies, and clinical photographs. Sixty fascial flap reconstructive procedures to the hand were analyzed in 60 patients from the defined 30-year period. The most common pathological process necessitating reconstruction was acute trauma (n = 32, 53 percent). Most of the soft-tissue injuries included in the study sample were located on the dorsal hand and wrist (n = 27, 45 percent). The most commonly utilized reconstructive modality was the temporoparietal fascial flap (n = 35, 58 percent). Most reconstructions were completed as free tissue transfers (n = 46, 77 percent). Perioperative complications were relatively minor; no flap losses were recorded. All cases studied demonstrated excellent long-term coverage with no evidence of underlying tendon adhesion or contracture. Fascial flaps represent an excellent option for coverage of soft-tissue defects of the hand that are not amenable to reconstruction with skin grafting alone, particularly for localized defects with denuded tendons or exposed joints.

  12. Return to motor activity after anterior cruciate ligament reconstruction--pilot study.

    PubMed

    Stańczak, Katarzyna; Domżalski, Marcin; Synder, Marek; Sibiński, Marcin

    2014-01-01

    Background. Reconstruction surgery is the most frequent treatment for patients with anterior cruciate ligament (ACL) lesions. The goal of the study was to present patients' subjective evaluation of their return to motor activity after ACL reconstruction and investigate whether and what demographic or clinical factors determine the recovery of physical function of ACL reconstruction patients. Material and methods. The study involved a group of fifty (50) patients who underwent ACL reconstruction. The mean age of patients was 32 years. A questionnaire was used to collect data from the patients. The first part of the questionnaire was concerned with personal and clinical data, while the second part was the KOOS form. Results. The incidence of unfavourable, post-operative symptoms was lower in elderly patients, as well as in those with longer periods between injury and reconstruction. The patients in whom the patellar ligament was used for the reconstruction demonstrated better outcomes as regards returning to sports and recreational activity than those in whom flexor tendons were used. The patients who returned to practising a sport reported more pain episodes and problems with daily and sports activities. Their quality of life was inferior to those who did not return to unrestricted sports activity. Conclusions. 1. Neither sex nor BMI has any statistically significant effect on the recovery of mobility after ACL reconstruction. 2. ACL reconstruction with a graft harvested from the central band of the patellar ligament appears to be more appropriate for patients willing to return to full sports and recreational activity. 3. It is better to carry our ACL reconstruction when normal knee joint function has been regained and injury-related symptoms have subsided.

  13. Revision with suture-tape augmentation after failed collateral ligament reconstruction for chronic interphalangeal instability of the hallux.

    PubMed

    Cho, Byung-Ki; Park, Ji-Kang; Choi, Seung-Myung; SooHoo, Nelson F

    2017-12-01

    Chronic varus instability or recurrent subluxation following isolated interphalangeal dislocation of the hallux is a rare injury. No consensus has been reached regarding the best joint-salvage procedure for patients with the failed collateral ligament reconstruction using tendon graft. We report a case who achieved satisfactory clinical outcome through a modified surgical procedure (revision collateral ligament reconstruction augmented with suture-tape). Copyright © 2017 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  14. ACS from development to operations

    NASA Astrophysics Data System (ADS)

    Caproni, Alessandro; Colomer, Pau; Jeram, Bogdan; Sommer, Heiko; Chiozzi, Gianluca; Mañas, Miguel M.

    2016-08-01

    The ALMA Common Software (ACS), provides the infrastructure of the distributed software system of ALMA and other projects. ACS, built on top of CORBA and Data Distribution Service (DDS) middleware, is based on a Component- Container paradigm and hides the complexity of the middleware allowing the developer to focus on domain specific issues. The transition of the ALMA observatory from construction to operations brings with it that ACS effort focuses primarily on scalability, stability and robustness rather than on new features. The transition came together with a shorter release cycle and a more extensive testing. For scalability, the most problematic area has been the CORBA notification service, used to implement the publisher subscriber pattern because of the asynchronous nature of the paradigm: a lot of effort has been spent to improve its stability and recovery from run time errors. The original bulk data mechanism, implemented using the CORBA Audio/Video Streaming Service, showed its limitations and has been replaced with a more performant and scalable DDS implementation. Operational needs showed soon the difference between releases cycles for Online software (i.e. used during observations) and Offline software, which requires much more frequent releases. This paper attempts to describe the impact the transition from construction to operations had on ACS, the solution adopted so far and a look into future evolution.

  15. The human first carpometacarpal joint: osteoarthritic degeneration and 3-dimensional modeling.

    PubMed

    Kovler, Maksim; Lundon, Katie; McKee, Nancy; Agur, Anne

    2004-01-01

    The purpose of this study was to gain insight into potential mechanical factors contributing to osteoarthritis of the human first carpometacarpal joint (CMC). This was accomplished by creating three-dimensional (3-D) computer models of the articular surfaces of CMC joints of older humans and by determining their locus of cartilage degeneration. The research questions of this study were: 1) What is the articular wear pattern of cartilage degeneration in CMC osteoarthritis?, (2) Are there significant topographic differences in joint area and contour between the joints of males and females?, and 3) Are there measurable bony joint recesses consistently found within the joint? The articular surfaces of 25 embalmed cadaveric joints (from 13 cadavers) were graded for degree of osteoarthritis, and the location of degeneration was mapped using a dissection microscope. The surfaces of 14 mildly degenerated joints were digitized and reconstructed as 3-D computer models using the Microscribe 3D-X Digitizer and the Rhinoceros 2.0 NURBS Modeling Software. This technology provided accurate and reproducible information on joint area and topography. The dorsoradial trapezial region was found to be significantly more degenerated than other quadrants in both males and females. Mean trapezial articular surface area was 197 mm 2 in males and 160 mm(2) in females; the respective mean areas for the metacarpal were 239 mm(2) in males and 184 mm(2) in females. Joints of females were found to be significantly more concave in radioulnar profile than those of males. Three bony joint recesses were consistently found, two in the radial and ulnar aspects of the trapezium and the third in the palmar surface of the metacarpal.

  16. The biomechanical influence of the deltotrapezoid fascia on horizontal and vertical acromioclavicular joint stability.

    PubMed

    Pastor, M F; Averbeck, A K; Welke, B; Smith, T; Claassen, L; Wellmann, M

    2016-04-01

    Many studies have investigated the biomechanical influence of the acromioclavicular (AC) and coracoclavicular (CC) ligaments on the stability of the acromioclavicular joint (ACJ). It has been shown that augmentation of the CC ligaments alone can result in residual horizontal instability. Our hypothesis was that the DTF would have a significant stabilizing effect on horizontal ACJ stability. In a biomechanical in vitro study a sequential injury of the ACJ was created on eight shoulders from full body, which were placed in an upright sitting position. The translation and rotation of the clavicle were measured in relation to the acromion using an optical navigation system in various states during thoracic-humeral elevation, abduction, and horizontal adduction. The three states were: an intact shoulder, complete sectioning of the AC ligaments, and a circular lesion of the DTF. Compared to the intact state we found a significant increase in anterior rotation of the clavicle of 1.11° (p = 0.012) and a tendency in lateral translation of 2.71 mm (p = 0.017) in relation to the acromion, with a combined lesion of AC ligaments and DTF. No significant differences were found between the intact state and the isolated dissected AC ligaments as well in adduction as elevation. A combined lesion of the AC ligaments and the DTF resulted in a quantitatively small but significant increase in anterior rotation and a tendency in lateral translation of the clavicle in relation to the acromion. These differences were quantitatively small, so that the clinical relevance of the stabilization effect of combined AC ligaments and DTF injuries is questionable.

  17. ACS and STEMI treatment: gender-related issues.

    PubMed

    Chieffo, Alaide; Buchanan, Gill Louise; Mauri, Fina; Mehilli, Julinda; Vaquerizo, Beatriz; Moynagh, Anouska; Mehran, Roxana; Morice, Marie-Claude

    2012-08-01

    Cardiovascular disease is the leading cause of death amongst women, with acute coronary syndromes (ACS) representing a significant proportion. It has been reported that in women presenting with ACS there is underdiagnosis and consequent undertreatment leading to an increase in hospital and long-term mortality. Several factors have to be taken into account, including lack of awareness both at patient and at physician level. Women are generally not aware of the cardiovascular risk and symptoms, often atypical, and therefore wait longer to seek medical attention. In addition, physicians often underestimate the risk of ACS in women leading to a further delay in accurate diagnosis and timely appropriate treatment, including cardiac catheterisation and primary percutaneous coronary intervention, with consequent delayed revascularisation times. It has been acknowledged by the European Society of Cardiology that gender disparities do exist, with a Class I, Level of Evidence B recommendation that both genders should be treated in the same way when presenting with ACS. However, there is still a lack of awareness and the mission of Women in Innovation, in association with Stent for Life, is to change the perception of women with ACS and to achieve prompt diagnosis and treatment.

  18. Electrostatic coalescence system with independent AC and DC hydrophilic electrodes

    DOEpatents

    Hovarongkura, A. David; Henry, Jr., Joseph D.

    1981-01-01

    An improved electrostatic coalescence system is provided in which independent AC and DC hydrophilic electrodes are employed to provide more complete dehydration of an oil emulsion. The AC field is produced between an AC electrode array and the water-oil interface wherein the AC electrode array is positioned parallel to the interface which acts as a grounded electrode. The emulsion is introduced into the AC field in an evenly distributed manner at the interface. The AC field promotes drop-drop and drop-interface coalescence of the water phase in the entering emulsion. The continuous oil phase passes upward through the perforated AC electrode array and enters a strong DC field produced between closely spaced DC electrodes in which small dispersed droplets of water entrained in the continuous phase are removed primarily by collection at hydrophilic DC electrodes. Large droplets of water collected by the electrodes migrate downward through the AC electrode array to the interface. All phase separation mechanisms are utilized to accomplish more complete phase separation.

  19. [A primary application and evaluation of temporomandibular joint replacement with stock prosthesis].

    PubMed

    Zhang, Xiao-hu; Chen, Min-jie; Qiu, Ya-ting; Yang, Chi

    2012-06-01

    To evaluate the effect of total joint replacement in treatment of temporomandibular joint(TMJ) osteoarthropathy with stock prostheses. Six female patients involving 10 joints (2 unilateral and 4 bilateral), with an average age of 59 years old, were involved in this study. Three patients (5 joints) were diagnosed as internal derangement in V stage depending on MRI, 3D-CT findings and clinical characteristics. The other 3 patients (5 joints) had histories of failed temporomandibular joint operation using costochondral graft or temporalis fascial flap. The maximal mouth opening was 1.9 cm on average (range, 1.0 to 2.9cm). All the joints were replaced with Biomet standard prosthesis under general anesthesia. The follow-up period was from 7 to 49 months (average, 17.5 months). All the operations were successfully performed. Heterotopic ossification happened in a bilateral case 1 year postoperatively. One patient with bilateral joint disease complained of severe uncomfortable feeling in the region of the ears and the temples, although there was no significant positive signs according to an ENT examination. Pain relief of the joint and mouth opening improvement were significant in 4 patients. No failure was noted secondary to infection or loosening of the prostheses. The occlusal relationship kept stable postoperatively in all cases. Total TMJ joint replacement with standard prosthesis is a good choice for TMJ reconstruction. It can significantly reduce joint pain and the mouth opening limitation resulted from osteoarthritis. Long-term result remains to be evaluated based on a long-term follow-up.

  20. Reconstruction of ECG signals in presence of corruption.

    PubMed

    Ganeshapillai, Gartheeban; Liu, Jessica F; Guttag, John

    2011-01-01

    We present an approach to identifying and reconstructing corrupted regions in a multi-parameter physiological signal. The method, which uses information in correlated signals, is specifically designed to preserve clinically significant aspects of the signals. We use template matching to jointly segment the multi-parameter signal, morphological dissimilarity to estimate the quality of the signal segment, similarity search using features on a database of templates to find the closest match, and time-warping to reconstruct the corrupted segment with the matching template. In experiments carried out on the MIT-BIH Arrhythmia Database, a two-parameter database with many clinically significant arrhythmias, our method improved the classification accuracy of the beat type by more than 7 times on a signal corrupted with white Gaussian noise, and increased the similarity to the original signal, as measured by the normalized residual distance, by more than 2.5 times.

  1. [Reconstruction and balance of soft tissue in hemi-shoulder replacement for patients with four-part fracture of the proximal humerus].

    PubMed

    Wu, Xing; Lou, Lie-ming; Chen, Zheng-rong; Zhang, Guang-jian

    2008-10-01

    To explore the effective skills of reconstruction and balance of soft tissue in hemi-shoulder replacement for patients with four-part fracture of the proximal humerus in order to avoid postoperative complications of joint instability and great tubercle displacement. From June 2002 to June 2006, 25 patients with Neer four-part fracture of the proximal humerus were adopted in the study which included 15 females and 10 males, with the mean age of 66 years (ranged from 56 years to 80 years). They were treated with humeral head replacement and should joint reparation simultaneously by modified operation approach and reconstruction and balance skills of soft tissue. The mean duration of follow-up was 2.3 years (ranged from 1 to 4.5 years). No infection, nerve damage and prosthesis loosing were found in all cases. Two cases of infra-forward dislocation or subluxation occurred due to affected limb placed on abduction splint postoperatively. One case occurred prosthesis upward displacement due to early active abduction exercise but no complains. Neither joint instability nor displacement and malunion of great tubercle were found in other patients. According to Neer scoring system, 6 cases were rated as excellent, 15 as good and 5 as fair. The good and excellent rate was 84%. In hemi-shoulder replacement for patients with Neer four-part fracture the modified operation approach and reconstruction and balance of soft tissue skills combined with rational rehabilitation exercise can prevent postoperative shoulder joint instability and displacement and malunion of great tubercle.

