Inferior Edge Research Articles

Dose compensation for decreased biological effective dose due to intrafractional interruption during radiotherapy: integration with a commercial treatment planning system

Objective.While the biological effective dose (BED) has been used to estimate the damage to tumor cells in radiotherapy, BED does not consider intrafractional interruption (IFI) occurring during irradiation. We aim to develop a framework to evaluate the decrease in BED [ΔBED] and to create a plan compensating for the decrease by IFI.Approach.ΔBEDwas calculated using a model based on the microdosimetric kinetic model (MKM) for four brain tumor cases treated using a volumetric-modulated arc therapy. Four biologically compensated plans (BCPs) were created in the treatment planning system by a single-time optimization using a base plan consideringΔBEDcreated in in-house software and optimization objectives for the original clinically delivered plan to achieve a homogeneous BED distribution within the planning target volume (PTV). The BED-volume histogram was evaluated for non-compensated plan and BCP with different timepoint of interruption, a percentage of gantry rotation angle (GRA) before interruption in planned GRA,ηand duration of interruptionτ. Characteristics of the dose accumulation were analyzed for different collimator angle sets, Plan A (10°, 85°) and Plan B (45° and 315°), for the first case.Main Results.Hot spots in theΔBEDdistribution forη= 25%, 50%, and 75% were observed at superior-and-interior ends, central region, and peripheral region in PTV, respectively. These behaviors could be understood by characteristics of the MKM-based model producing maximumΔBEDat 50% of the dose accumulation.ΔBED50%ranged 4.5%-6.6%, 5.0%-7.3%, and 5.3%-7.7% forτ= 60, 90, and 120 min, respectively. Plan A showed fast dose accumulation at superior and inferior edges while slow on peripheries in the lateral dose profile. Plan B showed more homogeneous PD distributions than Plan A during irradiation.Significance.The developed framework successfully evaluated and compensated for the decreased BED distribution.

Surrogate gating strategies for the Elekta Unity MR-Linac gating system.

MRI-guided adaptive radiotherapy can directly monitor the anatomical positioning of the intended target during treatment with no additional imaging dose. Elekta has recently released its comprehensive motion management (CMM) solution that enables automatic radiation beam-gating on the Unity MR-Linac. Easily visualized targets that are distinct from the surrounding anatomy can be used to drive automatic gating decisions from the MRI cine imaging. However, poorly visualized targets can compromise the tracking and gating capabilities and may require surrogate tracking structures. This work presents strategies to generate robust tracking surrogates for a variety of treatment sites, enabling a wider application of CMM. Surrogate tracking strategies were developed from a cohort of patients treated using the CMM system on the Unity MR-Linac for treatment sites of the lung, pancreas, liver, and prostate. These sites posed challenging visualization or tracking of the primary target thereby compromising the tracking accuracy. Surrogate structures were developed using site-specific strategies to improve the imaging textured detail within the tracking volume while avoiding the dynamic overwhelming hypo- or hyper-intense anatomical structures. These surrogate volumes were applied within the anatomical positioning monitoring system as a proxy that drove the CMM gating decisions on the treatment unit. Robust site-specific surrogate structures were developed. Surrogate tracking structures for centrally located thoracic targets were created by expanding the target peripherally away from the heart and great vessels and into the lung. Pancreas surrogates required a vertically expanded column intersecting with the inferior liver edge. For the liver and prostate, surrogate structures consisted of a uniform expansion of the target, with liver surrogates intersecting the proximal liver edge or diaphragm while avoiding nearby ribs. These surrogate strategies have enabled the gating of complex moving targets among different treatment sites at our institution.

The effect of female breast surface area on skin stiffness and tactile sensitivity at rest and following exercise in the heat.

Female development includes significant morphological changes across the breast. Yet, whether differences in breast surface area (BrSA) modify breast skin stiffness and tactile sensitivity at rest and after exercise in the heat remain unclear. We investigated the relationship between BrSA and skin stiffness and tactile sensitivity in 20 young to middle-aged women (27±8years of age) of varying breast sizes (BrSA range: 147-502cm2) at rest and after a submaximal run in a warm climatic chamber (32 ± 53%±1.7% relative humidity). Skin stiffness above and below the nipple and tactile sensitivity from the nipple down were measured. Associations between BrSA and both skin stiffness and tactile sensitivity at rest were determined via correlation analyses. Effects of exercise and test site were assessed by a two-way ANOVA. Skin stiffness was positively correlated with BrSA 3cm above the areola edge (r=0.61, P=0.005) and at the superior areola border (r=0.54, P=0.016), but not below the nipple (P>0.05). The area 3cm below the areola was also significantly stiffer than all other test sites (P<0.043). Tactile sensitivity did not vary with BrSA (P>0.09), but it varied across the breast (i.e., the area 3cm below the areola was more sensitive than the inferior areola edge; P=0.018). Skin stiffness and tactile sensitivity across the breast decreased after exercise by ∼37% (P<0.001) and ∼45% (P=0.008), respectively. These findings expand our fundamental understanding of the mechanosensory properties of the female breast, and they could help to inform sportswear innovation to better meet the support needs of women of different breast sizes at rest and following exercise.

