Introduction: Pelvic external fixation using anterosuperior pins provides a quick method of stabilization without necessitating fluoroscopic guidance. Various locations, depths, and inclinations have been cited for external fixator pins; however, the existing literature lacks clear indications for the angular difference between pins. Thus, we aimed to determine the greatest degree of sagittal pin spanning angulation (SPSA) between two iliac crest pins and how intraosseous depth (ID) affects these angulations.
Materials And Methods: A newly developed computer algorithm produced cross sections of 3D pelvic reconstructions in the sagittal plane in 5° increments. Computer-generated pins with IDs of 60, 75, and 90 mm were positioned in 5° increments transversely. Pins were assessed for cortical containment to define values for SPSA and transverse pin spanning angulation (TPSA).
Results: A bimodal distribution revealed varying degrees of insertion frequency and SPSA, cranially and caudally. The caudal distribution exhibited greater cortical containment with larger values for SPSA and TPSA. The highest insertion frequency (85.7%) and largest SPSA (155°) were observed for the 60-mm ID. Increasing ID resulted in further bony penetration and smaller values for SPSA and TPSA.
Conclusions: Expanding the degree of SPSA between inserted pins in anterosuperior pelvic external fixation can be challenging due to the thinning of the iliac wing, which affords a narrow corridor for intraosseous pin containment. An ID of 60 mm allows larger degrees of SPSA while maintaining higher rates of cortical pin containment when compared to pins with greater IDs.
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http://dx.doi.org/10.1007/s00590-020-02684-5 | DOI Listing |
JBJS Essent Surg Tech
December 2024
Division of Orthopaedic Surgery, Department of Surgical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
Background: Temporary ankle-spanning circular fixation aims to provide osseous stability while (1) allowing access to and recovery of the traumatized soft-tissue envelope and (2) facilitating safe, comfortable, and clinically relevant cross-sectional imaging for surgical planning. It is most commonly utilized in a "span-scan-plan" treatment strategy in cases of peri-articular fractures around the ankle. Conventional monolateral fixators are prone to morbidity at the half-pin sites in the foot and variation in construct stability.
View Article and Find Full Text PDFThe dynamic range of non-coherent continuous-wave (CW) THz photomixing (PM) systems with broadband detectors can be significantly limited by various parasitic effects. Specifically, we examine the generation of parasitic (i) THz and (ii) IR radiation, and (iii) higher harmonics in CW THz PM emitters. (i) The parasitic broadband THz radiation, spanning from 100 to 250 GHz with a total output power of 20 nW, results from not perfectly clean laser spectra.
View Article and Find Full Text PDFACS Omega
June 2024
School of Future Technology, Henan Key Laboratory of Quantum Materials and Quantum Energy, Henan University, Zhengzhou 450046, P. R. China.
Ultrawide bandgap (UWBG) semiconductors, including GaO, diamond, Al Ga N/AlN, featuring bandgaps greater than 4.4 eV, hold significant promise for solar-blind ultraviolet photodetection, with applications spanning in environmental monitoring, chemical/biological analysis, industrial processes, and military technologies. Over recent decades, substantial strides in synthesizing high-quality UWBG semiconductors have facilitated the development of diverse high-performance solar-blind photodetectors (SBPDs).
View Article and Find Full Text PDFAnn Saudi Med
June 2024
From the Department of Orthopedics, Al-Azhar University, Cairo, Egypt.
Background: Femoral and tibial fractures may result in delayed union and nonunion, posing significant challenges in orthopedic practice. The Ilizarov technique has emerged as a promising solution for managing these complex cases.
Objectives: Evaluate the radiographic and functional results of Ilizarov fixation in the treatment of nonunion of tibia and femur fractures.
In a previous work, we demonstrated a coupled cavity system where photons in one storage cavity can be transferred to another storage cavity at an arbitrary time by applying a voltage pulse to a third cavity placed in a p-i-n junction. In this work, we demonstrate methods to improve the transfer efficiency and photon lifetimes of such a coupled system. Firstly, we designed a photonic-crystal structure that achieves a large coupling coefficient without reducing the radiation quality factor compared to the previously proposed structure: The photonic-crystal design was changed to a more symmetric configuration to suppress radiation losses and then optimized using an automatic structure tuning method based on the Covariance Matrix Adaptive Evolutional Strategy (CMAES).
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