  2. Massive trapezial metastasis from gastric adenocarcinoma resected and reconstructed with a vascularized scapular bone graft

    PubMed Central

    Okamoto, Masanori; Yamazaki, Hiroshi; Yoshimura, Yasuo; Aoki, Kaoru; Tanaka, Atsushi; Kato, Hiroyuki

    2017-01-01

    Abstract Rationale: Isolated metastasis to the hand bones is very rare. Only seven cases of metastasis to the trapezium have been reported. To the best of our knowledge, this is the first report of a single metastasis to the trapezium from a gastric adenocarcinoma. Patient concerns: A 62-year-old man presented with pain and massive swelling in the right carpometacarpal joint of the thumb. Diagnoses: The patient was diagnosed with trapezial metastasis of advanced gastric adenocarcinoma. Interventions: The patient underwent systemic chemotherapy with cisplatin and S-1, radiotherapy to the metastatic bone, and treatment with denosumab. One year later, the huge metastatic tumor was resected, and the hand was reconstructed using vascularized scapular bone. Outcomes: Eighteen months postoperatively, the patient was satisfied with the appearance of the reconstructed hand and was able to use his right thumb in activities of daily living. Lessons: Although rare, metastasis to the trapezium should be considered in patients with persistent and progressive thumb CMC joint pain. PMID:29390390

  3. Use of an AC/DC/AC Electrochemical Technique to Assess the Durability of Protection Systems for Magnesium Alloys

    NASA Astrophysics Data System (ADS)

    Song, Sen; McCune, Robert C.; Shen, Weidian; Wang, Yar-Ming

    One task under the U.S. Automotive Materials Partnership (USAMP) "Magnesium Front End Research and Development" (MFERD) Project has been the evaluation of methodologies for the assessment of protective capability for a variety of proposed protection schemes for this hypothesized multi-material, articulated structure. Techniques which consider the entire protection system, including both pretreatments and topcoats are of interest. In recent years, an adaptation of the classical electrochemical impedance spectroscopy (EIS) approach using an intermediate cathodic DC polarization step (viz. AC/DC/AC) has been employed to accelerate breakdown of coating protection, specifically at the polymer-pretreatment interface. This work reports outcomes of studies to employ the AC/DC/AC approach for comparison of protective coatings to various magnesium alloys considered for front end structures. In at least one instance, the protective coating system breakdown could be attributed to the poorer intrinsic corrosion resistance of the sheet material (AZ31) relative to die-cast AM60B.

  4. Should fee-for-service be for all guideline-advocated acute coronary syndrome (ACS) care? Observations from the Snapshot ACS study.

    PubMed

    Briffa, Thomas G; Hammett, Christopher J; Cross, David B; Macisaac, Andrew I; Rankin, James M; Board, Neville; Carr, Bridie; Hyun, Karice K; French, John; Brieger, David B; Chew, Derek P

    2015-09-01

    The aim of the present study was to explore the association of health insurance status on the provision of guideline-advocated acute coronary syndrome (ACS) care in Australia. Consecutive hospitalisations of suspected ACS from 14 to 27 May 2012 enrolled in the Snapshot study of Australian and New Zealand patients were evaluated. Descriptive and logistic regression analysis was performed to evaluate the association of patient risk and insurance status with the receipt of care. In all, 3391 patients with suspected ACS from 247 hospitals (23 private) were enrolled in the present study. One-third of patients declared private insurance coverage; of these, 27.9% (304/1088) presented to private facilities. Compared with public patients, privately insured patients were more likely to undergo in-patient echocardiography and receive early angiography; furthermore, in those with a discharge diagnosis of ACS, there was a higher rate of revascularisation (P < 0.001). Each of these attracts potential fee-for-service. In contrast, proportionately fewer privately insured ACS patients were discharged on selected guideline therapies and were referred to a secondary prevention program (P = 0.056), neither of which directly attracts a fee. Typically, as GRACE (the Global Registry of Acute Coronary Events) risk score rose, so did the level of ACS care; however, propensity-adjusted analyses showed lower in-hospital adverse events among the insured group (odds ratio 0.68; 95% confidence interval 0.52-0.88; P = 0.004). Fee-for-service reimbursement may explain differences in the provision of selected guideline-advocated components of ACS care between privately insured and public patients.

  5. Cadmium-induced ethylene production and responses in Arabidopsis thaliana rely on ACS2 and ACS6 gene expression

    PubMed Central

    2014-01-01

    Background Anthropogenic activities cause metal pollution worldwide. Plants can absorb and accumulate these metals through their root system, inducing stress as a result of excess metal concentrations inside the plant. Ethylene is a regulator of multiple plant processes, and is affected by many biotic and abiotic stresses. Increased ethylene levels have been observed after exposure to excess metals but it remains unclear how the increased ethylene levels are achieved at the molecular level. In this study, the effects of cadmium (Cd) exposure on the production of ethylene and its precursor 1-aminocyclopropane-1-carboxylic acid (ACC), and on the expression of the ACC Synthase (ACS) and ACC Oxidase (ACO) multigene families were investigated in Arabidopsis thaliana. Results Increased ethylene release after Cd exposure was directly measurable in a system using rockwool-cultivated plants; enhanced levels of the ethylene precursor ACC together with higher mRNA levels of ethylene responsive genes: ACO2, ETR2 and ERF1 also indicated increased ethylene production in hydroponic culture. Regarding underlying mechanisms, it was found that the transcript levels of ACO2 and ACO4, the most abundantly expressed members of the ACO multigene family, were increased upon Cd exposure. ACC synthesis is the rate-limiting step in ethylene biosynthesis, and transcript levels of both ACS2 and ACS6 showed the highest increase and became the most abundant isoforms after Cd exposure, suggesting their importance in the Cd-induced increase of ethylene production. Conclusions Cadmium induced the biosynthesis of ACC and ethylene in Arabidopsis thaliana plants mainly via the increased expression of ACS2 and ACS6. This was confirmed in the acs2-1acs6-1 double knockout mutants, which showed a decreased ethylene production, positively affecting leaf biomass and resulting in a delayed induction of ethylene responsive gene expressions without significant differences in Cd contents between wild-type and

  6. Regeneration of spine disc and joint cartilages under temporal and space modulated laser radiation

    NASA Astrophysics Data System (ADS)

    Sobol, E.; Shekhter, A.; Baskov, A.; Baskov, V.; Baum, O.; Borchshenko, I.; Golubev, V.; Guller, A.; Kolyshev, I.; Omeltchenko, A.; Sviridov, A.; Zakharkina, O.

    2009-02-01

    The effect of laser radiation on the generation of hyaline cartilage in spine disc and joints has been demonstrated. The paper considers physical processes and mechanisms of laser regeneration, presents results of investigations aimed to optimize laser settings and to develop feedback control system for laser reconstruction of spine discs. Possible mechanisms of laser-induced regeneration include: (1) Space and temporary modulated laser beam induces nonhomogeneous and pulse repetitive thermal expansion and stress in the irradiated zone of cartilage. Mechanical effect due to controllable thermal expansion of the tissue and micro and nano gas bubbles formation in the course of the moderate (up to 45-50 oC) heating of the NP activate biological cells (chondrocytes) and promote cartilage regeneration. (2) Nondestructive laser radiation leads to the formation of nano and micro-pores in cartilage matrix. That promotes water permeability and increases the feeding of biological cells. Results provide the scientific and engineering basis for the novel low-invasive laser procedures to be used in orthopedics for the treatment cartilages of spine and joints. The technology and equipment for laser reconstruction of spine discs have been tested first on animals, and then in a clinical trial. Since 2001 the laser reconstruction of intervertebral discs have been performed for 340 patients with chronic symptoms of low back or neck pain who failed to improve with non-operative care. Substantial relief of back pain was obtained in 90% of patients treated who returned to their daily activities. The experiments on reparation of the defects in articular cartilage of the porcine joints under temporal and spase modulated laser radiation have shown promising results.

  7. Microstructure and Properties of Lap Joint Between Aluminum Alloy and Galvanized Steel by CMT

    NASA Astrophysics Data System (ADS)

    Niu, Song; Chen, Su; Dong, Honggang; Zhao, Dongsheng; Zhang, Xiaosheng; Guo, Xin; Wang, Guoqiang

    2016-05-01

    Lap joining of 1-mm-thick Novelist AC 170 PX aluminum alloy to 1.2-mm-thick ST06 Z galvanized steel sheets for automotive applications was conducted by cold metal transfer advanced welding process with ER4043 and ER4047 filler wires. Under the optimized welding parameters with ER4043 filler wire, the tensile shear strength of joint was 189 MPa, reaching 89% of the aluminum alloy base metal. Microstructure and elemental distribution were characterized by optical metalloscope and electron probe microanalysis. The lap joints with ER4043 filler wire had smaller wetting angle and longer bonded line length with better wettability than with ER4047 filler wire during welding with same parameters. The needle-like Al-Fe-Si intermetallic compounds (IMCs) were spalled into the weld and brought negative effect to the tensile strength of joints. With increasing welding current, the needle-like IMCs grew longer and spread further into the weld, which would deteriorate the tensile shear strength.

  8. Modelling ac ripple currents in HTS coated conductors

    NASA Astrophysics Data System (ADS)

    Xu, Zhihan; Grilli, Francesco

    2015-10-01

    Dc transmission using high temperature superconducting (HTS) coated conductors (CCs) offers a promising solution to the globally growing demand for effective, reliable and economic transmission of green energy up to the gigawatt level over very long distances. The credible estimation of the losses and thereby the heat dissipation involved, where ac ripples (introduced in rectification/ac-dc conversion) are viewed as a potential source of notable contribution, is highly essential for the rational design of practical HTS dc transmission cables and corresponding cryogenic systems to fulfil this demand. Here we report a targeted modelling study into the ac losses in a HTS CC subject to dc and ac ripple currents simultaneously, by solving Maxwell’s equations using the finite element method (FEM) in the commercial software package COMSOL. It is observed that the instantaneous loss exhibits only one peak per cycle in the HTS CC subject to sinusoidal ripples, given that the amplitude of the ac ripples is smaller than approximately 20% of that of the dc current. This is a distinct contrast to the usual observation of two peaks per cycle in a HTS CC subject to ac currents only. The unique mechanism is also revealed, which is directly associated with the finding that, around any local minima of the applied ac ripples, the critical state of -J c is never reached at the edges of the HTS CC, as it should be according to the Bean model. When running further into the longer term, it is discovered that the ac ripple loss of the HTS CC in full-wave rectification decays monotonically, at a speed which is found to be insensitive to the frequency of the applied ripples within our targeted situations, to a relatively low level of approximately 1.38 × 10-4 W m-1 in around 1.7 s. Comparison between this level and other typical loss contributions in a HTS dc cable implies that ac ripple currents in HTS CCs should only be considered as a minor source of dissipation in superconducting dc

  9. ACS Data Handbook v.6.0

    NASA Astrophysics Data System (ADS)

    Gonzaga, S.; et al.

    2011-03-01

    ACS was designed to provide a deep, wide-field survey capability from the visible to near-IR using the Wide Field Camera (WFC), high resolution imaging from the near-UV to near-IR with the now-defunct High Resolution Camera (HRC), and solar-blind far-UV imaging using the Solar Blind Camera (SBC). The discovery efficiency of ACS's Wide Field Channel (i.e., the product of WFC's field of view and throughput) is 10 times greater than that of WFPC2. The failure of ACS's CCD electronics in January 2007 brought a temporary halt to CCD imaging until Servicing Mission 4 in May 2009, when WFC functionality was restored. Unfortunately, the high-resolution optical imaging capability of HRC was not recovered.

  10. Reconstruction of the proximal humerus with a composite of extracorporeally irradiated bone and endoprosthesis following excision of high grade primary bone sarcomas.

    PubMed

    Moran, Matthew; Stalley, Paul D

    2009-10-01

    Functional reconstruction of the shoulder joint following excision of a malignant proximal humeral tumour is a difficult proposition. Eleven patients with primary osteosarcoma or Ewing's sarcoma underwent reconstruction with a composite of extra-corporeally irradiated autograft with the addition of a long stemmed hemiarthroplasty. At a mean follow-up of 5.8 years two patients had died from disseminated disease and one patient had undergone amputation for local recurrence. The eight patients with a surviving limb were examined clinically and radiographically. The mean Toronto Extremity Salvage Score was 74 and Musculo-Skeletal Tumour Society score 66. Rotation was well preserved but abduction (mean 32 degrees ) and flexion (40 degrees ) were poor. There was a high rate of secondary surgery, with five out of eleven patients requiring re-operation for complications of reconstruction surgery. Radiographic estimate of graft remaining at follow up was 71%. There were no infections, revisions or radiographic failures. Whilst the reconstructions were durable in the medium term, the functional outcome was no better than with other reported reconstructive methods. The composite technique was especially useful in subtotal humeral resections, allowing preservation of the elbow joint even with very distal osteotomy. Bone stock is restored, which may be useful for future revision surgery in this young group of patients.

