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Sample records for orbital wall fracture

  1. Diplopia and orbital wall fractures.

    PubMed

    Boffano, Paolo; Roccia, Fabio; Gallesio, Cesare; Karagozoglu, K Hakki; Forouzanfar, Tymour

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and such fractures. This study is based on 2 databases that have continuously recorded data of patients hospitalized with maxillofacial fractures between 2001 and 2010. On the whole, 447 patients (334 males, 113 females) with pure blow-out orbital wall fractures were included. The most frequently involved orbital site was the floor (359 fractures), followed by medial wall (41 fractures) and lateral wall (5 fractures). At presentation, 227 patients (50.7%) had evidence of diplopia. In particular, in most patients, a diplopia in all directions was referred (78 patients). Statistically significant associations were found between diplopia on eye elevation and orbital floor fractures (P < 0.05) and between horizontal diplopia and medial wall fractures (P < 0.000005). In patients under evaluation for orbital trauma, the observation of diplopia on eye elevation and horizontal diplopia at presentation could be useful clinical indicators orbital floor and medial wall fractures, respectively.

  2. Late correction of orbital-zygomatic-maxillary fractures combined with orbital wall fractures.

    PubMed

    Lu, Wenjuan; Zhou, Huifang; Xiao, Caiwen; Shen, Qin; Lin, Ming; Fan, Xianqun

    2012-11-01

    With the increasing number of patients with facial trauma, orbital-zygomatic-maxillary (OZM) fracture combined with orbital wall fracture has become common. Such fractures always induce symptoms of enophthalmos, hypoglobus, and diplopia. This study was aimed to investigate the surgical technique and operative effect of late reconstruction of OZM fractures combined with orbital wall fractures. A retrospective analysis of the 46 patients (46 orbits) who were treated from January 2005 to December 2008 was performed. All cases had reconstruction of OZM fractures combined with orbital wall fractures at an average of 5.3 months after injury. Various incisions were selected. According to the computer-aided design/computer-aided manufacturing design, the osteotomy, reposition, and 4-point fixation of the fractured bones were individualized performed. Titanium mesh was preshaped according to the mirroring technology and inserted into the orbit with or without high-density polyethylene (HDPE) implant material to repair the orbital wall defect and the enlarged orbital volume. All patients were followed up 1 year after surgery. Forty-two of the 46 patients who had enophthalmos were completely corrected. Forty patients who had hypoglobus were corrected postoperatively. Of the 43 cases with diplopia, 20 cases were resolved. Late reconstruction by osteotomy and 4-point fixation could recover midface cosmesis, correct the enophthalmos, and improve the diplopia of OZM fractures combined with orbital wall fractures. The computer-aided design/computer-aided manufacturing system and mirroring technology can help improve the outcome of surgery when repairing such fractures.

  3. Reconstruction of Large Orbital Posterior Floor Wall Fracture Considering Orbital Floor Slope Using Endoscope.

    PubMed

    Park, Jinhwan; Huh, Jungah; Lee, Joonsik; Chang, Minwook; Lee, Hwa; Park, Minsoo; Baek, Sehyun

    2017-06-01

    Reconstruction of a large orbital fracture extending to the posterior wall of the maxillary sinus is difficult and challenging. In this study, the authors present transconjunctival or transcaruncular approach using endoscopy and layered porous polyethylene barrier sheets to manage large orbital floor wall fracture. A retrospective review of all patients who underwent reconstruction of large orbital floor wall fractures between June 2009 and July 2015 was conducted. Patient demographics, degree of enophthalmos, ocular motility and diplopia test results, and surgical complications were reviewed. This study included 53 eyes of 53 patients. The mean time from trauma to surgery was 34.1 days (range, 1-360 days). The average postoperative follow-up period was 6.1 months (range, 3-14 months). The degrees of enophthalmos preoperatively, and 1 week, 1 month, and 3 months postoperatively were -1.98 mm (range, -1.5 to -3 mm), 0.13 mm (range, -1.0 to +1.5 mm), -0.09 mm (range, -2.0 to +1.5 mm), and -0.43 mm (range, -2.0 to +1.0 mm), respectively. The mean improvement in enophthalmos at 3 months postoperation was 1.55 mm (P < 0.001). There was only 1 patient with residual 2 mm enophthalmos at 3 months postoperation. There were no definite surgical complications in any patient. Sufficient dissection to the posterior extent of the fracture and reconstruction of the orbital floor slope are the most important surgical factors to prevent residual enophthalmos. The authors believe using an endoscope and layered porous polyethylene are effective techniques in challenging patients with large orbital wall fracture.

  4. Considerations for the Management of Medial Orbital Wall Blowout Fracture

    PubMed Central

    Park, Youngsoo; Chung, Kyu Jin

    2016-01-01

    Recently, diagnoses of and operations for medial orbital blowout fracture have increased because of the development of imaging technology. In this article, the authors review the literature, and overview the accumulated knowledge about the orbital anatomy, fracture mechanisms, surgical approaches, reconstruction materials, and surgical methods. In terms of surgical approaches, transcaruncular, transcutaneous, and transnasal endoscopic approaches are discussed. Reconstruction methods including onlay covering, inlay implantation, and repositioning methods are also discussed. Consideration and understanding of these should lead to more optimal outcomes. PMID:27218019

  5. Transcaruncular Approach for Treatment of Medial Wall and Large Orbital Blowout Fractures

    PubMed Central

    Nguyen, Dennis C.; Shahzad, Farooq; Snyder-Warwick, Alison; Patel, Kamlesh B.; Woo, Albert S.

    2015-01-01

    We evaluate the safety and efficacy of the transcaruncular approach for reconstruction of medial orbital wall fractures and the combined transcaruncular–transconjunctival approach for reconstruction of large orbital defects involving the medial wall and floor. A retrospective review of the clinical and radiographic data of patients who underwent either a transcaruncular or a combined transcaruncular–transconjunctival approach by a single surgeon for orbital fractures between June 2007 and June 2013 was undertaken. Seven patients with isolated medial wall fractures underwent a transcaruncular approach, and nine patients with combined medial wall and floor fractures underwent a transcaruncular–transconjunctival approach with a lateral canthotomy. Reconstruction was performed using a porous polyethylene implant. All patients with isolated medial wall fractures presented with enophthalmos. In the combined medial wall and floor group, five out of eight patients had enophthalmos with two also demonstrating hypoglobus. The size of the medial wall defect on preoperative computed tomography (CT) scan ranged from 2.6 to 4.6 cm2; the defect size of combined medial wall and floor fractures was 4.5 to 12.7 cm2. Of the 11 patients in whom postoperative CT scans were obtained, all were noted to have acceptable placement of the implant. All patients had correction of enophthalmos and hypoglobus. One complication was noted, with a retrobulbar hematoma having developed 2 days postoperatively. The transcaruncular approach is a safe and effective method for reconstruction of medial orbital floor fractures. Even large fractures involving the orbital medial wall and floor can be adequately exposed and reconstructed with a combined transcaruncular–transconjunctival-lateral canthotomy approach. The level of evidence of this study is IV (case series with pre/posttest). PMID:26889348

  6. 'Orbital volume restoration rate after orbital fracture'; a CT-based orbital volume measurement for evaluation of orbital wall reconstructive effect.

    PubMed

    Wi, J M; Sung, K H; Chi, M

    2017-01-13

    PurposeTo evaluate the effect of orbital reconstruction and factors related to the effect of orbital reconstruction by assessing of orbital volume using orbital computed tomography (CT) in cases of orbital wall fracture.MethodsIn this retrospective study, 68 patients with isolated blowout fractures were evaluated. The volumes of orbits and herniated orbital tissues were determined by CT scans using a three-dimensional reconstruction technique (the Eclipse Treatment Planning System). Orbital CT was performed preoperatively, immediately after surgery, and at final follow ups (minimum of 6 months). We evaluated the reconstructive effect of surgery making a new formula, 'orbital volume reconstruction rate' from orbital volume differences between fractured and contralateral orbits before surgery, immediately after surgery, and at final follow up.ResultsMean volume of fractured orbits before surgery was 23.01±2.60 cm(3) and that of contralateral orbits was 21.31±2.50 cm(3) (P=0.005). Mean volume of the fractured orbits immediately after surgery was 21.29±2.42 cm(3), and that of the contralateral orbits was 21.33±2.52 cm(3) (P=0.921). Mean volume of fractured orbits at final follow up was 21.50±2.44 cm(3), and that of contralateral orbits was 21.32±2.50 cm(3) (P=0.668). The mean orbital volume reconstruction rate was 100.47% immediately after surgery and 99.17% at final follow up. No significant difference in orbital volume reconstruction rate was observed with respect to fracture site or orbital implant type. Patients that underwent operation within 14 days of trauma had a better reconstruction rate at final follow up than patients who underwent operation over 14 days after trauma (P=0.039).ConclusionComputer-based measurements of orbital fracture volume can be used to evaluate the reconstructive effect of orbital implants and provide useful quantitative information. Significant reduction of orbital volume is observed immediately after orbital wall

  7. Isolated lesion of the medial orbital wall following endonasal surgery. Isolated fractures of the medial orbital wall.

    PubMed

    Scassellati-Sforzolini, G; Cavina, C; Scassellati-Sforzolini, B; Vancini, F; Cavina, C

    Isolated fractures of the medial orbital wall are infrequent. The diagnostic triad includes: adduction block, exotropia with diplopia in all directions of gaze, positive passive duction in abduction. Sometimes a slight enophthalmos is present. Computed tomography shows the extension and the seat of the fracture. The authors illustrate the case of a 60 year old male who presented with a breach of the medial orbital wall following endonasal surgery. The patient was successfully operated using an iliac bone graft inserted via an eyebrow-nasal cutaneous approach, after a previous attempt with a transconjunctival approach performed in another hospital had failed. A good functional and aesthetic result was observed within the first year after surgery. After almost 11 years a full adduction is still present and diplopia is absent. The authors underline the importance of an early diagnosis and prompt surgical treatment. The fat-muscle entrapment should be removed and the bone defect closed. A close cooperation between ophthalmologist and plastic surgeon is suggested.

  8. Combination of absorbable mesh and demineralized bone matrix in orbital wall fracture for preventing herniation of orbit.

    PubMed

    Tak, Kyoung Seok; Jung, Min Su; Lee, Byeong Ho; Kim, Joo Hyun; Ahn, Duk Kyun; Jeong, Hii Sun; Park, Young Kyu; Suh, In Suck

    2014-07-01

    After restoration of orbit wall fracture, preventing sequelae is important. An absorbable mesh is commonly used in orbit wall fracture, yet it has limitation due to orbit sagging when bony defect is larger than the moderate size (1 × 1 cm2). In this study, the authors present a satisfactory result in treating orbit wall fracture larger than the moderate size with a combination of absorbable mesh and demineralized bone matrix.From 2009 to 2012, 63 patients with bony defect larger than the moderate size, who were treated with a combination of absorbable mesh and demineralized bone matrix, were reviewed retrospectively. The site of bony defect, size, and applied amount of demineralized bone matrix were reviewed, and a 2-year follow-up was done. Facial computed tomography scans were checked preoperative, immediate postoperative, and 2-year postoperative.Among the 63 patients, there were 52 men and 11 women. Mean age was 33.3 years. The most common cause was blunt blow (35 cases); mean defect size was 13.36 × 12.82 mm2 in inferior wall fracture and 20.69 × 14.41 mm2 in medial wall fracture. There was no complication except for 3 cases of infraorbital nerve hypoesthesia. A 2-year follow-up computed tomography showed that the surgical site preserved bony formation without herniation. In treating moderate-sized bony defect in orbit wall fracture, absorbable mesh and demineralized bone matrix can maintain structural stability through good bony formation even after degradation of absorbable mesh.

  9. [Systemic enzyme therapy in the treatment of children with lower orbital wall fractures].

    PubMed

    Dubovskaia, L A; Guseva, M R; Gorbunova, E D; Gorbunov, A V; Kazinskaia, N V

    2006-01-01

    Wobenzim, a drug for systemic enzyme therapy, was used in 26 children with lower orbital wall fractures as monotherapy in early periods (on days 1 to 7) after brain injury to improve healing conditions and to minimize the formation of scar tissues in the fractural area. A control group comprised 24 patients who received systemic dehydration and vessel-strengthening therapy. Systemic enzyme therapy with Wobenzim could reduce the attenuation time of inflammatory manifestations of injury, prevent complications, such as strangulation of the musculus rectus inferior in the fractural area and development of strangulated orbital soft tissue hernia, and substantially decrease the number of patients having indications for surgical plastic repair of the orbital wall, as compared with the control group.

  10. Correlation between the 2-Dimensional Extent of Orbital Defects and the 3-Dimensional Volume of Herniated Orbital Content in Patients with Isolated Orbital Wall Fractures

    PubMed Central

    Cha, Jong Hyun; Moon, Myeong Ho; Lee, Yong Hae; Koh, In Chang; Kim, Kyu Nam; Kim, Chang Gyun

    2017-01-01

    Background The purpose of this study was to assess the correlation between the 2-dimensional (2D) extent of orbital defects and the 3-dimensional (3D) volume of herniated orbital content in patients with an orbital wall fracture. Methods This retrospective study was based on the medical records and radiologic data of 60 patients from January 2014 to June 2016 for a unilateral isolated orbital wall fracture. They were classified into 2 groups depending on whether the fracture involved the inferior wall (group I, n=30) or the medial wall (group M, n=30). The 2D area of the orbital defect was calculated using the conventional formula. The 2D extent of the orbital defect and the 3D volume of herniated orbital content were measured with 3D image processing software. Statistical analysis was performed to evaluate the correlations between the 2D and 3D parameters. Results Varying degrees of positive correlation were found between the 2D extent of the orbital defects and the 3D herniated orbital volume in both groups (Pearson correlation coefficient, 0.568−0.788; R2=32.2%−62.1%). Conclusions Both the calculated and measured 2D extent of the orbital defects showed a positive correlation with the 3D herniated orbital volume in orbital wall fractures. However, a relatively large volume of herniation (>0.9 cm3) occurred not infrequently despite the presence of a small orbital defect (<1.9 cm2). Therefore, estimating the 3D volume of the herniated content in addition to the 2D orbital defect would be helpful for determining whether surgery is indicated and ensuring adequate surgical outcomes. PMID:28194344

  11. Repair of the Orbital Wall Fractures in Rabbit Animal Model Using Nanostructured Hydroxyapatite-Based Implant

    PubMed Central

    Gradinaru, Sinziana; Popescu, Laura Madalina; Piticescu, Roxana Mioara; Zurac, Sabina; Ciuluvica, Radu; Burlacu, Alexandrina; Tutuianu, Raluca; Valsan, Sorina-Nicoleta; Motoc, Adrian Mihail; Voinea, Liliana Mary

    2016-01-01

    Cellular uptake and cytotoxicity of nanostructured hydroxyapatite (nanoHAp) are dependent on its physical parameters. Therefore, an understanding of both surface chemistry and morphology of nanoHAp is needed in order to be able to anticipate its in vivo behavior. The aim of this paper is to characterize an engineered nanoHAp in terms of physico-chemical properties, biocompatibility, and its capability to reconstitute the orbital wall fractures in rabbits. NanoHAp was synthesized using a high pressure hydrothermal method and characterized by physico-chemical, structural, morphological, and optical techniques. X-ray diffraction revealed HAp crystallites of 21 nm, while Scanning Electron Microscopy (SEM) images showed spherical shapes of HAp powder. Mean particle size of HAp measured by DLS technique was 146.3 nm. Biocompatibility was estimated by the effect of HAp powder on the adhesion and proliferation of mesenchymal stem cells (MSC) in culture. The results showed that cell proliferation on powder-coated slides was between 73.4% and 98.3% of control cells (cells grown in normal culture conditions). Computed tomography analysis of the preformed nanoHAp implanted in orbital wall fractures, performed at one and two months postoperative, demonstrated the integration of the implants in the bones. In conclusion, our engineered nanoHAp is stable, biocompatible, and may be safely considered for reconstruction of orbital wall fractures. PMID:28344268

  12. Medpor Implant Fixation Using Fibrin Glue in the Treatment of Medial Orbital Wall Fracture.

    PubMed

    Kang, Nakheon; Song, Seung Han; Kyung, Hyunwoo; Oh, Sang-Ha

    2015-06-01

    The optimal treatment modalities are determined based on the symptoms and degree of the bone defects in patients with medial orbital wall blowout fracture. Most of the patients in this series underwent implant surgery. However, there are many patients whose implants were not fixed during surgery. Therefore, some patients who had implant migration occurred had been reported. We have therefore used methods for applying fibrin glue (Tisseel, Baxter Healthcare, Norfolk, United Kingdom) for the fixation of implant. Between 2007 and 2013, a total of 168 patients underwent porous polyethylene orbital implant (Medpor) surgery with the application of Tisseel. All the patients underwent surgical treatments via a transcaruncular approach, for which the Medpor was used. Postoperative complications include 6 cases of the limitation of extraoccular movement, 10 cases of diplopia, and 7 cases of enophthalmos. However, there were no specific complications caused by Tisseel. All the patients were satisfied with the treatment outcomes. In this study, we report the usefulness of Tisseel in the fixation of the medial orbital wall fracture using the Medpor implant with a review of literatures.

  13. Patient specific implants (PSI) in reconstruction of orbital floor and wall fractures.

    PubMed

    Gander, Thomas; Essig, Harald; Metzler, Philipp; Lindhorst, Daniel; Dubois, Leander; Rücker, Martin; Schumann, Paul

    2015-01-01

    Fractures of the orbital wall and floor can be challenging due to the demanding three-dimensional anatomy and limited intraoperative overview. Misfitting implants and inaccurate surgical technique may lead to visual disturbance and unaesthetic results. A new approach using individually manufactured titanium implants (KLS Martin, Group, Germany) for daily routine is presented in the current paper. Preoperative CT-scan data were processed in iPlan 3.0.5 (Brainlab, Feldkirchen, Germany) to generate a 3D-reconstruction of the affected orbit using the mirrored non-affected orbit as template and the extent of the patient specific implant (PSI) was outlined and three landmarks were positioned on the planned implant in order to allow easy control of the implant's position by intraoperative navigation. Superimposition allows the comparison of the postoperative result with the preoperative planning. Neither reoperation was indicated due to malposition of the implant and the ocular bulb nor visual impairments could be assessed. PSI allows precise reconstruction of orbital fractures by using a complete digital workflow and should be considered superior to manually bent titanium mesh implants.

  14. Prospective study on ocular motility limitation due to orbital muscle entrapment or impingement associated with orbital wall fracture.

    PubMed

    Alinasab, Babak; Qureshi, Abdul Rashid; Stjärne, Pär

    2017-07-01

    The recommended urgent surgical management of ocular motility restriction due to orbital muscle entrapment or impingement associated with orbital wall fracture needs to be elucidated. To evaluate the importance of the time from injury to surgery for the outcome in ocular motility and diplopia, the time lapse of ocular motility, diplopia and hypesthesia recovery. Patients with entrapment or impingement of orbital contents due to orbital wall fracture were followed up prospectively over 1year regarding ocular motility, diplopia, hypesthesia and cosmetic deformity. 21 patients (10 entrapments and 11 impingements) were included and treated surgically. The median time from injury to surgery was 36 (8-413)h for the entrapment group and 168 (48-326)h for the impingement group. The median time from study inclusion to surgery was 0 (0-1) days for the entrapment group and 1.0 (0.2-4.8) days for the impingement group. All the patients had ocular motility limitation and diplopia at the inclusion. Ocular motility improved gradually and was normal at final visit. Diplopia resolved gradually in all patients except in two with non-disturbing diplopia, at the final visit. Forced duction test was positive in 90% of the patients in the entrapment group and 70% in impingement group. At final visit, hypesthesia was found in none of the patients in the entrapment group but in 4 patients in the impingement group. In this, the first prospective long term follow up of orbital wall fractures with ocular motility restriction, we did not find any significant correlation between the time from injury to surgery and the outcomes in ocular motility and diplopia. An entrapment requires surgery as soon as possible; however, the surgical reduction is at least as important as surgical timing. Surgery should be delayed until it can be performed by an experienced surgeon. Ocular motility restriction causing diplopia due to impingement is not an ophthalmologic emergency and surgery is recommended if the

  15. Reconstruction of Orbital Floor Fractures with Autogenous Bone Graft Application from Anterior Wall of Maxillary Sinus: A Retrospective Study.

    PubMed

    Bande, Chandrashekhar R; Daware, Surendra; Lambade, Pravin; Patle, Bhaskar

    2015-09-01

    Orbital wall fracture implies a situation where disruptions of the walls or floor have occurred. It is a blowout type fracture where bone fragments with torn periosteum are pushed outside of the original bony orbit. There is no intact bone even near the defect area except the thin bone rim surrounding the blowout fracture. The purpose of this defect repair is to support orbital contents, free entrapped tissue, and, especially, restore the original orbital volume. Ten patients (seven males and three females) who underwent repair of orbital floor factures with maxillary sinus bone grafts were included in this study. Surgical procedure for harvesting graft and its fixation was almost same in all operated cases. The collection in the maxillary sinus due to fracture of floor of orbit, blood and bony fragments collected in the maxillary sinus can be easily drained and removed after removal of anterior wall of maxillary sinus and through the same approach you can reduce the floor of orbit manually to the proper position which helps to decease the orbital floor defect.

  16. Treatment of Orbital Medial Wall Fractures with Titanium Mesh Plates Using Retrocaruncular Approach: Outcomes with Different Techniques

    PubMed Central

    Gerbino, Giovanni; Zavattero, Emanuele; Viterbo, Stefano; Ramieri, Guglielmo

    2015-01-01

    Surgical management of medial wall orbital fractures should be considered to avoid diplopia and posttraumatic enophthalmos. Treatment of these fractures remains a challenge for the maxillofacial surgeon because of complex anatomy and limited vision. This article aims to retrospectively evaluate the outcomes in the repair of medial orbital wall fractures using a retrocaruncular approach and titanium meshes, comparing the placement of the titanium mesh with three different techniques: (1) conventional free hand under direct vision, (2) with the assistance of an endoscope, and (c) with the assistance of a navigation system. Eighteen patients who underwent surgery for orbital medial wall fracture were enrolled in the study. On the basis of the implant placement technique, three groups were identified: group 1 (CONV), conventional free hand under direct vision; group 2 (ENDO), endoscopically assisted; group 3 (NAVI), a navigational system assisted (BrainLab, Feldkirchen, Germany). The postoperative quality of orbital reconstruction was assessed as satisfactory in 12 cases, good in 4 cases, and unsatisfactory in 2 cases. Particularly in group 1 (CONV) in four patients out of eight, the posterior ledge of the fracture was not reached by the implant and in one patient the mesh hinged toward the ethmoid. In group 3 (NAVI), in one patient out of five, the posterior ledge of the fracture was not reached. In conclusion, titanium orbital mesh plates and retrocaruncular approach are a reliable method to obtain an accurate orbital medial wall reconstruction. The use of endoscopic assistance through the surgical incisions improves accuracy of treatment allowing better visualization of the surgical field. Navigation aided surgery is a feasible technique especially for complex orbital reconstruction to improve predictability and outcomes in orbital repair. PMID:26576238

  17. Application of Rapid Prototyping Technique and Intraoperative Navigation System for the Repair and Reconstruction of Orbital Wall Fractures

    PubMed Central

    Cha, Jong Hyun; Lee, Yong Hae; Ruy, Wan Chul; Roe, Young; Moon, Myung Ho

    2016-01-01

    Background Restoring the orbital cavity in large blow out fractures is a challenge for surgeons due to the anatomical complexity. This study evaluated the clinical outcomes and orbital volume after orbital wall fracture repair using a rapid prototyping (RP) technique and intraoperative navigation system. Methods This prospective study was conducted on the medical records and radiology records of 12 patients who had undergone a unilateral blow out fracture reconstruction using a RP technique and an intraoperative navigation system from November 2014 to March 2015. The surgical results were assessed by an ophthalmic examination and a comparison of the preoperative and postoperative orbital volume ratio (OVR) values. Results All patients had a successful treatment outcome without complications. Volumetric analysis revealed a significant decrease in the mean OVR from 1.0952±0.0662 (ranging from 0.9917 to 1.2509) preoperatively to 0.9942±0.0427 (ranging from 0.9394 to 1.0680) postoperatively. Conclusion The application of a RP technique for the repair of orbital wall fractures is a useful tool that may help improve the clinical outcomes by understanding the individual anatomy, determining the operability, and restoring the orbital cavity volume through optimal implant positioning along with an intraoperative navigation system. PMID:28913272

  18. Application of Rapid Prototyping Technique and Intraoperative Navigation System for the Repair and Reconstruction of Orbital Wall Fractures.

    PubMed

    Cha, Jong Hyun; Lee, Yong Hae; Ruy, Wan Chul; Roe, Young; Moon, Myung Ho; Jung, Sung Gyun

    2016-09-01

    Restoring the orbital cavity in large blow out fractures is a challenge for surgeons due to the anatomical complexity. This study evaluated the clinical outcomes and orbital volume after orbital wall fracture repair using a rapid prototyping (RP) technique and intraoperative navigation system. This prospective study was conducted on the medical records and radiology records of 12 patients who had undergone a unilateral blow out fracture reconstruction using a RP technique and an intraoperative navigation system from November 2014 to March 2015. The surgical results were assessed by an ophthalmic examination and a comparison of the preoperative and postoperative orbital volume ratio (OVR) values. All patients had a successful treatment outcome without complications. Volumetric analysis revealed a significant decrease in the mean OVR from 1.0952±0.0662 (ranging from 0.9917 to 1.2509) preoperatively to 0.9942±0.0427 (ranging from 0.9394 to 1.0680) postoperatively. The application of a RP technique for the repair of orbital wall fractures is a useful tool that may help improve the clinical outcomes by understanding the individual anatomy, determining the operability, and restoring the orbital cavity volume through optimal implant positioning along with an intraoperative navigation system.

  19. Using the Endoscopic Transconjunctival and Transcaruncular Approach to Repair Combined Orbital Floor and Medial Wall Blowout Fractures.

    PubMed

    Chang, Minwook; Yang, Seong Won; Park, Jin-Hwan; Lee, Joonsik; Lee, Hwa; Park, Min Soo; Baek, Sehyun

    2017-06-01

    To demonstrate the effectiveness of the endoscopic transcaruncular and transconjunctival approach in the repair of combined medial and inferior orbital wall fractures. A retrospective chart review was conducted on 160 patients with combined medial and inferior orbital wall fractures. All patients underwent surgery via an endoscopic transcaruncular and transconjunctival approach without lateral canthotomy, performed by a single surgeon. Porous polyethylene sheets (1.0 mm in thickness) were implanted to cover the orbital defects. The minimal postoperative follow-up period was 6 months. The authors evaluated enophthalmos, diplopia, and ocular motility pre and postoperatively and report surgical complications. A total of 160 patients were included, comprising 121 men and 39 women. The mean patient age was 33.9 ± 14.1 years, and the mean postoperative follow-up period was 12 months. The average enophthalmos was 3.20 mm preoperatively, and the mean improvement at 6 months after surgery was 2.82 mm. One patient suffered a canalicular laceration after surgery, and another retrobulbar hemorrhage; however, both of these complications resolved with appropriate management. Otherwise, there were no significant surgical complications including newly developed diplopia, decreased visual acuity, or cerebrospinal fluid leakage. The endoscopic transcaruncular and transconjunctival approach is a useful and promising technique to repair combined medial and inferior orbital wall fractures.

  20. Orbital fractures: a review

    PubMed Central

    Joseph, Jeffrey M; Glavas, Ioannis P

    2011-01-01

    This review of orbital fractures has three goals: 1) to understand the clinically relevant orbital anatomy with regard to periorbital trauma and orbital fractures, 2) to explain how to assess and examine a patient after periorbital trauma, and 3) to understand the medical and surgical management of orbital fractures. The article aims to summarize the evaluation and management of commonly encountered orbital fractures from the ophthalmologic perspective and to provide an overview for all practicing ophthalmologists and ophthalmologists in training. PMID:21339801

  1. Template-Based Orbital Wall Fracture Treatment Using Statistical Shape Analysis.

    PubMed

    Doerfler, Hans-Martin; Huempfner-Hierl, Heike; Kruber, Daniel; Schulze, Peter; Hierl, Thomas

    2017-07-01

    Aim of this study was to investigate whether a mold generated from a statistical shape model of the orbit could be generated to provide a cost-efficient means for the treatment of orbital fractures. A statistical shape model was created from 131 computed tomographic (CT) scans of unaffected adult middle European human orbits. To generate the model, CT scans were segmented in Brainlab software, preregistered using anatomic landmarks, trimmed to an identical size, and definitely registered. Then, the model was created using the global master algorithm. Based on this model, a mold consisting of a male part and a female part was constructed and printed using a rapid prototyping technique. A statistical shape model of the human orbit was generated from 125 CT scans. Six scans (4.5%) presented major anatomic deviations and were discarded. A solid mold based on this model was printed. Using this mold, flat titanium mesh could be successfully deformed to serve as an orbital implant. A mold based on the statistical orbital shape could serve as a cost-effective means for the treatment of orbital fractures. It allows the anatomic preformation of titanium or resorbable implant material for orbital reconstruction. Because these materials could be cut from larger sheets, the use of a mold would be a cost-effective treatment alternative. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  2. A peculiar blow-out fracture of the inferior orbital wall complicated by extensive subcutaneous emphysema: A case report and review of the literature.

    PubMed

    Rzymska-Grala, Iwona; Palczewski, Piotr; Błaż, Marcin; Zmorzyński, Michał; Gołębiowski, Marek; Wanyura, Hubert

    2012-04-01

    Blow-out fracture of the orbit is a common injury. However, not many cases are associated with massive subcutaneous emphysema. Even fewer cases are caused by minor trauma or are associated with barotrauma to the orbit due to sneezing, coughing, or vomiting. The authors present a case of blow-out fracture complicated by extensive subcutaneous and mediastinal emphysema that occurred without any obvious traumatic event. A 43-year-old man presented to the Emergency Department with a painful right-sided exophthalmos that he had noticed in the morning immediately after waking up. The patient also complained of diplopia. Physical examination revealed exophthalmos and crepitations suggestive of subcutaneous emphysema. The eye movements, especially upward gaze, were impaired. CT showed blow-out fracture of the inferior orbital wall with a herniation of the orbital soft tissues into the maxillary sinus. There was an extensive subcutaneous emphysema in the head and neck going down to the mediastinum. The patient did not remember any significant trauma to the head that could explain the above mentioned findings. At surgery, an inferior orbital wall fracture with a bony defect of 3×2 centimeter was found and repaired. Blow-out fractures of the orbit are usually a result of a direct trauma caused by an object with a diameter exceeding the bony margins of the orbit. In 50% of cases, they are complicated by orbital emphysema and in 4% of cases by herniation of orbital soft tissues into paranasal sinuses. The occurrence of orbital emphysema without trauma is unusual. In some cases it seems to be related to barotrauma due to a rapid increase in pressure in the upper airways during sneezing, coughing, or vomiting, which very rarely leads to orbital wall fracture. Computed tomography is the most accurate method in detecting and assessing the extent of orbital wall fractures.

  3. Reconstruction of a Complicated Orbital Depression Fracture with Medial Wall and Globe Repositioning in a Horse: A Collaboration Across Disciplines and Specialties.

    PubMed

    McMaster, Mattie; Caldwell, Fred; Gillen, Alexandra; Hespel, Adrien; Budny, Patrick; Abarca, Eva

    2016-05-01

    To report the surgical reconstruction of a complicated orbital depression fracture in a horse with emphasis on medial wall and globe repositioning. Clinical report. A 6 year old Irish Sport Horse gelding. The eventer presented with acute, severe orbital trauma and globe displacement. After initial elevation of the depression fractures of the facial bones and reconstruction of the orbit, the globe was recessed secondary to displacement of the medial wall and floor of the orbit within the conchofrontal sinus. A three-dimensional model of the fracture configuration was used for presurgical planning to reposition the globe. During a subsequent surgical procedure, a resorbable plate was placed in the floor of the orbit and the medial orbital wall and globe were repositioned using a sinoscopic approach and stabilized with the placement of tissue expanders within the conchofrontal sinus. The tissue expanders were subsequently removed after 3 weeks under standing sedation. The right globe was successfully repositioned in a more correct anatomical orientation and the horse resumed work 3 months postoperatively, and successfully competed at its previous level 5 months postoperatively. No visual deficits have been reported by the owners. Efforts to restore the medial wall and/or floor of the orbit with concurrent globe repositioning should be considered in horses with severe orbital depression fractures that result in abnormal globe position. © Copyright 2016 by The American College of Veterinary Surgeons.

  4. Two-Year Follow-up on the Use of Absorbable Mesh Plates in the Treatment of Medial Orbital Wall Fractures

    PubMed Central

    You, Jae-Pil; Kim, Deok-Woo; Jeon, Byung-Joon; Jeong, Seong-Ho; Han, Seung-Kyu; Kim, Woo-Kyung

    2013-01-01

    Background Absorbable materials offer many advantages in the reconstruction of orbital walls; however, the possibility of postoperative enophthalmos after complete absorption cannot be excluded. We evaluated the postoperative results of absorbable mesh plates used as onlay implanting on the medial orbital wall to determine whether they are suitable for medial orbital wall reconstruction. Methods The study included 20 patients with medial orbital wall fractures who were followed up for more than 2 years postoperatively. We used absorbable mesh plates in all of the patients. We measured the following: the changes in the expanded orbital volume by comparing the preoperative and postoperative computed tomography (CT) scans and the degree of clinical enophthalmos. Results There were no major complications associated with the use of absorbable materials such as infection, migration, or extrusion of mesh plates during the long-term follow-up. The orbital volumetric changes between the preoperative and postoperative CT scans were not statistically significant. However, the expanded orbital volume was not related to the degree of clinical enophthalmos. Conclusions The reconstructed orbital wall may provide supportive scar tissue to the orbital contents even after the absorbable materials have dissolved completely. Absorbable mesh plates could be another option for the reconstruction of the medial orbital wall. PMID:24286046

  5. Pediatric Orbital Fractures

    PubMed Central

    Oppenheimer, Adam J.; Monson, Laura A.; Buchman, Steven R.

    2013-01-01

    It is wise to recall the dictum “children are not small adults” when managing pediatric orbital fractures. In a child, the craniofacial skeleton undergoes significant changes in size, shape, and proportion as it grows into maturity. Accordingly, the craniomaxillofacial surgeon must select an appropriate treatment strategy that considers both the nature of the injury and the child's stage of growth. The following review will discuss the management of pediatric orbital fractures, with an emphasis on clinically oriented anatomy and development. PMID:24436730

  6. Clinical features and treatment of pediatric orbit fractures.

    PubMed

    Hink, Eric M; Wei, Leslie A; Durairaj, Vikram D

    2014-01-01

    To describe a series of orbital fractures and associated ophthalmic and craniofacial injuries in the pediatric population. A retrospective case series of 312 pediatric patients over a 9-year period (2002-2011) with orbit fractures diagnosed by CT. Five hundred ninety-one fractures in 312 patients were evaluated. There were 192 boys (62%) and 120 girls (38%) with an average age of 7.3 years (range 4 months to 16 years). Orbit fractures associated with other craniofacial fractures were more common (62%) than isolated orbit fractures (internal fractures and fractures involving the orbital rim but without extension beyond the orbit) (38%). Roof and medial wall fractures were most common (30% and 28%, respectively), followed by orbital floor (24%) and lateral wall (18%) fractures. Orbital roof fractures are the most common fracture in patients <8 years old, whereas orbital floor fractures are the most common fracture in patients older than 8 years. Eighty-seven patients (28%) underwent surgical repair. There is an increasing incidence of surgery in older patients (p = 0.02). Associated neurologic injuries were more common (23%) than associated ophthalmic injuries (20%). Pediatric orbit fracture patterns are dictated by the age of the patient with respect to their craniofacial morphology and mechanism of injury. Orbital roof fractures are more likely to occur in younger patients and not require surgery, whereas orbital floor fractures are more common in older patients and are more likely to require surgery.

  7. Biomaterials for orbital fractures repair

    PubMed Central

    Totir, M; Ciuluvica, R; Dinu, I; Careba, I; Gradinaru, S

    2015-01-01

    The unique and complex anatomy of the orbit requires significant contouring of the implants to restore the proper anatomy. Fractures of the orbital region have an incidence of 10-25% from the total facial fractures and the most common age group was the third decade of life. The majority of cases required reconstruction of the orbital floor to support the globe position and restore the shape of the orbit. The reason for this was that the bony walls were comminuted and/ or bone fragments were missing. Therefore, the reconstruction of the missing bone was important rather than reducing the bone fragments. This could be accomplished by using various materials. There is hardly any anatomic region in the human body that is so controversial in terms of appropriate material used for fracture repair: non resorbable versus resorbable, autogenous/ allogeneic/ xenogenous versus alloplastic material, non-prebent versus preformed (anatomical) plates, standard versus custom-made plates, nonporous versus porous material, non-coated versus coated plates. Thus, the importance of the material used for reconstruction becomes more challenging for the ophthalmologist and the oral and maxillofacial surgeon. PMID:25914737

  8. Role of Negative Vector Orbit in Orbital Blow-Out Fractures.

    PubMed

    Choi, Soo Youn; Lee, Hwa; Baek, Sehyun

    2017-09-12

    Negative vector orbit is defined as the most anterior globe portion protrudes past the malar eminence. The aim of the study was to evaluate the relationship between negative vector orbit and blow-out fracture location analyzing the distance between the anterior corneal surface and orbital bone with facial soft tissue in medial and orbital floor blow out fractures using orbital computed tomography (CT). Seventy-seven patients diagnosed with blow-out fractures involving the medial or orbital floor were included. Distances from the anterior cornea to lower lid fat, inferior orbital wall, inferior orbital rim, and anterior cheek mass were measured using orbital CT scans. The proportion of negative vector orbit and measured distanced were compared between medial wall fracture and orbital floor fracture. Medical records including age, sex, concomitant ophthalmic diagnosis, and nature of injury were retrospectively reviewed. Forty-three eyes from 43 patients diagnosed with medial wall fracture and 34 eyes from 34 patients diagnosed with orbital floor fracture were included. There was no significant difference in the distance from the anterior cornea to lower lid fat (P = 0.574), inferior orbital wall (P = 0.494), or orbital rim (P = 0.685). The distance from anterior cornea to anterior cheek mass was significantly different in medial wall fracture (-0.19 ± 3.49 mm) compared with orbital floor fracture (-1.69 ± 3.70 mm), P = 0.05. Negative vector orbit was significantly higher in orbital floor fracture patients (24 among 34 patients, 70.6%) compared with those with medial wall fractures (19 among 43 patients, 44.2%) (P = 0.04). Patients presenting with a negative vector orbit relationship when the most anterior portion of globe protruded past the anterior cheek mass and malar eminence were more likely to develop orbital floor fracture than medial wall fracture.

  9. Patterns and injuries associated with orbital wall fractures in elderly patients who visited the emergency room: a retrospective case–control study

    PubMed Central

    Kim, Youn-Jung; Ahn, Shin; Seo, Dong-Woo; Sohn, Chang Hwan; Lee, Hyung-Joo; Park, In-June; Yang, Dong-Jin; Ryoo, Seung Mok; Kim, Won Young; Lim, Kyung Soo

    2016-01-01

    Objectives This study aimed to determine orbital wall fracture (OWF) patterns and associated facial injuries in elderly patients and compare them with those in their younger adult counterparts. Design A retrospective case–control study. Setting An emergency department of a university-affiliated hospital located in an urban area. Participants A total of 1378 adult patients with OWF diagnosed by CT from 1 January 2004 through 31 March 2014 were enrolled. Patients were categorised into elderly (≥65 years) and non-elderly (<65 years) groups. Results The elderly group (n=146) had a mean age of 74.0 years compared with 37.5 years in the non-elderly group (n=1232). Slipping was the most common cause of OWF in the elderly group (43.8%, p<0.001), whereas violence was the most common cause in the non-elderly group (37.3%, p<0.001). The lateral orbital wall was the more common site of fracture in the elderly group, and their injuries were more often associated with concurrent facial bone fractures, including the mandible, maxilla and zygoma, compared with the non-elderly group. After adjusting for sex and the mechanism of injury, inclusion in the elderly group was a significant risk factor for fracture of the lateral wall (OR 1.658; 95% CI 1.074 to 2.560) and concomitant facial bone fractures of the maxilla (OR 1.625; 95% CI 1.111 to 2.377) and zygoma (OR 1.670; 95% CI 1.126 to 2.475). Conclusions Elderly patients were vulnerable to facial trauma, and concurrent facial bone fracture associated with OWF was more commonly observed in this age group. Therefore, a high index of suspicion and thorough investigation, including CT, for OWF-associated facial bone fractures are important. PMID:27645553

  10. Antibiotic Prophylaxis in Orbital Fractures

    PubMed Central

    Reiss, Benjamin; Rajjoub, Lamise; Mansour, Tamer; Chen, Tony; Mumtaz, Aisha

    2017-01-01

    Purpose: To determine whether prophylactic antibiotic use in patients with orbital fracture prevent orbital infection. Design: Retrospective cohort study. Participants: All patients diagnosed with orbital fracture between January 1, 2008 and March 1, 2014 at The George Washington University Hospital and Clinics. Main Outcome Measures: Development of orbital infection. Results: One hundred seventy-two patients with orbital fracture met our inclusion and exclusion criteria. No orbital infections were documented. Twenty subjects (12%) received no prophylactic antibiotic, and two (1%) received only one dose of antibiotics pre-operatively for surgery. For primary antibiotic, 136 subjects (79%) received oral antibiotics, and 14 (8%) received intravenous (IV) antibiotics (excluding cefazolin). Cephalexin and amoxicillin-clavulanate were the most prescribed oral antibiotics that are equally effective. Five-to-seven day courses of antibiotics had no increased infections compared to ten-to-fourteen day courses. Calculated boundaries for effectiveness of prophylactic antibiotics ranged from a Number Needed to Treat (NNT) of 75 to a Number Needed to Harm (NNH) of 198. Conclusion: Antibiotics for prevention of orbital infection in patients with orbital fractures have become widely used. Coordination between trauma teams and specialists is needed to prevent patient overmedication and antibiotic resistance. Should antibiotics be used, shorter courses and avoidance of broad spectrum agents are recommended. Additional studies are needed. PMID:28400887

  11. The Comprehensive AOCMF Classification System: Orbital Fractures - Level 3 Tutorial

    PubMed Central

    Kunz, Christoph; Audigé, Laurent; Cornelius, Carl-Peter; Buitrago-Téllez, Carlos H.; Rudderman, Randal; Prein, Joachim

    2014-01-01

    The AOCMF Classification Group developed a hierarchical three-level craniomaxillofacial classification system with increasing level of complexity and details. Within the midface (level 1 code 92), the level 2 system describes the location of the fractures within defined regions in the central and lateral midface including the internal orbit. This tutorial outlines the level 3 detailed classification system for fractures of the orbit. It depicts the orbital fractures according to the subregions defined as orbital rims, anterior orbital walls, midorbit, and apex. The system allows documentation of the involvement of specific orbital structures such as inferior orbital fissure, internal orbital buttress, the greater wing of sphenoid, lacrimal bone, superior orbital fissure, and optic canal. The classification system is presented along with rules for fracture location and coding, a series of case examples with clinical imaging and a general discussion on the design of this classification. PMID:25489393

  12. Orbital fractures: role of imaging.

    PubMed

    Caranci, Ferdinando; Cicala, Domenico; Cappabianca, Salvatore; Briganti, Francesco; Brunese, Luca; Fonio, Paolo

    2012-10-01

    The orbit may be injured directly or indirectly. Blunt and penetrating trauma occurs with equal frequency. Soft tissue swelling often obscures direct clinical evaluation of the globe, limits ocular motion, and may limit clinical assessment of vision. Plain film radiographs of the orbits and sinuses are rarely used for diagnosis in orbital trauma. Computed tomography is considered the imaging modality of choice in this circumstance, as it is deemed to be the most accurate method in detecting fractures. The protocol is based on obtaining thin-section axial scans and multiplanar reformatted images, both are useful tools to guide treatment. Orbital fractures are not considered an ophthalmologic emergency unless there is visual impairment or globe injury. Surgical repair is indicated for patients who have persistent diplopia or cosmetic concerns (enophthalmos) and generaly is not performed until swelling subsides 7-10 days after injury. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Orbital blowout fractures: experimental evidence for the pure hydraulic theory.

    PubMed

    Rhee, John S; Kilde, John; Yoganadan, Narayan; Pintar, Frank

    2002-01-01

    The mechanism of injury and the underlying biomechanics of orbital blowout fractures remain controversial. The "hydraulic" theory proposes that a generalized increased orbital content pressure results in direct compression and fracturing of the thin orbital bone. To examine the pure hydraulic mechanism of injury by eliminating the factor of globe-to-wall contact and its possible contribution to fracture thresholds and patterns. Five fresh human cadaver specimens were used for the study. In each cadaver head, 1 orbit was prepared to mimic the normal physiologic condition by increasing the hypotony of the cadaver globe to normal intraocular pressure (15-20 mm Hg) with intravitreous injection of isotonic sodium chloride solution (saline). The second orbit served as a "hydraulic control," whereby the globe and orbital contents were exenterated and replaced by a saline-filled balloon at physiologic intraocular pressure. A 1-kg pendulum measuring 2.5 cm in diameter was used to strike the cadaver heads. Drop heights ranged from 0.2 m to 1.1 m (1960 mJ to 10 780 mJ energy). Each head was struck twice, once to each orbit. Direct visualization, high-speed videography, and computed tomographic scans were used to determine injury patterns at various heights between the 2 orbits. A fracture threshold was found at a drop height of 0.3 m (2940 mJ). Fracture severity and displacement increased with incremental increases in drop height (energy). Fracture displacement, with herniation of orbital contents, was obtained at heights above 0.5 m (4900 mJ). Isolated orbital floor fractures were obtained at lower heights, with medial wall fractures occurring in conjunction with floor fractures at higher energies (> or =6860 mJ). The globe intact side and balloon (hydraulic control) side showed nearly identical fracture patterns and levels of displacement at each drop height. This study provides support for the "hydraulic" theory and evidence against the role of direct globe-to-wall contact

  14. [Computed tomography in cats with craniofacial trauma with regard to maxillary and orbital fractures].

    PubMed

    Wunderlin, N; Amort, K; Wigger, A; Klumpp, S; Biel, M; Eichner, G; Kramer, M

    2012-10-17

    Computed tomographic examination of the skull of cats with craniofacial trauma. Analysis of diagnostic findings with regard to the occurrence of isolated and combined maxillary and orbital fractures. Prospective study (August 2006 - June 2010): Computed tomography (CT) of the skull of cats with craniofacial trauma. Thirty-eight cats met the inclusion criteria. Breeds were 36 Domestic Shorthair cats, one Maine Coon and one Somali cat. Age at admission ranged from 11 to 187 months. The ratio of the numbers of males to females was 22:16 (1.4). Computed tomographic examination revealed a maxillary fracture in 27 (71%) animals. Sixteen (42%) cats had multiple maxillary fractures (≥2). Twenty-eight animals (74%) displayed orbital fractures. Combined maxillary and orbital fractures occurred in 26 (68%) patients. The odds ratio of this combined occurrence was 87 (p<0.001). Sixteen (57%) of 28 cats with orbital fractures showed multiple orbital fractures (≥2). The incidence of bilateral orbital fractures was 67% (25 patients). The medial orbital wall was the most commonly fractured orbital wall (66%), and the orbital floor the second most common (61%). Computed tomographic examination of the skull of cats with craniofacial trauma showed that maxillary and orbital fractures are more common than previously described. Combined maxillary and orbital fractures occurred in more than half of the patients. In cats, orbital fractures mainly affect the medial orbital wall and the orbital floor. Cats with craniofacial trauma often have maxillary and orbital fractures. The additional information taken from the computed tomographic examination could lead to an optimised therapeutical concept.

  15. Transconjunctival preseptal approach for orbital floor and infraorbital rim fracture.

    PubMed

    Santosh, B S; Giraddi, Girish

    2011-12-01

    To evaluate the transconjunctival preseptal approach for time required for exposure, adequacy of exposure, intraoperative and postoperative complications. Materials for this study involved 15 cases of maxillofacial injuries with orbital floor and infraorbital rim fracture. The average exposure time taken for placement of incision till the exposure of the fracture was 21 min. Exposure obtained for fracture site was adequate in all cases, for the reduction of orbital floor and internal fixation of infraorbital rim. No cases had intraoperative and postoperative complications. In all cases postoperative esthetic outcome was satisfactory. The transconjunctival preseptal approach is most effective surgical access to infraorbital rim and orbital floor and even to medial orbital wall. This approach is surgically similar in providing exposure and access, but aesthetically superior to other approaches and has minimal complications. There are no disadvantages to transconjunctival preseptal approach, if performed meticulously with sound knowledge of anatomy of periorbital tissues.

  16. Reconstruction of internal orbital fractures with Vitallium mesh.

    PubMed

    Sargent, L A; Fulks, K D

    1991-07-01

    Trauma to the face frequently results in internal orbital fractures that may produce large orbital defects involving multiple walls. Accurate anatomic reconstruction of the bony orbit is essential to maintain normal appearance and function of the eye following such injuries. Autogenous bone grafts do not always produce predictable long-term support of the globe. Displacement and varying amounts of bone-graft resorption can lead to enophthalmos. This study examines the use of Vitallium mesh in the acute reconstruction of internal orbital defects. Fifty-four patients with 66 orbits underwent reconstruction of internal orbital defects with Vitallium mesh. Associated fractures were anatomically reduced and rigidly fixed. Forty-six patients and 57 orbits had adequate follow-up for analysis of results. The average follow-up was 9 months, with 85 percent of the patients followed 6 months or longer. There were no postoperative orbital infections, and none of the Vitallium mesh required removal. Large internal orbital defects can be reconstructed using Vitallium mesh with good results and little risk of infection. Vitallium mesh appears to be well tolerated in spite of free communication with the sinuses. Stable reconstruction of the internal orbit can be achieved and predictable eye position maintained without donor-site morbidity.

  17. COMPUTED TOMOGRAPHY IMAGING STRATEGIES AND PERSPECTIVES IN ORBITAL FRACTURES

    PubMed Central

    dos Santos, Denise Takehana; Oliveira, Jefferson Xavier; Vannier, Michael Walter; Cavalcanti, Marcelo Gusmão Paraíso

    2007-01-01

    Objective: The objective of this study was to demonstrate the sensitivity and specificity of multislice computed tomography (CT) for diagnosis of orbital fractures following different protocols, using an independent workstation. Materials and methods: CT images of 36 patients with maxillofacial fractures (symptomatic to orbit region) who were submitted to multislice CT scanning were analyzed, retrospectively. The images were interpreted based on 5 protocols, using an independent workstation: 1) axial (original images); 2) multiplanar reconstruction (MPR); 3) 3D images; 4) association of axial/MPR/3D images and 5) coronal images. The evaluated anatomical sites were divided according to the orbital walls: lateral (with or without zygomatic frontal process fracture); medial; superior (roof) and inferior (anterior, medial). The collected data were analyzed statistically using a validity test (Youden's J index; p<0.05). The clinical and/or surgical findings (medical records) were considered as the gold standard to corroborate the diagnosis of the anatomical localization of the orbital fracture. Results: 3D-CT scanning presented sensitivity of 78.9%, which was not superior to that of MPR (84.0%), axial/MPR/3D (90.5%) and coronal images (86.1%). On the other hand, the diagnostic value of axial images was considered limited for orbital fractures region, with sensitivity of 44.2%. Conclusions: Except for the axial images, which presented a low sensitivity, all methods evaluated in this study showed high specificity and sensitivity for the diagnosis of orbital fractures according to the proposed methodology. This protocol can add valuable information to the diagnosis of fractures using the association of axial/MPR/3D with multislice CT. PMID:19089117

  18. Change of the orbital volume ratio in pure blow-out fractures depending on fracture location.

    PubMed

    Oh, Sang Ah; Aum, Jae Ho; Kang, Dong Hee; Gu, Ja Hea

    2013-07-01

    The purposes of this study were to observe bony orbital volume (OV) changes in pure blow-out fractures according to fracture location using a facial computed tomographic scan and to investigate whether the OV measurements can be used as a quantitative value for the evaluation of the surgical results of the acute blow-out fracture.Forty-five patients with unilateral pure blow-out fracture were divided into 3 groups: inferior (group I), inferior medial (group IM), and medial (group M) orbital wall fracture. The OV and the orbital volume ratio (OVR) were prospectively measured before and 6 months after surgery with the use of 3-dimensional computed tomographic scans, and the Hertel scale was measured with a Hertel exothalmometer.The preoperative OVR increased to the greatest extent in group IM, and the mean preoperative OVR was 121.46. The mean preoperative OVR in group I was significantly higher than that of group M (P = 0.005). The OV and OVR revealed a statistically significant decrease after the surgery (P = 0.000). The Hertel scale improved from -1.04 mm before the surgery to -0.78 mm after the surgery, but no significant difference was observed (P = 0.051).The OVR was useful as a quantitative value to evaluate pure blow-out fractures, compared with that of the Hertel scale. Fracture location-associated OVR studies are needed to make volume guidelines of blow-out fracture surgery.

  19. Combined Orbital Fractures: Surgical Strategy of Sequential Repair

    PubMed Central

    Hur, Su Won; Kim, Sung Eun; Chung, Kyu Jin; Lee, Jun Ho; Kim, Tae Gon

    2015-01-01

    Background Reconstruction of combined orbital floor and medial wall fractures with a comminuted inferomedial strut (IMS) is challenging and requires careful practice. We present our surgical strategy and postoperative outcomes. Methods We divided 74 patients who underwent the reconstruction of the orbital floor and medial wall concomitantly into a comminuted IMS group (41 patients) and non-comminuted IMS group (33 patients). In the comminuted IMS group, we first reconstructed the floor stably and then the medial wall by using separate implant pieces. In the non-comminuted IMS group, we reconstructed the floor and the medial wall with a single large implant. Results In the follow-up of 6 to 65 months, most patients with diplopia improved in the first-week except one, who eventually improved at 1 year. All patients with an EOM limitation improved during the first month of follow-up. Enophthalmos (displacement, 2 mm) was observed in two patients. The orbit volume measured on the CT scans was statistically significantly restored in both groups. No complications related to the surgery were observed. Conclusions We recommend the reconstruction of orbit walls in the comminuted IMS group by using the following surgical strategy: usage of multiple pieces of rigid implants instead of one large implant, sequential repair first of the floor and then of the medial wall, and a focus on the reconstruction of key areas. Our strategy of step-by-step reconstruction has the benefits of easy repair, less surgical trauma, and minimal stress to the surgeon. PMID:26217562

  20. Diplopia secondary to orbital fracture in adults.

    PubMed

    Pérez-Flores, I; Santos-Armentia, E; Fernández-Sanromán, J; Costas-López, A; Fernández-Ferro, M

    2017-09-08

    To evaluate the incidence and evolution of diplopia as a complication of orbital fractures in adults. A review was conducted on medical records of all consecutive adults with orbital fracture referred between January 2014 and December 2015. An analysis was made of the incidence of diplopia secondary to fracture in the acute phase and its evolution. A descriptive study was performed on the variables related to patients, fractures, and fracture and diplopia treatment. The study included 39patients with a mean age of 48years (17-85). Of all the patients, 17 (43.6%) presented with diplopia in the acute phase. Differences were found between the groups with and without diplopia in relation to muscle entrapment diagnosed by orbital computed tomography, duction limitation, and fracture surgery ≤1week (P=.02, P=.00, P=.04, respectively). Out of the 17patients with diplopia, 12 had a mean follow-up of 18weeks (1-72), and in 10 (83.3%) diplopia was resolved in a mean time of 10weeks (1-72). There were spontaneous resolution in 4 (33.3%) patients, and resolution after fracture surgery in 4 (57%) of the 7 that underwent surgery. In 4cases (33.3%) prisms were prescribed, and 2 (16.6%) required strabismus surgery. Diplopia secondary to orbital fracture in adults is frequent, but it is resolved in most cases spontaneously or after fracture surgery. A few patients will require prisms and/or strabismus surgery. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Medial Orbital Wall Reconstruction With Porous Polyethylene by Using a Transconjunctival Approach With a Caruncular Extension.

    PubMed

    Chou, Chieh; Kuo, Yur-Ren; Chen, Chien-Chang; Lai, Cheng-Sheng; Lin, Sin-Daw; Huang, Shu-Hung; Lee, Su-Shin

    2017-03-01

    The reported rate of isolated medial orbital wall fractures varies widely but has been found to be as high as 55% of all orbital fractures. Identifying and repairing medial orbital wall defects by using appropriate materials improves patient outcome considerably; however, most related research has focused on orbital floor defect management rather than medial orbital wall treatment, and no consensus on repairing medial orbital wall fractures exists. Furthermore, medial orbital wall fracture is a main cause of posttraumatic enophthalmos. In this study, we introduce a modified surgical technique for repairing large medial wall fractures stably, also reviewed relevant literature and established an algorithm for managing medial orbital wall fractures. We reviewed the outcomes of facial trauma patients who underwent facial bone reduction and internal fixation surgery in our hospital between October 1, 2010, and October 1, 2013. The patients were all treated medial orbital wall reconstruction with porous polyethylene by using a transconjunctival approach with a caruncular extension for large medial orbital wall fractures. Medical records and radiologic images of the patients were reviewed retrospectively. The outcomes evaluated were trauma mechanism, clinical findings of ocular injury, preoperative and postoperative ocular symptoms, degree of enophthalmos, and orbital volume restoration after surgery. Transconjunctival approach with a caruncular extension was performed without any complications. The incidence of diplopia was 47.4% and enophthalmos (>2 mm) was 31.6%, with no significant diplopia and enophthalmos after surgery. Patients were symptom-free on follow-up. The average enophthalmos was successfully corrected from 0.88 mm preoperatively to 0.26 mm and orbital volume was corrected from 26.22 to 22.99 cm after surgery; these results also showed P less than 0.001. The current results suggest that the proposed method of medial orbital wall reconstruction, in which

  2. Focusing of eruptions by fracture wall erosion

    NASA Astrophysics Data System (ADS)

    Hieronymus, Christoph F.; Bercovici, David

    Lithospheric flexural stresses beneath volcanic loads are horizontally strongly compressive towards the top of the lithosphere. Thus, while magma transport through the brittle lithosphere occurs via fractures, the fracture paths under the volcanic center are predicted by stress trajectories to be horizontal and thus unable to supply melt to the volcanic edifice where eruptions are observed. Moreover, the magnitude of the compressive stresses under large loads would close down any vertical magma paths. Both problems may be resolved by additional stresses due to melting or thermomechanical erosion of fracture walls developing over the life-span of the volcano. Fractures form and close frequently in the seismogenic zone of the lithosphere, with each fracture eroding away a small amount of material. The total amount of material removed makes the stress field more tensile, thereby facilitating the long-lived and vertically oriented magma pathways necessary to build discrete volcanic structures.

  3. Orbital hematoma caused by bleeding from orbital branch of the infraorbital artery after reconstruction of an orbital fracture.

    PubMed

    Hwang, Kun; Kim, Joo Ho; Kang, Young Hye

    2014-03-01

    We experienced and report on a case of retrobulbar hematoma caused by bleeding from the orbital branch of the infraorbital artery after a medial orbital wall reconstruction.A healthy 28-year-old man struck his left eye while playing baseball before admission. A computed tomographic scan revealed an approximately 13 × 12-mm-sized fracture of the left orbit medial wall. The medial orbit wall was reconstructed through a subciliary approach on the 18th day after the injury. Approximately 15 hours after the orbit wall reconstruction, the patient complained of pain in the left orbital area, headache, and vomiting. Upon an examination, swelling and ecchymosis were observed on the left eye. His visual acuity was 0.8 (oculus dexter [OD])/0.4 (oculus sinister [OS]) and the intraocular pressure was 18 (OD)/24 (OS) mm Hg by a Goldmann applanation tonometry. A computed tomographic scan showed an intraorbital hematoma and proptosis on the left side. In an emergency operation, a hematoma with a volume of approximately 2 to 3 mL was evacuated and an active bleeding point was noted on the orbital floor, which was thought to be the orbital branch of the infraorbital nerve. The bleeding point was cauterized. After the operation, his visual acuity was 1.0 (OD)/0.8 (OS) and the ocular pressure normalized to 16 (OD)/16 (OS) mm Hg by a Goldmann applanation tonometry.Close observation and meticulous hemostasis along the infraorbital groove may be needed in an orbital floor exploration to prevent postoperative orbital hematoma.

  4. MR imaging of orbital blow-out fractures.

    PubMed

    McArdle, C B; Amparo, E G; Mirfakhraee, M

    1986-01-01

    We report on a case of orbital blow-out fractures involving the medial and inferior walls. In this case conventional multiplanar 8 mm thick sections with magnetic resonance (MR) imaging proved to be more helpful than 1.5 mm axial thin sections with CT in demonstrating the extent of orbital floor herniation of fat. Entrapment of muscle was excluded. Oblique sagittal views were most helpful in evaluating the orbital floor, since the full course of the inferior rectus muscle is seen. Additionally, the optic nerve is seen along its entire length. Masking of intraorbital contents by isodense hemorrhage on CT studies apparently is not a problem with MR imaging if hemorrhage is small or nonacute.

  5. Management of orbital fractures: challenges and solutions

    PubMed Central

    Boyette, Jennings R; Pemberton, John D; Bonilla-Velez, Juliana

    2015-01-01

    Many specialists encounter and treat orbital fractures. The management of these fractures is often challenging due to the impact that they can have on vision. Acute treatment involves a thorough clinical examination and management of concomitant ocular injuries. The clinical and radiographic findings for each individual patient must then be analyzed for the need for surgical intervention. Deformity and vision impairment can occur from these injuries, and while surgery is intended to prevent these problems, it can also create them. Therefore, surgical approach and implant selection should be carefully considered. Accurate anatomic reconstruction requires complete assessment of fracture margins and proper implant contouring and positioning. The implementation of new technologies for implant shaping and intraoperative assessment of reconstruction will hopefully lead to improved patient outcomes. PMID:26604678

  6. [Correction of enophthalmos deformity caused by orbital blow-out fractures using medpor implantation].

    PubMed

    Li, Teng; Min, Ren; Lai, Gui

    2005-07-01

    To study the surgical reconstruction for correction of enophthalmos deformity caused by orbital blow-out fractures. From December 1996 to March 2004, 56 cases of enophthalmos deformity caused by orbital blow-out fracture were repaired. There were 37 cases diplopia, 35 cases with worsened visual acuity than pre-trauma. Typical sub-ciliary incision was employed to expose the fractured area. The dissection was done beneath the medial and inferior orbital periosteum. The fracture areas were exposed and the tissues protrusion to maxillary sinus were released through the space between fractured bones. After the medial and inferior orbital walls and orbital floors were exposed,the herniated orbital contents were released and reduced to the orbital cavity. The fractured orbital walls were repaired precisely with Medpor which were fixed to the area beneath the periosteum with 2 plates at least. All 56 cases of enophthalmos deformity caused by orbital blow-out fracture repaired with this technique recovered well and their facial appearance improved greatly. With a follow-up ranged from 2 months to 5 years, the degree of enophthalmos stabilized at within 2 mm, no relapse and other complications occurred. Of 34 patients with diplopia, 27 were improved. Of the 35 cases with worsened visual acuity, 9 were improved with different degree. No diplopia or visual acuity worsening occurred. It is safe and effective to correct the orbital blow-out fractures. The earlier it is repaired, the better the effect will be. Medpor with its advantages like better histocompatibility, easier sculpturing, moderate hardness, lower absorptivity, fewer complications and permanence effect is the preferable implantation material for correcting enophthalmos deformity.

  7. Proposed three-dimensional model of the orbit and relevance to orbital fracture repair.

    PubMed

    Fitzhugh, Alexander; Naveed, Hasan; Davagnanam, Indran; Messiha, Ashraf

    2016-07-01

    To describe the relationship of the orbital rim and depth in Far Eastern skulls by anatomical study, using morphometry to yield an octagonal three-dimensional model of the orbit. Forty-one orbits of 21 Far Eastern skulls from the Department of Anatomy of St George's, University of London were included in this study. A morphometric study was conducted, measuring between eight reproducible orbital rim landmarks to yield perimeters, and from these landmarks to the optic canal to yield orbital depth. Orbital height and width were also recorded. Results were statistically analysed to look for evidence of gender variation or laterality before comparison with those from other ethnicities. The authors then present a method for three-dimensional description of the orbit. 67 % of orbits were male. Orbital height and width were significantly greater in males (34.6 ± 2.0 and 39.4 ± 1.7, vs. 32.5 ± 2.3 and 37.2 ± 2.4 mm). Orbital perimeter tended towards being larger in males (126.3 vs. 122.2 mm, p = 0.05), as was the angle between medial and lateral walls (50.1° ± 2.0°, vs. 47.9° ± 3.0°). This study has proposed a new method for describing the orbit using three-dimensional measurements, yielding clinically useful morphometric data. These results and model have applications in surgical navigation of the orbit, repair of fractures, and prediction of post-traumatic or surgical enophthalmos.

  8. Blow-out fractures of the orbit: a comparison of computed tomography and conventional radiography with anatomic correlation

    SciTech Connect

    Hammeschlag, S.B.; Hughes, S.; O'Reilly, G.V.; Naheedy, M.H.; Rumbaugh, C.L.

    1982-05-01

    Orbital blow-out fractures were experimentally created in eight human cadavers. Each orbit underwent conventional radiographic studies, complex motion tomography, and computed tomographic examinations. A comparison of the three modalities was made. Anatomical correlation was obtained by dissecting the orbits. The significance of medial-wall fractures and enophthalmos is discussed. Limitation of inferior rectus muscle mobility is thought to be a result of muscle kinking associated with orbital fat-pad prolapse at the fracture site, rather than muscle incarceration. Blow-out fractures should be evaluated by computed tomographic computer reformations in the oblique sagittal plane.

