The importance of accurate, early bony reconstruction in orbital injuries with globe loss.
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ABSTRACT:
SUBMITTER: Birgfeld C
PROVIDER: S-EPMC3193312 | biostudies-other | 2011 Sep
REPOSITORIES: biostudies-other
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Project description:PurposeComplex bony orbital defects are reconstructively challenging due to loss of intraoperative anatomical landmarks and adjacent support. Presized and precontoured porous polyethylene-titanium implants (Medpor Titan 3D Orbital Floor Implant) are designed to reestablish normal orbital floor and medial wall anatomy and are modeled after anatomically averaged orbits. This is the first study to report clinical outcomes with this implant.MethodsThis retrospective case series reviewed clinical data and outcomes for patients undergoing orbital reconstruction with a presized and precontoured porous polyethylene-titanium orbital implant from January 2016 to June 2018.ResultsA total of 34 orbits of 33 patients were identified (mean age: 43 ± 16 years, 70% men). Most bony defects were a result of trauma and included large orbital floor deformities (100%), medial wall defects (74%), disrupted inferomedial struts (68%), and broken posterior ledges (82%). Symptomatic diplopia (73%) and enophthalmos (89%, mean: 3.7 ± 2.1 mm) were common preoperatively. Many cases were revisions (44%). Mean follow up was 7.8 ± 6.7 months. All patients had improved globe positioning, enophthalmos, and hypoglobus. Seven patients had persistent postoperative diplopia: 6 responded to prism therapy and 1 required strabismus surgery. One patient required retrobulbar hematoma drainage and 1 patient required implant explantation due to chronic infection.ConclusionsCommercially available presized and precon toured porous polyethylene-titanium implants are useful for complex orbital bony defects and can achieve functional improve ments in diplopia, enophthalmos, and extraocular motility with a low incidence of postoperative complications or revisional surgery.
| S-EPMC7982351 | biostudies-literature
Project description:BackgroundAccurate measurement and reconstruction of orbital soft tissue is important to diagnosis and treatment of orbital diseases. This study applied an interactive graph cut method to orbital soft tissue precise segmentation and calculation in computerized tomography (CT) images, and to estimate its application in orbital reconstruction.MethodsThe interactive graph cut method was introduced to segment extraocular muscle and intraorbital fat in CT images. Intra- and inter-observer variability of tissue volume measured by graph cut segmentation was validated. Accuracy and reliability of the method was accessed by comparing with manual delineation and commercial medical image software. Intraorbital structure of 10 patients after enucleation surgery was reconstructed based on graph cut segmentation and soft tissue volume were compared within two different surgical techniques.ResultsBoth muscle and fat tissue segmentation results of graph cut method showed good consistency with ground truth in phantom data. There were no significant differences in muscle calculations between observers or segmental methods (p > 0.05). Graph cut results of fat tissue had coincidental variable trend with ground truth which could identify 0.1cm3 variation. The mean performance time of graph cut segmentation was significantly shorter than manual delineation and commercial software (p < 0.001). Jaccard similarity and Dice coefficient of graph cut method were 0.767 ± 0.045 and 0.836 ± 0.032 for human normal extraocular muscle segmentation. The measurements of fat tissue were significantly better in graph cut than those in commercial software (p < 0.05). Orbital soft tissue volume was decreased in post-enucleation orbit than that in normal orbit (p < 0.05).ConclusionThe graph cut method was validated to have good accuracy, reliability and efficiency in orbit soft tissue segmentation. It could discern minor volume changes of soft tissue. The interactive segmenting technique would be a valuable tool for dynamic analysis and prediction of therapeutic effect and orbital reconstruction.
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Project description:BackgroundOrbital exenteration, the removal of the entire globe, eyelids, and orbital content, is indicated in extensive neoplastic disease involving the orbital region. Although a functional reconstruction of orbital exenteration defects is mandatory, aesthetic concerns need to be considered. Facial disfigurement following reconstructive surgery often leads to great discomfort and social retirement, which can limit social interaction. The aim of this study was to explore how the society perceives the aspect of patients who underwent orbital exenteration and subsequent reconstruction, comparing two different types of reconstruction: standard anterolateral thigh (ALT) or "sandwich" fascial ALT (SALT) free flap.MethodsAn online survey was created based on four questions regarding the perception of reconstruction (discomfort at looking at that patient, perception of unhealthiness, hypothesis of social life impairment, etc); five possible answers were provided, ranging from "completely" to "not at all." The survey was administered to the general population and to medical students.ResultsIn total, 255 people participated to the survey (130 medical students and 125 people of the general population); a total of 245 surveys were considered eligible (10 were incomplete and then discharged). Statistical significance was found (P < 0.001) regarding the better overall appearance of the SALT group over the ALT one.ConclusionsAfter analysis, the surgical outcome after SALT reconstruction has been found to be less disruptive in both groups, due to a reduced scar burden and a more pleasant orbital pocket. Our results encourage more research in the field of postexenteration reconstruction to achieve more aesthetic and social acceptability.
| S-EPMC8547912 | biostudies-literature
Project description:A 61-year-old Chinese man presented to the emergency department with a 1-day history of painful swelling of the right eyelid with loss of vision. He had been treated earlier for an isolated pathological fracture of the T7 vertebra from plasmacytoma. Computed tomography was suggestive of superior orbital hematoma with bony erosion of the inner and outer tables of an isolated frontal cell, and urgent drainage of the hematoma resulted in relief of the pain and improvement of the vision. A formal orbitotomy was performed to evacuate the hematoma, followed by combined endoscopic sinus surgery and external anterior frontal table trephine to connect the isolated cell to the frontal sinus. The histology did not show evidence of myeloma, and the orbital hematoma was probably a result of an acute hemorrhage into the mucocele of an isolated cell in the frontal bone. However, in patients with a history of multiple myeloma, it is important to consider lytic bony involvement as the cause of an orbital hemorrhage.