  11. Pure Varus Injury to the Knee Joint.

    PubMed

    Yoo, Jae Ho; Lee, Jung Ha; Chang, Chong Bum

    2015-06-01

    A 30-year-old male was involved in a car accident. Radiographs revealed a depressed marginal fracture of the medial tibial plateau and an avulsion fracture of the fibular head. Magnetic resonance imaging showed avulsion fracture of Gerdy's tubercle, injury to the posterior cruciate ligament (PCL), posterior horn of the medial meniscus, and the attachments of the lateral collateral ligament and the biceps femoris tendon. The depressed fracture of the medial tibial plateau was elevated and stabilized using a cannulated screw and washer. The injured lateral and posterolateral corner (PLC) structures were repaired and augmented by PLC reconstruction. However, the avulsion fracture of Gerdy's tubercle was not fixed because it was minimally displaced and the torn PCL was also not repaired or reconstructed. We present a unique case of pure varus injury to the knee joint. This case contributes to our understanding of the mechanism of knee injury and provides insight regarding appropriate treatment plans for this type of injury.

  12. Abnormal tibiofemoral contact stress and its association with altered kinematics after center-center anterior cruciate ligament reconstruction: an in vitro study.

    PubMed

    Imhauser, Carl; Mauro, Craig; Choi, Daniel; Rosenberg, Eric; Mathew, Stephen; Nguyen, Joseph; Ma, Yan; Wickiewicz, Thomas

    2013-04-01

    Abnormal tibiofemoral contact stress and aberrant kinematics may influence the progression of osteoarthritis in the anterior cruciate ligament (ACL)-deficient and the ACL-reconstructed knee. However, relationships between contact stress and kinematics after ACL reconstruction are poorly understood. Therefore, we posed the following research questions: (1) How do ACL deficiency and reconstruction affect the kinematics of and contact stress in the tibiofemoral joint? (2) What kinematic differences are associated with abnormal contact stress after ACL reconstruction? Center-center ACL reconstruction will not restore knee kinematics and contact stress. Correlations will exist between abnormal contact stress and aberrant kinematics after ACL reconstruction. Controlled laboratory study. Clinical tests of anterior and rotational stability were simulated on 11 cadaveric knees using an industrial robot. Tests were conducted with the ACL intact, sectioned, and after single-bundle ACL reconstruction using a quadrupled hamstring autograft with tunnels drilled through the center of the native footprints. Kinematics were recorded during the tests. Contact stress was continuously recorded from a stress transducer fixed to the tibial plateau, and mean contact stress was calculated regionally. ACL deficiency resulted in increased mean contact stress in the posterior sectors of the medial and lateral compartments under anterior and rotational loads, respectively. Reconstruction reduced stress in these locations; however, contact stress abnormalities remained. On average, kinematics were overconstrained after ACL reconstruction (≤1.8 mm and ≤2.6° in all directions). However, combinations of overconstrained and underconstrained motions in abduction/adduction and medial-lateral translation in response to combined moments, and anterior-posterior translation, medial-lateral translation, and axial rotation in response to an anterior load were associated with abnormal mean contact

  13. POEM: Identifying Joint Additive Effects on Regulatory Circuits.

    PubMed

    Botzman, Maya; Nachshon, Aharon; Brodt, Avital; Gat-Viks, Irit

    2016-01-01

    Expression Quantitative Trait Locus (eQTL) mapping tackles the problem of identifying variation in DNA sequence that have an effect on the transcriptional regulatory network. Major computational efforts are aimed at characterizing the joint effects of several eQTLs acting in concert to govern the expression of the same genes. Yet, progress toward a comprehensive prediction of such joint effects is limited. For example, existing eQTL methods commonly discover interacting loci affecting the expression levels of a module of co-regulated genes. Such "modularization" approaches, however, are focused on epistatic relations and thus have limited utility for the case of additive (non-epistatic) effects. Here we present POEM (Pairwise effect On Expression Modules), a methodology for identifying pairwise eQTL effects on gene modules. POEM is specifically designed to achieve high performance in the case of additive joint effects. We applied POEM to transcription profiles measured in bone marrow-derived dendritic cells across a population of genotyped mice. Our study reveals widespread additive, trans-acting pairwise effects on gene modules, characterizes their organizational principles, and highlights high-order interconnections between modules within the immune signaling network. These analyses elucidate the central role of additive pairwise effect in regulatory circuits, and provide computational tools for future investigations into the interplay between eQTLs. The software described in this article is available at csgi.tau.ac.il/POEM/.

  14. ACS-Hach Programs: Supporting Excellence in High School Chemistry Teaching

    NASA Astrophysics Data System (ADS)

    Taylor, Terri

    2009-05-01

    In January 2009, the ACS received a gift of approximately $33 million from the Hach Scientific Foundation, the largest gift in the society's 133-year history. The foundation's programs will be continued by the ACS and will complement pre-existing ACS resources that support high school chemistry teaching. Three activities serve as the pillars of the ACS-Hach programs—the High School Chemistry Grant Program, the Second Career Teacher Scholarship Program, and the Land Grant University Scholars Program. Collectively, the ACS-Hach programs support high school chemistry teaching and learning by responding to the needs of both in-service and pre-service secondary teachers. The goals of each of the ACS-Hach programs align well with the ACS Mission—to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and its people.

  15. ACS Presents Science Education Report to Congress.

    ERIC Educational Resources Information Center

    Krieger, James

    1989-01-01

    Discusses an American Chemical Society (ACS)'s report on science education which is a synthesis of a series of policies developed by ACS. Summarizes recommendations in four areas: elementary teacher education; pre-high school curricula; university research funding; and underrepresented populations. (YP)

  16. Tribological characterization of the drill pipe tool joints reconditioned by using welding technologies

    NASA Astrophysics Data System (ADS)

    Caltaru, M.; Badicioiu, M.; Ripeanu, R. G.; Dinita, A.; Minescu, M.; Laudacescu, E.

    2018-01-01

    Drill pipe is a seamless steel pipe with upset ends fitted with special threaded ends that are known as tool joints. During drilling operations, the wall thickness of the drill pipe and the outside diameter of the tool joints will be gradually reduced due to wear. The present research work investigate the possibility of reconditioning the drill pipe tool joints by hardbanding with a new metal-cored coppered flux cored wire, Cr-Mo alloyed, using the gas metal active welding process, taking into considerations two different hardbanding technologies, consisting in: hardbanding drill pipe tool joints after removing the old hardbanding material and surface reconstruction with a compensation material (case A), and hardbanding tool joint drill pipe, without removing the old hardbanding material (case B). The present paper brings forward the experimental researches regarding the tribological characterization of the reconditioned drill pipe tool joint by performing macroscopic analyses, metallographic analyses, Vickers hardness measurement, chemical composition measurement and wear tests conducted on ball on disk friction couples, in order to certify the quality of the hardbanding obtained by different technological approaches, to validate the optimum technology.

  17. A dry-cooled AC quantum voltmeter

    NASA Astrophysics Data System (ADS)

    Schubert, M.; Starkloff, M.; Peiselt, K.; Anders, S.; Knipper, R.; Lee, J.; Behr, R.; Palafox, L.; Böck, A. C.; Schaidhammer, L.; Fleischmann, P. M.; Meyer, H.-G.

    2016-10-01

    The paper describes a dry-cooled AC quantum voltmeter system operated up to kilohertz frequencies and 7 V rms. A 10 V programmable Josephson voltage standard (PJVS) array was installed on a pulse tube cooler (PTC) driven with a 4 kW air-cooled compressor. The operating margins at 70 GHz frequencies were investigated in detail and found to exceed 1 mA Shapiro step width. A key factor for the successful chip operation was the low on-chip power consumption of 65 mW in total. A thermal interface between PJVS chip and PTC cold stage was used to avoid a significant chip overheating. By installing the cryocooled PJVS array into an AC quantum voltmeter setup, several calibration measurements of dc standards and calibrator ac voltages up to 2 kHz frequencies were carried out to demonstrate the full functionality. The results are discussed and compared to systems with standard liquid helium cooling. For dc voltages, a direct comparison measurement between the dry-cooled AC quantum voltmeter and a liquid-helium based 10 V PJVS shows an agreement better than 1 part in 1010.

  18. Fast myopic 2D-SIM super resolution microscopy with joint modulation pattern estimation

    NASA Astrophysics Data System (ADS)

    Orieux, François; Loriette, Vincent; Olivo-Marin, Jean-Christophe; Sepulveda, Eduardo; Fragola, Alexandra

    2017-12-01

    Super-resolution in structured illumination microscopy (SIM) is obtained through de-aliasing of modulated raw images, in which high frequencies are measured indirectly inside the optical transfer function. Usual approaches that use 9 or 15 images are often too slow for dynamic studies. Moreover, as experimental conditions change with time, modulation parameters must be estimated within the images. This paper tackles the problem of image reconstruction for fast super resolution in SIM, where the number of available raw images is reduced to four instead of nine or fifteen. Within an optimization framework, the solution is inferred via a joint myopic criterion for image and modulation (or acquisition) parameters, leading to what is frequently called a myopic or semi-blind inversion problem. The estimate is chosen as the minimizer of the nonlinear criterion, numerically calculated by means of a block coordinate optimization algorithm. The effectiveness of the proposed method is demonstrated for simulated and experimental examples. The results show precise estimation of the modulation parameters jointly with the reconstruction of the super resolution image. The method also shows its effectiveness for thick biological samples.

  19. Abnormal tibiofemoral contact stress and its association with altered kinematics following center-center ACL reconstruction: an in vitro study

    PubMed Central

    Imhauser, Carl; Mauro, Craig; Choi, Daniel; Rosenberg, Eric; Mathew, Stephen; Nguyen, Joseph; Ma, Yan; Wickiewicz, Thomas

    2014-01-01

    Background Abnormal tibiofemoral contact stress and aberrant kinematics may influence the progression of osteoarthritis in the ACL-deficient and the ACL-reconstructed knee. However, relationships between contact stress and kinematics following ACL reconstruction are poorly understood. Therefore, we posed the following research questions: (1) How do ACL deficiency and reconstruction affect kinematics of and contact stress in the tibiofemoral joint? (2) What kinematic differences are associated with abnormal contact stress following ACL reconstruction? Hypothesis/Purpose Center-center ACL reconstruction will not restore knee kinematics and contact stress. Correlations will exist between abnormal contact stress and aberrant kinematics following ACL reconstruction will exist. Study Design Controlled laboratory study Methods Clinical tests of anterior and rotational stability were simulated on eleven cadaveric knees using an industrial robot. Tests were conducted with the ACL intact, sectioned, and after single bundle ACL reconstruction using a quadrupled hamstring autograft with tunnels drilled through the center of the native footprints. Kinematics were recorded during the tests. Contact stress was continuously recorded from a stress transducer fixed to the tibial plateau and mean contact stress was calculated regionally. Results ACL deficiency resulted in increased mean contact stress in the posterior sectors of the medial and lateral compartments under anterior and rotational loads, respectively. Reconstruction reduced stress in these locations; however contact stress abnormalities remained. On average, kinematics were overconstrained following ACL reconstruction (≤1.8mm and ≤2.6° in all directions). However, combinations of overconstrained and underconstrained motions in ab/adduction and medial-lateral translation in response to combined moments, and axial rotation, anterior-posterior and medial-lateral translation in response to an anterior load were

  20. Patellofemoral Pressure Changes After Static and Dynamic Medial Patellofemoral Ligament Reconstructions.

    PubMed

    Rood, Akkie; Hannink, Gerjon; Lenting, Anke; Groenen, Karlijn; Koëter, Sander; Verdonschot, Nico; van Kampen, Albert

    2015-10-01

    Reconstructing the medial patellofemoral ligament (MPFL) has become a key procedure for stabilizing the patella. Different techniques to reconstruct the MPFL have been described: static techniques in which the graft is fixed rigidly to the bone or dynamic techniques with soft tissue fixation. Static MPFL reconstruction is most commonly used. However, dynamic reconstruction deforms more easily and presumably functions more like the native MPFL. The aim of the study was to evaluate the effect of the different MPFL fixation techniques on patellofemoral pressures compared with the native situation. The hypothesis was that dynamic reconstruction would result in patellofemoral pressures closer to those generated in an intact knee. Controlled laboratory study. Seven fresh-frozen knee specimens were tested in an in vitro knee joint loading apparatus. Tekscan pressure-sensitive films fixed to the retropatellar cartilage measured mean patellofemoral and peak pressures, contact area, and location of the center of force (COF) at fixed flexion angles from 0° to 110°. Four different conditions were tested: intact, dynamic, partial dynamic, and static MPFL reconstruction. Data were analyzed using linear mixed models. Static MPFL reconstruction resulted in higher peak and mean pressures from 60° to 110° of flexion (P < .001). There were no differences in pressure between the 2 different dynamic reconstructions and the intact situation (P > .05). The COF in the static reconstruction group moved more medially on the patella from 50° to 110° of flexion compared with the other conditions. The contact area showed no significant differences between the test conditions. After static MPFL reconstruction, the patellofemoral pressures in flexion angles from 60° to 110° were 3 to 5 times higher than those in the intact situation. The pressures after dynamic MPFL reconstruction were similar as compared with those in the intact situation, and therefore, dynamic MPFL reconstruction

  1. Anatomical reconstruction of the fourth brachymetatarsia with one-stage iliac bone and cartilage cap grafting.

    PubMed

    Woo, Sang Hyun; Bang, Chi Young; Ahn, Hee-Chan; Kim, Sung-Jung; Choi, Jun-Young

    2017-05-01

    We present a one-stage procedure for lengthening the fourth brachymetatarsia with autogenous iliac bone and cartilage cap grafting for the anatomical reconstruction of the metatarsophalangeal (MTP) joint METHODS: During the last 8 years, 56 feet in 41 patients with congenital brachymetatarsia of the fourth toe were corrected with a one-stage operation to reposition the articular cartilage cap to the distal part of interpositional iliac bone graft at the metatarsal epiphysis. The length of the harvested iliac bone graft was 22.9 mm on average. The mean fixation period was 58.5 days, and the mean gain in length and percentage increase was 20.9 mm and 39%, respectively. MRI showed a stable MTP joint over viable cartilage cap in 83.3% of the cases. Mean postoperative American Orthopedic Foot and Ankle Society lesser MTP-interphalangeal score was 82.0. Neither neurovascular impairment nor recurrence of brachymetatarsia occurred in the mean follow-up period of 43.6 months. All patients were satisfied with the postoperative cosmetic results. Thirteen patients (23.2%) complained of limited active dorsiflexion of the fourth toe, and extensor adhesion was released by extensor tenolysis in only one patient. In a single case of nonunion at the bone graft site, additional surgery was not necessary. Anatomical reconstruction of the fourth brachymetatarsia with one-stage interpositional iliac bone and cartilage cap grafting resulted in excellent cosmetic results and a physiologic MTP joint, providing the benefits of one-stage lengthening with a low complication rate. Therapeutic, IV. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  2. Combined 677CC/1298AC genotypes of methylenetetrahydrofolate reductase (MTHFR ) reduce susceptibility to precursor B lymphoblastic leukemia in a Chinese population.

