Center Of Head Research Articles

What happens to the gluteus medius in young and middle-aged patients with hip dysplasia?

Much research has focused on quantifying the bony characteristics of patients with developmental dysplasia of the hip (DDH). Far less attention, however, has been paid to muscle abnormalities around the hip such as those in the gluteus medius (GM). We retrospectively examined clinical and imaging data, such as the age of onset and computed tomography (CT) findings, in 108 consecutive hips. Subjects for the control group were selected from our radiology database. Two readers independently evaluated the length (LGM), cross-sectional area (CSA), width (WGM), and thickness (TGM) of the GM and arm of GM (AGM) and angle of the GM activation (AOA) and bony parameters including the acetabulum-head index (AHI), lateral central edge angle (LCEA), acetabular index (AI), femoral offset (FO), and height of the rotation centre of femoral head (HCFH) among all cases using the imaging data. The patient group included 108 hips. The AGM, LGM, CSA, and TGM were lower in the DDH patients, while AOA was higher. However, there was no significant difference in the WGM between the two groups. Multiple linear regression analysis showed that AGM and AOA were independent factors affecting LCEA. The following regression equation was used: Y(LCEA) = 5.377 * X1 (AGM) - 0.310 * X2 (AOA) - 11.331. The mechanical characteristics of the GM and many bony parameters were significantly correlated (the AGM and AHI, LCEA, AI, FO, but not HCFH; AOA and AHI, LCEA, AI, but not FO or HCFH). The CSA was positively correlated with only HCFH. The rest were not statistical significance linear correlation. The multivariate regression results showed that the age of onset was positively correlated with AGM (r = 0.467). The regression equation used was Y = 9.0 * X (age of onset) - 11.4. We found difference in the morphological and mechanical characteristics of the GM between hips with DDH and hips of normal morphology. Of note, the mechanical characteristics of the GM were influenced by bony parameters in patients with DDH.

The role of the macular interface in the diagnosis of retinopathy of prematurity on the «Key to Diagnosis I » platform

AbstractPurposeTo minimize the risk of medical error in the diagnosis and choice of treatment of ROP by improving the quality and analysis of modeled wide‐field images on the Key to Diagnosis I platform.Methods1278 RetCam images of ROP 272(544 eyes) were divided into 5 groups 1‐I stage 152(304 eyes), 2‐II stage 45(90 eyes), 3‐III stage 8(12 eyes), 4‐posterior aggressive ROP 7(14 eyes), 5‐retinal immaturity 60(120 eyes); A standard clinical examination, analysis of wide‐field retinal images, macula localization and traction index of the macular region (Tm) calculation were performed. Tm is a leght‐to‐width attitude of ellipse goes through the center of optic nerve head and arcades.ResultsPlatform modules have been developed for automatic modeling of wide‐field retinal images and localization of the macula, which is a reference point for centering wide‐field images and assessing the extent of pathological changes. In the ROP group, a significant inverse correlation was observed between the values of Tm, 1A‐0.8 ± 0.03, 1B‐0.75 ± 0.04, 1B‐0.74 ± 0.13, 1D‐0.99 ± 0.01, 1D‐0.91 ± 0.09.DiscussionThe macular area can be described by ellipse, which form correlate with refraction [1]. The influence of the traction component on the macular zone connected with decrease in refractive pathology in the treatment Anti‐vascular endothelial growth factor [2].ConclusionsAt ROP Tm reflects the severity of traction processes at the retina periphery and marks the severity of pathology in case of diagnostic defects. The macula localization determines the stable points: the optic nerve disc physiological excavation center, temporal arcades and the macula circumference for photogrammetry of 3D eye model. Hill D. Retinal characteristics of myopic eyes in a semi‐rural UK population. Diss. Aston University, 2019. Sankar M. J., Sankar J., Chandra P. Anti‐vascular endothelial growth factor drugs for treatment of retinopathy of prematurity. Cochrane Database of Systematic Reviews. 2018; 1.