A comparative study of the efficacy of customized titanium plates versus conventional maxillary protraction in the treatment of skeletal class Ⅲ patients

Objective: To compare the clinical efficacy of customized titanium plate and conventional maxillary protraction treatment in patients with skeletal class Ⅲ malocclusion during growth spurt. Methods: During growth spurt, skeletal class Ⅲ patients with maxillary hypoplasia who were treated in the Department of Orthodontics, Capital Medical University School of Stomatology from August 2018 to July 2021 were prospectively enrolled. They were treated with maxillary protraction using customized titanium plates (customized titanium plate group) and conventional methods (conventional protraction group), respectively. Lateral cephalometric radiographs were collected before and after treatment for conventional cephalometric analysis, including SNA angle (angle between Sella, Nasion and A point), ANB angle (angle between A point, Nasion, and B point), FH-MP angle (mandibular plane angle), Y-axis angle, U1-L1 angle (upper to lower central incisor angle), U1-SN angle (upper incisor to SN plane angle), anterior and lower height, maxillary length, etc. The stable basicranial line (SBL) was used as the reference line to measure the distance from each reference point (ANS point, A point, Prn point, Sn point, UL point etc.) to the stable basicranial vertical line (VerT, the perpendicular line of the skull base line at the intersection point of the anterior wall of the sella image and the inferior edge of the anterior bed process). Paired t-tests were performed on the cephalometric data before and after maxillary protraction treatment in the two groups, and two independent samples t-tests were performed to compare the differences in the efficacy of the two maxillary protraction methods. Results: A total of 20 patients (9 males and 11 females), aged (10.8±1.3) years, were included in the personalized titanium plate group. A total of 20 patients (8 males and 12 females), aged (10.5±1.1) years, were included in the conventional protraction group. The SNA angle, ANB angle, FH-MP angle, Y-axis angle, anterior lower height, maxillary length, ANS-VerT distance, A-VerT distance, Prn-VerT distance, Sn-VerT distance, and UL-VerT distance were significantly higher than those before treatment in the two groups (P<0.05). The changes of SNA angle, ANB angle and A-VerT before and after treatment in the personalized titanium plate group [3.15°±2.28°, 4.64°±1.40°, (4.41±3.43) mm, respectively] were significantly higher than those in the traditional group [2.13°±2.69°, 2.81°±1.10°, (3.13±4.76) mm, respectively](P<0.05), and the changes of U1-L1 angle and U1-SN angle before and after treatment (-0.76°±7.42° and 1.74°±6.38°, respectively) was significantly lower than that of the control group (-5.14°±6.62° and 4.57°±5.24°, respectively, P<0.05). Conclusions: Maxillary protraction can effectively improve skeletal class Ⅲ relationships in growing patients. The linear measurements using the SBL line as a reference plane visualize the sagittal improvement in sagittal relationship after maxillary protraction. The customized titanium plate maxillary protraction treatment has a clear therapeutic effect on patients with skeletal class Ⅲ deformities, and its dental effect is relatively small.

Relationships of the vidian nerve and internal carotid artery: MRI and intraoperative surgical evaluation.

Skull base anatomy around the internal carotid artery (ICA) is extremely complex. Among anatomical landmarks studied, the vidian canal has been thoroughly evaluated, unlike the vidian nerve (VN). Our aim is to evaluate the VN-ICA relationships, and understand their role in terms of surgical planning. Fifty MRI examinations of 100 healthy petro-spheno-clival regions were reviewed in order to evaluate the relationship between the vidian nerve axis (VNA) and the petrous ICA. Twenty-seven cases of expanded endonasal approaches to petrous apex region were evaluated to check the VN-ICA relationship intraoperatively. MRI evaluations showed that, in 23% of cases, the VNA was below the edge of the ICA, in 45% it was at the edge of the ICA and in 32% it ended up above the edge of the ICA. Surgically speaking, in 9 of 28 petrous apex approaches, the VN ended above the inferior edge of the petrous carotid. MRI evaluation adds useful information in planning the surgical approach to petro-spheno-clival regions, even if the identification of VNA, in these cases, may not be radiologically possible. Surgical experience confirms the importance of VN identification in guiding the surgeon in complex cases, and also outline the possible risks of relying only on this landmark.