    PubMed

    Lv, Ling; Wu, Cuie; Sun, Henjuan; Zhu, Saijuan; Yang, Yongchen; Chen, Xi; Fu, Hua; Bao, Liming

    2010-06-01

    The methylenetetrahydrofolate reductase (MTHFR) encodes a major enzyme in folate metabolism. It has been suggested that two MTHFR polymorphisms, 677C>T and 1298A>C, influence risk of acute lymphoblastic leukemia (ALL). Most studies on relation of MTHFR polymorphisms to ALL susceptibility have been in pediatric populations because ALL is relatively rare in adults. Here, we report a case-control study of 127 Chinese patients with adult precursor B lymphoblastic leukemia (B-ALL) to examine correlation between the MTHFR polymorphisms and B-ALL susceptibility in adults. Our data show that although the prevalence of genotype 1298CC was significantly higher in the female patients than in the controls (P = 0.04), the differences in distributions of combined genotypes of 1298CC with either 677CC or 677CT between the cases and the controls were statistically insignificant. Haplotype analysis revealed no significant difference between the cases and the controls. The prevalence for joint MTHFR genotypes 677CC/1298AC was significantly lower in the female B-ALL cases than in the controls [odds ratio (OR) = 0.06, 95% CI = 0.00-0.53, P = 0.0033] and no differences among the men [OR = 0.71, 95% CI = 0.20-2.53, P = 0.55], suggesting that protective effects of combined MTHFR 677CC/1298AC genotypes on susceptibility of adult B-ALL are gender bias toward women with 677CC/1298AC women being at a 17-fold reduced odds to develop B-ALL.

  3. From Beamline to Scanner with 225Ac

    NASA Astrophysics Data System (ADS)

    Robertson, Andrew K. H.; Ramogida, Caterina F.; Kunz, Peter; Rodriguez-Rodriguez, Cristina; Schaffer, Paul; Sossi, Vesna

    2016-09-01

    Due to the high linear energy transfer and short range of alpha-radiation, targeted radiation therapy using alpha-emitting pharmaceuticals that successfully target small disease clusters will kill target cells with limited harm to healthy tissue, potentially treating the most aggressive forms of cancer. As the parent of a decay chain with four alpha- and two beta-decays, 225Ac is a promising candidate for such a treatment. However, this requires retention of the entire decay chain at the target site, preventing the creation of freely circulating alpha-emitters that reduce therapeutic effect and increase toxicity to non-target tissues. Two major challenges to 225Ac pharmaceutical development exist: insufficient global supply, and the difficulty of preventing toxicity by retaining the entire decay chain at the target site. While TRIUMF works towards large-scale (C i amounts) production of 225Ac, we already use our Isotope Separation On-Line facility to provide small (< 1 mCi) quantities for in-house chemistry and imaging research that aims to improve and assess 225Ac radiopharmaceutical targeting. This presentation provides an overview of this research program and the journey of 225Ac from the beamline to the scanner. This research is funded by the Natural Sciences and Engineering Research Council of Canada.

  4. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered adjustable hospital bed. 880.5100... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered...

  5. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false AC-powered adjustable hospital bed. 880.5100... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered...

  6. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false AC-powered adjustable hospital bed. 880.5100... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered...

  7. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false AC-powered adjustable hospital bed. 880.5100... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered...

  8. A Case Study of Wind-PV-Thermal-Bundled AC/DC Power Transmission from a Weak AC Network

    NASA Astrophysics Data System (ADS)

    Xiao, H. W.; Du, W. J.; Wang, H. F.; Song, Y. T.; Wang, Q.; Ding, J.; Chen, D. Z.; Wei, W.

    2017-05-01

    Wind power generation and photovoltaic (PV) power generation bundled with the support by conventional thermal generation enables the generation controllable and more suitable for being sent over to remote load centre which are beneficial for the stability of weak sending end systems. Meanwhile, HVDC for long-distance power transmission is of many significant technique advantages. Hence the effects of wind-PV-thermal-bundled power transmission by AC/DC on power system have become an actively pursued research subject recently. Firstly, this paper introduces the technical merits and difficulties of wind-photovoltaic-thermal bundled power transmission by AC/DC systems in terms of meeting the requirement of large-scale renewable power transmission. Secondly, a system model which contains a weak wind-PV-thermal-bundled sending end system and a receiving end system in together with a parallel AC/DC interconnection transmission system is established. Finally, the significant impacts of several factors which includes the power transmission ratio between the DC and AC line, the distance between the sending end system and receiving end system, the penetration rate of wind power and the sending end system structure on system stability are studied.

  9. Computed tomography arthrography with traction in the human hip for three-dimensional reconstruction of cartilage and the acetabular labrum

    PubMed Central

    Henak, C.R.; Abraham, C.L.; Peters, C.L.; Sanders, R.K.; Weiss, J.A.; Anderson, A.E.

    2014-01-01

    AIM To develop and demonstrate the efficacy of a computed tomography arthrography (CTA) protocol for the hip that enables accurate three-dimensional reconstructions of cartilage and excellent visualization of the acetabular labrum. MATERIALS AND METHODS Ninety-three subjects were imaged (104 scans); 68 subjects with abnormal anatomy, 11 patients after periacetabular osteotomy surgery, and 25 subjects with normal anatomy. Fifteen to 25 ml of contrast agent diluted with lidocaine was injected using a lateral oblique approach. A Hare traction splint applied traction during CT. The association between traction force and intra-articular joint space was assessed qualitatively under fluoroscopy. Cartilage geometry was reconstructed from the CTA images for 30 subjects; the maximum joint space under traction was measured. RESULTS Using the Hare traction splint, the intra-articular space and boundaries of cartilage could be clearly delineated throughout the joint; the acetabular labrum was also visible. Dysplastic hips required less traction (~5 kg) than normal and retroverted hips required (>10 kg) to separate the cartilage. An increase in traction force produced a corresponding widening of the intra-articular joint space. Under traction, the maximum width of the intra-articular joint space during CT ranged from 0.98–6.7 mm (2.46 ± 1.16 mm). CONCLUSIONS When applied to subjects with normal and abnormal hip anatomy, the CTA protocol presented yields clear delineation of the cartilage and the acetabular labrum. Use of a Hare traction splint provides a simple, cost-effective method to widen the intra-articular joint space during CT, and provides flexibility to vary the traction as required. PMID:25070373

  10. Starch biosynthesis in cassava: a genome-based pathway reconstruction and its exploitation in data integration

    PubMed Central

    2013-01-01

    Background Cassava is a well-known starchy root crop utilized for food, feed and biofuel production. However, the comprehension underlying the process of starch production in cassava is not yet available. Results In this work, we exploited the recently released genome information and utilized the post-genomic approaches to reconstruct the metabolic pathway of starch biosynthesis in cassava using multiple plant templates. The quality of pathway reconstruction was assured by the employed parsimonious reconstruction framework and the collective validation steps. Our reconstructed pathway is presented in the form of an informative map, which describes all important information of the pathway, and an interactive map, which facilitates the integration of omics data into the metabolic pathway. Additionally, to demonstrate the advantage of the reconstructed pathways beyond just the schematic presentation, the pathway could be used for incorporating the gene expression data obtained from various developmental stages of cassava roots. Our results exhibited the distinct activities of the starch biosynthesis pathway in different stages of root development at the transcriptional level whereby the activity of the pathway is higher toward the development of mature storage roots. Conclusions To expand its applications, the interactive map of the reconstructed starch biosynthesis pathway is available for download at the SBI group’s website (http://sbi.pdti.kmutt.ac.th/?page_id=33). This work is considered a big step in the quantitative modeling pipeline aiming to investigate the dynamic regulation of starch biosynthesis in cassava roots. PMID:23938102

  11. Starch biosynthesis in cassava: a genome-based pathway reconstruction and its exploitation in data integration.

    PubMed

    Saithong, Treenut; Rongsirikul, Oratai; Kalapanulak, Saowalak; Chiewchankaset, Porntip; Siriwat, Wanatsanan; Netrphan, Supatcharee; Suksangpanomrung, Malinee; Meechai, Asawin; Cheevadhanarak, Supapon

    2013-08-10

    Cassava is a well-known starchy root crop utilized for food, feed and biofuel production. However, the comprehension underlying the process of starch production in cassava is not yet available. In this work, we exploited the recently released genome information and utilized the post-genomic approaches to reconstruct the metabolic pathway of starch biosynthesis in cassava using multiple plant templates. The quality of pathway reconstruction was assured by the employed parsimonious reconstruction framework and the collective validation steps. Our reconstructed pathway is presented in the form of an informative map, which describes all important information of the pathway, and an interactive map, which facilitates the integration of omics data into the metabolic pathway. Additionally, to demonstrate the advantage of the reconstructed pathways beyond just the schematic presentation, the pathway could be used for incorporating the gene expression data obtained from various developmental stages of cassava roots. Our results exhibited the distinct activities of the starch biosynthesis pathway in different stages of root development at the transcriptional level whereby the activity of the pathway is higher toward the development of mature storage roots. To expand its applications, the interactive map of the reconstructed starch biosynthesis pathway is available for download at the SBI group's website (http://sbi.pdti.kmutt.ac.th/?page_id=33). This work is considered a big step in the quantitative modeling pipeline aiming to investigate the dynamic regulation of starch biosynthesis in cassava roots.

  12. 21 CFR 888.1240 - AC-powered dynamometer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false AC-powered dynamometer. 888.1240 Section 888.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Diagnostic Devices § 888.1240 AC-powered dynamometer. (a...

  13. 21 CFR 888.1240 - AC-powered dynamometer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false AC-powered dynamometer. 888.1240 Section 888.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Diagnostic Devices § 888.1240 AC-powered dynamometer. (a...

  14. 21 CFR 888.1240 - AC-powered dynamometer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false AC-powered dynamometer. 888.1240 Section 888.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Diagnostic Devices § 888.1240 AC-powered dynamometer. (a...

  15. Chimpanzee ankle and foot joint kinematics: Arboreal versus terrestrial locomotion.

    PubMed

    Holowka, Nicholas B; O'Neill, Matthew C; Thompson, Nathan E; Demes, Brigitte

    2017-09-01

    Many aspects of chimpanzee ankle and midfoot joint morphology are believed to reflect adaptations for arboreal locomotion. However, terrestrial travel also constitutes a significant component of chimpanzee locomotion, complicating functional interpretations of chimpanzee and fossil hominin foot morphology. Here we tested hypotheses of foot motion and, in keeping with general assumptions, we predicted that chimpanzees would use greater ankle and midfoot joint ranges of motion during travel on arboreal supports than on the ground. We used a high-speed motion capture system to measure three-dimensional kinematics of the ankle and midfoot joints in two male chimpanzees during three locomotor modes: terrestrial quadrupedalism on a flat runway, arboreal quadrupedalism on a horizontally oriented tree trunk, and climbing on a vertically oriented tree trunk. Chimpanzees used relatively high ankle joint dorsiflexion angles during all three locomotor modes, although dorsiflexion was greatest in arboreal modes. They used higher subtalar joint coronal plane ranges of motion during terrestrial and arboreal quadrupedalism than during climbing, due in part to their use of high eversion angles in the former. Finally, they used high midfoot inversion angles during arboreal locomotor modes, but used similar midfoot sagittal plane kinematics across all locomotor modes. The results indicate that chimpanzees use large ranges of motion at their various ankle and midfoot joints during both terrestrial and arboreal locomotion. Therefore, we argue that chimpanzee foot anatomy enables a versatile locomotor repertoire, and urge caution when using foot joint morphology to reconstruct arboreal behavior in fossil hominins. © 2017 Wiley Periodicals, Inc.

  16. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered adjustable hospital bed. 880.5100 Section 880.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered...

  17. Nonlinear AC susceptibility, surface and bulk shielding

    NASA Astrophysics Data System (ADS)

    van der Beek, C. J.; Indenbom, M. V.; D'Anna, G.; Benoit, W.

    1996-02-01

    We calculate the nonlinear AC response of a thin superconducting strip in perpendicular field, shielded by an edge current due to the geometrical barrier. A comparison with the results for infinite samples in parallel field, screened by a surface barrier, and with those for screening by a bulk current in the critical state, shows that the AC response due to a barrier has general features that are independent of geometry, and that are significantly different from those for screening by a bulk current in the critical state. By consequence, the nonlinear (global) AC susceptibility can be used to determine the origin of magnetic irreversibility. A comparison with experiments on a Bi 2Sr 2CaCu 2O 8+δ crystal shows that in this material, the low-frequency AC screening at high temperature is mainly due to the screening by an edge current, and that this is the unique source of the nonlinear magnetic response at temperatures above 40 K.