The Plantar Fascia Talar Head Correlation: A Radiographic Parameter with a Distinct Threshold to Validate Flatfoot Deformity and Its Corrective Surgery on Conventional Weightbearing Radiographs

Category:Hindfoot; Midfoot/ForefootIntroduction/Purpose:Corrective surgery for flexible flatfoot deformity (FD) remains controversial, and one of the main reasons for this is the lack of standardised radiographic measurements to define an FD. Previously published radiographic parameters to differentiate between a specimen with and without FD do not have a commonly accepted and distinct threshold. Such a parameter would help validate FDs and the required corrective surgery. The purpose of this study was to assess a new conventional radiographic parameter with a distinct threshold that allowed the differentiation between feet with and without an FD and evaluate its application in corrective surgery for FD.Methods:The plantar fascia-talar head correlation (PTC) with its defined threshold was assessed by measuring the distance between the medial border of the plantar fascia [a connecting line between the medial border of the tibial sesamoid and the calcaneal insertion of the plantar fascia (mPCal)] and the centre of the talar head (DPT) on conventional dorsoplantar and lateral weightbearing radiographs; the authors were blinded to the clinical diagnosis of the 189 patients' first visits. Feet were grouped into specimens with and without an FD based on clinical examination. Then, the effect of surgical correction of FD on PTC was retrospectively evaluated on 38 patients. The intra-class correlation (ICC2) of the intra-observer reliability and the ICC2 of the inter-observer reliability of DPT measurement of 50 randomly selected specimens were calculated. The results of PTC were compared to the measurements of the lateral talar-1st metatarsal angle and the talonavicular uncoverage angle.Results:The intra-class correlation (ICC2) of the intra-observer reliability of DPT measurement was 0.95 (95%-confidence interval CI95[0.92, 0.97]), the ICC2 of the inter-observer reliability was 0.93 (CI95 [0.89, 0.95]). PTC, lateral talar first metatarsal angle and talonavicular uncoverage angle showed a statistically significant difference between the specimens with and without a FD (Wilcoxon test p-values <0.001). However, only the discriminatory power of PTC was distinct. The sensitivity and specificity of PTC was 0.88 (95%CI: 0.77-0.95) and specificity 0.96 (95%CI: 0.92-0.98), respectively, to identify an FD, consistent with the clinical examination. The identification of a sagittal plane FD caused by midfoot osteoarthritis on a lateral conventional weightbearing radiograph before measuring DPT increased the sensitivity for the combined method to 0.98 (95%CI: 0.9-1). Thirty-five of 38 surgeries successfully corrected the FD and PTC comparable to that in subjects without an FD. The unsuccessful corrections did not adequately correct the PTC.Conclusion:PTC is a unique and reliable radiographic parameter with an excellent threshold to confirm an FD, can be used intraoperatively to titrate the required amount for correction of FD under simulated weightbearing fluoroscopic imaging and is therefore useful to monitor and validate sufficient correction of its reconstructive surgery.PTC is an objective radiographic measurement to reliably describe the clinical subjective conclusion of any kind of FD with the exception FDs caused by an explicit midfoot pathology.

Weight Bearing CT Analysis of the Transverse Tarsal Joint During Eversion and Inversion

Category:Basic Sciences/Biologics; HindfootIntroduction/Purpose:Current understanding of the kinematics of the transverse tarsal joint continues to evolve. Unfortunately, most prior studies have been in cadavers or under non-physiologic conditions. Weight bearing CT scans may provide more accurate in vivo information about the position of the transverse tarsal joint during eversion and inversion.Methods:Institutional Review Board approval was obtained. Five normal volunteers underwent bilateral weight bearing cone- beam PedCAT scans (CurveBeam LLC, Hatfield, PA) while standing on platforms that positioned both hindfeet in 20o of valgus and then 20o of varus. The CT scans had a field-of-view diameter of 350 mm and a field-of-view height of 200 mm. The scan exposure time was 9 seconds, with a total scan time of 54 seconds. The datasets were reconstructed using filtered back projection with 0.37mm isotropic voxels. The resulting volumes were then segmented, identifying the [x, y, z] coordinates that comprised each bone. Each bone of the hindfoot was segmented on the scan images and the motion between the talus and calcaneus was analyzed. A similar analysis was done for motion between the navicular and cuboid. Two-tailed paired Student's t- tests were used to compare the angle and distance measurements between valgus and varus positions.Results:In the coronal plane, the axis of the talus rotated by 17.0° relative to the axis of the calcaneus as the hindfoot moved from eversion to inversion (p=0.03). The distance between the centers of the talar head and the anterior calcaneus also moved closer to each other by 7.1 mm (p=0.00005). There was no significant change in angle or distance between the navicular and cuboid when moving from eversion to inversion. The angle between the navicular and cuboid axes changed 2.1° (p=0.7), while the distance changed 0.8 mm (p=0.7)Conclusion:Previous work proposed that the transverse tarsal joint locking mechanism occurs from the talonavicular and calcaneocuboid joint axes diverging (less parallel) as the hindfoot inverts. The current weight bearing CT data shows that not only do the talar and calcaneal axes rotate relative to each other during inversion, but the center of the talar head and anterior calcaneus translate to move closer together. Because the navicular and cuboid do not move, transverse tarsal joint locking may occur due to tightening of the joint capsules and ligaments. Further in vivo study is warranted, especially under dynamic weightbearing conditions.