  9. Buckling and hydraulic mechanisms in orbital blowout fractures: fact or fiction?

    PubMed

    Ahmad, Fateh; Kirkpatrick, Niall A; Lyne, Jonathan; Urdang, Michael; Waterhouse, Norman

    2006-05-01

    Since the first description of orbital blowout fractures, there has been much confusion as to their etiology. Two principal mechanisms have been proposed to explain their production, the buckling and the hydraulic mechanisms caused, respectively, by trauma to the orbital rim and the globe of the eye. The aim of this study was to evaluate both mechanisms qualitatively and quantitatively. Our protocol used intact cadavers, quantifiable intraocular pressure, variable and quantifiable force, and quantifiable bone strain distribution with strain gauge analysis. One orbit of each cadaver was used to simulate each of the two mechanisms, allowing direct comparison. Fractures produced by the buckling mechanism were limited to the anterior part of the orbital floor, with strain readings reaching up to 3756 microepsilon. Posteriorly, strain did not exceed 221 microepsilon. In contrast, hydraulic-type fractures were much larger, involving anterior and posterior parts of the floor as well as the medial wall of the orbit. Here, strain exceeded 3756 microepsilon in both parts of the floor. Furthermore, we have demonstrated that the average energy required to fracture the orbital floor by the buckling mechanism is 1.54 J, whereas an average energy of 1.22 J is needed to produce this fracture by the hydraulic mechanism. Our results suggest that efforts to establish one or another mechanism as the primary etiology are misplaced. Both mechanisms produce orbital blowout fractures, with different and specific characteristics. We believe this provides the basis for our reclassification of such fractures.

  10. Antiferromagnetic Domain Wall Motion Driven by Spin-Orbit Torques.

    PubMed

    Shiino, Takayuki; Oh, Se-Hyeok; Haney, Paul M; Lee, Seo-Won; Go, Gyungchoon; Park, Byong-Guk; Lee, Kyung-Jin

    2016-08-19

    We theoretically investigate the dynamics of antiferromagnetic domain walls driven by spin-orbit torques in antiferromagnet-heavy-metal bilayers. We show that spin-orbit torques drive antiferromagnetic domain walls much faster than ferromagnetic domain walls. As the domain wall velocity approaches the maximum spin-wave group velocity, the domain wall undergoes Lorentz contraction and emits spin waves in the terahertz frequency range. The interplay between spin-orbit torques and the relativistic dynamics of antiferromagnetic domain walls leads to the efficient manipulation of antiferromagnetic spin textures and paves the way for the generation of high frequency signals from antiferromagnets.

  11. Antiferromagnetic domain wall motion driven by spin-orbit torques

    PubMed Central

    Shiino, Takayuki; Oh, Se-Hyeok; Haney, Paul M.; Lee, Seo-Won; Go, Gyungchoon; Park, Byong-Guk; Lee, Kyung-Jin

    2016-01-01

    We theoretically investigate dynamics of antiferromagnetic domain walls driven by spin-orbit torques in antiferromagnet/heavy metal bilayers. We show that spin-orbit torques drive antiferromagnetic domain walls much faster than ferromagnetic domain walls. As the domain wall velocity approaches the maximum spin-wave group velocity, the domain wall undergoes Lorentz contraction and emits spin-waves in the terahertz frequency range. The interplay between spin-orbit torques and the relativistic dynamics of antiferromagnetic domain walls leads to the efficient manipulation of antiferromagnetic spin textures and paves the way for the generation of high frequency signals from antiferromagnets. PMID:27588878

  12. Mechanisms of orbital floor fractures: a clinical, experimental, and theoretical study.

    PubMed Central

    Bullock, J D; Warwar, R E; Ballal, D R; Ballal, R D

    1999-01-01

    PURPOSE: The purpose of this study was to investigate the two accepted mechanisms of the orbital blow-out fracture (the hydraulic and the buckling theories) from a clinical, experimental, and theoretical standpoint. METHODS: Clinical cases in which blow-out fractures resulted from both a pure hydraulic mechanism and a pure buckling mechanism are presented. Twenty-one intact orbital floors were obtained from human cadavers. A metal rod was dropped, experimentally, onto each specimen until a fracture was produced, and the energy required in each instance was calculated. A biomathematical model of the human bony orbit, depicted as a thin-walled truncated conical shell, was devised. Two previously published (by the National Aeronautics Space Administration) theoretical structural engineering formulas for the fracture of thin-walled truncated conical shells were used to predict the energy required to fracture the bone of the orbital floor via the hydraulic and buckling mechanisms. RESULTS: Experimentally, the mean energy required to fracture the bone of the human cadaver orbital floor directly was 78 millijoules (mj) (range, 29-127 mj). Using the engineering formula for the hydraulic theory, the predicted theoretical energy is 71 mj (range, 38-120 mj); for the buckling theory, the predicted theoretical energy is 68 mj (range, 40-106 mj). CONCLUSION: Through this study, we have experimentally determined the amount of energy required to fracture the bone of the human orbital floor directly and have provided support for each mechanism of the orbital blow-out fracture from a clinical and theoretical basis. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5A FIGURE 5B FIGURE 5E FIGURE 5F PMID:10703119

  13. Ocular and periocular injuries associated with an isolated orbital fracture depending on a blunt cranial trauma: anatomical and surgical aspects.

    PubMed

    Karabekir, H Selim; Gocmen-Mas, Nuket; Emel, Erhan; Karacayli, Umit; Koymen, Ramazan; Atar, Elmas Kagnici; Ozkan, Nezih

    2012-10-01

    The anatomical location of fractures following blunt cranio-orbital trauma is important for neurosurgeons and maxillofacial surgeons. In this study, 588 cranio-orbital fractures following blunt trauma were evaluated retrospectively with regard to the anatomical site and surgical treatment. Orbital cranial nerve injuries and the outcomes of the medical and/or surgical treatment are described. Distribution of the zygomatic complex and orbital fractures were as follows: zygomatic complex fractures (n:304), isolated orbital fractures (n:58), complex comminuted fractures (n:226). In 58 cases, 69 orbit fractures were found (11 bilateral and 47 unilateral fractures). The lateral wall was the most frequent fracture (n:63). The least frequent fracture was the roof of the orbit (n:11). The accompanying lesions were as follows: 89.65% of cases were associated with periorbital haematoma (n:52), 13.79% of cases with retrobulbar haemorrhage (n:8), 96.55% cases with periorbital soft tissue oedema (n:56), 53.45% cases with pneumocephalus (n:31), 8.62% cases with intra-parenchymal contusion (n:5), 6.89% cases with enophthalmia (n:4), 5.17% of cases with rhinorrhoea (n: 3), 5.17% cases with optic bulb injury and adnexial trauma (n:3), 32.76% cases with intra-orbital emphysema (n:19), and 20.69% with vision dysfunctions (n:12), of whom 2 had no optic nerve injury. Copyright © 2011 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  14. Orbital stress analysis, Part IV: Use of a "stiffness-graded" biodegradable implants to repair orbital blow-out fracture.

    PubMed

    Al-Sukhun, Jehad; Penttilä, Heikki; Ashammakhi, Nureddin

    2012-01-01

    healing, as well as higher tensile stress in the intact portion of the bone. It seems that this is the first reported study, in the literature, on the use of SG biodegradable implants to repair and promote bone healing at the fracture site of the inferior orbital wall bone defect.

  15. In Situ Splitting of a Rib Bone Graft for Reconstruction of Orbital Floor and Medial Wall.

    PubMed

    Uemura, Tetsuji; Yanai, Tetsu; Yasuta, Masato; Harada, Yoshimi; Morikawa, Aya; Watanabe, Hidetaka; Kurokawa, Masato

    2017-06-01

    In situ splitting of rib bone graft was conducted in 22 patients for the repair of orbital fracture with no other complicating fractures. A bone graft was harvested from the sixth or seventh rib in the right side. The repair of the orbital floor and medial wall was successful in all the cases. Ten patients had bone grafting to the orbital floor, eight had it done onto medial wall, and 4 onto both floor and wall after reduction. The mean length of in situ rib bone graft was 40.9 mm (range, 20-70 mm), the mean width of these was 14.9 mm (range, 8-20 mm). The bone grafting was done by one leaf for 15 cases and two leafs for 7 cases in size of defects. The technique of in situ splitting of a rib bone graft for the repair of the orbital floor and medial wall is a simple and safe procedure, easily taking out the in situ splitting of a rib, and less pain in donor site. It has proved to be an optimal choice in craniofacial reconstruction, especially the defects of orbital floor and medial wall.

  16. Traumatic globe luxation associated with orbital fracture in a child: a case report and literature review.

    PubMed

    Amaral, Márcio Bruno Figueiredo; Carvalho, Matheus Furtado; Ferreira, André Baptista; Mesquita, Ricardo Alves

    2015-03-01

    Orbital fracture associated with traumatic globe luxation is rare, as it generally requires trauma with high energy for this to occur. The present case report focused on a child who had been hit by a motorcycle, leading to a globe luxation of the left eye and fractures of the superolateral orbital walls. The patient presented initial cosmetic and psychological benefits from the repositioning of the intact globe and the reduction of the orbital fractures. However, a subsequent evisceration of the globe was required due to persistent proptosis and pain. An ocular prosthesis was also implanted, thus recovering the patient's aesthetics. Thirty-four well-documented cases of traumatic globe luxation could be found in the English literature since 1970. The mean age of patients presenting traumatic globe luxation was 29.5 years. The male gender proved to be more prevalent, with traffic collisions representing the most common accident etiology. Direct orbital trauma with fractures of medial and floor walls displacing the globe into the maxillary sinus represented the most common injury mechanism (38.2 %), followed by an elongated object entering the orbit (26.5 %). Optical nerve avulsion is the most serious complication seen in association with traumatic globe luxation, with the repositioning of the initial globe, with no enucleation or evisceration, representing the main form of management.

  17. The late treatment of vertical orbital dystopia resulting from an orbital roof fracture.

    PubMed

    Horowitz, J H; Persing, J A; Winn, H R; Edgerton, M T

    1984-12-01

    Traumatic fracture of the orbital roof is uncommon and it may be unrecognized at the time of injury. In this article we describe a patient with progressive vertical orbital dystopia four years after he sustained a fracture of his "frontal" bone. Surgical exploration revealed an orbital roof fracture complicated by a chronic dural leak. An intracranial-extracranial approach through a modified frontal craniotomy provided excellent visualization to elevate the bony orbit and globe safely and repair the dural tear. Our study illustrates the need to correct residual soft tissue deformity at a second operation. Orbital roof fracture is a complex injury and is best treated by a multispecialty team using the methods learned from the treatment of patients with congenital orbital dystopia.

  18. Post-ablative reconstruction of the medial canthus and medial orbital wall using conchal cartilage graft with three illustrative cases.

    PubMed

    Dagregorio, G; Darsonval, V

    2005-12-01

    When the medial third of the upper or lower eyelid has to be reconstructed after full-thickness tumour excision, we usually use Hübner tarsomarginal grafts, but when medial canthal lesions spread to the medial orbital wall without invading the orbital margin, conchal graft becomes our first surgical option. Previously reported solutions to this difficult problem are few and concern more directly medial orbital wall fractures. We found no article dealing specifically with the use of conchal graft in post-ablative reconstruction of the medial orbital wall. Nevertheless the concha presents great advantages over bone grafting or rib cartilage, because it is more flexible and malleable. And it is less prone to extrusion or infection as may be allografts implants. It is a very effective way to repair medial orbital defects, but graft reorientation must be perfect to match exactly the medial orbital wall concavity.

  19. Maxillary antral bone grafts for repair of orbital fractures.

    PubMed

    Copeland, M; Meisner, J

    1991-04-01

    Use of bone from the maxillary antrum to repair defects in the orbital floor was described more than 20 years ago but has not been reported for correction of orbital rim fractures. The method is appealing because the source is contiguous with the recipient site; enhanced exposure might allow better fracture reduction and evacuation of debris and hematoma from the maxillary sinus. The intraoral approach also avoids an external incision and scar, prevents such complications as pneumothorax or dural perforation, and reduces postoperative pain. In 60 cases of orbital and zygomatic complex fractures seen between 1985 and 1990, less than 8% required more extensive graft material than the maxillary antra could provide. To assess the potential advantages of local over extraanatomical bone grafts, we evaluated maxillary antral bone grafts obtained through buccal sulcus incisions in 14 patients for restoration following fractures of the orbit. Several of these patients are described. Bone union was complete in all patients and there was no morbidity related to infection, oroantral fistula formation, dehiscence, or disfigurement. Sufficient bone was available from the uninvolved contralateral side to repair even severely comminuted fractures. In zygomatic complex fractures, maxillary antral grafts appeared to provide additional strength in the region of the fractured maxillary buttress. The success of the procedure in our experience, coupled with the safety of bone harvesting from this source, and the avoidance of an external scar make maxillary antral bone well suited to reconstruction of all areas of the orbit.

  20. Long-term infectious complications of using porous polyethylene mesh for orbital fracture reconstruction

    PubMed Central

    Song, Xuefei; Li, Lunhao; Sun, Yiyuan; Fan, Xianqun; Li, Zhengkang

    2016-01-01

    Abstract Porous polyethylene is a widely used implants in orbital reconstruction, on which comprehensive clinical analysis, various treatments, and different prognosis according to specific classification principles on long-term complications have not been reported. To investigate the new clinical symptoms, intraoperative findings, treatments, and outcomes of complications long period after previous surgery, resulting from the use of porous polyethylene mesh for orbital fracture reconstruction. A retrospective study was conducted on 21 patients at the Department of Ophthalmology, Shanghai Ninth People's Hospital with orbital complications after orbital fracture reconstruction with porous polyethylene mesh for 4 ± 2.2 years from 2011 to 2013. These data included new clinical symptoms after previous surgery, computerized tomography data, intraoperative findings, treatments, and outcomes. Data from 21 patients were analyzed in this study. Two patients received conservative treatment, while the other 19 patients underwent surgical approaches. Classification principles for orbital complications after orbital wall defect reconstruction with porous polyethylene mesh were formulated according to patients’ new clinical symptoms, computed tomography (CT), and intraoperative findings after previous surgery. In the last follow-up, 19 patients (90.5%) were cured or improved according to our assessment principle. The follow-up ranged from 3 to 45 months (35 months in average). According to specific classification for orbital complications resulting from the use of porous polyethylene mesh for orbital fracture reconstruction, various medical treatments should be carried out, and the prognosis may be different. PMID:27336867

  1. Long-term infectious complications of using porous polyethylene mesh for orbital fracture reconstruction.

    PubMed

    Song, Xuefei; Li, Lunhao; Sun, Yiyuan; Fan, Xianqun; Li, Zhengkang

    2016-06-01

    Porous polyethylene is a widely used implants in orbital reconstruction, on which comprehensive clinical analysis, various treatments, and different prognosis according to specific classification principles on long-term complications have not been reported.To investigate the new clinical symptoms, intraoperative findings, treatments, and outcomes of complications long period after previous surgery, resulting from the use of porous polyethylene mesh for orbital fracture reconstruction.A retrospective study was conducted on 21 patients at the Department of Ophthalmology, Shanghai Ninth People's Hospital with orbital complications after orbital fracture reconstruction with porous polyethylene mesh for 4 ± 2.2 years from 2011 to 2013. These data included new clinical symptoms after previous surgery, computerized tomography data, intraoperative findings, treatments, and outcomes.Data from 21 patients were analyzed in this study. Two patients received conservative treatment, while the other 19 patients underwent surgical approaches. Classification principles for orbital complications after orbital wall defect reconstruction with porous polyethylene mesh were formulated according to patients' new clinical symptoms, computed tomography (CT), and intraoperative findings after previous surgery. In the last follow-up, 19 patients (90.5%) were cured or improved according to our assessment principle. The follow-up ranged from 3 to 45 months (35 months in average).According to specific classification for orbital complications resulting from the use of porous polyethylene mesh for orbital fracture reconstruction, various medical treatments should be carried out, and the prognosis may be different.

  2. Chronic subperiosteal hematic cyst formation twelve years after orbital fracture repair with alloplastic orbital floor implant.

    PubMed

    Glavas, Ioannis; Lissauer, Boaz; Hornblass, Albert

    2005-03-01

    An 89-year-old female patient with a history of a left orbital floor fracture repair with synthetic implant 12 years prior, presented with a three-week history of blurry vision, inferior conjunctival chemosis and proptosis of the left eye. CT scan revealed a well-circumscribed subperiosteal lesion with superior elevation of the orbital floor implant. The patient underwent transconjunctival orbital surgery with removal of the implant and drainage of the subperiosteal hemorrhagic cyst. The patient had an uncomplicated postoperative course, with resolution of the proptosis, chemosis, and return of normal vision. This case represents an unusual late complication of orbital fracture repair with associated reduced visual acuity.

  3. Incidence of depression of the medial orbital wall without a recent trauma event.

    PubMed

    Hwang, Kun; Kim, Han Joon; Park, Joo Won; Lee, Seong Sim; Kim, Hyeon Jeong; Tae, Na Yeong

    2014-09-01

    The aim of this study was to see how frequently depression of the orbital medial wall can be found on computed tomographic (CT) imaging of patients without a recent trauma event. A total of 14,628 CT scans (12,515 brain CT scans and 2113 three-dimensional facial CT scans) of patients with no recent trauma event (defined as a facial trauma within 1 mo) were reviewed. If there was a depression of more than 3 mm on the medial wall compared with the contralateral side in the axial view, the scan was included in the "depression or asymmetry" group. In the depression or asymmetry group, old fractures and recent fractures were differentiated according to the degree of swelling of the medial rectus muscle and soft tissue swelling. Among the 14,628 CT scans with no recent facial trauma event, 836 cases (5.7%) had depression or an asymmetric medial wall. Most (94.3%, 788 cases) of the 836 cases were discovered to have an old medial wall fracture, whereas 39 cases (4.7%) were reported to have a recent medial wall fracture despite not having a recent facial trauma event. Only 9 cases (1.1%) were revealed to have a mucocele. It is noteworthy that 5.3% (788 cases among the 14,628 cases) had an old medial wall fracture despite not having any facial trauma within 1 month. The reason for this relatively high ratio is thought to be because medial fractures are often undetected with conventional plain x-ray imaging.

  4. Comparative Orbital Volumes between a Single Incisional Approach and a Double Incisional Approach in Patients with Combined Blowout Fracture

    PubMed Central

    Park, Sang Wook; Seo, Bommie F.; Rhie, Jong Won; Ahn, Sang Tae; Oh, Deuk Young

    2015-01-01

    Purpose. Blowout fracture characterized by concurrent floor and medial wall fractures is a rare entity. We compared surgical outcomes between a single approach and a double approach in patients with orbital fracture by measuring the postoperative orbital volume. Methods. We confirmed that 21 (8.5%) of a total of 246 patients with orbital fractures had fractures of the medial wall and floor through a retrospective chart review. Of these, 10 patients underwent the single approach and the remaining 11 patients had the double approach. We performed a statistical analysis of changes between the preoperative and postoperative orbital volumes at a 6-month follow-up. Results. Compared with the contralateral, nonaffected side, the orbital volume was 115.3 (±6.09)% preoperatively and 106.5 (±6.15)% postoperatively in the single approach group and 118.2 (±11.16)% preoperatively and 108.6 (±13.96)% postoperatively in the double approach. These results indicated that there was a significant difference between the preoperative and postoperative orbital volumes in each group (P < 0.05). However there was no significant difference between the single approach and the double approach (P > 0.05). Conclusions. Our results showed that there were no significant differences in surgical outcomes between the two modalities. The treatment modality may be selected based on the surgeons' preference, as well as the fracture type. PMID:25961049

  5. Design complexity and fracture control in the equine hoof wall.

    PubMed

    Kasapi, M A; Gosline, J M

    1997-06-01

    Morphological and mechanical studies were conducted on samples of equine hoof wall to help elucidate the relationship between form and function of this complex, hierarchically organized structure. Morphological findings indicated a dependence of tubule size, shape and helical alignment of intermediate filaments (IFs) within the lamellae on the position through the wall thickness. The plane of the intertubular IFs changed from perpendicular to the tubule axis in the inner wall to almost parallel to the tubule axis in the outer wall. Morphological data predicted the existence of three crack diversion mechanisms which might prevent cracks from reaching the sensitive, living tissues of the hoof: a mid-wall diversion mechanism of intertubular material to inhibit inward and upward crack propagation, and inner- and outer-wall diversion mechanisms that prevent inward crack propagation. Tensile and compact tension fracture tests were conducted on samples of fully hydrated equine hoof wall. Longitudinal stiffness decreased from 0.56 to 0.30 GPa proceeding inwardly, whereas ultimate (maximum) properties were constant. Fracture toughness parameters indicated that no compromise results from the declining stiffness, with J-integral values ranging from 5.5 to 7.8 kJ m-2 through the wall thickness; however, highest toughness was found in specimens with cracks initiated tangential to the wall surface (10.7 kJ m-2). Fracture paths agreed with morphological predictions and further suggested that the wall has evolved into a structure capable of both resisting and redirecting cracks initiated in numerous orientations.

  6. Superior oblique muscle entrapment in orbital fracture presenting as acquired brown-like syndrome: a case report and review of literature.

    PubMed

    Adulkar, Namrata; Kim, Usha; Shetty, Shashikant

    2014-01-01

    Pediatric orbital trauma with fracture involving the junction of roof and medial wall leading to superior oblique entrapment is rare. Here the authors report a case of orbital fracture at the junction of roof and medial wall with entrapment of the superior oblique muscle presenting clinically as canine tooth syndrome which was surgically released. Postoperatively, the ocular motility improved, and the patient was relieved of diplopia. They recommend early surgical exploration in such cases, which lead to successful resolution of diplopia.

  7. Mechanisms of extraocular muscle injury in orbital fractures.

    PubMed

    Iliff, N; Manson, P N; Katz, J; Rever, L; Yaremchuk, M

    1999-03-01

    The gross and microscopic events that occur after orbital blowout fractures were evaluated to assess the mechanisms of diplopia and muscle injury. Intramuscular and intraorbital pressures were evaluated in experimental animals, in cadavers, and at the time of orbital fracture explorations for repair of orbital fractures in humans. Histologic and circulatory changes, muscle pressure recordings, and operative observations were evaluated. Creation of a compartment syndrome was evaluated to include a histologic evaluation of the orbital fibrous sheath network for the extraocular muscles and the intramuscular vasculature. These experiments and observations do not support the role of a compartment syndrome in ocular motility disturbances because (1) intramuscular pressures were subcritical in both humans and animals; (2) no limiting fascial compartment could be demonstrated; and (3) microangiograms and histologic evaluations did not confirm areas of compartmental ischemic necrosis. Muscle contusion, scarring within and around the orbital fibrous sheath network, nerve contusion, and incarceration within fractures remain the probable causes of diplopia, with the most likely explanations being muscle contusion and fibrosis or incarceration involving the muscular fascial network.

  8. Clinical effects of 3-D printing-assisted personalized reconstructive surgery for blowout orbital fractures.

    PubMed

    Fan, Bin; Chen, Han; Sun, Ying-Jian; Wang, Bei-Fen; Che, Lin; Liu, Shu-Yan; Li, Guang-Yu

    2017-08-07

    One of the key challenges during orbital fracture reconstructive surgery, due to the complex anatomy of the orbit, is shaping and trimming the precise contour of the implants. The objectives of this study were to describe and evaluate the use of a three-dimensional (3-D) printing technique for personalized reconstructive surgery for repairing orbital fractures. A total of 29 cases which had 3-D technique-assisted surgical reconstruction, and 27 cases which had traditional surgery, were retrospectively analyzed. Preoperative and postoperative CT images were measured using MIMICS software, and the contour of the fracture zone and the Medpor-titanium implant were analyzed and compared. The surgical duration was also compared between the two groups. There were statistically significant differences in the maximum width, depth and area between fracture zone and implant between the two groups, with the absolute value in the 3-D group markedly lower as compared to the control group. In addition, the difference in the medial-inferior wall angle between the surgical eye and healthy eye was also statistically significant between the groups. The average surgical duration in the 3-D group was substantially shorter than in the control group. Additionally, the postoperative clinical evaluation in the 3-D group was superior to that of the control group. The 3-D printing technique is of great value for predicting the precise fracture zone before, and during, personalized surgery, and can help surgeons achieve accurate anatomical reconstruction for repairs of blowout orbital fractures. Moreover, the simulated bone template produced by 3-D printing models allows for "true-to-original" orbital reconstruction, which can shorten the surgical duration and improve the accuracy and safety of the operation.

  9. Water infiltration and intermittent flow in rough-walled fractures

    SciTech Connect

    Su, Grace

    1995-05-01

    Flow visualization experiments were conducted in transparent replicas of natural rough-walled fractures. The fracture was inclined to observe the interplay between capillary and gravity forces. Water was introduced into the fracture by a capillary siphon. Preferential flow paths were observed, where intermittent flow frequently occurred. The water infiltration experiments suggest that intermittent flow in fractures appears to be the rule rather than the exception. In order to investigate the mechanism causing intermittent flow in fractures, parallel plates with different apertures were assembled using lucite and glass. A medium-coarse-fine pore structure is believed to cause the intermittency in flow. Intermittent flow was successfully produced in the parallel plate experiments using the lucite plates. After several trials, intermittent flow was also produced in the glass plates.

  10. Preseptal transconjunctival approach to the orbital floor fractures. Surgical technique.

    PubMed

    Bruneau, S; Scolozzi, P

    2015-12-01

    Orbital floor fractures may be reached through 2 types of conjunctival approaches, the preseptal one and the retroseptal one. While the retroseptal approach offers a more direct and easier route to the orbital rim and floor, it is associated with a significantly higher rate of lower lid complications compared to the preseptal approach. We will focus on the preseptal transconjunctival approach. The conjunctival incision is performed with a guarded needle-tip electrocautery or with a long-handled scalpel (blade No. 15) from the inferior extremity of the semilunar fold to the lateral canthal region. The subconjunctival plane is divided with Stevens scissors medially and laterally. This plane, located between the preseptal cranial conjunctival flap covered by the orbital septum and the caudal conjunctival flap covered by the orbicular muscle's fascia, is opened with the scissors toward the inferior orbital rim. The periosteum over the inferior orbital rim is incised and reflected. The subperiosteal dissection is continued toward the orbital floor. The incarcerated periorbital tissues are repositioned to expose the stable bone margins of the fracture before orbital reconstruction. The closure of the periorbita is performed with uninterrupted 5-0 Vicryl sutures. The conjunctiva is closed with a running 6-0 Maxon suture. Although technically more demanding than the retroseptal approach, the preseptal approach enables a large and safe access to the entire orbital floor by passing through an anatomical bloodless plane. This approach can also be combined with a lateral canthotomy/cantholysis and with a medial caruncular transconjunctival incision, thus providing extended exposure of the entire orbit. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  11. Orbital wall infarction in child with sickle cell disease.

    PubMed

    Janssens, C; Claeys, L; Maes, P; Boiy, T; Wojciechowski, M

    2015-12-01

    We present the case of a 17-year-old boy, known with homozygous sickle cell disease, who was admitted because of generalised pain. He developed bilateral periorbital oedema and proptosis, without pain or visual disturbances. In addition to hyperhydration, oxygen and analgesia IV antibiotics were started, to cover a possible osteomyelitis. Patients with sickle cell disease are at risk for vaso-occlusive crises, when the abnormally shaped red blood cells aggregate and block the capillaries. Such a crisis typically presents at a location with high bone marrow activity, as the vertebrae and long bones. At an early age, the bone marrow is still active at other sites, for example the orbital wall, and thus infarction can also occur there. Thus, in young persons with sickle cell disease, it is important to consider orbital wall infarction in the differential diagnosis, since the approach is different from osteomyelitis. If the disease is complicated by an orbital compression syndrome, corticosteroids or surgical intervention may be necessary to preserve the vision. In our patient, an MRI of the orbitae demonstrated periorbital oedema with bone anomalies in the orbital and frontal bones, confirming orbital wall infarction. Ophthalmological examination revealed no signs of pressure on the nervus opticus. The patient recovered gradually with conservative treatment.

  12. Technical concept of patient-specific, ultrahigh molecular weight polyethylene orbital wall implant.

    PubMed

    Kozakiewicz, Marcin; Elgalal, Marcin; Walkowiak, Bogdan; Stefanczyk, Ludomir

    2013-06-01

    The authors have been using patient-specific implants since 2006 and are constantly looking for new reconstructive materials, in order to create precise implants for orbital reconstruction. Such materials should be biocompatible and stable in the human body, as well as easy to machine and form into complex 3D shapes. Biocompatible ultrahigh molecular weight polyethylene (UHMW-PE) has several unique properties including high impact strength and a low friction coefficient that result in self-lubricating and thus non-sticking surfaces after processing. To present the concept of a patient-specific, UHMW-PE orbital wall implant. The material used to manufacture the orbital implant was UHMW-PE converted into a solid block of medical polymer from a powder material. A delayed treatment unilateral orbital fracture case was chosen for reconstruction with patient-specific orbital wall implant. On the basis of computerized tomography, a virtual model of both orbits was prepared. The injured orbit was significantly enlarged due to dislocation of its walls. The 3D model of the facial skeleton was symmetrically divided into two parts. This resulted in two models - left and right orbit, then the uninjured orbit was superimposed onto the contralateral side. As a result two surfaces were created; the outer surface (taken from the injured orbit) was used to design the outer surface of the implant, and the inner (taken from the uninjured orbit) for the inner surface. By combining both these surfaces it was possible to determine the unique shape and thickness of the UHMW-PE implant that would allow for accurate reconstruction of the orbit. Following this, the CAD model was transferred to CAM software and a numerical code for a 5-axis milling machine was generated. The manufactured implant was sterilized in gas plasma and used to reconstruct three orbital walls. The thickness of the manufactured implant ranged from 0.2 mm to 1.5 mm and was successfully inserted via transconjunctival

  13. Computer-aided orbital wall defects treatment by individual design ultrahigh molecular weight polyethylene implants.

    PubMed

    Kozakiewicz, Marcin

    2014-06-01

    Despite of well-known advantages of high molecular weight polyethylene (Medpor, Synpore) in orbital reconstructions, the thickness of those implants significantly exceeds 0.5 mm and precise modification of thickness is limited. The aim of this study was to present the application of a self-developed method of treatment orbital wall fracture by custom implant made of ultrahigh molecular weight polyethylene (UHMW-PE). First, the test of influence of sterilization process upon implant deformation was performed (autoclaving, ethylene oxide, gas plasma, irradiation). Next, ten cases for delayed surgical treatment of orbital fracture were included into this study (7 males, 3 females). Based on CT scan and mirrored technique, a CAD model of virtual implant for repairing orbital wall was made. Then, an implant was manufactured with a computer numerical controlled milling machine from UHMW-PE block, sterilized and used during a surgical procedure. Clinically used implants had thickness from 0.2 to 4.0 mm. The best method of sterilization is ethylene oxide process, and the worst is autoclaving. In this series of delayed surgical cases, functional results of orbital surgery are worse than in simpler, early treated cases, but long-term subsidence of diplopia is noticeable [10% poor results]. The results of the treatment depend on the initial level of diplopia where severe initial diplopia to be corrected requires thicker implants (p < 0.01). It also leads to longer surgical procedures (p < 0.01), but prolongation of the surgery had no negative influence upon results of any investigated follow-up examinations. Obviously, the orbital destruction intensity is related to injury-evoked initial diplopia but it also influences whole results of treatment up to 12 months post-op. Interesting result is presented by the relation of maximal implant thickness to 12-month diplopia evaluation. Thicker implants used result in lower residual diplopia (p < 0.05). This is important because of

  14. Boiling radial flow in fractures of varying wall porosity

    SciTech Connect

    Barnitt, Robb Allan

    2000-06-01

    The focus of this report is the coupling of conductive heat transfer and boiling convective heat transfer, with boiling flow in a rock fracture. A series of experiments observed differences in boiling regimes and behavior, and attempted to quantify a boiling convection coefficient. The experimental study involved boiling radial flow in a simulated fracture, bounded by a variety of materials. Nonporous and impermeable aluminum, highly porous and permeable Berea sandstone, and minimally porous and permeable graywacke from The Geysers geothermal field. On nonporous surfaces, the heat flux was not strongly coupled to injection rate into the fracture. However, for porous surfaces, heat flux, and associated values of excess temperature and a boiling convection coefficient exhibited variation with injection rate. Nucleation was shown to occur not upon the visible surface of porous materials, but a distance below the surface, within the matrix. The depth of boiling was a function of injection rate, thermal power supplied to the fracture, and the porosity and permeability of the rock. Although matrix boiling beyond fracture wall may apply only to a finite radius around the point of injection, higher values of heat flux and a boiling convection coefficient may be realized with boiling in a porous, rather than nonporous surface bounded fracture.

  15. Outcomes of Orbital Blow-Out Fracture Repair Performed Beyond 6 Weeks After Injury.

    PubMed

    Scawn, Richard L; Lim, Lee Hooi; Whipple, Katherine M; Dolmetsch, Angela; Priel, Ayelet; Korn, Bobby; Kikkawa, Don O

    2016-01-01

    Blow-out fractures cause expansion of the bony orbital walls and prolapse of orbital contents in the sinuses. This can result in diplopia, enophthalmos, and hypoglobus. Early surgical repair has been previously recommended, however, recent reports show that delayed surgery can also be effective. In this study, the clinical and functional outcome of patients with delayed presentation and blow-out fracture repair beyond 6 weeks after injury are described. This is a noncomparative retrospective study. Medical records of adult patients with late orbital floor fracture repair performed by 4 surgeons from April 2008 to January 2014 at 3 tertiary referral centers were reviewed. All repairs were performed more than 6 weeks from the time of injury. Patients with prior orbital fracture repair surgery were excluded. Twenty patients were included in the study. The duration from time of injury to surgery ranged from 7 weeks to 21 years with a mean of 19 months. Follow up ranged from 6 weeks to 56 months (mean 8 months). Mean age was 48 years (range, 25-80). Male to female ratio was 11:9. Surgery was performed on 10 right eyes and 10 left eyes. CT imaging demonstrated 10 patients had isolated floor fractures, while the remaining 10 patients had combined floor and medial wall fractures. Four patients also had associated facial fractures that did not require surgery. Indications for surgery included enophthalmos of 2 mm or more (18 of 20) and/or significant diplopia within 30° of primary gaze (6 of 20). Mean pre- and postoperative enophthalmos was 2.4 ± 0.9 mm and 0.3 ± 0.2 mm, respectively, corresponding to a mean reduction in enophthalmos of 2.1 ± 1.2 mm (range, 1-5 mm). Four of 7 patients with hypoglobus ranging from 1.5 mm to 8 mm preoperatively had complete resolution postoperatively, the remaining 3 patients showed reduced hypoglobus. Of the 12 patients that had diplopia preoperatively in any position of gaze, 6 patients had complete resolution

  16. Cell wall swelling, fracture mode, and the mechanical properties of cherry fruit skins are closely related.

    PubMed

    Brüggenwirth, Martin; Knoche, Moritz

    2017-04-01

    Cell wall swelling, fracture mode (along the middle lamellae vs. across cell walls), stiffness, and pressure at fracture of the sweet cherry fruit skin are closely related. Skin cracking is a common phenomenon in many crops bearing fleshy fruit. The objectives were to investigate relationships between the mode of fracture, the extent of cell wall swelling, and the mechanical properties of the fruit skin using sweet cherry (Prunus avium) as a model. Cracking was induced by incubating whole fruit in deionised water or by fracturing exocarp segments (ESs) in biaxial tensile tests. The fracture mode of epidermal cells was investigated by light microscopy. In biaxial tensile tests, the anticlinal cell walls of the ES fractured predominantly across the cell walls (rather than along) and showed no cell wall swelling. In contrast, fruit incubated in water fractured predominantly along the anticlinal epidermal cell walls and the cell walls were swollen. Swelling of cell walls also occurred when ESs were incubated in malic acid, in hypertonic solutions of sucrose, or in water. Compared to the untreated controls, these treatments resulted in more frequent fractures along the cell walls, lower pressures at fracture (p fracture), and lower moduli of elasticity (E, i.e., less stiff). Conversely, compared to the untreated controls, incubating the ES in CaCl2 and in high concentrations of ethanol resulted in thinner cell walls, in less frequent fractures along the cell walls, higher E and p fracture. Our study demonstrates that fracture mode, stiffness, and pressure at fracture are closely related to cell wall swelling. A number of other factors, including cultivar, ripening stage, turgor, CaCl2, and malic acid, exert their effects only indirectly, i.e., by affecting cell wall swelling.

  17. Orbital fracture and eyeball rupture caused by golf-club injury.

    PubMed

    Hwang, Kun; Kim, Joo Ho

    2014-05-01

    We report a case of an orbital fracture and an eyeball rupture caused by a golf-club injury. A 75-year-old man was struck in his right eye by a golf club while watching behind his son swinging a hybrid-type golf club at his home. A 70-mm muscle-depth laceration was present in the infraorbital area with active bleeding. Computed tomographic imaging of the face revealed a rupture of the right eyeball; fractures in the superior, medial, lateral, and inferior wall of the right orbit; a fracture in the right zygomaticofrontal junction; and a small amount of pneumocephalus in the parafalx region. Under general anesthesia, evisceration of the right eyeball was performed. Not only golfers but also people just watching or passing by can be injured by an errantly struck golf ball or swung golf club. Elderly people as well as children should be instructed in technique and safety and also be supervised when playing golf. Also, the public should be educated about the risk of eye injuries and the benefits of wearing a protective eyewear.

  18. Fracture resistance of zigzag single walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Lu, Qiang; Bhattacharya, Baidurya

    2006-03-01

    Carbon nanotubes (CNTs) are known to possess extraordinary strength, stiffness and ductility properties. Their fracture resistance is an important issue from the perspective of durability and reliability of CNT-based materials and devices. According to existing studies, brittle fracture is one of the important failure modes of single-walled carbon nanotube (SWNT) failure due to mechanical loading. However, based on the authors' knowledge, the fracture resistance of CNTs has not been quantified so far. In this paper, the fracture resistance of zigzag SWNTs with preexisting defects is calculated using fracture mechanics concepts based on atomistic simulations. The interatomic forces are modelled with a modified Morse potential; the Anderson thermostat is used for temperature control. The problem of unstable crack growth at finite temperature, presumably caused by the lattice trapping effect, is circumvented by computing the strain energy release rate through a series of displacement-controlled tensile loading of SWNTs (applied through moving the outermost layer of atoms at one end at constant strain rate of 9.4 × 10-4 ps-1) with pre-existing crack-like defects of various lengths. The strain energy release rate, G, is computed for (17, 0), (28, 0) and (35, 0) SWNTs (each with aspect ratio 4) with pre-existing cracks up to 29.5 Å long. The fracture resistance, Gc, is determined as a function of crack length for each tube at three different temperatures (1, 300 and 500 K). A significant dependence of Gc on crack length is observed, reminiscent of the rising R curve behaviour of metals at the macroscale: for the zigzag nanotubes Gc increases with crack length at small length, and tends to reach a constant value if the tube diameter is large enough. We suspect that the lattice trapping effect plays the role of crack tip plasticity at the atomic scale. For example, at 300 K, Gc for the (35, 0) tube with aspect ratio 4 converges to 6 J m-2 as the crack length exceeds 20

  19. Smooth nylon foil (SupraFOIL) orbital implants in orbital fractures: a case series of 181 patients.

    PubMed

    Park, D J John; Garibaldi, Daniel C; Iliff, Nicholas T; Grant, Michael P; Merbs, Shannath L

    2008-01-01

    The SupraFOIL smooth nylon foil implant is a polyamide sheet available in varying thicknesses that has been used in orbital reconstruction following trauma. The authors report their experience with smooth nylon foil implants in the repair of orbital fractures. A retrospective chart review of patients having undergone repair of orbital fractures between January 1, 1995 and December 31, 2003 was conducted. The Wilcoxon test was used to compare cases with complications and those with no complications. Of 282 orbits that underwent fracture repair with alloplastic material, 87 were excluded because non-nylon foil implants were used alone or in combination with nylon foil to repair the orbital fracture. An additional 14 fractures were excluded because of insufficient clinical data or lack of follow-up, for a total of 181 orbits that underwent orbital fracture repair with only nylon foil. A transconjunctival approach was used in 98% cases, and all 181 implants were fixated with at least 1 titanium screw. Average follow-up was 362.8 days. The overall complication rate was 1.7%. One patient had an acute postoperative orbital hemorrhage (0.6% acute complication rate). Two patients had late orbital infections, 683 days and 984 days following repair (1.1% late complication rate). The authors found the smooth nylon foil implant to be safe and effective in orbital fracture repair. The lower rate of complications the authors observed compared with previously reported series may be related to implant fixation. A titanium screw secured just posterior to the orbital rim may decrease long-term complications by providing more stability than implants left without fixation.

  20. Solute transport in a synthetic fracture with one porous wall: fracture-matrix interaction

    NASA Astrophysics Data System (ADS)

    Michel, L.; Meheust, Y.; Caudal, J.; de Bremond D'Ars, J.; de Dreuzy, J.; Davy, P.

    2007-12-01

    Contaminant transport in heterogeneous fractured aquifers occurs mostly through the networks of intersecting fractures. The physical mechanisms of solute transport in a single fracture with impermeable walls are well identified (Dronfield and Silliman 1993; Roux, Plouraboué et al. 1998; Keller, Roberts et al. 1999; Detwiler and Rajaram 2000): advection, Taylor-Aris dispersion, roughness dispersion, aperture-variation dispersion and molecular diffusion. However, when the permeability of the surrounding rock matrix cannot be neglected, there is, to our knowledge, no fundamental description of the mass transfert coefficient between the region of high permeability (the fracture) and that of low permeability (the surrounding matrix). We address here solute transport through a synthetic fracture with a porous wall. We present an analog experimental model setup in which we can focus on specific dispersion mechanisms, neglecting molecular diffusion, in order to extract descriptive laws that will be integrated in future numerical models. The planar horizontal fracture is 1 m long, 5 cm wide and its mean aperture is 5 mm. It is bounded by either two smooth parallel Plexiglass plates (impermeable walls configuration), or by one such plate and a porous medium consisting of 1 mm glass beads ("semi-permeable" configuration). A permanent laminar water flow is forced through the fracture at controlled mean velocity (~ 1mm/s), and a dye (patent blue) injection system simulates a point source of contaminant along the center plane of the fracture. The tracer plume is tracked using a visualization system based on (i) lasers illuminating a series of vertical linear optical sensor arrays, and (ii) 4 cameras positioned side by side and providing a composite image of the fracture viewed from the side. The two measurement systems yield consistent quantitative temporal descriptions of the tracer concentration, integrated over the fracture width and at several positions along the fracture

  1. Orbital blow-out fractures: correlation of preoperative computed tomography and postoperative ocular motility.

    PubMed Central

    Harris, G J; Garcia, G H; Logani, S C; Murphy, M L; Sheth, B P; Seth, A K

    1998-01-01

    BACKGROUND/PURPOSE: Although the management of orbital blow-out fractures was controversial for many years, refined imaging with computed tomography (CT) helped to narrow the poles of the debate. Many orbital surgeons currently recommend repair if fracture size portends late enophthalmos, or if diplopia has not substantially resolved within 2 weeks of the injury. While volumetric considerations have been generally well-served by this approach, ocular motility outcomes have been less than ideal. In one series, almost 50% of patients had residual diplopia 6 months after surgery. A fine network of fibrous septa that functionally unites the periosteum of the orbital floor, the inferior fibrofatty tissues, and the sheaths of the inferior rectus and oblique muscles was demonstrated by Koornneef. Entrapment between bone fragments of any of the components of this anatomic unit can limit ocular motility. Based on the pathogenesis of blow-out fractures, in which the fibrofatty-muscular complex is driven to varying degrees between bone fragments, some measure of soft tissue damage might be anticipated. Subsequent intrinsic fibrosis and contraction can tether globe movement, despite complete reduction of herniated orbital tissue from the fracture site. We postulated that the extent of this soft tissue damage might be estimated from preoperative imaging studies. METHODS: Study criteria included: retrievable coronal CT scans; fractures of the orbital floor without rim involvement, with or without extension into the medial wall; preoperative diplopia; surgical repair by a single surgeon; complete release of entrapped tissues; and postoperative ocular motility outcomes documented with binocular visual fields (BVFs). Thirty patients met all criteria. The CT scans and BVFs were assessed by different examiners among the authors. Fractures were classified into 3 general categories and 2 subtypes to reflect the severity of soft tissue damage within each category. "Trap-door" injuries

  2. The Acetabular Fracture Prognostic Nomogram: Does it Work for Fractures of the Posterior Wall?

    PubMed

    Moed, Berton R; McMahon, Megan J; Armbrecht, Eric S

    2016-04-01

    A recently proposed nomogram is an attempt to define the subset of acetabular fractures at risk for primary total hip arthroplasty (THA) within 2 years of open reduction and internal fixation (ORIF). Our objectives were to determine whether this nomogram provides information adequate to reliably (1) prognosticate outcome within 2 years after ORIF or (2) identify optimal initial treatment choice (THA vs. ORIF) for patients with a posterior wall fracture. Retrospective case series. University level 1 Trauma Center. From a database of consecutive posterior wall fractures treated by ORIF, 103 patients were identified for analysis: 6 with an unsatisfactory result at less than 2 years and 97 followed 2-14 years. Calculation of percent risk of requiring THA within 2 years using the nomogram. Comparison of this percent risk to the actual clinical outcome within 2 years after ORIF, measured in 2 ways: (1) THA performed (5 patients) and (2) overall unsatisfactory hip function determined by the modified Merle d'Aubigné score (9 patients total: the 5 with THA plus 4 additional without THA but having unsatisfactory hip function). The calculated percent risk ranged widely, with much overlap among patients having satisfactory or unsatisfactory results of ORIF. Statistical analysis did not yield a clinically useful positive predictive value: 0.25 [95% confidence interval (CI), 0.08-0.53] for THA and 0.44 (95% CI, 0.21-0.69) for an overall unsatisfactory clinical result. The acetabular fracture prognostic nomogram in its current form does not provide sufficient information to prognosticate outcome after ORIF or to determine appropriate surgical management for posterior wall fractures. Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

  3. Footprints of the globe: a practical look at the mechanism of orbital blowout fractures, with a revisit to the work of Raymond Pfeiffer.

    PubMed

    Erling, B F; Iliff, N; Robertson, B; Manson, P N

    1999-04-01

    Multiple mechanisms of orbital blowout fractures have been proposed since the fracture was described at the beginning of this century. The original theory of direct globe-to-wall contact was abandoned long ago for the more contemporary hydraulic and bone conduction theories. Although the more widely accepted theories play an obvious role in fracture generation and its associated complications, it is our contention that direct globe-to-wall contact is an important and largely unrecognized mechanism in orbital blowout fracture production. By means of a critical review of the historical literature and an analysis of patient computed tomography scans, support is presented for the original theory first proposed by Raymond Pfeiffer in 1943.

  4. Secondary correction of posttraumatic orbital wall adhesions by membranes laminated with amniotic membrane.

    PubMed

    Rommel, Niklas; Rohleder, Nils H; Gabriel, Christian; Hennerbichler, Simone; Bauer, Florian; Mücke, Thomas; Kolk, Andreas; Loeffelbein, Denys J; Wolff, Klaus D; Kesting, Marco R

    2013-12-01

    The objective of the study was to find out if human amniotic membrane could be used for corrective surgery after trauma to the orbital wall. Because of its proposed antiadhesive qualities, it seemed to be potentially suitable. We studied 8 men (mean age 37 (range 19-74) years) who had deficient ocular movement after fractures of the orbital floor. Five of them had already been operated on. Inclusion criteria were trauma dating back more than 4 months and a soft tissue stricture in the orbital floor diagnosed by magnetic resonance imaging. Patients were treated secondarily with lysis of adhesions and insertion of allogeneic human amniotic membrane laminated on to polyglactin 910/polydioxanone foil, which functioned as the carrier material. Patients were followed up for 3 months, by which time disorders of motility of the ocular bulb had disappeared completely in 5. Two patients had improved motility and a reduction in both their subjective and objective symptoms. One patient had no improvement. The considerable reduction in adhesions and scarring after insertion of the membrane confirms previous assumptions, according to which the epithelial side of the human amniotic membrane has an antiadhesive effect because of its smooth surface.

  5. Arthroscopic Reduction and Transportal Screw Fixation of Acetabular Posterior Wall Fracture: Technical Note

    PubMed Central

    Park, Jin young; Kim, Che Keun; Huh, Soon Ho; Kim, Se Jin; Jung, Bo Hyun

    2016-01-01

    Acetabular fractures can be treated with variable method. In this study, acetabular posterior wall fracture was treated with arthroscopic reduction and fixation using cannulated screw. The patient recovered immediately and had a satisfactory outcome. In some case of acetabular fracture could be good indication with additional advantages of joint debridement and loose body removal. So, we report our case with technical note. PMID:27536654

  6. Use of copolymer polylactic and polyglycolic acid resorbable plates in repair of orbital floor fractures.

    PubMed

    Lin, Jonathan; German, Michael; Wong, Brian

    2014-10-01

    The fractures of the orbital floor are common after craniofacial trauma. Repair with resorbable plates is a viable reconstructive option; however, there are few reports in the literature. This study describes our experience using copolymer polylactic and polyglycolic acid (PLLA/PGA) orbital reconstruction plates (LactoSorb, Lorenz Surgical, Jacksonville, FL) in 29 cases of the orbital floor fracture repair. We conducted a retrospective review of 29 orbital floor fractures at a single institution repaired through transconjunctival, preseptal dissection using PLLA/PGA plates fashioned to repair the orbital floor defect. Associated fractures included zygomaticomaxillary, LeFort, and nasoethmoid fractures. There were six patients with complications. Four patients had transient diplopia with complete resolution of symptoms within 1 year. One patient had diplopia postoperatively, but was later lost to follow-up. Two patients have had persistent enophthalmos since 1 year. In each of these cases, the floor fracture was coincident with significant panfacial or neurotrauma. We did not encounter any adverse inflammatory reactions to the implant material itself. The study concluded that orbital floor fracture repair with resorbable plates is safe, relatively easy to perform, and in the majority of cases was effective without complications. In the presence of severe orbital trauma, more rigid implant materials may be appropriate.

  7. The effects of airbags on orbital fracture patterns in frontal automobile crashes.

    PubMed

    Duma, Stefan M; Jernigan, M Virginia

    2003-03-01

    To investigate orbital fractures that occurred in frontal automobile crashes and to determine the effects of frontal airbags on injury incidence and severity. The National Automotive Sampling System database files from 1993 to 2000 were examined. Frontal crashes were selected that included drivers and front-seat passengers only and excluded ejected occupants and rollover crashes. Orbital fractures could be closed, open, displaced, or any combination of these and were identified by using the Abbreviated Injury Scale codes. The analysis included 12,429,580 front-seat occupants from 25,464 cases. Of all occupants who were exposed to an airbag deployment, 0.09% sustained an orbital fracture. In contrast, occupants who were not exposed to an airbag deployment were more than twice as likely to sustain an orbital fracture (0.22%). In addition to reduction in incidence, airbags were also shown to decrease the severity of orbital fractures that occupants sustained. Occupants exposed to airbag deployment mostly sustained closed, less severe fractures (61.9%), whereas occupants not exposed to airbag deployment sustained the majority as more severe, open, displaced, or comminuted fractures (61.3%). This article presents the most comprehensive study of orbital fractures in automobile crashes to date. It is shown that both the incidence and the overall severity of orbital fractures decreases considerably with exposure to airbag deployment. This is accomplished because the airbag minimizes occupant contact with the windshield and steering wheel, which are the two leading sources of orbital fractures for occupants not exposed to airbag deployment.

  8. Usefulness of a Transconjunctival Approach in the Reconstruction of the Medial Blow-Out Wall Fracture.

    PubMed

    Lee, Chi An; Sun, Hook; Yun, Ji Young

    2017-06-01

    A transcaruncular approach is typically used for reconstructions of medial wall fractures. However, others reported that a transconjunctival approach was conducive for securing an adequate surgical field of view. In this study, we aimed to examine the extent of repair of medial wall fracture via a transconjunctival approach. We retrospectively reviewed the medical records of 50 patients diagnosed as having medial wall fracture via preoperative computed tomography and who underwent surgery between March 2011 and February 2014. The fracture location was defined by dividing each of the anterior-posterior and superior-inferior distances into three compartments. A transcaruncular approach was used in 7 patients, while the transconjunctival approach was performed in the remaining 43 patients. The transconjunctival approach enabled a relatively broad range of repair that partially included the front and back of the medial wall, and was successful in 86% of the entire study population. It is known that more than 50% of total cases of the medial wall fracture occur mainly in the middle-middle portion, a majority of which can be reconstructed via a transconjunctival approach. We used a transconjunctival approach in identifying the location of the fracture on image scans except for cases including the fracture of the superior portion in patients with medial wall fracture. If it is possible to identify the location of the fracture, a transconjunctival approach would be an useful method for the reconstruction in that it causes no damages to the lacrimal system and is useful in confirming the overall status of the floor.

  9. Hydraulic fracturing model featuring initiation beyond the wellbore wall for directional well in coal bed

    NASA Astrophysics Data System (ADS)

    Li, Yuwei; Jia, Dan; Wang, Meng; Liu, Jia; Fu, Chunkai; Yang, Xinliang; Ai, Chi

    2016-08-01

    In developing internal fracture systems in coal beds, the initiation mechanism differs greatly from that of conventional ones and initiations may be produced beyond the wellbore wall. This paper describes the features of the internal structure of coal beds and RFPA2D simulation is used to attest the possible occurrence of initiation beyond the wellbore wall in coal bed hydraulic fracturing. Using the theory of elasticity and fracture mechanics, we analyse the stress distribution in the vicinal coal rock. Then by taking into consideration the effects of the spatial relationship between coal bed cleats and the wellbore, we establish a model for calculating both tensile and shear initiation pressure that occur along cleats beyond the wellbore wall. The simulation in this paper indicates that for shear initiations that happen along coal cleats, the pressure required to initiate fracture for cleats beyond the wellbore wall is evidently lower than that on the wellbore wall, thus it is easier to initiate shear fractures for cleats beyond the wellbore wall. For tensile failure, the pressure required to initiate tensile fracture for cleats beyond the wellbore wall is obviously higher than that for cleats at the wellbore wall, thus it is easier to initiate tensile fractures for cleats at the wellbore wall. On the one hand, this paper has proved the possible occurrence of initiations beyond the wellbore wall and has changed the current assumption that hydraulic fractures can only occur at the wellbore wall. On the other hand, the established theoretical model provides a new approach to calculating the initiation pressure in hydraulic fracturing.

  10. Sunken Eye Induced by Superior Orbital Wall Defect After Craniofacial Surgery

    PubMed Central

    Joo, Sung-Pil; Kim, Sung-Hyun; Park, Hong-Ju; Jung, Seunggon; Han, Jeong Joon; Kim, Tae-Sun

    2016-01-01

    Abstract Enophthalmos after a ventriculo-peritoneal (V-P) shunt placement is very rare. Previous defects of the orbital wall with intracranial hypotension can cause enophthalmos after V-P shunting. The authors present 2 patients of enophthalmos with orbital wall defects resulting from anterior clinoidectomy that was performed during previous aneurysmal surgery. Both patients received a V-P shunt for hydrocephalus after subarachnoid hemorrhage. Although the hydrocephalus was improved by V-P shunts in both patients, sunken eyes were observed. The patients received reconstructive surgery of the superior orbital wall using titanium mesh and recovered after surgery without any neurological deficits. Here, the authors present 2 patients of enophthalmos with orbital wall defects treated by orbital wall reconstruction. PMID:27483101

  11. Sunken Eye Induced by Superior Orbital Wall Defect After Craniofacial Surgery.

    PubMed

    Joo, Sung-Pil; Kim, Sung-Hyun; Park, Hong-Ju; Jung, Seunggon; Han, Jeong Joon; Kim, Tae-Sun

    2016-10-01

    Enophthalmos after a ventriculo-peritoneal (V-P) shunt placement is very rare. Previous defects of the orbital wall with intracranial hypotension can cause enophthalmos after V-P shunting. The authors present 2 patients of enophthalmos with orbital wall defects resulting from anterior clinoidectomy that was performed during previous aneurysmal surgery. Both patients received a V-P shunt for hydrocephalus after subarachnoid hemorrhage. Although the hydrocephalus was improved by V-P shunts in both patients, sunken eyes were observed. The patients received reconstructive surgery of the superior orbital wall using titanium mesh and recovered after surgery without any neurological deficits. Here, the authors present 2 patients of enophthalmos with orbital wall defects treated by orbital wall reconstruction.

  12. BMP implant associated with platelet-rich plasma in orbit fracture repair.

    PubMed

    Ferraz, Fabio Henrique; Schellini, Silvana Artioli; Schellini, Ricardo Campos; Pellizon, Claudia Helena; Hirai, Flavio Eduardo; Padovani, Carlos Roberto

    2008-03-01

    To evaluate a bone morphogenetic protein (BMP) implant with and without platelet-rich plasma (PRP), which is supposed to accelerate fracture consolidation in the orbit fracture treatment. Thirty-six white rabbits were subjected to orbital fracture and treated in three groups: BMP implant fracture repair (G1), BMP plus PRP implant fracture repair (G2), and fracture and spontaneous repair (G3). The animals were sacrificed at 7, 30, 90, and 180 days after surgery. A radiology evaluation was carried out on the 7th day after the fracture and at the sacrifice moments. After the animals' death, the orbital content material was removed and prepared for morphological and morphometric analysis. Radiology suggested intramembranous and progressive cavitation and ossification without a reduction in implant size and with signs of calcium deposition; these events were confirmed by histological analysis, which showed a lymphomononuclear inflammatory reaction in G1 and G2, more intense 7 days after surgery and reducing after 30 days. Associating PRP with BMP did not accelerate bone induction. BMP implant promotes bone induction, integration at fracture site, scarce inflammatory reaction, and may be a good alternative in orbit fracture reconstruction. The addition of PRP to the BMP plate did not accelerate the resolution, and its use is not necessary.

  13. Treatment of Orbital Roof Blow-Up Fracture Using a Superior Blepharoplasty Incision.

    PubMed

    Matsuzaki, Kyoichi; Enomoto, Sayaka; Aoki, Tomoko

    2015-06-01

    In orbital roof blow-up fractures, reduction can be achieved easily using an approach from the anterior cranial fossa but the procedure is highly invasive. In contrast, an orbital approach using a superior blepharoplasty incision is minimally invasive. However, if bone fragments are adhered to the dura mater, there is a risk of dura mater injury when fragments are moved for reduction. In blow-in fractures, reduction is performed by pushing the bone fragments against the anterior cranial fossa. In contrast, the procedure is difficult for blow-up fractures because bone fragments must be pulled out into the orbit through the anterior cranial fossa. Orbital blow-up fractures are often associated with intracranial injuries and frequently treated by an approach from the anterior cranial fossa. There has not yet been a report that discusses whether reduction of bone fragments should be performed in blow-up fracture without intracranial injury. In this report, we describe two cases of orbital roof blow-up fracture that did not require treatment for intracranial injury and that were treated using an orbital approach. The treatment involved only the release of orbital fat entrapped between bone fragments and did not involve reduction. The treatment outcomes were good in both cases.

  14. A Protocol to Reduce Interobserver Variability in the Computed Tomography Measurement of Orbital Floor Fractures.

    PubMed

    Ang, Chuan Han; Low, Jin Rong; Shen, Jia Yi; Cai, Elijah Zheng Yang; Hing, Eileen Chor Hoong; Chan, Yiong Huak; Sundar, Gangadhara; Lim, Thiam Chye

    2015-12-01

    Orbital fracture detection and size determination from computed tomography (CT) scans affect the decision to operate, the type of surgical implant used, and postoperative outcomes. However, the lack of standardization of radiological signs often leads to the false-positive detection of orbital fractures, while nonstandardized landmarks lead to inaccurate defect measurements. We aim to design a novel protocol for CT measurement of orbital floor fractures and evaluate the interobserver variability on CT scan images. Qualitative aspects of this protocol include identifying direct and indirect signs of orbital fractures on CT scan images. Quantitative aspects of this protocol include measuring the surface area of pure orbital floor fractures using computer software. In this study, 15 independent observers without clinical experience in orbital fracture detection and measurement measured the orbital floor fractures of three randomly selected patients following the protocol. The time required for each measurement was recorded. The intraclass correlation coefficient of the surface area measurements is 0.999 (0.997-1.000) with p-value < 0.001. This suggests that any observer measuring the surface area will obtain a similar estimation of the fractured surface area. The maximum error limit was 0.901 cm(2) which is less than the margin of error of 1 cm(2) in mesh trimming for orbital reconstruction. The average duration required for each measurement was 3 minutes 19 seconds (ranging from 1 minute 35 seconds to 5 minutes). Measurements performed with our novel protocol resulted in minimal interobserver variability. This protocol is effective and generated reproducible results, is easy to teach and utilize, and its findings can be interpreted easily.

  15. "Roller coaster maneuver via lateral orbital approach" for reduction of isolated zygomatic arch fractures.

    PubMed

    Pilanci, Ozgur; Basaran, Karaca; Datli, Asli; Kuvat, Samet Vasfi

    2013-11-01

    Numerous techniques have been reported for the reduction of zygomatic arch fractures. In this article, we aimed to describe a technique we named as "roller coaster maneuver via lateral orbital approach" to closed reduction of the isolated-type zygomatic arch fractures. Surgical outcomes of 14 patients treated with this method were outlined.

  16. Tomographic index as auxiliary criteria for surgery indication in fracture dislocation of acetabulum posterior wall

    PubMed Central

    2012-01-01

    There are situations which the tomographic exam is done on the affected hip or situations where the contralateral hip presents abnormalities that make it impossible to compare. In this study we aimed to evaluate a tomographic index that does not require comparison between the both hips. Twenty two patients with unilateral acetabular fracture dislocation with fracture of posterior wall were studied. We established the relationship between the remaining posterior wall and the femoral head diameter (head/wall index-H/W index). We evaluated 45 two-dimensional computed tomography scan in normal hips and established the H/W index. In 45 normal hips we simulated a posterior wall fracture with involvement of 25% and 30% of the posterior wall and calculated the H/W index. We divided into five groups with five different H/W index (fractured group with non surgical treatment; fractured group; normal group; normal group with simulated fracture of 25% and; 30% of the posterior wall). 2.4 was the lowest limit of confidence interval of the group with 25% of the posterior wall fracture. When we analyzed the confidence interval of the 30% fracture group the upper limit of the confidence interval was 2.7, close to the lower limit of the surgical group that was 2.9. Thus, we suggest the 2.4 the H/W index limit as an auxiliary criteria to indicate whether or not to operate. H/W index is helpful to decide whether or not surgery indication in the fracture dislocation of the posterior wall of the acetabulum. PMID:22715811

  17. Orbital fractures and ocular injury: is a postoperative ophthalmology examination necessary?

    PubMed

    Peacock, Zachary S; Boulos, Toufic; Miller, John B; Gardiner, Matthew F; Chuang, Sung-Kiang; Troulis, Maria J

    2014-08-01

    To determine whether formal ophthalmology evaluation is necessary after operative repair of orbital fractures and the association of an ocular injury to the severity of facial injury. This was a retrospective cohort study of patients with orbital fractures undergoing operative repair from 2005 to 2013. Subjects were included if they had undergone reconstruction of orbital floor fractures and had data from pre- and postoperative examinations by the oral and maxillofacial surgery and ophthalmology services available. The predictor variables included the service performing the ocular examination (oral and maxillofacial surgery or ophthalmology) and the number of fractures present. The outcome variables were the presence of pre- and postoperative ocular injuries. Logistic regression models were used to determine the relationship of the fracture number to ocular injury. A total of 28 subjects had undergone repair of orbital fractures with preoperative and postoperative examinations performed by both services. Preoperative ocular injuries were found in 17 of the 28 subjects. Those detected by oral and maxillofacial surgeons were limited to changes in visual acuity, pupillary response, and extraocular muscle dysfunction in 11 subjects. Two subjects had new postoperative ocular findings that were considered minor and did not alter management. An increasing number of facial fractures was associated with an increased risk of ocular trauma. Those with 3 or more fractures had an odds ratio of 14.625 (95% confidence interval, 2.191 to 97.612, P = .006) for the presence of ocular injury. Operative repair of orbital fractures did not lead to new ocular injuries that would change the management. Thus, those without preoperative ocular injuries will not require a formal postoperative ophthalmology examination. However, the subjects with more fractures had an increased likelihood of ocular injuries. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published

  18. Successful application of endoscopic modified medial maxillectomy to orbital floor trapdoor fracture in a pediatric patient.

    PubMed

    Matsuda, Yasunori; Sakaida, Hiroshi; Kobayashi, Masayoshi; Takeuchi, Kazuhiko

    2016-10-01

    Although surgical treatment of orbital floor fractures can be performed by many different approaches, the application of endoscopic modified medial maxillectomy (EMMM) for this condition has rarely been described in the literature. We report on a case of a 7-year-old boy with a trapdoor orbital floor fracture successfully treated with the application of EMMM. The patient suffered trauma to the right orbit floor and the inferior rectus was entrapped at the orbital floor. Initially, surgical repair via endoscopic endonasal approach was attempted. However, we were unable to adequately access the orbital floor through the maxillary ostium. Therefore, an alternative route of access to the orbital floor was established by EMMM. With sufficient visualization and operating space, the involved orbital content was completely released from the entrapment site and reduced into the orbit. To facilitate wound healing, the orbital floor was supported with a water-inflated urethral balloon catheter for 8 days. At follow-up 8 months later, there was no gaze restriction or complications associated with the EMMM. This case illustrates the efficacy and safety of EMMM in endoscopic endonasal repair of orbital floor fracture, particularly for cases with a narrow nasal cavity such as in pediatric patients.

  19. Modeling of flow and mixing in 3D rough-walled rock fracture intersections

    NASA Astrophysics Data System (ADS)

    Zou, Liangchao; Jing, Lanru; Cvetkovic, Vladimir

    2017-09-01

    The processes of fluid flow and solute transport through rock fractures are of primary importance in environmental engineering and geosciences. This study presented numerical modeling results of fluid flow and solute transport in a 3D rock fracture-matrix system with an orthogonal intersection of two rough-walled rock fractures. The rough-walled fracture geometry models were built from laser-scanned data of a real rock surface, for a realistic representation of natural rock fracture surface roughness. The fluid flow in the two intersected fractures and solute transport in the fracture-matrix system were simulated by solving the Navier-Stokes equations (NSE) and transport equation in the entire system. The dependence of mixing on Péclet number (Pe) and flow directionality features were analyzed. The results directly visualized important channeling flow patterns that significantly enhanced the solute mixing process at the rough-walled fracture intersection. The illustrated channeling flow and associated impacts on mixing are particularly important in the prediction of solute transport in natural fractured rocks, especially when discrete fracture network (DFN) approach is applied.