Cadaveric Study of Colon-Lengthening Maneuvers After Sigmoidectomy.

Creation of a tension-free colorectal anastomosis after left colon resection or low anterior resection is a key requirement for technical success. The relative contribution of each of a series of known lengthening maneuvers remains incompletely characterized. The aim of this study was to compare technical procedures for lengthening of the left colon before rectal anastomosis. A series of lengthening maneuvers was performed on 15 fresh cadavers. Mean distance gained was measured for each successive maneuver, including 1) high inferior mesenteric artery ligation, 2) splenic flexure takedown, and 3) high inferior mesenteric vein ligation by the ligament of Treitz. Cadaveric study. The premobilization and postmobilization position of the proximal colonic end was measured relative to the inferior edge of the sacral promontory. Measurements of the colonic length relative to the sacral promontory were taken after each mobilization maneuver. The inferior mesenteric artery, sigmoid colon, and rectum specimen lengths were measured. The distance from the inferior border of the sacral promontory to the pelvic floor was measured along the sacral curvature. Mean sigmoid colon resection length was 34.7 ± 11.1 cm. Before any lengthening, baseline reach was -1.3 ± 4.2 cm from the sacral promontory. Inferior mesenteric artery ligation yielded an additional 11.5 ± 4.7 cm. Subsequent splenic flexure takedown added an additional 12.8 ± 9.6 cm. Finally, inferior mesenteric vein ligation added an additional 11.33 ± 6.9 cm, bringing the total colonic length to 35.7 ± 14.7 cm. BMI and weight negatively correlated with length gained. The study was limited by nature of being a cadaver study. Stepwise lengthening maneuvers allow significant additional reach to allow a tension-free left colon to rectal anastomosis. See Video Abstract . ANTECEDENTES:La creación de una anastomosis colorrectal libre de tensión tras una resección de colon izquierdo o tras una resección anterior baja es un requisito clave para el éxito relacionado con la técnica quirúrgica. La relativa contribución de las diversas maniobras de alargamiento permanece caracterizada de manera incompleta.OBJETIVO:El propósito de este estudio fue la de comparar procedimientos técnicos de alargamiento del colon izquierdo previo a la anastomosis rectal.DISEÑO:Una serie de maniobras de alargamiento fueron realizados en 15 cadáveres frescos. La distancia promedio ganada fue medida para cada maniobra sucesiva, incluyendo (1) ligadura alta de la arteria mesentérica inferior, (2) descenso del ángulo esplénico, (3) ligadura alta de la vena mesentérica interior mediante el ligamento de Treitz.AJUSTES:Estudio cadavérico.PRINCIPALES MEDIDAS DE RESULTADO:La posición premobilizacion y postmobilizacion del extremo proximal del colon fue medido tomando en cuenta el borde inferior del promontorio sacro. Las mediciones de la longitud colónica en relación al sacro fueron tomadas luego de cada maniobra de movilización. Fueron tomadas así mismo las longitudes de la arteria mesentérica inferior, el colon sigmoides y recto. Las distancias desde el borde inferior del promontorio sacro al suelo pelvico fueron medidas a lo largo de la curvatura sacra.RESULTADOS:Average sigmoid colon resection length was 34.7 ± 11.1 cm. Prior to any lengthening, baseline reach was -1.3 ± 4.2 cm from the sacral promontory. Inferior mesenteric artery ligation yielded an additional 11.5 ± 4.7 cm. Subsequent splenic flexure takedown added an additional 12.8 ± 9.6 cm. Finally, inferior mesenteric vein ligation added an additional 11.33 ± 6.9 cm, bringing the total colonic length to 35.7 ± 14.7 cm. BMI and weight negatively correlated with length gained.LIMITACIONES:Este estudio tuvo como limitación la naturaleza de haber sido un estudio cadavérico.CONCLUSIONES:Maniobras de alargamiento permiten un alcance adicional significativo permitiendo de esta manera una anastomosis de colon izquierdo a recto libre de anastomosis. (Traducción-Dr Osvaldo Gauto ).