Is an x-ray of the knee sufficient to assess the alignment of the leg? A study of total joint replacement with surgical navigation.

Background: Understanding the femorotibial mechanical axis (FTMA) of the leg is a necessary requirement to assess the outcome of total knee replacement (TKR). Short radiographs, which only capture the knee joint and do not include the center of the femoral head and center of the ankle, only provide us the anatomical axis (FTAA), and not the FTMA. The purpose of this study was to compare the FTMA and FTAA before and after navigated TKR. Methods: In 130 patients undergoing surgery to implant the same TKR model, an x-ray was taken including the hip, knee and ankle. Images were analysed using a computer program that calculates the mechanical and anatomical axis of the femur, tibia and femorotibial joint. An image-free navigation system with femorotibial tensioned gap technique was used for the arthroplasty implantation. After surgery, a new long x-ray was taken, where the measurements indicated above were taken again. Results: Pre-operative x-rays showed a mean difference of 6º between FTAA and FTMA (p&lt;0.001). No significant interaction was seen with patient height, but it was in patients with varus deformity and higher BMI (p=0.029); the greatest discrepancy between the anatomical and mechanical axis of the limb was found in individuals with excess weight. After TKR, the mean FTMA was modified to achieve a neutral axis (180° ±3°), as well as a concentration of the figures that showed great pre-procedure disparity, which was verified by the difference in the pre- and post-operative SD (11.85 versus 3.13). The maximum difference between FTAA and FTMA, which stood at 18º before decreased to 5.5º post-TKR. Conclusions: There is a major discrepancy between the FTAA and FTMA that increases when there is pre-operative varus deformity and in patients with excess weight. After TKR, the FTMA became concentrated, and the mean axis shifted towards the neutral axis. Performing x-rays that only include the knee is not useful for assessing the limb’s alignment prior to or after TKR.

The COVID-19 pandemic and its consequences for the diagnosis and therapy of head and neck malignancies.

The COVID-19 pandemic and the measures accompanying it have been accused of having a negative influence on the frequency and methods of treatment of various diseases including head and neck cancer (HNSCC). To go further into this assumption, the diagnoses made, and treatments performed at one of Germany's largest head and neck cancer centres were evaluated. This study consisted of one single centre and involved a retrospective review of all patients with newly diagnosed or recurrent HNSCC. The diagnosis and treatment methods used in the pre-COVID-19 time period between March 1st, 2019, and March 1st, 2020, were analysed and compared with the COVID-19 time period from April 1st, 2020, until April 1st, 2021. The primary objective was defined as the number of malignant diagnoses and the secondary objectives as the disease stage and the time to therapy. A total of 612 patients (160♀; mean 63 yrs.) were included. 319 patients (52%) were treated in the pre-COVID-19 time. The two groups did not differ in terms of age (p=0.304), gender (p=0.941), presence of recurrent disease (p=0.866), tumour subsite (p=0.194) or the duration from presentation to the multidisciplinary tumour board until start of therapy (p=0.202). There were no significant differences in the T stage (p=0.777), N stage (p=0.067) or UICC stage (p=0.922). During the pre-COVID-19 period more patients presented with distant metastases (n= 23 vs. n=8; p=0.011). This study shows that there was no significant change in either the number and severity of HNSCC diagnoses or the time until start of therapy at this large head and neck cancer centre as a result of the COVID-19 pandemic.

Three-Dimensional Evaluation of Innominate Bone Rotation in Female Patients with Developmental Dysplasia of the Hip.