| S-EPMC3314254 | biostudies-other
Project description:BackgroundBony destructive injury of the calcaneus (BDIC) represents one of the most severe comminuted fractures of the calcaneus in which soft tissue coverage remains intact. The features of this injury include a collapsed articular surface, significant widening, severe loss of height and an unrecognisable outline of the calcaneus. This study aims to present the long-term outcomes of BDIC treated in a minimally invasive fashion followed by supervised early exercise.MethodsTwelve patients with unilateral BDICs were treated at our institution. The main surgical procedures included percutaneous traction and leverage reduction and internal compression fixation with anatomic plates and compression bolts. Early functional exercise was encouraged to mould the subtalar joint. The height, length and width of the calcaneus; Böhler's and Gissane's angles; reduction of the articular surfaces; and functional recovery of the affected feet were assessed.ResultsThe height, length and width of the calcaneus were substantially restored. The mean Böhler's and Gissane's angles of the affected calcaneus were 24.5 and 122.8 degrees, respectively. Five patients regained anatomical or nearly anatomical reduction of their posterior facets. Residual articular displacement of more than 3 mm was noted in three patients. Patients were followed for a mean of 93.9 months. The mean American Orthopaedic Foot and Ankle Society score was 83.8. Nine patients showed excellent or good results. Radiographic evidence of post-traumatic subtalar arthritis was observed in four cases. However, no subtalar arthrodesis was required.ConclusionsBDICs can be treated effectively with percutaneous reduction and internal compression fixation followed by early active exercise. This protocol resulted in satisfactory radiological and functional outcomes.
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Project description:HOMO and LUMO energies are critical molecular properties that typically require high accuracy computations for practical applicability. Until now, a comprehensive dataset containing sufficiently accurate HOMO and LUMO energies has been unavailable. In this study, we introduce a new dataset of HOMO/LUMO energies for QM9 compounds, calculated using the GW method. The GW method offers adequate HOMO/LUMO prediction accuracy for diverse applications, exhibiting mean unsigned errors of 100 meV in the GW100 benchmark dataset. This database may serve as a benchmark of HOMO/LUMO prediction, delta-learning, and transfer learning, particularly for larger molecules where GW is the most accurate but still numerically feasible method. We anticipate that this dataset will enable the development of more accurate machine learning models for predicting molecular properties.
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Project description:A promising route to tailoring the electronic properties of quantum materials and devices rests on the idea of orbital engineering in multilayered oxide heterostructures. Here we show that the interplay of interlayer charge imbalance and ligand distortions provides a knob for tuning the sequence of electronic levels even in intrinsically stacked oxides. We resolve in this regard the d-level structure of layered Sr2IrO4 by electron spin resonance. While canonical ligand-field theory predicts g||-factors less than 2 for positive tetragonal distortions as present in Sr2IrO4, the experiment indicates g|| is greater than 2. This implies that the iridium d levels are inverted with respect to their normal ordering. State-of-the-art electronic-structure calculations confirm the level switching in Sr2IrO4, whereas we find them in Ba2IrO4 to be instead normally ordered. Given the nonpolar character of the metal-oxygen layers, our findings highlight the tetravalent transition-metal 214 oxides as ideal platforms to explore d-orbital reconstruction in the context of oxide electronics.
| S-EPMC4491190 | biostudies-literature
Project description:We demonstrate the microscopic role of oxygen vacancies spatially confined within nanometer inter-spacing (about 1 nm) in BiFeO3, using resonant soft X-ray scattering techniques and soft X-ray spectroscopy measurements. Such vacancy confinements and total number of vacancy are controlled by substitution of Ca(2+) for Bi(3+) cation. We found that by increasing the substitution, the in-plane orbital bands of Fe(3+) cations are reconstructed without any redox reaction. It leads to a reduction of the hopping between Fe atoms, forming a localized valence band, in particular Fe 3d-electronic structure, around the Fermi level. This band localization causes to decrease the conductivity of the doped BiFeO3 system.
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Project description:Purpose:To assess the clinical efficacy of custom made PEEK patient-specific implants in treatment of orbital wall defects. Methods:Forty-five patients with unilateral post-traumatic orbital wall defects were enrolled in the study. They underwent subsequent reconstructive procedures using PEEK patient-specific implants (PSI) or pre-bent titanium plates. All the patients were examined with the standardized algorithm, including local status examination, vision assessment and computer tomography (CT) with measurements of the orbital volume. A comparative analysis of the treatment outcomes in two groups of patients (pre-bent plates/PSI) was performed. Results:The study findings show an absence of any postoperative infection, inflamation or decreased visual acuity in either group. In PSI group, diplopia after surgery was absent in 82.1% of patients versus 70.6% of controls. The mean duration of surgery was 54.25 ± 16.8 min with PSI application and 82.9 ± 10.8 min with pre-bent plates. The mean difference between the intact and damaged orbital volume was 1.9 ± 1.4 cm3 in the control group versus 0.74 ± 0.6 cm3 in PSI group (?<0.05). Conclusion:PEEK PSI demonstrated higher clinical efficacy in comparison to pre-bent plates in orbital wall reconstruction especially in restoring the volume and shape of the damaged orbit.
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