Bone Edges Research Articles

Proton range uncertainty caused by synthetic computed tomography generated with deep learning from pelvic magnetic resonance imaging

Background In proton therapy, it is disputed whether synthetic computed tomography (sCT), derived from magnetic resonance imaging (MRI), permits accurate dose calculations. On the one hand, an MRI-only workflow could eliminate errors caused by, e.g., MRI-CT registration. On the other hand, the extra error would be induced due to an sCT generation model. This work investigated the systematic and random model error induced by sCT generation of a widely discussed deep learning model, pix2pix. Material and Methods An open-source image dataset of 19 patients with cancer in the pelvis was employed and split into 10, 5, and 4 for training, testing, and validation of the model, respectively. Proton pencil beams (200 MeV) were simulated on the real CT and generated sCT using the tool for particle simulation (TOPAS). Monte Carlo (MC) dropout was used for error estimation (50 random sCT samples). Systematic and random model errors were investigated for sCT generation and dose calculation on sCT. Results For sCT generation, random model error near the edge of the body (∼200 HU) was higher than that within the body (∼100 HU near the bone edge and <10 HU in soft tissue). The mean absolute error (MAE) was 49 ± 5, 191 ± 23, and 503 ± 70 HU for the whole body, bone, and air in the patient, respectively. Random model errors of the proton range were small (<0.2 mm) for all spots and evenly distributed throughout the proton fields. Systematic errors of the proton range were −1.0(±2.2) mm and 0.4(±0.9)%, respectively, and were unevenly distributed within the proton fields. For 4.5% of the spots, large errors (>5 mm) were found, which may relate to MRI-CT mismatch due to, e.g., registration, MRI distortion anatomical changes, etc. Conclusion The sCT model was shown to be robust, i.e., had a low random model error. However, further investigation to reduce and even predict and manage systematic error is still needed for future MRI-only proton therapy.

Poster 118: False Profile Radiograph Sourcil-Edge and Bone-Edge Measurements Both Correlate to Different Weight-Bearing Regions of the Acetabulum: A Three-Dimensional Analysis