BackgroundPatients with developmental dysplasia of the hip (DDH) are known to have abnormal pelvic morphologies; however, rotation of innominate bone features remains unclear. Thus, we investigated innominate bone rotation in patients with DDH by measuring the associated angles and distances using three-dimensional (3D) computed tomography.MethodsWe defined four straight lines in pelvic 3D models: from the anterior superior iliac spine to the posterior superior iliac spine, from the anterior inferior iliac spine to the posterior inferior iliac spine, from the pubic tubercle to the ischial spine, and from the pubic tubercle to the ischial tuberosity. Similarly, we measured the angles formed by these lines using the vertical axis of the anterior pelvic plane on the horizontal plane and the horizontal axis on the sagittal plane. Additionally, we measured the distances between the femoral head centers and the acetabular centers in the coronal plane.ResultsThe difference in internal rotation angle between the superior and inferior parts of the iliac bone was significantly lower, by approximately 1.7°, in the DDH group than in the control group (p = 0.007); the difference between the inferior and superior parts of the ischiopubic bone was significantly higher, by approximately 1.5°, in the DDH group (p < 0.001). In the sagittal plane, the sum of the superior aspect of the iliac bone and the inferior aspect of the ischium was significantly lower in the DDH group (p = 0.001) than in the control group. The distances between the femoral heads and the acetabula were significantly greater in the DDH group than in the control group (p = 0.03, p < 0.01, respectively).ConclusionsPatients with DDH had a more internally rotated ilium and ischiopubic bone than normal individuals; however, it should be emphasized that internal rotation was reduced near the acetabulum, and the acetabulum was shifted laterally. Similarly, it was shown that patients with DDH had different rotations of the ilium and ischiopubic bone in the sagittal plane.

Video Crowd Localization With Multifocus Gaussian Neighborhood Attention and a Large-Scale Benchmark.

Video crowd localization is a crucial yet challenging task, which aims to estimate exact locations of human heads in the given crowded videos. To model spatial-temporal dependencies of human mobility, we propose a multi-focus Gaussian neighborhood attention (GNA), which can effectively exploit long-range correspondences while maintaining the spatial topological structure of the input videos. In particular, our GNA can also capture the scale variation of human heads well using the equipped multi-focus mechanism. Based on the multi-focus GNA, we develop a unified neural network called GNANet to accurately locate head centers in video clips by fully aggregating spatial-temporal information via a scene modeling module and a context cross-attention module. Moreover, to facilitate future researches in this field, we introduce a large-scale crowd video benchmark named VSCrowd (https://github.com/HopLee6/VSCrowd), which consists of 60K+ frames captured in various surveillance scenes and 2M+ head annotations. Finally, we conduct extensive experiments on three datasets including our VSCrowd, and the experiment results show that the proposed method is capable to achieve state-of-the-art performance for both video crowd localization and counting.

Variability of Retinal Vessel Tortuosity Measurements Using a Semiautomated Method Applied to Fundus Images in Subjects With Papilledema.

PurposeTo develop methods to quantitatively measure retinal vessel tortuosity from fundus images acquired in subjects with papilledema and assess sources of variability in these measurements.MethodsDigital fundus images from 30 eyes of subjects with untreated idiopathic intracranial hypertension and papilledema were analyzed. Retinal vein and artery tortuosities for three to four vessels of each type were measured in a region of interest 1.8 to 2.7 mm from the center of the optic nerve head. Measurements were averaged to generate a venous tortuosity index (VTI) and arterial tortuosity index (ATI) for each eye. One image of each eye was analyzed two times by the same rater. Two images of each eye, differing by focal depth, were analyzed by the same rater. Correlations between VTI and ATI for the same image and different images were calculated.ResultsIntrarater Pearson correlations (r) were 0.8 (95% confidence interval [CI], 0.59–0.9) and 0.90 (95% CI, 0.73–0.96) for VTI and ATI, respectively, with one outlier removed. Interimage r values were 0.72 (95% CI, 0.48–0.87) and 0.96 (95% CI, 0.89–0.99) for VTI and ATI, respectively, with one outlier removed. The intraclass correlation coefficients for agreement and consistency were similar, suggesting that the discrepancy between measurements was due to residual random error.ConclusionsThe finding of similar intrarater and interimage variability suggests that intrarater variability may be a more dominant source than physiology and image acquisition.Translational RelevanceStandardizing rater procedures and averaging multiple measuring sessions are strategies to reduce variability and improve reliability of detecting retinal vessel tortuosity changes in images of eyes with papilledema.

