An automatic facial landmarking for children with rare diseases.

Two to three thousand syndromes modify facial features: their screening requires the eye of an expert in dysmorphology. A widely used tool in shape characterization is geometric morphometrics based on landmarks, which are precise and reproducible anatomical points. Landmark positioning is user dependent and time consuming. Many automatic landmarking tools are currently available but do not work for children, because they have mainly been trained using photographic databases of healthy adults. Here, we developed a method for building an automatic landmarking pipeline for frontal and lateral facial photographs as well as photographs of external ears. We evaluated the algorithm on patients diagnosed with Treacher Collins (TC) syndrome as it is the most frequent mandibulofacial dysostosis in humans and is clinically recognizable although highly variable in severity. We extracted photographs from the photographic database of the maxillofacial surgery and plastic surgery department of Hôpital Necker-Enfants Malades in Paris, France with the diagnosis of TC syndrome. The control group was built from children admitted for craniofacial trauma or skin lesions. After testing two methods of object detection by bounding boxes, a Haar Cascade-based tool and a Faster Region-based Convolutional Neural Network (Faster R-CNN)-based tool, we evaluated three different automatic annotation algorithms: the patch-based active appearance model (AAM), the holistic AAM, and the constrained local model (CLM). The final error corresponding to the distance between the points placed by automatic annotation and those placed by manual annotation was reported. We included, respectively, 1664, 2044, and 1375 manually annotated frontal, profile, and ear photographs. Object recognition was optimized with the Faster R-CNN-based detector. The best annotation model was the patch-based AAM (p < 0.001 for frontal faces, p = 0.082 for profile faces and p < 0.001 for ears). This automatic annotation model resulted in the same classification performance as manually annotated data. Pretraining on public photographs did not improve the performance of the model. We defined a pipeline to create automatic annotation models adapted to faces with congenital anomalies, an essential prerequisite for research in dysmorphology.

[Automatic determination of mandibular landmarks based on three-dimensional mandibular average model].

OBJECTIVE: To explore an efficient and automatic method for determining the anatomical landmarks of three-dimensional(3D) mandibular data, and to preliminarily evaluate the performance of the method. METHODS: The CT data of 40 patients with normal craniofacial morphology were collected (among them, 30 cases were used to establish the 3D mandibular average model, and 10 cases were used as test datasets to validate the performance of this method in determining the mandibular landmarks), and the 3D mandibular data were reconstructed in Mimics software. Among the 40 cases of mandibular data after the 3D reconstruction, 30 cases that were more similar to the mean value of Chinese mandibular features were selected, and the size of the mandibular data of 30 cases was normalized based on the Procrustes analysis algorithm in MATLAB software. Then, in the Geomagic Wrap software, the 3D mandibular average shape model of the above 30 mandibular data was constructed. Through symmetry processing, curvature sampling, index marking and other processing procedures, a 3D mandible structured template with 18 996 semi-landmarks and 19 indexed mandibular anatomical landmarks were constructed. The open source non-rigid registration algorithm program Meshmonk was used to match the 3D mandible template constructed above with the tested patient's 3D mandible data through non-rigid deformation, and 19 anatomical landmark positions of the patient's 3D mandible data were obtained. The accuracy of the research method was evaluated by comparing the distance error of the landmarks manually marked by stomatological experts with the landmarks marked by the method of this research. RESULTS: The method of this study was applied to the data of 10 patients with normal mandibular morphology. The average distance error of 19 landmarks was 1.42 mm, of which the minimum errors were the apex of the coracoid process [right: (1.01±0.44) mm; left: (0.56±0.14) mm] and maximum errors were the anterior edge of the lowest point of anterior ramus [right: (2.52±0.95) mm; left: (2.57±1.10) mm], the average distance error of the midline landmarks was (1.15±0.60) mm, and the average distance error of the bilateral landmarks was (1.51±0.67) mm. CONCLUSION: The automatic determination method of 3D mandibular anatomical landmarks based on 3D mandibular average shape model and non-rigid registration algorithm established in this study can effectively improve the efficiency of automatic labeling of 3D mandibular data features. The automatic determination of anatomical landmarks can basically meet the needs of oral clinical applications, and the labeling effect of deformed mandible data needs to be further tested.