Objectives: The acetabular sourcil has been thought of as the radiographic representation of the weightbearing dome of the acetabulum; however, there are limited modern data to support this supposition. In the literature, assessment of weightbearing acetabular coverage has been described using both the sourcil-edge and bone-edge as anatomic landmarks, leading to confusion and controversy in classification of hip dysplasia, indications for hip preservation surgery, and intraoperative coverage assessment. The purpose of this study was to localize the three-dimensional (3D) anatomic correlates of the sourcil-edge and bone-edge radiographic position on false profile radiographs. The authors hypothesized that the sourcil-edge on the false profile represents anterolateral coverage while the bone-edge represents anterior coverage. Methods: Forty hips were grouped by large or small differences between bone-edge and sourcil-edge anterior center edge angles (ACEA). The small difference group comprised the lowest quartile of sourcil-edge to bone-edge difference of an initial cohort of 80 hips, while the large difference group comprised the highest quartile of difference. 3D surface mesh models and digitally reconstructed radiographs (DRRs) were generated from hip computed tomography scans using the 3D Slicer Image Computing Platform (Figures 1 &amp; 3). Sourcil-edge, bone-edge, and ACEAs were identified on DRRs and registered to the 3D models with fiducial markers. Intersection of bone-edge and sourcil-edge projection lines with the acetabular rim were obtained from the 3D models (Figures 2 &amp; 4). 3D Anterior acetabular rim morphology was correlated with ACEA difference. Results: The bone-edge and sourcil-edge projections intersected the acetabular rim at a mean of 2:08 ± 0:25 and 1:20 ± 0:24 o’clock, respectively. The 3D models consistently demonstrated that, in both large and small discrepancy groups, the sourcil-edge corresponded to an area just posterior to the AIIS projection while the bone-edge corresponded to the weight-bearing region inferior to the AIIS (Figures 2 &amp; 4). Additionally, in large discrepancy hips, the bone-edge corresponded to a more prominent acetabular coverage in the region of the AIIS than when compared to the small discrepancy hips. Conclusions: This study demonstrates that both the sourcil-edge and bone-edge projections on false profile radiographs correlate with differing weightbearing regions of the acetabulum. The sourcil-edge ACEA represents coverage at 1:20 o’clock on the acetabular rim and is consistently posterior to the AIIS, while the bone-edge measurement represents the region of the acetabular rim at 2:08 o’clock and is consistently inferior to the AIIS. In hips with a large discrepancy between bone-edge and sourcil-edge (highest quartile), ACEA measurement differs by a mean of 19.7 degrees based on the selection of these radiographic landmarks. These findings have substantial implications for hip preservation surgery technique and clinical decision making. A comprehensive understanding of femoral head coverage is essential for the treatment of young adult hip pathology. Although the sourcil and bone edge are two of the most important radiographic landmarks for assessment of acetabular dysplasia, descriptions of these landmarks are often over simplified. Some authors have advocated for greater utilization of measurements of coverage to the bone edge as it can be more consistently identified. Other authors have advocated for utilizing the sourcil-edge measurement as this is more representative of the “weight bearing dome”. These descriptions are limited as they do not improve our understanding of the anatomic and radiographic structure of the anterior acetabular rim. Although the concept of the “weight bearing dome” is classically described, it lacks anatomic precision. The present study clarifies the anatomic features of the acetabular rim that correspond to these radiographic features. Increased difference between the sourcil-edge and bone edge is generated by the differences in undulation of the anterosuperior acetabular rim. Acetabuli that have maximal anterior rim prominence at or near the superior-most aspect of the acetabulum (generally counterclockwise from the AIIS) tend to demonstrate smaller discrepancy between the bone-edge and sourcil-edge (Figure 4). Acetabuli that have maximal rim prominence medial and anterior to the superior-most aspect of the acetabulum generally demonstrate larger discrepancy (Figure 2). The present anatomic description can be utilized by the hip arthroscopist to better determine which areas of the anterior rim may cause impingement. Similarly, while conducting a periacetabular osteotomy, the surgeon may use this information to better understand how acetabular rotation is contributing to both anterior and anterolateral coverage. In conclusion, on false profile radiographs, the sourcil-edge corresponds to superior femoral head coverage, while the bone-edge corresponds to anterosuperior coverage. False profile radiographs with a large discrepancy between sourcil-edge and bone-edge measurements demonstrate a prominent weight bearing surface in the region of the AIIS. These data regarding the radiographic phenomena of the acetabular rim can aid in clinical decision-making and intraoperative technique.

Two-stage multi-task deep learning framework for simultaneous pelvic bone segmentation and landmark detection from CT images.

Pelvic bone segmentation and landmark definition from computed tomography (CT) images are prerequisite steps for the preoperative planning of total hip arthroplasty. In clinical applications, the diseased pelvic anatomy usually degrades the accuracies of bone segmentation and landmark detection, leading to improper surgery planning and potential operative complications. This work proposes a two-stage multi-task algorithm to improve the accuracy of pelvic bone segmentation and landmark detection, especially for the diseased cases. The two-stage framework uses a coarse-to-fine strategy which first conducts global-scale bone segmentation and landmark detection and then focuses on the important local region to further refine the accuracy. For the global stage, a dual-task network is designed to share the common features between the segmentation and detection tasks, so that the two tasks mutually reinforce each other's performance. For the local-scale segmentation, an edge-enhanced dual-task network is designed for simultaneous bone segmentation and edge detection, leading to the more accurate delineation of the acetabulum boundary. This method was evaluated via threefold cross-validation based on 81 CT images (including 31 diseased and 50 healthy cases). The first stage achieved DSC scores of 0.94, 0.97, and 0.97 for the sacrum, left and right hips, respectively, and an average distance error of 3.24mm for the bone landmarks. The second stage further improved the DSC of the acetabulum by 5.42%, and this accuracy outperforms the state-of-the-arts (SOTA) methods by 0.63%. Our method also accurately segmented the diseased acetabulum boundaries. The entire workflow took ~ 10s, which was only half of the U-Net run time. Using the multi-task networks and the coarse-to-fine strategy, this method achieved more accurate bone segmentation and landmark detection than the SOTA method, especially for diseased hip images. Our work contributes to accurate and rapid design of acetabular cup prostheses.