Localization of Mandibular Canal in Dentulous and Edentulous Regions

Objectives: Retrospective determination of the changes in the mandibular canal (MC) course in men and women in the second premolar, first molar and second molar regions of the dentulous and edentulous mandible.&#x0D; Methods: In CBCT images of 274 patients aged 18-88 years who were systemically healthy, the distances of the outer cortex of the MC to the mandible superior, lingual, inferior and buccal cortical bone border were measured in the right and left mandible 2nd premolar, 1st molar and 2nd molar regions. In these regions, the differences in MC course between left and right hemimandible, dentulous and edentulous, and males and females were examined by independent t-test and paired t-test (p&lt; .05).&#x0D; Results: As a result of the statistical analysis, statistical significance was observed in the linear measurements of the MC to the superior cortical bone border in dentulous and edentulous patients in the relevant regions. In female and male patients, the distance of the MC to the inferior cortical edge of the mandible in the dentulous and edentulous dentition was statistically less in females. The superior distance of the mandible was found to be less in the edentulous regions than in the dentulous regions.&#x0D; Conclusions: The course of the MC in the posterior mandible is generally close to the inferior and lingual wall, but it changes direction towards the superior and buccal regions as it approaches the mental foramen. Furthermore, in women, the MC is located closer to the inferior border of the mandible compared to men.

Pilot study of a novel, alternative subdermal scapular insertion site for the etonogestrel contraceptive implant

ObjectivesTo assess the pharmacokinetics and pharmacodynamics of the etonogestrel (ENG) contraceptive implant when inserted at an alternative scapular site. Study DesignWe conducted a pilot study of healthy, reproductive-age females who underwent subdermal insertion of an ENG implant over the inferior edge of the non-dominant scapula (scapular insertion). We measured serum ENG levels over one year at nine time points. Participants completed questionnaires on insertion site and bleeding side effects. We collected photographs and video recordings of insertion and removal techniques. ResultsWe enrolled five participants (as prespecified), their median age was 26.0 years (range: 19.6-30.3) and median body mass index was 25.0 kg/m2 (range: 22.0-28.0). All serum ENG concentrations remained >90pg/mL during the first year of use and were within range of published data for arm insertion of ENG implant at all time points. The mean serum ENG level was 511.7pg/mL (±168.2) at one week and 136.6pg/mL (±21.8) at 12 months. During the first week after insertion, 4/5 participants noted insertion site pain with a median pain score of 2 (range 1-3), but all noted resolution by week two. Participants reported variable bleeding patterns consistent with standard ENG implant placement. At the end of the study, all participants reported satisfaction with the implant and would recommend scapular insertion to a friend. ConclusionsScapular insertion of the ENG contraceptive implant has similar pharmacokinetics to arm insertion over one year of use. This novel, alternative site was well tolerated and demonstrated similar bleeding side effects to standard arm insertion. IMPLICATIONSSubdermal scapular insertion of the etonogestrel contraceptive implant demonstrated similar pharmacokinetics to arm insertion over one year of use. Our pilot data supports scapular insertion as an alternative site for ENG contraceptive implants, which could be beneficial for certain patient populations.

Defining Critical Humeral Bone Loss: Inferior Craniocaudal Hill-Sachs Extension as Predictor of Recurrent Instability After Primary Arthroscopic Bankart Repair