Comparing semi-landmarking approaches for analyzing three-dimensional cranial morphology.

OBJECTIVES: Increased use of three-dimensional (3D) imaging data has led to a need for methods capable of capturing rich shape descriptions. Semi-landmarks have been demonstrated to increase shape information but placement in 3D can be time consuming, computationally expensive, or may introduce artifacts. This study implements and compares three strategies to more densely sample a 3D image surface. MATERIALS AND METHODS: Three dense sampling strategies: patch, patch-thin-plate spline (TPS), and pseudo-landmark sampling, are implemented to analyze skulls from three species of great apes. To evaluate the shape information added by each strategy, the semi or pseudo-landmarks are used to estimate a transform between an individual and the population average template. The average mean root squared error between the transformed mesh and the template is used to quantify the success of the transform. RESULTS: The landmark sets generated by each method result in estimates of the template that on average were comparable or exceeded the accuracy of using manual landmarks alone. The patch method demonstrates the most sensitivity to noise and missing data, resulting in outliers with large deviations in the mean shape estimates. Patch-TPS and pseudo-landmarking provide more robust performance in the presence of noise and variability in the dataset. CONCLUSIONS: Each landmarking strategy was capable of producing shape estimations of the population average templates that were generally comparable to manual landmarks alone while greatly increasing the density of the shape information. This study highlights the potential trade-offs between correspondence of the semi-landmark points, consistent point spacing, sample coverage, repeatability, and computational time.

Gorilla calcaneal morphological variation and ecological divergence.

OBJECTIVES: The primate foot has been extensively investigated because of its role in weight-bearing; however, the calcaneus has been relatively understudied. Here we examine entire gorilla calcaneal external shape to understand its relationship with locomotor behavior. MATERIALS AND METHODS: Calcanei of Gorilla gorilla gorilla (n = 43), Gorilla beringei graueri (n = 20), and Gorilla beringei beringei (n = 15) were surface or micro-CT scanned. External shape was analyzed through a three-dimensional geometric morphometric sliding semilandmark analysis. Semilandmarks were slid relative to an updated Procrustes average in order to minimize the bending energy of the thin plate spline interpolation function. Shape variation was summarized using principal components analysis of shape coordinates. Procrustes distances between taxa averages were calculated and resampling statistics run to test pairwise differences. Linear measures were collected and regressed against estimated body mass. RESULTS: All three taxa exhibit statistically different morphologies (p < .001 for pairwise comparisons). G. g. gorilla demonstrates an anteroposteriorly elongated calcaneus with a deeper cuboid pivot region and mediolaterally flatter posterior talar facet. G. b. beringei possesses the flattest cuboid and most medially-angled posterior talar facets. G. b. graueri demonstrates intermediate articular facet morphology, a medially-angled tuberosity, and an elongated peroneal trochlea. DISCUSSION: Articular facet differences separate gorillas along a locomotor gradient. G. g. gorilla is adapted for arboreality with greater joint mobility, while G. b. beringei is adapted for more stereotypical loads associated with terrestriality. G. b. graueri's unique posterolateral morphology may be due to a secondary transition to greater arboreality from a more terrestrial ancestor.

Three-dimensional surface scanning methods in osteology: A topographical and geometric morphometric comparison.

OBJECTIVES: Three-dimensional (3D) data collected by structured light scanners, photogrammetry, and computed tomography (CT) scans are increasingly combined in joint analyses, even though the scanning techniques and reconstruction software differ considerably. The aim of the present study was to compare the quality and accuracy of surface models and landmark data obtained from modern clinical CT scanning, 3D structured light scanner, photogrammetry, and MicroScribe digitizer. MATERIAL AND METHODS: We tested 13 different photogrammetric software tools and compared surface models obtained by different methods for four articulated human pelves in a topographical analysis. We also measured a set of 219 landmarks and semilandmarks twice on every surface as well as directly on the dry bones with a MicroScribe digitizer. RESULTS: Only one photogrammetric software package yielded surface models of the complete pelves that could be used for further analysis. Despite the complex pelvic anatomy, all three methods (CT scanning, 3D structured light scanning, photogrammetry) yielded similar surface representations with average deviations among the surface models between 100 and 200 µm. A geometric morphometric analysis of the measured landmarks showed that the different scanning methods yielded similar shape variables, but data acquisition via MicroScribe digitizer was most prone to error. DISCUSSION: We demonstrated that three-dimensional models obtained by different methods can be combined in a single analysis. Photogrammetry proved to be a cheap, quick, and accurate method to generate 3D surface models at useful resolutions, but photogrammetry software packages differ enormously in quality.