  18. Errors and Uncertainties in Dose Reconstruction for Radiation Effects Research

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Strom, Daniel J.

    Dose reconstruction for studies of the health effects of ionizing radiation have been carried out for many decades. Major studies have included Japanese bomb survivors, atomic veterans, downwinders of the Nevada Test Site and Hanford, underground uranium miners, and populations of nuclear workers. For such studies to be credible, significant effort must be put into applying the best science to reconstructing unbiased absorbed doses to tissues and organs as a function of time. In many cases, more and more sophisticated dose reconstruction methods have been developed as studies progressed. For the example of the Japanese bomb survivors, the dose surrogatemore » “distance from the hypocenter” was replaced by slant range, and then by TD65 doses, DS86 doses, and more recently DS02 doses. Over the years, it has become increasingly clear that an equal level of effort must be expended on the quantitative assessment of uncertainty in such doses, and to reducing and managing uncertainty. In this context, this paper reviews difficulties in terminology, explores the nature of Berkson and classical uncertainties in dose reconstruction through examples, and proposes a path forward for Joint Coordinating Committee for Radiation Effects Research (JCCRER) Project 2.4 that requires a reasonably small level of effort for DOSES-2008.« less

  19. AC BREAKDOWN IN GASES

    DTIC Science & Technology

    electron- emission (multipactor) region, and (3) the low-frequency region. The breakdown mechanism in each of these regions is explained. An extensive bibliography on AC breakdown in gases is included.

  20. Assessing the allelotypic effect of two aminocyclopropane carboxylic acid synthase-encoding genes MdACS1 and MdACS3a on fruit ethylene production and softening in Malus

    PubMed Central

    Dougherty, Laura; Zhu, Yuandi; Xu, Kenong

    2016-01-01

    Phytohormone ethylene largely determines apple fruit shelf life and storability. Previous studies demonstrated that MdACS1 and MdACS3a, which encode 1-aminocyclopropane-1-carboxylic acid synthases (ACS), are crucial in apple fruit ethylene production. MdACS1 is well-known to be intimately involved in the climacteric ethylene burst in fruit ripening, while MdACS3a has been regarded a main regulator for ethylene production transition from system 1 (during fruit development) to system 2 (during fruit ripening). However, MdACS3a was also shown to have limited roles in initiating the ripening process lately. To better assess their roles, fruit ethylene production and softening were evaluated at five time points during a 20-day post-harvest period in 97 Malus accessions and in 34 progeny from 2 controlled crosses. Allelotyping was accomplished using an existing marker (ACS1) for MdACS1 and two markers (CAPS866 and CAPS870) developed here to specifically detect the two null alleles (ACS3a-G289V and Mdacs3a) of MdACS3a. In total, 952 Malus accessions were allelotyped with the three markers. The major findings included: The effect of MdACS1 was significant on fruit ethylene production and softening while that of MdACS3a was less detectable; allele MdACS1–2 was significantly associated with low ethylene and slow softening; under the same background of the MdACS1 allelotypes, null allele Mdacs3a (not ACS3a-G289V) could confer a significant delay of ethylene peak; alleles MdACS1–2 and Mdacs3a (excluding ACS3a-G289V) were highly enriched in M. domestica and M. hybrid when compared with those in M. sieversii. These findings are of practical implications in developing apples of low and delayed ethylene profiles by utilizing the beneficial alleles MdACS1-2 and Mdacs3a. PMID:27231553

  1. Implementation of Open and Closed Kinetic Chain Quadriceps Strengthening Exercises after Anterior Cruciate Ligament Reconstruction.

    ERIC Educational Resources Information Center

    Ross, Michael D.; Denegar, Craig R.; Winzenried, Jay A.

    2001-01-01

    Reviews the effects of open kinetic chain (OKC) and closed kinetic chain (CKC) exercise on anterior cruciate ligament (ACL) strain and patellofemoral joint stress, suggesting a combination of the two for quadriceps strengthening after ACL reconstruction. Both OKC and CKC exercises may be modified and implemented for quadriceps strengthening after…

  2. Truly anatomic coracoclavicular ligament reconstruction with 2 Endobutton devices for acute Rockwood type V acromioclavicular joint dislocations.

    PubMed

    Xue, Cheng; Song, Li-Jun; Zhang, Hao; Tang, Guo-Long; Li, Xiang; Fang, Jia-Hu

    2018-06-01

    Truly anatomic coracoclavicular ligament reconstruction (TACCR) according to the original insertions is a creative new method for the treatment of severe acromioclavicular separation. This research analyzed the clinical and radiologic results of TACCR in 25 patients with at least 2-year follow-up. The study enrolled 25 patients with Rockwood type V acromioclavicular joint dislocations who underwent TACCR using 2 Endobutton (Smith & Nephew Inc., Andover, MA, USA) devices from May 2013 to October 2015. Patients were assessed with clinical and radiologic follow-up at 3, 6, 12, 18, and 24 months postoperatively. The clinical assessments consisted of the visual analog scale and the Constant score. The radiographic evaluations were performed by measurements of the coracoclavicular distance. The mean follow-up was 34 ± 6.8 months (range, 24-48 months). The visual analog scale and Constant scores revealed significant advancements from 5 ± 0.9 (range, 4-7) and 45 ± 5.6 (range, 30-54) scores preoperatively to 0 ± 0.5 (range, 0-2) and 95 ± 2.9 (range, 91-98) scores at 24 months postoperatively, respectively. The coracoclavicular distance significantly decreased from 23 ± 5.4 mm (range, 16-34 mm) preoperatively to 8 ± 0.9 mm (range, 7-10 mm) at the final follow-up. TACCR represents a safe, reliable and creative surgical technique that yields good to excellent clinical and radiologic outcomes in the treatment of severe acromioclavicular separation. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  3. Virtual reconstruction of the Neanderthal Amud 1 cranium.

    PubMed

    Amano, Hideki; Kikuchi, Takeo; Morita, Yusuke; Kondo, Osamu; Suzuki, Hiromasa; Ponce de León, Marcia S; Zollikofer, Christoph P E; Bastir, Markus; Stringer, Chris; Ogihara, Naomichi

    2015-10-01

    We describe a new computer reconstruction to obtain complete anatomical information of the ecto- and endocranium from the imperfectly preserved skull of the Neanderthal Amud 1. Data were obtained from computed tomography scans of the fossil cranium. Adhesive and plaster were then virtually removed from the original specimen, and the fragments comprising the fossil cranium were separated. These fragments were then mathematically reassembled based on the smoothness of the joints. Both sides of the cranium were reassembled separately, and then aligned based on bilateral symmetry and the distance between the mandibular fossae obtained from the associated mandible. The position of the isolated maxilla was determined based on the position of the mandible that was anatomically articulated to the mandibular fossae. To restore missing basicranial and damaged endocranial regions, the cranium of Forbes' Quarry 1 was warped onto that of La Chapelle-aux-Saints 1, and the resulting composite Neanderthal cranium was then warped onto the reconstructed Amud 1 by an iterative thin-plate spline deformation. Comparison of the computer reconstruction with the original indicated that the newly reconstructed Amud 1 cranium was slightly shorter and wider in the anteroposterior and mediolateral directions, respectively, suggesting that it was relatively more brachycephalic. The endocranial volume was estimated to be 1,736 cm 3 , which was quite similar to the original estimated value of 1,740 cm 3 . This new computer reconstruction enables not only measurement of new cranial metrics, but also inclusion of the Amud 1 specimen in three-dimensional geometric morphometric analyses that were previously difficult due to its incompleteness. Am J Phys Anthropol 158:185-197, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  4. Use of synthetic ligament in reconstruction after massive bone tumour removal.

    PubMed

    Allington, Nanni J; Rondia, Jean

    2012-04-01

    With advances in medical imaging over the past decades and with a multidisciplinary approach in bone tumour management, limb sparing procedures are more often feasible but come with new challenges. One of these is to deal with the remaining soft tissues, especially muscles, or bony parts and to restore continuity and a correct function. Synthetic ligaments have been used safely for several decades in various ligament reconstruction procedures with good results. We present a technique in which a synthetic ligament is used to augment or replace a joint capsule around a megaprosthesis. The joint is thus stabilized, and the remaining bony parts and muscles are attached to the synthetic material to restore continuity and allow better function of the spared limb.

  5. Kinematics of ACL and anterolateral ligament. Part II: anterolateral and anterior cruciate ligament reconstruction.

    PubMed

    Bonanzinga, T; Signorelli, C; Grassi, A; Lopomo, N; Jain, M; Mosca, M; Iacono, F; Marcacci, M; Zaffagnini, S

    2017-04-01

    To quantify the influence of Single-Bundle with Lateral Plasty and Double-Bundle reconstruction on static and dynamic laxity in combined ACL- and ALL-deficient knees. The study included 10 fresh-frozen human knees. The joints were analyzed in the following conditions: ACL + ALL resection, Single-Bundle with Lateral Plasty (SBLP) reconstruction, Double-Bundle (DB) reconstruction. Testing parameters were: anterior displacement at 30° and 90° of flexion (AP30, AP90) applying a manual maximum load; internal rotation at 30° and 90° of flexion (INT30, INT90) applying a 5 Nm torque and acceleration and internal rotation Pivot-Shift (PS) test. Kinematics was acquired by a navigation system. Paired Student's t test was conducted to assess statistical difference (P < 0.05). At both 30° and 90° of knee flexion, both SBLP and DB surgical techniques showed a significant reduction (P < 0.01) of anterior-posterior tibial displacement compared to the resection of ACL + ALL. At 30° on knee flexion it is the SBLP that allows the greatest reduction of internal rotational laxity when compared to DB reconstruction. Concerning the PS test, only SBPL procedure had a significant laxity decrease considering the acceleration reached by the joint when compared with the ACL + ALL state (P < 0.01). Clinical relevance of this study is that the internal rotation and PS test were more efficiently controlled by the SBLP technique than by the DB one at both 30° and 90° of flexion in case of ACL + ALL lesions.

  6. Successful enrichment of the ubiquitous freshwater acI Actinobacteria.

    PubMed

    Garcia, Sarahi L; McMahon, Katherine D; Grossart, Hans-Peter; Warnecke, Falk

    2014-02-01

    Actinobacteria of the acI lineage are often the numerically dominant bacterial phylum in surface freshwaters, where they can account for > 50% of total bacteria. Despite their abundance, there are no described isolates. In an effort to obtain enrichment of these ubiquitous freshwater Actinobacteria, diluted freshwater samples from Lake Grosse Fuchskuhle, Germany, were incubated in 96-well culture plates. With this method, a successful enrichment containing high abundances of a member of the lineage acI was established. Phylogenetic classification showed that the acI Actinobacteria of the enrichment belonged to the acI-B2 tribe, which seems to prefer acidic lakes. This enrichment grows to low cell densities and thus the oligotrophic nature of acI-B2 was confirmed. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  7. A variational reconstruction method for undersampled dynamic x-ray tomography based on physical motion models

    NASA Astrophysics Data System (ADS)

    Burger, Martin; Dirks, Hendrik; Frerking, Lena; Hauptmann, Andreas; Helin, Tapio; Siltanen, Samuli

    2017-12-01

    In this paper we study the reconstruction of moving object densities from undersampled dynamic x-ray tomography in two dimensions. A particular motivation of this study is to use realistic measurement protocols for practical applications, i.e. we do not assume to have a full Radon transform in each time step, but only projections in few angular directions. This restriction enforces a space-time reconstruction, which we perform by incorporating physical motion models and regularization of motion vectors in a variational framework. The methodology of optical flow, which is one of the most common methods to estimate motion between two images, is utilized to formulate a joint variational model for reconstruction and motion estimation. We provide a basic mathematical analysis of the forward model and the variational model for the image reconstruction. Moreover, we discuss the efficient numerical minimization based on alternating minimizations between images and motion vectors. A variety of results are presented for simulated and real measurement data with different sampling strategy. A key observation is that random sampling combined with our model allows reconstructions of similar amount of measurements and quality as a single static reconstruction.