  20. Outcome of unstable isolated fractures of the posterior acetabular wall associated with hip dislocation.

    PubMed

    de Palma, L; Santucci, A; Verdenelli, A; Bugatti, M G; Meco, L; Marinelli, M

    2014-04-01

    Traumatic hip dislocation with fracture of the posterior acetabular wall is associated with high rates of residual invalidity. The records of patients who underwent surgical treatment of traumatic dislocation of the hip associated with an isolated fracture of the posterior acetabular wall from 1999 to 2009 were reviewed. There were 30 men and 12 women, who at the time of the trauma had a mean age of 42 years (range 21-65). Mean follow-up duration was 5 years (range 2-10). Pre-operative fracture evaluation was based on the classification of Judet et al. which divided this fractures into three types: type 1 is characterized by a single fracture line separating a single bone fragment from the remaining part of the posterior wall; type 2 fracture involves several fragments of the posterior wall and in type 3, a type 1 or type 2 fracture is associated with a sunk cancellous area in the acetabular wall medial to the fracture line but not affected by it, due to the shear impact of the femoral head at the time of dislocation. Clinical evaluation of the outcome was according to the criteria of Merle D'Aubigné and Postel as modified by Matta. Outcomes were divided into excellent/good and fair/poor. Since treatment was standard, data were further analyzed to assess the relative importance of age, sex, follow-up duration, sciatic nerve lesion on admission and mechanism of injury, using the Chi-square test. Full clinical recovery without sequelae or radiographic abnormalities was achieved by 10 patients, 8 with type 1 fracture and 2 with type 2 fracture. A good outcome was seen in 13 patients, 3 with type 1 fracture, 9 with type 2 fracture and 1 with type 3 fracture. Eight patients, 3 with type 2 fracture and 5 with type 3 fracture, had a fair outcome. Only follow-up ≥6 years influenced outcome significantly (p > 0.005). Our conclusions in light of our experience are that in type 1 lesions, anatomical reduction and stabilization achieve excellent outcomes, both clinical

  1. Laboratory research of hydraulic fracturing with tangential loading of borehole wall

    NASA Astrophysics Data System (ADS)

    Kurlenya, MV; Patutin, AV; Rybalkin, LA; Serdyukov, SV; Shilova, TV

    2017-02-01

    Under study is transverse fracturing of an organic glass block through secondary shearing stress applied to the borehole wall. To this effect, a system composed of a press sealer and a collet anchor manufactured in two options has been designed. It is shown than an anchor with a circular groove allows reducing breakdown pressure and enables effective transverse fracture at the borehole bottom.

  2. Endoscopic- Assisted Trephination approach for repair of Frontal Sinus posterior wall fracture in a Child.

    PubMed

    Tarrats, Luis A; Torre-León, Carlos; Almodóvar, Gustavo; Portela, Juan C

    2015-01-01

    A 9 year-old male sustained multiple maxillofacial fractures after falling from a two-store building. Frontal sinuses suffered a bilateral non-displaced linear fractures extending into the anterior and posterior walls. Magnetic resonance imaging (MRI) at this time showed a small encephalocele extending into the right frontal sinus. Operative repair was performed using an Endoscopic-Assisted Trephination approach.

  3. [Reconstruction of the orbital fracture with enophthalmos using customized titanium mesh combined with Medpor].

    PubMed

    Sun, Libo; Xiao, Jingang; Lan, Yuyan; Xiong, Yilin; Zhang, Li; Zhou, Hangyu; Zhang, Lei

    2015-06-01

    This study aims to evaluate the effect of customized titanium mesh, which was designed by mirror imaging and rapid prototyping technique, with Medpor applied for orbital fracture with enophthalmos. Orbital axial, coronal, and sagittal CT scan, and three-dimension CT examination were performed routinely in. 18 cases of orbital fracture with enophthalmos preoperatively. Based on the CT data, prosthesis model was designed by reverse engineering and rapid prototyping technique. The customized titanium mesh and Medpor were applied for orbital reconstruction and enophthalmos correction. Orbital reduction and globe projection were evaluated by postoperative CT scan and clinical follow-up visits. CT scans revealed that the customized titanium mesh with Medpor had great accuracy to reconstruct the orbital fracture and correct the enophthalmos in all patients without serious complications. The eye and facial appearance and function recovered significantly. No serious complication occurred in the operation and after operation. The customized titanium mesh, based on mirror imaging and rapid prototyping technique, can accurately reconstruct the orbital fractures with enophthalmos. The application of Medpor can effectively correct enophthalmos and eyeball mobility malformation.

  4. Usefulness of a Transconjunctival Approach in the Reconstruction of the Medial Blow-Out Wall Fracture

    PubMed Central

    Lee, Chi An; Yun, Ji Young

    2017-01-01

    Background A transcaruncular approach is typically used for reconstructions of medial wall fractures. However, others reported that a transconjunctival approach was conducive for securing an adequate surgical field of view. In this study, we aimed to examine the extent of repair of medial wall fracture via a transconjunctival approach. Methods We retrospectively reviewed the medical records of 50 patients diagnosed as having medial wall fracture via preoperative computed tomography and who underwent surgery between March 2011 and February 2014. The fracture location was defined by dividing each of the anterior-posterior and superior-inferior distances into three compartments. Results A transcaruncular approach was used in 7 patients, while the transconjunctival approach was performed in the remaining 43 patients. The transconjunctival approach enabled a relatively broad range of repair that partially included the front and back of the medial wall, and was successful in 86% of the entire study population. Conclusion It is known that more than 50% of total cases of the medial wall fracture occur mainly in the middle-middle portion, a majority of which can be reconstructed via a transconjunctival approach. We used a transconjunctival approach in identifying the location of the fracture on image scans except for cases including the fracture of the superior portion in patients with medial wall fracture. If it is possible to identify the location of the fracture, a transconjunctival approach would be an useful method for the reconstruction in that it causes no damages to the lacrimal system and is useful in confirming the overall status of the floor. PMID:28913311

  5. Can experts in acetabular fracture care determine hip stability after posterior wall fractures using plain radiographs and computed tomography?

    PubMed

    Davis, Adrian T; Moed, Berton R

    2013-10-01

    Hip stability status after a posterior wall acetabular fracture involving 20%-50% of the posterior wall is difficult to determine. However, noted experts have professed that hip stability can be accurately determined by careful review of high-quality anteroposterior and oblique plain radiographs and a computed tomography scan. The objective of this investigation was to evaluate the interobserver and intraobserver reliabilities and accuracies in determining hip stability status by fellowship-trained orthopedic traumatologists expert in acetabular fracture care using these studies. Reliability and validation study. Level 1 trauma center. Fifteen patients with isolated unilateral posterior wall (OTA 62-A1) acetabular fractures involving 20%-50% of the posterior acetabular wall and known clinical outcome had undergone dynamic stress fluoroscopy under anesthesia to determine hip stability. High-quality anteroposterior and oblique plain radiographs and axial computed tomography images of 15 fractures involving 20%-50% of the posterior acetabular wall were reviewed in random order by 4 fellowship-trained orthopedic traumatologists specializing in acetabular fracture care in 2 separate sessions. The second session occurred after a minimum 1-month washout period. Determination of hip stability status was made for each fracture at the 2 time points based on the images along with any history of dislocation of the hip at the time of injury. These determinations were compared with the findings of examination under anesthesia, which served as the gold standard. Measurement of agreement using the Kappa statistic. Although intraobserver reliability was good (0.65), interobserver reliability was poor (0.12). In addition, percent correct was only 53% (32/60) for the initial reading and only 52% (31/60) for the second. For the initial reading, sensitivity and specificity were 100% (28/28) and 13% (4/32), respectively. For the second reading, the sensitivity and specificity were 57

  6. Single-stage soft tissue reconstruction and orbital fracture repair for complex facial injuries.

    PubMed

    Wu, Peng Sen; Matoo, Reshvin; Sun, Hong; Song, Li Yuan; Kikkawa, Don O; Lu, Wei

    2017-02-01

    Orbital fractures with open periorbital wounds cause significant morbidity. Timing of debridement with fracture repair and soft tissue reconstruction is controversial. This study focuses on the efficacy of early single-stage repair in combined bony and soft tissue injuries. Retrospective review. Twenty-three patients with combined open soft tissue wounds and orbital fractures were studied for single-stage orbital reconstruction and periorbital soft tissue repair. Inclusion criteria were open soft tissue wounds with clinical and radiographic evidence of orbital fractures and repair performed within 48 h after injury. Surgical complications and reconstructive outcomes were assessed over 6 months. The main outcome measures were enophthalmos, pre- and post-CT imaging of orbits, scar evaluation, presence of diplopia, and eyelid position. Enophthalmos was corrected in 16/19 cases and improved in 3/19 cases. 3D reconstruction of CT images showed markedly improved orbital alignment with objective measurements of the optic foramen to cornea distance (mm) in reconstructed orbits relative to intact orbits of 0.66, 95% confidence interval [CI] (lower 0.33, upper 0.99) mm. The mean baseline of Stony Brook Scar Evaluation Scale was 0.6, 95%CI (0.30-0.92), and for 6 months, the mean score was 3.4, 95%CI (3.05-3.73). Residual diplopia in secondary gazes was present in two patients; one patient had ectropion. Complications included one case of local wound infection. An early single-stage repair of combined soft tissue and orbital fractures yields satisfactory functional and aesthetic outcomes. Complications are low and likely related to trauma severity. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  7. The orbit: A re-appraisal of the surgical landmarks of the medial and lateral walls.

    PubMed

    Yoon, Jisoo; Pather, Nalini

    2016-11-01

    The anterior ethmoidal foramen (AEF) and posterior ethmoidal foramina (AEF and PEF, respectively) on the medial wall and the cranio-orbital foramen (COF) on the lateral wall are used as landmarks in orbital surgeries. In surgery these foramina, the neurovascular structures they transmit and other orbital structures in close proximity need to be identified to minimise their risk of damage. Despite the clinical importance, the current understandings lack consistency in the precise location, microanatomy and morphology of the foramina. This study therefore aimed to document and analyze the microanatomy, location, and morphometric relations of the EF and COF to determine a standardized guideline to accessing the foramina. One hundred dry orbits were morphometrically analyzed, and a further six orbits were micro-dissected to determine the locations of the EF and COF. The orbital size dimensions were measured for each dry orbit and correlated with the morphometric distances. A complete morphometric and quantitative analysis showed the distances of the EF and COF to be variable, with greater variations observed in the incidence of the accessory EF and PEF distances in the medial wall, and in the presence of the COF and the accessory COF in the lateral orbital wall. Significant correlations were observed between the length of the medial orbital wall and some EF distances. This study is the first to suggest a standardized method of locating these foramina in the orbit irrespective of population and sex differences, in order to help improve clinical applications in crucial orbital surgeries. Clin. Anat. 29:998-1010, 2016. © 2016 Wiley Periodicals, Inc.

  8. Presence of a groove in the lateral wall of the human orbit.

    PubMed Central

    Santo Neto, H; Penteado, C V; de Carvalho, V C

    1984-01-01

    The presence of a groove in the lateral wall of the human orbit (Royle, 1973) was found in 45 of 100 orbits examined (45%). In 15 skulls the groove was present bilaterally. The groove probably lodges an anastomosis between the middle meningeal and infraorbital blood vessels. No reference to this groove was found in general anatomical texts. Images Fig. 1 PMID:6746401

  9. Can computed tomography predict hip stability in posterior wall acetabular fractures?

    PubMed

    Reagan, Jeffrey M; Moed, Berton R

    2011-07-01

    In a pilot study, two-dimensional (2-D) CT assessment of posterior wall fracture fragments predicted hip stability with small fracture fragments and instability for large fracture fragments. To confirm the previous findings, we determined whether there is sufficient observer consistency and accuracy to predict hip stability in posterior wall acetabular fractures for this CT assessment method and assessed its ease of clinical use. We selected 10 fractures having variable characteristics with known clinical outcome and created three study participant groups, based on level of training, for evaluation. Each observer reviewed the CT scans from the 10 fractures and applied the method in two separate sessions, the second after at least a 1-month washout period. Participants reported subjective ease in using the method, averaging 5 minutes (range, 3-11 minutes) for each assessment. Intraobserver and interobserver reliability were both greater than 0.80 regardless of the level of experience. Although sensitivity was 90%, specificity was only 61% after comparison with examination under anesthesia (EUA). Inappropriate nonoperative treatment would have occurred in 6% of cases and inappropriate operative treatment in 16%. This method for assessing hip instability is reliable, reproducible, and easy to learn and use. However, as a diagnostic tool in the clinical setting, it is useful only for fractures involving greater than 50% of the posterior wall owing to limited accuracy. For fractures less than 50%, EUA should be performed to determine hip stability.

  10. Comparative study of comminuted posterior acetabular wall fracture treated with the Acetabular Tridimensional Memory Fixation System.

    PubMed

    Zhang, Yuntong; Zhao, Xue; Tang, Yang; Zhang, Chuncai; Xu, Shuogui; Xie, Yang

    2014-04-01

    Posterior wall fractures are one of the most common acetabular fractures. However, only 30% of these fractures involve a single large fragment, and comminuted acetabular posterior wall fractures pose a particular surgical challenge. The purpose of this study was to compare outcomes between patients who received fixation for comminuted posterior wall fracture using the Acetabular Tridimensional Memory Fixation System (ATMFS) and patients who underwent fixation with conventional screws and buttress plates (Plates group). Between April 2003 and May 2007, 196 consecutive patients who sustained a comminuted posterior wall fracture of acetabulum were treated with ATMFS or conventional screws and buttress plates. Operative time, fluoroscopy time, blood loss, and any intra-operative complications were recorded. Plain AP and lateral radiographs were obtained at all visits (Matta's criteria). Modified Merle d' Aubigne-Postel score, and Mos SF-36 score were compared between groups. Fifty patients were included in the analysis with 26 in the ATMFS group and 24 in the Plates group. The mean follow-up time was 57.5 months, ranging from 31 to 69 months. All patients had fully healed fractures at the final follow-up. There was no difference in clinical outcomes or radiological evaluations between groups. Patients with comminuted posterior wall fractures of the acetabulum treated with the ATMFS or conventional screws and buttress plate techniques achieve a good surgical result. Both techniques are safe, reliable, and practical. Use of the ATMFS technique may reduce blood loss and improve rigid support to marginal bone impaction. The use ATMFS may need additional support when fractures involve the superior roof. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Sterile subperiosteal fluid collections accompanying orbital wall infarction in sickle-cell disease.

    PubMed

    Huckfeldt, Rachel M; Shah, Ankoor S

    2014-10-01

    Infarction of the orbital wall is an uncommon manifestation of sickle cell disease (SCD) that may mimic an infectious process. We report a patient with two separate orbital infarctions with different presenting symptoms involving different bones. Radiologic-guided sampling of a periosteal fluid collection in the first episode showed likely sterile inflammatory exudates. This case highlights the range of findings in orbital wall infarction in SCD as well as helpful clinical and imaging entities that may differentiate infarction from infection, allowing early diagnosis and appropriate management.

  12. Pressure wall hole size and maximum tip-to-tip crack length following orbital debris penetration

    NASA Technical Reports Server (NTRS)

    Schonberg, William P.

    1996-01-01

    The threat of damage from high speed meteoroid and orbital debris particle impacts has become a significant design consideration in the development and construction of long duration earth-orbiting spacecraft. Historically, significant amounts of resources have been devoted to developing shielding for such structures as a means of reducing the penetration potential of high speed on-orbit impacts. These efforts have typically focused on simply whether or not the inner (or 'pressure') walls of candidate multi-wall structural systems would be perforated. Only recently the nature and extent of pressure wall penetration damage have begun to be explored. This report presents the results of a study whose objective was to characterize the hole formation and cracking phenomena associated with the penetration of the multi-wall systems being considered for the International Space Station Alpha (ISSA).

  13. Infraorbital Nerve Block for Isolated Orbital Floor Fractures Repair: Review of 135 Consecutive Cases

    PubMed Central

    Spinelli, Giuseppe; Rocchetta, Davide; Carnevali, Giulia; Valente, Domenico; Conti, Marco

    2014-01-01

    Background: Orbital blowout fractures can be managed by several surgical specialties including plastic and maxillofacial surgery, otolaryngology, and ophthalmology. Recommendations for surgical fracture repair depend on a combination of clinical and imaging studies to evaluate muscle/nerve entrapment and periorbital tissue herniation. Methods: The aim of this study was to verify the applicability of regional anesthesia when repairing orbital floor fractures. A retrospective chart review was performed for isolated orbital floor fractures treated at the Department of Maxillofacial Surgery in Florence between May 2011 and July 2012. The study included 135 patients who met the inclusion criteria: 96 subjects were male (71%) and 39 were female (29%). The mean age was 45.3 years, ranging from 16 to 77 years. Results: The results revealed that isolated anterior orbital floor fractures can be safely repaired under regional and local anesthesia. Regional and local anesthesia should be combined with intravenous sedation when the fracture involves the posterior floor. The surgical outcome was comparable to the outcome achieved under general anesthesia. There was a lower rate of surgical revisions due to concealed malposition or entrapment of the inferior rectus muscle (19% vs 22%). However, this result was not statistically significant (P > 0.05). Conclusions: There are several advantages to surgically repairing isolated orbital floor fractures under regional and local anesthesia that include the following: surgeons can check the surgical outcome (enophthalmos and extrinsic ocular muscles function) intraoperatively, thereby reducing the reoperation rate; patient discomfort due to general anesthesia is eliminated; and the hospital stay is reduced, thus decreasing overall healthcare costs. PMID:25289294

  14. Modified transconjunctival lower lid approach for orbital fractures in East Asian patients: the lateral paracanthal incision revisited.

    PubMed

    Song, Jeonghoon; Lee, Gordon K; Kwon, Sung Tack; Kim, Suk Wha; Jeong, Eui Cheol

    2014-11-01

    Optimal repair of an orbital fracture requires adequate exposure into the orbit. The transconjunctival approach with lateral canthotomy is a valid option in East Asian patients, who are especially sensitive to the appearance of an external skin scar, although one must also recognize the potential complications associated with eyelid aperture mechanics. The authors report the modification of the transconjunctival approach, in which a lateral paracanthal incision is made along with division of the lateral tarsal plate but not at the lateral canthus. This was developed to overcome the complications of traditional lateral cantholysis. A retrospective chart review was performed for all patients who had received the modified transconjunctival incision. Patient demographics, injury characteristics, and surgical outcomes were evaluated. The baseline demographics of 30 patients in this study was typical of orbital fractures in the Korean population. A take-back operation was required in one case of preseptal hematoma. The mean follow-up period was 6 months, and no long-term functional complications were identified. Of the 30 total patients, 29 showed excellent aesthetic outcome. One patient did present with postoperative notch deformity but did not feel the need for a revision operation. The transconjunctival approach with a lateral paracanthal incision is an alternative approach to the orbital wall. The decoupling of the lower eyelid through the lateral portion of the tarsal plate provides excellent exposure of the orbital floor and provides a reliable and consistent landmark by which the anatomy of the eyelid can be restored. The aesthetic and functional outcomes are excellent. Therapeutic, IV.

  15. Preliminary studies of water seepage through rough-walled fractures

    SciTech Connect

    Geller, J.T.; Su, G.; Pruess, K.

    1996-07-01

    For groundwater aquifers in fractured rock, fractures play a significant role in the transport of water and contaminants through the unsaturated zone to the groundwater table. Fractures can provide preferential flow paths for infiltrating liquids that dramatically accelerate contaminant transport compared to predictions based upon spatially uniform infiltration. The actual liquid distribution during infiltration determines the contact area between the flowing water and rock, and liquid residence time, which in turn affects the potential for rock-water and rock-solute interaction, as well as mass transfer between liquid and gas phases. This report summarizes flow- visualization experiments of water percolation through transparent replicas of a natural rock fracture. We have focused on phenomenological and exploratory experiments that can lead to a conceptual model which incorporates the important physical mechanisms that control flow.

  16. Fractures of the posterior wall of the frontal sinus: non-surgical management and complications.

    PubMed

    Villafán-Quiroga, Ronald; Cienfuegos-Monroy, Ricardo; Sierra-Martínez, Eduardo

    2010-01-01

    treatment of frontal sinus fractures remains controversial. If the posterior wall is fractured and there is cerebrospinal fluid leak, treatment seeks to restore the integrity of the dura and isolate the intracranial contents through the obliteration of the nasofrontal duct and cranialization. Another group supports nonoperative management CSF leakage is produced. The purpose is to avoid complications of meningitis, fistula and late sequelae. The difficulty lies in predicting which patients will develop complications. The aim of this study is to identify complications in patients with posterior wall fracture of the frontal sinus treated nonsurgically. an observational, cross-sectional, retrospective study was conducted with 20 patients with posterior wall fractures of the frontal sinus treated nonsurgically at the Hospital de Traumatología y Ortopedia Lomas Verdes, Service of Maxillofacial Surgery from January 2007 to October 2009. twenty patients with posterior wall fractures of the frontal sinus were included. There were 17 males and 3 females. Fractures were divided into groups according to their degree of movement and presence of cerebrospinal fluid fistula. Postoperative complications were cerebrospinal fluid fistula and frontal abscess. nonsurgical treatment has proven to be an option, although not free from complications, the most common being CSF fistula and abscess. Future comparative studies should be carried out to define therapeutic strategies usibg clinical monitoring and long-term imaging.

  17. A case of blowout fracture of the orbital floor in early childhood

    PubMed Central

    Sugamata, Akira; Yoshizawa, Naoki

    2015-01-01

    There are few reports of blowout fractures of the orbital floor in children younger than 5 years of age; in a search of the literature, we found only six reported cases which revealed the exact age, correct diagnosis, and treatment. We herein report the case of a 3-year-old boy with a blowout fracture of the orbital floor. Computed tomography showed a pure blowout fracture of the left orbital floor with a slight dislocation of the orbital contents. The patient was treated conservatively due to the absence of abnormal limitation of eye movement or enophthalmos. The patient did not develop any complications that necessitated later surgical intervention. Computed tomography at 6 months after the injury showed the regeneration of the orbital floor in the area of the fracture and no abnormalities in the left maxillary sinus. We herein present our case and the details of six other cases reported in the literature, and discuss their etiology, diagnosis, and treatment methods. PMID:26251631

  18. Late treatment of orbital fractures: a new analysis for surgical planning.

    PubMed

    Pagnoni, M; Marenco, M; Ramieri, V; Terenzi, V; Bartoli, D; Amodeo, G; Mazzoli, A; Iannetti, G

    2014-12-01

    Surgical treatment of orbital fractures should be performed without delay; in some cases acute management is not possible due to general conditions and might be delayed for weeks or months. In the latter case, the fractured fragments can consolidate improperly, causing secondary deformities of the orbital region with aesthetic and functional alteration. Surgical planning of secondary deformities is critical for adequate pre-operative planning. In the last decade an increasing number of dedicated software applications for surgical planning have been developed. Standard computed tomography (CT) or the relatively new cone beam CT can be used for diagnostic purposes, pre-surgical visual treatment outcome and virtual surgery. In this report, the authors propose their pre-operative planning analysis for surgical correction of secondary deformities of orbital fractures. The treatment of orbital fracture must, in fact, analyse not only the bone structures but the soft tissue and surrounding periorbital region. The position of the orbit in the space should be determined in relation to the surrounding structures compared to the contralateral side, if this is not affected by the trauma or pre-existing malformations.

  19. Orbit fractures: Identifying patient factors indicating high risk for ocular and periocular injury.

    PubMed

    Andrews, Brian T; Jackson, Anee Sophia; Nazir, Niaman; Hromas, Alan; Sokol, Jason A; Thurston, Todd E

    2016-02-01

    Maxillofacial trauma frequently involves the bony orbit that surrounds the ocular globe. Concomitant globe injury is a concern whenever orbit trauma occurs and in severe cases can occasionally result in vision loss. The mechanism of injury, physical exam findings, and radiographic imaging can provide useful information concerning the severity of the injury and concerns for vision loss. Using these three tools, it is hypothesized that the patient's history, physical exam, and radiographic findings can identify high-risk maxillofacial trauma patients with concomitant ocular injury. Identification of high risk patients who require comprehensive ophthalmologic evaluation may alter management and possibly preserve or restore vision. A retrospective clinical chart review was performed at a tertiary academic medical center. Subjects were identified using the institutional trauma registry. Data collected included subject demographics, patient medical records and notes, ophthalmologic testing, and radiographic imaging. The incidence of orbit fracture and concomitant ocular injury associated with the mechanism of injury, physical exam findings, and radiographic imaging was determined. Statistical analysis was performed using a chi-square and Fisher exact test. In this study, 279 subjects with orbit fractures were identified and the incidence of concomitant ocular injury was 27.6% (77 of 279). Mechanism of injury was statistically associated with an increased risk of ocular injury (P = 0.0340), with penetrating trauma being the most likely etiology. The physical exam findings of visual acuity and an afferent pupillary defect were statistically associated with ocular injury (P = 0.0029 and 0.0001, respectively). Depth of orbit fracture on radiographic imaging was statistically associated with ocular injury (P = 0.0024), with fractures extending to the posterior third of the orbit being most likely to have associated ocular injury. Maxillofacial trauma patients with orbit

  20. How reactive fluids alter fracture walls and affect shale-matrix accessibility

    NASA Astrophysics Data System (ADS)

    Fitts, J. P.; Deng, H.; Peters, C. A.

    2014-12-01

    Predictions of mass transfer across fracture boundaries and fluid flow in fracture networks provide fundamental inputs into risk and life cycle assessments of geologic energy technologies including oil and gas extraction, geothermal energy systems and geologic CO2 storage. However, major knowledge gaps exist due to the lack of experimental observations of how reactive fluids alter the pore structures and accessible surface area within fracture boundaries that control the mass transfer of organics, metals and salts, and influence fluid flow within the fracture. To investigate the fracture and rock matrix properties governing fracture boundary alteration, we developed a new flow-through cell that enables time-dependent 2D x-ray imaging of mineral dissolution and/or precipitation at a fracture surface. The parallel plate design provides an idealized fracture geometry to investigate the relationship between flow rate, reaction rate, and mineral spatial heterogeneity and variation. In the flow-cell, a carbonate-rich sample of Eagle Ford shale was reacted with acidified brine. The extent and rate of mineral dissolution were correlated with calcite abundance relative to less soluble silicate minerals. Three-dimensional x-ray tomography of the reacted fracture wall shows how calcite dissolution left behind a porous network of silicate minerals. And while this silicate network essentially preserved the location of the initial fracture wall, the pore network structures within the fracture boundary were dramatically altered, such that the accessible surface area of matrix components increased significantly. In a second set of experiments with a limestone specimen, however, the extent of dissolution and retreat of the fracture wall was not strictly correlated with the occurrence of calcite. Instead, the pattern and extent of dissolution suggested secondary causes such as calcite morphology, the presence of argillaceous minerals and other diagenetic features. Our experiments

  1. Diplopia of Pediatric Orbital Blowout Fractures: A Retrospective Study of 83 Patients Classified by Age Groups

    PubMed Central

    Su, Yun; Shen, Qin; Lin, Ming; Fan, Xianqun

    2015-01-01

    Abstract Orbital blowout fractures are relatively rare in patients under 18 years of age, but may lead to serious complications. We conducted this retrospective study to evaluate diplopia, clinical characteristics, and postoperative results in cases of orbital blowout fractures in the pediatric population. Eighty-three patients, all less than 18 years old, with orbital blowout fractures, were divided into 3 groups by age: 0 to 6 years old, 7 to 12 years old, and 13 to 18 years old. The cause of injury, fracture locations, diplopia grades, ocular motility restrictions, enophthalmos, and postoperative results were reviewed from their records. Chi-square tests, Fisher's exact analyses, analyses of variance, and logistic regressions were performed to determine characteristics associated with diplopia, and to identify factors related to residual diplopia in pediatric patients. The most common causes of injuries were traffic accidents in the 0 to 6 years old group, normal daily activities in the 7 to 12 years old group, and assaults in the 13 to 18 years old group. Floor fractures were the most common location in both the 0 to 6- and 7 to 12 years old groups, and medial-floor fractures were the most common location in the 13 to 18 years old group. The occurrence of preoperative diplopia was related to ocular motility restriction and enophthalmos, but not with the age group, the gender, the cause of injury, or the fracture locations. The time interval from injury to surgery was significant in the outcome of postoperative diplopia (P < 0.01). A statistical difference was also found in the recovery time from diplopia among the 3 age groups (P < 0.01). The characteristics of orbital blowout fracture varied among the different age groups. It was related to 2 factors, the cause of injury and fracture locations, which probably resulted from structural growth changes and differences in daily habits. Children had a slower recovery from orbital fractures, and the younger

  2. Diplopia of pediatric orbital blowout fractures: a retrospective study of 83 patients classified by age groups.

    PubMed

    Su, Yun; Shen, Qin; Lin, Ming; Fan, Xianqun

    2015-01-01

    Orbital blowout fractures are relatively rare in patients under 18 years of age, but may lead to serious complications. We conducted this retrospective study to evaluate diplopia, clinical characteristics, and postoperative results in cases of orbital blowout fractures in the pediatric population. Eighty-three patients, all less than 18 years old, with orbital blowout fractures, were divided into 3 groups by age: 0 to 6 years old, 7 to 12 years old, and 13 to 18 years old. The cause of injury, fracture locations, diplopia grades, ocular motility restrictions, enophthalmos, and postoperative results were reviewed from their records. Chi-square tests, Fisher's exact analyses, analyses of variance, and logistic regressions were performed to determine characteristics associated with diplopia, and to identify factors related to residual diplopia in pediatric patients. The most common causes of injuries were traffic accidents in the 0 to 6 years old group, normal daily activities in the 7 to 12 years old group, and assaults in the 13 to 18 years old group. Floor fractures were the most common location in both the 0 to 6- and 7 to 12 years old groups, and medial-floor fractures were the most common location in the 13 to 18 years old group. The occurrence of preoperative diplopia was related to ocular motility restriction and enophthalmos, but not with the age group, the gender, the cause of injury, or the fracture locations. The time interval from injury to surgery was significant in the outcome of postoperative diplopia (P < 0.01). A statistical difference was also found in the recovery time from diplopia among the 3 age groups (P < 0.01). The characteristics of orbital blowout fracture varied among the different age groups. It was related to 2 factors, the cause of injury and fracture locations, which probably resulted from structural growth changes and differences in daily habits. Children had a slower recovery from orbital fractures, and the younger the

  3. Acoustic and optical borehole-wall imaging for fractured-rock aquifer studies

    USGS Publications Warehouse

    Williams, J.H.; Johnson, C.D.

    2004-01-01

    Imaging with acoustic and optical televiewers results in continuous and oriented 360?? views of the borehole wall from which the character, relation, and orientation of lithologic and structural planar features can be defined for studies of fractured-rock aquifers. Fractures are more clearly defined under a wider range of conditions on acoustic images than on optical images including dark-colored rocks, cloudy borehole water, and coated borehole walls. However, optical images allow for the direct viewing of the character of and relation between lithology, fractures, foliation, and bedding. The most powerful approach is the combined application of acoustic and optical imaging with integrated interpretation. Imaging of the borehole wall provides information useful for the collection and interpretation of flowmeter and other geophysical logs, core samples, and hydraulic and water-quality data from packer testing and monitoring. ?? 2003 Elsevier B.V. All rights reserved.

  4. Nonlinear fracture mechanics-based analysis of thin wall cylinders

    NASA Technical Reports Server (NTRS)

    Brust, Frederick W.; Leis, Brian N.; Forte, Thomas P.

    1994-01-01

    This paper presents a simple analysis technique to predict the crack initiation, growth, and rupture of large-radius, R, to thickness, t, ratio (thin wall) cylinders. The method is formulated to deal both with stable tearing as well as fatigue mechanisms in applications to both surface and through-wall axial cracks, including interacting surface cracks. The method can also account for time-dependent effects. Validation of the model is provided by comparisons of predictions to more than forty full scale experiments of thin wall cylinders pressurized to failure.

  5. Spin-orbit coupling and the static polarizability of single-wall carbon nanotubes

    SciTech Connect

    Diniz, Ginetom S. Ulloa, Sergio E.

    2014-07-14

    We calculate the static longitudinal polarizability of single-wall carbon tubes in the long wavelength limit taking into account spin-orbit effects. We use a four-orbital orthogonal tight-binding formalism to describe the electronic states and the random phase approximation to calculate the dielectric function. We study the role of both the Rashba as well as the intrinsic spin-orbit interactions on the longitudinal dielectric response, i.e., when the probing electric field is parallel to the nanotube axis. The spin-orbit interaction modifies the nanotube electronic band dispersions, which may especially result in a small gap opening in otherwise metallic tubes. The bandgap size and state features, the result of competition between Rashba and intrinsic spin-orbit interactions, result in drastic changes in the longitudinal static polarizability of the system. We discuss results for different nanotube types and the dependence on nanotube radius and spin-orbit couplings.

  6. The isolated orbital floor fracture from a transconjunctival or subciliary perspective-A standardized anthropometric evaluation

    PubMed Central

    Djedovic, Gabriel; Peisker, Andre; Wohlrath, Rene; Rieger, Ulrich; Guentsch, Arndt; Gomez-Dammeier, Marta; Schultze-Mosgau, Stefan

    2016-01-01

    Background The influence of orbital fractures and their repair on the rate of deformities of the lower eyelid is an ongoing source of discussion in the literature. Most of the present studies include isolated blowout as well as combined orbital fractures. Material and Methods We present a retrospective evaluation of a series of 100 patients after isolated blowout fracture repair using reference anthropometric data on standardized photographs. Analysis included eye fissure width and height, lid sulcus height, upper lid height, upper and lower iris coverage, position of cornea to palpebra inferior, canthal tilt, scleral show, ectropion and entropion. It was clearly distinguished between operated and contralateral eyelid, whether a transconjunctival or a subciliary approach was performed and amount of fracture. Our main interests were changes of the aforementioned parameters with regards to eyelid deformities. Results Surgery per se did not significantly influence eyelid deformities. However, the surgical approach selected significantly affected eye fissure index, lower iris coverage and rate of scleral show, indicating retraction of the lower eyelid. Conclusions The standardized measurements described here are accurate and objective to evaluate postoperative results. The subciliary approach included the highest risk of lower lid retraction as compared to transconjunctival approaches. Key words:Transconjunctical approach, subciliary approach, orbital floor fracture. PMID:26595833

  7. Simulated orbital impact of multi-wall composite structures

    NASA Technical Reports Server (NTRS)

    Walker, Eve J.; Schonberg, William P.

    1992-01-01

    This paper presents the results of an experimental investigation in which several different composite materials were tested for their ability to prevent the perforation of multiwall systems under hypervelocity projectile impact. The damage in the composite specimens is compared to the damage in aluminum specimens of similar geometry and weight caused by hypervelocity projectiles with similar impact energies. The analysis shows that using composite materials in combination with metallic materials in multiwall structures can increase the protection afforded a spacecraft against perforation by orbital debris over that provided by traditional, purely metallic multiwall structures.

  8. Deterministic Domain Wall Motion Orthogonal To Current Flow Due To Spin Orbit Torque

    PubMed Central

    Bhowmik, Debanjan; Nowakowski, Mark E.; You, Long; Lee, OukJae; Keating, David; Wong, Mark; Bokor, Jeffrey; Salahuddin, Sayeef

    2015-01-01

    Spin-polarized electrons can move a ferromagnetic domain wall through the transfer of spin angular momentum when current flows in a magnetic nanowire. Such current induced control of a domain wall is of significant interest due to its potential application for low power ultra high-density data storage. In previous reports, it has been observed that the motion of the domain wall always happens parallel to the current flow – either in the same or opposite direction depending on the specific nature of the interaction. In contrast, here we demonstrate deterministic control of a ferromagnetic domain wall orthogonal to current flow by exploiting the spin orbit torque in a perpendicularly polarized Ta/CoFeB/MgO heterostructure in presence of an in-plane magnetic field. Reversing the polarity of either the current flow or the in-plane field is found to reverse the direction of the domain wall motion. Notably, such orthogonal motion with respect to current flow is not possible from traditional spin transfer torque driven domain wall propagation even in presence of an external magnetic field. Therefore the domain wall motion happens purely due to spin orbit torque. These results represent a completely new degree of freedom in current induced control of a ferromagnetic domain wall. PMID:26139349

  9. Endoscopic transnasal approach for treatment of the medial orbital blowout fracture using nasal septum graft.

    PubMed

    Ballin, Carlos R; Sava, Luiz C; Maeda, Carlos A S; Nogueira, Gustavo F; Jebahi, Yasser; Sava, Henrique W; Koladicz, Karyn R J

    2009-02-01

    We present the experience of the Ear, Nose, and Throat Department of Santa Casa de Misericórdia de Curitiba and Hospital Universitário Cajuru PUC-PR in the transnasal endoscopic approach to medial orbital blowout fractures using nasal septum grafts. Seventeen patients have undergone endoscopic repair since June 2005, and septum grafts were used to maintain the orbital contents in position. All 17 patients were treated with this method. Two patients had diplopia on immediate postoperative evaluation. This symptom was corrected with orthoptic exercises in one patient, and the other had a little residual diplopia. Postoperative computed tomography scans showed anatomic reduction in 14 of 17 cases. There were no complications in these surgeries. The transnasal endoscopic approach is a reasonable method for the treatment of medial orbital blowout fractures. Use of septum graft is another surgical alternative for this technique.

  10. Current-induced domain wall motion in Rashba spin-orbit system

    NASA Astrophysics Data System (ADS)

    Obata, Katsunori; Tatara, Gen

    2008-06-01

    Current-induced magnetic domain wall motion, induced by transfer of spin transfer effect due to exchange interaction, is expected to be useful for next generation high-density storages. Here we showed that efficient domain wall manipulation can be achieved by the introduction of Rashba spin-orbit interaction, which induces spin precession of conduction electron and acts as an effective magnetic field. Its effect on domain wall motion depends on the wall configuration. We found that the effect is significant for Bloch wall with the hard axis along the current, since the effective field works as β or fieldlike term and removes the threshold current if in extrinsic pinning is absent. For Néel wall and Bloch wall with easy axis perpendicular to Rashba plane, the effective field induces a step motion of wall corresponding to a rotation of wall plane by the angle of approximately π at current lower than intrinsic threshold. Rashba interaction would therefore be useful to assist efficient motion of domain walls at low current.

  11. Surgical Treatment of Orbital Blowout Fractures: Complications and Postoperative Care Patterns.

    PubMed

    Shew, Matthew; Carlisle, Michael P; Lu, Guanning Nina; Humphrey, Clinton; Kriet, J David

    2016-11-01

    Orbital fractures are a common result of facial trauma. Sequelae and indications for repair include enophthalmos and/or diplopia from extraocular muscle entrapment. Alloplastic implant placement with careful release of periorbital fat and extraocular muscles can effectively restore extraocular movements, orbital integrity, and anatomic volume. However, rare but devastating complications such as retrobulbar hematoma (RBH) can occur after repair, which pose a risk of permanent vision loss if not addressed emergently. For this reason, some surgeons take the precaution of admitting patients for 24-hour postoperative vision checks, while others do not. The incidence of postoperative RBH has not been previously reported and existing data are limited to case reports. Our aim was to examine national trends in postoperative management and to report the incidence of immediate postoperative complications at our institution following orbital repair. A retrospective assessment of orbital blowout fractures was undertaken to assess immediate postoperative complications including RBH. Only patients treated by a senior surgeon in the Department of Otolaryngology were included in the review. In addition, we surveyed AO North America (AONA) Craniomaxillofacial faculty to assess current trends in postoperative management. There were 80 patients treated surgically for orbital blowout fractures over a 9.5-year period. Nearly all patients were observed overnight (74%) or longer (25%) due to other trauma. Average length of stay was 17 hours for those observed overnight. There was one (1.3%) patient with RBH, who was treated and recovered without sequelae. Results of the survey indicated that a majority (64%) of responders observe postoperative patients overnight. Twenty-nine percent of responders indicated that they send patients home the same day of surgery. Performance of more than 20 orbital repairs annually significantly increased the likelihood that faculty would manage patients on

  12. Lower eyelid complications associated with transconjunctival versus subciliary approaches to orbital floor fractures.

    PubMed

    Pausch, Niels Christian; Sirintawat, Nattapong; Wagner, Rouven; Halama, Dirk; Dhanuthai, Kittipong

    2016-03-01

    The aim of this study was to compare the frequencies of lower eyelid complications after subciliary versus transconjunctival approaches to orbital floor fractures. The investigators implemented a retrospective cohort study and enrolled a sample composed of subjects who had orbital floor repair. The predictor variable was surgical approach, classified as subciliary or transconjunctival. The primary outcome variable was postoperative lower eyelid complications (ectropion, entropion, and eyelid retraction). Other variables were demographic, anatomic, or time to surgery. Descriptive and bivariate statistics were computed. Statistical significance was set at P ≤ 0.05. The study samples were composed of 346 patients (98 [28.3%] females; 225 [65%] underwent a subciliary approach) with a mean age of 42.7 ± 21.1 years. The subciliary approach was significantly linked to the higher rates of ectropion and the lower rates of entropion at 7 days and 6 months postoperatively. There was no statistically significant difference in the frequency of eyelid retraction between both groups. In the setting of orbital floor fractures, these results suggest that the use of the subciliary approach increases the frequency of ectropion, while the transconjunctival approach increases the frequency of entropion. The authors decline to comment on what the better surgical approach to the orbital floor fractures is. The selection should be based on an individual patient basis and surgeon's preference.

  13. Pseudo-Brown syndrome: a potential ophthalmologic sequela after a transcaruncular-transconjunctival approach for orbital fracture repair.

    PubMed

    de Haller, Raul; Imholz, Benoît; Scolozzi, Paolo

    2012-08-01

    To prospectively assess the incidence of orthoptic anomalies and, more specifically, the possible development of pseudo-Brown syndrome related to inferior oblique muscle (IO) myotomy after the transcaruncular-transconjunctival approach for orbital fracture repair and its effect on the possible development of annoying diplopia. We analyzed the clinical data from 14 patients with severe isolated medial wall or combined medial wall/floor fractures treated using titanium meshes placed using a transcaruncular-transconjunctival approach. All patients were assessed with a pre- and postoperative ophthalmologic examination using the following methods: prisms and alternate cover test in all 9 gaze directions, Hess-Weiss coordimetry, Maddox rod screen testing, and Harms wall deviometry. The Bielschowsky head-tilt and a forced duction test were also performed. The patients were classified into the following 2 groups: IO paretic-underaction group and non-IO paretic-underaction group. Of the 14 patients, 7 (50%) fulfilled the criteria for IO paretic-underaction. All 7 developed double vision limited to the extreme upgaze in adduction. Four patients in the non-IO paretic-underaction group had double vision limited to the extreme upgaze in abduction that was already present preoperatively. Diplopia did not interfere with the daily activities in the patients from either group. The present study has demonstrated that IO myotomy associated with the combined transcaruncular-transconjunctival approach can result in orthoptic complications. Moreover, our study has shown that the development of a pseudo-Brown syndrome related to IO underaction was not uncommon but resulted in sequela restricted to a very limited portion of the binocular field of vision. Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Iatrogenic fracture of the superomedial orbital rim during frontal trephine irrigation.

    PubMed

    Angel, Douglas; Zener, Rebecca; Rotenberg, Brian W

    2014-12-01

    Frontal sinus trephination (FST) has numerous applications in the treatment of acute and chronic sinus disease. This procedure involves making an incision at the medial aspect of the supraorbital rim and then drilling the sinus's anterior table. Placement of a frontal trephine allows for irrigation of the frontal recess in order to evacuate the frontal sinus in a minimally invasive manner. Orbital injury is a rare complication of FST. We present a case of previously unreported orbital compartment syndrome secondary to iatrogenic fracture of the superomedial orbital rim as a complication of frontal trephine irrigation. We also review the literature on the applications of FST and its associated complications, and we discuss orbital compartment syndrome as a complication of sinus surgery.

  15. Clinical and surgical implications regarding morphometric variations of the medial wall of the orbit in relation to age and gender.

    PubMed

    Morales-Avalos, Rodolfo; Santos-Martínez, Arlette Gabriela; Ávalos-Fernández, Cesia Gisela; Mohamed-Noriega, Karim; Sánchez-Mejorada, Gabriela; Montemayor-Alatorre, Adolfo; Martínez-Fernández, David A; Espinosa-Uribe, Abraham G; Mohamed-Noriega, Jibran; Cuervo-Lozano, Edgar E; Mohamed-Hamsho, Jesús; Quiroga-García, Oscar; Lugo-Guillen, Roberto A; Guzmán-López, Santos; Elizondo-Omaña, Rodrigo E

    2016-09-01

    The ethmoidal foramens are located on the medial wall of the orbit and are key reference points for intraoperative orientation. Detailed knowledge of the anatomy, bony landmarks and morphometric characteristics of the medial wall of the orbit is essential for various surgical procedures. The aim of this study was to determine the morphometric variations in the medial wall of the orbit and establish significant variations regarding age and gender. A total of 110 orbits were analyzed and subdivided by age (over or under 40 years) and gender. The distances of the medial wall of the orbit between the anterior lacrimal crest, the ethmoidal foramen, the optic canal and the interforamina were determined. Safe surgical areas were sought. Statistical tests were used to determine the differences between groups. In men, there is a safe surgical area proximal to the anterior and posterior ethmoidal foramen. In women, this area is in the posterior third of the medial wall of the orbit between the posterior ethmoidal foramen and the optic canal. Regarding variation according to age, the results of this study suggested that the anteroposterior diameter of the medial wall increases with age. This study showed that the anteroposterior total length of the medial orbit wall is similar between genders of similar age, increases with age, and has significant variations in the distances between the various structures that make up the medial orbit wall with regard to gender and age.

  16. [Medpor plus titanic mesh implant in the repair of orbital blowout fractures].

    PubMed

    Han, Xiao-hui; Zhang, Jia-yu; Cai, Jian-qiu; Shi, Ming-guang

    2011-05-10

    To study the efficacy of porous polyethylene (Medpor) plus titanic mesh sheets in the repair of orbital blowout fractures. A total of 20 patients underwent open surgical reduction with the combined usage of Medpor and titanic mesh. And they were followed up for average period of 14.5 months (range: 9 - 18). There is no infection or extrusion of medpor and titanic mesh in follow-up periods. There was no instance of decreased visual acuity at post-operation. And all cases of enophthalmos were corrected. The post-operative protrusion degree of both eyes was almost identical at less than 2 mm. The movement of eye balls was satisfactory in all directions. Diplopia disappeared in 18 cases with a cure rate of 90%, 1 case improved and 1 case persisted. Medpor plus titanic mesh implant is a safe and effective treatment in the repair of orbital blow out fractures.

  17. High Antiferromagnetic Domain Wall Velocity Induced by Néel Spin-Orbit Torques.

    PubMed

    Gomonay, O; Jungwirth, T; Sinova, J

    2016-07-01

    We demonstrate the possibility to drive an antiferromagnetic domain wall at high velocities by fieldlike Néel spin-orbit torques. Such torques arise from current-induced local fields that alternate their orientation on each sublattice of the antiferromagnet and whose orientation depends primarily on the current direction, giving them their fieldlike character. The domain wall velocities that can be achieved by this mechanism are 2 orders of magnitude greater than the ones in ferromagnets. This arises from the efficiency of the staggered spin-orbit fields to couple to the order parameter and from the exchange-enhanced phenomena in antiferromagnetic texture dynamics, which leads to a low domain wall effective mass and the absence of a Walker breakdown limit. In addition, because of its nature, the staggered spin-orbit field can lift the degeneracy between two 180° rotated states in a collinear antiferromagnet, and it provides a force that can move such walls and control the switching of the states.

  18. High Antiferromagnetic Domain Wall Velocity Induced by Néel Spin-Orbit Torques

    NASA Astrophysics Data System (ADS)

    Gomonay, O.; Jungwirth, T.; Sinova, J.

    2016-07-01

    We demonstrate the possibility to drive an antiferromagnetic domain wall at high velocities by fieldlike Néel spin-orbit torques. Such torques arise from current-induced local fields that alternate their orientation on each sublattice of the antiferromagnet and whose orientation depends primarily on the current direction, giving them their fieldlike character. The domain wall velocities that can be achieved by this mechanism are 2 orders of magnitude greater than the ones in ferromagnets. This arises from the efficiency of the staggered spin-orbit fields to couple to the order parameter and from the exchange-enhanced phenomena in antiferromagnetic texture dynamics, which leads to a low domain wall effective mass and the absence of a Walker breakdown limit. In addition, because of its nature, the staggered spin-orbit field can lift the degeneracy between two 180° rotated states in a collinear antiferromagnet, and it provides a force that can move such walls and control the switching of the states.

  19. Nonoperative Treatment of Posterior Wall Acetabular Fractures After Dynamic Stress Examination Under Anesthesia: Revisited.

    PubMed

    McNamara, Andrew R; Boudreau, John A; Moed, Berton R

    2015-08-01

    Performing an examination under general anesthesia (EUA) using dynamic stress fluoroscopy of patients with posterior wall acetabular fractures has been used as a tool to determine hip stability and the need for surgical intervention. The purpose of this study was to further evaluate the effectiveness of this technique, from a source other than its primary advocates, in patients with posterior wall acetabular fractures less than or equal to 50% who were stable on EUA and treated nonoperatively. Retrospective case series. University Level 1 Trauma Center. Seventeen patients with a posterior wall acetabular fracture stable on EUA treated nonoperatively. The patients were treated nonoperatively as guided by an EUA negative for instability. Patient follow-up averaged 30 months (range, 6-64 months). Outcome evaluation included the modified Merle d'Aubigné clinical score and the Short Musculoskeletal Function Assessment Questionnaire. Radiographic evaluation for subluxation or arthritis consisted of the 3 standard pelvic radiographs. Radiographic evaluation showed all hips to be congruent with a normal joint space. Sixteen of the 17 patients had radiographic outcomes rated as "excellent"; 1 patient was rated "good." The modified Merle d'Aubigné score (obtained in 12 patients) averaged very good, with only 1 having less than a good (graded as fair) clinical outcome. The Short Musculoskeletal Function Assessment Questionnaire scores (from 11 patients) were not significantly different from normal and were within the normal reported values for all indices and categories. There was no correlation between fracture fragment size and outcome. This study further supports the contention that a stable hip joint, as determined by EUA, after posterior wall acetabular fracture treated nonoperatively is predictive of continued joint congruity, an excellent radiographic outcome, and good-to-excellent early clinical and functional outcomes. Therapeutic Level IV. See Instructions for

  20. The isolated orbital floor fracture from a transconjunctival or subciliary perspective-A standardized anthropometric evaluation.

    PubMed

    Raschke, Gregor; Djedovic, Gabriel; Peisker, Andre; Wohlrath, Rene; Rieger, Ulrich; Guentsch, Arndt; Gomez-Dammeier, Marta; Schultze-Mosgau, Stefan

    2016-01-01

    The influence of orbital fractures and their repair on the rate of deformities of the lower eyelid is an ongoing source of discussion in the literature. Most of the present studies include isolated blow-out as well as combined orbital fractures. We present a retrospective evaluation of a series of 100 patients after isolated blow-out fracture repair using reference anthropometric data on standardized photographs. Analysis included eye fissure width and height, lid sulcus height, upper lid height, upper and lower iris coverage, position of cornea to palpebra inferior, canthal tilt, scleral show, ectropion and entropion. It was clearly distinguished between operated and contralateral eyelid, whether a transconjunctival or a subciliary approach was performed and amount of fracture. Our main interests were changes of the aforementioned parameters with regards to eyelid deformities. Surgery per se did not significantly influence eyelid deformities. However, the surgical approach selected significantly affected eye fissure index, lower iris coverage and rate of scleral show, indicating retraction of the lower eyelid. The standardized measurements described here are accurate and objective to evaluate postoperative results. The subciliary approach included the highest risk of lower lid retraction as compared to transconjunctival approaches.

  1. Primary orbital fracture repair: development and validation of tools for morphologic and functional analysis.

    PubMed

    Hontscharuk, Rayisa; Fialkov, Jeffrey A; Binhammer, Paul A; McMillan, Catherine R; Antonyshyn, Oleh

    2012-07-01

    The purpose of this study was to develop and validate a technique for objective quantitative evaluation of outcomes of orbital reconstruction. Facial three-dimensional images were captured using a Vectra three-dimensional camera. Morphometric analysis was based on interactive anthropometric identification. The analysis was applied to a population of healthy adults (n = 13) and a population of patients following primary repair of unilateral orbital fractures (n = 13). Morphologic results following reconstruction were evaluated by identifying residual asymmetries. All subjects further completed the Derriford Appearance Questionnaire and the Orbital Appearance and Function Questionnaire.Normative reference values for periorbital asymmetry were determined in a reference population. The mean asymmetry was less than 1.6 mm for each measured morphologic feature. In the trauma population, primary orbital reconstruction effectively restored normal periorbital symmetry in 16 of 20 measured parameters. The fracture population showed no significant differences in the degree of asymmetry in globe projection, lower eyelid position, or ciliary margin length.The overall DAS59 scores were significantly higher in the fracture population (P = 0.04). This was due to significantly higher physical distress and dysfunction scores (P = 0.02), as well as a trend toward higher general and social self-consciousness scores (P = 0.06). No significant difference in facial self-consciousness was noted (P = 0.21). Thus, although primary orbital reconstruction was effective in restoring periorbital morphology, patients still experienced a higher level of physical distress and dysfunction than their nontraumatized counterparts. This was in accordance with patient self-report, which indicated that a greater percentage of patients were significantly bothered by functional outcomes postoperatively as opposed to appearance.

  2. Single-donor allogeneic platelet fibrin glue and osteoconductive scaffold in orbital floor fracture reconstruction.

    PubMed

    Chen, Tim-Mo; Tzeng, Yuan-Sheng; Tsai, Jui-Che; Burnouf, Thierry

    2013-03-01

    Commonly used materials for orbital floor fracture reconstruction include autologous cranial bone graft and titanium mesh. We have evaluated here a biomaterial combining biphasic calcium phosphate (hydroxyapatite [HA]/β-tricalcium phosphate [TCP]) osteoconductive scaffold with single-donor allogeneic platelet fibrin glue. The study was conducted on 10 consecutive patients with a follow-up of up to 4 years. Platelet fibrin glue was prepared by mixing equal volumes of single-donor platelet-rich plasma and cryoprecipitate with HA/β-TCP followed by activation with human thrombin prepared by plasma activation. Postoperative evaluations included serial photographs, repeated physical examination, and 3-dimensional computed tomography scan performed 2 years after surgery. The fibrin-rich platelet biomaterial was easy to mold and to apply on the surgical site allowing the surgeon to sculpt accurately the bone defect, providing mechanical stability while avoiding spillage of the scaffold. No infection of the orbit or extrusion of HA/β-TCP was observed. Ocular motility was normal, and no diplopia or enophthalmos of the injured orbit was noted. Coronal computed tomography scans of the reconstructed orbits revealed good restoration of the orbital floor defect in all 10 patients. The use of single-donor platelet fibrin glue combined with an osteoconductive scaffold offers a valuable alternative to autologous cranial bone graft or titanium mesh in the reconstruction of orbital floor bone defect.

  3. Transconjunctival orbital decompression in Graves' ophthalmopathy: lateral wall approach ab interno

    PubMed Central

    Paridaens, D.; Verhoeff, K.; Bouwens, D.; van den Bosch, W. A

    2000-01-01

    AIMS—A modified surgical technique is described to perform a one, two, or three wall orbital decompression in patients with Graves' ophthalmopathy.
METHODS—The lateral wall was approached ab interno through a "swinging eyelid" approach (lateral canthotomy and lower fornix incision) and an extended periosteum incision along the inferior and lateral orbital margin. In addition, the orbital floor and medial wall were removed when indicated. To minimise the incidence of iatrogenic diplopia, the lateral and medial walls were used as the first surfaces of decompression, leaving the "medial orbital strut" intact. During 1998, this technique was used in a consecutive series of 19 patients (35 orbits) with compressive optic neuropathy (six patients), severe exposure keratopathy (one patient), or disfiguring/congestive Graves' ophthalmopathy (12 patients).
RESULTS—The preoperative Hertel value (35 eyes) was on average 25 mm (range 19-31 mm). The mean proptosis reduction at 2 months after surgery was 5.5 mm (range 3-7 mm). Of the total group of 19 patients, iatrogenic diplopia occurred in two (12.5%) of 16 patients who had no preoperative diplopia or only when tired. The three other patients with continuous preoperative diplopia showed no improvement of double vision after orbital decompression, even when the ocular motility (ductions) had improved. In the total group, there was no significant change of ductions in any direction at 2 months after surgery. All six patients with recent onset compressive optic neuropathy showed improvement of visual acuity after surgery. No visual deterioration related to surgery was observed in this study. A high satisfaction score (mean 8.2 on a scale of 1 to 10) was noted following the operation.
CONCLUSION—This versatile procedure is safe and efficacious, patient and cost friendly. Advantages are the low incidence of induced diplopia and periorbital hypaesthesia, the hidden and small incision, the minimal surgical

  4. Experiments on fracture toughness of thick-wall cylinder for modes I, II, III

    SciTech Connect

    Saegusa, T.; Urabe, N.; Ito, C.; Shirai, K.; Kosaki, A.

    1999-07-01

    There have been few data on fracture toughness for Mode 2 and 3 as compared with those for Mode 1. Experimental data on fracture toughness of plates made of ductile cast iron (ASTM A874-89) and forged steel (ASME SA350 LF5 C1.1) were obtained at a temperature range from 77K to 293K for Mode 1, 2 and 3. The results showed: J{sub IC} < J{sub IIC} < J{sub IIIC}, and K{sub IC} < K{sub IIC} K{sub IIIC}. Integrity of a thick-wall cylinder with artificial flaw was demonstrated against brittle fracture at 233K for Mode 1, 2 and 3, which is one of the design requirements of containers shipping radioactive materials.

  5. Fracture toughness of irradiated candidate materials for ITER first wall/blanket structures: Summary report

    SciTech Connect

    Alexander, D.J.; Pawel, J.E.; Grossbeck, M.L.; Rowcliffe, A.F.

    1996-04-01

    Disk compact specimens of candidate materials for first wall/blanket structures in ITER have been irradiated to damage levels of about 3 dpa at nominal irradiation temperatures of either 90 250{degrees}C. These specimens have been tested over a temperature range from 20 to 250{degrees}C to determine J-integral values and tearing moduli. The results show that irradiation at these temperatures reduces the fracture toughness of austenic stainless steels, but the toughness remains quite high. The toughness decreases as the temperature increases. Irradiation at 250{degrees}C is more damaging that at 90{degrees}C, causing larger decreases in the fracture toughness. The ferritic-martensitic steels HT-9 and F82H show significantly greater reductions in fracture toughness that the austenitic stainless steels.

  6. Influence of kinesiologic tape on postoperative swelling, pain and trismus after zygomatico-orbital fractures.

    PubMed

    Ristow, Oliver; Pautke, Christoph; Victoria Kehl; Koerdt, Steffen; Schwärzler, Katharina; Hahnefeld, Lilian; Hohlweg-Majert, Bettina

    2014-07-01

    Surgical treatment of zygomatico-orbital (ZO) fractures is a common procedure in maxillofacial surgery. Often accompanied by pain, trismus and swelling, postoperative morbidity is a major disadvantage, affecting patients' quality of life. The appliance of kinesiologic tape (KT) improves the blood and lymph flow, removing congestions of lymphatic fluid and haemorrhages. The aim of this study was to find out if the application of kinesiologic tape prevents or improves swelling, pain and trismus after zygomatico-orbital fracture surgery, improving patients' postoperative quality of life. A total of 30 patients were assigned for treatment of zygomatico-orbital fractures and were randomly divided into treatment either with or without kinesiologic tape. Tape was applied directly after surgery and maintained for at least 5 days postoperatively. Facial swelling was quantified using a five-line measurement at six specific time points. Pain and degree of mouth opening was measured. Patient's subjective feeling and satisfaction was queried. The results of this study show that application of kinesiologic tape after zygomatico-orbital surgery significantly reduced the incidence of swelling with an earlier swelling maximum, and decreased the maximum turgidity for more than 60% during the first 2 days after surgery. Although, kinesiologic tape has no significant influence on pain control and trismus, mouth opening increased earlier after operation in the kinesiologic tape group compared to the no-kinesiologic tape group. Furthermore, patients with kinesiologic tape felt significantly lower morbidity than those without kinesiologic tape. Therefore kinesiologic tape is a promising, simple, less traumatic, economical approach, which is free from adverse reaction and improves patients' quality of life.

  7. Prototyping for the treatment of late zygomatic-orbital fracture: A case report.

    PubMed

    do Ó Silva, Amanda Lúcio; Dias, Isabella Jardelino; Grempel, Rafael Grotta; de Morais, Hécio Henrique Araújo; da Silva Oliveira Brito, Nadja Maria; de Castro Gomes, Daliana Queiroga

    2017-01-01

    Zygomatic-orbital complex fractures are the most common facial traumas that can result in severe esthetic and functional sequelae. Surgical correction of these fractures is a delicate approach and prototyping is an excellent tool to facilitate this procedure. A 27-year-old man, a motorcycle accident victim, was hospitalized in the intensive care unit for 30days. After this period, facial fractures were treated surgically, leaving sequelae such as enophthalmos, dystopia and loss of projection of the zygomatic arch. A second intervention was planned after one year for reconstruction of the orbit with the help of prototyping. Better outcomes were achieved than in the first intervention. This report permits to compare the result of conventional surgery and the use of a prototype in the same patient. Noticeably better outcomes were achieved with the second approach. Prototyping made the surgical procedure more predictable and reduced operative time because of the possibility of using preshaped titanium plates. Prototyping was found to be an excellent option to overcome the deficiencies of the conventional technique, recovering the functional and esthetic characteristics of the patient's face and ensuring a markedly satisfactory outcome. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  8. Orbital roof fracture and orbital cellulitis secondary to halo pin penetration: case report.

    PubMed

    Menon, K Venugopal; Al Rawi, Asif Esam; Taif, Sawsan; Al Ghafri, Khalifa; Mollahalli, Kishore Kumar

    2015-02-01

    Study Design Case report. Objective To report and discuss a rare complication after a patient was treated conservatively with a halo vest. Methods A 51-year-old man sustained a hangman's injury of the C2 vertebra following a motor vehicle collision. He was treated conservatively in a halo vest appliance and following mobilization was discharged from the hospital. Two weeks after discharge, the patient presented to the emergency department complaining of proptosis, ptosis, diplopia, and pin loosening. He was readmitted to the hospital, the halo vest was removed, and urgent imaging studies including computed tomography scan and magnetic resonance imaging were performed. They revealed that one of the halo pins had penetrated the orbital roof with active infection of the extraocular soft tissues. In consultation with the ophthalmologist, he was treated conservatively with antibiotics for 10 days. Results His ophthalmologic complaints resolved gradually and his eye returned to normal appearance and function. In the meantime, he was immobilized in a sterno-occipital mandibular immobilizer brace. Conclusion Though rare, penetrating injuries after cranial pin insertion can occur. Halo devices must be applied by, or under close supervision of, experienced personnel to avoid such complications, and halo vests should be reviewed frequently to detect such incidents early.

  9. Modeling gravity-driven fingering in rough-walled fractures using modified percolation theory

    SciTech Connect

    Glass, R.J.

    1992-12-31

    Pore scale invasion percolation theory is modified for imbibition of.wetting fluids into fractures. The effects of gravity, local aperture field geometry, and local in-plane air/water interfacial curvatureare included in the calculation of aperture filling potential which controls wetted structure growth within the fracture. The inclusion of gravity yields fingers oriented in the direction of the gravitational gradient. These fingers widen and tend to meander and branch more as the gravitational gradient decreases. In-plane interfacial curvature also greatly affects the wetted structure in both horizontal and nonhorizontal fractures causing the formation of macroscopic wetting fronts. The modified percolation model is used to simulate imbibition into an analogue rough-walled fracture where both fingering and horizontal imbibition experiments were previously conducted. Comparison of numerical and experimental results showed reasonably good agreement. This process oriented physical and numerical modeling is-a necessary step toward including gravity-driven fingering in models of flow and transport through unsaturated, fractured rock.

  10. The management of the displaced medial wall in complex acetabular fractures using plates and additional cerclage.

    PubMed

    Park, Myung-sik; Yoon, Sun Jung; Park, Jong-hyuk; Choi, Seung-min

    2013-01-01

    Reduction for displaced quadrilateral plates in complicated acetabular fractures is difficult and requires wide exposure. The purpose of this study is to assess the usefulness of the additional cable in this complicated fracture and to evaluate the potential danger of compressing the superior gluteal artery and nerve with cable application. We evaluated 31 hips (these included 25 hips with fractures of both columns, two posterior wall and column fractures, three anterior column and posterior hemitransverse fractures, and one high T-shaped fracture) with an average six-year follow-up. Clinical outcomes were evaluated using a modification of the Matta grading system and radiographic arthritic grades. We assessed the postoperative clinical outcomes in relation with other variables such as anatomical reduction, delayed operation, seagull sign, and femoral head injuries. We determined whether the superior gluteal artery and nerve were compressed by cerclage with the help of femoral angiography and EMG. Clinical outcomes were graded as very good to excellent for 18 patients, good for five, fair for three 
and poor for five. Preoperative femoral head injury (P = 0.011), a seagull sign (P = 0.001), poor reduction (P = 0.015), and delayed reduction (P = 0.05) were found to statistically influence clinical results. We found that there were no injuries to the superior gluteal artery and nerve in spite of using a cable. Cerclage methods can be useful for initial reduction of displaced medial plates in acetabular fractures. These methods reduce operation time and blood loss as compared with other methods.

  11. [Orbital emphysema: radiologic and ophthalmologic findings].

    PubMed

    Solanas-Álava, Susana; Rodríguez-Marco, Nelson Arturo; Artigas-Martín, José María; Fernández-Larripa, Sonia

    2017-01-01

    Orbital emphysema, or the presence of air in orbital tissues, is normally associated with an injury although it can arise when a Valsalva maneuver causes an increase in upper airway pressure. This potential complication of an orbital wall fracture, usually in the ethmoid bone, occurs in 50% of such cases. On fracture, air passes from the nasal fossa, sinuses, or subcutaneous tissue. The condition is benign and transient in most cases, and loss of vision is rare. No protocol for treating orbital emphysema with serious complications in which vision is affected has been established. We report 9 cases of orbital emphysema, describing events leading to the fractures, radiologic findings, and treatments.

  12. [Craniofacial fractures].