Background: The glenoid track concept for shoulder instability primarily describes the medial-lateral relationship between a Hill-Sachs lesion and the glenoid. However, the Hill-Sachs position in the craniocaudal dimension has not been thoroughly studied. Hypothesis: Hill-Sachs lesions with greater inferior extension are associated with increased risk of recurrent instability after primary arthroscopic Bankart repair. Study Design: Case-control study; Level of evidence, 3. Methods: The authors performed a retrospective analysis of patients with on-track Hill-Sachs lesions who underwent primary arthroscopic Bankart repair (without remplissage) between 2007 and 2019 and had a minimum 2-year follow-up. Recurrent instability was defined as recurrent dislocation or subluxation after the index procedure. The craniocaudal position of the Hill-Sachs lesion was measured against the midhumeral axis on sagittal magnetic resonance imaging (MRI) using either a Hill-Sachs bisecting line through the humeral head center (sagittal midpoint angle [SMA], a measure of Hill-Sachs craniocaudal position) or a line tangent to the inferior Hill-Sachs edge (lower-edge angle [LEA], a measure of Hill-Sachs caudal extension). Univariate and multivariate regression were used to determine the predictive value of both SMA and LEA for recurrent instability. Results: In total, 176 patients were included with a mean age of 20.6 years, mean follow-up of 5.9 years, and contact sport participation of 69.3%. Of these patients, 42 (23.9%) experienced recurrent instability (30 dislocations, 12 subluxations) at a mean time of 1.7 years after surgery. Recurrent instability was found to be significantly associated with LEA >90° (ie, Hill-Sachs lesions extending below the humeral head equator), with an OR of 3.29 (P = .022). SMA predicted recurrent instability to a lesser degree (OR, 2.22; P = .052). Post hoc evaluation demonstrated that LEA >90° predicted recurrent dislocations (subset of recurrent instability) with an OR of 4.80 (P = .003). LEA and SMA were found to be collinear with Hill-Sachs interval and distance to dislocation, suggesting that greater LEA and SMA proportionally reflect lesion severity in both the craniocaudal and medial-lateral dimensions. Conclusion: Inferior extension of an otherwise on-track Hill-Sachs lesion is a highly predictive risk factor for recurrent instability after primary arthroscopic Bankart repair. Evaluation of Hill-Sachs extension below the humeral equator (inferior equatorial extension) on sagittal MRI is a clinically facile screening tool for higher-risk lesions with subcritical glenoid bone loss. This threshold for critical humeral bone loss may inform surgical stratification for procedures such as remplissage or other approaches for at-risk on-track lesions.

Right Lower Sleeve Lobectomy: Detailed Technique and Perioperative Patient Management.

This report reviews our experience with right lower sleeve lobectomy and describes our technique and approach to perioperative patient management. We retrospectively reviewed 11 patients who underwent right lower sleeve lobectomy for lung cancer. Surgical techniques and perioperative management were also investigated. Bronchoplasty was performed using 4-0 absorbable monofilament sutures. The deepest portion was anastomosed using continuous sutures; interrupted sutures were used for the more superficial portions. The truncus intermedius and right middle lobe bronchus should be anastomosed in a natural position. Anastomosis patency was confirmed using intraoperative bronchoscopy. Separation of the right upper and middle lobes and pericardiotomy at the inferior edge of the superior pulmonary vein are useful for mobilizing the right middle lobe. Death during hospitalization and treatment-related death did not occur. One patient developed pneumonia, and another developed a bronchopleural fistula. We reported our technique of right lower sleeve lobectomy and our approach to perioperative patient management. Sharing knowledge is essential to completing this rare surgery.

The Rubber Band Man: An Unexpected Reason for Breathing Difficulty

A 73-year-old male presented to his physician with difficulty breathing. The patient described a nagging inability to take a deep breath, and his wife noted what appeared to be a mass on his back, that she believed had gotten bigger. He had a notable family history of soft tissues masses in numerous family members. Physical examination revealed non-painful, soft, and movable masses along the inferior edges of both scapulae, consistent with elastofibroma. Pulmonary function testing and cardiac evaluation revealed normal results. The masses remained stable in size across repeat Magnetic Resonance Imaging and were managed conservatively due to their non-impeding nature and lack of cosmetic concerns. This case highlights the importance of considering elastofibroma in patients with soft tissue masses, the significance of their physical symptomatology and the decision-making process involved in selecting appropriate management strategies based on individual patient characteristics and clinical presentations.

Anatomic feasibility study of a sartorius myocutaneous flap with a distally based pedicle and proximal skin paddle

IntroductionWe conducted an anatomic feasibility study of a sartorius myocutaneous flap with a distally based pedicle and proximal skin paddle to cover soft tissue defects of the knee region. HypothesisA recent anatomic study by Mojalla showed that the sartorius muscle had 2 distinct pedicles, making it possible to isolate this muscle on its distal pedicle and harvest it with a skin paddle. Materials and methodsThis anatomic study was conducted on 10 lower limbs. The 2 criteria assessed were (1) the viability of our proximal skin paddle and (2) the arc of rotation and coverage obtained with this myocutaneous flap. ResultsWe identified 7 proximal skin paddles after the injection of India ink into the distal pedicle of the sartorius muscle. In all cases, the arc of rotation of the flap allowed coverage of the knee region. The mean distance between the inferior edge of the skin paddle and the proximal border of the patella (DBAP) was measured at 13cm, and the mean distance between the superior edge of the flap paddle and the anterior superior iliac spine (DASIS) at 16cm. The average skin paddle size was 14 by 7cm. DiscussionOur anatomic study demonstrated the feasibility of our sartorius flap with a distally based pedicle and proximal skin paddle. This technique may be a viable alternative when using gastrocnemius flaps is not feasible, or the surgeon lacks the microsurgical skills to perform free flaps. Level of evidenceIV; descriptive anatomic study.