  8. Simultaneous prediction of enzyme orthologs from chemical transformation patterns for de novo metabolic pathway reconstruction

    PubMed Central

    Tabei, Yasuo; Yamanishi, Yoshihiro; Kotera, Masaaki

    2016-01-01

    Motivation: Metabolic pathways are an important class of molecular networks consisting of compounds, enzymes and their interactions. The understanding of global metabolic pathways is extremely important for various applications in ecology and pharmacology. However, large parts of metabolic pathways remain unknown, and most organism-specific pathways contain many missing enzymes. Results: In this study we propose a novel method to predict the enzyme orthologs that catalyze the putative reactions to facilitate the de novo reconstruction of metabolic pathways from metabolome-scale compound sets. The algorithm detects the chemical transformation patterns of substrate–product pairs using chemical graph alignments, and constructs a set of enzyme-specific classifiers to simultaneously predict all the enzyme orthologs that could catalyze the putative reactions of the substrate–product pairs in the joint learning framework. The originality of the method lies in its ability to make predictions for thousands of enzyme orthologs simultaneously, as well as its extraction of enzyme-specific chemical transformation patterns of substrate–product pairs. We demonstrate the usefulness of the proposed method by applying it to some ten thousands of metabolic compounds, and analyze the extracted chemical transformation patterns that provide insights into the characteristics and specificities of enzymes. The proposed method will open the door to both primary (central) and secondary metabolism in genomics research, increasing research productivity to tackle a wide variety of environmental and public health matters. Availability and Implementation: Contact: maskot@bio.titech.ac.jp PMID:27307627

  9. Three-dimensional Reconstruction of Scar Contracture-bearing Axilla and Digital Webs Using the Square Flap Method.

    PubMed

    Huang, Chenyu; Ogawa, Rei

    2014-05-01

    Joint scar contractures are characterized by tight bands of soft tissue that bridge the 2 ends of the joint like a web. Classical treatment methods such as Z-plasties are mainly based on 2-dimensional designs. Our square flap method is an alternative surgical method that restores the span of the web in a stereometric fashion, thereby reconstructing joint function. In total, 20 Japanese patients with joint scar contractures on the axillary (n = 10) or first digital web (n = 10) underwent square flap surgery. The maximum range of motion and commissure length were measured before and after surgery. A theoretical stereometric geometrical model of the square flap was established to compare it to the classical single (60 degree), 4-flap (45 degree), and 5-flap (60 degree) Z-plasties in terms of theoretical web reconstruction efficacy. All cases achieved 100% contracture release. The maximum range of motion and web space improved after square flap surgery (P = 0.001). Stereometric geometrical modeling revealed that the standard square flap (α = 45 degree; β = 90 degree) yields a larger flap area, length/width ratio, and postsurgical commissure length than the Z-plasties. It can also be adapted by varying angles α and β, although certain angle thresholds must be met to obtain the stereometric advantages of this method. When used to treat joint scar contractures, the square flap method can fully span the web space in a stereometric manner, thus yielding a close-to-original shape and function. Compared with the classical Z-plasties, it also provides sufficient anatomical blood supply while imposing the least physiological tension on the adjacent skin.

  10. Three-dimensional Reconstruction of Scar Contracture-bearing Axilla and Digital Webs Using the Square Flap Method

    PubMed Central

    Huang, Chenyu

    2014-01-01

    Background: Joint scar contractures are characterized by tight bands of soft tissue that bridge the 2 ends of the joint like a web. Classical treatment methods such as Z-plasties are mainly based on 2-dimensional designs. Our square flap method is an alternative surgical method that restores the span of the web in a stereometric fashion, thereby reconstructing joint function. Methods: In total, 20 Japanese patients with joint scar contractures on the axillary (n = 10) or first digital web (n = 10) underwent square flap surgery. The maximum range of motion and commissure length were measured before and after surgery. A theoretical stereometric geometrical model of the square flap was established to compare it to the classical single (60 degree), 4-flap (45 degree), and 5-flap (60 degree) Z-plasties in terms of theoretical web reconstruction efficacy. Results: All cases achieved 100% contracture release. The maximum range of motion and web space improved after square flap surgery (P = 0.001). Stereometric geometrical modeling revealed that the standard square flap (α = 45 degree; β = 90 degree) yields a larger flap area, length/width ratio, and postsurgical commissure length than the Z-plasties. It can also be adapted by varying angles α and β, although certain angle thresholds must be met to obtain the stereometric advantages of this method. Conclusions: When used to treat joint scar contractures, the square flap method can fully span the web space in a stereometric manner, thus yielding a close-to-original shape and function. Compared with the classical Z-plasties, it also provides sufficient anatomical blood supply while imposing the least physiological tension on the adjacent skin. PMID:25289342

  11. Design and preliminary biomechanical analysis of artificial cervical joint complex.

    PubMed

    Jian, Yu; Lan-Tao, Liu; Zhao, Jian-ning; Jian-ning, Zhao

    2013-06-01

    To design an artificial cervical joint complex (ACJC) prosthesis for non-fusion reconstruction after cervical subtotal corpectomy, and to evaluate the biomechanical stability, preservation of segment movements and influence on adjacent inter-vertebral movements of this prosthesis. The prosthesis was composed of three parts: the upper/lower joint head and the middle artificial vertebrae made of Cobalt-Chromium-Molybdenum (Co-Cr-Mo) alloy and polyethylene with a ball-and-socket joint design resembling the multi-axial movement in normal inter-vertebral spaces. Biomechanical tests of intact spine (control), Orion locking plate system and ACJC prosthesis were performed on formalin-fixed cervical spine specimens from 21 healthy cadavers to compare stability, range of motion (ROM) of the surgical segment and ROM of adjacent inter-vertebral spaces. As for stability of the whole lower cervical spine, there was no significant difference of flexion, extension, lateral bending and torsion between intact spine group and ACJC prosthesis group. As for segment movements, difference in flexion, lateral bending or torsion between ACJC prosthesis group and control group was not statistically significant, while ACJC prosthesis group showed an increase in extension (P < 0.05) compared to that of the control group. In addition, ACJC prosthesis group demonstrated better flexion, extension and lateral bending compared to those of Orion plating system group (P < 0.05). Difference in adjacent inter-vertebral ROM of the ACJC prosthesis group was not statistically significant compared to that of the control group. After cervical subtotal corpectomy, reconstruction with ACJC prosthesis not only obtained instant stability, but also reserved segment motions effectively, without abnormal gain of mobility at adjacent inter-vertebral spaces.

  12. Dynamic optical imaging of vascular and metabolic reactivity in rheumatoid joints.

    PubMed

    Lasker, Joseph M; Fong, Christopher J; Ginat, Daniel T; Dwyer, Edward; Hielscher, Andreas H

    2007-01-01

    Dynamic optical imaging is increasingly applied to clinically relevant areas such as brain and cancer imaging. In this approach, some external stimulus is applied and changes in relevant physiological parameters (e.g., oxy- or deoxyhemoglobin concentrations) are determined. The advantage of this approach is that the prestimulus state can be used as a reference or baseline against which the changes can be calibrated. Here we present the first application of this method to the problem of characterizing joint diseases, especially effects of rheumatoid arthritis (RA) in the proximal interphalangeal finger joints. Using a dual-wavelength tomographic imaging system together with previously implemented model-based iterative image reconstruction schemes, we have performed initial dynamic imaging case studies on a limited number of healthy volunteers and patients diagnosed with RA. Focusing on three cases studies, we illustrated our major finds. These studies support our hypothesis that differences in the vascular reactivity exist between affected and unaffected joints.

  13. A Novel 2D Image Compression Algorithm Based on Two Levels DWT and DCT Transforms with Enhanced Minimize-Matrix-Size Algorithm for High Resolution Structured Light 3D Surface Reconstruction

    NASA Astrophysics Data System (ADS)

    Siddeq, M. M.; Rodrigues, M. A.

    2015-09-01

    Image compression techniques are widely used on 2D image 2D video 3D images and 3D video. There are many types of compression techniques and among the most popular are JPEG and JPEG2000. In this research, we introduce a new compression method based on applying a two level discrete cosine transform (DCT) and a two level discrete wavelet transform (DWT) in connection with novel compression steps for high-resolution images. The proposed image compression algorithm consists of four steps. (1) Transform an image by a two level DWT followed by a DCT to produce two matrices: DC- and AC-Matrix, or low and high frequency matrix, respectively, (2) apply a second level DCT on the DC-Matrix to generate two arrays, namely nonzero-array and zero-array, (3) apply the Minimize-Matrix-Size algorithm to the AC-Matrix and to the other high-frequencies generated by the second level DWT, (4) apply arithmetic coding to the output of previous steps. A novel decompression algorithm, Fast-Match-Search algorithm (FMS), is used to reconstruct all high-frequency matrices. The FMS-algorithm computes all compressed data probabilities by using a table of data, and then using a binary search algorithm for finding decompressed data inside the table. Thereafter, all decoded DC-values with the decoded AC-coefficients are combined in one matrix followed by inverse two levels DCT with two levels DWT. The technique is tested by compression and reconstruction of 3D surface patches. Additionally, this technique is compared with JPEG and JPEG2000 algorithm through 2D and 3D root-mean-square-error following reconstruction. The results demonstrate that the proposed compression method has better visual properties than JPEG and JPEG2000 and is able to more accurately reconstruct surface patches in 3D.

  14. 21 CFR 880.5510 - Non-AC-powered patient lift.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Non-AC-powered patient lift. 880.5510 Section 880... Devices § 880.5510 Non-AC-powered patient lift. (a) Identification. A non-AC-powered patient lift is a hydraulic, battery, or mechanically powered device, either fixed or mobile, used to lift and transport a...

  15. 21 CFR 880.5510 - Non-AC-powered patient lift.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Non-AC-powered patient lift. 880.5510 Section 880... Devices § 880.5510 Non-AC-powered patient lift. (a) Identification. A non-AC-powered patient lift is a hydraulic, battery, or mechanically powered device, either fixed or mobile, used to lift and transport a...

  16. Nuclear structure of 231Ac

    NASA Astrophysics Data System (ADS)

    Boutami, R.; Borge, M. J. G.; Mach, H.; Kurcewicz, W.; Fraile, L. M.; Gulda, K.; Aas, A. J.; García-Raffi, L. M.; Løvhøiden, G.; Martínez, T.; Rubio, B.; Taín, J. L.; Tengblad, O.

    2008-10-01

    The low-energy structure of 231Ac has been investigated by means of γ ray spectroscopy following the β decay of 231Ra. Multipolarities of 28 transitions have been established by measuring conversion electrons with a MINI-ORANGE electron spectrometer. The decay scheme of 231Ra → 231Ac has been constructed for the first time. The Advanced Time Delayed βγγ(t) method has been used to measure the half-lives of five levels. The moderately fast B(E1) transition rates derived suggest that the octupole effects, albeit weak, are still present in this exotic nucleus.

  17. Autographa californica multiple nucleopolyhedrovirus ac53 plays a role in nucleocapsid assembly

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu Chao; Li Zhaofei; Wu Wenbi

    2008-12-05

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) orf53 (ac53) is a highly conserved gene existing in all sequenced Lepidoptera and Hymenoptera baculoviruses, but its function remains unknown. To investigate its role in the baculovirus life cycle, an ac53 deletion virus (vAc{sup ac53KO-PH-GFP}) was generated through homologous recombination in Escherichia coli. Fluorescence and light microscopy and titration analysis revealed that vAc{sup ac53KO-PH-GFP} could not produce infectious budded virus in infected Sf9 cells. Real-time PCR demonstrated that the ac53 deletion did not affect the levels of viral DNA replication. Electron microscopy showed that many lucent tubular shells devoid of the nucleoprotein core are presentmore » in the virogenic stroma and ring zone, indicating that the ac53 knockout affected nucleocapsid assembly. With a recombinant virus expressing an Ac53-GFP fusion protein, we observed that Ac53 was distributed within the cytoplasm and nucleus at 24 h post-infection, but afterwards accumulated predominantly near the nucleus-cytoplasm boundary. These data demonstrate that ac53 is involved in nucleocapsid assembly and is an essential gene for virus production.« less

  18. Biomechanics of the incudo-malleolar-joint - Experimental investigations for quasi-static loads.

    PubMed

    Ihrle, S; Gerig, R; Dobrev, I; Röösli, C; Sim, J H; Huber, A M; Eiber, A

    2016-10-01

    Under large quasi-static loads, the incudo-malleolar joint (IMJ), connecting the malleus and the incus, is highly mobile. It can be classified as a mechanical filter decoupling large quasi-static motions while transferring small dynamic excitations. This is presumed to be due to the complex geometry of the joint inducing a spatial decoupling between the malleus and incus under large quasi-static loads. Spatial Laser Doppler Vibrometer (LDV) displacement measurements on isolated malleus-incus-complexes (MICs) were performed. With the malleus firmly attached to a probe holder, the incus was excited by applying quasi-static forces at different points. For each force application point the resulting displacement was measured subsequently at different points on the incus. The location of the force application point and the LDV measurement points were calculated in a post-processing step combining the position of the LDV points with geometric data of the MIC. The rigid body motion of the incus was then calculated from the multiple displacement measurements for each force application point. The contact regions of the articular surfaces for different load configurations were calculated by applying the reconstructed motion to the geometry model of the MIC and calculate the minimal distance of the articular surfaces. The reconstructed motion has a complex spatial characteristic and varies for different force application points. The motion changed with increasing load caused by the kinematic guidance of the articular surfaces of the joint. The IMJ permits a relative large rotation around the anterior-posterior axis through the joint when a force is applied at the lenticularis in lateral direction before impeding the motion. This is part of the decoupling of the malleus motion from the incus motion in case of large quasi-static loads. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Complex posterior thoracic wall reconstruction using a crossover combined latissimus dorsi and serratus anterior free flap.

    PubMed

    Bodin, Frédéric; Dissaux, Caroline; Steib, Jean-Paul; Massard, Gilbert

    2016-03-01

    Radical resection of an extended malignant sarcoma of the chest wall requires full-thickness thoracic chest wall reconstruction. Reconstruction is tedious in the case of posteriorly located tumours, because the ipsilateral pedicled myocutaneous latissimus dorsi flap is involved and hence not usable for soft tissue coverage. We report an original case of a left giant dorsal chondrosarcoma originating from the 11th costovertebral joint. After extended resection and skeletal reconstruction, soft tissue coverage was achieved with an original contralateral free flap encompassing both latissimus dorsi and serratus anterior muscles. The flap pedicle was anastomosed to the ipsilateral thoracodorsal vessels. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  20. Single-limb drop landing biomechanics in active individuals with and without a history of anterior cruciate ligament reconstruction: A total support analysis.