Prognostic factors in acinic cell carcinoma of the head and neck: The Amsterdam experience

IntroductionThe aim was to analyse prognosticators in acinic cell carcinoma (AciCC) in two head and neck referral centers in Amsterdam, the Netherlands. Materials and methodsEighty- nine cases of AciCC treated between 1979 and 2016 were retrospectively reviewed. Five, − 10 -and 20- year estimates of survival were executed as well as univariate analysis of prognosticators. ResultsThe majority of AciCC were T1-T2; 89%. Two percent had nodal disease (2%). The most affected organ was the parotid gland (84%) with a female preponderance (67%). Mean age was 52 years with most cases diagnosed in the fourth to sixth decade. The majority of patients received adjuvant radiotherapy. Elective neck dissection (END) in the N0 neck showed no metastases. High grade transformation (HGT) was found in 21% of cases. Median follow up was 101.9 months. Median time to recurrence was 26 months. Nine patients developed distant metastases (DM) of whom 6 had HGT-AciCC. Median survival with DM was 7 months. Five,- ten -and twenty- year estimates were 84%, 81% and 81% for recurrence free survival respectively. Negative clinical features were advanced stage disease and tumour size > 2.6 cm. Negative histological features were a high mitotic rate, HGT, close and involved surgical margins and necrosis. ConclusionAciCC- HGT excluded- of the head and neck has an excellent prognosis and shows acceptable long term results. END can be considered as part of the standard treatment due to the relative high incidence of HGT- AciCC and low accuracy of cytology.

IASSIST gone glocal

Welcome to the special double issue of IASSIST Quarterly 2021 (IQ vol. 45(3-4) 2021). IASSIST is an acronym. You may think that the word is the contraction of the two words 'I assist'. In my mind, you are right! Whether the word IASSIST or the long explanation of seven words came first is the problem of the chicken and the egg. However, it is undisputed that when it is spelled out, the first I in IASSIST is for International. That has been so from its founding in 1974. Having IASSIST members in USA, Canada, and some (west) European countries was for a long time what we myopic westerners considered to be international. It is with great pleasure that IASSIST Quarterly now presents a double issue from a regional workshop in Africa. Even in 2021, it is only a small number of IASSIST's members who are from regions not part of the western world. However, having a special issue from the African region is an important contribution to making IASSIST truly international. The phrase 'think globally, act locally' is a good framing of the compressed word 'glocal'. This special issue was compiled by guest editors Winny Nekesa Akullo and Robert Stalone Buwule, and they were also behind the Africa Regional Workshop that took place at Makerere University (Kampala, Uganda) on January 11 to 13, 2021. Winny Nekesa Akullo works as Head, Library and Documentation Centre at Public Procurement and Disposal of Public Assets Authority in Uganda, and is the IASSIST Africa Regional Secretary. Robert Stalone Buwule is Senior Assistant Librarian at Kyambogo University, also in Uganda. The themes of the workshop addressed a world issue: 'Data Literacy as a catalyst for achieving Sustainable Development Goals (SDGs)'. Thus, global problems were addressed from a local viewpoint. Great thanks to Winny and Robert for their lead in the arrangement of the workshop and extra thanks to them for collecting, editing, and making the papers of the regional workshop available to us all, and for making the regional international and the local global. Enjoy the reading! Karsten Boye Rasmussen - December 2021

Elimination of the Femoral Neck in Measuring Femoral Version Allows for Less Variance in Interobserver Reliability.