A deep learning-based automatic segmentation of zygomatic bones from cone-beam computed tomography images: A proof of concept

ObjectivesTo investigate the efficiency and accuracy of a deep learning-based automatic segmentation method for zygomatic bones from cone-beam computed tomography (CBCT) images. MethodsOne hundred thirty CBCT scans were included and randomly divided into three subsets (training, validation, and test) in a 6:2:2 ratio. A deep learning-based model was developed, and it included a classification network and a segmentation network, where an edge supervision module was added to increase the attention of the edges of zygomatic bones. Attention maps were generated by the Grad-CAM and Guided Grad-CAM algorithms to improve the interpretability of the model. The performance of the model was then compared with that of four dentists on 10 CBCT scans from the test dataset. A p value <0.05 was considered statistically significant. ResultsThe accuracy of the classification network was 99.64%. The Dice coefficient (Dice) of the deep learning-based model for the test dataset was 92.34 ± 2.04%, the average surface distance (ASD) was 0.1 ± 0.15 mm, and the 95% Hausdorff distance (HD) was 0.98 ± 0.42 mm. The model required 17.03 s on average to segment zygomatic bones, whereas this task took 49.3 min for dentists to complete. The Dice score of the model for the 10 CBCT scans was 93.2 ± 1.3%, while that of the dentists was 90.37 ± 3.32%. ConclusionsThe proposed deep learning-based model could segment zygomatic bones with high accuracy and efficiency compared with those of dentists. Clinical significanceThe proposed automatic segmentation model for zygomatic bone could generate an accurate 3D model for the preoperative digital planning of zygoma reconstruction, orbital surgery, zygomatic implant surgery, and orthodontics.

Progress in diagnosis and hip arthroscopic treatment of borderline developmental dysplasia of hip with Cam-type femoroacetabular impingement

To summarize the biomechanical characteristics, diagnosis, and hip arthroscopic treatment of borderline developmental dysplasia of hip (BDDH) with Cam-type femoroacetabular impingement (Cam FAI). The literature on BDDH with Cam FAI at home and abroad in recent years was extensively reviewed and analyzed. In patients with BDDH and Cam FAI, the femoral neck anteversion angle and femoral neck shaft angle increase, the pelvis tilts, and the acetabulum rotates, resulting in instability of the hip joint. In order to maintain the stability of the hip joint, the direction of biomechanical action of the hip joint has changed, which further affects the anatomical structures such as the proximal femur and acetabular morphology. BDDH with Cam FAI can be diagnosed clinically by combining lateral center edge angle, anterior center edge angle, and acetabular index. BDDH with Cam FAI can be effectively treated through arthroscopic polishing of the edges of the acetabular proliferative bone, excision of Cam malformations, and minimally invasive repair of the glenoid lip and cartilage of the hip joint. Currently, there is no unified standard for the diagnosis and treatment of BDDH with Cam FAI. Minimally invasive treatment of the hip under arthroscopy can achieve good early- and medium-term effectiveness, and has certain advantages in repairing and maintaining the integrity of the glenoid lip and suturing/compression joint capsule. However, the long-term effectiveness needs to be further followed up to determine. The timing of surgery, intraoperative bone edge depth polishing, and joint capsule suturing/compression techniques also need to be further explored.

Strontium-containing nanostructured hydroxyapatite microspheres for bone regeneration

The aim of this study was to analyze the biological behavior and osteogenic potential of nanostructured hydroxyapatite microspheres substituted with strontium (nHASr). Therefore, twenty adult male Wistar rats were randomly distributed into two groups: GnHASr – critical bone defect filled with nHASr microspheres; e CG (control group) – critical bone defect without implantation of biomaterial; evaluated at the biological points of 30 and 60 days. The collected specimens were processed and stained with hematoxylin-eosin (HE) and Masson-Goldner trichrome (TG) and examined by light microscopy. Posteriorly, they were analyzed histomorphometrically to measure the percentage of neoformed osteoid matrix (%OM). In both groups studied, at all biological points, deposition of reparative osteoid matrix (OM) was observed near the bone edges; discrete chronic inflammatory response; connective tissue formation and neovascularization in the residual area of the defect. In the GnHASr, in the two evaluated periods, the deposition of OM was also noticed, both around and inside the microspheres. At 60 days, an area of 7.54% of OM deposition in relation to the total defect area was evidenced in the GnHASr, while in the CG this value was 6.80%. It is concluded that the nHASr microspheres evaluated were biocompatible, biodegradable, bioresorbable, bioactive and osteoconductive. In both groups, the formation of neomineralized tissue occurred in a limited way, which indicates that the concentration of metal used in the replacement did not favor greater osteogenic potential for the biomaterial. The evaluated biomaterial it's adequate for use as a filling material.