Mandibular symphyseal fusion in fossil primates: Insights from correlated patterns of jaw shape and masticatory function in living primates.

OBJECTIVES: Variation in primate masticatory form and function has been extensively researched through both morphological and experimental studies. As a result, symphyseal fusion in different primate clades has been linked to either the recruitment of vertically directed balancing-side muscle force, the timing and recruitment of transversely directed forces, or both. This study investigates the relationship between jaw muscle activity patterns and morphology in extant primates to make inferences about masticatory function in extinct primates, with implications for understanding the evolution of symphyseal fusion. MATERIALS AND METHODS: Three-dimensional mandibular landmark data were collected for 31 extant primates and nine fossil anthropoids and subfossil lemur species. Published electromyography (EMG) data were available for nine of the extant primate species. Partial least squares analysis and phylogenetic partial least squares analysis were used to identify relationships between EMG and jaw shape data and evaluate variation in jaw morphology. RESULTS: Primates with partial and complete symphyseal fusion exhibit shape-function patterns associated with the wishboning motor pattern and loading regime, in contrast to shape-function patterns of primates with unfused jaws. All fossil primates examined (except Apidium) exhibit jaw morphologies suggestive of the wishboning motor pattern demonstrated in living anthropoids and indriids. DISCUSSION: Partial fusion in Catopithecus, similar to indriids and some subfossil lemurs, may be sufficient to resist, or transfer, some amounts of transversely directed balancing-side muscle force at the symphysis, representing a transition to greater reliance on transverse jaw movement during mastication. Furthermore, possible functional convergences in physiological patterns during chewing (i.e., Archaeolemur) are identified.

Assessing the reliability of virtual reconstruction of mandibles.

OBJECTIVES: Mandibular morphological variation is often used to examine various aspects of human palaeobiology. However, fossil and archeological skeletal remains are often fragmented/distorted and so are frequently excluded from studies. This leads to decreased sample sizes and, potentially, to biased results. Thus, it is of interest to restore the original anatomy of incomplete/distorted specimens. Thin plate splines (TPS), commonly used in Geometric Morphometrics (GM), offer the prospect of reconstruction of missing parts and particularly of interest here, missing landmarks. MATERIALS AND METHODS: Here, the reliability of TPS based mandibular reconstruction is tested. To that end missing landmarks were simulated in originally complete hemimandibles. TPS was then used to restore the location of simulated missing data and the predicted landmarks were compared to the original ones. RESULTS: Results show that error varies according to the number and location of estimated landmarks. Notwithstanding, estimation error is usually considerably smaller than the morphological differences between individuals from the same species. DISCUSSION: TPS based reconstruction allows fragmentary mandibles to be used in studies of whole mandibular variation, provided the above mentioned caveats are considered.

Sexual dimorphism of the relationship between the gut and pelvis in humans.

OBJECTIVES: Obstetric demands have long been considered in the evolution of the pelvis, yet consideration of the interaction of pregnancy, the pelvis, and the gastrointestinal tract (gut) is lacking. Here, we explore sex differences in the relationship of gut volume with body size and pelvic dimensions. MATERIALS AND METHODS: Computed tomography (CT) scans of living adult Homo sapiens (46 females and 42 males) were obtained to measure in vivo gut volume (GV) and to extract 3D models of the pelvis. We collected 19 3D landmarks from each pelvis model to acquire pelvic measurements. We used ordinary least squares regression to explore relationships between GV and body weight, stature, and linear pelvic dimensions. RESULTS: The gut-pelvis relationship differs between males and females. Females do not exhibit significant statistical correlations between GV and any variable tested. GV correlates with body size and pelvic outlet size in males. GV scales with negative allometry relative to body weight, stature, maximum bi-iliac breadth, inferior transverse outlet breadth, and bispinous distance in males. DISCUSSION: The lack of association between GV and body size in females may be due to limits imposed by the anticipation of accommodating a gravid uterus and/or the increased plasticity of the pelvis. The pattern of relationship between GV and the pelvic outlet suggests the role of the bony pelvis in supporting the adominal viscera in females may be small relative to its role in childbirth. We conclude that gut size inference in fossil hominins from skeletal proxies is limited and confounded by sexual dimorphism.