Background and Objectives: Producing consistent measures of femoral version amongst observers are necessary to allow for an assessment of version for possible corrective procedures. The purpose of this study was to compare two computed tomography (CT)-based techniques for the reliability of measuring femoral version amongst observers. Materials and Methods: Review was performed for 15 patients post-femoral nailing for comminuted (Winquist III and IV) femoral shaft fractures where CT scanograms were obtained. Two CT-based techniques were utilized to measure femoral version by five observers. Results: The mean femoral version, when utilizing a proximal line drawn down the center of the femoral head-neck through CT, was 9.50 ± 4.82°, while the method utilizing the head and shaft at lesser trochanter centers produced a mean version of 18.73 ± 2.69°. A significant difference was noted between these two (p ≤ 0.001). The method of measuring in the center of the femoral head and neck produced an intraclass correlation coefficient (ICC) of 0.960 with a 95% confidence interval lower bound of 0.909 and upper bound of 0.982. For the method assessing version via the center of the head and shaft at the lesser trochanter region, the ICC was 0.993 with a 95% confidence interval lower bound of 0.987 and an upper bound of 0.996. Conclusions: The method of measuring version proximally through a CT image of the femoral head–neck versus overlaying the femoral head with the femoral shaft at the most prominent aspect of the lesser trochanter produces differing version measurements by roughly 10° while yielding an almost perfect interobserver reliability in the new technique. Both techniques result in significantly high interobserver reliability.

Evaluation of the head protection effectiveness of cyclist helmets using full-scale computational biomechanics modelling of cycling accidents

Introduction: Cycling is a popular choice for urban transportation. Helmets are important and the most popular means of head protection for cyclists. However, a debate about the effectiveness of helmets in protecting a cyclist’s head from injury continues. Method: We employed computational biomechanics methods to analyze the head protection effectiveness of nine off-the-shelf-helmets for two typical impact scenarios that occur in cycling accidents: cyclist’s head impacting a kerb (kerb-impact) and cyclist skidding (skidding impact) on the road surface. We conducted drop tests for all nine analyzed helmets, and used the test data for validation of the corresponding helmet finite element (FE) models created in this study. The validated helmet models were then used in the full-scale computer simulations (FE analysis for the skull, brain and helmet, and multibody dynamics for the remaining segments of the cyclist’s body) of the cycling accidents for cyclists wearing a helmet and without a helmet. Results: The results indicate that helmets can reduce both the peak linear acceleration of the cyclist head center of gravity (COG) and the risk of cyclist skull fracture. However, higher rotational acceleration of the head COG was predicted for cyclists wearing helmets. The results obtained using the injury criteria that rely on the brain deformations (maximum shear strain MPS and cumulative strain damage measure CSDM) suggest that helmets may offer protection in all the analyzed cyclist impact scenarios. However, the predicted level of protection varies for different helmets and impact scenarios with appreciable variations in the predictions obtained using different injury criteria. Reduction in the maximum principal strain (MPS0.98) for helmeted cyclists was predicted for both impact scenarios. In contrast, wearing the helmet reduced the CSDM only for the skidding impact scenario. For the kerb-impact scenario, no clear influence of the helmet on the predicted CSDM was observed.

성격과 선호색을 통한 자아 탐색

In branding and brand management, forming a close emotional bond with consumers is crucial. In the pursuit of cultivating an attachment relationship with consumers, the choice of color is important in the process of exploring and understanding the consumer’s “self”. This study examined whether color preference of individuals can help understand their self. Eighty(42 males, 38 females) individuals with an average age of 35(SD=7.46) years participated. Their personality was classified, and their preferred colors were investigated using the Enneagram personality test, which is a self-diagnostic tool. Descriptive statistical analysis was conducted using PASW Statistics 18 followed by a focused literature review to contextualize the results. It was found that the “body center” type preferred cold colors, and the “head center” type preferred warm colors. The “heart center” type accepted both cold and warm colors. In addition, a pattern of the expression of the self, as reflected in the preferred color, was derived. With respect to the mental aspect, the preferred color was related to pursuing the will as opposed to the expression of the self. In the emotional aspect, the preferred color was related to generating a stimulus that controls the problem of latent emotions. In summary, this study derived an understanding of how preferred colors express the mind and emotions of the self. The results suggest that it is possible to search for the self by analyzing color preference, which reflects the self to an extent.