Quantification of swallowing movements by ultrasound imaging in normal and disordered subjects

Ultrasound imaging may be useful for tracking oral-pharyngeal structures of the vocal tract critical for effective swallowing, but use of this technology has been hampered by a lack of validation against standard clinical measures derived from x-ray video fluoroscopy (Modified Barium Swallow Studies or MBSS). Here, we compare quantitative tracking of hyoid bone and tongue motion from ultrasound imaging and simultaneously measured MBSS from a range of participants with disordered and healthy swallowing behavior. The proximal edge of the hyoid bone in MBSS and ultrasound recordings is tracked using CASM (Computational Analysis of Swallowing Mechanics) software, while tongue motion is tracked using TonguePART software, originally developed for analysis of speech. Hyoid trajectories and velocities measured from synchronized ultrasound and MBSS recordings are compared and standard deviations of differences between the two measurements are evaluated. Tongue motion during swallowing is characterized by analysis of root, dorsum, and blade displacement, velocity, and timingas well as tongue base retraction in the pharynx. Preliminary findings show quantitatively similar patterns in ultrasound and MBSS, suggesting that ultrasound has potential utility as an accessible tool for bedside diagnosis and biofeedback. Characteristic patterns separating normal from healthy swallowing, as well as potential therapeutic targets for biofeedback treatment of dysphagia, will be discussed.

Büyük Subkondral Kistler ile Eşlik Eden Lateral Atlantoaksiyel Osteoartrit: KIBT'de Tesadüfi Rastlanan Olgu

Atlantoaxial osteoarthritis (AAOA) is a unique clinical syndrome that differs from other degenerative disorders. It is a heterogeneous disease associated with the loss of the integrity of the articular cartilage with changes in the underlying bone and cortical edges. One of the biggest clinical challenges with AAOA is making a diagnosis. In dentistry, given the increasing use of cone beam computed tomography (CBCT) to evaluate maxillofacial structures, it is likely that dentists will encounter these lesions on CBCT scans. It is extremely important for dentist to sistematically examine anatomical structures other then teeth during clinical and radiographic evaluation in terms of early diagnosis and to prevent delays in treatment. This article presents the case of AAOA accompanied by a subchondral cysts as a random finding on CBCT.

Endoscopic dacryocystorhinostomy with mucosal anastomosing in chronic dacryocystitis with three categories of ethmoid sinuses.

To evaluate the outcome of endoscopic dacryocystorhinostomy (En-DCR) with mucosal anastomosis in chronic dacryocystitis patients, with various categories of ethmoid sinuses. Between July 2015 and September 2019, 1439 adult patients, representing 1623 affected eyes, presented with chronic dacryocystitis and were scheduled for En-DCR. The categories of ethmoid sinuses were preoperatively determined, using computed tomography-dacryocystography (CT-DCG), and were classified as category 1 (C1), category 2 (C2), and category 3 (C3). No sinuses anterior to the posterior lacrimal crest defined as C1. Sinuses found between the anterior edge of the lacrimal bone and the posterior lacrimal crest defined as C2. Sinuses found anterior to the lacrimal bone suture defined as C3. At the end of surgery, the dacryocyst and nasal mucosa were anastomosed in C1, and the dacryocyst mucosa and anterior ethmoid sinus were anastomosed in C2 and C3 ethmoid sinus patients. The surgical success rate and related complications, in patients with 3 categories of ethmoid cells, were monitored and documented. Postoperative data was obtained for 179 C1 affected eyes, 878 C2 affected eyes, and 432 C3 affected eyes. The overall success rate of En-DCR was 93.0% (1385/1489). Additionally, the success rates were comparable among the different ethmoid categories at 12mo post operation. We demonstrated that the major reason for surgical failure was intranasal ostial closure, due to granulation or scar tissue. En-DCR is a feasible and highly effective primary treatment for chronic dacryocystitis. To ensure surgical success, the surgery protocol must be designed in accordance with the category of ethmoid sinuses present in individual patient.

