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Purpose: Surgical planning for Adolescent Idiopathic Scoliosis (AIS) relies on the coronal and sagittal plane to determine the lowest instrumented vertebra (LIV). Failure to include the stable sagittal vertebra (SSV) within the construct can increase the incidence of postoperative distal junctional kyphosis (DJK). The purpose of this study is to assess the variability of SSV within patients and to identify positional parameters that may lead to its change.
Methods: This is a case-control study of AIS patients with changes in SSV throughout serial radiographs. Radiographic sagittal parameters and hand positioning for the patients with changes in SSV were compared to patients with stable SSV. Additionally, a subgroup analysis was conducted to compare the positional parameters of only the patients with changes in SSV.
Results: 46 patients with a mean age of 15 ± 1.8 years old at the time of surgery were included in this study. 33/76 (43.4%) image pairs were found to have a change in SSV. Positional parameters associated with the more distally measured SSV were found to have a more negative sagittal vertebral axis (p = 0.001), more positive pelvic shift (p = 0.023), and more negative Global Sagittal Axis (p = 0.001) when compared to the more proximally measured SSV.
Conclusion: Significant variability exists in the determination of SSV in AIS patients undergoing serial radiographs. Positional parameters associated with the proximal and distally measured SSV also have variability which indicates that posture has a significant impact on this measure. Surgeons need to be aware of SSV variability during preoperative planning and must consider multiple parameters for the determination of LIV.
Level Of Evidence: 3.
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http://dx.doi.org/10.1007/s43390-020-00166-6 | DOI Listing |
Med Eng Phys
October 2025
Department of Engineering Science, University of Oxford, United Kingdom. Electronic address:
Traditionally, clinical devices are designed, tested and improved through lengthy and expensive laboratory experiments and clinical trials [1]. More recently, computational methods have allowed for rapid testing, speeding up the design process and enabling far more complete searches of design space. While computational models cannot fully capture the complexities of biological systems, they provide valuable insights into crucial underlying mechanisms, such as the effects of fluid-structure interactions (FSIs).
View Article and Find Full Text PDFAerosp Med Hum Perform
September 2025
Introduction: Military fast jet pilots face significant physical challenges, including high Gz accelerations during dynamic maneuvers. The objectives of this study were threefold: 1) to record pilot movements during real flights, 2) to quantify head and trunk movements under standardized Gz conditions and during basic fighter maneuvers (BFMs), and 3) to categorize compensatory strategies used to mitigate physical strain.
Methods: A total of 20 Eurofighter pilots (mean age: 28.
PLoS One
September 2025
School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an, China.
Accurate prediction of time-varying dynamic parameters during the milling process is a prerequisite for chatter-free cutting of thin-walled parts. In this paper, a matrix iterative prediction method based on weighted parameters is proposed for the time-varying structural modes during the milling of thin-walled blade structures. The thin-walled blade finite element model is established based on the 4-node plate element, and the time-varying dynamic parameters of the workpiece during the cutting process can be obtained by modifying the thickness of the nodes through the constructed mesh element finite element model It is not necessary to re-divide the mesh elements of the thin-walled parts at each cutting position, thus improving the calculation efficiency of the dynamic parameters of the workpiece.
View Article and Find Full Text PDFPLoS One
September 2025
Department of Radiation Oncology, Yonsei Cancer Center, Heavy Ion Therapy Research Institute, Yonsei University College of Medicine, Seoul, Korea.
Volumetric modulated arc therapy (VMAT) for lung cancer involves complex multileaf collimator (MLC) motion, which increases sensitivity to interplay effects with tumour motion. Current dynamic conformal arc methods address this issue but may limit the achievable dose distribution optimisation compared with standard VMAT. This study examined the clinical utility of a VMAT technique with monitor unit limits (VMATliMU) to mimic conformal arc delivery and reduce interplay effects while maintaining plan quality.
View Article and Find Full Text PDFJ Robot Surg
September 2025
Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, UT Health San Antonio, 7703 Floyd Curl Drive, 7836, San Antonio, TX, 78229-3900, USA.
To evaluate intraoperative ventilatory mechanics during robotic-assisted hysterectomy in obese women with endometrial cancer and introduce the concept of a physiologic "ceiling effect" in respiratory strain. We conducted a retrospective cohort study of 89 women with biopsy-confirmed endometrial cancer who underwent robotic-assisted total hysterectomy between 2011 and 2015. Intraoperative ventilatory parameters, including plateau airway pressure and static lung compliance, were recorded at five-minute intervals.
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