Direction-guided and multi-scale feature screening for fetal head–pubic symphysis segmentation and angle of progression calculation

Transperineal ultrasound imaging in the mid-sagittal plane can potentially enable the objective quantification of the level of fetal head descent in the birth canal by measuring the angle of progression (AoP). Specifically, the AoP is defined as the angle between a straight line drawn along the longitudinal axis of the pubic symphysis and a line drawn from the inferior edge of the pubic symphysis to the leading edge of the fetal head. However, the process of outlining contours and measuring AoP on ultrasound images is complex and tedious, often leading to misjudgments by physicians. In response to this challenge, we propose the fetal head–pubic symphysis segmentation network (FH-PSSNet) for automatic AoP measurement. The FH-PSSNet model is based on an encoder–decoder framework, incorporating a dual attention module, a multi-scale feature screening module and a direction guidance block. The encoder extracts the relevant features and learns the global feature correlation through a dual attention module, while the decoder utilizes skip connections to preserve spatial information. Additionally, a multi-scale feature screening module with attention mechanism is proposed to extract global contextual information, enhancing object localization. Within the decoder, a dual-branch structure generates both direction information and initial segmentation features. Finally, a direction guidance block corrects the initial segmentation features to refine the segmentation results. Experiments on two datasets demonstrate the effectiveness of the proposed method. Compared to existing approaches, our model showcases competitive performance. The FH-PSSNet significantly improves automatic segmentation and AoP measurement, reducing errors and aiding sonographers in clinical settings.

The Empty Ischial Fossa Sign: A Visual Representation of Relative Inadequate Anteversion in the Posteriorly Tilted Pelvis

BackgroundInstability is a known complication following total hip arthroplasty (THA) and is influenced by spinopelvic alignment. Radiographic markers have been investigated to optimize the acetabular cup position. This study evaluated if the empty ischial fossa (EIF) sign and the position of the trans-teardrop line were predictive of postoperative instability. MethodsAll patients who underwent THA from 2011 to 2018 at a single institution were retrospectively reviewed. Pelvic tilt was measured using a trans-teardrop line compared to the superior aspect of the pubic symphysis on standing anteroposterior pelvis radiographs. Postoperative dislocations were identified through chart review and radiographic review. The EIF sign was determined by the presence of uncovered bone below the posterior inferior edge of the acetabular component at the level of the native ischium and posterior wall on standing postoperative anteroposterior radiographs. ResultsOne thousand seven hundred fifty patients (952 anterior approach and 798 posterior approach) were included. The EIF sign was present in 458 patients (26.2%) and associated with an increased dislocation rate (3.9% vs 0.9%, P < .0001). Patients with spondylosis/instrumented fusion, and positive EIF sign had a dislocation risk of 5.1% vs 1.3% (P = .001). A postoperative outlet pelvis was not significant for increased dislocation risk (odds ratio 2.16, P = .058). Patients with combined spondylosis/fusion, posterior approach, outlet pelvis, and EIF sign had a dislocation rate of 14.5%. ConclusionsThe EIF sign was an independent risk factor for postoperative instability and may represent failure to account for pelvic tilt. Avoidance of the EIF sign during cup positioning may help reduce dislocations following THA.

Method for Quantitative Assessment of Olecranon Fossa Using 3D Hand-held Laser Scanner in the Field of Forensic Anthropology

The study is based on a creation of virtual model of olecranon fossa through 3D visualization and its usage as a sex discriminant. The study was focused on an assessment of 135 complete humeri from 47 females and 88 males. The surface of olecranon fossa was captured in a 3D image, using a Hand-held Laser Scanner (FastSCAN). The result was a 3D shape comprising two tetrahedrons with a common apex and a common lateral face. This 3D model was determined by five landmarks: the most superior point of the olecranon fossa, the most lateral point of the olecranon fossa seen on the posterior surface, the most medial point of the olecranon fossa, the point on the inferior edge of the olecranon fossa, directly in the middle, and the deepest point into the fossa. Therefore, the volume of the virtual model was equal to the total of the volumes of these two tetrahedrons. The results were processed with SPSS 17.0 using Discriminant Function Analysis. The percentage of cases classified correctly is 92.5% according to the sex determination. This study demonstrates a 3D method which can be used successfully for sex determination, especially in case of highly fragmented bones that impede traditional anthropometric analyses.