Potential Metastatic Distance of Lymph Nodes in Different Metastatic Patterns for Nasopharyngeal Carcinoma: Implications for Caudal Border of Elective Nodal Target Volume Delineation

<h3>Purpose/Objective(s)</h3> To investigate the potential metastatic distance of involved lymph nodes (LNs) which can reveal possible pathways of microscopic spread and determine the delineation of caudal border of clinical target volume (CTV) for elective nodal irradiation (ENI) in nasopharyngeal carcinoma (NPC). <h3>Materials/Methods</h3> A total of 1412 patients with pathologically-proven NPC between January 2010 and December 2020 were enrolled. The center points of caudal edge of the most caudally involved LN, lateral process of C1, hyoid bone, cricoid cartilage and cranial edge of sternal manubrium were marked on treatment planning CT scans of each patient. The metastatic distance of the most caudally involved LN, lengths of entire neck, level II, III and IV were determined. Metastatic patterns and their respective metastatic distances covering 95% of patients were analyzed. The metastatic distance covering 95% of patients with LN involvement in lower level is recommended as the caudal border of CTV for patients with involved LN in the upper level. Recommendations in this study were compared with consensus guidelines to propose modifications to caudal border of CTV. <h3>Results</h3> In 1412 patients, lengths of level II, III, IV and II + III ranged widely from 2.9-8.4, 1.6-5.5, 1.2-9.6 and 5.5-12.6 cm, accounting for 21%-62%, 9%-41%, 9%-59% and 41%-91% of the entire neck, respectively. A total of 1933 LNs were delineated, LN metastasis was step by step with 1% skipping rate. Six main metastatic patterns were Level II (498, 25.8%), RPLN + II (801, 41.4%), Level II + III/Va (111, 5.7%), RPLN + Level II + III/Va (327, 16.9%), Level II + III/Va + IV/Vb (58, 3.0%) and RPLN + Level II + III/Va + IV/Vb (119, 6.2%), with significantly different mean metastatic distances. Their maximum distance covering 95% patients were 6.0, 6.3, 8.8, 9.8, 12.8, and 13.7 cm, respectively, based on which, caudal borders for metastatic patterns N0, RPLN, Level II, RPLN + Level II, RPLN + Level II, Level II + III/Va, RPLN + Level II + III/Va were recommended. Compared with current recommendations based on anatomic landmarks, the caudal borders of CTV shifted upward in 175 (99.4%) N0 patients, 88 (98.9%) with metastatic RPLN only and all patients with Level II and RPLN + Level II node involvement by 3.2, 2.9, 6.1, and 5.1 cm. However, 9(15.5%) and 6(5.0%) of patients with level III node involvement had lower recommended caudal borders of ENI than cranial edge of sternal manubrium (Table 1). <h3>Conclusion</h3> Delineation of the caudal border of CTV based on anatomical markers is highly heterogeneous and unstable. This study suggests using the potential metastatic distance (representing the metastatic capacity) of LNs in the lower level as the caudal border of CTV when with involved LN in the upper level. It could reduce the CTV volume in most patients, leading to an expected significant reduction in acute and late toxicity. However, potential metastatic distance in some patients suggests a lower CTV caudal border, indicating the anatomical marker-cased recommendation are insufficient.

A new automatic stitching method for full-length lower limb radiography.

Full-length lower limb x-rays are used to diagnose and plan surgical procedures, such as Total Knee Arthroplasty (TKA) and High Tibial Osteotomy (HTO). Due to the size limitation of digital radiography (DR), panoramic x-ray images cannot be obtained in a single exposure, necessitating multiple exposures and image stitching. In favor of manually constructing full-length x-ray images, we propose a new feature-based automated method for stitching together x-ray images. This new method is based on Canny algorithm, which detects and aligns bone edges before fusing them using a Wavelet form domain. Twenty-eight sets of lower limb x-ray images obtained from our hospital have been stitched and evaluated. The hip, knee, and ankle (HKA) angle was computed in two different ways then compared to manually stitched x-ray images by an expert. The stitching time was only three seconds, and the P-value was P = 0.974, and an accuracy rate of 100% was found. This method demonstrated greater precision and speed than both manually stitched x-ray images and previously published methods.