Development and external validation of a prediction model for tube feeding dependency for at least four weeks during chemoradiotherapy for head and neck cancer

Patients who receive chemoradiotherapy or bioradiotherapy (CRT/BRT) for locally advanced head and neck squamous cell carcinoma (LAHNSCC) often experience high toxicity rates interfering with oral intake, causing tube feeding (TF) dependency. International guidelines recommend gastrostomy insertion when the expected use of TF exceeds 4 weeks. We aimed to develop and externally validate a prediction model to identify patients who need TF≥4 weeks and would benefit from prophylactic gastrostomy insertion. A retrospective multicenter cohort study was performed in four tertiary head and neck cancer centers in the Netherlands. The prediction model was developed using data from University Medical Center Utrecht and the Netherlands Cancer Institute and externally validated using data from Maastricht University Medical Center and Radboud University Medical Center. The primary endpoint was TF dependency ≥4 weeks initiated during CRT/BRT or within 30 days after CRT/BRT completion. Potential predictors were extracted from electronic health records and radiotherapy dose-volume parameters were calculated. The developmental and validation cohort included 409 and 334 patients respectively. Multivariable analysis showed predictive value for pretreatment weight change, texture modified diet at baseline, ECOG performance status, tumor site, N classification, mean radiation dose to the contralateral parotid gland and oral cavity. The area under the receiver operating characteristics curve for this model was 0.73 and after external validation 0.62. Positive and negative predictive value for a risk of 90% or higher for TF dependency ≥4 weeks were 81.8% and 42.3% respectively. We developed and externally validated a prediction model to estimate TF-dependency ≥4 weeks in LAHNSCC patients treated with CRT/BRT. This model can be used to guide personalized decision-making on prophylactic gastrostomy insertion in clinical practice.

The Plantar Fascia Talar Head Correlation: A Radiographic Parameter With a Distinct Threshold to Validate Flatfoot Deformity and Its Corrective Surgery on Conventional Weightbearing Radiographs

Background: Corrective surgery for flexible flatfoot deformity (FD) remains controversial, and one of the main reasons for this is the lack of standardized radiographic measurements to define an FD. Previously published radiographic parameters to differentiate between a foot with and without an FD do not have a commonly accepted and distinct threshold. Methods: The plantar fascia–talar head correlation (PTC) with its defined threshold was assessed by measuring the distance between the medial border of the plantar fascia and the center of the talar head (DPT) on conventional dorsoplantar and lateral weightbearing radiographs; the authors were blinded to the clinical diagnosis of the 189 patients’ first visits. Feet were sorted into groups with and without an FD based on their clinical examination. The effect of operative corrections of FD on the PTC was retrospectively evaluated on an additional 38 patients. Results: The sensitivity of the PTC was 0.98 (95% CI: 0.9-1) and specificity 0.96 (95% CI: 0.92-0.98), respectively, to identify an FD, consistent with the clinical examination. Thirty-five of 38 surgeries sufficiently corrected the FD and the PTC comparable to that in subjects without an FD. Three corrections with a residual FD did not adequately correct the PTC. Conclusion: The PTC is a reliable radiographic parameter with a distinct threshold that is sensitive and specific for the differentiation of feet with and without an FD including feet with and without residual FD after corrective surgery. The PTC is applicable to monitor the needed intraoperative amount of correction using simulated weightbearing fluoroscopy. Level of Evidence: Level III, diagnostic.

Comparison between cup implantations during total hip arthroplasty with or without a history of rotational acetabular osteotomy.

Total hip arthroplasty (THA) after rotational acetabular osteotomy (RAO) is technically demanding because of the characteristic acetabular morphology after RAO. The present study aimed to investigate the differences in the three-dimensional cup position between THA after RAO and primary THA. We analysed the pre-operative and post-operative computed tomography (CT) data of 120 patients (20 patients after RAO and 100 patients without a history of RAO) who underwent THA between January 2017 and June 2018. We evaluated radiographic parameters, including acetabular anteversion, antero-posterior distance at the level of the femoral head centre, the presence of anterior acetabular osteophyte and/or rotated fragment during RAO from the CT data. Additionally, operative data and clinical scores were also evaluated. Although we found no significant differences in any clinical parameters, there were significant differences in radiographic parameters and operative data. The morphology of the acetabulum was significantly retroverted, and the antero-posterior distance was longer in patients after RAO, compared to the implanted cup. Additionally, longer operative time was necessary for such patients. These results reflect the atypical acetabular morphology after RAO, and emphasize that care should be taken to avoid anterior bony impingement and post-operative dislocation. For cup implantation during THA after RAO, surgeons should acknowledge the atypical morphology of the acetabulum and not be misled by its visual shape.