    PubMed

    Benech, A; Gerbino, G

    1990-12-01

    Results of early combined maxillo-facial and neurosurgical treatment of 53 craniofacial fractures are referred. The fracture location was in 31 cases central midfrontal, 10 lateral supraorbital and 12 combined central and lateral fractures. 35 fractures interested the floor and the posterior wall of frontal sinus, lacerating the underlying dura and cortical tissue. In 19 fractures orbital displacement was present. The key points in the management of these patients are: 1) Early (within 1 to 5 days) and one stage neurosurgical-maxillofacial procedure. Immediate intervention is indicated only in case of evolutive neurological lesions; 2) wide exposition of all the injuries through bicoronal incision and bone flap; 3) assessment of fractures pattern and amount of bone loss; 4) reconstruction of craniofacial frame with osteosynthesis and autologous bone grafts (35 cases iliac crest, 7 split calvarial graft); 5) interosseous wiring is used in sutured mosaic, small bone fragments and intraoperative temporary fixation; miniplates are used for rigid fixation of craniofacial pillars; 6) for optimal cosmetic result reconstruction of supraorbital ridge, nasoglabellar region and zygomatic arch is essential; 7) fractures involving the sinus floor, posterior wall and the nasofrontal duct result in direct communication between the nose and intracranial cavity with high risk of infection and mucocele formation. Cranialization of the sinus removing the posterior wall and all the mucosa is mandatory. The nasofrontal duct, the floor and sinus dead space are obliterated with autologous bone chips. Osteoneogenesis occurred in all the cases.

  13. Cosmic bubble and domain wall instabilities II: fracturing of colliding walls

    SciTech Connect

    Braden, Jonathan; Bond, J. Richard; Mersini-Houghton, Laura

    2015-08-26

    We study collisions between nearly planar domain walls including the effects of small initial nonplanar fluctuations. These perturbations represent the small fluctuations that must exist in a quantum treatment of the problem. In a previous paper, we demonstrated that at the linear level a subset of these fluctuations experience parametric amplification as a result of their coupling to the planar symmetric background. Here we study the full three-dimensional nonlinear dynamics using lattice simulations, including both the early time regime when the fluctuations are well described by linear perturbation theory as well as the subsequent stage of fully nonlinear evolution. We find that the nonplanar fluctuations have a dramatic effect on the overall evolution of the system. Specifically, once these fluctuations begin to interact nonlinearly the split into a planar symmetric part of the field and the nonplanar fluctuations loses its utility. At this point the colliding domain walls dissolve, with the endpoint of this being the creation of a population of oscillons in the collision region. The original (nearly) planar symmetry has been completely destroyed at this point and an accurate study of the system requires the full three-dimensional simulation.

  14. Cosmic bubble and domain wall instabilities II: fracturing of colliding walls

    SciTech Connect

    Braden, Jonathan; Bond, J. Richard; Mersini-Houghton, Laura E-mail: bond@cita.utoronto.ca

    2015-08-01

    We study collisions between nearly planar domain walls including the effects of small initial nonplanar fluctuations. These perturbations represent the small fluctuations that must exist in a quantum treatment of the problem. In a previous paper, we demonstrated that at the linear level a subset of these fluctuations experience parametric amplification as a result of their coupling to the planar symmetric background. Here we study the full three-dimensional nonlinear dynamics using lattice simulations, including both the early time regime when the fluctuations are well described by linear perturbation theory as well as the subsequent stage of fully nonlinear evolution. We find that the nonplanar fluctuations have a dramatic effect on the overall evolution of the system. Specifically, once these fluctuations begin to interact nonlinearly the split into a planar symmetric part of the field and the nonplanar fluctuations loses its utility. At this point the colliding domain walls dissolve, with the endpoint of this being the creation of a population of oscillons in the collision region. The original (nearly) planar symmetry has been completely destroyed at this point and an accurate study of the system requires the full three-dimensional simulation.

  15. A rare case of a broken dental bur perforating the medial orbital wall without damaging the eye.

    PubMed

    Matsuzaki, Kyoichi; Aoki, Tomoko; Oji, Tomito; Nagashima, Hayato; Tsue, Chisato; Maki, Risa; Kishi, Kazuo

    2016-01-01

    Rotating instruments used in the fields of dentistry and oral surgery operate at high speeds. Therefore, if small particles are projected and strike the orbit, injuries of varying severity can occur. We report here a case in which a broken dental bur pierced into the orbit. The bur fortunately did not damage the eyeball and stopped after penetration of the medial orbital wall. The subject was a 27-year-old dental assistant and not wearing protective eyewear. A foreign body had penetrated the medial wall of the right orbit and the tip had reached the ethmoid sinus. The medial orbital wall was exposed subperiosteally after dissection of the medial canthal ligament, and the foreign body was removed. Although the importance of protective eyewear had been advocated, eye protection compliance differed by region and dental personnel. Eye protection use needs to increase in not only dentists but also other dental personnel.

  16. Maxillofacial Fractures: Midface and Internal Orbit-Part I: Classification and Assessment.

    PubMed

    Mast, Gerson; Ehrenfeld, Michael; Cornelius, Carl-Peter; Litschel, Ralph; Tasman, Abel-Jan

    2015-08-01

    Fractures of the midface and internal orbit occur isolated or in combination with other injuries. Frequently, the patients are first seen in emergency rooms responsible for the coordination of initial diagnostic procedures, followed by the transfer to specialties for further treatment. It is, therefore, important for all physicians treating facial trauma patients to understand the basic principles of injuries to the midface. Thus, this article aims to describe the anatomy and the current classification systems in use, the related clinical symptoms, and the essential diagnostic measures to obtain precise information about the injury pattern.

  17. Cracking characteristics of a habitable module pressure wall following orbital debris penetration

    NASA Technical Reports Server (NTRS)

    Schonberg, William P.

    1994-01-01

    All long-duration spacecraft in low-earth-orbit are subject to high speed impacts by meteoroids and pieces of orbital debris. The threat of damage from such impacts is a significant design consideration in the development of long duration earth-orbiting spacecraft. This report presents the results of a study whose objective was to develop an empirical model to predict the magnitude of the various cracking and through-hole creation phenomena accompanying a habitable module penetration. The significance of the work performed is that the model predictions can be fed directly into a survivability analysis to determine whether or not module unzipping would occur under a specific set of impact conditions. The likelihood of module unzipping over a structure's lifetime can also be determined in such an analysis. In addition, effective hole size predictions can be used as part of a survivability analysis to determine the time available for module evacuation prior to the onset of incapacitation due to air loss. Some of the phenomena considered include maximum petal length, maximum tip-to-tip crack distance, depth of petal deformation, number of cracks formed, orientation of the maximum tip-to-tip distance with respect to the inner wall grain direction, and the effective inner wall hole diameter.

  18. Classical versus custom orbital wall reconstruction: Selected factors regarding surgery and hospitalization.

    PubMed

    Zieliński, Rafał; Malińska, Marta; Kozakiewicz, Marcin

    2017-05-01

    Nowadays, in orbital wall reconstruction, maxillofacial surgeons have the possibility to treat patients in modern ways such as with individual implants. Nevertheless, conventional treatment including standard titanium mesh shaped during the surgical procedure is also widely used. The aim of this study was to compare the above methods of orbital wall reconstructions. In the first group (39 cases), patients were treated by means of computer-aided design/computer-aided manufacturing (CAD/CAM) milled individual implants made of ultra-high-molecular-weight polyethylene, dioxide zirconium and rapid prototyping titanium mesh pre-bent on an ABS model made by a three-dimensional (3D) printer. In the second group (54 cases), intraoperative bending of titanium mesh was implemented. Ophthalmologic outcomes were the same in both groups. In patients who had greater destruction of the orbit, surgical procedures were longer regardless of the material used for individual implants (p < 0.05). Time of surgery was shorter in patients in whom individual implants were used. Intraoperative bleeding was higher in patients who were treated using intraoperative bending titanium mesh (p < 0.01). Application of CAD/CAM techniques do not give better ophthalmologic results in reference center but improve patient condition postoperatively. For this reason, CAD/CAM is a safer treatment method for patients. Copyright © 2017. Published by Elsevier Ltd.

  19. Non-Darcian flow experiments of shear-thinning fluids through rough-walled rock fractures

    NASA Astrophysics Data System (ADS)

    Rodríguez de Castro, Antonio; Radilla, Giovanni

    2016-11-01

    Understanding non-Darcian flow of shear-thinning fluids through rough-walled rock fractures is of vital importance in a number of industrial applications such as hydrogeology or petroleum engineering. Different laws are available to express the deviations from linear Darcy law due to inertial pressure losses. In particular, Darcy's law is often extended through addition of quadratic and cubic terms weighted by two inertial coefficients depending on the strength of the inertia regime. The relations between the effective shear viscosity of the fluid and the apparent viscosity in porous media when inertial deviations are negligible were extensively studied in the past. However, only recent numerical works have investigated the superposition of both inertial and shear-thinning effects, finding that the same inertial coefficients obtained for non-Darcian Newtonian flow applied in the case of shear-thinning fluids. The objective of this work is to experimentally validate these results, extending their applicability to the case of rough-walled rock fractures. To do so, flow experiments with aqueous polymer solutions have been conducted using replicas of natural fractures, and the effects of polymer concentration, which determine the shear rheology of the injected fluid, have been evaluated. Our findings show that the experimental pressure loss-flow rate data for inertial flow of shear-thinning fluids can be successfully predicted from the empirical parameters obtained during non-Darcian Newtonian flow and Darcian shear-thinning flow in a given porous medium.

  20. The stability of steady motion of magnetic domain wall: Role of higher-order spin-orbit torques

    SciTech Connect

    He, Peng-Bin Yan, Han; Cai, Meng-Qiu; Li, Zai-Dong

    2015-12-14

    The steady motion of magnetic domain wall driven by spin-orbit torques is investigated analytically in the heavy/ferromagnetic metal nanowires for three cases with a current transverse to the in-plane and perpendicular easy axis, and along the in-plane easy axis. By the stability analysis of Walker wall profile, we find that if including the higher-order spin-orbit torques, the Walker breakdown can be avoided in some parameter regions of spin-orbit torques with a current transverse to or along the in-plane easy axis. However, in the case of perpendicular anisotropy, even considering the higher-order spin-orbit torques, the velocity of domain wall cannot be efficiently enhanced by the current. Furthermore, the direction of wall motion is dependent on the configuration and chirality of domain wall with a current along the in-plane easy axis or transverse to the perpendicular one. Especially, the direction of motion can be controlled by the initial chirality of domain wall. So, if only involving the spin-orbit mechanism, it is preferable to adopt the scheme of a current along the in-plane easy axis for enhancing the velocity and controlling the direction of domain wall.

  1. Current induced domain wall dynamics in the presence of spin orbit torques

    NASA Astrophysics Data System (ADS)

    Boulle, O.; Buda-Prejbeanu, L. D.; Jué, E.; Miron, I. M.; Gaudin, G.

    2014-05-01

    Current induced domain wall (DW) motion in perpendicularly magnetized nanostripes in the presence of spin orbit torques is studied. We show using micromagnetic simulations that the direction of the current induced DW motion and the associated DW velocity depend on the relative values of the field like torque (FLT) and the Slonczewski like torques (SLT). The results are well explained by a collective coordinate model which is used to draw a phase diagram of the DW dynamics as a function of the FLT and the SLT. We show that a large increase in the DW velocity can be reached by a proper tuning of both torques.

  2. Current induced domain wall dynamics in the presence of spin orbit torques

    SciTech Connect

    Boulle, O. Buda-Prejbeanu, L. D.; Jué, E.; Miron, I. M.; Gaudin, G.

    2014-05-07

    Current induced domain wall (DW) motion in perpendicularly magnetized nanostripes in the presence of spin orbit torques is studied. We show using micromagnetic simulations that the direction of the current induced DW motion and the associated DW velocity depend on the relative values of the field like torque (FLT) and the Slonczewski like torques (SLT). The results are well explained by a collective coordinate model which is used to draw a phase diagram of the DW dynamics as a function of the FLT and the SLT. We show that a large increase in the DW velocity can be reached by a proper tuning of both torques.

  3. The use of cervical vertebrae plates for cortical substitution in posterior wall acetabular fractures.

    PubMed

    Schwab, Joseph M; Zebrack, John; Schmeling, Gregory J; Johnson, Jennifer

    2011-09-01

    We report a new technique for operative fixation of posterior wall acetabular fractures that require cortical substitution. This technique uses cervical vertebrae plates that are H-shaped as an alternative to the combination of standard locking or nonlocking pelvic reconstruction plates and cortical substitution plates, ie, spring plates. We believe this technique provides a more robust structural support with the plate acting as a cortical substitute in comminuted fracture patterns. Compared with pelvic reconstruction plates, cervical vertebrae plates are almost twice as wide. Additionally, the plate configuration allows more screws per unit length compared with pelvic reconstruction plates, potentially providing more points of fixation. Finally, cost comparison of the two plates shows the cervical vertebrae plates to be less expensive than standard pelvic reconstruction plates. Our series of 23 consecutive patients shows outcomes similar to the published literature for standard pelvic reconstruction plates, and initial results show no early hardware failure.

  4. Plasma membrane ultrastructure during plant protoplast plasmolysis, isolation and wall regeneration: a freeze-fracture study.

    PubMed

    Wilkinson, M J; Northcote, D H

    1980-04-01

    The freeze-fracture morphology of the plasma membrane of cells and isolated protoplasts of plant callus suspensions has been investigated. Plasmolysis of suspension cells leads to the formation of 2 types of hexagonal arrays of intramembrane particles situated on the inner fracture face (PF). These arrays are interpreted as proteins that have 'crystallized' in the plane of the membrane as the area of surrounding lipid bilayer is reduced during protoplast retraction from the cell wall. Time-course studies have revealed no positive relationship between the distribution of hexagonal arrays and the occurrence of microfibrils regenerated around isolated protoplasts during periods of culture. No evidence for the specialized transport functions attributed to hexagonal arrays of plant cells by previous workers has been found.

  5. Examination of Relationship Between Photonic Signatures and Fracture Strength of Fused Silica Used in Orbiter Windows

    NASA Technical Reports Server (NTRS)

    Yost, William T.; Cramer, K. Elliott; Estes, Linda R.; Salem, Jonathan A.; Lankford, James, Jr.; Lesniak, Jon

    2011-01-01

    A commercially available grey-field polariscope (GFP) instrument for photoelastic examination is used to assess impact damage inflicted upon the outermost pane of the orbiter windows. Four categories of damage: hyper-velocity impacts that occur during space-flight (HVI); hypervelocity impacts artificially made at the Hypervelocity Impact Technology Facility (HIT-F); impacts made by larger objects falling onto the pane surface to simulate dropped items on the window during service/storage of vehicle (Bruises); and light scratches from dull objects designed to mimic those that might occur by dragging a dull object across the glass surface (Chatter Checks) are examined. The damage sites are cored from fused silica window carcasses, examined with the GFP and other methodologies, and broken using the ASTM Standard C1499-09 to measure the fracture strength. A correlation is made between the fracture strength and damage-site measurements including geometrical measurements and GFP measurements of photoelastic retardation (stress patterns) surrounding the damage sites. An analytical damage model to predict fracture strength from photoelastic retardation measurements is presented and compared with experimental results.

  6. Treatment of orbital floor fracture using a periosteum-polymer complex.

    PubMed

    Asamura, Shinichi; Ikada, Yoshito; Matsunaga, Kazuhide; Wada, Mitsuhiro; Isogai, Noritaka

    2010-04-01

    Various materials for the reconstruction of bone defects in orbital floor fractures have been developed and applied clinically. Recently, reconstruction using polymers, in place of autologous bone and artificial materials, has been actively introduced, but there are problems, such as the size of reconstructable bone defects and the decomposition rate of polymers. A basic study was performed on bone regeneration using a periosteum-polymer complex produced by attaching periosteum to a biodegradable polymer sheet. In this study, patients with orbital floor fractures were evaluated clinically who had undergone reconstruction of orbital floor defects of the using a periosteum-polymer complex produced by applying periosteum to an Hydroxyapatite-[poly (l-lactide-epsilon-caprolactone)](HA-P (CL/LA)) sheet and the ilium in the previous 3 years. A bone defect of less than 2.5cm(2) area was defined as small, that of 2.5-4cm(2) as intermediate, and that of more than 4cm(2) as a large bone defect. For small bone defects, hypoaesthesia in the infraorbital nerve was observed in one patient each of the periosteum-polymer complex and ilium groups. Regarding intermediate bone defects, diplopia and hypoaesthesia in the infraorbital nerve were observed in one patient in each of the two groups. For large bone defects, diplopia was observed in one patient each for the periosteum-polymer complex and ilium groups, and hypoaesthesia of the infraorbital nerve was only detected in one patient of the former group. Not more than 2mm of enophthalmos was detected in any patient. The anatomical eyeball position and eyeball movement were normal after surgical treatment using the periosteum-polymer complex, just as in reconstruction using autologous bone.

  7. Diplopia and ocular motility in orbital blow-out fractures: 10-year retrospective study.

    PubMed

    Alhamdani, Faaiz; Durham, Justin; Greenwood, Mark; Corbett, Ian

    2015-09-01

    To investigate diplopia (binocular single vision [BSV] test) and ocular motility (uniocular field of fixation [UFOF] test) characteristics in blow-out fractures of the orbit and their value in fracture management. Patients with isolated blow-out fractures treated from 2000 to 2010 were included. BSV scores were stratified into three categories: low BSV category (0-60); moderate BSV category (61-80), and high BSV category (81-100). UFOF scores were also divided into three categories: low score (60-240), moderate score (241-270), and high score (271-365) categories. A total of 183 patients (106 surgically and 77 conservatively managed) met the inclusion criteria. There was no significant improvement in BSV postoperatively in surgically managed patients with preoperatively high BSV, whereas there was significant improvement (p < 0.05) for the high BSV category in the conservative group. Preoperative BSV was found to be significantly related (p < 0.05) to postoperative BSV, subjective diplopia outcome, follow-up time, and number of follow-up visits. However, improvement of BSV score in the surgical group was not found to be significantly correlated with subjective outcome in relation to diplopia. Preoperative UFOF score has no influence on subjective outcome in relation to diplopia. Surgical timing, approach, and choice of implant material were not found to be statistically related to final diplopia outcome, follow-up time, or number of follow-up visits. BSV is better correlated with diplopia outcome, follow-up time, and number of follow-up visits than is UFOF. On the basis of this study, surgical intervention would not be recommended for blow-out fracture cases with BSV score >80% for correction of diplopia alone. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  8. Orbital Wall Reconstruction with Two-Piece Puzzle 3D Printed Implants: Technical Note

    PubMed Central

    Mommaerts, Maurice Y.; Büttner, Michael; Vercruysse, Herman; Wauters, Lauri; Beerens, Maikel

    2015-01-01

    The purpose of this article is to describe a technique for secondary reconstruction of traumatic orbital wall defects using titanium implants that act as three-dimensional (3D) puzzle pieces. We present three cases of large defect reconstruction using implants produced by Xilloc Medical B.V. (Maastricht, the Netherlands) with a 3D printer manufactured by LayerWise (3D Systems; Heverlee, Belgium), and designed using the biomedical engineering software programs ProPlan and 3-Matic (Materialise, Heverlee, Belgium). The smaller size of the implants allowed sequential implantation for the reconstruction of extensive two-wall defects via a limited transconjunctival incision. The precise fit of the implants with regard to the surrounding ledges and each other was confirmed by intraoperative 3D imaging (Mobile C-arm Systems B.V. Pulsera, Philips Medical Systems, Eindhoven, the Netherlands). The patients showed near-complete restoration of orbital volume and ocular motility. However, challenges remain, including traumatic fat atrophy and fibrosis. PMID:26889349

  9. Rapid prototyped patient specific implants for reconstruction of orbital wall defects.

    PubMed

    Stoor, Patricia; Suomalainen, Anni; Lindqvist, Christian; Mesimäki, Karri; Danielsson, Daniel; Westermark, Anders; Kontio, Risto K

    2014-12-01

    Defects of orbital walls can be reconstructed using implants. The authors report a safe and accurate method to reconstruct bone defects in the orbital area using patient specific implants. A detailed process description of computer aided design (CAD) reconstructive surgery (CRS) is introduced in this prospective study. The 3D volumetric virtual implant was design using MSCT data and PTCProEngineer™ 3D software. The intact orbital cavity of twelve patients was mirrored to the injured side. Specific ledges steered the implant into correct place. Postoperatively the position was assessed using image fusion. One implant (8%) was rejected due to chemical impurities, two (16%) had a false shape due to incorrect CAD. Data of thin bone did not transfer correctly to CAD and resulted in error. One implant (8%) was placed incorrectly. Duration of the CRS was in average 1.17 h, correspondingly 1.57 h using intraoperative bending technique. The CRS process has several critical stages, which are related to converting data and to incompatibility between software. The CRS process has several steps that need further studies. The data of thin bone may be lost and disturb an otherwise very precise technique. The risk of incorporating impurities into the implant must be carefully controlled.

  10. Crystal orbital study on the double walls made of nanotubes encapsulated inside zigzag carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Qiao, Weiye; Li, Yuliang; Huang, Yuanhe

    2015-01-01

    The structure stabilities and electronic properties are investigated by using ab initio self-consistent-field crystal orbital method based on density functional theory for the one-dimensional (1D) double-wall nanotubes made of n-gon SiO2 nanotubes encapsulated inside zigzag carbon nanotubes. It is found that formation of the combined systems is energetically favorable when the distance between the two constituents is around the Van der Waals scope. The obtained band structures show that all the combined systems are semiconductors with nonzero energy gaps. The frontier energy bands (the highest occupied band and the lowest unoccupied band) of double-wall nanotubes are mainly derived from the corresponding carbon nanotubes. The mobilities of charge carriers are calculated to be within the range of 102-104 cm2 V-1 s-1 for the hybrid double-wall nanotubes. Young's moduli are also calculated for the combined systems. For the comparison, geometrical and electronic properties of n-gon SiO2 nanotubes are also calculated and discussed.

  11. Examination Under Anesthesia for Posterior Wall Acetabular Fracture A Survey of the OTA Membership.

    PubMed

    Riehl, John; Koval, Kenneth; Langford, Joshua; Munro, Mark; Haidukewych, George

    2016-06-01

    The purpose of this survey was to learn more about the indications, criteria, and methods surgeons use for performing examination under anesthesia (EUA) for "intermediate" sized posterior wall acetabular fractures (those involving 20% to 40% of the posterior wall) and to find what criteria are used to determine hip instability. An 18 question survey was posted on the Ortho- paedic Trauma Association's website and was used to gather anonymous data from orthopaedic surgeons regarding their approach to the intermediate sized posterior wall fracture. Considerable variability existed among re- sponses to many of the questions asked. Based on the an - swers given to the survey, a consensus of 75% or more of respondents was found for the following: 1. Supine position for the examination (100%); 2. "Live" fluoroscopy is used during the examination (97%); 3. The AP and obturator oblique are the x-rays most frequently used (81% and 76%, respectively); 4. The hip is placed in flexion and adduction during the exam (100% and 84%, respectively); 5. Axial load is applied during the examination (90%); Finally, 6. instabil - ity is defined as subluxation on exam by most respondents (98%), and any perceived visible subluxation is what defines instability (88%). Most surgeons agreed with the following: 1. Supine is the position of choice for the examination; 2. "Live" fluoroscopy is used during the examination; 3. The AP and obturator oblique are the x-rays most frequently used; 4. The hip is placed in flexion and adduction during the exam; 5. Axial load is applied during the examination; and 6. Instability is defined as subluxation on exam.

  12. Crystal orbital study on the double walls made of nanotubes encapsulated inside zigzag carbon nanotubes

    SciTech Connect

    Zhao, Xin; Qiao, Weiye; Li, Yuliang; Huang, Yuanhe

    2015-01-15

    The structure stabilities and electronic properties are investigated by using ab initio self-consistent-field crystal orbital method based on density functional theory for the one-dimensional (1D) double-wall nanotubes made of n-gon SiO{sub 2} nanotubes encapsulated inside zigzag carbon nanotubes. It is found that formation of the combined systems is energetically favorable when the distance between the two constituents is around the Van der Waals scope. The obtained band structures show that all the combined systems are semiconductors with nonzero energy gaps. The frontier energy bands (the highest occupied band and the lowest unoccupied band) of double-wall nanotubes are mainly derived from the corresponding carbon nanotubes. The mobilities of charge carriers are calculated to be within the range of 10{sup 2}–10{sup 4} cm{sup 2} V{sup −1} s{sup −1} for the hybrid double-wall nanotubes. Young’s moduli are also calculated for the combined systems. For the comparison, geometrical and electronic properties of n-gon SiO{sub 2} nanotubes are also calculated and discussed. - Graphical abstract: Structures and band structures of the optimum 1D Double walls nanotubes. The optimized structures are 3-gon SiO2@(15,0), 5-gon SiO2@(17,0), 6-gon SiO2@(18,0) and 7-gon SiO2@(19,0). - Highlights: • The structure and electronic properties of the 1D n-gon SiO{sub 2}@(m,0)s are studied using SCF-CO method. • The encapsulation of 1D n-gon SiO{sub 2} tubes inside zigzag carbon nanotubes can be energetically favorable. • The 1D n-gon SiO{sub 2}@(m,0)s are all semiconductors. • The mobility of charge carriers and Young’s moduli are calculated.

  13. Evaluation of Three Cases Using a Novel Titanium Mesh System-Skull-Fit with Orbital Wall (Skull-Fit WOW)-For Cranial Base Reconstructions.

    PubMed

    Hattori, Noriko; Nakajima, Hideo; Tamada, Ikkei; Sakamoto, Yoshiaki; Ohira, Takayuki; Yoshida, Kazunari; Kawase, Takeshi; Kishi, Kazuo

    2011-09-01

    Cranial base reconstructions associated with tumor resections around the orbital wall often require that both the upper and lateral orbital walls be reconstructed during a single procedure. Previously, we used titanium mesh plates that were preoperatively fabricated based on three-dimensional models. Although these plates are precise and do not increase the probability of infection, we still had to use autologous bones to reconstruct the orbital walls. Recently, we developed a new titanium mesh plate-called Skull-Fit(®)-with orbital wall (Skull-Fit WOW(®)), enabling us to reconstruct the cranial base and orbital walls without bone grafts. Here, we report on three reconstruction cases in which the novel titanium mesh-orbital wall system was used. In all three cases, the customized titanium mesh system performed satisfactorily with little, if any, complications.

  14. Evaluation of Three Cases Using a Novel Titanium Mesh System—Skull-Fit® with Orbital Wall (Skull-Fit WOW®)—For Cranial Base Reconstructions

    PubMed Central

    Hattori, Noriko; Nakajima, Hideo; Tamada, Ikkei; Sakamoto, Yoshiaki; Ohira, Takayuki; Yoshida, Kazunari; Kawase, Takeshi; Kishi, Kazuo

    2011-01-01

    Cranial base reconstructions associated with tumor resections around the orbital wall often require that both the upper and lateral orbital walls be reconstructed during a single procedure. Previously, we used titanium mesh plates that were preoperatively fabricated based on three-dimensional models. Although these plates are precise and do not increase the probability of infection, we still had to use autologous bones to reconstruct the orbital walls. Recently, we developed a new titanium mesh plate—called Skull-Fit®—with orbital wall (Skull-Fit WOW®), enabling us to reconstruct the cranial base and orbital walls without bone grafts. Here, we report on three reconstruction cases in which the novel titanium mesh-orbital wall system was used. In all three cases, the customized titanium mesh system performed satisfactorily with little, if any, complications. PMID:22451827

  15. Influence of plaque calcifications on coronary stent fracture: a numerical fatigue life analysis including cardiac wall movement.

    PubMed

    Morlacchi, Stefano; Pennati, Giancarlo; Petrini, Lorenza; Dubini, Gabriele; Migliavacca, Francesco

    2014-03-03

    Coronary stent fracture is still an unresolved issue in the field of minimally invasive cardiovascular interventions due to its high rate of incidence and uncertain clinical consequences. Recent studies, based on clinical data, proved that there are several factors which can be identified as independently responsible of coronary stent fracture. Among these, calcifications, which increase the local stiffness and heterogeneity of atherosclerotic plaques, seem to play a major role. From a mechanical point of view, stent fracture in coronary arteries is triggered by the cyclic loading of pulsatile blood pressure combined with the movement of cardiac wall. In this context, this study aims at simulating the stent expansion in a model of epicardial atherosclerotic coronary artery and correlating the effects of cyclic blood pressure and cardiac wall movement on the stent fatigue resistance. Two ideal cases of atherosclerotic plaques were modelled: the first one included a localised plaque calcification; the latter one did not include such calcification. Results of stress/strain and fatigue analyses confirmed the influence of the plaque calcification on potential fracture of the devices. In addition, the effects of cardiac wall movement were quantified as more dangerous causes of the stent fatigue fracture with respect to the internal blood pressure oscillations. In conclusion, this study demonstrates the increased risk of coronary stent fracture associated to the presence of localised plaque calcifications. This work also suggests the necessity of more realistic biomechanical models which takes into account the heterogeneity of atherosclerotic plaques in order to assess the mechanical performances of coronary stents.

  16. Ring-shaped Racetrack memory based on spin orbit torque driven chiral domain wall motions

    PubMed Central

    Zhang, Yue; Zhang, Xueying; Hu, Jingtong; Nan, Jiang; Zheng, Zhenyi; Zhang, Zhizhong; Zhang, Youguang; Vernier, Nicolas; Ravelosona, Dafine; Zhao, Weisheng

    2016-01-01

    Racetrack memory (RM) has sparked enormous interest thanks to its outstanding potential for low-power, high-density and high-speed data storage. However, since it requires bi-directional domain wall (DW) shifting process for outputting data, the mainstream stripe-shaped concept certainly suffers from the data overflow issue. This geometrical restriction leads to increasing complexity of peripheral circuits or programming as well as undesirable reliability issue. In this work, we propose and study ring-shaped RM, which is based on an alternative mechanism, spin orbit torque (SOT) driven chiral DW motions. Micromagnetic simulations have been carried out to validate its functionality and exhibit its performance advantages. The current flowing through the heavy metal instead of ferromagnetic layer realizes the “end to end” circulation of storage data, which remains all the data in the device even if they are shifted. It blazes a promising path for application of RM in practical memory and logic. PMID:27725741

  17. Manipulation of electron orbitals in hard-wall InAs/InP nanowire quantum dots.

    PubMed

    Roddaro, Stefano; Pescaglini, Andrea; Ercolani, Daniele; Sorba, Lucia; Beltram, Fabio

    2011-04-13

    We present a novel technique for the manipulation of the energy spectrum of hard-wall InAs/InP nanowire quantum dots. By using two local gate electrodes, we induce a strong transverse electric field in the dot and demonstrate the controlled modification of its electronic orbitals. Our approach allows us to dramatically enhance the single-particle energy spacing between the first two quantum levels in the dot and thus to increment the working temperature of our InAs/InP single-electron transistors. Our devices display a very robust modulation of the conductance even at liquid nitrogen temperature, while allowing an ultimate control of the electron filling down to the last free carrier. Potential further applications of the technique to time-resolved spin manipulation are also discussed.

  18. Ring-shaped Racetrack memory based on spin orbit torque driven chiral domain wall motions

    NASA Astrophysics Data System (ADS)

    Zhang, Yue; Zhang, Xueying; Hu, Jingtong; Nan, Jiang; Zheng, Zhenyi; Zhang, Zhizhong; Zhang, Youguang; Vernier, Nicolas; Ravelosona, Dafine; Zhao, Weisheng

    2016-10-01

    Racetrack memory (RM) has sparked enormous interest thanks to its outstanding potential for low-power, high-density and high-speed data storage. However, since it requires bi-directional domain wall (DW) shifting process for outputting data, the mainstream stripe-shaped concept certainly suffers from the data overflow issue. This geometrical restriction leads to increasing complexity of peripheral circuits or programming as well as undesirable reliability issue. In this work, we propose and study ring-shaped RM, which is based on an alternative mechanism, spin orbit torque (SOT) driven chiral DW motions. Micromagnetic simulations have been carried out to validate its functionality and exhibit its performance advantages. The current flowing through the heavy metal instead of ferromagnetic layer realizes the “end to end” circulation of storage data, which remains all the data in the device even if they are shifted. It blazes a promising path for application of RM in practical memory and logic.

  19. Results after En Bloc Lateral Wall Decompression Surgery with Orbital Fat Resection in 111 Patients with Graves' Orbitopathy

    PubMed Central

    Fichter, Nicole; Guthoff, Rudolf F.

    2015-01-01

    Purpose. To evaluate the effect of en bloc lateral wall decompression with additional orbital fat resection in terms of exophthalmos reduction and complications. Methods. A retrospective, noncomparative case series study from 1999 to 2011 (chart review) in Graves' orbitopathy (GO) patients. The standardized surgical technique involved removal of the lateral orbital wall including the orbital rim via a lid crease approach combined with additional orbital fat resection. Exophthalmos, diplopia, retrobulbar pressure sensation, and complications were analyzed pre- and postoperatively. Results. A total of 111 patients (164 orbits) with follow-up >3 months were analysed. Mean exophthalmos reduction was 3.05mm and preoperative orbital pressure sensation resolved or improved in all patients. Visual acuity improved significantly in patients undergoing surgery for rehabilitative or vision threatening purposes. Preoperative diplopia improved in 10 patients (9.0%) but worsened in 5 patients (4.5%), necessitating surgical correction in 3 patients. There were no significant complications; however, one patient had slight hollowing of the temporalis muscle around the scar that did not necessitate revision, and another patient with a circumscribed retraction of the scar itself underwent surgical correction. Conclusions. The study confirms the efficiency of en bloc lateral wall decompression in GO in a large series of patients, highlighting the low risk of disturbance of binocular functions and of cosmetic blemish in the temporal midface region. PMID:26221142

  20. Environmentally-controlled fracture of an overstrained A723 steel thick-walled cylinder

    NASA Astrophysics Data System (ADS)

    Underwood, J. H.; Olmstead, V. J.; Askew, J. C.; Kapusta, A. A.; Young, G. A.

    1992-08-01

    A through-wall, 1.7 m long crack grew suddenly from a notch in a 285 mm outer diameter (OD) of an A723 steel overstrained tube that was undergoing plating operations with no externally applied loads. The fracture mechanics tests and analyses and the fractography performed to characterize the cracking are described. The tube had a yield strength of 1200 MPa, fracture toughness of 150 MPavm, and a tensile residual stress at the OD of about 600 MPa. The composition was typical of an air-melt A723 steel, and the electropolishing bath, consisting of sulfuric and phosphoric acids, was held at 54 C. The bolt-loaded test for the threshold stress intensity factor for environmentally controlled cracking described by Wei and Novak was used here with two significant modifications. Some tests included only a notch with the radius matching that of the tube, and a new expression for K in terms of crack-mouth displacement was developed and used. Scanning electron microscope fractography and energy dispersive x ray spectra were used to identify crack mechanisms. Results of the study include: (1) a measured threshold of hydrogen stress cracking for the material/environment below 20 MPavm; (2) da/dt versus K behavior typical of classic environmental control; and (3) an improved K/v expression for the bolt-loaded specimen and associated criteria for determining plane-strain test conditions in relation to the Irwin plastic zone.

  1. Numerical Investigation of the Effect of the Location of Critical Rock Block Fracture on Crack Evolution in a Gob-side Filling Wall

    NASA Astrophysics Data System (ADS)

    Li, Xuehua; Ju, Minghe; Yao, Qiangling; Zhou, Jian; Chong, Zhaohui

    2016-03-01

    Generation, propagation, and coalescence of the shear and tensile cracks in the gob-side filling wall are significantly affected by the location of the fracture of the critical rock block. The Universal Discrete Element Code software was used to investigate crack evolution characteristics in a gob-side filling wall and the parameter calibration process for various strata and the filling wall was clearly illustrated. The cracks in both the filling wall and the coal wall propagate inward in a V-shape pattern with dominant shear cracks generated initially. As the distance between the fracture and the filling wall decreases, the number of cracks in the filling wall decreases, and the stability of the filling wall gradually improves; thus, by splitting the roof rock at the optimal location, the filling wall can be maintained in a stable state. Additionally, we conducted a sensitivity analysis that demonstrated that the higher the coal seam strength, the fewer cracks occur in both the filling wall and the coal wall, and the less failure they experience. With the main roof fracturing into a cantilever structure, the higher the immediate roof strength, the fewer cracks are in the filling wall. With the critical rock block fracturing above the roadway, an optimal strength of the immediate roof can be found that will stabilize the filling wall. This study presents a theoretical investigation into stabilization of the filling wall, demonstrating the significance of pre-splitting the roof rock at a desirable location.

  2. Retroseptal Transconjunctival Approach for Blowout Fracture of the Orbital Floor: An Ideal Choice in East-Asian Patients

    PubMed Central

    Chuman, Takahiro; Fujii, Tatsuya; Morikawa, Aya; Kikuchi, Mamoru; Watanabe, Hidetaka

    2016-01-01

    Objective: To ask experts in the field to evaluate a surgeon’s experience with a retroseptal transconjunctival approach for the repair of the orbital floor damaged by blowout fracture that the surgeon encountered in 12 East-Asian patients. Methods: Patients were identified from a database, and a retrospective case note review was conducted. A total of 12 conjunctival procedures were conducted for the repair of blowout fracture with no other complicating fractures. All operative procedures were done by transconjunctival approach alone without lateral canthotomy or any other additional approach. Results: The repair of the orbital floor was successful in all the cases. Three patients had bone grafting to the orbital floor after reduction. The mean of overall surgical time was 48.8 minutes (range, 22–85 minutes) for orbit exposure by transconjunctival approach plus reduction and bone grafting when applicable. There were 6 urgent surgeries associated with missing or entrapment of the inferior rectus muscle, and its repair took an average of 32.0 minutes (range, 22–41 minutes). Postoperative diplopia recovered at an average of 12.4 weeks (range, 0–60 weeks); in urgent cases, it took an average of 5.3 weeks (range, 0–14 weeks) before recovery. Conclusions: A retroseptal transconjunctival approach in repairing the orbital floor is a simple, easily manageable, and effective procedure, leaving no conspicuous facial scars. It has proved to be an optimal choice in blowout fracture cases, especially when there was urgency to decompress the ischemic inferior rectus muscle in as short a surgery time as possible. PMID:27579249

  3. Retroseptal Transconjunctival Approach for Blowout Fracture of the Orbital Floor: An Ideal Choice in East-Asian Patients.

    PubMed

    Uemura, Tetsuji; Chuman, Takahiro; Fujii, Tatsuya; Morikawa, Aya; Kikuchi, Mamoru; Watanabe, Hidetaka

    2016-05-01

    To ask experts in the field to evaluate a surgeon's experience with a retroseptal transconjunctival approach for the repair of the orbital floor damaged by blowout fracture that the surgeon encountered in 12 East-Asian patients. Patients were identified from a database, and a retrospective case note review was conducted. A total of 12 conjunctival procedures were conducted for the repair of blowout fracture with no other complicating fractures. All operative procedures were done by transconjunctival approach alone without lateral canthotomy or any other additional approach. The repair of the orbital floor was successful in all the cases. Three patients had bone grafting to the orbital floor after reduction. The mean of overall surgical time was 48.8 minutes (range, 22-85 minutes) for orbit exposure by transconjunctival approach plus reduction and bone grafting when applicable. There were 6 urgent surgeries associated with missing or entrapment of the inferior rectus muscle, and its repair took an average of 32.0 minutes (range, 22-41 minutes). Postoperative diplopia recovered at an average of 12.4 weeks (range, 0-60 weeks); in urgent cases, it took an average of 5.3 weeks (range, 0-14 weeks) before recovery. A retroseptal transconjunctival approach in repairing the orbital floor is a simple, easily manageable, and effective procedure, leaving no conspicuous facial scars. It has proved to be an optimal choice in blowout fracture cases, especially when there was urgency to decompress the ischemic inferior rectus muscle in as short a surgery time as possible.

  4. Fracture resistance of welded thick-walled high-pressure vessels in power plants. Report No. 1. Statistical analysis of defects and fracture resistance of vessel materials

    SciTech Connect

    Gorynin, I.V.; Filatov, V.M.; Ignatov, V.A.; Timofeev, B.T.; Zvezdin, Yu. I.

    1986-07-01

    Data from plant radiographic inspection of reactor vessels and boilers in power plants of 440- and 1000-MW capacity were subjected to statistical analysis. It was found that, given the current technology for making and constructing 440- and 1000-MW power plants, the limiting defect size in the vessels of the plants is no more than 10% of the wall thickness according to the results of statistical analysis. This finding makes it possible to increase the tolerable stresses by a factor of 1.6 compared to the current estimate of resistance to brittle fracture, which presumes the presence of a semielliptical surface crack of a depth corresponding to 25% of the wall thickness. The fracture resistance of steel increase with a decrease in defect size and as a result of the damping capacity of the anticorrosive hardfacing applied.

  5. The application and progress of high-density porous polyethylene in the repair of orbital wall defect.

    PubMed

    Qian, Zhuyun; Fan, Xianqun

    2014-07-01

    High-density porous polyethylene is a type of polymeric biomaterial. When used to efficiently fill the extensive orbital volume and correct enophthalmos caused by orbital wall defect, it has a significant advantage of biocompatibility, which results in a low rate of postoperative exposure and infection. The major disadvantage of this material is its radiolucency. However, with the development of imaging techniques, it is now possible to use multidetector computed tomography to directly contour the implant and describe its position. The use of tissue engineering involving high-density porous polyethylene will further improve its biocompatibility. At the same time, composite materials will play an important role in the repair of orbital wall defect.

  6. Surgical management of temple-related problems following lateral wall rim-sparing orbital decompression for thyroid-related orbitopathy.

    PubMed

    Siah, We Fong; Patel, Bhupendra Ck; Malhotra, Raman

    2016-08-01

    To report a case series of patients with persistent temple-related problems following lateral wall rim-sparing (LWRS) orbital decompression for thyroid-related orbitopathy and to discuss their management. Retrospective review of medical records of patients referred to two oculoplastic centres (Corneoplastic Unit, Queen Victoria Hospital, East Grinstead, UK and Moran Eye Center, University of Utah, Salt Lake City, USA) for intervention to improve/alleviate temple-related problems. All patients were seeking treatment for their persistent, temple-related problems of minimum 3 years' duration post decompression. The main outcome measure was the resolution or improvement of temple-related problems. Eleven orbits of six patients (five females) with a median age of 57 years (range 23-65) were included in this study. Temple-related problems consisted of cosmetically bothersome temple hollowness (n=11; 100%), masticatory oscillopsia (n=8; 73%), temple tenderness (n=4; 36%), 'clicking' sensation (n=4; 36%) and gaze-evoked ocular pain (n=4; 36%). Nine orbits were also complicated by proptosis and exposure keratopathy. Preoperative imaging studies showed the absence of lateral wall in all 11 orbits and evidence of prolapsed lacrimal gland into the wall defect in four orbits. Intervention included the repair of the lateral wall defect with a sheet implant, orbital decompression involving fat, the medial wall or orbital floor and autologous fat transfer or synthetic filler for temple hollowness. Postoperatively, there was full resolution of masticatory oscillation, temple tenderness, 'clicking' sensation and gaze-evoked ocular pain, and an improvement in temple hollowness. Pre-existing diplopia in one patient resolved after surgery while two patients developed new-onset diplopia necessitating strabismus surgery. This is the first paper to show that persistent, troublesome temple-related problems following LWRS orbital decompression can be surgically corrected. Patients

  7. Novel use of an aerospace selective laser sintering machine for rapid prototyping of an orbital blowout fracture.

    PubMed

    Williams, J V; Revington, P J

    2010-02-01

    The authors describe the novel use of a selective laser sintering (SLS) machine, commonly used in the aerospace industry, to produce an accurate model of an orbital blowout fracture. Standard stereolithographic apparatus (SLA) technology failed to reproduce either orbital floor of a patient with a blowout fracture. The use of SLS technology using the same CT dataset to produce a superior model, highlights potential limitations of routine SLA technology and the high accuracy of SLS models. A custom-made titanium implant was constructed by hand using the SLS model as a template, it was positioned surgically and the patient's symptoms resolved uneventfully. Copyright 2009 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  8. Spin-orbit torques for current parallel and perpendicular to a domain wall

    SciTech Connect

    Schulz, Tomek; Lee, Kyujoon; Karnad, Gurucharan V.; Alejos, Oscar; Martinez, Eduardo; Moretti, Simone; Garcia, Karin; Ravelosona, Dafiné; Vila, Laurent; Lo Conte, Roberto; Kläui, Mathias; Ocker, Berthold; Brataas, Arne

    2015-09-21

    We report field- and current-induced domain wall (DW) depinning experiments in Ta\\Co{sub 20}Fe{sub 60}B{sub 20}\\MgO nanowires through a Hall cross geometry. While purely field-induced depinning shows no angular dependence on in-plane fields, the effect of the current depends crucially on the internal DW structure, which we manipulate by an external magnetic in-plane field. We show depinning measurements for a current sent parallel to the DW and compare its depinning efficiency with the conventional case of current flowing perpendicularly to the DW. We find that the maximum efficiency is similar for both current directions within the error bars, which is in line with a dominating damping-like spin-orbit torque (SOT) and indicates that no large additional torques arise for currents perpendicular to the DW. Finally, we find a varying dependence of the maximum depinning efficiency angle for different DWs and pinning levels. This emphasizes the importance of our full angular scans compared with previously used measurements for just two field directions (parallel and perpendicular to the DW) to determine the real torque strength and shows the sensitivity of the SOT to the precise DW structure and pinning sites.

  9. Posttraumatic orbital emphysema: a numerical model.

    PubMed

    Skorek, Andrzej; Kłosowski, Paweł; Plichta, Lukasz; Raczyńska, Dorota; Zmuda Trzebiatowski, Marcin; Lemski, Paweł

    2014-01-01

    Orbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture) of the deformations of the inferior orbital wall after a strike in its lower rim. Authors created a computer numeric model of the orbit with specified features-thickness and resilience modulus. During simulation an evenly spread 14400 N force was applied to the nodular points in the inferior rim (the maximal value not causing cracking of the outer rim, but only ruptures in the inferior wall). The observation was made from 1 · 10(-3) to 1 · 10(-2) second after a strike. Right after a strike dislocations of the inferior orbital wall toward the maxillary sinus were observed. Afterwards a retrograde wave of the dislocation of the inferior wall toward the orbit was noticed. Overall dislocation amplitude reached about 6 mm. Based on a numeric model of the orbit submitted to a strike in the inferior wall an existence of a retrograde shock wave causing orbital emphysema has been found.

  10. Posttraumatic Orbital Emphysema: A Numerical Model

    PubMed Central

    Skorek, Andrzej; Kłosowski, Paweł; Plichta, Łukasz; Zmuda Trzebiatowski, Marcin; Lemski, Paweł

    2014-01-01

    Orbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture) of the deformations of the inferior orbital wall after a strike in its lower rim. Authors created a computer numeric model of the orbit with specified features—thickness and resilience modulus. During simulation an evenly spread 14400 N force was applied to the nodular points in the inferior rim (the maximal value not causing cracking of the outer rim, but only ruptures in the inferior wall). The observation was made from 1 · 10−3 to 1 · 10−2 second after a strike. Right after a strike dislocations of the inferior orbital wall toward the maxillary sinus were observed. Afterwards a retrograde wave of the dislocation of the inferior wall toward the orbit was noticed. Overall dislocation amplitude reached about 6 mm. Based on a numeric model of the orbit submitted to a strike in the inferior wall an existence of a retrograde shock wave causing orbital emphysema has been found. PMID:25309749

  11. Clinical Effect of a Mixed Solution of Sodium Hyaluronate and Sodium Carboxymethylcellulose During the Transconjunctival Approach for Orbital Wall Reconstruction

    PubMed Central

    Kang, Byung Wan; Lee, Hyo Seok; Oh, Han Jin

    2012-01-01

    This study aimed to evaluate the anti-adhesive effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HACMC, Guardix-sol®) during the transconjunctival approach to orbital wall reconstruction. Eighty-seven patients who underwent orbital wall reconstruction by the transconjunctival approach were enrolled in this prospective study. We applied HACMC between the orbicularis oculi muscle and the orbital septum after surgery in 47 patients and did not use it in 40 patients. Lower lid retraction and marginal reflex distance 2 (MRD2) were measured to analyze the degree of postoperative adhesion at 1 week and 1, 3, and 6 months. The degree of MRD2 showed clinically significant differences at postoperative 1 week and 1 month between the HACMC and control groups (p<0.05). Lower lid ectropion developed in two patients (5.0%) in the control group but did not occur in the HACMC group. In orbital wall reconstruction by the transconjunctival approach, the HACMC mixture solution is effective for preventing adhesion and lower lid ectropion during the early postoperative period. PMID:22977754

  12. Clinical effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose during the transconjunctival approach for orbital wall reconstruction.

    PubMed

    Kang, Byung Wan; Lee, Hyo Seok; Oh, Han Jin; Yoon, Kyung Chul

    2012-08-01

    This study aimed to evaluate the anti-adhesive effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HACMC, Guardix-sol®) during the transconjunctival approach to orbital wall reconstruction. Eighty-seven patients who underwent orbital wall reconstruction by the transconjunctival approach were enrolled in this prospective study. We applied HACMC between the orbicularis oculi muscle and the orbital septum after surgery in 47 patients and did not use it in 40 patients. Lower lid retraction and marginal reflex distance 2 (MRD(2)) were measured to analyze the degree of postoperative adhesion at 1 week and 1, 3, and 6 months. The degree of MRD(2) showed clinically significant differences at postoperative 1 week and 1 month between the HACMC and control groups (p<0.05). Lower lid ectropion developed in two patients (5.0%) in the control group but did not occur in the HACMC group. In orbital wall reconstruction by the transconjunctival approach, the HACMC mixture solution is effective for preventing adhesion and lower lid ectropion during the early postoperative period.

  13. Application of Computer-Aided Designing and Rapid Prototyping Technologies in Reconstruction of Blowout Fractures of the Orbital Floor.

    PubMed

    Tabaković, Saša Z; Konstantinović, Vitomir S; Radosavljević, Radivoje; Movrin, Dejan; Hadžistević, Miodrag; Hatab, Nur

    2015-07-01

    Traumatology of the maxillofacial region represents a wide range of different types of facial skeletal injuries and encompasses numerous treatment methods. Application of computer-aided design (CAD) in combination with rapid prototyping (RP) technologies and three-dimensional computed tomography techniques facilitates surgical therapy planning for efficient treatment. The purpose of this study is to determine the efficiency of individually designed implants of poly-DL-lactide (PDLLA) in the reconstruction of blowout fractures of the orbital floor. In the course of a surgical treatment, individually designed implants manufactured by CAD/RP technologies were used. Preoperative analysis and postoperative monitoring were conducted to evaluate the successfulness of orbital floor reconstruction using customized PDLLA implants, based on: presence of diplopia, paresthesia of infraorbital nerve, and presence of enophthalmos. In 6 of the 10 patients, diplopia completely disappeared immediately after surgical procedure. Diplopia gradually disappeared after 1 month in 3 patients, whereas in 1, it remained even after 6 months. In 7 patients, paresthesia disappeared within a month after surgery and in 3 patients within 2 months. Postoperative average Orbital volume (OV) of the injured side (13.333 ± 3.177) was significantly reduced in comparison with preoperative OV (15.847 ± 3.361) after reconstruction of the orbital floor with customized PDLLA implant (P < 0.001). Thus, average OV of corrected orbit was not different compared with the OV of the uninjured orbit (P = 0.981). Reconstruction of blowout fractures of the orbital floor by an individually designed PDLLA implant combined with virtual preoperative modeling allows easier preoperative preparation and yields satisfactory functional and esthetic outcomes.

  14. Computer-assisted analysis of anatomical relationships of the ethmoidal foramina and optic canal along the medial orbital wall.

    PubMed

    Celik, Servet; Ozer, Mehmet Asim; Kazak, Zuhal; Govsa, Figen

    2015-11-01

    Typically, the medial orbital wall contains an anterior ethmoidal foramen (EF) and a posterior EF, but may also have multiple EFs transmitting the arteries and nerves between the orbit and the anterior cranial fossa. The aim of this study is to determine a patient-friendly landmark of the medial orbital wall and to specify a precise location of the ethmoidal foramens (EF) in order to standardize certain anatomical marks as safe ethmoidal arteries. Orientation points on the anterior ethmoidal foramen (AEF), posterior ethmoidal foramen (PEF) and middle ethmoidal foramen (MEF) were investigated in 262 orbits. Using a software program, distances between each foramen and the midpoint of the anterior lacrimal crest (ALC), the optic canal (OC), and some important angles were measured. The EFs were identified as single in 0.8%, double in 73.7%, triple 24,4% and quadruple in 1.1% specimens. The mean distances between ALC and AEF, ALC and PEF and ALC and MEF were 27.7, 10.6, and 12.95 mm, respectively. The distances from ALC-AEF, AEF-PEF, and PEF-OC were 27.7 ± 2.8, 10.6 ± 3.3, 5.4 ± 1 mm. The angles from the plane of the EF to the medial border of the OC were calculated as 13.2° and 153°, respectively. The angle from the AEF to the medial border of the OC was based on the plane between the ALC and AEF was 132°. The occurrence of multiple EF with an incidence of 25% narrows the borders of the safe region in the medial orbital wall. Safe distance of the ALC-EF was measured as 22.1 mm on medial wall. The line of the location of the EF was calculated 16.2 mm. In this study, it was possible to investigate the variability of the orbital orifice of the EF and the feasibility of the EA, to observe various angles of the orbital wall bones and to calculate the lengths of some parameters with the help of certain software.

  15. The history of the walls of the Acropolis of Athens and the natural history of secondary fracture healing process.

    PubMed

    Lyritis, G P

    2000-09-01

    During its long and adventurous history, the Acropolis of Athens has been a site of many dramatic events. It suffered its most disastrous destruction during the Persian wars. Under the command of King Xerxes, the Persians invaded Athens and ruined the Temple of the Parthenon and the walls of the Acropolis. After their victorious sea battle at Salamis, the Athenians, led by Themistocles, returned home and tried to repair the damage. Their priority still was to defend their city by restoring the walls of the Acropolis. Materials of all kinds were salvaged from the ruins of the Acropolis and used for an immediate reconstruction of the walls. Later, when the Athenians became the leaders of the Greek world, it was decided that the walls should be rebuilt in a proper artistic way. Themistocles suggested that a small section of the walls, which had formerly been a part of the urgent restoration, should remain in place so as to remind the citizens of this historical event. This is a characteristic example of the biological and mechanical adaptation of fracture callus to musculoskeletal function. After a period of urgency with the fixation of a fracture by means of a primitive secondary callus formation, the broken limb gradually returns to its usual function. Increased mechanical loading enhances the remodelling of the callus and the replacement of woven bone with lamellar bone.

  16. Influence of irrigant, dowel type, and root-reinforcing material on fracture resistance of thin-walled endodontically treated teeth.

    PubMed

    Ayad, Mohamed F; Bahannan, Salma A; Rosenstiel, Stephen F

    2011-04-01

    Unresolved controversy exists concerning the optimum restorative material to reinforce the thin-walled roots of endodontically treated teeth to improve their fracture resistance under occlusal load. This study evaluated the effectiveness of irrigant, dowel type, and root-reinforcing material on the fracture resistance of thin-walled endodontically treated teeth. The root canals of 140 maxillary central incisors were enlarged and equally divided into seven groups according to the canal irrigant: no irrigant (control), 5% hydrogen peroxide, 5% sodium hypochlorite, a combination of 5% hydrogen peroxide and sodium hypochlorite, 15% ethylenediaminotetraacetic acid (EDTA), 10% lactic acid, or 20% lactic acid. Within each group, root canals were lined with composite resin (PermaFlo) or glass ionomer cement (Fuji II LC). A light-transmitting plastic dowel (Luminex) was used to create space for a quartz fiber-reinforced dowel (Aestheti Post) or a titanium alloy dowel (ParaPost XH) and to cure the restorative materials. Following dowel cementation and restoration of the roots with composite core, the teeth were submitted to fracture resistance testing, and data were analyzed with 3-way ANOVA followed by Ryan-Einot-Gabriel-Welsch Multiple Range Test (α= 0.05). Fracture resistance values were significantly different among irrigants, restorative materials, and their interaction (p < 0.001); however, the dowel type was not significantly different (p= 0.51). Thin-walled roots that had the smear layer removed with lactic acid and that were then lined with composite resin had a higher fracture resistance. © 2011 by The American College of Prosthodontists.

  17. Propensity for hip dislocation in normal gait loading versus sit-to-stand maneuvers in posterior wall acetabular fractures.

    PubMed

    Marmor, Meir; McDonald, Erik; Buckley, Jenni M; Matityahu, Amir

    2013-09-01

    Treatment of posterior wall (PW) fractures of the acetabulum is guided by the size of the broken wall fragment and by hip instability. Biomechanical testing of hip instability typically is done by simulating the single-leg-stance (SLS) phase of gait, but this does not represent daily activities, such as sit-to-stand (STS) motion. We conducted a study to examine and compare hip instability after PW fractures in SLS and STS loading. We hypothesized that wall fragment size and distance from the dome (DFD) of the acetabulum to the simulated fracture would correlate with hip instability and, in the presence of a PW fracture, the hip would be more unstable during STS loading than during SLS loading. Incremental PW osteotomies were made in 6 cadaveric acetabula. After each osteotomy, a 1200-N load was applied to the acetabulum to simulate SLS and STS loading until dislocation occurred. All hip joints in the cadaveric models were more unstable in STS loading than in SLS loading. PW fragments at time of dislocation were larger (P<.001) in SLS loading (85% ± 13%; range, 81%-100%) than in STS loading (40% ± 7%; range, 33%-52%). Mean (SD) DFD at time of dislocation was 15.0 (3.5) mm (range, 14.4-19.6 mm) in STS loading and 5.3 (4.3) mm (range, 0.1-10.0 mm) in SLS loading (P<.04). There was more hip instability in STS loading than in SLS loading. In STS loading, hips dislocated with a PW fracture size of 33% or more and a DFD of 20 mm or less.

  18. [Kocher-Langenbeck approach in the surgical management of posterior wall fractures of the acetabulum].

    PubMed

    Fernández-Palomo, L J

    2016-01-01

    Surgical treatment of acetabular fractures is indicated in displaced cases in order to restore and stabilize the hip joint and the pelvic ring integrity. Posterior structure fractures must be treated through posterior pelvic surgical approaches. The Kocher-Langenbeck is the most recommended approach for the majority of posterior acetabular fractures.

  19. Vertebroplasty in multiple myeloma with osteolysis or fracture of the posterior vertebral wall. Usefulness of a delayed cement injection.

    PubMed

    Basile, Antonio; Cavalli, Maide; Fiumara, Paolo; Di Raimondo, Francesco; Mundo, Elena; Caltabiano, Giuseppe; Arcerito, Flavio; Patti, Maria Teresa; Granata, Antonio; Tsetis, Dimitrios

    2011-07-01

    The goal of this study was to specifically address the incidence of dorsal leakage when performing vertebroplasty in patients with posterior wall osteolysis or fracture, by using a delayed injection of cement with the aim of increasing its viscosity. We prospectively reviewed the records of 24 patients (13 women, 11 men; age range 42-67 years; mean age 54.7) with diagnosis of multiple myeloma (MM) who underwent 34 vertebroplasties between January 2007 and January 2010 for painful osteolytic localization of MM with dorsal cortical osteolysis or fracture. All vertebroplasties were performed with an 8 min delay, which was half of the allotted injecting time given for the chosen cement. In 11 cases there were fractures involving the posterior wall, in 1 case with dorsal fragment dislocation, and in 33 cases there was dorsal cortical osteolysis. All of the patients showed no response to standard treatments such as radiotherapy, chemotherapy, and analgesic treatments. Technical success was achieved in all cases. In 20 patients, we treated only one high-risk vertebral lesion, in six patients we treated two segments, and in one patient we treated three segments. All patients experienced improvement in symptoms after the procedure as demonstrated by improved visual analogue scores (VAS) and performance status (PS) and decreased doses of analgesic. There was a dorsal leakage in 2/34 (5.8%) treated vertebral bodies in which an epidural space tumor extension was also diagnosed, without increasing neurological symptoms after the intervention. From these results vertebroplasty with delayed injection of cement is safe and effective in the treatment of vertebral localization of myeloma with osteolysis or fracture of the posterior vertebral wall.

  20. Secondary infection affecting one of two simultaneously placed orbital wall implants.

    PubMed

    Babar, Sonya; Iliff, Nicholas T; Macquaid, Emily

    2009-05-01

    A 10-year-old boy experienced traumatic injuries to the right bony orbit, which were repaired with a nylon foil and a barrier porous polyethylene orbital implant. Three years after surgery, he presented with maxillary and ethmoid sinusitis with infection of the nylon foil plate. This plate was removed, yielding complete recovery.

  1. Finite element analysis of the stability of combined plate internal fixation in posterior wall fractures of acetabulum

    PubMed Central

    Liu, Xi-Ming; Pan, Chang-Wu; Wang, Guo-Dong; Cai, Xian-Hua; Chen, Lei; Meng, Cheng-Fei; Huang, Jin-Cheng

    2015-01-01

    Objective: This study aims to explore the mechanical stability of combined plate internal fixation in posterior wall fractures of the acetabulum. Methods: The fracture and internal fixation models were established in this study and they were divided into four kinds of internal fixation models, finite element analysis was performed. The four groups were 2 mini-plates and 1 reconstruction plate fixation (A), Reconstruction plate internal fixation group (B), 2 screws internal fixation group (C) and mini-plates internal fixation group (D). The displacement of each node was measured and evaluated. Results: There was no distortion in the geometric shape of the finite element model. The results of stress showed that it was less in the anterior pelvic ring and distributed uniform in labrum acetabulare; the stress was bigger in the upper and middle of sacroiliac joint and sciatic notch in sitting position. Conclusions: Combined plate internal fixation for posterior wall fractures of acetabular were stable and reliable, it is better than the other three methods. PMID:26550272

  2. Virtual Surgical Planning for Orbital Reconstruction.

    PubMed

    Susarla, Srinivas M; Duncan, Katherine; Mahoney, Nicholas R; Merbs, Shannath L; Grant, Michael P

    2015-01-01

    The advent of computer-assisted technology has revolutionized planning for complex craniofacial operations, including orbital reconstruction. Orbital reconstruction is ideally suited for virtual planning, as it allows the surgeon to assess the bony anatomy and critical neurovascular structures within the orbit, and plan osteotomies, fracture reductions, and orbital implant placement with efficiency and predictability. In this article, we review the use of virtual surgical planning for orbital decompression, posttraumatic midface reconstruction, reconstruction of a two-wall orbital defect, and reconstruction of a large orbital floor defect with a custom implant. The surgeon managing orbital pathology and posttraumatic orbital deformities can benefit immensely from utilizing virtual planning for various types of orbital pathology.

  3. Virtual Surgical Planning for Orbital Reconstruction

    PubMed Central

    Susarla, Srinivas M.; Duncan, Katherine; Mahoney, Nicholas R.; Merbs, Shannath L.; Grant, Michael P.

    2015-01-01

    The advent of computer-assisted technology has revolutionized planning for complex craniofacial operations, including orbital reconstruction. Orbital reconstruction is ideally suited for virtual planning, as it allows the surgeon to assess the bony anatomy and critical neurovascular structures within the orbit, and plan osteotomies, fracture reductions, and orbital implant placement with efficiency and predictability. In this article, we review the use of virtual surgical planning for orbital decompression, posttraumatic midface reconstruction, reconstruction of a two-wall orbital defect, and reconstruction of a large orbital floor defect with a custom implant. The surgeon managing orbital pathology and posttraumatic orbital deformities can benefit immensely from utilizing virtual planning for various types of orbital pathology. PMID:26692714

  4. Does a minimal invasive approach reduce anterior chest wall numbness and postoperative pain in plate fixation of clavicle fractures?

    PubMed

    Beirer, Marc; Postl, Lukas; Crönlein, Moritz; Siebenlist, Sebastian; Huber-Wagner, Stefan; Braun, Karl F; Biberthaler, Peter; Kirchhoff, Chlodwig

    2015-05-28

    Fractures of the clavicle present very common injuries with a peak of incidence in young active patients. Recently published randomized clinical trials demonstrated an improved functional outcome and a lower rate of nonunions in comparison to non-operative treatment. Anterior chest wall numbness due to injury of the supraclavicular nerve and postoperative pain constitute common surgery related complications in plate fixation of displaced clavicle fractures. We recently developed a technique for mini open plating (MOP) of the clavicle to reduce postoperative numbness and pain. The purpose of this study was to analyze the size of anterior chest wall numbness and the intensity of postoperative pain in MOP in comparison to conventional open plating (COP) of clavicle fractures. 24 patients (mean age 38.2 ± 14.2 yrs.) with a displaced fracture of the clavicle (Orthopaedic Trauma Association B1.2-C1.2) surgically treated using a locking compression plate (LCP) were enrolled. 12 patients underwent MOP and another 12 patients COP. Anterior chest wall numbness was measured with a transparency grid on the second postoperative day and at the six months follow-up. Postoperative pain was evaluated using the Visual Analog Scale (VAS). Mean ratio of skin incision length to plate length was 0.61 ± 0.04 in the MOP group and 0.85 ± 0.06 in the COP group (p < 0.05). Mean ratio of the area of anterior chest wall numbness to plate length was postoperative 7.6 ± 5.9 (six months follow-up 4.7 ± 3.9) in the MOP group and 22.1 ± 19.1 (16.9 ± 14.1) in the COP group (p < 0.05). Mean VAS was 2.6 ± 1.4 points in the MOP group and 3.4 ± 1.6 points in the COP group (p = 0.20). In our study, MOP significantly reduced anterior chest wall numbness in comparison to a conventional open approach postoperative as well as at the six months follow-up. Postoperative pain tended to be lower in the MOP group, however this difference was not statistically significant. ClinicalTrials.gov NCT02247778

  5. Previously undescribed palpebral branch from the infraorbital canal: Application to surgery of the eyelid and treatment of orbital floor fractures.

    PubMed

    Iwanaga, Joe; Watanabe, Koichi; Oskouian, Rod J; Tubbs, R Shane

    2017-09-01

    The sensory innervation of the inferior eyelid is mainly derived from the inferior palpebral branch (IPb) of the infraorbital nerve (ION). This study aimed to investigate another, to our knowledge, previously unknown branch, and elucidate its location and distribution. Twelve sides from seven fresh frozen cadaveric Caucasian heads were used in this study. The specimens were derived from two male and four female adult cadavers age. The diameter of the IPb of the ION (D1) and branch arising from the upper wall of the infraorbital canal (D2), and distance between the branching points of this branch and the anterior border of the orbit floor (L1) was measured. A branch to the lower eyelid was found arising from the infraorbital canal on the majority of sides. D1 ranged from 0.4 to 1.1 mm. The branch arising from the upper wall of the infraorbital canal was found 10 sides (83%). D2 ranged 0.6 to 1.0 mm. L1 ranged from 10.2 to 19.8 mm. All of the branches arising from the upper wall of the infraorbital canal (10 sides) primarily innervated to the inferior eyelid. We suggest this branch should be named the "posterior IPb" of the ION. Knowledge of this branch might decrease sensory loss following invasive procedures of the lower orbit. Clin. Anat. 30:835-838, 2017. © 2017Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  6. Orbital

    NASA Astrophysics Data System (ADS)

    Hanson, Robert M.