Using the Blackburne-Peel index to measure the patellar height on magnetic resonance images

To reveal the normal values of patellar height measurements using the Blackburne-Peel index on magnetic resonance (MR) images and to show the gender and age differences regarding this measurement technique. This retrospective cross-sectional study investigated 148 knee MR images, and those images were re-evaluated to find out the normal values of patellar height using the Blackburne-Peel index (BPI). An adapted measurement technique of this index was applied to MR images. The study group was analyzed regarding the sex and age differences, correlation with age was investigated, and all descriptive data were presented. Independent Samples T-test, Kruskal–Wallis variance analysis, and Spearman’s Rho correlation test was applied to calculate the results. The mean value was 0.80 ± 0.09 for the total of patients. The measurements regarding the height of the inferior edge of the patella articular surface and the length of the patella articular surface indicated a significant difference between females and males (p < 0.001 for both measurements). The descriptive data obtained from this study revealed the mean values of the whole study group, different sexes, and age groups separately. Additional studies are needed for adapting BPI on MR images and verifying the normal values of the population.

Apoptosis Signal-Regulating Kinase 1 (Ask1) Inhibition Prevents In Vivo Thrombosis without Compromising Hemostasis

Cardiovascular diseases are currently among the leading causes of death in mankind. Although significant progress has been made in prevention and treatment, the currently available pharmacological interventions have a significant rate of severe bleeding side effects due to their effect on hemostasis. Recently, we have shown that apoptosis signal-regulating kinase 1 (ASK1) plays an important role in platelet activation and thrombus formation. Here, we show that two chemically distinct ASK1 inhibitors, dose-dependently inhibited thrombin-induced phosphorylation of ASK1 and its downstream effectors MKK3/4/6, p38 MAPK, and cPLA2 in human platelets, as detected by western blotting using phospho-specific antibodies. ASK1 inhibitors also dose-dependently inhibited platelet a granule release and α IIbβ 3 activation which are the readouts for inside-out signaling events as analyzed by flow cytometry. Moreover, pretreatment of human platelets with ASK1 inhibitors completely impaired clot retraction and platelet spreading on immobilized fibrinogen two events regulated by outside-in signaling. To investigate the in-vivo effect of Ask1 inhibitor on thrombus formation, we intraperitoneally injected C57BL/6 mice with Ask1 inhibitor (1mg/kg), and the blood was withdrawn at 1-, 4-, and 24-hour time points and analyzed for in vitro thrombus formation on collagen matrix under arterial flow. Ask1 inhibitor significantly decreased thrombus growth ( P&amp;lt;0.01) which was sustained for at least 24 hours. Platelet adhesion to collagen was not affected as determined by surface coverage.In a 10% FeCl 3 -induced carotid artery injury model of thrombosis, we found that Ask1 inhibitor (100μg/kg)showed a significantly extended time of vessel occlusion ( P&amp;lt;0.01) . Moreover, Ask1 inhibitor (100μg/kg) treated C57BL/6 mice were protected from collagen/epinephrine-induced pulmonary thromboembolism ( P&amp;lt;0.001). Furthermore, in a well-established ischemic stroke model of transient middle cerebral artery occlusion, C57BL/6 mice treated with Ask1 inhibitor (1mg/kg) showed increased survival and improved neurological deficits than vehicle treated mice. The extent of the brain damage was assessed by staining the brain sections with 2% 2,3,5-triphenyltetrazoliun chloride, which showed significant reduction in infarct size and edema ( P&amp;lt;0.0001). Interestingly, mice treated with Ask1 inhibitor (1mg/kg), a 10-fold more than the amount needed to inhibit thrombosis, had no effect on hemostasis as observed by both the tail bleeding assay and laser-induced cremaster injury model. Whereas clopidogrel (5-30mg/kg) showed significantly increased ( P&amp;lt;0.0001) tail bleeding time. Next, we performed cerebral bleeding assay in which brain injury was induced by inserting a 26-gauge needle through the skull in the cerebrum 2mm laterally to the bregma and 4mm deep into the cerebrum and rotated 360 degrees. After 20 minutes the extent of bleeding in the brain was assessed by imaging. Treatment of C57BL/6 mice with clopidogrel (30mg/kg) showed significantly enhanced bleeding ( P&amp;lt;0.05) compared to vehicle treated mice. However, Ask1 inhibitor treated mice had same extent of bleeding as that of vehicle treated mice. Additionally, a liver bleeding assay was performed by excising a calibrated piece (~4-5mg) of inferior edge of the right lobe of the liver of the mouse under anesthesia. After 20 minutes the bleeding was assessed by counting red blood cells in the peritoneal lavage. As observed in brain bleeding assay, treatment of mice with clopidogrel (30mg/kg), showed significantly increased liver bleeding ( P&amp;lt;0.05) compared to vehicle treated mice whereas Ask1 inhibitor treated mice had same extent of liver bleeding as that of vehicle treated mice. Taken together, our results provide evidence that ASK1 inhibitors are novel therapeutic agents to combat thrombotic disorders without any side effects of bleeding, which is inherent to current anti-thrombotic drugs.