    PubMed

    Pozzi, Federico; Di Stasi, Stephanie; Zeni, Joseph A; Barrios, Joaquin A

    2017-03-01

    The purpose of this study was to characterize the magnitude and distribution of the total support moment during single-limb drop landings in individuals after anterior cruciate ligament reconstruction compared to a control group. Twenty participants after reconstruction and twenty control participants matched on sex, limb dominance and activity level were recruited. Motion analysis was performed during a single-limb drop landing task. Total support moment was determined by summing the internal extensor moments at the ankle, knee, and hip. Each relative joint contribution to the total support moment was calculated by dividing each individual contribution by the total support moment. Data were captured during a landing interval that started at initial contact and ended at the lowest vertical position of the pelvis. Data were then time-normalized and indexed at 25, 50, 75, and 100% of the landing interval. No between-group differences for total support moment magnitude were observed. At both 75% and 100% of the landing, the relative contribution of the knee joint was lower in those with a history of surgery (p<0.001). At the same instances, the relative contribution to the total support moment by the hip joint was greater in those with a history of surgery (p=0.004). In active participants after anterior cruciate ligament reconstruction, relative contributions to anti-gravity support of the center of mass shifted from the knee to the hip joint during single-limb landing, which became evident towards the end of the landing interval. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Low-dose 4D cone-beam CT via joint spatiotemporal regularization of tensor framelet and nonlocal total variation

    NASA Astrophysics Data System (ADS)

    Han, Hao; Gao, Hao; Xing, Lei

    2017-08-01

    Excessive radiation exposure is still a major concern in 4D cone-beam computed tomography (4D-CBCT) due to its prolonged scanning duration. Radiation dose can be effectively reduced by either under-sampling the x-ray projections or reducing the x-ray flux. However, 4D-CBCT reconstruction under such low-dose protocols is prone to image artifacts and noise. In this work, we propose a novel joint regularization-based iterative reconstruction method for low-dose 4D-CBCT. To tackle the under-sampling problem, we employ spatiotemporal tensor framelet (STF) regularization to take advantage of the spatiotemporal coherence of the patient anatomy in 4D images. To simultaneously suppress the image noise caused by photon starvation, we also incorporate spatiotemporal nonlocal total variation (SNTV) regularization to make use of the nonlocal self-recursiveness of anatomical structures in the spatial and temporal domains. Under the joint STF-SNTV regularization, the proposed iterative reconstruction approach is evaluated first using two digital phantoms and then using physical experiment data in the low-dose context of both under-sampled and noisy projections. Compared with existing approaches via either STF or SNTV regularization alone, the presented hybrid approach achieves improved image quality, and is particularly effective for the reconstruction of low-dose 4D-CBCT data that are not only sparse but noisy.

  2. Accurate 3D reconstruction of bony surfaces using ultrasonic synthetic aperture techniques for robotic knee arthroplasty.

    PubMed

    Kerr, William; Rowe, Philip; Pierce, Stephen Gareth

    2017-06-01

    Robotically guided knee arthroplasty systems generally require an individualized, preoperative 3D model of the knee joint. This is typically measured using Computed Tomography (CT) which provides the required accuracy for preoperative surgical intervention planning. Ultrasound imaging presents an attractive alternative to CT, allowing for reductions in cost and the elimination of doses of ionizing radiation, whilst maintaining the accuracy of the 3D model reconstruction of the joint. Traditional phased array ultrasound imaging methods, however, are susceptible to poor resolution and signal to noise ratios (SNR). Alleviating these weaknesses by offering superior focusing power, synthetic aperture methods have been investigated extensively within ultrasonic non-destructive testing. Despite this, they have yet to be fully exploited in medical imaging. In this paper, the ability of a robotic deployed ultrasound imaging system based on synthetic aperture methods to accurately reconstruct bony surfaces is investigated. Employing the Total Focussing Method (TFM) and the Synthetic Aperture Focussing Technique (SAFT), two samples were imaged which were representative of the bones of the knee joint: a human-shaped, composite distal femur and a bovine distal femur. Data were captured using a 5MHz, 128 element 1D phased array, which was manipulated around the samples using a robotic positioning system. Three dimensional surface reconstructions were then produced and compared with reference models measured using a precision laser scanner. Mean errors of 0.82mm and 0.88mm were obtained for the composite and bovine samples, respectively, thus demonstrating the feasibility of the approach to deliver the sub-millimetre accuracy required for the application. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  3. Optimization of spin-torque switching using AC and DC pulses

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dunn, Tom; Kamenev, Alex; Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455

    2014-06-21

    We explore spin-torque induced magnetic reversal in magnetic tunnel junctions using combined AC and DC spin-current pulses. We calculate the optimal pulse times and current strengths for both AC and DC pulses as well as the optimal AC signal frequency, needed to minimize the Joule heat lost during the switching process. The results of this optimization are compared against numeric simulations. Finally, we show how this optimization leads to different dynamic regimes, where switching is optimized by either a purely AC or DC spin-current, or a combination AC/DC spin-current, depending on the anisotropy energies and the spin-current polarization.

  4. Effect of ACL graft material on joint forces during a simulated in vivo motion in the porcine knee: examining force during the initial cycles.

    PubMed

    Boguszewski, Daniel V; Wagner, Christopher T; Butler, David L; Shearn, Jason T

    2014-11-01

    This study compared three-dimensional forces in knees containing anterior cruciate ligament (ACL) graft materials versus the native porcine ACL. A six-degree-of-freedom (DOF) robot simulated gait while recording the joint forces and moments. Knees were subjected to 10 cycles of simulated gait in intact, ACL-deficient, and ACL-reconstructed knee states to examine time zero biomechanical performance. Reconstruction was performed using bone-patellar tendon-bone allograft (BPTB), reconstructive porcine tissue matrix (RTM), and an RTM-polymer hybrid (Hybrid). Forces and moments were examined about anatomic DOFs throughout the gait cycle and at three key points during gait: heel strike (HS), mid stance (MS), toe off (TO). Compared to native ACL, each graft restored antero-posterior (A-P) forces throughout gait. However, all failed to mimic normal joint forces in other DOFs. For example, each reconstructed knee showed greater compressive forces at HS and TO compared to the native ACL knee. Overall, the Hybrid graft restored more of the native ACL forces following reconstruction than did BPTB, while RTM grafts were the least successful. If early onset osteoarthritis is in part caused by altered knee kinematics, then understanding how reconstruction materials restore critical force generation during gait is an essential step in improving a patient's long-term prognosis. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  5. Hip Strength in Patients with Quadriceps Strength Deficits after ACL Reconstruction.

    PubMed

    Bell, David R; Trigsted, Stephanie M; Post, Eric G; Walden, Courtney E

    2016-10-01

    Quadriceps strength deficits persist for years after anterior cruciate ligament (ACL) reconstruction, and patients with these deficits often shift torque demands away from the knee extensors to the hip during functional tasks. However, it is not clear how quadriceps strength deficits may affect hip strength. Therefore, the purpose of this study was to investigate differences in lower extremity strength in individuals with ACL reconstruction with differing levels of quadriceps strength asymmetry. Isometric strength was recorded bilaterally in 135 participants (73 control and 62 with unilateral ACL reconstruction, time from surgery = 30.9 ± 17.6 months) from the knee extensors and flexors, hip extensors and abductors, and hip internal and external rotator muscle groups. Symmetry indices (limb symmetry index (LSI)) were created based on quadriceps strength, and subjects with ACL reconstruction were subdivided (high quadriceps (LSI ≥ 90%), n = 37; low quadriceps (LSI < 85%), n = 18). Individual group (control vs high quadriceps vs low quadriceps) by limb (reconstructed/nondominant vs healthy/dominant) repeated-measures ANOVA was used to compare strength (%BW) for each of the six joint motions of interest (knee extensors/flexors, hip abductors/extensors/external, and internal rotators) while controlling for time from surgery. An interaction was observed for quadriceps strength (P < 0.001), and the reconstructed limb in the low quadriceps group was weaker than all other limbs. A main effect for group was observed with the low quadriceps group having greater hip extension (P = 0.007) strength in both limbs compared with the other groups. Knee flexion strength was weaker in the reconstructed limb of the high quadriceps group (P = 0.047) compared with all other groups and limbs. Individuals with ACL reconstruction and involved limb quadriceps weakness have greater hip extension strength in both limbs compared with patients with bilateral strength symmetry and controls.

  6. AC power generation from microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Lobo, Fernanda Leite; Wang, Heming; Forrestal, Casey; Ren, Zhiyong Jason

    2015-11-01

    Microbial fuel cells (MFCs) directly convert biodegradable substrates to electricity and carry good potential for energy-positive wastewater treatment. However, the low and direct current (DC) output from MFC is not usable for general electronics except small sensors, yet commercial DC-AC converters or inverters used in solar systems cannot be directly applied to MFCs. This study presents a new DC-AC converter system for MFCs that can generate alternating voltage in any desired frequency. Results show that AC power can be easily achieved in three different frequencies tested (1, 10, 60 Hz), and no energy storage layer such as capacitors was needed. The DC-AC converter efficiency was higher than 95% when powered by either individual MFCs or simple MFC stacks. Total harmonic distortion (THD) was used to investigate the quality of the energy, and it showed that the energy could be directly usable for linear electronic loads. This study shows that through electrical conversion MFCs can be potentially used in household electronics for decentralized off-grid communities.

  7. Joint feedback analysis modeling of nonesterified fatty acids in obese Zucker rats and normal Sprague-Dawley rats after different routes of administration of nicotinic acid.

    PubMed

    Tapani, Sofia; Almquist, Joachim; Leander, Jacob; Ahlström, Christine; Peletier, Lambertus A; Jirstrand, Mats; Gabrielsson, Johan

    2014-08-01

    Data were pooled from several studies on nicotinic acid (NiAc) intervention of fatty acid turnover in normal Sprague-Dawley and obese Zucker rats in order to perform a joint PKPD of data from more than 100 normal Sprague-Dawley and obese Zucker rats, exposed to several administration routes and rates. To describe the difference in pharmacodynamic parameters between obese and normal rats, we modified a previously published nonlinear mixed effects model describing tolerance and oscillatory rebound effects of NiAc on nonesterified fatty acids plasma concentrations. An important conclusion is that planning of experiments and dose scheduling cannot rely on pilot studies on normal animals alone. The obese rats have a less-pronounced concentration-response relationship and need higher doses to exhibit desired response. The relative level of fatty acid rebound after cessation of NiAc administration was also quantified in the two rat populations. Building joint normal-disease models with scaling parameter(s) to characterize the "degree of disease" can be a useful tool when designing informative experiments on diseased animals, particularly in the preclinical screen. Data were analyzed using nonlinear mixed effects modeling, for the optimization, we used an improved method for calculating the gradient than the usually adopted finite difference approximation. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  8. A Single-Phase Embedded Z-Source DC-AC Inverter

    PubMed Central

    Kim, Se-Jin; Lim, Young-Cheol

    2014-01-01

    In the conventional DC-AC inverter consisting of two DC-DC converters with unipolar output capacitors, the output capacitor voltages of the DC-DC converters must be higher than the DC input voltage. To overcome this weakness, this paper proposes a single-phase DC-AC inverter consisting of two embedded Z-source converters with bipolar output capacitors. The proposed inverter is composed of two embedded Z-source converters with a common DC source and output AC load. Though the output capacitor voltages of the converters are relatively low compared to those of a conventional inverter, an equivalent level of AC output voltages can be obtained. Moreover, by controlling the output capacitor voltages asymmetrically, the AC output voltage of the proposed inverter can be higher than the DC input voltage. To verify the validity of the proposed inverter, experiments were performed with a DC source voltage of 38 V. By controlling the output capacitor voltages of the converters symmetrically or asymmetrically, the proposed inverter can produce sinusoidal AC output voltages. The experiments show that efficiencies of up to 95% and 97% can be achieved with the proposed inverter using symmetric and asymmetric control, respectively. PMID:25133241

  9. A single-phase embedded Z-source DC-AC inverter.

    PubMed

    Kim, Se-Jin; Lim, Young-Cheol

    2014-01-01

    In the conventional DC-AC inverter consisting of two DC-DC converters with unipolar output capacitors, the output capacitor voltages of the DC-DC converters must be higher than the DC input voltage. To overcome this weakness, this paper proposes a single-phase DC-AC inverter consisting of two embedded Z-source converters with bipolar output capacitors. The proposed inverter is composed of two embedded Z-source converters with a common DC source and output AC load. Though the output capacitor voltages of the converters are relatively low compared to those of a conventional inverter, an equivalent level of AC output voltages can be obtained. Moreover, by controlling the output capacitor voltages asymmetrically, the AC output voltage of the proposed inverter can be higher than the DC input voltage. To verify the validity of the proposed inverter, experiments were performed with a DC source voltage of 38 V. By controlling the output capacitor voltages of the converters symmetrically or asymmetrically, the proposed inverter can produce sinusoidal AC output voltages. The experiments show that efficiencies of up to 95% and 97% can be achieved with the proposed inverter using symmetric and asymmetric control, respectively.

  10. Robert Jones Lecture, 1979. The reconstructive surgery of flaccid paralysis.

    PubMed Central

    Brooks, D.

    1982-01-01

    A flaccid paralysis results from damage to any part of the lower motor neurone, from destruction of the anterior horn cell by poliomyelitis to injury of the peripheral axon by trauma or disease. Reconstructive surgery can do much to alleviate the residual paralysis. The indications and timing for surgery are considered. Certain well-tried operative techniques are described, from tendon transplantation to arthrodeses of joints, and the relative merits of each procedure are evaluated and placed in perspective. PMID:7092088

  11. Post-Flash Validation of the new ACS/WFC Subarrays

    NASA Astrophysics Data System (ADS)

    Bellini, A.; Grogin, N. A.; Lim, P. L.; Golimowski, D.