    2003-06-01

    ORBITAL requires the following software, which is available for free download from the Internet: Netscape Navigator, version 4.75 or higher, or Microsoft Internet Explorer, version 5.0 or higher; Chime Plug-in, version compatible with your OS and browser (available from MDL).

  7. Numerical Simulation of Impact Damage Induced by Orbital Debris on Shielded Wall of Composite Overwrapped Pressure Vessel

    NASA Astrophysics Data System (ADS)

    Cherniaev, Aleksandr; Telichev, Igor

    2014-12-01

    This paper presents a methodology for numerical simulation of the formation of the front wall damage in composite overwrapped pressure vessels under hypervelocity impact. Both SPH particles and Lagrangian finite elements were employed in combination for numerical simulations. Detailed numerical models implementing two filament winding patterns with different degree of interweaving were developed and used to simulate 2.5 km/s and 5.0 km/s impacts of 5 mm-diameter spherical aluminum-alloy projectile. Obtained results indicate that winding pattern may have a pronounced effect on vessel damage in case of orbital debris impact, influencing propagation of the stress waves in composite material.

  8. Surgical Outcomes of Balanced Deep Lateral and Medial Orbital Wall Decompression in Korean Population: Clinical and Computed Tomography-based Analysis

    PubMed Central

    Choi, Sang Uk; Kim, Kyoung Woo

    2016-01-01

    Purpose To evaluate the clinical outcomes of balanced deep lateral and medial orbital wall decompression and to estimate surgical effects using computed tomography (CT) images in Korean patients with thyroid-associated ophthalmopathy (TAO). Methods Retrospective chart review was conducted in TAO patients with exophthalmos who underwent balanced deep lateral and medial orbital wall decompression. Exophthalmos was measured preoperatively and postoperatively at 1 and 3 months. Postoperative complications were evaluated in all study periods. In addition, decompressed bone volume was estimated using CT images. Thereafter, decompression volume in each decompressed orbital wall was analyzed to evaluate the surgical effect and predictability. Results Twenty-four patients (48 orbits) with an average age of 34.08 ± 7.03 years were evaluated. The mean preoperative and postoperative exophthalmos at 1 and 3 months was 18.91 ± 1.43, 15.10 ± 1.53, and 14.91 ± 1.49 mm, respectively. Bony decompression volume was 0.80 ± 0.29 cm3 at the medial wall and 0.68 ± 0.23 cm3 at the deep lateral wall. Postoperative complications included strabismus (one patient, 2.08%), upper eyelid fold change (four patients, 8.33%), and dysesthesia (four patients, 8.33%). Postsurgical exophthalmos reduction was more highly correlated with the deep lateral wall than the medial wall. Conclusions In TAO patients with exophthalmos, balanced deep lateral and medial orbital wall decompression is a good surgical method with a low-risk of complications. In addition, deep lateral wall decompression has higher surgical predictability than medial wall decompression, as seen with CT analysis. PMID:27051255

  9. Diagnosis and surgical treatment of defects in the wall of the orbit of children and adults using demineralized bone allografts.

    PubMed

    Ryabov, Alexey; Lekishvili, Mikhail

    2016-09-01

    Accuracy of diagnosis defines the quality of treatment in patients with traumatic damage to eyelet walls. In this area, complex functional and anatomical breaches are typical and require full characterization of pathological changes in bone and soft tissue structures. A new plastic material with a high degree level of demineralization called "Perfoost" can be used to treat defects in the bones of the face of children and adults. In the present study, 79 patients with fractured eyelet walls were treated between 1999 and 2006 by grafting the defect wall with demineralized bone allografts. Grafts were applied from 2 days to 18 months after trauma. Magnetic resonance computer CT was used to check the realignment of allografts every 6 months after the reconstructive operation. The post-operative period of the observation was from 6 months to 7 years after the operation. Good or satisfactory results were obtained for 97.47 % of patients.

  10. Reconstruction of orbital floor blow-out fractures with autogenous iliac crest bone: a retrospective study including maxillofacial and ophthalmology perspectives.

    PubMed

    O'Connell, John Edward; Hartnett, Claire; Hickey-Dwyer, Marie; Kearns, Gerard J

    2015-03-01

    This is a 10-year retrospective study of patients with an isolated unilateral orbital floor fracture reconstructed with an autogenous iliac crest bone graft. The following inclusion criteria applied: isolated orbital floor fracture without involvement of the orbital rim or other craniofacial injuries, pre-/post-operative ophthalmological/orthoptic follow-up, pre-operative CT. Variables recorded were patient age and gender, aetiology of injury, time to surgery, follow-up period, surgical morbidity, diplopia pre- and post-operatively (Hess test), eyelid position, visual acuity, and the presence of en-/or exophthalmos (Hertel exophthalmometer). Twenty patients met the inclusion criteria. The mean age was 29 years. The mean follow up period was 26 months. No patient experienced significant donor site morbidity. There were no episodes of post-operative infection or graft extrusion. Three patients had diplopia in extremes of vision post-operatively, but no interference with activities of daily living. One patient had post-operative enophthalmos. Isolated orbital blow-out fractures may be safely and predictably reconstructed using autogenous iliac crest bone. The rate of complications in the group of patients studied was low. The value of pre- and post-operative ophthalmology consultation cannot be underestimated, and should be considered the standard of care in all patients with orbitozygomatic fractures, in particular those with blow-out fractures. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  11. Comparison of the supporting strength of a poly-L-lactic acid sheet and porous polyethylene (Medpor) for the reconstruction of orbital floor fractures.

    PubMed

    Hwang, Kun; Kim, Dong Hyun

    2010-05-01

    The aim of this study was to elucidate the supporting strength of the curved poly-L-lactic acid (PLLA) sheet and porous polyethylene (Medpor) for reconstruction of orbital floor fractures. For one-half and two-thirds orbital floor fractures, reconstruction was performed using the PLLA sheet and Medpor. The PLLA sheet was molded to fit the orbital floor (concavity). The anterior portion (1 cm) was curved to fit the inferior orbital rim and fixed with a screw. Medpor was designed to fit the orbital floor. A screw was fixed 6 mm away from the anterior border of the orbital floor. Each implant was hung by wire, and the degree of sagging of the implant was measured using micrometers by the power of a force gauge. For one-half orbital floor fractures, the power of the PLLA sheet to sag 5 mm was 2.46 (SD, 0.14) N, and that of Medpor was 0.59 (SD, 0.04) N. The power of the PLLA sheet to sag 10 mm was 6.9 (SD, 0.14) N, and that of Medpor was 1.52 (SD, 0.16) N. For two-thirds orbital floor fractures, the power of the PLLA sheet to sag 5 mm was 1.79 (SD, 0.24) N, and that of Medpor was 0.39 (SD, 0.04) N. For 10 mm of sagging, the power of the PLLA sheet was 5.61 (SD, 0.29) N, and that of Medpor was 0.94 (SD, 0.09) N. For sagging of 15 mm, the power of the PLLA sheet was 8.99 (SD, 0.16) N, and that of Medpor was 2.98 (SD, 0.24) N. The PLLA sheet was irreversibly bent when the force reached approximately 8 to 9 N. For Medpor, the degree of sagging during the early stage was larger than at the later stage. In all situations, the supporting power of the PLLA sheet was greater than that of Medpor. The differences were significant in all situations (P = 0.000). The degree of sagging in one-half orbital floor fractures was 2.87 mm for the PLLA sheet and 7.96 mm for Medpor. There was an increased orbital volume of 0.4 mL with the PLLA sheet and 1.19 mL for Medpor. The predicted enophthalmos was 0.41 mm with the PLLA sheet and 1.07 mm with Medpor. The degree of sagging for the two

  12. Fractures

    MedlinePlus

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

  13. Interaction of hydraulic and buckling mechanisms in blowout fractures.

    PubMed

    Nagasao, Tomohisa; Miyamoto, Junpei; Jiang, Hua; Tamaki, Tamotsu; Kaneko, Tsuyoshi

    2010-04-01

    The etiology of blowout fractures is generally attributed to 2 mechanisms--increase in the pressure of the orbital contents (the hydraulic mechanism) and direct transmission of impacts on the orbital walls (the buckling mechanism). The present study aims to elucidate whether or not an interaction exists between these 2 mechanisms. We performed a simulation experiment using 10 Computer-Aided-Design skull models. We applied destructive energy to the orbits of the 10 models in 3 different ways. First, to simulate pure hydraulic mechanism, energy was applied solely on the internal walls of the orbit. Second, to simulate pure buckling mechanism, energy was applied solely on the inferior rim of the orbit. Third, to simulate the combined effect of the hydraulic and buckling mechanisms, energy was applied both on the internal wall of the orbit and inferior rim of the orbit. After applying the energy, we calculated the areas of the regions where fracture occurred in the models. Thereafter, we compared the areas among the 3 energy application patterns. When the hydraulic and buckling mechanisms work simultaneously, fracture occurs on wider areas of the orbital walls than when each of these mechanisms works separately. The hydraulic and buckling mechanisms interact, enhancing each other's effect. This information should be taken into consideration when we examine patients in whom blowout fracture is suspected.

  14. Fracture behavior of shallow cracks in full-thickness clad beams from an RPV wall section

    SciTech Connect

    Keeney, J.A.; Bass, B.R.; McAfee, W.J.

    1995-04-01

    A testing program is described that utilizes full-thickness clad beam specimens to quantify fracture toughness for shallow cracks in weld material for which metallurgical conditions are prototypic of those found in reactor pressure vessels (RPVs). The beam specimens are fabricated from an RPV shell segment that includes weld, plate and clad material. Metallurgical factors potentially influencing fracture toughness for shallow cracks in the beam specimens include material gradients and material inhomogeneities in welded regions. The shallow-crack clad beam specimens showed a significant loss of constraint similar to that of other shallow-crack single-edge notch bend (SENB) specimens. The stress-based Dodds-Anderson scaling model appears to be effective in adjusting the test data to account for in-plane loss of constraint for uniaxially tested beams, but cannot predict the observed effects of out-of-plane biaxial loading on shallow-crack fracture toughness. A strain-based dual-parameter fracture toughness correlation (based on plastic zone width) performed acceptably when applied to the uniaxial and biaxial shallow-crack fracture toughness data.

  15. [Endoscopic approaches to the orbit].

    PubMed

    Cebula, H; Lahlou, A; De Battista, J C; Debry, C; Froelich, S

    2010-01-01

    During the last decade, the use of endoscopic endonasal approaches to the pituitary has increased considerably. The endoscopic endonasal and transantral approaches offer a minimally invasive alternative to the classic transcranial or transconjunctival approaches to the medial aspect of the orbit. The medial wall of the orbit, the orbital apex, and the optic canal can be exposed through a middle meatal antrostomy, an anterior and posterior ethmoidectomy, and a sphenoidotomy. The inferomedial wall of the orbit can be also perfectly visualized through a sublabial antrostomy or an inferior meatal antrostomy. Several reports have described the use of an endoscopic approach for the resection or the biopsy of lesions located on the medial extraconal aspect of the orbit and orbital apex. However, the resection of intraconal lesions is still limited by inadequate instrumentation. Other indications for the endoscopic approach to the orbit are the decompression of the orbit for Graves' ophthalmopathy and traumatic optic neuropathy. However, the optimal management of traumatic optic neuropathy remains very controversial. Endoscopic endonasal decompression of the optic nerve in case of tumor compression could be a more valid indication in combination with radiation therapy. Finally, the endoscopic transantral treatment of blowout fracture of the floor of the orbit is an interesting option that avoids the eyelid or conjunctive incision of traditional approaches. The collaboration between the neurosurgeon and the ENT surgeon is mandatory and reduces the morbidity of the approach. Progress in instrumentation and optical devices will certainly make this approach promising for intraconal tumor of the orbit.

  16. Subciliary vs. transconjunctival approach for the management of orbital floor and periorbital fractures: A systematic review and meta-analysis.

    PubMed

    Al-Moraissi, Essam Ahmed; Thaller, Seth R; Ellis, Edward

    2017-07-19

    This study compared complications between subciliary and transconjunctival approaches to the infraorbital rim/orbital floor, using systematic review and meta-analysis. A systematic review with meta-analysis was conducted according to PRISMA guidelines. An electronic search in PubMed, Embase, and Cochrane Library was performed. Randomized controlled and controlled (retrospective or prospective) clinical studies, with the aim of comparing subciliary to transconjunctival approaches in the management of infraorbital rim/orbital floor fractures, were included. Outcome variables were lower lid malposition including ectropion, entropion, scleral shows, canthal malpositions, and others complications. An odds ratio (OR) of outcome variables, using a Mantel-Haenszel (M-H) test with 95% confidence intervals (95% CIs), was calculated using Comprehensive Meta-analysis Software. A descriptive analysis of postoperative complications was also presented. The subciliary approach had a significantly higher incidence of ectropion and scleral show when compared with the subconjunctival approach (p < 0.001). The subconjunctival approach had a significantly higher incidence of entropion than the subciliary approach (p < 0.001). Both the subciliary and the transconjunctival approaches are associated with specific complications. Overall, the transconjunctival approach shows the lowest incidence of complications. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  17. Fracture strengths of HIPed DS-Cu/SS joints for ITER shielding blanket/first wall

    NASA Astrophysics Data System (ADS)

    Hatano, T.; Kanari, M.; Sato, S.; Gotoh, M.; Furuya, K.; Kuroda, T.; Saito, M.; Enoeda, M.; Takatsu, H.

    1998-10-01

    Fracture toughness and crack propagation tests were performed to investigate the effect of HIP temperature and fracture behavior of HIPed DS-Cu/SS joints. Test specimens of DS-Cu/SS HIPed joints were manufactured by bonding flat plates of DS-Cu and SS under HIP temperatures of 980°C, 1030°C and 1050°C. JQ of the joint at HIP temperature of 1050°C was larger than the other two joints. For the crack propagation test, two types of test specimens were prepared. One had a notch along the HIPed interface and the other in DS-Cu and normal to the interface. The crack in the former specimen propagated along the interface. On the other hand, the crack in the latter specimen propagated in the DS-Cu perpendicular to the loading direction, stopped at the interface, and then exfoliated along the HIPed interface. In the fracture tests, the crack was observed propagating in DS-Cu side at approximately 5-10 μm away from the interface.

  18. Anomalous spin-orbit torque switching due to field-like torque-assisted domain wall reflection.

    PubMed

    Yoon, Jungbum; Lee, Seo-Won; Kwon, Jae Hyun; Lee, Jong Min; Son, Jaesung; Qiu, Xuepeng; Lee, Kyung-Jin; Yang, Hyunsoo

    2017-04-01

    Spin-orbit torques (SOTs) allow the electrical control of magnetic states. Current-induced SOT switching of the perpendicular magnetization is of particular technological importance. The SOT consists of damping-like and field-like torques, and understanding the combined effects of these two torque components is required for efficient SOT switching. Previous quasi-static measurements have reported an increased switching probability with the width of current pulses, as predicted considering the damping-like torque alone. We report a decreased switching probability at longer pulse widths, based on time-resolved measurements. Micromagnetic analysis reveals that this anomalous SOT switching results from domain wall reflections at sample edges. The domain wall reflection was found to strongly depend on the field-like torque and its relative sign to the damping-like torque. Our result demonstrates a key role of the field-like torque in deterministic SOT switching and the importance of the sign correlation of the two torque components, which may shed light on the SOT switching mechanism.

  19. Failure Analysis of Fractured Poppet from Space Shuttle Orbiter Flow Control Valve

    NASA Technical Reports Server (NTRS)

    Russell, Richard

    2010-01-01

    This slide presentation reviews the failure analysis of a fractured poppet from a flow control valve (FCV) used on the space shuttle. This presentation has focused on the laboratory analysis of the failed hardware. The use of Scanning electron fractography during the investigation led to the conclusion that the poppet failed due to fatigue cracking that, most likely, occurred under changing loading conditions. The initial investigation led to a more thorough test of poppets that had been retired, this testing led to the conclusion that the thumbnail cracks in the flight hardware had existed for the life of the shuttle program. This led to a program to develop an eddy current technique that was capable of detecting small very tight cracks.

  20. Facial fractures.

    PubMed Central

    Carr, M. M.; Freiberg, A.; Martin, R. D.

    1994-01-01

    Emergency room physicians frequently see facial fractures that can have serious consequences for patients if mismanaged. This article reviews the signs, symptoms, imaging techniques, and general modes of treatment of common facial fractures. It focuses on fractures of the mandible, zygomaticomaxillary region, orbital floor, and nose. Images p520-a p522-a PMID:8199509

  1. Applications of 3D orbital computer-assisted surgery (CAS).

    PubMed

    Scolozzi, P

    2017-09-01

    The purpose of the present report is to describe the indications for use of 3D orbital computer-assisted surgery (CAS). We analyzed the clinical and radiological data of all patients with orbital deformities treated using intra-operative navigation and CAD/CAM techniques at the Hôpitaux Universitaires de Genève, Switzerland, between 2009 and 2016. We recorded age and gender, orbital deformity, technical and surgical procedure and postoperative complications. One hundred and three patients were included. Mean age was 39.5years (range, 5 to 84years) and 85 (87.5%) were men. Of the 103 patients, 96 had intra-operative navigation (34 for primary and 3 for secondary orbito-zygomatic fractures, 15 for Le Fort fractures, 16 for orbital floor fractures, 10 for combined orbital floor and medial wall fractures, 7 for orbital medial wall fractures, 3 for NOE (naso-orbito-ethmoidal) fractures, 2 for isolated comminuted zygomatic arch fractures, 1 for enophthalmos, 3 for TMJ ankylosis and 2 for fibrous dysplasia bone recontouring), 8 patients had CAD/CAM PEEK-PSI for correction of residual orbital bone contour following craniomaxillofacial trauma, and 1 patient had CAD/CAM surgical splints and cutting guides for correction of orbital hypertelorism. Two patient (1.9%) required revision surgery for readjustment of an orbital mesh. The 1-year follow-up examination showed stable cosmetic and dimensional results in all patients. This study demonstrated that the application of 3D orbital CAS with regards to intra-operative navigation and CAD/CAM techniques allowed for a successful outcome in the patients presented in this series. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. An Analytical Method for Determining the Convection Heat Transfer Coefficient Between Flowing Fluid and Rock Fracture Walls

    NASA Astrophysics Data System (ADS)

    Bai, Bing; He, Yuanyuan; Hu, Shaobin; Li, Xiaochun

    2017-07-01

    The convective heat transfer coefficient (HTC) is a useful indicator that characterizes the convective heat transfer properties between flowing fluid and hot dry rock. An analytical method is developed to explore a more realistic formula for the HTC. First, a heat transfer model is described that can be used to determine the general expression of the HTC. As one of the novel elements, the new model can consider an arbitrary function of temperature distribution on the fracture wall along the direction of the rock radius. The resulting Dirichlet problem of the Laplace equation on a semi-disk is successfully solved with the Green's function method. Four specific formulas for the HTC are derived and compared by assuming the temperature distributions along the radius of the fracture wall to be zeroth-, first-, second-, and third-order polynomials. Comparative verification of the four specific formulas based on the test data shows that the formula A corresponding to the zeroth-order polynomial always predicts stable HTC values. At low flow rates, the four formulas predict similar values of HTC, but at higher flow rates, formulas B and D, respectively, corresponding to the first- and third-order polynomials, predict either too large or too small values of the HTC, while formula C, corresponding to the second-order polynomial, predicts relatively acceptable HTC values. However, we cannot tell which one is the more rational formula between formulas A and C due to the limited information measured. One of the clear advantages of formula C is that it can avoid the drawbacks of the discontinuity of temperature and the singular integral of HTC at the points (± R, 0). Further experimental work to measure the actual temperature distribution of water in the fracture will be of great value. It is also found that the absorbed heat of the fluid, Q, has a significant impact on the prediction results of the HTC. The temperatures at the inlet and the outlet used for Q should be

  3. BUMPERII - DESIGN ANALYSIS CODE FOR OPTIMIZING SPACECRAFT SHIELDING AND WALL CONFIGURATION FOR ORBITAL DEBRIS AND METEOROID IMPACTS

    NASA Technical Reports Server (NTRS)

    Hill, S. A.

    1994-01-01

    BUMPERII is a modular program package employing a numerical solution technique to calculate a spacecraft's probability of no penetration (PNP) from man-made orbital debris or meteoroid impacts. The solution equation used to calculate the PNP is based on the Poisson distribution model for similar analysis of smaller craft, but reflects the more rigorous mathematical modeling of spacecraft geometry, orientation, and impact characteristics necessary for treatment of larger structures such as space station components. The technique considers the spacecraft surface in terms of a series of flat plate elements. It divides the threat environment into a number of finite cases, then evaluates each element of each threat. The code allows for impact shielding (shadowing) of one element by another in various configurations over the spacecraft exterior, and also allows for the effects of changing spacecraft flight orientation and attitude. Four main modules comprise the overall BUMPERII package: GEOMETRY, RESPONSE, SHIELD, and CONTOUR. The GEOMETRY module accepts user-generated finite element model (FEM) representations of the spacecraft geometry and creates geometry databases for both meteoroid and debris analysis. The GEOMETRY module expects input to be in either SUPERTAB Universal File Format or PATRAN Neutral File Format. The RESPONSE module creates wall penetration response databases, one for meteoroid analysis and one for debris analysis, for up to 100 unique wall configurations. This module also creates a file containing critical diameter as a function of impact velocity and impact angle for each wall configuration. The SHIELD module calculates the PNP for the modeled structure given exposure time, operating altitude, element ID ranges, and the data from the RESPONSE and GEOMETRY databases. The results appear in a summary file. SHIELD will also determine the effective area of the components and the overall model, and it can produce a data file containing the probability

  4. BUMPERII - DESIGN ANALYSIS CODE FOR OPTIMIZING SPACECRAFT SHIELDING AND WALL CONFIGURATION FOR ORBITAL DEBRIS AND METEOROID IMPACTS

    NASA Technical Reports Server (NTRS)

    Hill, S. A.

    1994-01-01

    BUMPERII is a modular program package employing a numerical solution technique to calculate a spacecraft's probability of no penetration (PNP) from man-made orbital debris or meteoroid impacts. The solution equation used to calculate the PNP is based on the Poisson distribution model for similar analysis of smaller craft, but reflects the more rigorous mathematical modeling of spacecraft geometry, orientation, and impact characteristics necessary for treatment of larger structures such as space station components. The technique considers the spacecraft surface in terms of a series of flat plate elements. It divides the threat environment into a number of finite cases, then evaluates each element of each threat. The code allows for impact shielding (shadowing) of one element by another in various configurations over the spacecraft exterior, and also allows for the effects of changing spacecraft flight orientation and attitude. Four main modules comprise the overall BUMPERII package: GEOMETRY, RESPONSE, SHIELD, and CONTOUR. The GEOMETRY module accepts user-generated finite element model (FEM) representations of the spacecraft geometry and creates geometry databases for both meteoroid and debris analysis. The GEOMETRY module expects input to be in either SUPERTAB Universal File Format or PATRAN Neutral File Format. The RESPONSE module creates wall penetration response databases, one for meteoroid analysis and one for debris analysis, for up to 100 unique wall configurations. This module also creates a file containing critical diameter as a function of impact velocity and impact angle for each wall configuration. The SHIELD module calculates the PNP for the modeled structure given exposure time, operating altitude, element ID ranges, and the data from the RESPONSE and GEOMETRY databases. The results appear in a summary file. SHIELD will also determine the effective area of the components and the overall model, and it can produce a data file containing the probability

  5. Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon.

    PubMed

    Khanal, S P; Mahfuz, H; Rondinone, A J; Leventouri, Th

    2016-03-01

    The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was studied. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6±0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This value is in the range of the cortical bone fracture toughness. Increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon

    SciTech Connect

    Khanal, Suraj P.; Mahfuz, Hassan; Rondinone, Adam Justin; Leventouri, Th.

    2015-11-12

    The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was researched. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6 ± 0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This value is in the range of the cortical bone fracture toughness. Lastly, the increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases.

  7. Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon

    DOE PAGES

    Khanal, Suraj P.; Mahfuz, Hassan; Rondinone, Adam Justin; ...

    2015-11-12

    The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was researched. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6 ± 0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This valuemore » is in the range of the cortical bone fracture toughness. Lastly, the increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases.« less

  8. [Clinical application of transconjunctival approach to treat orbitozygomatic complex fractures].

    PubMed

    Xiao, Wenzhi; Chen, Yong; Luo, Qi; Liu, Hua; Zhang, Li

    2013-04-01

    To evaluate the effective of transconjunctival approach in treating orbitozygomatic complex fractures. Fifty-four transconjunctival incisions were applied to correct enophthalmos and face collapse in 46 patients who suffered by orbitozygomatic complex fractures. All operative procedures were performed with an additional lateral canthotomy (5-10 mm) and 43 of them with gingivobuccal sulcus incisions simultaneously. The infraorbital rim and lateral orbital wall were stabilized with titanium plates. Titanium nets were used to reconstruct the comminuted orbit floor fractures. The bilateral zygomaticas of 46 cases with orbitozygomatic complex fractures were basically symmetric, and the eyeball positions were reset anatomically. The treatment effectiveness were satisfactory. There were no obvious postoperative complications, except one corneal epithelium stripped on the right side and one overtime swelling of conjunctiva which cured after relevant treatments. The transconjunctival approach has good exposure to the orbital floor without visible scar and injury to facial nerve branches, it is a preferable procedure to reconstruct orbitozygomatic fractures.

  9. Analytical Modeling of Pressure Wall Hole Size and Maximum Tip-to-Tip Crack Length for Perforating Normal and Oblique Orbital Debris Impacts

    NASA Technical Reports Server (NTRS)

    Schonberg, William P.; Mohamed, Essam

    1997-01-01

    This report presents the results of a study whose objective was to develop first-principles-based models of hole size and maximum tip-to-tip crack length for a spacecraft module pressure wall that has been perforated in an orbital debris particle impact. The hole size and crack length models are developed by sequentially characterizing the phenomena comprising the orbital debris impact event, including the initial impact, the creation and motion of a debris cloud within the dual-wall system, the impact of the debris cloud on the pressure wall, the deformation of the pressure wall due to debris cloud impact loading prior to crack formation, pressure wall crack initiation, propagation, and arrest, and finally pressure wall deformation following crack initiation and growth. The model development has been accomplished through the application of elementary shock physics and thermodynamic theory, as well as the principles of mass, momentum, and energy conservation. The predictions of the model developed herein are compared against the predictions of empirically-based equations for hole diameters and maximum tip-to-tip crack length for three International Space Station wall configurations. The ISS wall systems considered are the baseline U.S. Lab Cylinder, the enhanced U.S. Lab Cylinder, and the U.S. Lab Endcone. The empirical predictor equations were derived from experimentally obtained hole diameters and crack length data. The original model predictions did not compare favorably with the experimental data, especially for cases in which pressure wall petalling did not occur. Several modifications were made to the original model to bring its predictions closer in line with the experimental results. Following the adjustment of several empirical constants, the predictions of the modified analytical model were in much closer agreement with the experimental results.

  10. A Study On Critical Thinning In Thin-walled Tube Bending Of Al-Alloy 5052O Via Coupled Ductile Fracture Criteria

    SciTech Connect

    Li Heng; Yang He; Zhan Mei

    2010-06-15

    Thin-walled tube bending(TWTB) method of Al-alloy tube has attracted wide applications in aerospace, aviation and automobile,etc. While, under in-plane double tensile stress states at the extrados of bending tube, the over-thinning induced ductile fracture is one dominant defect in Al-alloy tube bending. The main objective of this study is to predict the critical wall-thinning of Al-alloy tube bending by coupling two ductile fracture criteria(DFCs) into FE simulation. The DFCs include Continuum Damage Mechanics(CDM)-based model and GTN porous model. Through the uniaxial tensile test of the curved specimen, the basic material properties of the Al-alloy 5052O tube is obtained; via the inverse problem solution, the damage parameters of both the two fracture criteria are interatively determined. Thus the application study of the above DFCs in the TWTB is performed, and the more reasonable one is selected to obtain the critical thinning of Al-alloy tube in bending. The virtual damage initiation and evolution (when and where the ductile fracture occurs) in TWTB are investigated, and the fracture mechanisms of the voided Al-alloy tube in tube bending are consequently discussed.

  11. Non-perturbative modelling of energetic particle effects on resistive wall mode: Anisotropy and finite orbit widtha)

    NASA Astrophysics Data System (ADS)

    Liu, Yueqiang; Chapman, I. T.; Graves, J. P.; Hao, G. Z.; Wang, Z. R.; Menard, J. E.; Okabayashi, M.; Strait, E. J.; Turnbull, A.

    2014-05-01

    A non-perturbative magnetohydrodynamic-kinetic hybrid formulation is developed and implemented into the MARS-K code [Liu et al., Phys. Plasmas 15, 112503 (2008)] that takes into account the anisotropy and asymmetry [Graves et al., Nature Commun. 3, 624 (2012)] of the equilibrium distribution of energetic particles (EPs) in particle pitch angle space, as well as first order finite orbit width (FOW) corrections for both passing and trapped EPs. Anisotropic models, which affect both the adiabatic and non-adiabatic drift kinetic energy contributions, are implemented for both neutral beam injection and ion cyclotron resonant heating induced EPs. The first order FOW correction does not contribute to the precessional drift resonance of trapped particles, but generally remains finite for the bounce and transit resonance contributions, as well as for the adiabatic contributions from asymmetrically distributed passing particles. Numerical results for a 9MA steady state ITER plasma suggest that (i) both the anisotropy and FOW effects can be important for the resistive wall mode stability in ITER plasmas; and (ii) the non-perturbative approach predicts less kinetic stabilization of the mode, than the perturbative approach, in the presence of anisotropy and FOW effects for the EPs. The latter may partially be related to the modification of the eigenfunction of the mode by the drift kinetic effects.

  12. Non-perturbative modelling of energetic particle effects on resistive wall mode: Anisotropy and finite orbit width

    SciTech Connect

    Liu, Yueqiang Chapman, I. T.; Hao, G. Z.; Wang, Z. R.; Menard, J. E.; Okabayashi, M.; Strait, E. J.; Turnbull, A.

    2014-05-15

    A non-perturbative magnetohydrodynamic-kinetic hybrid formulation is developed and implemented into the MARS-K code [Liu et al., Phys. Plasmas 15, 112503 (2008)] that takes into account the anisotropy and asymmetry [Graves et al., Nature Commun. 3, 624 (2012)] of the equilibrium distribution of energetic particles (EPs) in particle pitch angle space, as well as first order finite orbit width (FOW) corrections for both passing and trapped EPs. Anisotropic models, which affect both the adiabatic and non-adiabatic drift kinetic energy contributions, are implemented for both neutral beam injection and ion cyclotron resonant heating induced EPs. The first order FOW correction does not contribute to the precessional drift resonance of trapped particles, but generally remains finite for the bounce and transit resonance contributions, as well as for the adiabatic contributions from asymmetrically distributed passing particles. Numerical results for a 9MA steady state ITER plasma suggest that (i) both the anisotropy and FOW effects can be important for the resistive wall mode stability in ITER plasmas; and (ii) the non-perturbative approach predicts less kinetic stabilization of the mode, than the perturbative approach, in the presence of anisotropy and FOW effects for the EPs. The latter may partially be related to the modification of the eigenfunction of the mode by the drift kinetic effects.

  13. Diagnostic performance of isolated orbital CT scan for assessment of globe rupture in acute blunt facial trauma.

    PubMed

    Chou, Chieh; Lou, Yun-Ting; Hanna, Eissa; Huang, Shu-Hung; Lee, Su-Shin; Lai, Hsin-Ti; Chang, Kao-Ping; Wang, Hui-Min David; Chen, Chao-Wen

    2016-05-01

    We determine the diagnostic performance of emergent orbital computed tomography (CT) scans for assessing globe rupture in patients with blunt facial trauma. We performed a retrospective cohort study based on prospectively collected trauma registry and acute care surveillance data in a tertiary-care hospital. Patients aged at least 18 years who underwent isolated orbital CT scanning for assessing potential ocular trauma were examined. Analyses were performed to evaluate the magnitude of agreement between diagnosis by CT scanning and ophthalmic assessment, including globe rupture. Our study cohort comprised 136 patients, 30% of whom (41 patients) sustained orbital wall fractures. Concordance for orbital CT diagnosis and the ophthalmic assessment of globe rupture was substantial (k=0.708). The relative risk of globe rupture was 0.692 (95% confidence interval (CI): 0.054-8.849) for superior wall fractures, 0.459 (95% CI: 0.152-1.389) for inferior wall fractures, 2.286 (95% CI: 1.062-4.919) for lateral wall fractures, and 0.637 (95% CI: 0.215-1.886) for medial wall fractures. According to multivariate analysis, lateral wall fractures were an independent risk factor for globe ruptures (adjusted odds ratio (OR)=12.01, P=0.011), and medial or inferior wall fracture was a protective factor (adjusted OR=0.14, P=0.012). In the stratified analysis of diagnostic performance of CT scan, specificity was highest among patients with orbital wall fractures (97.2%), followed by negative predictive volume (NPV, 97%), and accuracy (95.1%). Among patients with blunt facial trauma who underwent isolated orbital CT scanning as part of ocular trauma assessment, the diagnostic performance of CT in detecting globe rupture is more accurate in patients with orbital wall fractures. Nevertheless, isolated orbital CT alone does not have a sufficiently high diagnostic performance to be reliable to rule out all globe ruptures. Lateral orbital wall fractures in blunt facial trauma patients, in

  14. Slow dust in Enceladus' plume from condensation and wall collisions in tiger stripe fractures.

    PubMed

    Schmidt, Jürgen; Brilliantov, Nikolai; Spahn, Frank; Kempf, Sascha

    2008-02-07

    One of the spectacular discoveries of the Cassini spacecraft was the plume of water vapour and icy particles (dust) originating near the south pole of Saturn's moon Enceladus. The data imply considerably smaller velocities for the grains than for the vapour, which has been difficult to understand. The gas and dust are too dilute in the plume to interact, so the difference must arise below the surface. Here we report a model for grain condensation and growth in channels of variable width. We show that repeated wall collisions of grains, with re-acceleration by the gas, induce an effective friction, offering a natural explanation for the reduced grain velocity. We derive particle speed and size distributions that reproduce the observed and inferred properties of the dust plume. The gas seems to form near the triple point of water; gas densities corresponding to sublimation from ice at temperatures less than 260 K are generally too low to support the measured particle fluxes. This in turn suggests liquid water below Enceladus' south pole.

  15. Prevalence of Diplopia and Extraocular Movement Limitation according to the Location of Isolated Pure Blowout Fractures

    PubMed Central

    Park, Min Seok; Kim, Young Joon; Kim, Hoon; Nam, Sang Hyun

    2012-01-01

    Background Isolated pure blowout fractures are clinically important because they are the main cause of serious complications such as diplopia and limitation of extraocular movement. Many reports have described the incidence of blowout fractures associated with diplopia and limitation of extraocular movement; however, no studies have statistically analyzed this relationship. The purpose of this study was to demonstrate the correlation between the location of isolated pure blowout fractures and orbital symptoms such as diplopia and limitation of extraocular movement. Methods We enrolled a total of 354 patients who had been diagnosed with isolated pure blowout fractures, based on computed tomography, from June 2008 to November 2011. Medical records were reviewed, and the prevalence of extraocular movement limitations and diplopia were determined. Results There were 14 patients with extraocular movement limitation and 58 patients complained of diplopia. Extraocular movement limitation was associated with the following findings, in decreasing order of frequency: floor fracture (7.1%), extended fracture (3.6%), and medial wall (1.7%). However, there was no significant difference among the types of fractures (P=0.60). Diplopia was more commonly associated with floor fractures (21.4%) and extended type fractures (23.6%) than medial wall fractures (10.4%). The difference was statistically significant (Bonferroni-corrected chi-squared test P<0.016). Conclusions Data indicate that extended type fractures and orbital floor fractures tend to cause diplopia more commonly than medial wall fractures. However, extraocular movement limitation was not found to be dependent on the location of the orbital wall fracture. PMID:22783527

  16. Isogeometric Analysis of Deformation, Inelasticity and Fracture In Thin-Walled Structures

    NASA Astrophysics Data System (ADS)

    de Borst, René

    2016-08-01

    The basic idea of isogeometric analysis (IGA) is to use splines, which are the functions commonly used in computer-aided design (CAD) to describe the geometry, as the basis function for the analysis as well. A main advantage is that a sometimes elaborate meshing process is by-passed. Another benefit is that spline basis-functions possess a higher-order degree of continuity, which enables a more accurate representation of the stress. Further, the order of continuity of the basis-functions can be reduced locally by knot insertion. This feature can be used to model interfaces and cracks as discontinuities in the displacement field. In order to study failure-mechanisms in thin-walled composite materials, an accurate representation of the full three-dimensional stress field is mandatory. A continuum shell formulation is an obvious choice. Continuum shell elements can be developed based on the isogeometric concept. They exploit NURBS basis functions to construct the mid-surface of the shell. In combination with a higher-order B-spline basis function in the thickness direction a complete three-dimensional representation of the shell is obtained. This isogeometric shell formulation can be implemented in a standard finite element code using Bézier extraction. Weak and strong discontinuities can be introduced in the B-spline function using knot-insertion to model material interfaces and delaminations rigorously as discontinuities in the displacement field. The exact representation of material interfaces vastly improves the accuracy of the through-the- thickness stress field. The ability to provide a double knot insertion enables a straightforward analysis of delamination growth in layered composite shells. Illustrative examples will be given.

  17. Evaluation of the Biodegradable Plates (PG910/PDO) for Reconstruction of Various Sizes of Orbital Floor Defects in the Blow-Out Fractures.

    PubMed

    Tabrizi, Reza; Langner, Nicole J; Pouzesh, Ayatollah; Arabion, Hamidreza

    2013-09-01

    The aim of our study was to evaluate the biodegradable plates (PG910/PDO) for reconstruction of various sizes of the orbital floor defects in the blow-out fractures. We included patients who had an impure blow-out fracture. All patients had a recent trauma and also the surgical intervention was done between 1 and 10 days after trauma. The amount of the orbital floor defect was measured in each case through computed tomography scan. In the surgical intervention, a biodegradable plate was used for the reconstruction of the orbital floor defect along with titanium miniplates used for bone fixation in orbital rim. Due to aesthetic reasons, all patients underwent secondary surgery including removal of titanium miniplates after 18 months. The orbital floor was reevaluated during the removal of the miniplates. The clinical evaluation of remnant defects and biodegradable plates (presence of complete or partial resorption) were documented for each patient. In our study a total of 15 patients (10 males and 5 females) underwent the orbital floor reconstruction using biodegradable miniplates. The size of the orbital floor defects was meanly 3.51 ± 1.29 cm(2). Results demonstrated that 4 out of 15 patients had a remnant defect after resorption of the biodegradable plate. In 10 out of 15 patients, the biodegradable plates completely replaced with fibrous tissues after 18 months. Remaining five patients had partial resorption of plates. There was not any relationship between the defect size and the remnant defects (p > 0.05). A significant relationship was seen between the defect size and the plates' resorption rate (p < 0.001). There is a significant relationship between the resorption rate and the remnant defect. The risk to have remnant defects have been increased as the plates had incomplete resorption. The use of biodegradable plates is an appropriate option for reconstruction of the orbital floor defects. The defect size does not have any effect on the stability of the

  18. Orbital emphysema following nose blowing as a sequel of a snowboard related head injury.

    PubMed

    Taguchi, Y; Sakakibara, Y; Uchida, K; Kishi, H

    2004-10-01

    A case of orbital emphysema as a sequel of a snowboard related head injury is reported. It is believed that a fracture of the medial orbital wall was caused by the increased intraorbital pressure when the patient hit his forehead on the snowy ground, allowing air to enter the orbit when he blew his nose. Wearing goggles may prevent this type of sports related injury.

  19. Chest wall pain and rib fracture after stereotactic radiotherapy for peripheral non-small cell lung cancer.

    PubMed

    Voroney, Jon-Paul J; Hope, Andrew; Dahele, Max R; Purdie, Thomas G; Purdy, Thomas; Franks, Kevin N; Pearson, Shannon; Cho, John B C; Sun, Alex; Payne, David G; Bissonnette, Jean-Pierre; Bezjak, Andrea; Brade, Anthony M

    2009-08-01

    Stereotactic body radiotherapy is an emerging treatment option for peripheral non-small cell lung cancer in medically inoperable patients. With high dose per fraction radiotherapy, late side effects are of possible concern. In our initial cohort of 42 patients treated with 54 to 60 Gy in three fractions, nine patients have rib fracture. The median dose to rib fracture sites was 46 to 50 Gy, depending on the method of dose calculation. We describe a typical case of poststereotactic radiotherapy rib fracture and present dosimetric analysis of patients with rib fracture.

  20. Chest wall volume receiving >30 Gy predicts risk of severe pain and/or rib fracture after lung stereotactic body radiotherapy.

    PubMed

    Dunlap, Neal E; Cai, Jing; Biedermann, Gregory B; Yang, Wensha; Benedict, Stanley H; Sheng, Ke; Schefter, Tracey E; Kavanagh, Brian D; Larner, James M

    2010-03-01

    To identify the dose-volume parameters that predict the risk of chest wall (CW) pain and/or rib fracture after lung stereotactic body radiotherapy. From a combined, larger multi-institution experience, 60 consecutive patients treated with three to five fractions of stereotactic body radiotherapy for primary or metastatic peripheral lung lesions were reviewed. CW pain was assessed using the Common Toxicity Criteria for pain. Peripheral lung lesions were defined as those located within 2.5 cm of the CW. A minimal point dose of 20 Gy to the CW was required. The CW volume receiving >or=20, >or=30, >or=40, >or=50, and >or=60 Gy was determined and related to the risk of CW toxicity. Of the 60 patients, 17 experienced Grade 3 CW pain and five rib fractures. The median interval to the onset of severe pain and/or fracture was 7.1 months. The risk of CW toxicity was fitted to the median effective concentration dose-response model. The CW volume receiving 30 Gy best predicted the risk of severe CW pain and/or rib fracture (R(2) = 0.9552). A volume threshold of 30 cm(3) was observed before severe pain and/or rib fracture was reported. A 30% risk of developing severe CW toxicity correlated with a CW volume of 35 cm(3) receiving 30 Gy. The development of CW toxicity is clinically relevant, and the CW should be considered an organ at risk in treatment planning. The CW volume receiving 30 Gy in three to five fractions should be limited to <30 cm(3), if possible, to reduce the risk of toxicity without compromising tumor coverage. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  1. Chest Wall Volume Receiving >30 Gy Predicts Risk of Severe Pain and/or Rib Fracture After Lung Stereotactic Body Radiotherapy

    SciTech Connect

    Dunlap, Neal E.; Cai, Jing; Biedermann, Gregory B.; Yang, Wensha; Benedict, Stanley H.; Sheng Ke; Schefter, Tracey E.; Kavanagh, Brian D.; Larner, James M.

    2010-03-01

    Purpose: To identify the dose-volume parameters that predict the risk of chest wall (CW) pain and/or rib fracture after lung stereotactic body radiotherapy. Methods and Materials: From a combined, larger multi-institution experience, 60 consecutive patients treated with three to five fractions of stereotactic body radiotherapy for primary or metastatic peripheral lung lesions were reviewed. CW pain was assessed using the Common Toxicity Criteria for pain. Peripheral lung lesions were defined as those located within 2.5 cm of the CW. A minimal point dose of 20 Gy to the CW was required. The CW volume receiving >=20, >=30, >=40, >=50, and >=60 Gy was determined and related to the risk of CW toxicity. Results: Of the 60 patients, 17 experienced Grade 3 CW pain and five rib fractures. The median interval to the onset of severe pain and/or fracture was 7.1 months. The risk of CW toxicity was fitted to the median effective concentration dose-response model. The CW volume receiving 30 Gy best predicted the risk of severe CW pain and/or rib fracture (R{sup 2} = 0.9552). A volume threshold of 30 cm{sup 3} was observed before severe pain and/or rib fracture was reported. A 30% risk of developing severe CW toxicity correlated with a CW volume of 35 cm{sup 3} receiving 30 Gy. Conclusion: The development of CW toxicity is clinically relevant, and the CW should be considered an organ at risk in treatment planning. The CW volume receiving 30 Gy in three to five fractions should be limited to <30 cm{sup 3}, if possible, to reduce the risk of toxicity without compromising tumor coverage.

  2. Transconjunctival orbital emphysema caused by compressed air injury: A case report

    PubMed Central

    Vasu, Usha; Francis, Febson; Nazareth, Colin

    2008-01-01

    Orbital emphysema following conjunctival tear in the absence of orbital wall fracture, caused by air under pressure is rare. Usually orbital emphysema is seen in facial trauma associated with damage to the adjacent paranasal sinuses or facial bones. To the best of our knowledge, there have been only eight reports of orbital emphysema following use of compressed air during industrial work. The air under pressure is pushed through the subconjunctival space into the subcutaneous and retrobulbar spaces. We present here a rare cause of orbital emphysema in a young man working with compressed air gun. Although the emphysema was severe, there were no orbital bone fracture and the visual recovery of the patient was complete without attendant complications. PMID:18417833

  3. Straightforward factors for predicting the prognosis of blow-out fractures.

    PubMed

    Higashino, Takuya; Hirabayashi, Shinichi; Eguchi, Tomoaki; Kato, Yuki

    2011-07-01

    In blow-out fractures, some nonoperative cases have a poor outcome, and a method for accurate prognosis is required. To address this need, we retrospectively reviewed blow-out fractures presenting at Teikyo University Hospital between July 2004 and May 2007 and conducted a survey regarding diplopia and enophthalmos for nonoperative cases. Computed tomographic scan findings were divided according to fracture width and the degree of protrusion of the inferior rectus muscle into the maxillary sinus. We had 106 patients presenting with blow-out fractures, and 89 patients had been treated nonoperatively. In medial orbital wall fractures, no patient had diplopia, and 1 patient had enophthalmos after nonoperative treatment. In punched-out orbital floor fractures, all cases had diplopia when the fracture width was less than half the diameter of the globe, and the protrusion of the inferior rectus muscle into the maxillary sinus was half or more of its section. Even if the fracture width was less than half the diameter of the globe, 2 of 3 patients had enophthalmos when the protrusion of the inferior rectus muscle into the maxillary sinus was half or more of its section. Among the linear orbital floor fractures, 1 case required an emergency operation. We suggest a new algorithm for treatment of blow-out fractures based on computed tomographic scan findings that can also contribute to making a prognosis.

  4. [Morphological changes in gastric wall of mongolian gerbils following the 12-day orbital flight aboard Foton-M3].

    PubMed

    Atiashkin, D A; Bykov, É G

    2012-01-01

    Gastric wall of Meriones unguiculatus is distinguished by species-specific properties arising from the peculiar proportion of interstitium, muscle and epithelial tissues. Exposure to the factors of the 12-d Foton-M3 flight led to microfocal lesions of the mucous coat, dystrophic developments in the acid glands, dissociation of the mucous barrier function and deterioration of its biosynthetic function. Modifications of the tinctorial properties of the interstitium reticulum in every stomach layer progressed concurrently with reductions in prismatic epithelium height, as well as in mucous and muscular layer thickness. It is assumed that existence in the low gravity aboard the Biosat stimulated involutory processes in the gastric wall. Animals of the ground synchronous control conducted in the flight equipment mockup (Kontur-L) exhibited though similar yet less pronounced changes.

  5. Limited-interval definitions of the photometric functions of lunar crater walls by photography from orbiting Apollo

    USGS Publications Warehouse

    Wildey, R.L.

    1971-01-01

    By the use of only relative photometry (intraframe) it is shown that the photometric functions of material reposed on the inner walls of some of the ypunger lunar craters photographed on the far side of the Moon from the Apollo 11 Command Module are not of a form which can be reduced to a dependence on phase angle and brightness-longitude (g, ??) alone. Some other dependence on the completely general degrees of freedom described by phase angle, angle of incidence, and angle of emergence (g, i, ??{lunate}) seems to be required. In addition, however, it has been found that a dependence of g and ?? is more closely approached for the crater, in the group observed, which is obviously the oldest by virtue of the roundedness of the rim crest and the mass-wasting which has occured on its inner walls. The possibility thus arises of crater age-dating by making a brightness ratio measurement together with some image geometry measurements. It is at least evident that more than one type of geologic material has been encountered. ?? 1971.

  6. Fast switching and signature of efficient domain wall motion driven by spin-orbit torques in a perpendicular anisotropy magnetic insulator/Pt bilayer

    NASA Astrophysics Data System (ADS)

    Avci, Can Onur; Rosenberg, Ethan; Baumgartner, Manuel; Beran, Lukáš; Quindeau, Andy; Gambardella, Pietro; Ross, Caroline A.; Beach, Geoffrey S. D.

    2017-08-01

    We report fast and efficient current-induced switching of a perpendicular anisotropy magnetic insulator thulium iron garnet by using spin-orbit torques (SOT) from the Pt overlayer. We first show that, with quasi-DC (10 ms) current pulses, SOT-induced switching can be achieved with an external field as low as 2 Oe, making TmIG an outstanding candidate to realize efficient switching in heterostructures that produce moderate stray fields without requiring an external field. We then demonstrate deterministic switching with fast current pulses (≤20 ns) with an amplitude of ˜1012 A/m2, similar to all-metallic structures. We reveal that, in the presence of an initially nucleated domain, the critical switching current is reduced by up to a factor of five with respect to the fully saturated initial state, implying efficient current-driven domain wall motion in this system. Based on measurements with 2 ns-long pulses, we estimate the domain wall velocity of the order of ˜400 m/s per j = 1012 A/m2.

  7. High efficiency of the spin-orbit torques induced domain wall motion in asymmetric interfacial multilayered Tb/Co wires

    SciTech Connect

    Bang, Do; Awano, Hiroyuki

    2015-05-07

    We investigated current-induced DW motion in asymmetric interfacial multilayered Tb/Co wires for various thicknesses of magnetic and Pt-capping layers. It is found that the driving mechanism for the DW motion changes from interfacial to bulk effects at much thick magnetic layer (up to 19.8 nm). In thin wires, linearly depinning field dependence of critical current density and in-plane field dependence of DW velocity suggest that the extrinsic pinning governs field-induced DW motion and injecting current can be regarded as an effective field. It is expected that the high efficiency of spin-orbit torques in thick magnetic multilayers would have important implication for future spintronic devices based on in-plane current induced-DW motion or switching.

  8. High efficiency of the spin-orbit torques induced domain wall motion in asymmetric interfacial multilayered Tb/Co wires

    NASA Astrophysics Data System (ADS)

    Bang, Do; Awano, Hiroyuki

    2015-05-01

    We investigated current-induced DW motion in asymmetric interfacial multilayered Tb/Co wires for various thicknesses of magnetic and Pt-capping layers. It is found that the driving mechanism for the DW motion changes from interfacial to bulk effects at much thick magnetic layer (up to 19.8 nm). In thin wires, linearly depinning field dependence of critical current density and in-plane field dependence of DW velocity suggest that the extrinsic pinning governs field-induced DW motion and injecting current can be regarded as an effective field. It is expected that the high efficiency of spin-orbit torques in thick magnetic multilayers would have important implication for future spintronic devices based on in-plane current induced-DW motion or switching.

  9. Fractured Craters on Ganymede

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Two highly fractured craters are visible in this high resolution image of Jupiter's moon, Ganymede. NASA's Galileo spacecraft imaged this region as it passed Ganymede during its second orbit through the Jovian system. North is to the top of the picture and the sun illuminates the surface from the southeast. The two craters in the center of the image lie in the ancient dark terrain of Marius Regio, at 40 degrees latitude and 201 degrees longitude, at the border of a region of bright grooved terrain known as Byblus Sulcus (the eastern portion of which is visible on the left of this image). Pervasive fracturing has occurred in this area that has completely disrupted these craters and destroyed their southern and western walls. Such intense fracturing has occurred over much of Ganymede's surface and has commonly destroyed older features. The image covers an area approximately 26 kilometers (16 miles) by 18 kilometers (11 miles) across at a resolution of 86 meters (287 feet) per picture element. The image was taken on September 6, 1996 by the solid state imaging (CCD) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  10. Fractured Craters on Ganymede

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Two highly fractured craters are visible in this high resolution image of Jupiter's moon, Ganymede. NASA's Galileo spacecraft imaged this region as it passed Ganymede during its second orbit through the Jovian system. North is to the top of the picture and the sun illuminates the surface from the southeast. The two craters in the center of the image lie in the ancient dark terrain of Marius Regio, at 40 degrees latitude and 201 degrees longitude, at the border of a region of bright grooved terrain known as Byblus Sulcus (the eastern portion of which is visible on the left of this image). Pervasive fracturing has occurred in this area that has completely disrupted these craters and destroyed their southern and western walls. Such intense fracturing has occurred over much of Ganymede's surface and has commonly destroyed older features. The image covers an area approximately 26 kilometers (16 miles) by 18 kilometers (11 miles) across at a resolution of 86 meters (287 feet) per picture element. The image was taken on September 6, 1996 by the solid state imaging (CCD) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  11. Comparison of the amounts of canal encroachment between semisitting and supine position of computed tomography-myelography for vertebral fractures of the elderly involving the posterior vertebral wall.

    PubMed

    Hayashi, Tetsuo; Maeda, Takeshi; Ueta, Takayoshi; Shiba, Keiichiro; Iwamoto, Yukihide

    2012-09-01

    A prospective radiographical trial. To elucidate effects of loading associated with spinal canal encroachment (SCE) in patients with insufficient bone union after vertebral fractures in the elderly, using computed tomography-myelography in 2 different positions. In elderly patients with vertebral fractures, influence of loading would be involved in SCE, but the details are not well understood. Seventeen patients (mean age, 77.4 ± 8 yr; range, 62-91 yr) with various degrees of neurological deficit due to insufficient bone union at both vertebral body and posterior vertebral wall were included in this study. Computed tomography-myelography was performed in both semisitting and supine positions. Kyphotic angle, rate of dural compression, ratio of occupation by bony fragments, and posterior vertebral body height ratio were measured and compared between positions. Mean ratio of occupation by bony fragments was significantly higher in the semisitting position (47.9 ± 9.2%) than in the supine position (33.9 ± 10.0%, P, 0.001). Similarly, mean posterior vertebral body height ratio was significantly lower in the semisitting position (67.8 ± 10.8%) than in the supine position (76.3 ± 13.3%), indicating a significant loss of vertebral height in the semisitting position (P, 0.001). Mean rate of dural compression was likewise significantly higher in the semisitting position (48.6 ± 13.3%) than in the supine position (33.3 ± 16.5%; P, 0.001). Mean change in ratio of occupation by bony fragments, change in posterior vertebral body height ratio, and angular instability between positions were 13.9 ± 8.6%, 8.5 ± 6.7%, and 13° ± 5.7°, respectively. A significant correlation was identified between change in ratio of occupation by bony fragments and change in posterior vertebral body height ratio (P = 0.001). Our study demonstrated that collapse of the nonunited posterior vertebral wall and intracanal protrusion of vertebral fragments would occur simultaneously with axial

  12. Effectiveness of Computed Tomography for Blow-out Fracture

    PubMed Central

    Rhee, Seung-Hyun; Kim, Tae-Seup; Song, Jae-Min; Shin, Sang-Hoon; Lee, Jae-Yeol

    2014-01-01

    Purpose: This study assessed the association between eye symptoms (enophthalmos or diplopia) and site of damage, volume, deviated inferior rectus muscle (IRM) and type of fracture with computed tomography (CT). The intent is to anticipate the prognosis of orbital trauma at initial diagnosis. Methods: Forty-five patients were diagnosed with fractures of the inferior wall of one orbit. Fracture area, volume of displaced tissue, deviated IRM, and type of fracture were evaluated from coronal CT by one investigator. The association of those variables with the occurrence of eye symptoms (diplopia and enophthalmos) was assessed. Results: Of 45 patients, 27 were symptom-free (Group A) and 18 had symptoms (Group B) of enophthalmos and/or diplopia. In Group B, 12 had diplopia, one was enophthalmos, and five had both. By CT measurement, group A mean area was 192.6 mm2 and the mean volume was 673.2 mm3. Group B area was 316.2 mm2 and volume was 1,710.6 mm3. The volume was more influential on symptom occurrence. Each patient was categorized into four grades depending on the location of IRM. Symptom occurrence and higher grade were associated. Twenty-six patients had trap-door fracture (one side, attached to the fracture), and 19 had punched-out fracture (both sides detached). The punched-out fracture was more strongly associated with symptoms and had statistically significantly higher area and volume. Conclusion: In orbital trauma, measurement of fracture area and volume, evaluation of the deviated IRM and classification of the fracture type by coronal CT can effectively predict prognosis and surgical indication. PMID:27489846

  13. Fractured Mounds in Elysium Planitia

    NASA Image and Video Library

    2010-10-15

    This observation from NASA Mars Reconnaissance Orbiter shows fractured mounds on the southern edge of Elysium Planitia. The fractures that crisscross their surfaces are probably composed of solidified lava.

  14. Medpor implant fixation using fibrin glue in blowout fracture surgery.

    PubMed

    Kyung, Hyunwoo; Song, Seung Han; Kang, Nakheon; Oh, Sang-Ha

    2013-01-01

    The Medpor implant is (Prous polyethylene, Porex Surgical Inc, Newnan, GA, USA) widely used to reconstruct orbital wall defects. However, this implant is commonly associated with numerous complications, including implant displacement. Therefore, the authors have hypothesized that fixation of the Medpor implant with fibrin glue (Tisseel, Baxter Healthcare, Norfolk, UK), compared to other fixation methods, may be more stable and could provide better results than other fixation methods.In this study, 485 patients who had been treated for blowout fractures from 2008 to 2012 were evaluated. Medpor implants fixed using Tisseel were used to reconstruct bone defects of the orbital wall. The patients' hospital records and radiologic images were reviewed according to sex, fracture site, and postoperative complications.According to retrospective chart review and radiologic evaluation, the complication rate was low and included diplopia (7%; 33 patients), enophthalmos (4%; 17 patients), and extraocular movement limitation (3%; 13 patients).This study suggests that Medpor implant fixation using Tisseel is a simpler, more secure, and more suitable for reconstruction of the fractured orbital wall compared with other methods.

  15. Precision of posttraumatic primary orbital reconstruction using individually bent titanium mesh with and without navigation: a retrospective study

    PubMed Central

    2013-01-01

    Background The aim of orbital wall reconstruction is to reestablish anatomically exact orbital volumes to avoid long-term complications. Navigation could facilitate complex reconstructions. Methods Quality of the orbital reconstruction (n = 94) was measured based on (A) volume changes and (B) on 3D shape deviations compared to the unaffected side. Volume analysis included segmentation of the orbital cavity in the pre- and post-operative 3D data set (VoXim®, IVS Solutions, Germany), and shape analysis was performed by vector-based 3D tools (Comparison®, 3Dshape, Germany). Results Orbital volume of the unaffected side ranged from 26.6 ml ± 2.8 ml in male and 25.2 ml ± 2.6 ml in female (CT). Significant orbital enlargement was found in orbital fractures with involvement of the posterior third of the orbital floor and in comminuted fracture pattern. Reconstructed orbital volume ranged from 26.9 ± 2.7 ml in male and 24.26 ± 2.5 ml in female (CBCT). 3D Analysis of the color mapping showed minor deviations compared to the mirrored unaffected side. Conclusion Measurements demonstrate that even in comminuted orbital fractures true-to-original reconstruction is feasible. PMID:23815979

  16. Clinical characteristics and treatment of blow-out fracture accompanied by canalicular laceration.

    PubMed

    Lee, Hwa; Ahn, Jaemoon; Lee, Tae Eun; Lee, Jong Mi; Shin, Hyungho; Chi, Mijung; Park, Minsoo; Baek, Sehyun

    2012-09-01

    Blow-out fracture and canalicular laceration can occur simultaneously as a result of the same trauma. Despite its importance, little research has been conducted to identify clinical characteristics or surgical techniques for repair of a blow-out fracture accompanied by canalicular laceration. The aim of this study was to evaluate the clinical characteristics, the surgical approach, and the outcomes. Thirty-four eyes of 34 patients who underwent simultaneous repair of canalicular laceration using silicone tube intubation and reconstruction of blow-out fracture were included. Medical records were retrospectively reviewed for patient demographics, nature of injury, affected canaliculus, location, and severity of blow-out fracture, associated facial bone fracture, ophthalmic diagnosis, length of follow-up period, and surgical outcome. Mean patient age was 40.0 years (range, 17-71 y). The mean follow-up was 7.3 months. Fist to the orbital area (10 patients, 29.4%) was the most common cause. There were 24 lower canalicular lacerations (70.6%), 6 upper canalicular lacerations (17.6%), and 4 upper and lower canalicular lacerations (11.8%). Isolated medial wall fractures were most common (area A4: 20/34, 58.8%). Fractures involving both the floor and medial wall and maxillo-ethmoidal strut (areas A1, A2, A3, and A4) were the second most common (6/34, 17.6%), and floor and medial wall with intact strut (areas A1, A2, and A4) were injured in 6 patients (17.6%). Pure inferior wall fractures were least frequent (areas A1 and A2: 2/34, 5.9%). The severity of the fracture was severe in most patients except for 1 linear fracture with tissue entrapment and 1 moderate medial wall fracture (32/34, 94.1%). There was lid laceration in 20 patients (58.8%). Nasal bone fracture (5/34, 14.7%) was the most common facial bone fracture. Tubes were removed at a mean of 3.3 months (range, 3-4 mo). In total, 31 patients (91.2%) achieved complete success in canalicular laceration and blow

  17. Orbital dystopia due to orbital roof defect.

    PubMed

    Rha, Eun Young; Joo, Hong Sil; Byeon, Jun Hee

    2013-01-01

    We performed a retrospective review of patients who presented with delayed dystopia as a consequence of an orbital roof defect due to fractures and nontraumatic causes to search for a correlation between orbital roof defect size and surgical indications for the treatment thereof. Retrospective analyses were performed in 7 patients, all of whom presented with delayed dystopia due to orbital roof defects, between January 2001 and June 2011. The causes of orbital roof defects were displaced orbital roof fractures (5 cases), tumor (1 case), and congenital sphenoid dysplasia (1 case). All 7 patients had initially been treated conservatively and later presented with significant dystopia. The sizes of the defects were calculated on computed tomographic scans. Among the 7 patients, aspiration of cerebrospinal fluid, which caused ocular symptoms, in 1 patient with minimal displaced orbital roof and reconstruction with calvarial bone, titanium micromesh, or Medpor in 6 other patients were performed. The minimal size of the orbital roof in patients who underwent orbital roof reconstruction was 1.2 cm (defect height) x 1.0 cm (defect length), 0.94 cm(2). For all patients with orbital dystopia, displacement of the globe was corrected without any complications, regardless of whether the patient was evaluated grossly or by radiology. In this retrospective study, continuous monitoring of clinical signs and active surgical management should be considered for cases in which an orbital roof defect is detected, even if no definite symptoms are noted, to prevent delayed sequelae.

  18. Diplopia secondary to orbital surgery.

    PubMed

    Silbert, David I; Matta, Noelle S; Singman, Eric L

    2012-01-01

    Diplopia may occur following any type of ocular or pericocular surgery. The surgeries most frequently associated with postoperative diplopia include: repair of orbital fracture, endoscopic sinus surgery (from inadvertent orbital penetration), and orbital decompression for thyroid-related immune orbitopathy (TRIO). Postoperative diplopia after orbital tumor resection has been reported--e.g., after excision of fibrous dysplasia and osteoma. However, a recent case series suggests diplopia after orbital tumor resection is uncommon and transient. Surgical intervention for orbital trauma carries the highest risk of postoperative diplopia and will be the focus of this review. We will also present a case report of worsening diplopia following repair of orbital floor fracture to highlight potential motility issues that can arise when implants are employed to treat orbital floor fractures.

  19. Boxer's fracture.

    PubMed

    Altizer, Linda

    2006-01-01

    Boxer's fracture is a common name for a fracture of the distal fifth metacarpal and received its name from one of its most common causes, punching an object with a closed fist. It can occur from a fistfight or from punching a hard object. The injury of a "Boxer's Fracture" earned the name from the way in which the injury occurred, punching an immovable object with a closed fist and no boxing mitt (Figure 1). Naturally, a "Boxer" usually punches his fist into his opponent's face or body. An angry person may perform the same action into a person, or into the wall. The third person may be performing a task and strike something with his fist with forceful action accidentally. In any event, if the closed fist "punches" into an immovable or firm object with force, the most frequent injury sustained would be a fracture of the fifth metacarpal neck. Some caregivers would also call a fourth metacarpal neck fracture a boxer's fracture.

  20. True Triaxial Strength and Brittle Fracture of the Granodiorite at the SAFOD Drillhole Wall, and the Potential for Estimating the Maximum Horizontal Principal Stress

    NASA Astrophysics Data System (ADS)

    Lee, H.; Haimson, B.

    2007-12-01

    Salinian granodiorite core from the 1462-1470m segment of the SAFOD drillhole was used to derive its critical mechanical properties under true triaxial stress conditions, analyze shear localization and brittle fracture characteristics, and establish the strength criterion under dry conditions (Eos Trans. AGU, 87/52, Abstract T32C- 03). Here we report on a series of true triaxial tests on 'unjacketed' specimens simulating stress conditions prevailing at the drillhole wall and responsible for borehole failure in the form of breakouts. Owing to numerous random cracks inherent in the core, only 11 rectangular prismatic specimens (19×19×38 mm3) were successfully tested, employing the University of Wisconsin polyaxial cell. The two larger principal stresses, σ1 and σ2, were transmitted through metal pistons, while σ3 was applied by confining fluid pressure. Specimen sides facing σ3 were left 'unjacketed', i.e. in direct contact with the confining fluid, to simulate the condition of drilling-mud pressure applying the principal radial stress (σ3) to the exposed borehole wall. The loading path called for first bringing σ2 and σ3 to preset levels and then increasing σ1 at a constant strain rate (5x10-6/sec) until brittle failure occurred. Invariably, failure occurred at σ1 levels that were only about half as high as those in previously tested dry samples under the same σ2 and σ3 magnitudes. Instead of a shear fracture, or fault, steeply inclined in the direction of σ3, as previously observed in the dry specimens, brittle failure took the form of a localized cluster of through-going extensile cracks parallel and adjacent to the faces subjected to σ3. Since failure occurred at σ1 values close to those at dilatancy onset in dry specimens, we infer that as soon as microcracks reopened, confining fluid rushed into those daylighting at the σ3 faces and extended them along a path of least resistance, i.e. along a plane normal to σ3. Thus brittle failure under

  1. Summary and interpretation of dye-tracer tests to investigate the hydraulic connection of fractures at a ridge-and-valley-wall site near Fishtrap Lake, Pike County, Kentucky

    USGS Publications Warehouse

    Taylor, C.J.