A comparative analysis of intraglottal geometry and velocity flow fields: Excised human, canine, and synthetic vocal fold models

Synthetic vocal fold models imitate the characteristics of human vocal folds and offer advantages over tissue models, such as accessibility and prolonged lifespan, all while producing comparable vibration frequencies to those in humans. Nonetheless, due to their simplified design, they may not fully capture the intricate behavior observed in tissue models like the canine larynx model. Canine larynges, like human’s, exhibit a vertical mucosal wave, which yields a phase delay between the inferior and superior edges of the vocal folds free margin. Consequently, a divergent glottis forms during closing, producing intraglottal flow separation vortices (FSVs) that increase voice loudness and intelligibility. To bridge the knowledge gap between silicone and tissue vocal fold models, we compared the intraglottal geometry and velocity flow fields during phonation of these three models. At low subglottal pressures, the synthetic model displayed small divergence angles and no flow separation, where both tissues models exhibited FSVs. At higher pressures, FSVs observed in tissue models were correlated with increased glottal flow waveform skewing and higher MFDR values. These findings highlight why the excised canine larynx model should be the preferred choice over synthetic vocal fold models for studying the aerodynamics and fluid-structure interaction during phonation.

Imbrication of Anterior Digastric with Advancement of the Posterior Digastric and Its Implications in Neck Aesthetics.

Background: To describe a novel technique to modify the proportional length of the anterior-to-posterior digastric muscles to improve neck aesthetics. Objective: To provide an objective measure to quantify neck rejuvenation and a novel technique to adjust the digastric ratio. Design: We retrospectively compared 52 patients who had neck rejuvenation with or without digastric manipulation. Preoperative and postoperative images were analyzed and compared with computer software using a novel analysis technique to measure the digastric ratio and neck height. Distances between the menton, cervical point (CP), and gonion were measured. Results: The anterior-to-posterior digastric ratio improved an average of 26.5% (p < 0.01) in the new technique group, 15.9% in the control group. Distance of the CP to the inferior edge of the mandible decreased an average of 13.9% using the new technique. Conclusion: The ratio of anterior-to-posterior digastric muscle appears to improve as well as the neck height with manipulation of the digastric muscles.

Plate prebending using a three-dimensional-printed model affords effective anatomical reduction in clavicular shaft fractures.

A precontoured plate rarely fits properly within the patient's clavicle and must be bent intraoperatively. This study aimed to determine whether anatomical reduction could be achieved using a plate bent before surgery. This study included 87 consecutive patients with displaced mid-shaft clavicle fractures who underwent plate fixation and were followed-up for a minimum of 1 year. After exclusions, 39 consecutive patients underwent fixation with a precontoured plate bent intraoperatively (intraoperative bending group), and 28 underwent fixation with the plate bent preoperatively (preoperative bending group). Using free software and a three-dimensional (3D) printer, ipsilateral clavicle 3D-printed models were constructed. Using plain radiographs, the distance between the edge of the lateral inferior cortex and the medial inferior cortex was measured. The angle between the line connecting the inferior cortex edge and the line passing through the flat portion of the superior cortex of the distal clavicle was measured. Mean length differences between the ipsilateral and contralateral clavicle were smaller on both anteroposterior (AP; P=0.032) and axial images (P=0.029) in the preoperative bending group. The mean angular differences on both AP (P=0.045) and axial images (P=0.008) were smaller in the preoperative bending group. No significant differences were observed between the two groups in functional scores at the last follow-up. Smaller differences in length and angle between the ipsilateral and contralateral clavicle, indicative of reduction, were observed in the preoperative bending group. Using the precontoured technique with low expense, the operation was performed more effectively as reflected by a shorter operation time. Level of evidence: III.