Automatic Diagnosis of Elbow Arthritis Based on Edge Algorithm

Osteoarthritis is an age-related degenerative joint disease; it is mainly because the cartilage tissue between bones is worn and thinned, which leads to the damage of the periosteum and bone including the surrounding ligaments. Clinically, its manifestations are mainly joint pain, swelling, stiffness, and even partial loss of function, which seriously affects the quality of life of patients. The main clinical manifestations are elbow joint pain and limited movement. Elbow articular cartilage degenerates and falls off, and the more serious manifestation is subchondral hyperosteogeny and sclerosis, which leads to unsmooth articular surface and narrow joint space. Finally, elbow joint pain is severe with different degrees of mobility disorder, elbow joint extension and flexion range is getting smaller and smaller, and elbow joint pain is getting more and more serious. In this paper, the segmentation of left and right elbow images is completed based on gray projection through the analysis of image gray distribution. After obtaining the region of interest of elbow joint, the extraction algorithm of elbow joint hard bone edge is studied. Firstly, the extraction of elbow joint hard bone contour edge is completed based on active shape model algorithm combined with image characteristics. Finally, according to the extraction results of hard bone contour edge, this paper realizes the automatic diagnosis of multiple elbow arthritis indexes and compares with the results given by the image set, which proves that the whole algorithm has good adaptability and accuracy.

Variations anatomiques du sinus ethmoïdal des patients opérés de dacryocystorhinostomie au centre hospitalier Hassan II de FES (étude de 215 patients)

Although several studies have tried to identify the causes of failure of dacryocystorhinostomy (DCR) surgery, the ethmoid sinus remains an underestimated and little described source of failure. To study anatomical relationship between the ethmoidal sinus, particularly the "Agger nasi" cell, with the lacrimal fossa in the North African population, little described in the literature. This study is based on the results of preoperative analysis of dacryo-computed tomography. Analysis of preoperative computed tomography images of patients undergoing dacryocystorhinostomy over a 7-year period from January 2011 to December 2017. Anatomical relationships were studied according to the following classification: type I: No ethmoid cells located anteriorly to the posterior lacrimal crest on transverse images; type II: ethmoidal cells extending anteriorly to the posterior lacrimal crest, but not reaching the anterior edge of the lacrimal bone; Type III: ethmoidal cells located anterior to the lacrimal bone suture. Two hundred and fifteen preoperative computed tomography images were analyzed. The morphology of the ethmoid sinus was classified as type 1 in 33.5%, type 2 in 42.32% and type 3 in 24.18%. Computed tomography analysis was symmetrical in 87.5% and asymmetrical in 12.5%. During dacryocystorhinostomy, the surgeon must take into consideration type III, which can be present in 25% of cases. In the case of surgical failure, a dacryo-CT must be performed to rule out such anterior positioning of the ethmoid cells.

Effect of the manufacturing parameters on the tensile and fracture properties of FDM 3D-printed PLA specimens

Fused Deposition Modeling (FDM), also known as material extrusion, is currently one of the most popular Additive Manufacturing (AM) technology on the market. In this study, two commercial FDM printers (Prusa i3 MK3 and WN400 3D Platform) were used for layer-by-layer manufacturing of polylactic acid (PLA) Dog Bone (DB) and Single Edge Notched Bend (SENB) specimens, aimed at investigating the influence of the manufacturing parameters on the tensile and fracture properties of PLA elements obtained by FDM technology. The effects of growing direction (horizontal and vertical), building orientation (0°, 45° and 90°), printer type, layer thickness (0.15 and 0.40 mm), specimen thickness (4 and 10 mm) and filament color (purple, white, black, gray, red, orange) are discussed in detail. Tensile tests were performed on DB specimens, while fracture mechanics tests on SENB specimens. Both the tensile and fracture properties of FDM 3D-printed PLA specimens have been found to be dependent on the investigated manufacturing parameters. From the microstructural analyses of the SENB fracture surfaces, it has been observed that the fracture mechanisms and crack propagation is a step-wise process. Finally, the material properties charts (Young’s modulus and mode I fracture toughness versus tensile strength) are plotted.