    1994-01-01

    Dye-tracer tests were done during 1985-92 to investigate the hydraulic connection between fractures in Pennsylvanian coal-bearing strata at a ridge-and-valley-wall site near Fishtrap Lake, Pike County, Ky. Fluorescent dye was injected into a core hole penetrating near-surface and mining- induced fractures near the crest of the ridge. The rate and direction of migration of dye in the subsurface were determined by measuring the relative concentration of dye in water samples collected from piezometers completed in conductive fracture zones and fractured coal beds at various stratigraphic horizons within the ridge. Dye-concentration data and water-level measurements for each piezometer were plotted as curves on dye- recovery hydrographs. The dye-recovery hydrographs were used to evaluate trends in the fluctuation of dye concentrations and hydraulic heads in order to identify geologic and hydrologic factors affecting the subsurface transport of dye. The principal factors affecting the transport of dye in the subsurface hydrologic system were determined to be (1) the distribution, interconnection, and hydraulic properties of fractures; (2) hydraulic-head conditions in the near-fracture zone at the time of dye injection; and (3) subsequent short- and long-term fluctuations in recharge to the hydrologic system. In most of the dye-tracer tests, dye-recovery hydrographs are characterized by complex, multipeaked dye-concentration curves that are indicative of a splitting of dye flow as ground water moved through fractures. Intermittent dye pulses (distinct upward spikes in dye concentration) mark the arrivals of dye-labeled water to piezometers by way of discrete fracture-controlled flow paths that vary in length, complexity, and hydraulic conductivity. Dye injections made during relatively high- or increasing-head conditions resulted in rapid transport of dye (within several days or weeks) from near-surface fractures to piezometers. Injections made during relatively low- or

  2. The use of anatomically drop-shaped bioactive glass S53P4 implants in the reconstruction of orbital floor fractures--A prospective long-term follow-up study.

    PubMed

    Stoor, P; Mesimäki, Karri; Lindqvist, Christian; Kontio, Risto

    2015-07-01

    An isolated fracture of the orbital floor needs reconstruction if there is a clear herniation of adipose tissue or of the rectus inferior muscle into the maxillary sinus. A prospective study was carried out treating 20 patients with an isolated blow-out fracture of the orbital floor or with a combined zygomatico-orbito-maxillary complex fracture, using a newly designed anatomically drop-shaped implants made of bioactive glass (BAG) S53P4. Computed tomography (CT) was performed immediately postoperatively to confirm the correct position of the plate. The patients were followed up for an average of 32 months clinically and radiologically with magnetic resonance imaging (MRI) for an average of 31 months. None of the patients had any signs of complications related to the implant and the clinical outcome was very good. None of the patients had persisting diplopia. The level of the pupillas was normal in 15 of 20 patients. Minor hypo-ophthalmos ranging from 0.5 to 1.0 mm was observed in three patients, and moderate hypo-ophthalmos of 2.0 mm was seen in one patient. Hyperophthalmos of 1.0 mm was seen in one patient. Minor enophthalmos on the operated side ranging from 0.5 to 1.0 mm was seen in eight patients. Mild to moderate paraesthesia of the infraorbital nerve was observed in six patients. The immediate postoperative CT and the long term follow-up MRI revealed that the drop-shaped BAG implants retained their correct position in the orbital floor and did not show any evidence of losing their original shape or material resorption. No adverse tissue reaction was associated with the material. Due to the anatomical drop shape, the implants could successfully maintain the orbital volume and compensate for the retrobulbar adipose tissue atrophy. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  3. Discrete Fracture Network Characterization and Modeling in the Swedish Program for Nuclear Waste Disposal in Crystalline Rocks Using Information Acquired by Difference Flow Logging and Borehole Wall Image Logging

    NASA Astrophysics Data System (ADS)

    Follin, S.; Stigsson, M.; Levén, J.

    2006-12-01

    Difference flow logging is a relatively new hydraulic test method. It offers a superior geometrical resolution compared to the classic double-packer injection test method. Other significant features of the difference flow logging method are the long duration of the test period and the line source flow regime. These three features are vital for the characterization and the modeling of the conductive fracture frequency in crystalline rocks. Further, combining difference flow logging with core mapping and in situ borehole wall image logging (BIPS) allows for an enhanced geological cross correlation and structural interpretation. The data and analyses presented here come from the ongoing site investigations for a high-level nuclear waste repository in Forsmark managed by the Swedish Nuclear Fuel and Waste Management Co. First, we demonstrate the statistical properties of the fracture transmissivities acquired by difference flow logging for a number of one-kilometer-long cored boreholes. Secondly, we make a hydraulic comparison between these data and the transmissivities acquired by double-packer injection tests. Thirdly, we present a method for investigating the geometrical connectivity of open fractures in fracture network simulations and how this connectivity can be cross correlated to the fracture transmissivity distribution acquired by difference flow logging. Finally, we discuss the geometrical properties of flowing fractures as acquired by BIPS data and the correlation to the current stress situation in Forsmark. The geometrical anisotropy observed in the transmissivity data suggests that the current stress situation is very important for the flow field in Forsmark. This puts constraints on the collection and use of geological/structural data for hydrogeological discrete fracture network modeling.

  4. Clinical outcome following use of transconjunctival approach in reducing orbitozygomaticomaxillary complex fractures.

    PubMed

    Kumar, Saurabh; Shubhalaksmi, S

    2016-01-01

    The increasing emphasis on the open reduction and internal fixation of orbito-zygomatico-maxillary complex fractures has led to a more critical appraisal of the various surgical approaches to the orbital and zygomatic skeleton. Transconjunctival approach popularized by Tessier although credited to Bourquet in 1924 offer excellent exposure of the orbito-zygomatico-maxillary complex fracture especially the infra-orbital rim, frontozygomatic suture and the orbital floor. The argument against a transconjunctival access focuses primarily on concern about limited exposure that apparently makes accurate reduction and osteosynthesis of displaced fracture fragments difficult or impossible. Also, due to close association with eye and various ocular complications reported in the literature, most of the surgeons feel skeptical about using this approach. The aim of this study is to analyze the efficacy of transconjunctival approach in the treatment of orbito-zygomatico-maxillary complex fractures by evaluating the functional and esthetic results and its associated complications. We report a series of eight patients who have undergone fracture repair of the orbito-zygomatico-maxillary complex via a transconjunctival approach. Postoperative patient evaluation was performed with specific attention paid towards wound healing, functional stability, esthetic appearance and postoperative ocular complications. Postoperatively clinical examination along with radiographic examination was done to evaluate the position of the zygoma and determine the adequacy of fracture reduction. In all the patients excellent surgical exposure has been achieved for reduction and rigid fixation of the fracture fragments. None of the patients had any form of complication related to the approach. There were no postoperative ocular complications. Only one patient had postoperative chemosis which was transient and subsided subsequently. All the patients had excellent esthetic outcome, with symmetry of malar

  5. Evolution of the surgical approach to the orbitozygomatic fracture: From a subciliary to a transconjunctival and to a novel extended transconjunctival approach without skin incisions.

    PubMed

    Ishida, Kunihiro

    2016-04-01

    In the last 20 years, surgical approach to the orbitozygomatic fracture has evolved to limit skin incisions and minimize external scars. The treatment approach to the orbitozygomatic fracture was evaluated by a retrospective chart review from 1992 to 2012, and advantages, disadvantages, and complications were studied. Surgical approach to the orbitozygomatic fracture has evolved from a subciliary to a transconjunctival approach and to a novel extended transconjunctival approach without skin incisions in the last 20 years. The greatest advantage of using an extended transconjunctival approach is the wide exposure of the inferior orbital rim, orbital floor, lateral orbital wall, and the frontozygomatic suture in an unobstructed operative field without any skin incisions. Precise assessment of the reduction at the sphenozygomatic suture is possible with a wide exposure of the lateral orbital wall. As the dissection plane in a transconjunctival approach is entirely posterior to the lacrimal apparatus, the medial incision can be placed medially beyond the lacrimal punctum and by combining this approach with the transcaruncular approach, a wide operative field for the medial orbital wall can be obtained, which is the most advantageous point for choosing a transconjunctival approach over a subciliary approach. The complication rate was comparable to a subciliary approach. The author advocates an extended transconjunctival approach for orbitozygomatic fractures to avoid skin incisions and to precisely assess the reduction status. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  6. Diagnostic tools in maxillofacial fractures: Is there really a need of three-dimensional computed tomography?

    PubMed Central

    Shah, Sheerin; Uppal, Sanjeev K.; Mittal, Rajinder K.; Garg, Ramneesh; Saggar, Kavita; Dhawan, Rishi

    2016-01-01

    Introduction: Because of its functional and cosmetic importance, facial injuries, especially bony fractures are clinically very significant. Missed and maltreated fractures might result in malocclusion and disfigurement of the face, thus making accurate diagnosis of the fracture very essential. In earlier times, conventional radiography along with clinical examination played a major role in diagnosis of maxillofacial fractures. However, it was noted that the overlapping nature of bones and the inability to visualise soft tissue swelling and fracture displacement, especially in face, makes radiography less reliable and useful. Computed tomography (CT), also called as X-ray computed radiography, has helped in solving this problem. This clinical study is to compare three-dimensional (3D) CT reconstruction with conventional radiography in evaluating the maxillofacial fractures preoperatively and effecting the surgical management, accordingly. Materials and Methods: Fifty patients, with suspected maxillofacial fractures on clinical examination, were subjected to conventional radiography and CT face with 3D reconstruction. The number and site of fractures in zygoma, maxilla, mandible and nose, detected by both the methods, were enumerated and compared. The final bearing of these additional fractures, on the management protocol, was analysed. Results: CT proved superior to conventional radiography in diagnosing additional number of fractures in zygoma, maxilla, mandible (subcondylar) and nasal bone. Coronal and axial images were found to be significantly more diagnostic in fracture sites such as zygomaticomaxillary complex, orbital floor, arch, lateral maxillary wall and anterior maxillary wall. Conclusion: 3D images gave an inside out picture of the actual sites of fractures. It acted as mind's eye for pre-operative planning and intra-operative execution of surgery. Better surgical treatment could be given to 33% of the cases because of better diagnostic ability of CT

  7. Development and experimental evaluation of models for low capillary number two-phase flows in rough walled fractures relevant to natural gradient conditions

    SciTech Connect

    Glass, R.J.; Yarrington, L.; Nicholl, M.J.

    1997-09-01

    The major results from SNL`s Conceptual Model Development and Validation Task (WBS 1.2.5.4.6) as developed through exploration of small scale processes were synthesized in Glass et al. to give guidance to Performance Assessment on improving conceptual models for isothermal flow in unsaturated, fractured rock. There, pressure saturation and relative permeability curves for single fractures were proposed to be a function of both fracture orientation within the gravity field and initial conditions. We refer the reader to Glass et al. for a discussion of the implications of this behavior for Performance Assessment. The scientific research we report here substantiates this proposed behavior. We address the modeling of phase structure within fractures under natural gradient conditions relevant to unsaturated flow through fractures. This phase structure underlies the calculation of effective properties for individual fractures and hence fracture networks as required for Performance Assessment. Standard Percolation (SP) and Invasion Percolation (IP) approaches have been recently proposed to model the underlying phase saturation structures within the individual fractures during conditions of two-phase flow. Subsequent analysis of these structures yields effective two-phase pressure-saturation and relative permeability relations for the fracture. However, both of these approaches yield structures that are at odds with physical reality as we see in experiments and thus effective properties calculated from these structures are in error. Here we develop and evaluate a Modified Invasion Percolation (MIP) approach to better model quasi-static immiscible displacement in fractures. The effects of gravity, contact angle, local aperature field geometry, and local in-plane interfacial curvature between phases are included in the calculation of invasion pressure for individual sites in a discretized aperture field.

  8. Management of ocular, orbital, and adnexal trauma

    SciTech Connect

    Spoor, T.C.; Nesi, F.A.

    1988-01-01

    This book contains 20 chapters. Some of the chapter titles are: The Ruptured Globe: Primary Care; Corneal Trauma, Endophthalmitis; Antibiotic Usage; Radiology of Orbital Trauma; Maxillofacial Fractures; Orbital Infections; and Basic Management of Soft Tissue Injury.

  9. Fracture detection logging tool

    DOEpatents

    Benzing, William M.

    1992-06-09

    A method and apparatus by which fractured rock formations are identified and their orientation may be determined includes two orthogonal motion sensors which are used in conjunction with a downhole orbital vibrator. The downhole vibrator includes a device for orienting the sensors. The output of the sensors is displayed as a lissajou figure. The shape of the figure changes when a subsurface fracture is encountered in the borehole. The apparatus and method identifies fractures rock formations and enables the azimuthal orientation of the fractures to be determined.

  10. Skull fracture

    MedlinePlus

    ... may have been drinking alcohol or is otherwise impaired. Alternative Names Basilar skull fracture; Depressed skull fracture; Linear skull fracture Images Skull of an adult Skull fracture Skull fracture ...

  11. Fracture patterns in the maxillofacial region: a four-year retrospective study

    PubMed Central

    2015-01-01

    Objectives The facial bones are the most noticeable area in the human body, and facial injuries can cause significant functional, aesthetic, and psychological complications. Continuous study of the patterns of facial bone fractures and changes in trends is helpful in the prevention and treatment of maxillofacial fractures. The purpose of the current clinico-statistical study is to investigate the pattern of facial fractures over a 4-year period. Materials and Methods A retrospective analysis of 1,824 fracture sites was carried out in 1,284 patients admitted to SMG-SNU Boramae Medical Center for facial bone fracture from January 2010 to December 2013. We evaluated the distributions of age/gender/season, fracture site, cause of injury, duration from injury to treatment, hospitalization period, and postoperative complications. Results The ratio of men to women was 3.2:1. Most fractures occurred in individuals aged between teens to 40s and were most prevalent at the middle and end of the month. Fractures occurred in the nasal bone (65.0%), orbital wall (29.2%), maxillary wall (15.3%), zygomatic arch (13.2%), zygomaticomaxillary complex (9.8%), mandibular symphysis (6.5%), mandibular angle (5.9%), mandibular condyle (4.9%), and mandibular body (1.9%). The most common etiologies were fall (32.5%) and assault (26.0%). The average duration of injury to treatment was 6 days, and the average hospitalization period was 5 days. Eighteen postoperative complications were observed in 17 patients, mainly infection and malocclusion in the mandible. Conclusion This study reflects the tendency for trauma in the Seoul metropolitan region because it analyzes all facial fracture patients who visited our hospital regardless of the specific department. Distinctively, in this study, midfacial fractures had a much higher incidence than mandible fractures. PMID:26734557

  12. Subciliary versus swinging eyelid approach to the orbital floor.

    PubMed

    De Riu, Giacomo; Meloni, Silvio Mario; Gobbi, Roberta; Soma, Damiano; Baj, Alessandro; Tullio, Antonio

    2008-12-01

    In this retrospective study, the authors compare the outcomes of two different approaches to the orbital floor: the classic subciliary versus the transconjunctival plus lateral canthotomy (swinging eyelid). Forty-five patients who underwent orbital surgery (47 approaches) for different indications (orbital fractures, correction of Grave's exophthalmos, tumours of the internal orbit and correction of enophthalmos in secondary trauma) were placed in two groups, depending on the approach. The long-term effects of the incisions, the outcome of the approach and the complications were recorded and compared. The minimum follow-up for inclusion in the study was 1 year. Twenty-three orbits underwent subciliary incision, and 24 underwent swinging eyelid. No ectropion or entropion was seen in any patient. For the swinging eyelid approach, complications included three cases (12.5%) of canthal malposition; for the subciliary approach, five cases (21.14%) of lagophthalmos and 10 visible scars were observed. Our findings show the advantages of the swinging eyelid: better aesthetic results, the same or greater exposure of the orbital floor and the caudal part of the lateral and medial walls, shorter surgical time (sutureless) and a less extended scar. Although in our experience this approach is preferable in orbital surgery, some indications for the subciliary still remain.

  13. Efficacy of Iliac Crest vs. Medpor in Orbital Floor Reconstruction.

    PubMed

    Ram, Hari; Singh, R K; Mohammad, Shadab; Gupta, Anup Kumar

    2010-06-01

    The present study is to compare the effectiveness of iliac crest graft and medpor implant, for repairing traumatic orbital floor defects. A total of 20 patients were included in the study. Autogenous iliac crest graft and medpor implant was used in 10 patients of the each group. Patients were evaluated for the presence or absence of diplopia, enophthalmos, infraorbital nerve paresthesia, and ocular motility disorders. Surgical indications for orbital exploration included entrapment of orbital tissues, large orbital defect (greater than 50% of the orbital floor or more than 8 mm), or orbital floor defects with involvement of other zygomaticofrontal complex fractures. All patients were successfully treated by restoration of the orbital wall continuity. Follow-up was done at 1-12 weeks. One patient had postoperative infection. There was no graft extrusion. Both the groups showed satisfactory results, but group II was better than group I, as there was no donor site morbidity. Porous polyethylene (Medpor) is a biocompatible and high-density polyethylene implant. It is well tolerated by surrounding tissue, and its porous structure is rapidly infiltrated by host tissue. It is a highly stable and somewhat flexible porous alloplast that has rapid tissue in growth into its pores.

  14. Sino-orbital fistula: two case reports.

    PubMed

    McNab, A A

    2000-08-01

    A fistula between the paranasal sinuses and the orbit as a late complication of orbital fractures is rare and may present with intermittent symptoms due to air passing into the orbit. A case note review of two patients with sino-orbital fistula is presented. Two patients, 23- and 30-year-old males, presented with intermittent symptoms of globe displacement, diplopia or discomfort months after repair of an orbital floor fracture with a synthetic orbital floor implant. The symptoms occurred after nose blowing. They were both cured by removal of the implant and partial removal of the tissue surrounding the implant. A sino-orbital fistula may complicate the otherwise routine repair of an orbital floor fracture, but may be cured by removal of the implant and part of the surrounding pseudocapsule.

  15. Economics of facial fracture reductions in the United States over 12 months.

    PubMed

    Nalliah, Romesh P; Allareddy, Veeratrishul; Kim, Min Kyeong; Venugopalan, Shankar R; Gajendrareddy, Praveenkumar; Allareddy, Veerasathpurush

    2013-04-01

    The face is a complex architectural structure in the body and is a high-risk site for fractures. Hospitalization is necessary for adequate treatment. The objective of this study is to examine hospitalization outcomes associated with reduction in facial fractures in the United States. The Nationwide Inpatient Sample (NIS) of the health care cost and utilization project for 2008 was used. This database provides weighted estimates of all hospitalizations in the United States, which approximates 39.88 million admissions in the entire United States. Hospital discharges with primary procedure ICD-9-CM codes for reduction in facial fractures were selected. Outcomes examined included hospitalization charges, length of stay, and causes of injuries. All estimates obtained from the sample were projected to national levels. Reduction in facial fractures was performed as primary procedure in 21,244 hospitalizations. The total hospitalization charges were about $1.06 billion, and total hospitalization days was 93,808. About 80% of all hospitalizations occurred among men. The frequently occurring external causes of injuries leading to hospitalization for reduction in facial fractures include assault (36.5% of all hospitalizations), motor vehicle traffic accidents (16%), falls (15%), and other transportation accidents (3.5%). The frequently performed procedures were open reduction in mandibular fractures (52.2%), open reduction in facial fractures including those of orbital rim or wall (14.7%), closed reduction in mandibular fractures (12.1%), and open reduction in malar and zygomatic fractures (11.8%). National hospitalization outcomes related to reduction in facial fractures indicate an extensive consumption of hospital resources. If hospital emergency room protocols and inpatient protocols relating to the most expensive fractures and longest hospital stays that we have identified can improve, this may lead to improved outcomes and a reduction in hospital charges for facial

  16. In vitro fatigue-crack growth and fracture toughness behavior of thin-walled superelastic Nitinol tube for endovascular stents: A basis for defining the effect of crack-like defects.

    PubMed

    Robertson, Scott W; Ritchie, Robert O

    2007-02-01

    Endovascular stents made of the superelastic nickel-titanium alloy Nitinol are subjected in service to tens of millions of loading cycles and even "single-event" overloads, both of which can potentially result in fracture and/or complete failure of the device. A fracture-mechanics-based methodology can provide a means to quantify relevant material parameters critical to the design against such failures. However, there is a dearth of relevant experimental data in the literature on such fracture-mechanics-based approaches to fatigue in Nitinol; furthermore, that which does exist invariably pertains to product forms that are not appropriate for stent manufacture, e.g., bulk Nitinol bar and strip. Consequently, the current work is focused on characterizing in vitro both subcritical and critical crack growth (fatigue-crack growth and R-curve fracture toughness) behavior in thin-walled ( approximately 400microm thick) Nitinol tubing similar to that used for medical device manufacture (following shape-setting procedures to flatten the material), with a resultant austenite finish temperature of A(f) approximately 25-30 degrees C, identical to self-expanding Nitinol stents. Fatigue-crack growth behavior, measured in Hanks' Balanced Saline Solution over a wide spectrum of growth rates (down to 10(-10)m/cycle) and at a range of positive load ratios (R=0.1-0.7), revealed significantly higher fatigue thresholds than had been previously reported for bulk Nitinol material. In addition, we examine the critical effect of test frequency, as most fatigue experiments on Nitinol have been performed at 30Hz or above, despite the fact that this is far in excess of the frequency of physiological loading. Finally, the fracture toughness properties are characterized in thin-section Nitinol and show marked crack-resistance (R-curve) behavior with a dependence on crack-growth angle (with respect to the tube drawing axis); additionally, measured toughnesses are found to be lower than has been

  17. Need for airbag and seatbelt to reduce orbital injuries from steering wheel knob.

    PubMed

    Hwang, Kun; Kim, Joo Ho

    2014-11-01

    The aims of this study are to report a blowout fracture of the orbital floor and medial wall caused by being struck by a steering wheel knob of an automobile and to discuss the use of airbags and seatbelts as a preventive measure for orbital injuries. A 58-year-old man was struck in the left eye by a steering wheel. His car hit a telephone pole, and he had a frontal collision injury. In this frontal impact, his left eye was hit by a Brodie knob attached to the steering wheel. At the time of injury, the speed of the car was about 65 km/h. He was not wearing a seatbelt, and the airbag had not deployed. Swelling and ecchymosis were observed at the left periorbital area, and he had diplopia on a left-side gaze. A CT revealed fractures in the medial and inferior wall of the left orbit. Entrapped soft tissues were reduced, and the medial wall and floor were reconstructed with a resorbable sheet. His diplopia disappeared 12 days after surgery. To prevent the injury from the steering wheel knob, an airbag should be installed in any vehicle, which has a steering wheel knob. Legislation mandating the use of airbags as well as seatbelts in vehicles with attached steering wheel knobs should be made.

  18. Congenital Orbital Teratoma.

    PubMed

    Pellerano, Fernando; Guillermo, Elvis; Garrido, Gloreley; Berges, Pedro

    2017-01-01

    We report a case of congenital orbital teratoma. A 3-day-old male, born at 39 weeks' gestation without relevant prenatal history, presented with a large vascularized proptotic mass distorting the left midface. Laboratory studies showed elevated serum alpha-fetoprotein (12,910 ng/ml). Computed tomography showed a multiloculated heterogeneous lesion composed of hypodense and hyperdense calcified areas encompassing the whole orbital cavity with expansion of the bony walls, as well as forward displacement and compression of the eyeball without extension to surrounding structures. Clinical, imaging and laboratory features were consistent with congenital orbital teratoma. Due to pronounced proptosis with exposure keratopathy and corneal perforation, no motility of the globe and no vision in the affected eye in a resource-limited setting, the patient underwent orbital exenteration. Histopathological examination confirmed the diagnosis of mature cystic teratoma. We describe the clinical course, radiographic and histopathological findings of this rare orbital tumor.

  19. Congenital Orbital Teratoma

    PubMed Central

    Pellerano, Fernando; Guillermo, Elvis; Garrido, Gloreley; Berges, Pedro

    2017-01-01

    We report a case of congenital orbital teratoma. A 3-day-old male, born at 39 weeks’ gestation without relevant prenatal history, presented with a large vascularized proptotic mass distorting the left midface. Laboratory studies showed elevated serum alpha-fetoprotein (12,910 ng/ml). Computed tomography showed a multiloculated heterogeneous lesion composed of hypodense and hyperdense calcified areas encompassing the whole orbital cavity with expansion of the bony walls, as well as forward displacement and compression of the eyeball without extension to surrounding structures. Clinical, imaging and laboratory features were consistent with congenital orbital teratoma. Due to pronounced proptosis with exposure keratopathy and corneal perforation, no motility of the globe and no vision in the affected eye in a resource-limited setting, the patient underwent orbital exenteration. Histopathological examination confirmed the diagnosis of mature cystic teratoma. We describe the clinical course, radiographic and histopathological findings of this rare orbital tumor. PMID:28275597

  20. Gullies on the Wall of an Unnamed Crater in Utopia Planitia

    NASA Image and Video Library

    2015-07-29

    This enhanced-color image from NASA Mars Reconnaissance Orbiter shows gullies in the northern wall of an unnamed crater in Utopia Planitia. The banked, sinuous shape of the gully channels suggest that water was involved in their formation. The source of this water however is a subject of debate. Hypotheses include melting of snow or near-surface ground ice. Other features also suggest the past (and possibly present) presence of snow or ground ice in this region. For example, the "mantle" deposit on the crater wall displays polygonal fractures. Polygons on Earth are associated with periglacial activity. This refers to processes that occur from the presence of ground ice, which interacts with surface and subsurface materials, as well as the Martian atmosphere as a function of climate and seasons). The mantle itself may be the remains of a dusty snowpack deposited in Mars' recent past. At the base of the mantle are fractures associated with the slumping of these deposits under their own weight and Martian gravity. The largest gullies cut into these mantling deposits, and in some places obscure the underlying fractures at the base of the crater wall. This indicates that the largest gullies are younger than both the mantle and the fractures. http://photojournal.jpl.nasa.gov/catalog/PIA19862

  1. The globe and orbit in Laron syndrome.

    PubMed

    Kornreich, L; Konen, O; Lilos, P; Laron, Z

    2011-09-01

    Patients with LS have an inborn growth hormone resistance, resulting in failure to generate IGF-1. The purpose of this study was to evaluate the size of the eye and orbit in LS. We retrospectively reviewed the MR imaging of the brain in 9 patients with LS for the following parameters: axial diameter of the globe, interzygomatic distance, perpendicular distance from the interzygomatic line to margins of the globe, medial-to-lateral diameter of the orbit at the anterior orbital rim, distance from the anterior orbital rim to the anterior globe, maximal distance between the medial walls of the orbits, lateral orbital wall angle, lateral orbital wall length, and mediolateral thickness of the intraorbital fat in the most cranial image of the orbit. All measurements were made bilaterally. Twenty patients referred for MR imaging for unrelated reasons served as control subjects. Compared with the control group, the patients with LS had a significantly smaller maximal globe diameter and shallower but wider orbits due to a shorter lateral wall, a smaller medial distance between the orbits, and a larger angle of the orbit. The ratio between the most anterior orbital diameter and the globe was greater than that in controls. The position of the globe was more anterior in relation to the interzygomatic line. Shallow and wide orbits and small globes relative to orbital size are seen in LS and may be secondary to IGF-1 deficiency.

  2. Stress Fractures

    MedlinePlus

    Stress fractures Overview By Mayo Clinic Staff Stress fractures are tiny cracks in a bone. They're caused by ... up and down or running long distances. Stress fractures can also arise from normal use of a ...

  3. Greenstick Fractures

    MedlinePlus

    Greenstick fractures Overview By Mayo Clinic Staff A greenstick fracture occurs when a bone bends and cracks, instead of breaking completely into separate pieces. The fracture looks similar to what happens when you try ...

  4. Relative permeability through fractures

    SciTech Connect

    Diomampo, Gracel, P.

    2001-08-01

    The mechanism of two-phase flow through fractures is of importance in understanding many geologic processes. Currently, two-phase flow through fractures is still poorly understood. In this study, nitrogen-water experiments were done on both smooth and rough parallel plates to determine the governing flow mechanism for fractures and the appropriate methodology for data analysis. The experiments were done using a glass plate to allow visualization of flow. Digital video recording allowed instantaneous measurement of pressure, flow rate and saturation. Saturation was computed using image analysis techniques. The experiments showed that gas and liquid phases flow through fractures in nonuniform separate channels. The localized channels change with time as each phase path undergoes continues breaking and reforming due to invasion of the other phase. The stability of the phase paths is dependent on liquid and gas flow rate ratio. This mechanism holds true for over a range of saturation for both smooth and rough fractures. In imbibition for rough-walled fractures, another mechanism similar to wave-like flow in pipes was also observed. The data from the experiments were analyzed using Darcy's law and using the concept of friction factor and equivalent Reynold's number for two-phase flow. For both smooth- and rough-walled fractures a clear relationship between relative permeability and saturation was seen. The calculated relative permeability curves follow Corey-type behavior and can be modeled using Honarpour expressions. The sum of the relative permeabilities is not equal one, indicating phase interference. The equivalent homogeneous single-phase approach did not give satisfactory representation of flow through fractures. The graphs of experimentally derived friction factor with the modified Reynolds number do not reveal a distinctive linear relationship.

  5. Fracture toughness design in horse hoof keratin.

    PubMed

    Bertram, J E; Gosline, J M

    1986-09-01

    An engineering fracture mechanics approach was applied to the analysis of the fracture resistance of equine hoof-wall. The relationship between fracture toughness and the morphological organization of the keratin hoof tissue was investigated. Fracture toughness was evaluated using the J-integral analysis method which employs the compact tension test geometry. Tensile tests were also conducted to evaluate the effect of the morphological organization on the stress-strain behaviour. Hoof-wall has greatest fracture resistance for cracks running proximally, parallel to the tubular component of the wall keratin. For fully hydrated material tested in this direction the mean critical J-integral value at failure was 1.19 X 10(4)J m-2. This was nearly three times greater than the value determined for the weakest orientation, in which the crack ran parallel to the material between the tubules. The lower fracture toughness of the intertubular material dominates the fracture behaviour of this tissue. The tubular components of the wall appear to reinforce against fracture along the weak plane and the entire wall organization provides the mechanical capability for limiting and controlling fracture in this tissue.

  6. [The adipose tissue of the orbit. Anatomic classification, therapeutic deductions].

    PubMed

    Gola, R; Carreau, J P; Faissal, A

    1995-01-01

    There are two types of adipose tissue in the orbit. The yellow fat and the more abundant white, or orbital fat. Orbital fat cannot be dissociated from the contents of the orbit and plays an important role in ocular physiology and oculomotricity. Orbital fat is essential for aesthetic orbits. Graves' disease and anophthalmia. Adipose tissue in the orbit is particularly important in protecting the ocular globe from lateral wall trauma.

  7. A novel classification of frontal bone fractures: The prognostic significance of vertical fracture trajectory and skull base extension.

    PubMed

    Garg, Ravi K; Afifi, Ahmed M; Gassner, Jennifer; Hartman, Michael J; Leverson, Glen; King, Timothy W; Bentz, Michael L; Gentry, Lindell R

    2015-05-01

    The broad spectrum of frontal bone fractures, including those with orbital and skull base extension, is poorly understood. We propose a novel classification scheme for frontal bone fractures. Maxillofacial CT scans of trauma patients were reviewed over a five year period, and frontal bone fractures were classified: Type 1: Frontal sinus fracture without vertical extension. Type 2: Vertical fracture through the orbit without frontal sinus involvement. Type 3: Vertical fracture through the frontal sinus without orbit involvement. Type 4: Vertical fracture through the frontal sinus and ipsilateral orbit. Type 5: Vertical fracture through the frontal sinus and contralateral or bilateral orbits. We also identified the depth of skull base extension, and performed a chart review to identify associated complications. 149 frontal bone fractures, including 51 non-vertical frontal sinus (Type 1, 34.2%) and 98 vertical (Types 2-5, 65.8%) fractures were identified. Vertical fractures penetrated the middle or posterior cranial fossa significantly more often than non-vertical fractures (62.2 v. 15.7%, p = 0.0001) and had a significantly higher mortality rate (18.4 v. 0%, p < 0.05). Vertical fractures with frontal sinus and orbital extension, and fractures that penetrated the middle or posterior cranial fossa had the strongest association with intracranial injuries, optic neuropathy, disability, and death (p < 0.05). Vertical frontal bone fractures carry a worse prognosis than frontal bone fractures without a vertical pattern. In addition, vertical fractures with extension into the frontal sinus and orbit, or with extension into the middle or posterior cranial fossa have the highest complication rate and mortality. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  8. Clinical outcome following use of transconjunctival approach in reducing orbitozygomaticomaxillary complex fractures

    PubMed Central

    Kumar, Saurabh; Shubhalaksmi, S.

    2016-01-01

    Background: The increasing emphasis on the open reduction and internal fixation of orbito-zygomatico-maxillary complex fractures has led to a more critical appraisal of the various surgical approaches to the orbital and zygomatic skeleton. Transconjunctival approach popularized by Tessier although credited to Bourquet in 1924 offer excellent exposure of the orbito-zygomatico-maxillary complex fracture especially the infra-orbital rim, frontozygomatic suture and the orbital floor. The argument against a transconjunctival access focuses primarily on concern about limited exposure that apparently makes accurate reduction and osteosynthesis of displaced fracture fragments difficult or impossible. Also, due to close association with eye and various ocular complications reported in the literature, most of the surgeons feel skeptical about using this approach. Aim: The aim of this study is to analyze the efficacy of transconjunctival approach in the treatment of orbito-zygomatico-maxillary complex fractures by evaluating the functional and esthetic results and its associated complications. Material and Method: We report a series of eight patients who have undergone fracture repair of the orbito-zygomatico-maxillary complex via a transconjunctival approach. Postoperative patient evaluation was performed with specific attention paid towards wound healing, functional stability, esthetic appearance and postoperative ocular complications. Postoperatively clinical examination along with radiographic examination was done to evaluate the position of the zygoma and determine the adequacy of fracture reduction. Results: In all the patients excellent surgical exposure has been achieved for reduction and rigid fixation of the fracture fragments. None of the patients had any form of complication related to the approach. There were no postoperative ocular complications. Only one patient had postoperative chemosis which was transient and subsided subsequently. All the patients had

  9. Periprosthetic fractures of the acetabulum.

    PubMed

    Helfet, David L; Ali, Arif

    2004-01-01

    Periprosthetic fractures of the acetabulum after total hip arthroplasty are uncommon, but are increasing in number and severity. These fractures may occur intraoperatively, during the perioperative period, or many years after the total hip arthroplasty. Periprosthetic fractures of the acetabulum vary in severity and may involve stress fractures of the pubis or medial wall, significant bone loss secondary to osteolysis and subsequent loss of column integrity, or complete pelvic discontinuity. Treatment differs depending on the complexity of the fracture and the stability of the acetabular prosthesis. Surgical treatment for an unstable acetabulum should stabilize the bony columns of the acetabulum, provide bone grafting of defects, and should maintain adequate bone stock for replacement of a stable acetabular implant. Strict adherence to the principles of fracture surgery is required to achieve bony union of the acetabular columns and provide a stable environment for reimplantation of an acetabular component.

  10. Orbital metastatic osteosarcoma.

    PubMed

    Rajabi, Mohammad Taher; Saeedi-Anari, Ghasem; Ramezani, Farshid; Tabatabaie, Seyed-Ziaeddin; Rajabi, Mohammad Bagher; Asadi Amoli, Fahimeh

    2015-02-01

    At an estimated incidence of 2 cases per million persons per year, osteosarcoma is the most common primary malignant bone tumor in children and adults, excluding hematopoietic intraosseous tumors. Orbital metastases of osteosarcoma are very rare. Only 5 cases of orbital metastasis of osteosarcoma previously reported in the literature. We report the case of a 19-year-old man with known history of osteosarcoma of right distal femur who presented with acute visual loss and progressive protrusion of his left eye. Orbital CT scan and MRI revealed orbital mass eroding orbital walls and intracranial invasion. He underwent superotemporal orbitotomy for debulking of orbital mass. Histopathological examination (HPE) of the specimen was reported as metastatic osteosarcoma with extensive tumor necrosis. Then he underwent adjuvant chemotherapy and palliative radiotherapy. Although orbital metastasis of osteosarcoma is a rare event, it seems it has had an increasing trend recently. so, making efforts to palliate the patient's symptoms by multidisciplinary teamwork and proper interaction among ophthalmologist, orthopedic surgeons and oncologists is necessary.

  11. Chest Wall Trauma.

    PubMed

    Majercik, Sarah; Pieracci, Fredric M

    2017-05-01

    Chest wall trauma is common, and contributes significantly to morbidity and mortality of trauma patients. Early identification of major chest wall and concomitant intrathoracic injuries is critical. Generalized management of multiple rib fractures and flail chest consists of adequate pain control (including locoregional modalities); management of pulmonary dysfunction by invasive and noninvasive means; and, in some cases, surgical fixation. Multiple studies have shown that patients with flail chest have substantial benefit (decreased ventilator and intensive care unit days, improved pulmonary function, and improved long-term functional outcome) when they undergo surgery compared with nonoperative management. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Passive orbital disconnect strut

    NASA Technical Reports Server (NTRS)

    Parmley, R. T.; Kittel, P.

    1984-01-01

    The design and test results with a third generation passive orbital disconnect strut (PODS) for space-based cryogenic He dewars are presented. Three pairs of PODS struts support a tank and change lengths in response to gas and temperature changes. A thin wall fiberglass tube is used on the cold disconnect end, which can be operated on the ground or in space. Tests were performed to characterize heat flows across the cold end to a liquid He sink and subsequent vacuum pressure within the He tank. Heat transfer was lower than predicted, suggesting that longer dewar in-orbit lifetimes can be expected with the new PODS.

  13. All Along the Fractures

    NASA Image and Video Library

    2015-09-30

    This image from NASA Mars Reconnaissance Orbiter spacecraft provides information about erosion and movement of surface material, about wind and weather patterns, even about the soil grains and grain sizes. However, looking past the dunes, these images also reveal the nature of the substrate beneath. Within the spaces between the dunes, a resistant and highly fractured surface is revealed. The fractured ground is resistant to erosion by the wind, and suggests the material is bedrock that is now shattered by a history of bending stresses or temperature changes, such as cooling, for example. Alternately, the surface may be a sedimentary layer that was once wet and shrunk and fractured as it dried, like gigantic mud cracks. In either case, the relative small and indistinct fractures have trapped the dark dune sand marching overhead. Now the fractures have become quite distinct, allowing us to examine the orientation and spacing of the fractures to learn more about the processes that formed them. http://photojournal.jpl.nasa.gov/catalog/PIA19958

  14. Kepler's Orbit

    NASA Image and Video Library

    Kepler does not orbit the Earth, rather it orbits the Sun in concert with the Earth, slowly drifting away from Earth. Every 61 Earth years, Kepler and Earth will pass by each other. Throughout the ...

  15. Orbital cellulitis

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/001012.htm Orbital cellulitis To use the sharing features on this page, please enable JavaScript. Orbital cellulitis is an infection of the fat and muscles ...

  16. [Atlas fractures].

    PubMed

    Schären, S; Jeanneret, B

    1999-05-01

    Fractures of the atlas account for 1-2% of all vertebral fractures. We divide atlas fractures into 5 groups: isolated fractures of the anterior arch of the atlas, isolated fractures of the posterior arch, combined fractures of the anterior and posterior arch (so-called Jefferson fractures), isolated fractures of the lateral mass and fractures of the transverse process. Isolated fractures of the anterior or posterior arch are benign and are treated conservatively with a soft collar until the neck pain has disappeared. Jefferson fractures are divided into stable and unstable fracture depending on the integrity of the transverse ligament. Stable Jefferson fractures are treated conservatively with good outcome while unstable Jefferson fractures are probably best treated operatively with a posterior atlanto-axial or occipito-axial stabilization and fusion. The authors preferred treatment modality is the immediate open reduction of the dislocated lateral masses combined with a stabilization in the reduced position using a transarticular screw fixation C1/C2 according to Magerl. This has the advantage of saving the atlanto-occipital joints and offering an immediate stability which makes immobilization in an halo or Minerva cast superfluous. In late instabilities C1/2 with incongruency of the lateral masses occurring after primary conservative treatment, an occipito-cervical fusion is indicated. Isolated fractures of the lateral masses are very rare and may, if the lateral mass is totally destroyed, be a reason for an occipito-cervical fusion. Fractures of the transverse processes may be the cause for a thrombosis of the vertebral artery. No treatment is necessary for the fracture itself.

  17. Pressureless Orbital Decompression for Myopic Proptosis.

    PubMed

    Rajak, Saul N; McGovern, Richard A; Selva, Dinesh

    2017-01-01

    Orbital decompression surgery increases the orbital volume. It has rarely been used for proptosis of the large highly myopic globe. However, external decompression surgery carries significant risks because of the large thin-walled globe. The authors report the first use of endoscopic medial wall orbital decompression surgery in this setting to obviate the risk of globe pressure.Endoscopic medial wall decompression brought about a 4 mm reduction of proptosis, correction of exotropia and elimination of retrobulbar ache providing good symmetry with the fellow eye.Endoscopic medial wall orbital decompression can be very effective for correcting the proptosis of high myopia and minimizes the risk of damage to the very large, thin-walled globe.

  18. The mechanism of fracture

    SciTech Connect

    Goel, V.S.

    1986-01-01

    In this book eighty-five papers look at fractures. Topics covered are fracture mechanics, fracture mechanisms, evaluating fracture resistance, fracture toughness, predicting crack growth, surface cracking, crack initiation and propagation, weld fractures, engineering applications of fracture mechanics, fracture and failure in nonmetallic materials, dynamic fractures, test techniques, radiation embrittlement, applications of fracture mechanics, design concepts, and creep.

  19. Fiber-Laden Proppant Placement in a Deformable Fracture: Influence of Fracture-Surface Roughness

    NASA Astrophysics Data System (ADS)

    Medina, R.; Detwiler, R. L.; Prioul, R.; Xu, W.; Ortega, J. A.

    2016-12-01

    During the shut-in stage of hydraulic fracturing, aperture decreases and proppant is trapped between the fracture walls. The amount and distribution of the trapped proppant determines the fracture permeability after fracture closure. Conventional fluids used in hydraulic fracturing typically form a uniform distribution of proppant within the fracture, i.e. proppant pack, and the fracture permeability is that of the proppant pack. In recent experiments, the addition of fibers to proppant mixtures has been shown to result in the formation of proppant-fiber islands surrounded by solids-free regions. The formation of such proppant-fiber islands has the potential to increase fracture permeability, however, the behavior of these islands when subjected to an applied stress is unknown. We present preliminary results from a series of experiments of fiber-proppant settling inside a deformable fracture with both smooth and rough walls. The experimental system consists of a 15cm x 15cm fracture cell that allows the direct application of a normal stress to the fracture surfaces while the entire flow field is imaged using a high-resolution CCD camera. The proppant mixture was prepared by adding 17.7% v/v of quartz sand and 0.4% v/v of polymeric fibers to a highly shear-thinning viscous fluid (0.48% w/w guar-water). The proppant mixture was injected into the fracture and allowed to settle uninterrupted for two hours before we incrementally increased the normal stress applied to the fracture surfaces from 0 to 90 kPa. The results for both smooth- and rough-walled fractures demonstrate the development of isolated proppant-fiber islands with some interconnected proppant-free regions. In the smooth-walled fracture, the isolated proppant islands settled towards the bottom of the fracture that resulted in some consolidation of the proppant mixture in the lower portion of the fracture. The proppant islands in the rough-walled fracture show a reduced amount of settling, resulting in

  20. Stress Fractures

    MedlinePlus

    Stress fractures Overview Stress fractures are tiny cracks in a bone. They're caused by repetitive force, often from overuse — such as repeatedly jumping up and down or running long distances. Stress fractures can also arise from normal use of ...

  1. Novel Surgical Approaches to the Orbit

    PubMed Central

    Campbell, Ashley A.; Grob, Seanna R.; Yoon, Michael K.

    2015-01-01

    Determining safe surgical access to the orbit can be difficult given the complex anatomy and delicacy of the orbital structures. When considering biopsy or removal of an orbital tumor or repair of orbital fractures, careful planning is required to determine the ideal approach. Traditionally, this has at times necessitated invasive procedures with large incisions and extensive bone removal. The purpose of this review was to present newly techniques and devices in orbital surgery that have been reported over the past decade, with aims to provide better exposure and/or minimally invasive approaches and to improve morbidity and/or mortality. PMID:26692713

  2. Novel Surgical Approaches to the Orbit.

    PubMed

    Campbell, Ashley A; Grob, Seanna R; Yoon, Michael K

    2015-01-01

    Determining safe surgical access to the orbit can be difficult given the complex anatomy and delicacy of the orbital structures. When considering biopsy or removal of an orbital tumor or repair of orbital fractures, careful planning is required to determine the ideal approach. Traditionally, this has at times necessitated invasive procedures with large incisions and extensive bone removal. The purpose of this review was to present newly techniques and devices in orbital surgery that have been reported over the past decade, with aims to provide better exposure and/or minimally invasive approaches and to improve morbidity and/or mortality.

  3. Patterns of Fracture and Tidal Stresses Due to Nonsynchronous Rotation: Implications for Fracturing on Europa

    NASA Technical Reports Server (NTRS)

    Parmentier, E. M.; Helfenstein, P.

    1985-01-01

    Global lineaments on Europa were interpreted as fractures in an icy crust. A variety of lineament types were identified, which appear to form a systematic pattern on the surface. For a synchronously rotating body, the patterns of fractures observed could be produced by a combination of stresses due to orbital recession, orbital eccentricity, and internal contraction. However, it was recently suggested that the forced eccentricity of Europa's orbit may result in nonsynchronous rotation. The hypothesis that fractures in a thin icy crust may have formed in response to stresses resulting from nonsynchronous rotation is studied.

  4. Patterns of fracture and tidal stresses due to nonsynchronous rotation: Implications for fracturing on Europa

    NASA Astrophysics Data System (ADS)

    Parmentier, E. M.; Helfenstein, P.

    1985-04-01

    Global lineaments on Europa were interpreted as fractures in an icy crust. A variety of lineament types were identified, which appear to form a systematic pattern on the surface. For a synchronously rotating body, the patterns of fractures observed could be produced by a combination of stresses due to orbital recession, orbital eccentricity, and internal contraction. However, it was recently suggested that the forced eccentricity of Europa's orbit may result in nonsynchronous rotation. The hypothesis that fractures in a thin icy crust may have formed in response to stresses resulting from nonsynchronous rotation is studied.

  5. Gullies in Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-388, 11 June 2003

    Many craters and troughs at polar and middle latitudes on Mars have gullies carved in their walls. These gullies may have formed by running water; others have suggested alternative, exotic fluids such as liquid or gaseous carbon dioxide. This view of martian gullies was acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). The image shows gullies in the wall of an old meteor impact crater near 39.0oS, 200.7oW. Sunlight illuminates the scene from the upper left.

  6. Gullied Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-371, 25 May 2003

    Gullies are common in some regions on middle- and polar-latitude slopes, such as crater walls. This March 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies on the north wall of a crater in the Atlantis Chaos region near 34.3oS, 178.0oW. The gullies might have formed by flow of a fluid--perhaps liquid water--sometime in the geologically recent martian past. Sunlight illuminates the scene from the upper left.

  7. Gullies in Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-388, 11 June 2003

    Many craters and troughs at polar and middle latitudes on Mars have gullies carved in their walls. These gullies may have formed by running water; others have suggested alternative, exotic fluids such as liquid or gaseous carbon dioxide. This view of martian gullies was acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). The image shows gullies in the wall of an old meteor impact crater near 39.0oS, 200.7oW. Sunlight illuminates the scene from the upper left.

  8. Gullied Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-371, 25 May 2003

    Gullies are common in some regions on middle- and polar-latitude slopes, such as crater walls. This March 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies on the north wall of a crater in the Atlantis Chaos region near 34.3oS, 178.0oW. The gullies might have formed by flow of a fluid--perhaps liquid water--sometime in the geologically recent martian past. Sunlight illuminates the scene from the upper left.

  9. Wall turbulence without walls

    NASA Astrophysics Data System (ADS)

    Mizuno, Yoshinori; Jimenez, Javier

    2008-11-01

    Direct numerical simulations are presented of isolated logarithmic layers without an underlying buffer zone. They are implemented by enforcing artificial boundary conditions within the logarithmic layer which are synthesized from values from the interior of the flow. As an example, simulations of a half-channel employing this technique are discussed. The results exhibit logarithmic mean velocity profiles, and velocity fluctuation intensities that are similar to those obtained by the full DNS of half or full channels. Those results strongly suggest that the formation of a logarithmic layer is not overly dependent on the presence of a near-wall region, and that such a flow can exist by itself. The technique enables us to perform conceptual experiments to clarify what is essential to the logarithmic layer. For example, preliminary results show that the logarithmic layer cannot be created only by a non-uniform shear, and requires a spatial gradient of the scales of the fluctuations. Somewhat surprisingly, some simulations result in Kármán constants fairly different from κ=0.4, providing clues to what determines κ in real wall turbulence.

  10. Frontal bone fractures.

    PubMed

    Marinheiro, Bruno Henrique; de Medeiros, Eduardo Henrique Pantosso; Sverzut, Cássio Edvard; Trivellato, Alexandre Elias

    2014-11-01

    The aim of this retrospective study was to evaluate the epidemiology, treatment, and complications of frontal bone fractures associated, or not, with other facial fractures. This evaluation also sought to minimize the influence of the surgeon's skills and the preference for any rigid internal fixation system. The files from 3758 patients who attended the Oral and Maxillofacial Surgery Department of the School of Dentistry of Ribeirao Preto, University of Sao Paulo, from March 2004 to November 2011 and presented with facial trauma were scanned, and 52 files were chosen for the review. Eleven (21.15%) of these patients had pure fractures of the frontal bone, and trauma incidence was more prevalent in men (92.3%), whites (61.53%), and adults (50%). Despite the use of helmets at the moment of the trauma, motorcycle crashes were the most common etiological factor (32.69%). Fracture of the anterior wall of the frontal sinus with displacement was the main injury observed (54.9%), and the most common treatment was internal fixation with a plate and screws (45.09%). Postoperative complications were observed in 35.29% of the cases. The therapy applied was effective in handling this type of fracture, and the success rate was comparable to that reported in other published studies.

  11. Melt fracture revisited

    SciTech Connect

    Greenberg, J. M.

    2003-07-16

    In a previous paper the author and Demay advanced a model to explain the melt fracture instability observed when molten linear polymer melts are extruded in a capillary rheometer operating under the controlled condition that the inlet flow rate was held constant. The model postulated that the melts were a slightly compressible viscous fluid and allowed for slipping of the melt at the wall. The novel feature of that model was the use of an empirical switch law which governed the amount of wall slip. The model successfully accounted for the oscillatory behavior of the exit flow rate, typically referred to as the melt fracture instability, but did not simultaneously yield the fine scale spatial oscillations in the melt typically referred to as shark skin. In this note a new model is advanced which simultaneously explains the melt fracture instability and shark skin phenomena. The model postulates that the polymer is a slightly compressible linearly viscous fluid but assumes no slip boundary conditions at the capillary wall. In simple shear the shear stress {tau}and strain rate d are assumed to be related by d = F{tau} where F ranges between F{sub 2} and F{sub 1} > F{sub 2}. A strain rate dependent yield function is introduced and this function governs whether F evolves towards F{sub 2} or F{sub 1}. This model accounts for the empirical observation that at high shears polymers align and slide more easily than at low shears and explains both the melt fracture and shark skin phenomena.

  12. Hamate fractures.

    PubMed

    Sarabia Condés, J M; Ibañez Martínez, L; Sánchez Carrasco, M A; Carrillo Julia, F J; Salmerón Martínez, E L

    2015-01-01

    The purpose of this paper is to present our experience in the treatment of the fractures of the hamate and to make a review of the literature on this topic. We retrospectively reviewed 10 patients treated in our clinic between 2005-2012 suffering from fractures of the hamate. Six cases were fractures of the body and four were fractures of the hamate. Five cases were of associated injuries. Diagnostic delay ranged from 30 days to 2 years. Patient follow-up ranged from 1 to 10 years. Patient satisfaction was evaluated using the DASH questionnaire. Five patients with a fracture of the body underwent surgery, and one was treated conservatively. Two patients with fracture of the hook of the hamate were treated with immobilization, and two more patients had the fragment removed. The grip strength and the digital clip were reduced in 2 cases. Flexion and extension of the wrist was limited in 3 cases. The mobility of the fingers was normal in all the cases, except in one. The results obtained from the DASH questionnaire were normal in all the cases, except in one case of fracture of the hamate, and in two cases of fracture of the body. The surgical treatment should reduce the dislocation and stabilize the injuries with osteosynthesis. The fractures of the hamate are usually diagnosed late, and the most recommended treatment is removal of the fragment, although it cannot be deduced from this study. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  13. The Hot Orbit: Orbital Cellulitis

    PubMed Central

    Chaudhry, Imtiaz A.; Al-Rashed, Waleed; Arat, Yonca O.

    2012-01-01

    Orbital cellulitis is an uncommon condition previously associated with severe complications. If untreated, orbital cellulitis can be potentially sight and life threatening. It can affect both adults and children but has a greater tendency to occur in the pediatric age group. The infection most commonly originates from sinuses, eyelids or face, retained foreign bodies, or distant soources by hematogenous spread. It is characterized by eyelid edema, erythema, chemosis, proptosis, blurred vision, fever, headache, and double vision. A history of upper respiratory tract infection prior to the onset is very common especially in children. In the era prior to antibiotics, vision loss from orbital cellulitis was a dreaded complication. Currently, imaging studies for detection of orbital abcess, the use of antibiotics and early drainage have mitigated visual morbidity significantly. The purpose of this review is to describe current investigative strategies and management options in the treatment of orbital cellulitis, establish their effectiveness and possible complications due to late intervention. PMID:22346113

  14. Inflammation of the Orbit

    MedlinePlus

    ... Cavernous Sinus Thrombosis Inflammation of the Orbit Orbital Cellulitis Preseptal Cellulitis Tumors of the Orbit Any or all of ... Cavernous Sinus Thrombosis Inflammation of the Orbit Orbital Cellulitis Preseptal Cellulitis Tumors of the Orbit NOTE: This ...

  15. 'Sutureless' transconjunctival approach for infraorbital rim fractures.

    PubMed

    Nagaraj, Vaibhav; Ghosh, Abhishek; Nanjappa, Madan; Ramesh, Keerthi

    2015-03-01

    To analyze the ease and surgical outcome of using sutureless transconjunctival approach for repair of infra-orbital fractures. Prospective clinical case series. Totally 5 patients with infra-orbital rim or orbital floor fractures were selected and the fractures were accessed through a pre-septal transconjunctival incision. After reduction and fixation, the conjunctiva was just re-approximated and re-draped into position. Incidence of post-operative complications such as diplopia, lid retraction, eyelid dystopia, foreign body granuloma and poor conjunctival healing was assessed at intervals of 1 week, 15 days and a month post-operatively. No complications were observed in any of the 5 patients. Healing was satisfactory in all patients. The sutureless technique appears to be a time saving and technically simpler viable alternative to multilayered suturing in orbital trauma with minimal post-operative complications.

  16. How to simplify the CT diagnosis of Le Fort fractures.

    PubMed

    Rhea, James T; Novelline, Robert A

    2005-05-01

    The numerous components seen in the Le Fort fractures make classification difficult. Our objective is to simplify the task of classifying Le Fort fractures. Each of the Le Fort fractures has at least one unique component that is easily recognizable: I, the anterolateral margin of the nasal fossa; II, the inferior orbital rim; and III, the zygomatic arch. Classification of the Le Fort fractures is simplified by using these unique components to establish a tentative classification that is then confirmed.

  17. Orbital pseudotumor

    MedlinePlus

    ... Goodlick TA, Kay MD, Glaser JS, Tse DT, Chang WJ. Orbital disease and neuro-ophthalmology. In: Tasman ... 423. Review Date 8/20/2016 Updated by: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La ...

  18. Orbital Myiasis

    PubMed Central

    Khataminia, Gholamreza; Aghajanzadeh, Roja; Vazirianzadeh, Babak; Rahdar, Mahmoud

    2011-01-01

    Purpose To present a case of massive orbital myiasis. Case Report An 87-year-old debilitated woman suffering from left ocular pain of four days’ duration presented with a severely necrotized left orbit and several attached live larvae. The upper and lower eyelids and the eyeball were completely destroyed. She had history of eyelid surgery in the same eye due to a skin lesion, apparently some type of skin cancer, 15 years before. The larvae were identified as Chrysomya bezziana (Diptera: Calliphoridae) or old world screwworm fly. Conclusion Infestation of ocular and orbital tissues by fly larvae (ophthalmomyiasis) progresses rapidly and can completely destroy orbital tissues within days, especially in patients with poor general health. Treatment consists of removal of the larvae and surgical debridement. PMID:22454736

  19. Orbiter's Skeleton

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The structure of NASA's Mars Reconnaissance Orbiter spacecraft is constructed from composite panels of carbon layers over aluminum honeycomb, lightweight yet strong. This forms a basic structure or skeleton on which the instruments, electronics, propulsion and power systems can be mounted. The propellant tank is contained in the center of the orbiter's structure. This photo was taken at Lockheed Martin Space Systems, Denver, during construction of the spacecraft.

  20. Ankle fracture - aftercare

    MedlinePlus

    Malleolar fracture; Tri-malleolar; Bi-malleolar; Distal tibia fracture; Distal fibula fracture; Malleolus fracture ... Some ankle fractures may require surgery when: The ends of the bone are out of line with each other (displaced). The ...

  1. Treatment of traumatic infra orbital nerve paresthesia

    PubMed Central

    Lone, Parveen Akhter; Singh, R. K.; Pal, U. S.

    2012-01-01

    This study was done to find out the role of topiramate therapy in infraorbital nerve paresthesia after miniplate fixation in zygomatic complxex fractures. A total 2 cases of unilateral zygomatic complex fracture, 2-3 weeks old with infra orbital nerve paresthesia were slected. Open reduction and plating was done in frontozygomaticregion. Antiepileptic drug tab topiramate was given in therapeutic doses and dose was increased slowly until functional recovery was noticed. PMID:23833503

  2. Fracture line distribution of olecranon fractures.

    PubMed

    Lubberts, Bart; Mellema, Jos J; Janssen, Stein J; Ring, David

    2017-01-01

    The association between specific olecranon fracture characteristics (e.g., displacement, fragmentation, subluxation) and fracture line distribution might help surgeons predict intra-articular fracture location based on fracture characteristics that can be determined on radiographs. We hypothesized that fracture mapping techniques would reveal different fracture patterns for minimally displaced fractures, displaced fractures, and fracture-dislocations of the olecranon. A consecutive series of 78 patients with olecranon fractures were evaluated using initial radiographs and computed tomography scans and characterized according to the Mayo classification. Fracture lines were identified based on reduced three-dimensional computed tomography reconstructions and graphically superimposed onto a standard template to create two-dimensional fracture maps. The fracture maps were then converted into fracture heat maps. Based on fracture and heat maps, fracture line location and patterns were determined. Six (7.7%) patients had a non- or minimally displaced fracture, 22 (28%) a displaced fracture, and 50 (64%) a fracture-dislocation of the olecranon. There were 27 (54%) anterior and 23 (46%) posterior olecranon fracture-dislocations. Fracture lines of non- or minimally displaced fractures and posterior fracture-dislocations enter and exit the trochlear notch at the base of the coronoid, while fracture lines of displaced fractures and anterior fracture-dislocations were spread more broadly over the depths of the trochlear notch. Based on fracture characteristics depicted on radiographs, one can anticipate the amount of the olecranon involved (how close is the fracture line to the coronoid) and the orientation of the fracture line. Computer tomography could be reserved for when more specific knowledge of the fracture line might affect treatment. III.

  3. Wonderful Walls

    ERIC Educational Resources Information Center

    Greenman, Jim

    2006-01-01

    In this article, the author emphasizes the importance of "working" walls in children's programs. Children's programs need "working" walls (and ceilings and floors) which can be put to use for communication, display, storage, and activity space. The furnishings also work, or don't work, for the program in another sense: in aggregate, they serve as…

  4. A Case of Orbital Histoplasmosis.

    PubMed

    Krakauer, Mark; Prendes, Mark Armando; Wilkes, Byron; Lee, Hui Bae Harold; Fraig, Mostafa; Nunery, William R

    2016-01-01

    Histoplasma capsulatum var capsulatum is a dimorphic fungus endemic to the Ohio and Mississippi River Valleys of the United States. In this case report, a 33-year-old woman who presented with a right orbital mass causing progressive vision loss, diplopia, and facial swelling is described. Lateral orbitotomy with lateral orbital wall bone flap was performed for excisional biopsy of the lesion. The 1.5 × 1.8 × 2.3 cm cicatricial mass demonstrated a granulomatous lesion with necrosis and positive staining consistent with Histoplasma capsulatum var capsulatum infection. To the authors' knowledge, this is the first case of orbital histoplasmosis to be reported in the United States and the first case worldwide of orbital histoplasmosis due to Histoplasma capsulatum var capsulatum.

  5. Orbital Debris

    NASA Technical Reports Server (NTRS)

    Kessler, D. J. (Compiler); Su, S. Y. (Compiler)

    1985-01-01

    Earth orbital debris issues and recommended future activities are discussed. The workshop addressed the areas of environment definition, hazards to spacecraft, and space object management. It concluded that orbital debris is a potential problem for future space operations. However, before recommending any major efforts to control the environment, more data are required. The most significant required data are on the population of debris smaller than 4 cm in diameter. New damage criteria are also required. When these data are obtained, they can be combined with hypervelocity data to evaluate the hazards to future spacecraft. After these hazards are understood, then techniques to control the environment can be evaluated.

  6. Hip Fracture

    MedlinePlus

    ... make older people more likely to trip and fall — one of the most common causes of hip ... Taking steps to maintain bone density and avoid falls can help prevent hip fracture. Signs and symptoms ...

  7. Fracture Management

    MedlinePlus

    ... to hold the fracture in the correct position. • Fiberglass casting is lighter and stronger and the exterior ... with your physician if this occurs. • When a fiberglass cast is used in conjunction with a GORE- ...

  8. Laboratory Visualization Experiments of Temperature-induced Fractures Around a Borehole (Cryogenic Fracturing) in Shale and Analogue Rock Samples

    NASA Astrophysics Data System (ADS)

    Kneafsey, T. J.; Nakagawa, S.; Wu, Y. S.; Mukhopadhyay, S.

    2014-12-01

    In tight shales, hydraulic fracturing is the dominant method for improving reservoir permeability. However, injecting water-based liquids can induce formation damage and disposal problems, thus other techniques are being sought. One alternative to hydraulic fracturing is producing fractures thermally, using low-temperature fluids (cryogens). The primary consequence of thermal stimulation is that shrinkage fractures are produced around the borehole wall. Recently, cryogenic stimulation produced some promising results when the cryogen (typically liquid nitrogen and cold nitrogen gas) could be brought to reservoir depth. Numerical modeling also showed possible significant increases in gas production from a shale reservoir after cryogenic stimulation. However, geometry and the dynamic behavior of these thermally induced fractures under different stress regimes and rock anisotropy and heterogeneity is not yet well understood.Currently, we are conducting a series of laboratory thermal fracturing experiments on Mancos Shale and transparent glass blocks, by injecting liquid nitrogen under atmospheric pressure into room temperature blocks under various anisotropic stress states. The glass blocks allow clear optical visualization of fracture development and final fracturing patterns. For the shale blocks, X-ray CT is used to image both pre-existing and induced fractures. Also, the effect of borehole orientation with respect to the bedding planes and aligned preexisting fractures is examined. Our initial experiment on a uniaxially compressed glass block showed fracturing behavior which was distinctly different from conventional hydraulic fracturing. In addition to tensile fractures in the maximum principal stress directions, the thermal contraction by the cryogen induced (1) chaotic, spalling fractures around the borehole wall, and (2) a series of disk-shaped annular fractures perpendicular to the borehole. When applied to a horizontal borehole, the propagation plane of the

  9. Blowout Fracture in a 3-Year-Old

    PubMed Central

    Pluijmers, Britt I.; Koudstaal, Maarten J.; Paridaens, Dion; van der Wal, Karel G.H.

    2013-01-01

    A 3-year-old patient was referred to the oral and maxillofacial department with a fracture of the orbital floor. Due to the lack of clinical symptoms, a conservative approach was chosen. After 3 weeks, an enophthalmos developed. The orbital floor reconstruction was successfully performed through a transconjunctival approach. This case highlights the rarity of pure blowout fractures in young children. The specific presentation and diagnostics of orbital floor fractures in children and the related surgical planning and intervention are discussed. PMID:24436749

  10. Lisfranc fractures.

    PubMed

    Wright, Amanda; Gerhart, Ann E

    2009-01-01

    Injuries of the tarsometatarsal, or Lisfranc, joint are rarely seen. Lisfranc fractures and fracture dislocations are among the most frequently misdiagnosed foot injuries in the emergency department. A misdiagnosed injury may have severe consequences including chronic pain and loss of foot biomechanics. Evaluation of a foot injury should include a high level of suspicion of a Lisfranc injury, and a thorough work-up is needed for correct diagnosis.

  11. Colles' fracture.

    PubMed

    Altizer, Linda L

    2008-01-01

    Many people "slip and fall", especially in the icy areas of the winter season. To prevent an injury to the head, most people put their hand out to hit the ground first, so the wrist usually gets injured. The most frequent injury from this type of "intervention" is a fracture to the distal radius and/or ulna, which is frequently called a "Colles' fracture."