    2017-05-01

    We made use of the new ACS/WFC subarray images of CAL-14410, taken taken with a large range of flash exposure times (0.1-30 seconds), to probe the temporal stability of the reference flash file and to validate the current post-flash correction pipeline of CALACS and ACS DESTRIPE PLUS on the new subarray modes. No statistically-significant deviations are found between the new post-flashed subarray exposures and the flash reference file, indicating that the LED lamp used to post-flash ACS images has been stable over several years. The current calibration pipelines (both CALACS and ACS DESTRIPE PLUS can be successfully used with the new subarray modes.

  12. Asymmetric ground reaction forces and knee kinematics during squat after anterior cruciate ligament (ACL) reconstruction.

    PubMed

    Sanford, Brooke A; Williams, John L; Zucker-Levin, Audrey; Mihalko, William M

    2016-10-01

    This bilateral squat study tests whether people with anterior cruciate ligament (ACL) reconstruction have symmetric three-dimensional ground reaction forces (GRFs) and symmetric anterior-posterior (AP) translation rates of the femur with respect to the tibia when compared with healthy control subjects. We hypothesized that there would be no long-term asymmetry in knee kinematics and kinetics in ACL reconstructed subjects following surgery and rehabilitation. Position and GRF data were collected on eight ACL reconstructed and eight control subjects during bilateral squat. The rate of relative AP translation was determined for each subject. Principal component models were developed for each of the three GRF waveforms. Principal component scores were used to assess symmetry within the ACL reconstructed group and within the control group. ACL reconstructed knees analyzed in early flexion during squat descent displayed a four-fold greater rate of change in anterior translation in the reconstructed knee relative to the contralateral side than did a similar comparison of normal knees. Differences were found between the ACL reconstructed subjects' injured and uninjured limbs for all GRFs. Subjects following ACL reconstruction had asymmetric GRFs and relative rates of AP translation at an average of seven years after ACL reconstructive surgery when compared with control subjects. These alterations in loading may lead to altered load distributions across the knee joint and may put some subjects at risk for future complications such as osteoarthritis. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Tissue-engineered collateral ligament composite allografts for scapholunate ligament reconstruction: an experimental study.

    PubMed

    Endress, Ryan; Woon, Colin Y L; Farnebo, Simon J; Behn, Anthony; Bronstein, Joel; Pham, Hung; Yan, Xinrui; Gambhir, Sanjiv S; Chang, James

    2012-08-01

    In patients with chronic scapholunate (SL) dissociation or dynamic instability, ligament repair is often not possible, and surgical reconstruction is indicated. The ideal graft ligament would recreate both anatomical and biomechanical properties of the dorsal scapholunate ligament (dorsal SLIL). The finger proximal interphalangeal joint (PIP joint) collateral ligament could possibly be a substitute ligament. We harvested human PIP joint collateral ligaments and SL ligaments from 15 cadaveric limbs. We recorded ligament length, width, and thickness, and measured the biomechanical properties (ultimate load, stiffness, and displacement to failure) of native dorsal SLIL, untreated collateral ligaments, decellularized collateral ligaments, and SL repairs with bone-collateral ligament-bone composite collateral ligament grafts. As proof of concept, we then reseeded decellularized bone-collateral ligament-bone composite grafts with green fluorescent protein-labeled adipo-derived mesenchymal stem cells and evaluated them histologically. There was no difference in ultimate load, stiffness, and displacement to failure among native dorsal SLIL, untreated and decellularized collateral ligaments, and SL repairs with tissue-engineered collateral ligament grafts. With pair-matched untreated and decellularized scaffolds, there was no difference in ultimate load or stiffness. However, decellularized ligaments revealed lower displacement to failure compared with untreated ligaments. There was no difference in displacement between decellularized ligaments and native dorsal SLIL. We successfully decellularized grafts with recently described techniques, and they could be similarly reseeded. Proximal interphalangeal joint collateral ligament-based bone-collateral ligament-bone composite allografts had biomechanical properties similar to those of native dorsal SLIL. Decellularization did not adversely affect material properties. These tissue-engineered grafts may offer surgeons another

  14. POEM: Identifying Joint Additive Effects on Regulatory Circuits

    PubMed Central

    Botzman, Maya; Nachshon, Aharon; Brodt, Avital; Gat-Viks, Irit

    2016-01-01

    Motivation: Expression Quantitative Trait Locus (eQTL) mapping tackles the problem of identifying variation in DNA sequence that have an effect on the transcriptional regulatory network. Major computational efforts are aimed at characterizing the joint effects of several eQTLs acting in concert to govern the expression of the same genes. Yet, progress toward a comprehensive prediction of such joint effects is limited. For example, existing eQTL methods commonly discover interacting loci affecting the expression levels of a module of co-regulated genes. Such “modularization” approaches, however, are focused on epistatic relations and thus have limited utility for the case of additive (non-epistatic) effects. Results: Here we present POEM (Pairwise effect On Expression Modules), a methodology for identifying pairwise eQTL effects on gene modules. POEM is specifically designed to achieve high performance in the case of additive joint effects. We applied POEM to transcription profiles measured in bone marrow-derived dendritic cells across a population of genotyped mice. Our study reveals widespread additive, trans-acting pairwise effects on gene modules, characterizes their organizational principles, and highlights high-order interconnections between modules within the immune signaling network. These analyses elucidate the central role of additive pairwise effect in regulatory circuits, and provide computational tools for future investigations into the interplay between eQTLs. Availability: The software described in this article is available at csgi.tau.ac.il/POEM/. PMID:27148351

  15. Flexible, polymer gated, AC-driven organic electroluminescence devices

    NASA Astrophysics Data System (ADS)

    Xu, Junwei; Carroll, David L.

    2017-08-01

    Comparing rigid inorganic layer, polymeric semiconducting gate layer exhibits superior flexibility as well as efficient carrier manipulation in high frequency AC cycles. Mechanism of the carrier manipulation at the gate in forward and reversed bias of AC cycle is studied. The flexible PET-based AC-OEL device with poly[(9,9-bis(3'-((N,N-dimethyl)-Nethylammonium)- propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN-Br) gate shows a stable electroluminescent performance in frequency sweep with a color rendering index (CRI) over 81 at 2800K color temperature.

  16. dc Arc Fault Effect on Hybrid ac/dc Microgrid

    NASA Astrophysics Data System (ADS)

    Fatima, Zahra

    The advent of distributed energy resources (DER) and reliability and stability problems of the conventional grid system has given rise to the wide spread deployment of microgrids. Microgrids provide many advantages by incorporating renewable energy sources and increasing the reliability of the grid by isolating from the main grid in case of an outage. AC microgrids have been installed all over the world, but dc microgrids have been gaining interest due to the advantages they provide over ac microgrids. However the entire power network backbone is still ac and dc microgrids require expensive converters to connect to the ac power network. As a result hybrid ac/dc microgrids are gaining more attention as it combines the advantages of both ac and dc microgrids such as direct integration of ac and dc systems with minimum number of conversions which increases the efficiency by reducing energy losses. Although dc electric systems offer many advantages such as no synchronization and no reactive power, successful implementation of dc systems requires appropriate protection strategies. One unique protection challenge brought by the dc systems is dc arc faults. A dc arc fault is generated when there is a gap in the conductor due to insulation degradation and current is used to bridge the gap, resulting in an arc with very high temperature. Such a fault if it goes undetected and is not extinguished can cause damage to the entire system and cause fires. The purpose of the research is to study the effect of the dc arc fault at different locations in the hybrid ac/dc microgrid and provide insight on the reliability of the grid components when it is impacted by arc faults at various locations in the grid. The impact of dc arc fault at different locations on the performance of the PV array, wind generation, and constant power loads (CPL) interfaced with dc/dc converters is studied. MATLAB/Simulink is used to model the hybrid ac/dc microgrid and arc fault.

  17. Using additive manufacturing in accuracy evaluation of reconstructions from computed tomography.

    PubMed

    Smith, Erin J; Anstey, Joseph A; Venne, Gabriel; Ellis, Randy E

    2013-05-01

    Bone models derived from patient imaging and fabricated using additive manufacturing technology have many potential uses including surgical planning, training, and research. This study evaluated the accuracy of bone surface reconstruction of two diarthrodial joints, the hip and shoulder, from computed tomography. Image segmentation of the tomographic series was used to develop a three-dimensional virtual model, which was fabricated using fused deposition modelling. Laser scanning was used to compare cadaver bones, printed models, and intermediate segmentations. The overall bone reconstruction process had a reproducibility of 0.3 ± 0.4 mm. Production of the model had an accuracy of 0.1 ± 0.1 mm, while the segmentation had an accuracy of 0.3 ± 0.4 mm, indicating that segmentation accuracy was the key factor in reconstruction. Generally, the shape of the articular surfaces was reproduced accurately, with poorer accuracy near the periphery of the articular surfaces, particularly in regions with periosteum covering and where osteophytes were apparent.

  18. Frequency-dependent tACS modulation of BOLD signal during rhythmic visual stimulation.

    PubMed

    Chai, Yuhui; Sheng, Jingwei; Bandettini, Peter A; Gao, Jia-Hong

    2018-05-01

    Transcranial alternating current stimulation (tACS) has emerged as a promising tool for modulating cortical oscillations. In previous electroencephalogram (EEG) studies, tACS has been found to modulate brain oscillatory activity in a frequency-specific manner. However, the spatial distribution and hemodynamic response for this modulation remains poorly understood. Functional magnetic resonance imaging (fMRI) has the advantage of measuring neuronal activity in regions not only below the tACS electrodes but also across the whole brain with high spatial resolution. Here, we measured fMRI signal while applying tACS to modulate rhythmic visual activity. During fMRI acquisition, tACS at different frequencies (4, 8, 16, and 32 Hz) was applied along with visual flicker stimulation at 8 and 16 Hz. We analyzed the blood-oxygen-level-dependent (BOLD) signal difference between tACS-ON vs tACS-OFF, and different frequency combinations (e.g., 4 Hz tACS, 8 Hz flicker vs 8 Hz tACS, 8 Hz flicker). We observed significant tACS modulation effects on BOLD responses when the tACS frequency matched the visual flicker frequency or the second harmonic frequency. The main effects were predominantly seen in regions that were activated by the visual task and targeted by the tACS current distribution. These findings bridge different scientific domains of tACS research and demonstrate that fMRI could localize the tACS effect on stimulus-induced brain rhythms, which could lead to a new approach for understanding the high-level cognitive process shaped by the ongoing oscillatory signal. © 2018 Wiley Periodicals, Inc.

  19. Apple MdACS6 Regulates Ethylene Biosynthesis During Fruit Development Involving Ethylene-Responsive Factor.

    PubMed

    Li, Tong; Tan, Dongmei; Liu, Zhi; Jiang, Zhongyu; Wei, Yun; Zhang, Lichao; Li, Xinyue; Yuan, Hui; Wang, Aide

    2015-10-01

    Ethylene biosynthesis in plants involves different 1-aminocyclopropane-1-carboxylic acid synthase (ACS) genes. The regulation of each ACS gene during fruit development is unclear. Here, we characterized another apple (Malus×domestica) ACS gene, MdACS6. The transcript of MdACS6 was observed not only in fruits but also in other tissues. During fruit development, MdACS6 was initiated at a much earlier stage, whereas MdACS3a and MdACS1 began to be expressed at 35 d before harvest and immediateley after harvest, respectively. Moreover, the enzyme activity of MdACS6 was significantly lower than that of MdACS3a and MdACS1, accounting for the low ethylene biosynthesis in young fruits. Overexpression of MdACS6 (MdACS6-OE) by transient assay in apple showed enhanced ethylene production, and MdACS3a was induced in MdACS6-OE fruits but not in control fruits. In MdACS6 apple fruits silenced by the virus-induced gene silencing (VIGS) system (MdACS6-AN), neither ethylene production nor MdACS3a transcript was detectable. In order to explore the mechanism through which MdACS3a was induced in MdACS6-OE fruits, we investigated the expression of apple ethylene-responsive factor (ERF) genes. The results showed that the expression of MdERF2 was induced in MdACS6-OE fruits and inhibited in MdACS6-AN fruits. Yeast one-hybrid assay showed that MdERF2 protein could bind to the promoter of MdACS3a. Moreover, down-regulation of MdERF2 in apple flesh callus led to a decrease of MdACS3a expression, demonstrating the regulation of MdERF2 on MdACS3a. The mechanism through which MdACS6 regulates the action of MdACS3a was discussed. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. Image transmission system using adaptive joint source and channel decoding

    NASA Astrophysics Data System (ADS)

    Liu, Weiliang; Daut, David G.

    2005-03-01

    In this paper, an adaptive joint source and channel decoding method is designed to accelerate the convergence of the iterative log-dimain sum-product decoding procedure of LDPC codes as well as to improve the reconstructed image quality. Error resilience modes are used in the JPEG2000 source codec, which makes it possible to provide useful source decoded information to the channel decoder. After each iteration, a tentative decoding is made and the channel decoded bits are then sent to the JPEG2000 decoder. Due to the error resilience modes, some bits are known to be either correct or in error. The positions of these bits are then fed back to the channel decoder. The log-likelihood ratios (LLR) of these bits are then modified by a weighting factor for the next iteration. By observing the statistics of the decoding procedure, the weighting factor is designed as a function of the channel condition. That is, for lower channel SNR, a larger factor is assigned, and vice versa. Results show that the proposed joint decoding methods can greatly reduce the number of iterations, and thereby reduce the decoding delay considerably. At the same time, this method always outperforms the non-source controlled decoding method up to 5dB in terms of PSNR for various reconstructed images.