Morphological and functional relationship between the orbital gland and olfaction in Upupa epops (hoopoe) and Bubulcus ibis (cattle egret).

This study used both anatomical and histological techniques to investigate the orbital gland's topographic relationship with the surrounding system, using the hoopoe and cattle egret as biological models. Hoopoe has a spindle-shaped lacrimal gland that is suspended on the lateral edge of the frontal bone, whereas cattle egret has a tiny lacrimal gland that is embedded posteriorly within the periorbital fascia. The hoopoe's lacrimal gland has a single duct that runs parallel to the nasolacrimal duct and opens into the posterior nostril hole. In the cattle egret, the tubule-alveolar secretory components comprise neutral and acid glycosaminoglycan. In addition, the Harderian gland is found in both these species, but their draining ducts differ; the Harderian gland of the hoopoe opens into the anterodorsal to the conjunctival fornix, whereas the Harderian gland of the egret opens anteriorly. In both hoopoe and egret, the secretions of Harderian gland include neutral and acid glycosaminoglycan. The Harderian gland is categorized as type II in hoopoe and type I in cattle egrets. The present results concluded that both orbital glands of two bird species studied play an essential role in eye health, where cleaning and lubrication of the cornea surface. Furthermore, the lacrimal gland's location and secretory features may strengthen the olfactory sensitivity of hoopoe, which relies heavily on scent to locate their food, whereas egret relies heavily on visual cues.

Simultaneous reconstruction of septic composite defects in lower extremities: Combination of fasciocutaneous perforator flap and Masquelet technique.

BackgroundManagement of composite defects with deep infection is a challenge to reconstructive surgeons. This study aimed to demonstrate the versatility, safety, and complications of simultaneous reconstruction of infectious composite defects with fasciocutaneous perforator flap combined with the Masquelet technique.MethodsThis study presents 10 patients in whom a fasciocutaneous perforator flap combined with the Masquelet technique was used to restore soft tissue and bone defects of the lower extremity, and were admitted in two level 1 trauma centers in Shanghai. The first stage included debridement of necrotic bone and infected tissues, implantation of a polymethylmethacrylate cement spacer to cover the void; bridging fixation of the osseous defect using external or internal fixators, and soft-tissue reconstruction with a fasciocutaneous perforator flap. The second stage included cement spacer removal with membrane preservation, refreshing bone edges, and grafting the cavity with bone morphogenetic proteins and autologous iliac bone graft.ResultsThe mean follow-up duration after autologous bone graft was 17.5 months. The average bony defects and average flap dimensions were 7.1 cm and 44.9 cm2, respectively. All flaps survived uneventfully. No recurrence of infection was detected in either the second stage of surgery or follow-up period. The mean duration of bone consolidation was 31.9 weeks. One patient had a 2 cm leg length discrepancy, and one patient had mild foot drop. No residual deformity requiring a secondary procedure occurred.ConclusionFasciocutaneous perforator flap combined with Masquelet technique provides a reliable and versatile alternative for patients with composite defects resulting from lower extremity infection.

Inter-Slice Resolution Improvement Using Convolutional Neural Network with Orbital Bone Edge-Aware in Facial CT Images.

The 3D modeling of orbital bones in facial CT images is essential to provide a customized implant for reconstructions of orbit and related structures during surgery. However, 3D models of the orbital bone show an aliasing effect and disconnected thin bone in the inter-slice direction because the slice thickness is two to three times larger than the pixel spacing. To improve the inter-slice resolution of facial CT images, we propose a method based on a 2D convolutional neural network (CNN) that uses the spatial information on the sagittal and axial planes and the orbital bone edge-aware (OBE) loss. First, intermediate slices are generated on the sagittal plane. Second, the generated intermediate slices are transformed to an axial image, which is then compared with the original axial image. To generate intermediate slices with an accurate orbital bone structure, the OBE loss considering the orbital bone structure on the sagittal and axial planes is used. To improve the perceptual quality of the generated intermediate slices, the feature map difference loss is additionally used on the axial plane. In the experiment, the proposed method showed the best performance among bilinear and bicubic interpolations, 3D SRGAN, and a 2D CNN-based method. Experimental results confirmed that the proposed method can generate intermediate slices with clear edges of thin bones as well as cortical bones on both the sagittal and the axial plane.