  12. Prospecting from Orbit

    NASA Image and Video Library

    2017-09-04

    The combination of morphological and topographic information from stereo images from NASA's Mars Reconnaissance Orbiter, as well as compositional data from near-infrared spectroscopy has been proven to be a powerful tool for understanding the geology of Mars. Beginning with the OMEGA instrument on the European Space Agency's Mars Express orbiter in 2003, the surface of Mars has been examined at near-infrared wavelengths by imaging spectrometers that are capable of detecting specific minerals and mapping their spatial extent. The CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) instrument on our orbiter is a visible/near-infrared imaging spectrometer, and the HiRISE camera works together with it to document the appearance of mineral deposits detected by this orbital prospecting. Mawrth Vallis is one of the regions on Mars that has attracted much attention because of the nature and diversity of the minerals identified by these spectrometers. It is a large, ancient outflow channel on the margin of the Southern highlands and Northern lowlands. Both the OMEGA and CRISM instruments have detected clay minerals here that must have been deposited in a water-rich environment, probably more than 4 billion years ago. For this reason, Mawrth Vallis is one of the two candidate landing sites for the future Mars Express Rover Mission planned by the European Space Agency. This image was targeted on a location where the CRISM instrument detected a specific mineral called alunite, KAl3(SO4)2(OH)6. Alunite is a hydrated aluminum potassium sulfate, a mineral that is notable because it must have been deposited in a wet acidic environment, rich in sulfuric acid. Our image shows that the deposit is bright and colorful, and extensively fractured. The width of the cutout is 1.2 kilometers. https://photojournal.jpl.nasa.gov/catalog/PIA21936

  13. Late extrusion of alloplastic orbital floor implants.

    PubMed

    Brown, A E; Banks, P

    1993-06-01

    Complications following the use of alloplastic orbital floor implants are well documented but it is not widely recognised that these can occur many years after initial treatment. Three patients who presented with late extrusion of an implant through the facial skin are reported. This complication occurred 10, 16 and 17 years respectively after treatment of the orbital floor fracture. The tissue reaction to silicone rubber and Teflon inplants is reviewed and the possible cause for this late complication is discussed.

  14. Nuclear orbiting

    SciTech Connect

    Shapira, D.

    1988-01-01

    Nuclear orbiting following collisions between sd and p shell nuclei is discussed. The dependence of this process on the real and imaginary parts of the nucleus-nucleus potential is discussed, as well as the evolution of the dinucleus toward a fully equilibrated fused system. 26 refs., 15 figs.

  15. Use of Orbital Conformer to Improve Speech in Patients with Confluent Maxillectomy and Orbital Defects

    PubMed Central

    Colebeck, Amanda C.; Kase, Michael T.; Nichols, Cindy B.; Golden, Marjorie; Huryn, Joseph M.

    2016-01-01

    The basic objective in prosthetic restoration of confluent maxillary and orbital defects is to achieve a comfortable, cosmetically acceptable prosthesis that restores speech, deglutition, and mastication. It is a challenging task complicated by the size and shape of the defects. The maxillary obturator prosthesis often satisfies the objective of adequate deglutition; however, orbital defects that are not obturated in the medial septal or posterior walls allow air to escape, negatively impacting phonation. This article describes a technique to achieve favorable prosthetic rehabilitation in a patient with a maxillectomy and ipsilateral orbital exenteration. The prosthetic components include maxillary obturator, orbital conformer, and orbital prosthesis connected using rigid magnetic attachments. PMID:25953143

  16. Gullies in Crater Wall

    NASA Technical Reports Server (NTRS)

    2004-01-01

    6 April 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies in the wall of a large impact crater in Newton Basin near 41.9oS, 158.1oW. Such gullies may have formed by downslope movement of wet debris--i.e., water. Unfortunately, because the responsible fluid (if there was one) is no longer present today, only the geomorphology of the channels and debris aprons can be used to deduce that water might have been involved. The image covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.

  17. Gullies in Crater Wall

    NASA Technical Reports Server (NTRS)

    2004-01-01

    6 April 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies in the wall of a large impact crater in Newton Basin near 41.9oS, 158.1oW. Such gullies may have formed by downslope movement of wet debris--i.e., water. Unfortunately, because the responsible fluid (if there was one) is no longer present today, only the geomorphology of the channels and debris aprons can be used to deduce that water might have been involved. The image covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.

  18. Wall Turbulence.

    ERIC Educational Resources Information Center

    Hanratty, Thomas J.

    1980-01-01

    This paper gives an account of research on the structure of turbulence close to a solid boundary. Included is a method to study the flow close to the wall of a pipe without interferring with it. (Author/JN)

  19. Vibrational modes of hydraulic fractures: Inference of fracture geometry from resonant frequencies and attenuation

    NASA Astrophysics Data System (ADS)

    Lipovsky, Bradley P.; Dunham, Eric M.

    2015-02-01

    Oscillatory seismic signals arising from resonant vibrations of hydraulic fractures are observed in many geologic systems, including volcanoes, glaciers and ice sheets, and hydrocarbon and geothermal reservoirs. To better quantify the physical dimensions of fluid-filled cracks and properties of the fluids within them, we study wave motion along a thin hydraulic fracture waveguide. We present a linearized analysis, valid at wavelengths greater than the fracture aperture, that accounts for quasi-static elastic deformation of the fracture walls, as well as fluid viscosity, inertia, and compressibility. In the long-wavelength limit, anomalously dispersed guided waves known as crack or Krauklis waves propagate with restoring force from fracture wall elasticity. At shorter wavelengths, the waves become sound waves within the fluid channel. Wave attenuation in our model is due to fluid viscosity, rather than seismic radiation from crack tips or fracture wall roughness. We characterize viscous damping at both low frequencies, where the flow is always fully developed, and at high frequencies, where the flow has a nearly constant velocity profile away from viscous boundary layers near the fracture walls. Most observable seismic signals from resonating fractures likely arise in the boundary layer crack wave limit, where fluid-solid coupling is pronounced and attenuation is minimal. We present a method to estimate the aperture and length of a resonating hydraulic fracture using both the seismically observed quality factor and characteristic frequency. Finally, we develop scaling relations between seismic moment and characteristic frequency that might be useful when interpreting the statistics of hydraulic fracture events.

  20. General view of he forward wall of the mid deck ...

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

    General view of he forward wall of the mid deck of the Orbiter Discovery. In this view a majority of wall panels have been removed to reveal the avionics bays in the interstitial space between the mid deck forward wall and the forward bulkhead of the pressurized crew compartment. This photograph was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  1. Pediatric Thighbone (Femur) Fracture

    MedlinePlus

    ... fractures in infants under 1 year old is child abuse. Child abuse is also a leading cause of thighbone fracture ... contact sports • Being in a motor vehicle accident • Child abuse Types of Femur Fractures (Classification) Femur fractures vary ...

  2. Hydraulic fracturing-1

    SciTech Connect

    Not Available

    1990-01-01

    This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

  3. Fracture types (1) (image)

    MedlinePlus

    ... fracture which goes at an angle to the axis Comminuted - a fracture of many relatively small fragments Spiral - a fracture which runs around the axis of the bone Compound - a fracture (also called ...

  4. Galeazzi fracture.

    PubMed

    Atesok, Kivanc I; Jupiter, Jesse B; Weiss, Arnold-Peter C

    2011-10-01

    Galeazzi fracture is a fracture of the radial diaphysis with disruption at the distal radioulnar joint (DRUJ). Typically, the mechanism of injury is forceful axial loading and torsion of the forearm. Diagnosis is established on radiographic evaluation. Underdiagnosis is common because disruption of the ligamentous restraints of the DRUJ may be overlooked. Nonsurgical management with anatomic reduction and immobilization in a long-arm cast has been successful in children. In adults, nonsurgical treatment typically fails because of deforming forces acting on the distal radius and DRUJ. Open reduction and internal fixation is the preferred surgical option. Anatomic reduction and rigid fixation should be followed by intraoperative assessment of the DRUJ. Further intraoperative interventions are based on the reducibility and postreduction stability of the DRUJ. Misdiagnosis or inadequate management of Galeazzi fracture may result in disabling complications, such as DRUJ instability, malunion, limited forearm range of motion, chronic wrist pain, and osteoarthritis.

  5. Calcaneus fractures: facts, controversies and recent developments.

    PubMed

    Rammelt, Stefan; Zwipp, Hans

    2004-05-01

    The management of calcaneus fractures and their associated soft tissue injuries are challenging tasks for the surgeon. Open reduction and stable internal fixation with a lateral plate and without joint transfixation has been established as a standard therapy for displaced intra-articular fractures with good to excellent results in two-thirds to three-quarters of cases in larger clinical series. Bone grafting appears not useful in the vast majority of cases. Anatomical reduction of joint congruity and the overall shape of the calcaneus are important prognostic factors. The quality of joint reduction should be reliably proven intra-operatively either with Brodén views, high-resolution fluoroscopy or open subtalar arthroscopy. Treatment results are adversely affected by open fractures, delayed reduction after more than 14 days and individual risk factors such as high body mass index and smoking. The extended lateral approach respects the neurovascular supply to the heel and allows a good exposure of the fractured lateral wall, and the subtalar and calcaneocuboid joints in most fractures. In selected fracture patterns percutaneous screw fixation, possibly with arthroscopic control, is a good alternative. Open fractures, compartment syndrome and fractures with severe soft tissue compromise are treated as emergency cases. Early, stable soft tissue coverage appears promising in treating complex open fractures. The benefits of newly developed plate designs and subtalar arthrolysis at the time of hardware removal remains to be proven in further studies. Calcaneal malunions after conservative therapy of displaced fractures are disabling conditions that can be treated successfully with a staged protocol according to the type of deformity. Treatment options include lateral wall decompression, subtalar in situ, or corrective, arthrodesis and calcaneal osteotomy along the former fracture line.

  6. Wall Shear Stress, Wall Pressure and Near Wall Velocity Field Relationships in a Whirling Annular Seal

    NASA Technical Reports Server (NTRS)

    Morrison, Gerald L.; Winslow, Robert B.; Thames, H. Davis, III

    1996-01-01

    The mean and phase averaged pressure and wall shear stress distributions were measured on the stator wall of a 50% eccentric annular seal which was whirling in a circular orbit at the same speed as the shaft rotation. The shear stresses were measured using flush mounted hot-film probes. Four different operating conditions were considered consisting of Reynolds numbers of 12,000 and 24,000 and Taylor numbers of 3,300 and 6,600. At each of the operating conditions the axial distribution (from Z/L = -0.2 to 1.2) of the mean pressure, shear stress magnitude, and shear stress direction on the stator wall were measured. Also measured were the phase averaged pressure and shear stress. These data were combined to calculate the force distributions along the seal length. Integration of the force distributions result in the net forces and moments generated by the pressure and shear stresses. The flow field inside the seal operating at a Reynolds number of 24,000 and a Taylor number of 6,600 has been measured using a 3-D laser Doppler anemometer system. Phase averaged wall pressure and wall shear stress are presented along with phase averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure and wall shear stress are very complex and do not follow simple bulk flow predictions.

  7. Wall Shear Stress, Wall Pressure and Near Wall Velocity Field Relationships in a Whirling Annular Seal

    NASA Technical Reports Server (NTRS)

    Morrison, Gerald L.; Winslow, Robert B.; Thames, H. Davis, III

    1996-01-01

    The mean and phase averaged pressure and wall shear stress distributions were measured on the stator wall of a 50% eccentric annular seal which was whirling in a circular orbit at the same speed as the shaft rotation. The shear stresses were measured using flush mounted hot-film probes. Four different operating conditions were considered consisting of Reynolds numbers of 12,000 and 24,000 and Taylor numbers of 3,300 and 6,600. At each of the operating conditions the axial distribution (from Z/L = -0.2 to 1.2) of the mean pressure, shear stress magnitude, and shear stress direction on the stator wall were measured. Also measured were the phase averaged pressure and shear stress. These data were combined to calculate the force distributions along the seal length. Integration of the force distributions result in the net forces and moments generated by the pressure and shear stresses. The flow field inside the seal operating at a Reynolds number of 24,000 and a Taylor number of 6,600 has been measured using a 3-D laser Doppler anemometer system. Phase averaged wall pressure and wall shear stress are presented along with phase averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure and wall shear stress are very complex and do not follow simple bulk flow predictions.

  8. A Novel Method of Orbital Floor Reconstruction Using Virtual Planning, 3-Dimensional Printing, and Autologous Bone.

    PubMed

    Vehmeijer, Maarten; van Eijnatten, Maureen; Liberton, Niels; Wolff, Jan

    2016-08-01

    Fractures of the orbital floor are often a result of traffic accidents or interpersonal violence. To date, numerous materials and methods have been used to reconstruct the orbital floor. However, simple and cost-effective 3-dimensional (3D) printing technologies for the treatment of orbital floor fractures are still sought. This study describes a simple, precise, cost-effective method of treating orbital fractures using 3D printing technologies in combination with autologous bone. Enophthalmos and diplopia developed in a 64-year-old female patient with an orbital floor fracture. A virtual 3D model of the fracture site was generated from computed tomography images of the patient. The fracture was virtually closed using spline interpolation. Furthermore, a virtual individualized mold of the defect site was created, which was manufactured using an inkjet printer. The tangible mold was subsequently used during surgery to sculpture an individualized autologous orbital floor implant. Virtual reconstruction of the orbital floor and the resulting mold enhanced the overall accuracy and efficiency of the surgical procedure. The sculptured autologous orbital floor implant showed an excellent fit in vivo. The combination of virtual planning and 3D printing offers an accurate and cost-effective treatment method for orbital floor fractures.

  9. Eye and orbit ultrasound

    MedlinePlus

    Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... ophthalmology department of a hospital or clinic. Your eye is numbed with medicine (anesthetic drops). The ultrasound ...

  10. Relative Dating Via Fractures

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    This VIS image of the eastern part of the Tharsis region illustrates how fractures can be used in relative dating of a surface. The fractured materials on the right side of the image are embayed by younger volcanic flows originating to the west of the image. Note how the younger flows cover the ends of the fractures, and are not at all fractured themselves.

    Image information: VIS instrument. Latitude 43.2, Longitude 269.4 East (90.6 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  11. Relative Dating Via Fractures

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    This VIS image of the eastern part of the Tharsis region illustrates how fractures can be used in relative dating of a surface. The fractured materials on the right side of the image are embayed by younger volcanic flows originating to the west of the image. Note how the younger flows cover the ends of the fractures, and are not at all fractured themselves.

    Image information: VIS instrument. Latitude 43.2, Longitude 269.4 East (90.6 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  12. Cemented Fractures in Mountain Inside Gale Crater on Mars

    NASA Image and Video Library

    2011-07-22

    One type of feature of scientific interest on the mountain inside Gale crater is exposure of cemented fractures, evidence that groundwater once reached to at least that height of the mountain. This image is from NASA Mars Reconnaissance Orbiter.

  13. Predictability in orbital reconstruction: A human cadaver study. Part II: Navigation-assisted orbital reconstruction.

    PubMed

    Dubois, Leander; Schreurs, Ruud; Jansen, Jesper; Maal, Thomas J J; Essig, Harald; Gooris, Peter J J; Becking, Alfred G

    2015-12-01

    Preformed orbital reconstruction plates are useful for treating orbital defects. However, intraoperative errors can lead to misplaced implants and poor outcomes. Navigation-assisted surgery may help optimize orbital reconstruction. We aimed to explore whether navigation-assisted surgery is more predictable than traditional orbital reconstruction for optimal implant placement. Pre-injury computed tomography scans were obtained for 10 cadaver heads (20 orbits). Complex orbital fractures (Class III-IV) were created in all orbits, which were reconstructed using a transconjunctival approach with and without navigation. The best possible fit of the stereolithographic file of a preformed orbital mesh plate was used as the optimal position for reconstruction. The accuracy of the implant positions was evaluated using iPlan software. The consistency of orbital reconstruction was lower in the traditional reconstructions than in the navigation group in the parameters of translation and rotation. Implant position also differed significantly in the parameters of translation (p = 0.002) and rotation (pitch: p = 0.77; yaw: p < 0.001; roll: p = 0.001). Compared with traditional orbital reconstruction, navigation-assisted reconstruction provides more predictable anatomical reconstruction of complex orbital defects and significantly improves orbital implant position.

  14. The Orbital Workshop Sleep Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This wide-angle view is of the Orbital Workshop (OWS) sleep compartment, located in the lower level of the OWS. Each crewman was assigned a small space for sleeping and zipped themselves into sleeping bags stretched against the wall. Because of the absence of gravity, sleeping comfort was achieved in any position relative to the spacecraft; body support was not necessary. Sleeping could be accommodated quite comfortably in a bag that held the body at a given place in Skylab.

  15. Lithiation induced corrosive fracture in defective carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Huang, Xu; Yang, Hui; Liang, Wentao; Raju, Muralikrishna; Terrones, Mauricio; Crespi, Vincent H.; van Duin, Adri C. T.; Zhang, Sulin

    2013-10-01

    We perform molecular dynamics simulations to elucidate lithiation induced fracture mechanisms of defective single-walled carbon nanotubes (SWCNTs). Our simulations reveal that variations of defect size and lithium concentration set two distinct fracture modes of the SWCNTs upon uniaxial stretch: abrupt and retarded fracture. Abrupt fracture either involves spontaneous lithium weakening of the propagating crack tip or is absent of lithium participation, while retarded fracture features a "wait-and-go" crack extension process in which the crack tip periodically arrests and waits to be weakened by diffusing lithium before extension resumes. Our study sheds light on the rational design of high-performance CNT-based electrodes.

  16. Orbit analysis

    SciTech Connect

    Michelotti, L.

    1995-01-01

    The past fifteen years have witnessed a remarkable development of methods for analyzing single particle orbit dynamics in accelerators. Unlike their more classic counterparts, which act upon differential equations, these methods proceed by manipulating Poincare maps directly. This attribute makes them well matched for studying accelerators whose physics is most naturally modelled in terms of maps, an observation that has been championed most vigorously by Forest. In the following sections the author sketchs a little background, explains some of the physics underlying these techniques, and discusses the best computing strategy for implementing them in conjunction with modeling accelerators.

  17. Microsurgical Anatomy of the Orbit: The Rule of Seven

    PubMed Central

    Martins, Carolina; Costa e Silva, Isabel Eugênia; Campero, Alvaro; Yasuda, Alexandre; Aguiar, Luiz Roberto; Tatagiba, Marcos; Rhoton, Albert

    2011-01-01

    The orbits are paired structures, located on the anterior part of the face. Morphologically, each orbit is a four sided pyramid with a posterior apex and anterior base. In the orbit, all openings are arranged around the base, apex or between the orbital walls. An anatomical characteristic of the orbit is that structures are arranged in groups of seven: there are seven bones, seven intraorbital muscles and seven nerves in the orbit. Tumors confined within the periorbita in the anterior two thirds of the orbit can often be approached extracranially, but those located in the apical area, and especially those on the medial side of the optic nerve, often require a transcranial approach. Thus, knowledge of orbital osteology is paramount in adequately choosing and performing an orbital approach. Understanding the critical topographical elements in this area helps to classify an orbital lesion and provides for a solid basis in choosing the most adequate intraorbital route for its treatment. PMID:22567293

  18. 'Stucco' Walls

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)

  19. 'Stucco' Walls

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)

  20. Condylar fractures.

    PubMed

    Sawhney, Raja; Brown, Ryan; Ducic, Yadranko

    2013-10-01

    The purpose of this article is to review the basic indications for different treatments of condylar and subcondylar fractures. It also reviews the steps of different surgical approaches to access the surgical area and explains the pros and cons of each procedure.

  1. Rib Fractures

    MedlinePlus

    ... Brain Damage in Boxers (News) Which High School Sport Has the Most Concussions? Additional Content Medical News Rib Fractures By Thomas ... often... More News News HealthDay Which High School Sport Has the Most Concussions? WEDNESDAY, March 15, 2017 (HealthDay News) -- Female soccer ...

  2. Patterns of fracture and tidal stresses on Europa

    NASA Technical Reports Server (NTRS)

    Helfenstein, P.; Parmentier, E. M.

    1983-01-01

    A comparison of dark band, triple band, and cuspate ridge orientations with the fracture patterns predicted for tidal distortion due to orbital recession and eccentricity is undertaken, to test the hypothesized identification of Europa's lineaments as tidal distortion and planetary volume change fractures. Short, reticule dark bands near the anti-Jove point could be tension cracks caused by orbital eccentricity. Long, arcuate dark bands and triple bands peripheral to the anti-Jove point may be strike-slip faults due to orbital recession. The orientation and distribution of cuspate ridges, if they are compressional, suggests their formation in response to a combination of orbital recession and planetary volume decrease. If surface fracturing is due to tidal deformation, important constraints are exerted by it on Europa's orbital evolution.

  3. Patterns of fracture and tidal stresses on Europa

    NASA Technical Reports Server (NTRS)

    Helfenstein, P.; Parmentier, E. M.

    1983-01-01

    A comparison of dark band, triple band, and cuspate ridge orientations with the fracture patterns predicted for tidal distortion due to orbital recession and eccentricity is undertaken, to test the hypothesized identification of Europa's lineaments as tidal distortion and planetary volume change fractures. Short, reticule dark bands near the anti-Jove point could be tension cracks caused by orbital eccentricity. Long, arcuate dark bands and triple bands peripheral to the anti-Jove point may be strike-slip faults due to orbital recession. The orientation and distribution of cuspate ridges, if they are compressional, suggests their formation in response to a combination of orbital recession and planetary volume decrease. If surface fracturing is due to tidal deformation, important constraints are exerted by it on Europa's orbital evolution.

  4. Gullies in Terraced Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-375, 29 May 2003

    Gullies--possibly formed by a liquid such as water in the recent martian past--formed at two different levels in the walls of a meteor impact crater near 36.2oS, 185.5oW. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies in the upper crater wall (top of the image) and emergent from the slope of a lower terrace (bottom of the image). Sunlight illuminates the scene from the upper left.

  5. Gullies in Terraced Crater Wall

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-375, 29 May 2003

    Gullies--possibly formed by a liquid such as water in the recent martian past--formed at two different levels in the walls of a meteor impact crater near 36.2oS, 185.5oW. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies in the upper crater wall (top of the image) and emergent from the slope of a lower terrace (bottom of the image). Sunlight illuminates the scene from the upper left.

  6. Frontal Sinus Fractures: Current Concepts

    PubMed Central

    Strong, E. Bradley

    2009-01-01

    Frontal sinus injuries may range from isolated anterior table fractures resulting in a simple aesthetic deformity to complex fractures involving the frontal recess, orbits, skull base, and intracranial contents. The risk of long-term morbidity can be significant. Optimal treatment strategies for the management of frontal sinus fractures remain controversial. However, it is critical to have a thorough understanding of frontal sinus anatomy as well as the current treatment strategies used to manage these injuries. A thorough physical exam and thin-cut, multiplanar (axial, coronal, and sagittal) computed tomography scan should be performed in all patients suspected of having a frontal sinus fracture. The most appropriate treatment strategy can be determined by assessing five anatomic parameters including the: frontal recess, anterior table integrity, posterior table integrity, dural integrity, and presence of a cerebrospinal fluid leak. A well thought out management strategy and meticulous surgical techniques are critical to success. The primary surgical goal is to provide a safe sinus while minimizing patient morbidity. This article offers an anatomically based treatment algorithm for the management of frontal sinus fractures and highlights the key steps to surgical repair. PMID:22110810

  7. Wall Art

    ERIC Educational Resources Information Center

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  8. Wall Art

    ERIC Educational Resources Information Center

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  9. Wall Covering

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The attractive wall covering shown below is one of 132 styles in the Mirror Magic II line offered by The General Tire & Rubber Company, Akron, Ohio. The material is metallized plastic fabric, a spinoff from space programs. Wall coverings are one of many consumer applications of aluminized plastic film technology developed for NASA by a firm later bought by King-Seeley Thermos Company, Winchester, Massachusetts, which now produces the material. The original NASA use was in the Echo 1 passive communications satellite, a "space baloon" made of aluminized mylar; the high reflectivity of the metallized coating enabled relay of communications signals from one Earth station to another by "bouncing" them off the satellite. The reflectivity feature also made the material an extremely efficient insulator and it was subsequently widely used in the Apollo program for such purposes as temperature control of spacecraft components and insulation of tanks for fuels that must be maintained at very low temperatures. I Used as a wall covering, the aluminized material offers extra insulation, reflects light and I resists cracking. In addition to General Tire, King-Seeley also supplies wall covering material to Columbus Coated Fabrics Division of Borden, Incorporated, Columbus, Ohio, among others.

  10. Orbital dissection defatting technique for Graves disease.

    PubMed

    Hecht, S D; Guibor, P; Wolfley, D; Wiggs, E O

    1984-04-01

    Five patients with Graves disease and bilateral proptosis were treated with different incisional approaches. They all underwent orbital decompression by removal of the anterior medial orbital walls, the anterior ethmoidal sinuses, the orbital floors, and multiple incisions of the orbital periosteums . The defatting technique, which consists of applying manual anterior orbital pressure with alternate removing of small lobules of fat, was added when it was intraoperatively decided by Hertel exophthalmometer measurement that more decompression was needed. It is estimated that one-third more reduction in proptosis resulted. An average total decrease in proptosis of 9 mm per orbit occurred. Both visual accuities and visual fields returned to normal. The only important complication was the development of hypertropia in down gaze in one patient. A potential value of this technique is its use with orbital floor decompression alone. It may be possible to avoid removing the medial and lateral walls of the orbit, thereby decreasing complications. Defatting may also be a valuable addition in those rare cases where all decompression techniques available are needed to affect an adequate decompression.

  11. Predictability in orbital reconstruction: A human cadaver study. Part I: Endoscopic-assisted orbital reconstruction.

    PubMed

    Dubois, Leander; Jansen, Jesper; Schreurs, Ruud; Saeed, Perooz; Beenen, Ludo; Maal, Thomas J J; Gooris, Peter J J; Becking, Alfred G

    2015-12-01

    In the treatment of orbital defects, surgeon errors may lead to incorrect positioning of orbital implants and, consequently, poor clinical outcomes. Endoscopy can provide additional visualization of the orbit through the transantral approach. We aimed to evaluate whether endoscopic guidance during orbital reconstruction facilitates optimal implant placement and can serve as a convenient alternative for navigation and intra-operative imaging. Ten human cadaveric heads were subjected to thin-slice computed tomography (CT). Complex orbital fractures (Class III/IV) were created in all eligible orbits (n = 19), which were then reconstructed using the conventional transconjunctival approach with or without endoscopic guidance. The ideal implant location was digitally determined using pre-operative CT images, and the accuracy of implant placement was evaluated by comparing the planned implant location with the postoperative location. There were no statistically significant differences (p > 0.05) in the degree of implant dislocation (translation and rotation) between the transconjunctival orbital reconstruction and the endoscopic-assisted orbital reconstruction groups. Endoscopic-assisted orbital reconstruction may facilitate the visualization of orbital defects and is particularly useful for training purposes; however, it offers no additional benefits in terms of accurate implant positioning during the anatomical reconstruction of complex orbital defects.

  12. CONTAMINANT TRANSPORT IN PARALLEL FRACTURED MEDIA: SUDICKY AND FRIND REVISITED

    EPA Science Inventory

    This paper is concerned with a modified, nondimensional form of the parallel fracture, contaminant transport model of Sudicky and Frind (1982). The modifications include the boundary condition at the fracture wall, expressed by a parameter, and the power-law relationship between...

  13. CONTAMINANT TRANSPORT IN PARALLEL FRACTURED MEDIA: SUDICKY AND FRIND REVISITED

    EPA Science Inventory

    This paper is concerned with a modified, nondimensional form of the parallel fracture, contaminant transport model of Sudicky and Frind (1982). The modifications include the boundary condition at the fracture wall, expressed by a parameter , and the power-law relationship betwe...

  14. CONTAMINANT TRANSPORT IN PARALLEL FRACTURED MEDIA: SUDICKY AND FRIND REVISITED

    EPA Science Inventory

    This paper is concerned with a modified, nondimensional form of the parallel fracture, contaminant transport model of Sudicky and Frind (1982). The modifications include the boundary condition at the fracture wall, expressed by a parameter , and the power-law relationship betwe...

  15. CONTAMINANT TRANSPORT IN PARALLEL FRACTURED MEDIA: SUDICKY AND FRIND REVISITED

    EPA Science Inventory

    This paper is concerned with a modified, nondimensional form of the parallel fracture, contaminant transport model of Sudicky and Frind (1982). The modifications include the boundary condition at the fracture wall, expressed by a parameter, and the power-law relationship between...

  16. Pearls of Orbital Trauma Management

    PubMed Central

    Roth, Forrest S.; Koshy, John C.; Goldberg, Jonathan S.; Soparkar, Charles N.S.

    2010-01-01

    Orbital fractures account for a significant portion of traumatic facial injuries. Although plastic surgery literature is helpful, additional pearls and insights are provided in this article from the experience of an oculoplastic surgeon. The fundamentals remain the same, but the perceptions differ and provide a healthy perspective on a long-standing issue. The most important thing to remember is that the optimal management plan is often variable, and the proper choice regarding which plan to choose rests upon the clinical scenario and the surgeon having an honest perception of his or her level of expertise and comfort level. PMID:22550464

  17. Orbital Winch

    NASA Technical Reports Server (NTRS)

    Hoyt, Robert (Inventor); Slostad, Jeffrey T. (Inventor); Frank, Scott (Inventor); Barnes, Ian M. (Inventor)

    2016-01-01

    Orbital winch having: lower and upper frames; spool having upper and lower flanges with lower flange attached to lower frame; axial tether guide mounted to upper frame; secondary slewing ring coaxial with spool and rotatably mounted to upper frame, wherein secondary slewing ring's outer surface has gearing; upper tether guide mounted to inner surface of secondary slewing ring; linear translation means having upper end mounted to upper frame and lower end mounted on lower frame; primary slewing ring rotatably mounted within linear translation means allowing translation axially between flanges, wherein primary slewing ring's outer surface has gearing; lower tether guide mounted on primary slewing ring's inner surface; pinion rod having upper end mounted to upper frame and lower end mounted to lower frame, wherein pinion rod's teeth engage primary and secondary slewing rings' outer surface teeth; and tether passing through axial, upper, and lower tether guides and winding around spool.

  18. Orbital liposarcoma.

    PubMed

    Borbolla-Pertierra, A M; Morales-Baños, D R; Martínez-Nava, L R; Garrido-Sánchez, G A; López-Hernández, C M; Velasco-Ramos, P

    2017-02-01

    The case is presented of a 46-year-old male with right eye proptosis and conjunctival hyperaemia, of 18 months onset. A well-defined intraconal mass was found in the computed tomography. In magnetic resonance this was hypo-intense on T1, enhanced with gadolinium and hyperintense on T2. Excisional biopsy was performed, which was reported as a well-differentiated liposarcoma in the histopathology study. Liposarcoma is a malignant adipose tissue tumour. It is very rare in the orbit, with 5 histological types, the most common being myxoid. The treatment of choice is wide surgical excision and may be accompanied with radiotherapy. As it is an infiltrative tumour, It has a high rate of recurrence. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. Lunar ring dikes from orbiter I.

    PubMed

    O'keefe, J A; Lowman, P D; Cameron, W S

    1967-01-06

    Orbiter photographs of the wall of a large circular formation on the moon show that the wall is a convex body resembling a flow of viscous lava. The slopes are less than the angle of repose of dry rock; hence an explanation in terms of mass wastage is hard to support. The viscosity is approximately 10(13) centimeter-gram- second units, indicating an acid lava.

  20. Simple Repair of a Blow-Out Fracture by the Modified Caldwell-Luc Approach.

    PubMed

    Park, Min Woo; Kim, Soung Min; Amponsah, Emmanuel Kofi; Lee, Suk Keun

    2015-06-01

    Here we report a patient with a blow-out fracture of the orbital floor that was treated by an intraoral transmaxillary approach. This 38-year-old man suffered a sudden blow to the periorbital area, which caused prolapse of the orbital contents into the maxillary sinus. The modified Caldwell-Luc approach was used to repair the orbital blow-out fracture and the maxillary sinus during was packed with Frazin gauze for 7 days to prevent recurrence of the prolapse. This was an easy and minimally invasive technique for the management of a blow-out fracture of the orbital floor.

  1. Facial Fractures

    PubMed Central

    White, Lawrence M.; Marotta, Thomas R.; McLennan, Michael K.; Kassel, Edward E.

    1992-01-01

    Appropriate clinical radiographic investigation, together with an understanding of the normal radiographic anatomy of the facial skeleton, allows for precise delineation of facial fracutres and associated soft tissue injuries encountered in clinical practice. A combination of multiple plain radiographic views and coronal and axial computed tomographic images allow for optimal delineation of fracture patterns. This information is beneficial in the clinical and surgical management patients with facial injuries

  2. Wall Turbulence

    DTIC Science & Technology

    1992-04-01

    Doppler velocimeter, computer experiments, and pulsed-laser velocimetry. External influences to be studied are imposed flow oscillations , wavy walls...imposed flow oscillations Studies of the effect of imposed small amplitude flow oscillations have shown no effect on the time mean flow. Work was...undertaken to see if imposed large amplitude oscillations can affect drag. The system used was water flow through a two inch pipe. The flow oscillations

  3. Hydraulic conductivity of rock fractures

    SciTech Connect

    Zimmerman, R.W.; Bodvarsson, G.S.

    1994-10-01

    Yucca Mountain, Nevada contains numerous geological units that are highly fractured. A clear understanding of the hydraulic conductivity of fractures has been identified as an important scientific problem that must be addressed during the site characterization process. The problem of the flow of a single-phase fluid through a rough-walled rock fracture is discussed within the context of rigorous fluid mechanics. The derivation of the cubic law is given as the solution to the Navier-Stokes equations for flow between smooth, parallel plates, the only fracture geometry that is amenable to exact treatment. The various geometric and kinetic conditions that are necessary in order for the Navier-Stokes equations to be replaced by the more tractable lubrication or Hele-Shaw equations are studied and quantified. Various analytical and numerical results are reviewed pertaining to the problem of relating the effective hydraulic aperture to the statistics of the aperture distribution. These studies all lead to the conclusion that the effective hydraulic aperture is always less than the mean aperture, by a factor that depends on the ratio of the mean value of the aperture to its standard deviation. The tortuosity effect caused by regions where the rock walls are in contact with each other is studied using the Hele-Shaw equations, leading to a simple correction factor that depends on the area fraction occupied by the contact regions. Finally, the predicted hydraulic apertures are compared to measured values for eight data sets from the literature for which aperture and conductivity data were available on the same fracture. It is found that reasonably accurate predictions of hydraulic conductivity can be made based solely on the first two moments of the aperture distribution function, and the proportion of contact area. 68 refs.

  4. Posttraumatic Intracranial Tuberculous Subdural Empyema in a Patient with Skull Fracture

    PubMed Central

    Kim, Jiha; Kim, Choonghyo; Ryu, Young-Joon

    2016-01-01

    Intracranial tuberculous subdural empyema (ITSE) is extremely rare. To our knowledge, only four cases of microbiologically confirmed ITSE have been reported in the English literature to date. Most cases have arisen in patients with pulmonary tuberculosis regardless of trauma. A 46-year-old man presented to the emergency department after a fall. On arrival, he complained of pain in his head, face, chest and left arm. He was alert and oriented. An initial neurological examination was normal. Radiologic evaluation revealed multiple fractures of his skull, ribs, left scapula and radius. Though he had suffered extensive skull fractures of his cranium, maxilla, zygoma and orbital wall, the sustained cerebral contusion and hemorrhage were mild. Eighteen days later, he suddenly experienced a general tonic-clonic seizure. Radiologic evaluation revealed a subdural empyema in the left occipital area that was not present on admission. We performed a craniotomy, and the empyema was completely removed. Microbiological examination identified Mycobacterium tuberculosis (M. tuberculosis). After eighteen months of anti-tuberculous treatment, the empyema disappeared completely. This case demonstrates that tuberculosis can induce empyema in patients with skull fractures. Thus, we recommend that M. tuberculosis should be considered as the probable pathogen in cases with posttraumatic empyema. PMID:27226867

  5. Stereoscopic three-dimensional images of an anatomical dissection of the eyeball and orbit for educational purposes.

    PubMed

    Matsuo, Toshihiko; Takeda, Yoshimasa; Ohtsuka, Aiji

    2013-01-01

    The purpose of this study was to develop a series of stereoscopic anatomical images of the eye and orbit for use in the curricula of medical schools and residency programs in ophthalmology and other specialties. Layer-by-layer dissection of the eyelid, eyeball, and orbit of a cadaver was performed by an ophthalmologist. A stereoscopic camera system was used to capture a series of anatomical views that were scanned in a panoramic three-dimensional manner around the center of the lid fissure. The images could be rotated 360 degrees in the frontal plane and the angle of views could be tilted up to 90 degrees along the anteroposterior axis perpendicular to the frontal plane around the 360 degrees. The skin, orbicularis oculi muscle, and upper and lower tarsus were sequentially observed. The upper and lower eyelids were removed to expose the bulbar conjunctiva and to insert three 25-gauge trocars for vitrectomy at the location of the pars plana. The cornea was cut at the limbus, and the lens with mature cataract was dislocated. The sclera was cut to observe the trocars from inside the eyeball. The sclera was further cut to visualize the superior oblique muscle with the trochlea and the inferior oblique muscle. The eyeball was dissected completely to observe the optic nerve and the ophthalmic artery. The thin bones of the medial and inferior orbital wall were cracked with a forceps to expose the ethmoid and maxillary sinus, respectively. In conclusion, the serial dissection images visualized aspects of the local anatomy specific to various procedures, including the levator muscle and tarsus for blepharoptosis surgery, 25-gauge trocars as viewed from inside the eye globe for vitrectomy, the oblique muscles for strabismus surgery, and the thin medial and inferior orbital bony walls for orbital bone fractures.

  6. Investigation of blast-induced fracture in rock mass using reversed vertical seismic profiling

    NASA Astrophysics Data System (ADS)

    Zou, D. H.; Wu, Y. K.

    2001-10-01

    The rock mass on quarry and pit wall surfaces is usually fractured during production blasting. Quantitative investigations of the fractured zones are needed for stabilization of the rock walls. In this study, the principle of reversed vertical seismic profiling (RVSP) was applied. A set of seismic geophones were arranged on the horizontal bench surface and seismic signals were generated along the vertical rock wall using a free-swinging hammer. The travel times of seismic rays were recorded and the P-wave velocities of the rock mass were analyzed using the Simultaneous Iterative Reconstruction Technique (SIRT). A series of site tests have been carried out on the rock walls at a granite quarry that are characterized by fractures. The fracture depth at various locations on the wall surface is thereby determined. The results indicate that RVSP provides an easy and reliable method to quantitatively evaluate the blasting-induced fractures in the rock mass.

  7. Orbital Compartment Syndrome Leading to Visual Loss following Orbital Floor Reconstruction.

    PubMed

    Susarla, Srinivas M; Nam, Arthur J; Dorafshar, Amir H

    2016-06-01

    Reconstruction of posttraumatic orbital defects carries the attendant risk of injury to the ocular adnexa, globe, and associated neurovascular structures. Blindness following repair of orbital fractures is an infrequent but well-documented phenomenon. Visual acuity loss can be related to direct intraoperative injury to the optic nerve, retinal arterial occlusion, or delayed presentation of acute optic nerve injury. In this report, we document a unique case of acute optic nerve infarction occurring 14 hours following orbital floor exploration and repair in a 56-year-old man.

  8. Olivine-Bearing Dune Fields and Wall Rock in Coprates Chasma

    NASA Image and Video Library

    2013-05-01

    In this image from NASA Mars Reconnaissance Orbiter, lower wall rock spurs are found that spread dark materials onto a dune field, suggesting local wall materials are a nearby sediment source for dunes.

  9. Crater Wall With Gullies

    NASA Technical Reports Server (NTRS)

    2004-01-01

    8 June 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows gullies formed in the terraced wall of an impact crater on the floor of a larger crater near 39.1oS, 200.7oW. Gullies such as these are fairly common in craters and depressions at southern middle latitudes. They also occur in some areas at northern middle latitudes and in both polar regions. They may have formed by liquid water, or not--the Mars science community is still debating and discussing the issue. This picture covers an area about 3 km (1.9 mi) across. The scene is illuminated by sunlight from the upper left.

  10. Crater Wall With Gullies

    NASA Technical Reports Server (NTRS)

    2004-01-01

    8 June 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows gullies formed in the terraced wall of an impact crater on the floor of a larger crater near 39.1oS, 200.7oW. Gullies such as these are fairly common in craters and depressions at southern middle latitudes. They also occur in some areas at northern middle latitudes and in both polar regions. They may have formed by liquid water, or not--the Mars science community is still debating and discussing the issue. This picture covers an area about 3 km (1.9 mi) across. The scene is illuminated by sunlight from the upper left.

  11. Orbiter/launch system

    NASA Technical Reports Server (NTRS)

    Jackson, L. R.; Weidner, J. P.; Small, W. J.; Martin, J. A. (Inventor)

    1981-01-01

    The system includes reusable turbojet propelled booster vehicles releasably connected to a reusable rocket powered orbit vehicle. The coupled orbiter-booster combination takes off horizontally and ascends to staging altitude and speed under booster power with both orbiter and booster wings providing lift. After staging, the booster vehicles fly back to Earth for horizontal landing and the orbiter vehicle continues ascending to orbit.

  12. Fracture Mechanics

    DTIC Science & Technology

    1974-01-31

    2219 -T851 aluminum (fractures at low stresses). The parameter KF is alloy compact specimens 1 2 and demonstrate consistent a function of specimen...Congress of 20. Walker, E. K., "The Effect of Stress Ratio Applied Mechanics, 1924. During Crack Propagation and Fatigue for 2024-T3 and 7015- T6 Aluminum ...34Stress- Corrosion Cracking in 12. Kaufman, J. G., and Nelson, F. G., "More Ti-6A1-4V Titanium Alloy in Nitrogen Tetroxide," on Specimen Size Effect in 2219

  13. Growth Plate Fractures

    MedlinePlus

    ... the most widely used by doctors is the Salter-Harris system, described below. Type I Fractures These ... incidence of growth plate fractures peaks in adolescence. Salter-Harris classification of growth plate fractures. AAOS does ...

  14. Hand fracture - aftercare

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000552.htm Hand fracture - aftercare To use the sharing features on ... need to be repaired with surgery. Types of Hand Fractures Your fracture may be in one of ...

  15. Kasei Valles Fractures

    NASA Image and Video Library

    2010-10-27

    The fracture system shown in this image from NASA Mars Odyssey is on the northern margin of the Kasei Valles lowland. Fractures like this can become chaos with continued downdropping of blocks and widening fractures.

  16. Ocular and orbital trauma from water balloon slingshots. A clinical, epidemiologic, and experimental study.

    PubMed

    Bullock, J D; Ballal, D R; Johnson, D A; Bullock, R J

    1997-05-01

    The authors report the findings of 17 patients with ophthalmic injuries produced by launched water balloons; they determine water balloon kinetic energies in experimental and theoretical studies. Six case summaries are presented; one case report was retrieved from the literature; ten injuries were reported to the Consumer Product Safety Commission. Energies were determined by field trials and calculations. Injuries included periorbital edema and ecchymoses, orbital contusions and hematomas, maxillary sinus hematomas, facial hypesthesia, eyelid lacerations, subconjunctival hemorrhages, corneal edema and abrasions, hyphemas, traumatic iritis, iris sphincter ruptures, iris atrophy, angle recession, iridodialysis, traumatic cataract, vitreous hemorrhages, retinal hemorrhages, macular hole formation, optic atrophy, and bony orbital wall fractures. Epidemiologic analysis revealed that children and young adults, more often males, were injured, most commonly in the warm weather months. In field trials, maximum water balloon velocities ranged from 38 to 41 m/sec (85-92 mph) with kinetic energies from 176 to 245 joules; by calculation, maximum velocities ranged from 42 to 54 m/sec (95-121 mph) with kinetic energies from 141 to 232 joules. In a field demonstration, a slingshot-launched water balloon exploded a watermelon. Energies are comparable to or greater than those experienced with a variety of common objects, including some rifle bullets that are known to cause serious ophthalmic injuries. These energies are far in excess of those required to perforate a cornea, rupture a globe, or fracture the bony orbit. This study demonstrates the serious and potentially vision- and life-threatening injuries inflicted by these "toys."

  17. 3D geostatistical modeling of fracture system in a granitic massif to characterize hydraulic properties and fracture distribution

    NASA Astrophysics Data System (ADS)

    Koike, Katsuaki; Kubo, Taiki; Liu, Chunxue; Masoud, Alaa; Amano, Kenji; Kurihara, Arata; Matsuoka, Toshiyuki; Lanyon, Bill

    2015-10-01

    This study integrates 3D models of rock fractures from different sources and hydraulic properties aimed at identifying relationships between fractures and permeability. The Tono area in central Japan, chiefly overlain by Cretaceous granite, was examined because of the availability of a unique dataset from deep borehole data at 26 sites. A geostatistical method (GEOFRAC) that can incorporate orientations of sampled data was applied to 50,900 borehole fractures for spatial modeling of fractures over a 12 km by 8 km area, to a depth of 1.5 km. GEOFRAC produced a plausible 3D fracture model, in that the orientations of simulated fractures correspond to those of the sample data and the continuous fractures appeared near a known fault. Small-scale fracture distributions with dominant orientations were also characterized around the two shafts using fracture data from the shaft walls. By integrating the 3D model of hydraulic conductivity using sequential Gaussian simulation with the GEOFRAC fractures from the borehole data, the fracture sizes and directions that strongly affect permeable features were identified. Four fracture-related elements: lineaments from a shaded 10-m DEM, GEOFRAC fractures using the borehole and shaft data, and microcracks from SEM images, were used for correlating fracture attributes at different scales. The consistency of the semivariogram models of distribution densities was identified. Using an experimental relationship between hydraulic conductivity and fracture length, the fractures that typically affect the hydraulic properties at the drift scale were surmised to be in the range 100-200 m. These results are useful for a comprehensive understanding of rock fracture systems and their hydraulic characteristics at multiple scales in a target area.

  18. Emergence of Anomalous Transport in Stressed Rough Fractures

    NASA Astrophysics Data System (ADS)

    Kang, P. K.; Brown, S.; Alves da Silva, J.; Juanes, R.

    2015-12-01

    Fluid flow and tracer transport in fractured rock controls many natural and engineered processes in the geosciences, and therefore has been extensively studied. Geologic fractures, however, are always under significant overburden stress. While confining stress has been shown to impact fluid flow through rough-walled fractures in a fundamental way, studies of anomalous tracer transport at the scale of individual fractures have so far ignored the potential role of confining stress.Here, we report the emergence of anomalous (non-Fickian) transport through a rough-walled fracture as a result of increasing the normal stress on the fracture. We generate fracture surfaces with fractal roughness, and solve the elastic contact problem between the two surfaces to obtain the 3D fracture geometry for increasing levels of normal stress. We then simulate fluid flow and particle transport through the stressed rough fracture. We observe a transition from Fickian to anomalous transport as the normal stress on the fracture increases.We show that the origin of this anomalous transport behavior can be traced to the self-organization of the flow field into a heterogeneous structure dominated by preferential channels and stagnation zones, as a result of the larger number of contacts in a highly stressed fracture. We also propose a spatial Markov model that reproduces the transport behavior at the scale of the entire fracture with only three physical parameters. Our results point to a heretofore unrecognized link between geomechanics and anomalous particle transport in fractured media. Finally, we show preliminary laboratory experiment results that confirm our findings. (a) Magnitude of the volumetric flux at each discretization grid block at low stress. (b) Magnitude of the volumetric flux for a highly stressed fracture. Values are normalized with the mean volumetric flux.

  19. Altered disc pressure profile after an osteoporotic vertebral fracture is a risk factor for adjacent vertebral body fracture

    PubMed Central

    Tzermiadianos, Michael N.; Renner, Susan M.; Phillips, Frank M.; Hadjipavlou, Alexander G.; Zindrick, Michael R.; Havey, Robert M.; Voronov, Michael

    2008-01-01

    This study investigated the effect of endplate deformity after an osteoporotic vertebral fracture in increasing the risk for adjacent vertebral fractures. Eight human lower thoracic or thoracolumbar specimens, each consisting of five vertebrae were used. To selectively fracture one of the endplates of the middle VB of each specimen a void was created under the target endplate and the specimen was flexed and compressed until failure. The fractured vertebra was subjected to spinal extension under 150 N preload that restored the anterior wall height and vertebral kyphosis, while the fractured endplate remained significantly depressed. The VB was filled with cement to stabilize the fracture, after complete evacuation of its trabecular content to ensure similar cement distribution under both the endplates. Specimens were tested in flexion-extension under 400 N preload while pressure in the discs and strain at the anterior wall of the adjacent vertebrae were recorded. Disc pressure in the intact specimens increased during flexion by 26 ± 14%. After cementation, disc pressure increased during flexion by 15 ± 11% in the discs with un-fractured endplates, while decreased by 19 ± 26.7% in the discs with the fractured endplates. During flexion, the compressive strain at the anterior wall of the vertebra next to the fractured endplate increased by 94 ± 23% compared to intact status (p < 0.05), while it did not significantly change at the vertebra next to the un-fractured endplate (18.2 ± 7.1%, p > 0.05). Subsequent flexion with compression to failure resulted in adjacent fracture close to the fractured endplate in six specimens and in a non-adjacent fracture in one specimen, while one specimen had no adjacent fractures. Depression of the fractured endplate alters the pressure profile of the damaged disc resulting in increased compressive loading of the anterior wall of adjacent vertebra that predisposes it to wedge fracture. This data suggests that

  20. Dissolution and precipitation of fractures in soluble rock

    NASA Astrophysics Data System (ADS)

    Kaufmann, Georg; Gabrovšek, Franci; Romanov, Douchko

    2016-04-01

    Soluble rocks such as limestone, anhydrite, and gypsum are characterised by their large secondary permeability, which results from the interaction of water circulating through the rock and dissolving the soluble fracture walls. This highly selective dissolution process enlarges the fractures to voids and eventually cavities, which then carry the majority of flow through an aquifer along preferential flow pathes. We employ a numerical model describing the evolution of secondary porosity in a soluble rock to discuss the evolution of single fractures in different rock types. Our main focus is three-fold: The distinction of shallow versus deep flow pathes and their evolution on the one hand; the effect of precipitation of the dissolved material in the fracture, and finally the complication of fracture enlargement in fractures composed of several different soluble materials. We observe a similar evolution of void space for fractures composed of limestone and gypsum, but on different time scales. For anhydrite, owing to its difference in the kinetical rate law describing the removal of soluble rock, when compared to limestone and anhydrite, the evolution is even faster. Precipitation of the dissolved rock due to changes in the hydrochemical conditions can clog fractures fairly fast, thus changing the pattern of preferential pathways in the soluble aquifer, especially with depth. Finally, limestone fractures coated with gypsum, as frequently observed in caves, will result in a substantial acceleration of fracture enlargement with time, thus giving these fractures a hydraulical advantage over pure limestone fractures in their competition for capturing flow.

  1. Fluid and particulate suspension flows at fracture junctions

    NASA Astrophysics Data System (ADS)

    Lo, Tak S.; Koplik, Joel

    2015-03-01

    Suspended particles can be a serious problem in geological contexts such as fluid recovery from reservoirs because they alter the rheology of the flowing liquids and may obstruct transport by narrowing flow channels due to deposition or gravitational sedimentation. In particular, the irregular geometry of the fracture walls can trap particles, induce jamming and cause unwanted channeling effects. We have investigated particle suspension flows in tight geological fractures using lattice Boltzmann method in the past. In this work we extend these studies to flows at a junction where two fractures intersect, an essential step towards a complete understanding of flows in fracture networks. The fracture walls are modeled as realistic self-affine fractal surfaces, and we focus on the case of tight fractures, where the wall roughness, the aperture and the particle size are all comparable. The simulations provide complete detail on the particle configurations and the fluid flow field, from which the stresses in the fluid and the forces acting on the bounding walls can be computed. With these information, phenomena such as particle mixing and dispersion, mechanical responses of the solid walls, possible jamming and release at junctions, and other situations of interest can be investigated. Work supported by NERSC and DOE.

  2. ‘Sutureless’ transconjunctival approach for infraorbital rim fractures

    PubMed Central

    Nagaraj, Vaibhav; Ghosh, Abhishek; Nanjappa, Madan; Ramesh, Keerthi

    2015-01-01

    Aim: To analyze the ease and surgical outcome of using sutureless transconjunctival approach for repair of infra-orbital fractures. Design: Prospective clinical case series. Materials and Methods: Totally 5 patients with infra-orbital rim or orbital floor fractures were selected and the fractures were accessed through a pre-septal transconjunctival incision. After reduction and fixation, the conjunctiva was just re-approximated and re-draped into position. Incidence of post-operative complications such as diplopia, lid retraction, eyelid dystopia, foreign body granuloma and poor conjunctival healing was assessed at intervals of 1 week, 15 days and a month post-operatively. Results: No complications were observed in any of the 5 patients. Healing was satisfactory in all patients. Conclusion: The sutureless technique appears to be a time saving and technically simpler viable alternative to multilayered suturing in orbital trauma with minimal post-operative complications. PMID:25821377

  3. The Revised Direct Transconjunctival Approach to the Orbital Floor.

    PubMed

    Bernardini, Francesco P; Nerad, Jeffrey; Fay, Aaron; Zambelli, Alessandra; Cruz, Antonio Augusto V

    To review common surgical approaches to the orbital floor and to evaluate the utility of canthal-sparing, single incision transconjunctival method. A retrospective chart review of a consecutive series of patients who underwent transconjunctival, direct incision surgery without eyelid dissection or lateral canthotomy and inferior cantholysis and review of the literature were conducted. Twenty-three consecutive patients (33 orbits) were operated using a canthal-sparing direct single cut approach, including 10 unilateral pediatric orbital floor fractures, 1 orbital floor implant removal, 2 unilateral post-traumatic enophthalmos repairs, and 10 bilateral orbital floor decompressions. Surgical exposure was adequate to complete the surgical objective in each patient. Mean follow up was 13 months and no complications were observed. The transconjunctival approach to the orbital floor can be performed using a pre- or post-septal dissection, with infratarsal or fornix incision commonly associated with lateral canthotomy and inferior cantholysis. The direct approach spares the lateral canthus, minimizes lower eyelid dissection, and provides rapid and effective access to the inferior orbital rim and orbital floor. It offers sufficient exposure to allow insertion of large floor implants even in children. Although apparently abandoned in the recent literature, canthal-sparing technique is a useful method for the management of orbital floor fractures, enophthalmos correction, implant removal, and orbital decompression.

  4. NASGRO(registered trademark): Fracture Mechanics and Fatigue Crack Growth Analysis Software

    NASA Technical Reports Server (NTRS)

    Forman, Royce; Shivakumar, V.; Mettu, Sambi; Beek, Joachim; Williams, Leonard; Yeh, Feng; McClung, Craig; Cardinal, Joe

    2004-01-01

    This viewgraph presentation describes NASGRO, which is a fracture mechanics and fatigue crack growth analysis software package that is used to reduce risk of fracture in Space Shuttles. The contents include: 1) Consequences of Fracture; 2) NASA Fracture Control Requirements; 3) NASGRO Reduces Risk; 4) NASGRO Use Inside NASA; 5) NASGRO Components: Crack Growth Module; 6) NASGRO Components:Material Property Module; 7) Typical NASGRO analysis: Crack growth or component life calculation; and 8) NASGRO Sample Application: Orbiter feedline flowliner crack analysis.

  5. Cooling wall

    SciTech Connect

    Nosenko, V.I.

    1995-07-01

    Protecting the shells of blast furnaces is being resolved by installing cast iron cooling plates. The cooling plates become non-operational in three to five years. The problem is that defects occur in manufacturing the cooling plates. With increased volume and intensity of work placed on blast furnaces, heat on the cast iron cooling plates reduces their reliability that limits the interim repair period of blast furnaces. Scientists and engineers from the Ukraine studied this problem for several years, developing a new method of cooling the blast furnace shaft called the cooling wall. Traditional cast iron plates were replaced by a screen of steel tubes, with the area between the tubes filled with fireproof concrete. Before placing the newly developed furnace shaft into operation, considerable work was completed such as theoretical calculations, design, research of temperature fields and tension. Continual testing over many years confirms the value of this research in operating blast furnaces. The cooling wall works with water cooling as well as vapor cooling and is operating in 14 blast furnaces in the Ukraine and two in Russia, and has operated for as long as 14 years.

  6. Chopart fractures.

    PubMed

    Klaue, Kaj

    2004-09-01

    The Chopart articular space was described by François Chopart (1743-1795) as a practical space for amputations in cases of distal foot necrosis. It corresponds to the limit between the anatomical hind-foot and the mid-foot. The bones involved are the talus and the calcaneus proximally, and the navicular and the cuboid distally. This space thus holds two functionally distinct entities, the anterior part of the coxa pedis (an essential functional joint) and the calcaneo-cuboidal joint,which can be considered to be an "adaptive joint" within a normal foot. Trauma to this region may cause fractures and/or dislocations and, in high energy trauma,compartment syndromes. Principles of treatment are immediate reduction of dislocations and realignment of the medial and lateral column of the foot in length and orientation. Open reduction and internal fixation of talus and navicular fractures are often indicated to restore the "coxa pedis". Open reconstruction or fusion in correct length of the calcaneo-cuboidal joint is occasionally indicated. Salvage procedures in malunions include navicular osteotomies and calcaneo-cuboidal bone block fusions. Treatment of joint destructions, especially involving the talo-navicular joint, include triple arthrodesis.

  7. [Pre- and postoperative ocular blood flow in transconjunctival orbital surgery].

    PubMed

    Grusha, Ia O; Kiseleva, T N; Danilov, S S; Markosian, A G

    2014-01-01

    to evaluate the pre- and postoperative ocular blood flow in patients with post-traumatic orbital deformities who underwent transconjunctival orbital reconstruction. A total of 40 patients with post-traumatic deformities of the inferior and medial orbital walls were examined before and after transconjunctival "Alloplant" implantation to the orbit. Before the surgery, blood flow deficiency in a. ophthalmica and elevation in peripheral vascular resistance were found in all patients. Postoperatively, orbital hemodynamic parameters were restored and remained stable over the whole follow-up period. Post-traumatic disturbances of regional blood flow are revealed and postoperative changes of the relevant parameters are assessed.

  8. Surface deformation from a pressurized subsurface fracture: Problem description

    SciTech Connect

    Fu, Pengcheng

    2014-09-15

    This document speci es a set of problems that entail the calculation of ground surface deformation caused by a pressurized subsurface fracture. The solid medium is assumed to be isotropic-homogeneous where linear elasticity applies. The e ects of the uid in the fracture is represented by a uniform pressure applied onto the two fracture walls. The fracture is assumed to be rectangular in shape and various dipping angles are considered. In addition to the full 3D solution, we reduce the 3D problem to a plane-strain geometry, so that 2D codes can participate in the comparison and results can be compared with those available in the literature.

  9. Controversies in Treatment of Acetabular Fracture

    PubMed Central

    Grubor, Predrag; Krupic, Ferid; Biscevic, Mirza; Grubor, Milan

    2015-01-01

    Introduction: Acetabular fractures treatment represents a great controversy, challenge and dilemma for an orthopedic surgeon. Aim: The aim of the paper was to present the results of treatment of 96 acetabular fractures in the Clinic of Traumatology Banja Luka, in the period from 2003 to 2013, as well as to raise awareness regarding the controversy in the methods of choice in treating acetabulum fractures. Material and methods: The series consists of 96 patients, 82 males and 14 females, average age 40.5 years. Traffic trauma was the cause of fractures in 79 patients (85%), and in 17 patients (15%) fractures occurred due to falls from height. Polytrauma was present in 31 patients (32%). According to the classification of Judet and Letournel, representation of acetabular fractures was as follows: posterior wall in 32 patients, posterior column in 28, anterior wall in 4, anterior column in 2, transverse fractures in 8, posterior wall and posterior column in 10, anterior and posterior wall in 6, both- column in 4 and transversal fracture and posterior wall in 2 patients. 14 patients were treated with traction, that is, 6 patients with femoral traction and 8 patients with both lateral and femoral traction. 82 patients (86.4%) were surgically treated. Kocher-Langenbeck approach was applied in the treatment of 78 patients. In two patients from the Kocher-Langenbeck’s approach, the Ollier’s approach had to be applied as well. Two acetabular were primarily treated with Ollier’s approach. Extended Smith- Peterson’s approach was applied 4 times, and Emile Letournel’s (ilioinguinal) approach 14 times. Results: Functional outcome (after follow-up of 18 months), according to the Harris hip score of surgical treatment in 82 patients, was as follows: good 46 (56%), satisfactory 32 (39%) and poor 4 (5%). Results of acetabulum fractures treated with traction were: good 8 (57%), satisfactory 4 (28%) and poor 2 (15%). According to the Brook’s classification of heterotopic

  10. Arrangement of peptidoglycan in the cell wall of Staphylococcus spp.

    PubMed Central

    Amako, K; Umeda, A; Murata, K

    1982-01-01

    The arrangement of peptidoglycan in the cell wall of Staphylococcus was observed with the newly developed freeze-fracture technique, using n-octanol instead of water as the freezing medium. The replica of the trichloroacetic acid-extracted cell wall (TCA-wall) showed two areas. One of them has a concentric circular structure, a characteristic surface structure of the staphylococcal cell wall, and the other showed an irregular and rough surface. The chemical analysis of the wall revealed that the TCA-wall consisted of mostly peptidoglycan. By digesting the TCA-wall with lysozyme, the circular structures were greatly disturbed, and they disappeared after 60 min of treatment. From these observations it can be expected that the peptidoglycan is arranged in a concentric circular manner in the newly generated cell wall of Staphylococcus. Images PMID:7068534

  11. Fracture strength and fracture patterns of root filled teeth restored with direct resin restorations.

    PubMed

    Taha, N A; Palamara, J E; Messer, H H

    2011-08-01

    To compare fracture characteristics of root-filled teeth with variable cavity design and resin composite restoration. 80 extracted intact maxillary premolars were divided randomly into eight groups; (1) intact teeth; (2) unrestored MOD cavity; (3) unrestored MOD cavity plus endodontic access through the occlusal floor; (4) unrestored MOD plus endodontic access with axial walls removed; (5) MOD restored with resin composite; (6) MOD plus endodontic access, resin composite; (7) MOD plus extensive endodontic access, resin composite; (8) MOD plus extensive endodontic access, GIC core and resin composite. A ramped oblique load was applied to the buccal cusp in a servohydraulic testing machine. Fracture load and fracture patterns were recorded. Fracture loads were compared statistically using 1-way ANOVA, with Dunnett test for multiple comparisons. Unrestored teeth became progressively weaker with more extensive preparations. Endodontic access confined within the occlusal floor did not significantly affect strength compared to an MOD cavity. Loss of axial walls weakened teeth considerably [292+80N vs 747+130N for intact teeth]. Restoration increased the strength of prepared teeth particularly in teeth without axial walls. Teeth with a GIC core were not significantly weaker than intact teeth [560+167N]. Failures were mostly adhesive at the buccal interface, with the fracture propagating from the buccal line angle of the occlusal floor (MOD and MOD plus access groups) or of the proximal box (axial wall removed). Direct restorations increased fracture resistance of root filled teeth with extensive endodontic access. Both restored and unrestored teeth showed similar fracture patterns. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Characterization of midface fractures incurred in recent wars.

    PubMed

    Kittle, Christopher P; Verrett, Adam J; Wu, Jesse; Mellus, Davin E; Hale, Robert G; Chan, Rodney K

    2012-11-01

    Facial injuries sustained by US military personnel during the wars in Iraq and Afghanistan have increased compared with past conflicts. Characterization of midface fractures (orbits, maxilla, zygoma, and nasal bones) sustained on the battlefield is needed to improve our understanding of these injuries, to optimize treatment, and to potentially direct strategic development of protective equipment in the future. The military's Joint Theater Trauma Registry was queried for midface fractures from 2001 to 2011 using International Classification of Diseases, Ninth Revision diagnosis codes. Stratification was then performed, and individual treatment records from Brooke Army Medical Center were reviewed. Analysis of the fracture pattern, treatment, and complications was performed. One thousand seven hundred sixty individuals with midface fractures were identified. Those fractures sustained in battle were characterized by a predominance of open fractures, blast etiology, and associated injuries. Detailed record reviews of the patients treated at our institution revealed 45% of all midface fractures as operative. Thirty-one percent of these were treated at levels III and IV facilities outside the continental United States before arrival at our institution. Patients with midface fractures underwent multiple operations. There was a 30% rate of complication among operative fractures characterized by malalignment, implant exposure, and infection. Midface battle injuries also had a high incidence of orbital fractures and severe globe injuries. Midface fractures sustained in the battlefield have a high complication rate, likely as a result of the blast mechanism of injury with associated open fractures, multiple fractures, and associated injuries. These cases present unique challenges, often requiring both soft tissue and skeletal reconstruction.

  13. New instrument for orbital anthropometry.

    PubMed

    Kohout, M; Pai, L; Berenguer, B; Tayler, P; Pracharktam, N; Mulliken, J B

    1998-06-01

    A new instrument for orbital anthropometry is described. It consists of the base for a slit-lamp upon which the patient's head rests and rulers mounted on three independently movable axes. The z-axis probe is used to measure sagittal relationship between the corneal apices and points on the orbital perimeter. The instrument was tested against a sliding caliper and its accuracy was found to be within 0.2 mm or 2%. Intra- and inter-observer reliability were assessed by repeated measurements of two subjects by three observers. The intra-observer reliability was 0.99. Variations between observers was not significantly different for points orbitale inferius (oi), nasion (n), and orbitale superius (os), however, there was a statistically significant difference for measurement of orbitale laterale (ol). The correlation between anthropometric readings for lateral orbital wall to apex corneal (ol-ac) and CT scans for the same landmarks was assessed. Analysis of variance showed no difference between the measurement methods. This anthropometer is convenient and accurate for measurement of the sagittal orbital-globe relationships. A disadvantage is that it cannot be used intraoperatively.

  14. Detail view of the starboard mid deck wall of the ...

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

    Detail view of the starboard mid deck wall of the Orbiter Discovery showing Operational Sleeping Bags attached horizontally to the wall for the crew sleep period. If it is required as part of a mission's manifest a four-tiered rigid sleep station can be installed. This photograph was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  15. Wall to Wall Optimal Transport

    NASA Astrophysics Data System (ADS)

    Chini, Gregory P.; Hassanzadeh, Pedram; Doering, Charles R.

    2013-11-01

    How much heat can be transported between impermeable fixed-temperature walls by incompressible flows with a given amount of kinetic energy or enstrophy? What do the optimal velocity fields look like? We employ variational calculus to address these questions in the context of steady 2D flows. The resulting nonlinear Euler-Lagrange equations are solved numerically, and in some cases analytically, to find the maximum possible Nusselt number Nu as a function of the Péclect number Pe , a measure of the flow's energy or enstrophy. We find that in the fixed-energy problem Nu ~ Pe , while in the fixed-enstrophy problem Nu ~ Pe 10 / 17 . In both cases, the optimal flow consists of an array of convection cells with aspect ratio Γ (Pe) . Interpreting our results in terms of the Rayleigh number Ra for relevant buoyancy-driven problems, we find Nu <= 1 + 0 . 035 Ra and Γ ~ Ra - 1 / 2 for porous medium convection (which occurs with fixed energy), and Nu <= 1 + 0 . 115 Ra 5 / 12 and Γ ~ Ra - 1 / 4 for Rayleigh-Bénard convection (which occurs with fixed enstrophy and for free-slip walls). This work was supported by NSF awards PHY-0855335, DMS-0927587, and PHY-1205219 (CRD) and DMS-0928098 (GPC). Much of this work was completed at the 2012 Geophysical Fluid Dynamics (GFD) Program at Woods Hole Oceanographic Institution.