Computational simulation of cephalomedullary nailing in the osteoporotic Asian femur and clinical implications

PurposeTo assess the conformity of PFNA-II® and introduce clinical implications of new cephalomedullary nail (CMN) by analyzing three-dimensional (3D) modeling with virtual implantation at the actual size. Materials and methodsThirty-four patients (average age; 79 years, range 68–94 years) who sustained the intertrochanteric fracture of the femur were enrolled in the present study. After importing into Mimics® software, the intact femurs on the opposite side were selected as cropping areas to reconstruct the 3D femur model with the medullary canal. PFNA-II® and new CMNs (lateral angle 0° and 2°, CCD angle 130°; CMN0° and CMN2°) were processed at the actual size and ideally placed in the proximal femur using Mimics® software. The virtual entry point (EP), nail conformity, and anatomical relationships with the adjacent structures were assessed. ResultsThe virtual EP of PFNA-II® was placed along the cervico-trochanteric (CT) junction in the posterior half around trochanteric fossa and always medial to the tip of greater trochanter (GT). There were six abutments in PFNA-II® models, one impingement in CMN 0°, and no impingement in CMN 2°. All the models with cortical abutment showed increased anterior and lateral bowing of the proximal shaft owing to age-dependent changes. Compared with PFNA-II®, with a decreasing tendency on the mediolateral angle of new CMNs, the virtual EP shifted to the medial and anterior side towards the CT junction. By simulating the intentional positioning in the media-to-lateral direction, the abutments in the PFNA-II® model could not be avoided. Furthermore, the lag screw of CMN 0° was placed ideally at the center or inferior side of the femoral head < 10 mm in any direction without a cortical abutment. ConclusionTo avoid cortical abutment of CMN in the Asian geriatric femur, the virtual EP would be technically placed in the medial to the GT tip, and the implant design should be changed to decrease the mediolateral angle.

Respiration modulates oscillatory neural network activity at rest.

Despite recent advances in understanding how respiration affects neural signalling to influence perception, cognition, and behaviour, it is yet unclear to what extent breathing modulates brain oscillations at rest. We acquired respiration and resting state magnetoencephalography (MEG) data from human participants to investigate if, where, and how respiration cyclically modulates oscillatory amplitudes (2 to 150 Hz). Using measures of phase-amplitude coupling, we show respiration-modulated brain oscillations (RMBOs) across all major frequency bands. Sources of these modulations spanned a widespread network of cortical and subcortical brain areas with distinct spectrotemporal modulation profiles. Globally, delta and gamma band modulations varied with distance to the head centre, with stronger modulations at distal (versus central) cortical sites. Overall, we provide the first comprehensive mapping of RMBOs across the entire brain, highlighting respiration-brain coupling as a fundamental mechanism to shape neural processing within canonical resting state and respiratory control networks (RCNs).

Evaluation of a custom-designed human-robot collaboration control system for dental implant robot.

The purpose of this study is to develop a methodology to better control a human-robot collaboration for robotic dental implant placement. We have designed a human-robot collaborative implant system (HRCDIS) which is based on a zero-force hand-guiding concept and a operational task management workflow that can achieve highly accurate and stable osteotomy drilling based on a surgeon's decision and robotic arm movements during implant surgery. The HRCDIS brings forth the robot arm positions, exact drilling location, direction and performs automatic drilling. The HRCDIS can also avoid complex programing in the robot. The purpose of the study is to evaluate the accuracy of drilling resulting from our developed operational task management method (OTMM). The OTMM can enable the robot to switch, pause, and resume drilling tasks. The force required for hand-guiding in a zero-force control mode of the robot was detected by a 6D force sensor. We compared our force data to those provided by the manufacturer's manual. The study was conducted on a phantom head with a 3D-printed jaw bone to verify the validity of our HRCDIS. We appraised the discrepancies between free-hand drillings and the HRCDIS controlled drillings at apical centre and head centre of the implant and implant angulation to the baseline data from a virtual surgical planning model. The average required force used by hand-guiding to operate the robot with HRCDIS was near 7 Newton which is much less than the manufacturer's specification (30 Newton). The results from our study showed that the average error at implant head was 1.04±0.37mm, 1.56±0.52mm at the implant apex, and deviation of implant angle was 3.74±0.67°. The results from this study validate the merit of the human-robot collaboration control by the HRCDIS. Based on the improved navigation system using HRCDIS, a robotic implant placement can provide seamless drilling with ease, efficiency and accuracy.