Optimizing Volar Tilt Restoration and Plate Position in Distal Radius Fractures

Distal radius fractures are common and often treated surgically with a volar plate. A complication of volar plating includes tendonitis or rupture of the flexor pollicis longus (FPL) tendon. We hypothesize that failure to restore the volar tilt of the distal radius results in increased pressure on the FPL tendon. Ten fresh-frozen cadaveric wrists were assessed for this study. During testing, weights were suspended from the FPL tendon to stimulate muscle contraction. Reproducible fractures were created and fixed via volar plating. The contact force between FPL and the bone or plate edge was measured with a force transducer in 5 surgical conditions. These were assessed to evaluate whether failure to restore the volar tilt increases the pressure with a plate proximal or distal to the watershed line. Significant increases in contact forces were observed between the control and both conditions in which volar tilt was not restored, with mean increases of 1.9 N and 3.0 N. A significant increase in the contact force was found when placing the plate distal to the watershed line with a mean increase of 2.03 N comparing the failure to restore volar tilt and after restoring the volar tilt. Significant increases in contact force were also observed between the dorsal plate condition, which failed to restore the volar tilt, and both plate conditions with placement distal to the watershed line, with mean differences of 0.94 N and 1.09 N, respectively. Failure to restore the volar tilt in surgically treated distal radius fractures causes increased pressure on the FPL tendon. Plate placement distal to the watershed line also causes increased FPL tendon pressure over the plate edge. This study demonstrates the importance of restoring the volar tilt of the distal radius in surgically treated distal radius fractures and confirms that plate placement distal to the watershed line will increase pressure on the FPL tendon.

Impact of computed tomography metal artifact reduction protocol on periprosthetic tissue characterization after total hip arthroplasty:A cadaveric study.

Metal artifact reduction (MAR) has improved computed tomography (CT) imaging of total hip arthroplasty (THA) but the assessment of osteolysis and implant to bone contact relies on the accurate depiction of bone defects, cancellous bone, and cement. This study evaluates the impact of available single and dual-energy protocols on periprosthetic tissue characterization in a cadaveric phantom. Bilateral THA was performed on a fresh frozen cadaveric pelvis with simulated osteolytic cavities. CT acquisitions with projection-basedMAR and noise equivalence were performed using single energy 140 kVp, single energy 150 kVp with 0.6 mm tin filtration, and dual-energy at 100/150 kVp with 0.6 mm tin filtration, from which simulated energies were extracted. Image subtraction, segmentation, region of interest histograms, and line profiles were used to characterize tissue density and separation. Tissue densities were heavily dependent on the energy profile of the protocol. Cancellous bone ranged from 182to 45 HU and cement from 1012to 131 HU using 140 kVp compared to dual-energy with weighted high energy tube, respectively. Spectral separation between cancellous bone, osteolytic defect, and cement was reduced for all protocols compared with 140 kVp. Spectral overlap was most severe using dual-energy with heavily weighted high-energy tubes. Dual-energy algorithms reduced trabecular contrast within the cancellous bone and cortical edge response. Althoughthe dual-energy acquisition has been proposed as an additive to projection-based MAR techniques in THA, reduced density and contrast in clinically relevant periprosthetic tissue compared to 140 kVp single energy may limit its use in characterizing periprosthetic tissues.

Automatizing Bone Surface Mapping in 3D Reconstructed Tomographies

Introduction: In orthopedic surgery, having the bone in it’s exactly position is the most important factor for success. In comminuted fractures there is no bone edge to fit, surgeon’s ability becomes fundamental and human error is common. The way to diminish the human factor is to provide anatomically contoured implants so they can be guides for the surgeon. To make these implants it is necessary to compare the 3D bone contour in the population and find the most fitable implant. Materials and Methods: Twenty ankle tomographies were selected and 3D reconstructed for this research. We design and tested a software for semiautomatized bone superficial scanning. The software marked points on bone surface and constructed a spreadsheet with the 3D cartographic reference for each point. Results: The software was able to set the points in bone surface and the reconstruction of the original bone from the spreadsheet was successful. We were not able to reconstruct an average ankle from the averages of the points. Conclusion: Despite the transformation of the 3D bone surface in its numeric presentation was successful, we were still not able to compare individuals. We believe that volumetric paring could be a solution.