  16. Crustal Fractures of Ophir Planum

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 29 April 2002) The Science This THEMIS image covers a tract of plateau territory called Ophir Planum. The most obvious features in this scene are the fractures (ranging from 1 to 5 km wide) running from the upper left to lower right. Localized rifting and deep-seated tension fracturing of the crust probably formed these cracks. The wall rock displayed in the upper part of the cliffs appears to be layered. The southwest-facing wall of the largest and uppermost fracture has classic spur and gully topography. This type of topography is created by differing amounts of erosion. Also seen in this image are some scattered impact craters and some dark wind streaks in the lower right. The Ophir Planum plateau separates two separate smaller canyon systems, not visible in this image, (Candor Chasma to the north and Melas Chasma to the south) in the Valles Marineris canyon complex. The whole Valles Marineris canyon system extends some 4,000 km across the equatorial realms of Mars. For comparison, this would stretch from New York City to San Francisco. The Story Plateaus and spurs might make you think of cowboys on the open plain. 'Spurs' in this context, however, are simply ridges that can be seen on the side of the southwest-facing wall of the large fracture that splits the terrain. Gullies stretch down this slope as well. Both of these features are caused by erosion, which is a mild force of change compared to whatever tension cracked the crust and ripped apart the land. The wall rock displayed in the upper part of the cliffs appears to be layered, suggesting that different kinds of rocks and minerals can be found in each banded zone. The Ophir Planum plateau separates two separate canyon systems in the Valles Marineris complex, the largest canyon in the solar system. If Valles Marineris were on Earth, it would stretch from New York City all the way to San Francisco. That will give you some idea of the geological forces that have acted upon the planet over time

  17. Modelling of Local Necking and Fracture in Aluminium Alloys

    NASA Astrophysics Data System (ADS)

    Achani, D.; Eriksson, M.; Hopperstad, O. S.; Lademo, O.-G.

    2007-05-01

    Non-linear Finite Element simulations are extensively used in forming and crashworthiness studies of automotive components and structures in which fracture need to be controlled. For thin-walled ductile materials, the fracture-related phenomena that must be properly represented are thinning instability, ductile fracture and through-thickness shear instability. Proper representation of the fracture process relies on the accuracy of constitutive and fracture models and their parameters that need to be calibrated through well defined experiments. The present study focuses on local necking and fracture which is of high industrial importance, and uses a phenomenological criterion for modelling fracture in aluminium alloys. As an accurate description of plastic anisotropy is important, advanced phenomenological constitutive equations based on the yield criterion YLD2000/YLD2003 are used. Uniaxial tensile tests and disc compression tests are performed for identification of the constitutive model parameters. Ductile fracture is described by the Cockcroft-Latham fracture criterion and an in-plane shear tests is performed to identify the fracture parameter. The reason is that in a well designed in-plane shear test no thinning instability should occur and it thus gives more direct information about the phenomenon of ductile fracture. Numerical simulations have been performed using a user-defined material model implemented in the general-purpose non-linear FE code LS-DYNA. The applicability of the model is demonstrated by correlating the predicted and experimental response in the in-plane shear tests and additional plane strain tension tests.

  18. Effect of Natural Fractures on Hydraulic Fracturing

    NASA Astrophysics Data System (ADS)

    Ben, Y.; Wang, Y.; Shi, G.

    2012-12-01

    Hydraulic Fracturing has been used successfully in the oil and gas industry to enhance oil and gas production in the past few decades. Recent years have seen the great development of tight gas, coal bed methane and shale gas. Natural fractures are believed to play an important role in the hydraulic fracturing of such formations. Whether natural fractures can benefit the fracture propagation and enhance final production needs to be studied. Various methods have been used to study the effect of natural fractures on hydraulic fracturing. Discontinuous Deformation Analysis (DDA) is a numerical method which belongs to the family of discrete element methods. In this paper, DDA is coupled with a fluid pipe network model to simulate the pressure response in the formation during hydraulic fracturing. The focus is to study the effect of natural fractures on hydraulic fracturing. In particular, the effect of rock joint properties, joint orientations and rock properties on fracture initiation and propagation will be analyzed. The result shows that DDA is a promising tool to study such complex behavior of rocks. Finally, the advantages of disadvantages of our current model and future research directions will be discussed.

  19. Imaging of insufficiency fractures.

    PubMed

    Krestan, Christian R; Nemec, Ursula; Nemec, Stefan

    2011-07-01

    This review article focuses on occurrence, imaging, and differential diagnosis of insufficiency fractures. Prevalence and the most common sites of insufficiency fractures and their clinical implications are discussed. Insufficiency fractures are due to normal stress exerted on weakened bone. Most commonly postmenopausal osteoporosis is the cause for insufficiency fractures. Additional conditions affecting bone turnover include osteomalacia, chronic renal failure, and high-dose corticosteroid therapy. It is a challenge for the radiologist to detect and diagnose insufficiency fractures as well as to differentiate them from malignant fractures. Radiographs are the basic modality used for screening of insufficiency fractures, yet depending on the location of the fractures, sensitivity is limited. Magnetic resonance imaging is a very sensitive tool to visualize bone marrow abnormalities associated with insufficiency fractures and allows differentiation of benign versus malignant fractures. Thin section multidetector computed tomography (CT) depicts subtle fracture lines allowing direct visualization of cortical and trabecular bone. Dedicated Mikro-CTs (Xtreme-CT) can detect subtle fractures reaching an in-plane resolution of 80 μm. Bone scintigraphy still plays a role in detecting fractures, with good sensitivity but unsatisfactory specificity. Positron emission tomography-CT with hybrid-scanners has been the upcoming modality for the differentiation of benign from malignant fractures. Bone densitometry and clinical fracture history may determine the future risk of possible insufficiency fractures. © Thieme Medical Publishers.

  20. Fracture channel waves

    NASA Astrophysics Data System (ADS)

    Nihei, Kurt T.; Yi, Weidong; Myer, Larry R.; Cook, Neville G. W.; Schoenberg, Michael

    1999-03-01

    The properties of guided waves which propagate between two parallel fractures are examined. Plane wave analysis is used to obtain a dispersion equation for the velocities of fracture channel waves. Analysis of this equation demonstrates that parallel fractures form an elastic waveguide that supports two symmetric and two antisymmetric dispersive Rayleigh channel waves, each with particle motions and velocities that are sensitive to the normal and tangential stiffnesses of the fractures. These fracture channel waves degenerate to shear waves when the fracture stiffnesses are large, to Rayleigh waves and Rayleigh-Lamb plate waves when the fracture stiffnesses are low, and to fracture interface waves when the fractures are either very closely spaced or widely separated. For intermediate fracture stiffnesses typical of fractured rock masses, fracture channel waves are dispersive and exhibit moderate to strong localization of guided wave energy between the fractures. The existence of these waves is examined using laboratory acoustic measurements on a fractured marble plate. This experiment confirms the distinct particle motion of the fundamental antisymmetric fracture channel wave (A0 mode) and demonstrates the ease with which a fracture channel wave can be generated and detected.

  1. Sclerosing idiopathic orbital inflammation.

    PubMed

    Brannan, Paul A; Kersten, Robert C; Kulwin, Dwight R

    2006-01-01

    A 5-year-old girl referred for orbital cellulitis was found to have a right orbital mass. Computed tomography revealed a mass occupying the inferotemporal orbit, extending into the maxillary sinus. Biopsy yielded a diagnosis of sclerosing idiopathic orbital inflammation. She was successfully treated with prednisone.

  2. HVI Ballistic Performance Characterization of Non-Parallel Walls

    NASA Technical Reports Server (NTRS)

    Bohl, William; Miller, Joshua; Christiansen, Eric

    2012-01-01

    The Double-Wall, "Whipple" Shield [1] has been the subject of many hypervelocity impact studies and has proven to be an effective shield system for Micro-Meteoroid and Orbital Debris (MMOD) impacts for spacecraft. The US modules of the International Space Station (ISS), with their "bumper shields" offset from their pressure holding rear walls provide good examples of effective on-orbit use of the double wall shield. The concentric cylinder shield configuration with its large radius of curvature relative to separation distance is easily and effectively represented for testing and analysis as a system of two parallel plates. The parallel plate double wall configuration has been heavily tested and characterized for shield performance for normal and oblique impacts for the ISS and other programs. The double wall shield and principally similar Stuffed Whipple Shield are very common shield types for MMOD protection. However, in some locations with many spacecraft designs, the rear wall cannot be modeled as being parallel or concentric with the outer bumper wall. As represented in Figure 1, there is an included angle between the two walls. And, with a cylindrical outer wall, the effective included angle constantly changes. This complicates assessment of critical spacecraft components located within outer spacecraft walls when using software tools such as NASA's BumperII. In addition, the validity of the risk assessment comes into question when using the standard double wall shield equations, especially since verification testing of every set of double wall included angles is impossible.

  3. Role of the maxillofacial surgeon in the management of severe ocular injuries after maxillofacial fractures

    PubMed Central

    Roccia, Fabio; Boffano, Paolo; Guglielmi, Valeria; Forni, Paolo; Cassarino, Emanuele; Nadalin, Juri; Fea, Antonio; Gerbino, Giovanni

    2011-01-01

    Aim: This study was designed to evaluate the incidence of severe ocular injuries associated to maxillofacial fractures and report their management in the Emergency Department. Patients and Methods: Among the 1779 patients admitted for maxillofacial fractures, those with partial or total loss of vision at the time of emergency consultation were included in the study. Data collected from the patients’ medical records included age, gender, mechanism of injury, location and type of facial fractures, type of ocular injuries and cause of blindness, methods of treatment, and days of hospitalization. Results: Forty patients (2.2%), 32 men and 8 women, ranging from 17 to 85 years of age, presented with severely reduced vision or blindness associated to fractures of the facial middle third with involvement of one or more orbital walls, mainly caused by motor vehicle and work accidents. In 18 patients, severe ocular injuries were determined by direct lesion of the globe, in 14 by direct or indirect traumatic optic neuropathy and in 8 by a retrobulbar hematoma. Direct lesion of the eyeball was treated by prompt repair or enucleation of the globe, though no or little recovery of vision was obtained. Ophthalmologic and/or maxillofacial treatment of the anterior compartment lesions of the eye allowed a partial or total recovery of the vision. A partial or total recovery of the vision was observed in almost all the patients with indirect traumatic optic neuropathy after administration of steroids according to NASCIS II protocol. Likewise, an evident improvement of the vision was obtained by immediate drainage of retrobulbar hematoma. Conclusions: Early diagnosis of the nature of the ophthalmic injury and treatment are important, and involvement of the ophthalmologist is mandatory. PMID:21769204

  4. Closeup view of the mid deck aft wall of the ...

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

    Close-up view of the mid deck aft wall of the Orbiter Discovery showing a mission specific configuration of stowage lockers within the modular system designed for maximum flexibility. This photograph was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  5. Operative Fixation of Rib Fractures Indications, Techniques, and Outcomes.

    PubMed

    Galos, David; Taylor, Benjamin; McLaurin, Toni

    2017-01-01

    Rib fractures are extremely common injuries and vary in there severity from single nondisplaced fractures to multiple segmental fractures resulting in flail chest and respiratory compromise. Historically, rib fractures have been treated conservatively with pain control and respiratory therapy. However this method may not be the best treatment modality in all situations. Operative fixation of select rib fractures has been increasing in popularity especially in patients with flail chest and respiratory compromise. Newer techniques use muscle sparing approaches and precontoured locking plate technology to obtain stable fixation and allow improved respiration. Current reports shows that rib fracture fixation offers the benefits of improved respiratory mechanics and improved pain control in the severe chest wall injury with resultant improvement in patient outcomes by decreasing time on the ventilator, time in the intensive care unit, and overall hospital length of stay.

  6. Orbital Dermoid Cyst: Classification and its Impact on Surgical Management.

    PubMed

    Eldesouky, Mohammed Ashraf; Elbakary, Molham Abdelhafez

    2016-09-06

    Analysis of different clinical types of orbital dermoid cyst, and studying the impact of preoperative classification on the proposed surgical procedure. A retrospective study of orbital dermoid cyst cases. The clinical and imaging data were reviewed. The different types of dermoid were recorded as superficial or deep, lateral or medial, exophytic or endophytic. The deep dermoids were classified according to their site and continuity of the cyst wall. The operative approach, intraoperative, and/or postoperative complications were recorded. The study included 153 cases of orbital dermoid. The superficial lesions represented 68.6%, of which 74.3% were lateral and 61.0% were endophytic. Intraoperative cyst perforation was recorded in 56.3% of exophytic cases approached through crease incision, and recurrence occurred in 6.3%. Defective cyst wall was found in 31.25% of deep orbital dermoid. Surgery was complicated by cyst rupture when excision was attempted, and recurrence was recorded in one case. Exposure, intended evacuation, and dissection of the cyst wall were better surgical approaches for these cases without reported complications. Preoperative classification of orbital dermoid had an important effect on the surgical procedure. Endophytic superficial lesions were approached through crease incision without complications, while exophytic lesions were better approached through infrabrow incision. Deep orbital lesions with defective wall were better approached through exposure, intended evacuation, dissection, and excision of the remaining cyst wall.

  7. Synkinematic quartz cementation in partially open fractures in sandstones

    NASA Astrophysics Data System (ADS)

    Ukar, Estibalitz; Laubach, Stephen E.; Fall, Andras; Eichhubl, Peter

    2014-05-01

    Faults and networks of naturally open fractures can provide open conduits for fluid flow, and may play a significant role in hydrocarbon recovery, hydrogeology, and CO2 sequestration. However, sandstone fracture systems are commonly infilled, at least to some degree, by quartz cement, which can stiffen and occlude fractures. Such cement deposits can systematically reduce the overall permeability enhancement due to open fractures (by reducing open fracture length) and result in permeability anisotropies. Thus, it is important to identify the factors that control the precipitation of quartz in fractures in order to identify potential fluid conduits under the present-day stress field. In many sandstones, quartz nucleates syntaxially on quartz grain or cement substrate of the fracture wall, and extends between fracture walls only locally, forming pillars or bridges. Scanning electron microscope cathodoluminescence (SEM-CL) images reveal that the core of these bridges are made up of bands of broken and resealed cement containing wall-parallel fluid inclusion planes. The fluid inclusion-rich core is usually surrounded by a layer of inclusion-poor clear quartz that comprises the lateral cement. Such crack-seal textures indicate that this phase was precipitating while the fractures were actively opening (synkinematic growth). Rapid quartz accumulation is generally believed to require temperatures of 80°C or more. Fluid inclusion thermometry and Raman spectroscopy of two-phase aqueous fluid-inclusions trapped in crack-seal bands may be used to track the P-T-X evolution of pore fluids during fracture opening and crack-seal cementation of quartz. Quartz cement bridges across opening mode fractures in the Cretaceous Travis Peak Formation of the tectonically quiescent East Texas Basin indicate individual fractures opened over a 48 m.y. time span at rates of 16-23 µm/m.y. Similarly, the Upper Cretaceous Mesaverde Group in the Piceance Basin, Colorado contains fractures that

  8. Ocular and orbital trauma from water balloon slingshots: a clinical, epidemiological, experimental, and theoretical study.

    PubMed Central

    Bullock, J D; Johnson, D A; Ballal, D R; Bullock, R J

    1996-01-01

    PURPOSE: To report the clinical findings of 17 patients with ocular/orbital injuries produced by launched water balloons; to determine water balloon kinetic energies in experimental and theoretical studies. METHODS: Six case histories are presented, 1 case was retrieved from the medical literature, and 10 cases were reported to the National Injury Information Clearinghouse of the United States Consumer Product Safety Commission. The energies were determined by field trials and calculations. RESULTS: Injuries included orbital contusions and hematomas, facial hypesthesia, eyelid lacerations, subconjunctival hemorrhages, corneal edema and abrasion, hyphemas, traumatic iritis, iris sphincter ruptures, iris atrophy, angle recession, iridodialyses, traumatic cataract, vitreous hemorrhages, retinal hemorrhages, macular hole formation, optic atrophy, and bony orbital wall fractures. Epidemiological analysis revealed that children and young adults, more often males, were injured, most commonly in the warm weather months (May through September). In field trials, maximum water balloon velocities ranged from 38 to 41 m/sec (85 to 92 mph) with kinetic energies from 176 to 245 J; by calculation, maximum velocities ranged from 42 to 54 m/sec (95 to 121 mph) with kinetic energies from 141 to 232 J. In a field demonstration a 300-g water balloon launched horizontally from a distance of 20 ft exploded a 12-kg watermelon. Classic physics calculations are presented to explain the complex bio-mechanical interactions between the water balloon and the eye. CONCLUSION: Kinetic energies of launched water balloons are comparable to or greater than kinetic energies experienced with a variety of common objects, including file bullets, which are well known to cause serious ocular and orbital injuries. In addition, these energies are far in excess of those required to perforate a cornea (0.7 to 1.7 J), rupture a globe (1 to 5.3 J), or fracture the bony orbit (1.8 to 14.7 j). Thus, this study

  9. [Periprosthetic Acetabulum Fractures].

    PubMed

    Schreiner, A J; Stuby, F; de Zwart, P M; Ochs, B G

    2016-12-01

    In contrast to periprosthetic fractures of the femur, periprosthetic fractures of the acetabulum are rare complications - both primary fractures and fractures in revision surgery. This topic is largely under-reported in the literature; there are a few case reports and no long term results. Due to an increase in life expectancy, the level of patients' activity and the number of primary joint replacements, one has to expect a rise in periprosthetic complications in general and periprosthetic acetabular fractures in particular. This kind of fracture can be intra-, peri- or postoperative. Intraoperative fractures are especially associated with insertion of cementless press-fit acetabular components or revision surgery. Postoperative periprosthetic fractures of the acetabulum are usually related to osteolysis, for example, due to polyethylene wear. There are also traumatic fractures and fractures missed intraoperatively that lead to some kind of insufficiency fracture. Periprosthetic fractures of the acetabulum are treated conservatively if the implant is stable and the fracture is not dislocated. If surgery is needed, there are many possible different surgical techniques and challenging approaches. That is why periprosthetic fractures of the acetabulum should be treated by experts in pelvic surgery as well as revision arthroplasty and the features specific to the patient, fracture and prosthetic must always be considered. Georg Thieme Verlag KG Stuttgart · New York.

  10. Use of Orbital Conformer to Improve Speech in Patients with Confluent Maxillectomy and Orbital Defects.

    PubMed

    Colebeck, Amanda C; Kase, Michael T; Nichols, Cindy B; Golden, Marjorie; Huryn, Joseph M

    2016-04-01

    The basic objective in prosthetic restoration of confluent maxillary and orbital defects is to achieve a comfortable, cosmetically acceptable prosthesis that restores speech, deglutition, and mastication. It is a challenging task complicated by the size and shape of the defects. The maxillary obturator prosthesis often satisfies the objective of adequate deglutition; however, orbital defects that are not obturated in the medial, septal, or posterior walls allow air to escape, negatively impacting phonation. This article describes a technique to achieve favorable prosthetic rehabilitation in a patient with a maxillectomy and ipsilateral orbital exenteration. The prosthetic components include maxillary obturator, orbital conformer, and orbital prosthesis connected using rigid magnetic attachments. © 2015 by the American College of Prosthodontists.

  11. Transfer orbit determination accuracy for orbit maneuvers

    NASA Astrophysics Data System (ADS)

    Pinheiro, Mery Passos

    This work intends to show the accuracy of the orbital elements determined during transfer orbit as a function of data span, as well as the feasibility of performance maneuvers. The orbit estimator used is a weighted least squares algorithm. The observation vector is composed of angle data (azimuth and elevation) and range data and are from the Astra IC mission. The state vector is either propagated by Brower model or numerical integration (for small eccentricities and inclination). The complete software to determine the orbit has been developed by Hughes Aircraft and been used for all Hughes satellite mission.

  12. Lunar Reconnaissance Orbiter Orbit Determination Accuracy Analysis

    NASA Technical Reports Server (NTRS)

    Slojkowski, Steven E.

    2014-01-01

    Results from operational OD produced by the NASA Goddard Flight Dynamics Facility for the LRO nominal and extended mission are presented. During the LRO nominal mission, when LRO flew in a low circular orbit, orbit determination requirements were met nearly 100% of the time. When the extended mission began, LRO returned to a more elliptical frozen orbit where gravity and other modeling errors caused numerous violations of mission accuracy requirements. Prediction accuracy is particularly challenged during periods when LRO is in full-Sun. A series of improvements to LRO orbit determination are presented, including implementation of new lunar gravity models, improved spacecraft solar radiation pressure modeling using a dynamic multi-plate area model, a shorter orbit determination arc length, and a constrained plane method for estimation. The analysis presented in this paper shows that updated lunar gravity models improved accuracy in the frozen orbit, and a multiplate dynamic area model improves prediction accuracy during full-Sun orbit periods. Implementation of a 36-hour tracking data arc and plane constraints during edge-on orbit geometry also provide benefits. A comparison of the operational solutions to precision orbit determination solutions shows agreement on a 100- to 250-meter level in definitive accuracy.

  13. Two cases of orbital dystopia: Tessier III cleft and craniofacial osteomas.

    PubMed

    Furnas, D W; Achauer, B M

    1981-01-01

    Two cases of orbital dystopia are reported. One was caused by a Tessier III cleft and was treated by cranio-facial osteotomies of three walls of the orbit, allowing the left to be moved upward. The second involved multiple craniofacial osteomas and was treated by extractional osteotomies of four walls of the orbit including a transverse split of the roof. These osteotomies were entirely extramucosal.

  14. Paratrooper's ankle fracture: posterior malleolar fracture.

    PubMed

    Young, Ki Won; Kim, Jin-su; Cho, Jae Ho; Kim, Hyung Seuk; Cho, Hun Ki; Lee, Kyung Tai

    2015-03-01

    We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. Fifty-six members of the special force brigade of the military who had sustained ankle fractures during parachute landings between January 2005 and April 2010 were retrospectively analyzed. The injury sites and fracture sites were identified and the fracture types were categorized by the Lauge-Hansen and Weber classifications. Follow-up surveys were performed with respect to the American Orthopedic Foot and Ankle Society ankle-hindfoot score, patient satisfaction, and return to preinjury activity. The patients were all males with a mean age of 23.6 years. There were 28 right and 28 left ankle fractures. Twenty-two patients had simple fractures and 34 patients had comminuted fractures. The average number of injury and fractures sites per person was 2.07 (116 injuries including a syndesmosis injury and a deltoid injury) and 1.75 (98 fracture sites), respectively. Twenty-three cases (41.07%) were accompanied by posterior malleolar fractures. Fifty-five patients underwent surgery; of these, 30 had plate internal fixations. Weber type A, B, and C fractures were found in 4, 38, and 14 cases, respectively. Based on the Lauge-Hansen classification, supination-external rotation injuries were found in 20 cases, supination-adduction injuries in 22 cases, pronation-external rotation injuries in 11 cases, tibiofibular fractures in 2 cases, and simple medial malleolar fractures in 2 cases. The mean follow-up period was 23.8 months, and the average follow-up American Orthopedic Foot and Ankle Society ankle-hindfoot score was 85.42. Forty-five patients (80.36%) reported excellent or good satisfaction with the outcome. Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were compound fractures, most cases had to

  15. Paratrooper's Ankle Fracture: Posterior Malleolar Fracture

    PubMed Central

    Young, Ki Won; Cho, Jae Ho; Kim, Hyung Seuk; Cho, Hun Ki; Lee, Kyung Tai

    2015-01-01

    Background We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. Methods Fifty-six members of the special force brigade of the military who had sustained ankle fractures during parachute landings between January 2005 and April 2010 were retrospectively analyzed. The injury sites and fracture sites were identified and the fracture types were categorized by the Lauge-Hansen and Weber classifications. Follow-up surveys were performed with respect to the American Orthopedic Foot and Ankle Society ankle-hindfoot score, patient satisfaction, and return to preinjury activity. Results The patients were all males with a mean age of 23.6 years. There were 28 right and 28 left ankle fractures. Twenty-two patients had simple fractures and 34 patients had comminuted fractures. The average number of injury and fractures sites per person was 2.07 (116 injuries including a syndesmosis injury and a deltoid injury) and 1.75 (98 fracture sites), respectively. Twenty-three cases (41.07%) were accompanied by posterior malleolar fractures. Fifty-five patients underwent surgery; of these, 30 had plate internal fixations. Weber type A, B, and C fractures were found in 4, 38, and 14 cases, respectively. Based on the Lauge-Hansen classification, supination-external rotation injuries were found in 20 cases, supination-adduction injuries in 22 cases, pronation-external rotation injuries in 11 cases, tibiofibular fractures in 2 cases, and simple medial malleolar fractures in 2 cases. The mean follow-up period was 23.8 months, and the average follow-up American Orthopedic Foot and Ankle Society ankle-hindfoot score was 85.42. Forty-five patients (80.36%) reported excellent or good satisfaction with the outcome. Conclusions Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were

  16. Orbits: Computer simulation

    NASA Technical Reports Server (NTRS)

    Muszynska, A.

    1985-01-01

    In rotating machinery dynamics an orbit (Lissajous curve) represents the dynamic path of the shaft centerline motion during shaft rotation and resulting precession. The orbit can be observed with an oscilloscope connected to XY promixity probes. The orbits can also be simulated by a computer. The software for HP computer simulates orbits for two cases: (1) Symmetric orbit with four frequency components with different radial amplitudes and relative phase angles; and (2) Nonsymmetric orbit with two frequency components with two different vertical/horizontal amplitudes and two different relative phase angles. Each orbit carries a Keyphasor mark (one-per-turn reference). The frequencies, amplitudes, and phase angles, as well as number of time steps for orbit computation, have to be chosen and introduced to the computer by the user. The orbit graphs can be observed on the computer screen.

  17. Predicting zygoma fractures from baseball impact.

    PubMed

    Cormier, Joseph M; Stitzel, Joel D; Hurst, William J; Porta, David J; Jones, Jeryl; Duma, Stefan M

    2006-01-01

    The purpose of this study is to develop injury risk functions that predict zygoma fracture based on baseball type and impact velocity. Zygoma fracture strength data from published experiments were mapped with the force exerted by a baseball on the orbit as a function of ball velocity. Using a normal distribution, zygoma fracture risk functions were developed. Experimental evaluation of these risk functions was performed using six human cadaver tests and two baseballs of different stiffness values. High speed video measured the baseball impact velocity. Post test analysis of the cadaver skulls was performed using CT imaging including three-dimensional reconstruction as well as autopsy. The developed injury risk functions accurately identify the risk of zygoma fracture as a result of baseball impact. The experimental results validated the zygoma risk functions at the lower and upper levels. The injuries observed in the post test analysis included fractures of the zygomatic arch, frontal process and the maxilla, zygoma suture, with combinations of these creating comminuted, tripod fractures of the zygoma. Tests with a softer baseball did result in injury but these had fewer resulting zygoma bone fragments and occurred at velocities 50% higher than the major league ball.

  18. Facial fractures from dog bite injuries.

    PubMed

    Tu, Alexander H; Girotto, John A; Singh, Navin; Dufresne, Craig R; Robertson, Bradley C; Seyfer, Alan E; Manson, Paul N; Iliff, Nicholas

    2002-04-01

    Dog bites are commonly associated with soft-tissue injury to the face but rarely result in facial fractures. This article reports six new cases of facial fractures associated with dog bites and reviews additional cases reported in the literature. The demographics of the patients attacked, the location of facial fractures, and the characteristics of associated soft-tissue injuries or complications developing from the dog bite are described. With six new cases and 10 from the literature, this article reviewed a total of 16 cases involving 27 facial fractures. Eighty-seven percent of the cases involved children less than 16 years of age. The periorbital or nasal bones were involved in 69 percent of the cases. Lacerations were the most frequently associated soft-tissue injury. Additional injuries included facial nerve damage, lacrimal duct damage requiring stenting and reconstruction, ptosis from levator transection, and blood loss requiring transfusion. Although facial fractures are not commonly considered to be associated with dog bite injuries, the index of suspicion for a fracture should be raised when the injury occurs in a child, particularly when injury occurs near the orbit, nose, and cheek.

  19. [Fractures of the forefoot].

    PubMed

    Richter, M

    2011-10-01

    Fractures of the forefoot are common and comprise approximately two thirds of all foot fractures. Forefoot fractures are caused by direct impact or the effect of indirect force. The forces exerted can range from repetitive minor load (stress fractures) to massive destructive forces (complex trauma). The clinical course in forefoot fractures is typically more favourable than in fractures of the mid- and hindfoot. The incidence of complications like infection or pseudarthrosis is low. Exceptions are rare fractures of the proximal shaft of the fifth metatarsal and the sesamoids with higher pseudarthrosis rates. Malunited metatarsal fractures can cause painful conditions that should even be treated operatively. Differences in structure and function of the different forefoot areas and specific fracture types require an adapted management of these special injuries.

  20. Management of metacarpal fractures.

    PubMed

    McNemar, Thomas B; Howell, Julianne Wright; Chang, Eric

    2003-01-01

    Fractures of the hand are the most common fractures of the human skeleton. Metacarpal fractures account for 30% to 50% of all of hand fractures. The mechanisms of these injuries vary from axial loading forces to direct blows to the dorsal hand. Resulting deformities include malrotation, angulation, and shortening. Treatment modalities vary from nonoperative reduction to open reduction and internal fixation. The treatment algorithm is guided by the location of the fracture, the stability of the fracture, and the resultant deformity. Operative procedures, although they may lead to excellent radiographic reduction of fractures, often lead to debilitating stiffness from the inflammatory reaction of the surgical procedure. Operative fixation must be employed judiciously and offered only when confident that non-operative therapy can be improved on with operative intervention. This article reviews the various types of metacarpal fractures, with the treatment options available for each fracture. The indications for each treatment modality, postoperative care, and rehabilitation are presented.

  1. Pediatric Phalanx Fractures.

    PubMed

    Abzug, Joshua M; Dua, Karan; Bauer, Andrea Sesko; Cornwall, Roger; Wyrick, Theresa O

    2016-11-01

    Phalangeal fractures are the most common type of hand fracture that occurs in the pediatric population and account for the second highest number of emergency department visits for fractures in the United States. The incidence of phalangeal fractures is the highest in children aged 10 to 14 years, which coincides with the time that most children begin playing contact sports. Younger children are more likely to sustain a phalangeal fracture in the home setting as a result of crush and laceration injuries. Salter-Harris type II fractures of the proximal phalanx are the most common type of finger fracture. An unmineralized physis is biomechanically weaker compared with the surrounding ligamentous structures and mature bone, which makes fractures about the physis likely. A thorough physical examination is necessary to assess the digital cascade for signs of rotational deformity and/or coronal malalignment. Plain radiographs of the hand and digits are sufficient to confirm a diagnosis of a phalangeal fracture. The management of phalangeal fractures is based on the initial severity of the injury and depends on the success of closed reduction techniques. Nondisplaced phalanx fractures are managed with splint immobilization. Stable, reduced phalanx fractures are immobilized but require close monitoring to ensure maintenance of fracture reduction. Unstable, displaced phalanx fractures require surgical management, preferably via closed reduction and percutaneous pinning.

  2. Pediatric Phalanx Fractures.

    PubMed

    Abzug, Joshua M; Dua, Karan; Sesko Bauer, Andrea; Cornwall, Roger; Wyrick, Theresa O

    2017-02-15

    Phalangeal fractures are the most common type of hand fracture that occurs in the pediatric population and account for the second highest number of emergency department visits in the United States for fractures. The incidence of phalangeal fractures is the highest in children aged 10 to 14 years, which coincides with the time that most children begin playing contact sports. Younger children are more likely to sustain a phalangeal fracture in the home setting as a result of crush and laceration injuries. Salter-Harris type II fractures of the proximal phalanx are the most common type of finger fracture. An unmineralized physis is biomechanically weaker compared with the surrounding ligamentous structures and mature bone, which make fractures about the physis likely. A thorough physical examination is necessary to assess the digital cascade for signs of rotational deformity and/or coronal malalignment. Plain radiographs of the hand and digits are sufficient to confirm a diagnosis of a phalangeal fracture. The management of phalangeal fractures is based on the initial severity of the injury and depends on the success of closed reduction techniques. Nondisplaced phalanx fractures are managed with splint immobilization. Stable, reduced phalanx fractures are immobilized but require close monitoring to ensure maintenance of fracture reduction. Unstable, displaced phalanx fractures require surgical management, preferably via closed reduction and percutaneous pinning.

  3. Phase-averaged wall shear stress, wall pressure, and near-wall velocity field measurements in a whirling annular seal

    SciTech Connect

    Morrison, G.L.; Winslow, R.B.; Thames, H.D. III

    1996-07-01

    The flow field inside a 50 percent eccentric whirling annular seal operating at a Reynolds number of 24,000 and a Taylor number of 6600 has been measured using a three-dimensional laser-Doppler anemometer system. Flush mount pressure and wall shear stress probes have been used to measure the stresses (normal and shear) along the length of the stator. The rotor was mounted eccentrically on the shaft so that the rotor orbit was circular and rotated at the same speed as the shaft (a whirl ratio of 1.0). This paper presents mean pressure, mean wall shear stress magnitude, and mean wall shear stress direction distributions along the length of the seal. Phase-averaged wall pressure and wall shear stress are presented along with phase-averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall, where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure, and wall shear stress are very complex and do not follow simple bulk flow predictions.

  4. The prenatal development of the human orbit.

    PubMed

    de Haan, A B; Willekens, B; Klooster, J; Los, A A; van Zwieten, J; Botha, C P; Spekreijse, H; IJskes, S G; Simonsz, H J

    2006-03-01

    During the 1970s, as part of his work for a doctor's thesis in which he described the development of the human orbit in great detail, the first author established the largest anatomical collection of embryonic and fetal orbits ever. Unfortunately, he died before the thesis could be finished. The thousands of sections have now been scanned at high resolution and made publicly available on the Internet at www.visible-orbit.org; 3-D reconstruction software is being developed. The Discussion and part of the 'Methods' section of this thesis are published in translation in this article. The conclusions of the first author at the time read as follows: (1) initially, the developing orbit is vaguely indicated by condensations in the mesenchymal connective tissue area; (2) in this connective tissue area, chondral, osseous and muscular structures develop and grow until, in the fully developed stage, the orbital content is surrounded by bony surfaces with a thin layer of connective tissue as periosteum, and by a muscle fragment; (3) the embryonic and early fetal phase, during which one can only speak of a 'regio orbitalis,' is followed by a period in which we can speak of a primordial orbit; (4) the phase of the primordial orbit extends until after birth; (5) the surface area of all orbital walls increases more or less linearly; (6) the 'musculus orbitalis Mülleri' occupies a special place in the orbital wall; (7) the so-called 'regio craniolateralis' is the primordium, which, in the fully developed stage, is occupied by the thick intersection of the frontolateral and the horizontal part of the frontal bone; (8) in the frontal plane, the shape of the primordial orbit, as well as that of the fully developed orbit, is more or less round; (9) the prenatal development of an eye socket is a complex event, characterized by changes in composition, shape and size of the orbital wall; and (10) the orbit can only be denoted by the term "eye socket" when it is fully developed. At the

  5. Computational Modeling of Fluid Flow through a Fracture in Permeable Rock

    SciTech Connect

    Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H

    2010-01-01

    Laminar, single-phase, finite-volume solutions to the Navier–Stokes equations of fluid flow through a fracture within permeable media have been obtained. The fracture geometry was acquired from computed tomography scans of a fracture in Berea sandstone, capturing the small-scale roughness of these natural fluid conduits. First, the roughness of the two-dimensional fracture profiles was analyzed and shown to be similar to Brownian fractal structures. The permeability and tortuosity of each fracture profile was determined from simulations of fluid flow through these geometries with impermeable fracture walls. A surrounding permeable medium, assumed to obey Darcy’s Law with permeabilities from 0.2 to 2,000 millidarcies, was then included in the analysis. A series of simulations for flows in fractured permeable rocks was performed, and the results were used to develop a relationship between the flow rate and pressure loss for fractures in porous rocks. The resulting frictionfactor, which accounts for the fracture geometric properties, is similar to the cubic law; it has the potential to be of use in discrete fracture reservoir-scale simulations of fluid flow through highly fractured geologic formations with appreciable matrix permeability. The observed fluid flow from the surrounding permeable medium to the fracture was significant when the resistance within the fracture and the medium were of the same order. An increase in the volumetric flow rate within the fracture profile increased by more than 5% was observed for flows within high permeability-fractured porous media.

  6. Manned Venus Orbiting Mission

    NASA Technical Reports Server (NTRS)

    Willis, E. A., Jr.

    1967-01-01

    Manned orbiting stopover round trips to Venus are studied for departure dates between 1975 and 1986 over a range of trip times and stay times. The use of highly elliptic parking orbits at Venus leads to low initial weights in Earth orbit compared with circular orbits. For the elliptic parking orbit, the effect of constraints on the low altitude observation time on the initial weight is shown. The mission can be accomplished with the Apollo level of chemical propulsion, but advanced chemical or nuclear propulsion can give large weight reductions. The Venus orbiting mission weights than the corresponding Mars mission.

  7. Primary orbital melanoma associated with orbital melanocytosis.

    PubMed

    Rice, C D; Brown, H H

    1990-08-01

    We report a case of primary orbital melanoma in a 17-year-old girl. The patient presented with painless proptosis during the first trimester of pregnancy. Computed tomography demonstrated a well-circumscribed mass located infra-temporally in the right orbit. The tumor was bluish-black, grossly encapsulated, and associated with orbital blue nevi. Histologic examination of the mass revealed a pigmented spindle-cell neoplasm. On electron microscopy, the presence of premelanosomes and the absence of basal lamina supported the diagnosis of melanoma. Malignant transformation of a preexisting nevus is postulated since perineural foci of benign dendritic melanocytes were seen within the melanoma. There has been no recurrence or metastasis in a 2-year follow-up. Of 30 primary orbital melanomas reviewed, 12 (40%) were associated with periorbital pigmentary disorders, such as oculodermal melanocytosis, blue nevus, and ocular melanocytosis. Our case is unique since the pigmentary lesions were limited to the orbital tissues.

  8. On material fracture criteria

    NASA Astrophysics Data System (ADS)

    Kremnev, L. S.

    2017-01-01

    Based on the nonlinear mechanics of material fracture, a model of the fracture of materials with actual (discrete) structures has been constructed. The model is supported by proofs that crack resistance K 1 c and fracture toughness G 1 c obtained from the energy conservation law without using the assumptions adopted in the linear material fracture mechanics serve as the force and energy criteria in the nonlinear fracture mechanics. It has been shown that energy criterion G 1 c in the nonlinear mechanics is much greater than G 1 c in the linear fracture mechanics.

  9. A Single-Center Review of Radiologically Diagnosed Maxillofacial Fractures: Etiology and Distribution.

    PubMed

    Halsey, Jordan N; Hoppe, Ian C; Granick, Mark S; Lee, Edward S

    2017-03-01

    The etiology of fractures of the maxillofacial skeleton varies among studies, with motor vehicle accidents and assaults oftentimes the most common. The number of males outnumbers females throughout most studies. Fractures of the zygoma, orbit, and mandible are usually cited as most common fracture types. This study examines a single center's experience with regards to etiology and distribution of fractures. A retrospective review of all radiologically confirmed facial fractures in a level 1 trauma center in an urban environment was performed for the years 2000 to 2012. Patient demographics, etiology of injury, and location of fractures were collected. During this time period, 2,998 patients were identified as having sustained a fracture of the facial skeleton. The average age was 36.9 years, with a strong male predominance (81.5%). The most common etiologies of injury were assault (44.9%) and motor vehicle accidents (14.9%). Throughout the study period, the number of fractures as a result of assault remained relatively constant, whereas the number as a result of motor vehicle accidents decreased slightly. The most common fracture observed was of the orbit, followed by mandible, nasal bones, zygoma, and frontal sinus. Patients sustaining a fracture as a result of assault were more likely to have a mandible fracture. Patients in motor vehicle accidents were more likely to suffer fractures of the maxilla, orbit, and frontal sinus. Mandible fractures are more common in cases of assault. Motor vehicle accidents convey a large force, which, when directed at the craniofacial skeleton, can cause a variety of fracture patterns. The decreasing number of fractures as a result of motor vehicle accidents may represent improved safety devices such as airbags.

  10. Rotary press utilizing a flexible die wall.

    PubMed

    Amidon, G E; Smith, D P; Hiestand, E N

    1981-06-01

    A die with a flexible wall was constructed and evaluated on a specially modified instrumented rotary tablet press. The design permits an inward deflection of the die wall by a side punch, which rolls past a side compression roll during compression-decompression. The side compression roll is instrumented to monitor the applied side compression roll forces. On decompression, return of the die wall to its original position permits release of residual die wall pressure. The decreased residual die wall pressure can decrease fracture and capping of tablets for problem formulations. The performance was tested on three experimental formulations. For these formulations, tablets made in a conventional die exhibited severe capping problems. However, most tablets compressed in the special die were superior. With proper adjustment of punch and die wall compression forces, excellent tablets could be manufactured. The merits of the special die and modified tablet machine are substantiated, although this initial design did not provide adequate die wall pressure for all formulations. Further engineering efforts could result in practical production equipment.

  11. OEX - Use of the Shuttle Orbiter as a research vehicle

    NASA Technical Reports Server (NTRS)

    Jones, J. J.

    1981-01-01

    The Orbiter Experiments Program to provide research instrumentation on the Shuttle Orbiter is discussed. Flight aerodynamic problems such as ground-based data limitations, rarefied flow effects, body flap and control surface effectiveness, and windward surface heat transfer are reviewed. Experiments currently under development are described, including experiments on tile gaps and wall catalytic effects which provide the opportunity to obtain data not available in ground facilities and apply the results to improvements in the Orbiter's thermal protection system. Such experiments combined with other instrumentation on the Orbiter should provide benchmark flight data which can make a significant impact on the design of future space transportation systems.

  12. Permeability of displaced fractures

    NASA Astrophysics Data System (ADS)

    Kluge, Christian; Milsch, Harald; Blöcher, Guido

    2017-04-01

    Flow along fractures or in fissured systems becomes increasingly important in the context of Enhanced Geothermal Systems (EGS), shale gas recovery or nuclear waste deposit. Commonly, the permeability of fractures is approximated using the Hagen-Poiseuille solution of Navier Stokes equation. Furthermore, the flow in fractures is assumed to be laminar flow between two parallel plates and the cubic law for calculating the velocity field is applied. It is a well-known fact, that fracture flow is strongly influenced by the fracture surface roughness and the shear displacement along the fracture plane. Therefore, a numerical approach was developed which calculates the flow pattern within a fracture-matrix system. The flow in the fracture is described by a free fluid flow and the flow in the matrix is assumed to be laminar and therefore validates Darcy's law. The presented approach can be applied for artificially generated fractures or real fractures measured by surface scanning. Artificial fracture surfaces are generated using the power spectral density of the surface height random process with a spectral exponent to define roughness. For calculating the permeability of such fracture-matrix systems the mean fracture aperture, the shear displacement and the surface roughness are considered by use of a 3D numerical simulator. By use of this approach correlation between shear displacement and mean aperture, shear displacement and permeability, as well as surface roughness and permeability can be obtained. Furthermore, the intrinsic measured permeability presents a combination of matrix and fracture permeability. The presented approach allows the separation and quantification of the absolute magnitudes of the matrix and the fracture permeability and the permeability of displaced fractures can be calculated. The numerical approach which is a 3D numerical simulation of the fracture-matrix system can be applied for artificial as well as real systems.

  13. How Vein Sealing Boosts Fracture Opening

    NASA Astrophysics Data System (ADS)

    Nüchter, Jens-Alexander

    2015-04-01

    Veins from from cracks. As such, a stage of brittle failure and fracturing is to be set apart from a stage of opening and sealing. The process of fracture opening requires distortion of the host rocks to create space for the evolving vein. To keep a crack arrested and, at the same time, to widen or stabilize the cavity, the stress intensity factor K_I=(P-S3)(πa) must remain below the fracture toughness K_IC of the host rock, and P-S3 >0 (P and S3 denote pore fluid pressure and absolute minimum principal stress, respectively and 'a' refers to the half-length of the fracture). For purely elastic distortion of the host rocks, maximum aperture W0=K_IC (1-ν^2)/(E(π/8)^1/2))(2a)^1/2 depends on on K_IC, Poisson's ratio ν, and Young's modulus E of the host rocks. Owing to the low values for rock K_IC typically ranging between 0.1 and 1 MPa m^1/2, veins formed by purely elastic distortion of the host rocks are restricted to high aspect ratios 2a/W. In metamorphic rocks, veins with low aspect ratios are common; inelastic deformation and viscous creep in the host rocks must have contributed to final vein shapes. In the present study, I use finite element models to simulate fracture opening and cavity formation supported by viscous creep distributed in the host rock. Simulations are carried out on 2D plate models containing elliptical fractures. The walls of the fractures are coated by thin layers simulating incipient sealing; a residual cavity prevails in the centre of the model veins. Constant displacement is applied to the plate boundaries oriented normal to the cracks. I run a series of models with various viscosity contrasts between the rocks and the sealing. The results of these models indicate the following. (1) Fracture opening is most effective when the viscosity of the sealing ηs exceeds the viscosity of the host rocks ηr (2) The rate of fracture opening increases with increasing values for ηs/ηr . (3) An increase in the thickness of the sealing layer causes

  14. Lunar orbiting prospector

    NASA Technical Reports Server (NTRS)

    1988-01-01

    One of the prime reasons for establishing a manned lunar presence is the possibility of using the potential lunar resources. The Lunar Orbital Prospector (LOP) is a lunar orbiting platform whose mission is to prospect and explore the Moon from orbit in support of early lunar colonization and exploitation efforts. The LOP mission is divided into three primary phases: transport from Earth to low lunar orbit (LLO), operation in lunar orbit, and platform servicing in lunar orbit. The platform alters its orbit to obtain the desired surface viewing, and the orbit can be changed periodically as needed. After completion of the inital remote sensing mission, more ambitious and/or complicated prospecting and exploration missions can be contemplated. A refueled propulsion module, updated instruments, or additional remote sensing packages can be flown up from the lunar base to the platform.

  15. Prolonged pain and disability are common after rib fractures.

    PubMed

    Fabricant, Loic; Ham, Bruce; Mullins, Richard; Mayberry, John

    2013-05-01

    The contribution of rib fractures to prolonged pain and disability may be underappreciated and undertreated. Clinicians are traditionally taught that the pain and disability of rib fractures resolves in 6 to 8 weeks. This study was a prospective observation of 203 patients with rib fractures at a level 1 trauma center. Chest wall pain was evaluated by the McGill Pain Questionnaire (MPQ) pain rating index (PRI) and present pain intensity (PPI). Prolonged pain was defined as a PRI of 8 or more at 2 months after injury. Prolonged disability was defined as a decrease in 1 or more levels of work or functional status at 2 months after injury. Predictors of prolonged pain and disability were determined by multivariate analysis. One hundred forty-five male patients and 58 female patients with a mean injury severity score (ISS) of 20 (range, 1 to 59) had a mean of 5.4 rib fractures (range, 1 to 29). Forty-four (22%) patients had bilateral fractures, 15 (7%) had flail chest, and 92 (45%) had associated injury. One hundred eighty-seven patients were followed 2 months or more. One hundred ten (59%) patients had prolonged chest wall pain and 142 (76%) had prolonged disability. Among 111 patients with isolated rib fractures, 67 (64%) had prolonged chest wall pain and 69 (66%) had prolonged disability. MPQ PPI was predictive of prolonged pain (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.4 to 2.5), and prolonged disability (OR, 2.2; 95% CI, 1.5 to 3.4). The presence of significant associated injuries was predictive of prolonged disability (OR, 5.9; 95% CI, 1.4 to 29). Prolonged chest wall pain is common, and the contribution of rib fractures to disability is greater than traditionally expected. Further investigation into more effective therapies that prevent prolonged pain and disability after rib fractures is needed. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Colloid Transport and Retention in Fractured Media

    SciTech Connect

    McCarthy, J.F.

    2001-02-01

    The goal of this project was to identify the chemical and physical factors that control the transport of colloids in fractured materials, and develop a generalized capability to predict colloid attachment and detachment based on hydraulic factors (head, flow rate), physical processes and structure (fracture aperture, matrix porosity), and chemical properties (surface properties of colloids, solution chemistry, and mineralogy of fracture surfaces). Both aqueous chemistry and physical structure of geologic formations influenced transport. Results of studies at all spatial scales reached consensus on the importance of several key controlling variables: (1) colloid retention is dominated by chemical conditions favoring colloid-wall interactions; (2) even in the presence of conditions favorable to colloid collection, deposited colloids are remobilized over long times and this process contributes substantially to the overall extent of transport; (3) diffusive exchange between water-conducting fractures and finer fractures and pores acts to ''buffer'' the effects of the major fracture network structure, and reduces predictive uncertainties. Predictive tools were developed that account for fundamental mechanisms of colloid dynamics in fracture geometry, and linked to larger-scale processes in networks of fractures. The results of our study highlight the key role of physical and hydrologic factors, and processes of colloid remobilization that are potentially of even greater importance to colloid transport in the vadose zone than in saturated conditions. We propose that this work be extended to focus on understanding vadose zone transport processes so that they can eventually be linked to the understanding and tools developed in our previous project on transport in saturated groundwater systems.

  17. Channel Wall Landslides

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The multiple landslides in this VIS image occur along a steep channel wall. Note the large impact crater in the context image. The formation of the crater may have initially weakened that area of the surface prior to channel formation.

    Image information: VIS instrument. Latitude -2.7, Longitude 324.8 East (35.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  18. Channel Wall Landslides

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The multiple landslides in this VIS image occur along a steep channel wall. Note the large impact crater in the context image. The formation of the crater may have initially weakened that area of the surface prior to channel formation.

    Image information: VIS instrument. Latitude -2.7, Longitude 324.8 East (35.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. Sprains, Strains and Fractures

    MedlinePlus

    ... Young Physicians Annual Scientific Meeting Webinars Careers in Podiatry APMA 2040 Student Profiles CPME REdRC Manage Your ... and fractures. Many fractures and sprains occur during sports. Football players are particularly vulnerable to foot and ...

  20. Infant skull fracture (image)

    MedlinePlus

    Skull fractures may occur with head injuries. Although the skull is both tough and resilient and provides excellent ... or blow can result in fracture of the skull and may be accompanied by injury to the ...

  1. Everted skull fracture.

    PubMed

    Balasubramaniam, Srikant; Tyagi, Devendra K; Savant, Hemant V

    2011-11-01

    Skull bone fractures are common in trauma. They are usually linear undisplaced or depressed; however, a distinct possibility of elevated fracture remains. We describe an entity of everted fracture skull in which the fracture segment is totally everted. The nature of trauma, management, and complications of this unique case are discussed. A 21-year-old woman involved in a railway accident presented to us with a primary dressing on her wound. Investigations revealed an everted fracture skull. She underwent surgery with good results. We would like to add everted fracture skull to the nomenclature describing skull fractures in addition to elevated compound fracture skull as a new entity. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Metatarsal stress fractures - aftercare

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000553.htm Metatarsal stress fractures - aftercare To use the sharing features on ... that connect your ankle to your toes. A stress fracture is a break in the bone that ...

  3. Fractures in anisotropic media

    NASA Astrophysics Data System (ADS)

    Shao, Siyi

    Rocks may be composed of layers and contain fracture sets that cause the hydraulic, mechanical and seismic properties of a rock to be anisotropic. Coexisting fractures and layers in rock give rise to competing mechanisms of anisotropy. For example: (1) at low fracture stiffness, apparent shear-wave anisotropy induced by matrix layering can be masked or enhanced by the presence of a fracture, depending on the fracture orientation with respect to layering, and (2) compressional-wave guided modes generated by parallel fractures can also mask the presence of matrix layerings for particular fracture orientations and fracture specific stiffness. This report focuses on two anisotropic sources that are widely encountered in rock engineering: fractures (mechanical discontinuity) and matrix layering (impedance discontinuity), by investigating: (1) matrix property characterization, i.e., to determine elastic constants in anisotropic solids, (2) interface wave behavior in single-fractured anisotropic media, (3) compressional wave guided modes in parallel-fractured anisotropic media (single fracture orientation) and (4) the elastic response of orthogonal fracture networks. Elastic constants of a medium are required to understand and quantify wave propagation in anisotropic media but are affected by fractures and matrix properties. Experimental observations and analytical analysis demonstrate that behaviors of both fracture interface waves and compressional-wave guided modes for fractures in anisotropic media, are affected by fracture specific stiffness (controlled by external stresses), signal frequency and relative orientation between layerings in the matrix and fractures. A fractured layered medium exhibits: (1) fracture-dominated anisotropy when the fractures are weakly coupled; (2) isotropic behavior when fractures delay waves that are usually fast in a layered medium; and (3) matrix-dominated anisotropy when the fractures are closed and no longer delay the signal. The

  4. Forearm Fractures in Children

    MedlinePlus

    .org Forearm Fractures in Children The forearm is the part of the arm between the wrist and the elbow. It is ... two bones: the radius and the ulna. Forearm fractures are common in childhood, accounting for more than ...

  5. Nasal fracture (image)

    MedlinePlus

    A nasal fracture is a break in the bone over the ridge of the nose. It usually results from a blunt ... and is one of the most common facial fracture. Symptoms of a broken nose include pain, blood ...

  6. Bone fracture repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100077.htm Bone fracture repair - series—Indications To use the sharing features ... Go to slide 4 out of 4 Overview Fractures of the bones are classified in a number ...

  7. Femur fracture repair - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000166.htm Femur fracture repair - discharge To use the sharing features on this page, please enable JavaScript. You had a fracture (break) in the femur in your leg. It ...

  8. Fractures and Channels

    NASA Image and Video Library

    2013-01-22

    This image from NASA 2001 Mars Odyssey spacecraft of the Claritas Fossae region illustrates how fractures affect other features. In this instance, the fractures control the path of several channels from upper right towards lower left.

  9. Periprosthetic acetabular fractures.

    PubMed

    Benazzo, Francesco; Formagnana, Mario; Bargagliotti, Marco; Perticarini, Loris

    2015-10-01

    The aim of this article is to propose a diagnostic and therapeutic algorithm for the acetabular periprosthetic fractures. This article explores the current literature on the epidemiology, causes and classification of periprosthetic acetabular fractures. Integrating data with the experience of the authors, it offers a guide to diagnosis and possible therapeutic strategies. Intra-operative fractures can occur during rasping, reaming or implant impaction, and they must be treated immediately if the component(s) is (are) unstable. Post-operative fractures can be due to major trauma (acute fractures) or minor forces in bone osteolysis; it is possible to plan reconstruction and fixation according to fracture characteristics. Treatment choice depends upon fracture site and implant stability. Periprosthetic acetabular fractures are uncommon complications that can occur intra-operatively or post-operatively, and a reconstructive surgeon must be able to manage the procedure. Accurate planning and reconstruction implant are necessary to achieve good cup stability.

  10. Five Equivalent d Orbitals

    ERIC Educational Resources Information Center

    Pauling, Linus; McClure, Vance

    1970-01-01

    Amplifies and clarifies a previous paper on pyramidal d orbitals. Discusses two sets of pyramid d orbitals with respect to their maximum bond strength and their symmetry. Authors described the oblate and prolate pentagonal antiprisms arising from the two sets of five equivalent d orbitals. (RR)

  11. Introducing Earth's Orbital Eccentricity

    ERIC Educational Resources Information Center

    Oostra, Benjamin

    2015-01-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…

  12. Introducing Earth's Orbital Eccentricity

    ERIC Educational Resources Information Center

    Oostra, Benjamin

    2015-01-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…

  13. SEASAT B orbit synthesis

    NASA Technical Reports Server (NTRS)

    Rea, F. G.; Warmke, J. M.

    1976-01-01

    Addition were made to Battelle's Interactive Graphics Orbit Selection (IGOS) program; IGOS was exercised via telephone lines from JPL, and candidate SEASAT orbits were analyzed by Battelle. The additions to the program enable clear understanding of the implications of a specific orbit to the diverse desires of the SEASAT user community.

  14. Periprosthetic fracture of the acetabulum after total hip arthroplasty.

    PubMed

    Peterson, C A; Lewallen, D G

    1996-08-01

    Eleven patients who had sustained a periprosthetic fracture of the acetabulum at a mean of 6.2 years (range, one month to thirteen years) after a total hip arthroplasty were managed at our institution between 1985 and 1991. Five patients had a fracture of the medial wall; three, a fracture of the posterior column; two, a transverse fracture; and one, a fracture of the anterior column. Six fractures were displaced by two millimeters or more. Eight fractures were caused by blunt trauma or a fall, and three occurred spontaneously. A fracture was classified as type 1 if the acetabular component was clinically and radiographically stable (eight patients) and as type 2 if the component was unstable (three patients). One patient, who had a displaced type-2 fracture of the posterior column, died of an associated intrapelvic vascular injury. The other two patients who had a type-2 fracture were managed with revision of the acetabular component without supplemental plate fixation, immediately after the diagnosis of the fracture. The eight patients who had a type-1 fracture initially were managed with limitation of weight-bearing or modification of activity; in six of these patients, the fracture united without additional treatment. The ten surviving patients were followed for a mean of sixty-two months after the fracture. Eight of these patients-including four in whom a type-1 fracture had united after non-operative treatment-had a revision of the acetabular component because of pain, loosening, or non-union by the time of the most recent follow-up. Two patients (one of whom had a type-1 fracture and the other, a type-2 fracture) had multiple revisions of the acetabular component; both had supplemental internal fixation with a plate. All ten patients ultimately had a stable, functioning prosthesis. We conclude that periprosthetic acetabular fractures are associated with a poor prognosis with regard to the survival of the acetabular component but that it is possible to

  15. Land-Surface Subsidence and Open Bedrock Fractures in the Tully Valley, Onondaga County, New York

    USGS Publications Warehouse

    Hackett, William R.; Gleason, Gayle C.; Kappel, William M.

    2009-01-01

    Open bedrock fractures were mapped in and near two brine field areas in Tully Valley, New York. More than 400 open fractures and closed joints were mapped for dimension, orientation, and distribution along the east and west valley walls adjacent to two former brine fields. The bedrock fractures are as much as 2 feet wide and over 50 feet deep, while linear depressions in the soil, which are 3 to 10 feet wide and 3 to 6 feet deep, indicate the presence of open bedrock fractures below the soil. The fractures are probably the result of solution mining of halite deposits about 1,200 feet below the land surface.

  16. Dry fracture method for simultaneous measurement of in-situ stress state and material properties

    SciTech Connect

    Serata, S.; Oka, S.; Kikuchi, S.

    1996-04-01

    Based on the dry fracture principle, a computerized borehole probe has been developed to measure stress state and material properties, simultaneously. The probe is designed to obtain a series of measurements in a continuing sequence along a borehole length, without any interruptive measures, such as resetting packers, taking indentation of borehole wall, overcoming, etc. The new dry fracture probe for the single fracture method is designed to overcome the difficulties posed by its ancestor which was based on the double fracture method. The accuracy of the single fracture method is confirmed by a close agreement with the theory, FE modeling and laboratory testing.

  17. 3D characterization of the fracture network in a deformed chalk reservoir analogue: The Lagerdorf case

    SciTech Connect

    Koestler, A.G.; Reksten, K.

    1994-12-31

    Quantitative descriptions of the 3D fracture networks in terms of connectivity, fracture types, fracture surface roughness and flow characteristics are necessary for reservoir evaluation, management, and enhanced oil recovery programs of fractured reservoirs. For a period of 2 years, a research project focused on an analogue to fractured chalk reservoirs excellently exposed near Laegerdorf, NW Germany. Upper Cretaceous chalk has been uplifted and deformed by an underlying salt diapir, and is now exploited for the cement industry. In the production wall of a quarry, the fracture network of the deformed chalk was characterized and mapped at different scales. The wall was scraped off as chalk exploitation proceeded, continuously revealing new sections through the faulted and fractured chalk body. A 230 m long part of the 35m high production wall was investigated during its recess of 25m. The large amount of fracture data were analyzed with respect to parameters such as fracture density distribution, orientation- and length distribution, and in terms of the representativity of data sets collected from restricted rock volumes. This 3D description and analysis of a fracture network revealed quantitative generic parameters of importance for modeling chalk reservoirs with less data and lower data quality.

  18. [Potentials of 3D-modeling in reconstructive orbital surgery].

    PubMed

    Butsan, S B; Khokhlachev, S B; Ĭigitaliev, Sh N; Zaiakin, Ia A

    2012-01-01

    A technique of bone reconstructive surgery of orbitofrontonasomalar region using 3D-modeling based on multispiral computer tomography data is presented. The efficacy of intraoperative templates created using 3D-modeling was showed for harvesting and modeling of bone calvarial autografts. The steps of reconstructive procedure are explained in details for repair of medial and inferior orbital fractures.

  19. Impact of normal stress on multiphase flow through rough fractures

    NASA Astrophysics Data System (ADS)

    Alves da Silva Junior, J.; Kang, P. K.; Yang, Z.; Cueto-Felgueroso, L.; Juanes, R.

    2015-12-01

    Fluid flow and transport through geologic fractures plays a key role in several areas such as groundwater hydrology, geothermal energy, oil and gas production, CO2 sequestration and nuclear waste disposal. High-permeability zones associated with fracture corridors often serve as fast fluid conduits for both single and multiphase flow in otherwise low-permeability media. When multiphase flow occurs, the presence of one phase interferes with the flow of the other phase, resulting in complex displacement patterns through the fracture, and macroscopic descriptors (such as fracture-scale capillary pressure and relative permeability) that depend on the phase concentration of both phases. Here, we investigate the impact of normal stress on single and multiphase flow through rough-walled fractures: (1) we generate synthetic aperture fields that honor the fractal roughness structure observed in real fractures; (2) we model the effect of normal stress on the fracture aperture geometry by solving the contact problem between fracture walls; and (3) we use invasion percolation with trapping to model immiscible fluid displacement and then compute relative permeability numerically for each stress scenario. Our results indicate that normal stress increases the amount of contact area in the fracture wall, which results in an increase of the tortuosity of the available path for fluid displacement. Increasing normal stress results in low relative permeability for the wetting phase due to a decrease of the available path for fluid flow, and therefore a small amount of non-wetting fluid has a large impact on the flow of the wetting fluid. We find that the relative permeability of the non-wetting fluid shows less variation with stress than the wetting fluid, and that both fluids exhibit strong phase interference at intermediate saturations. Finally, we show early results from our experimental work currently underway to validate the modeling results.

  20. [Epidemiological view of fracture risk].

    PubMed

    Fujiwara, Saeko

    2010-09-01

    Incidence of hip fracture increases exponentially with age. Women had two times higher hip fracture incidence than men. Major risk factors for the hip fracture are age, sex, bone mineral density, and previous fracture and others, but each risk factor contributes differently to development of the fracture by sites. Factors related to fall are important role in developing hip fracture.

  1. Wall surveyor project report

    SciTech Connect

    Mullenhoff, D.J.; Johnston, B.C.; Azevedo, S.G.

    1996-02-22

    A report is made on the demonstration of a first-generation Wall Surveyor that is capable of surveying the interior and thickness of a stone, brick, or cement wall. LLNL`s Micropower Impulse Radar is used, based on emitting and detecting very low amplitude and short microwave impulses (MIR rangefinder). Six test walls were used. While the demonstrator MIR Wall Surveyor is not fieldable yet, it has successfully scanned the test walls and produced real-time images identifying the walls. It is planned to optimize and package the evaluation wall surveyor into a hand held unit.

  2. Fracture Education in Engineering.

    ERIC Educational Resources Information Center

    Sidey, D.; And Others

    Fracture mechanics is a multidisciplinary topic which is being introduced to undergraduate engineering students in such courses as materials engineering. At a recent Conference on Fracture held at the University of Waterloo, a session was devoted to fracture education. Some of the ideas presented at that session are included and discussed here.…

  3. [Osteoporosis and Colles' fracture].

    PubMed

    Hindsø, K; Lauritzen, J B

    2001-10-01

    We describe the connection between osteoporosis and Colles' fractures of the distal radius from an epidemiological and aetiological point of view. In addition, the value of these fractures as markers of osteoporosis and future risk of fracture is assessed. Several studies have clearly shown an epidemiological association between osteoporosis and fractures of the distal radius, with the association strongest for women up to 65 years of age and for osteoporosis located in the forearm. The association weakens for other locations and for older women. Osteoporosis may have some aetiologic significance for the development of Colles' fractures, but several extraskeletal factors are of equal or further importance. The occurrence of a Colles' fracture in the first 10-15 years after the postmenopause indicates an increased relative risk of sustaining another fracture in the future. However the relative risk approaches one after a few years and, because of the comparatively low absolute risk in this age-group, Colles' fracture as a risk factor contributes little to an assessment of the lifetime fracture risk. In a few longitudinal studies, Colles' fractures could not predict the long-term risk of osteoporosis. The presence of a Colles' fracture should lead to considerations concerning the skeletal and extraskeletal causes of the fracture for the purpose of initiating preventive and therapeutic measures.

  4. Elbow fractures and dislocations.

    PubMed

    Little, Kevin J

    2014-07-01

    Elbow fractures are common in pediatric patients. Most injuries to the pediatric elbow are stable and require simple immobilization; however, more severe fractures can occur, often requiring operative stabilization and/or close monitoring. This article highlights the common fractures and dislocations about the pediatric elbow and discusses the history, evaluation, and treatment options for specific injuries.

  5. Penetrating injury of orbital roof and brain sparing the eye ball in a pediatric patient: A rare occurrence.

    PubMed

    Kumar, Vikul; Singh, Atul Kumar; Bhaikhel, Kulwant Singh

    2016-01-01

    Blowout fractures are a common occurrence in traumatic brain injury patients. In pediatric age group, orbital floor fracture is a common occurrence. We report a case of 2-year-old male admitted to trauma center, with penetrating injury to the left eye by the clutch of motorbike which fell on the child. Noncontrast computed tomography scan revealed fracture of the roof of left orbit with left frontal contusion sparing the left eyeball. There was also the continuous leak of brain matter from the left eye which suggested tear of dura mater. Urgent left frontal craniotomy was done with the evacuation of contusion, reconstruction of orbital roof, and duroplasty under general anesthesia.

  6. Pelvic, acetabular and hip fractures: What the surgeon should expect from the ra