The Retropancreatic Fusion Fascia Oriented Splenic Hilar Lymphadenectomy Versus Laparoscopic Approach In D2 Total Gastrectomy.

BACKGROUND The retropancreatic fusion fascia is recognized as the anatomical landmark during retropancreatic mobilization. However, its role in D2 total gastrectomy for proximal advanced gastric cancer (PAGC) remains unexplored. This study aimed to develop the retropancreatic fusion fascia-oriented ex vivo approach for splenic hilar lymphadenectomy (RP-SL) to avoid difficulty in using the total laparoscopic approach (TL-SL). MATERIAL AND METHODS The data for patients with PAGC who underwent D2 total gastrectomy were retrieved from our clinical database and electronic medical records (December 2016 to December 2018), with a 1:1 match ratio for balance of the 2 groups. RESULTS In sum, 84 matched patients were included in the study. There were 2360 retrieved lymph nodes (LNs), with an average of 28.10. Sixteen patients were confirmed with positive splenic hilar lymphadenectomy, and the mean harvested lymph nodes (LNs) were significantly increased in the RP-SL group compared to the TL-SL group (3.07 vs. 2.29, P<0.001), decreased operative time (193.21 min vs. 247.74 min, P<0.001), and less blood loss (96.90 mL vs. 185.24 mL, P=0.001) in the RP-SL group. Postoperative hospital stay (6.55 days vs. 7.26 days), rate of morbidity (9.50% vs. 11.91%), and overall costs (¥65255.64 vs. ¥64419.91) were comparable between the groups (P>0.05).  CONCLUSIONS The landmark at the conjunction between the superior mesenteric vessels and the inferior pancreatic margin made it feasible to identify the retropancreatic areolar. The RP-SL approach was safe and efficient for splenic hilar lymphadenectomy.

Ros-NET: A deep convolutional neural network for automatic identification of rosacea lesions.

BACKGROUND: Rosacea is one of the most common cutaneous disorder characterized primarily by facial flushing, erythema, papules, pustules, telangiectases, and nasal swelling. Diagnosis of rosacea is principally done by a physical examination and a consistent patient history. However, qualitative human assessment is often subjective and suffers from a relatively high intra- and inter-observer variability in evaluating patient outcomes. MATERIALS AND METHODS: To overcome these problems, we propose a quantitative and reproducible computer-aided diagnosis system, Ros-NET, which integrates information from different image scales and resolutions in order to identify rosacea lesions. This involves adaption of Inception-ResNet-v2 and ResNet-101 to extract rosacea features from facial images. Additionally, we propose to refine the detection results by means of facial-landmarks-based zones (ie, anthropometric landmarks) as regions of interest (ROI), which focus on typical areas of rosacea occurrence on a face. RESULTS: Using a leave-one-patient-out cross-validation scheme, the weighted average Dice coefficients, in percentages, across all patients (N = 41) with 256 × 256 image patches are 89.8 ± 2.6% and 87.8 ± 2.4% with Inception-ResNet-v2 and ResNet-101, respectively. CONCLUSION: The findings from this study support that pre-trained networks trained via transfer learning can be beneficial in identifying rosacea lesions. Our future work will involve expanding the work to a larger database of cases with varying degrees of disease characteristics.

The Distance between the Pylorus and Left Vagus Nerve during Sleeve Gastrectomy.

The sleeve gastrectomy (SG) can be performed with or without antral preservation (distance from the pylorus <50 mm). The objective of this study was to evaluate the distance between the pylorus and the end of the left vagus nerve in order to determine whether it could be used as a constant anatomical landmark to start gastric transection. This was a prospective, nonrandomized study of 120 patients undergoing SG from January to October 2018. The distance measurement between pylorus and vagus nerve was performed at the beginning of the SG. The primary endpoint was the distance between the beginning of the pylorus and the end of the second branch of the vagus nerve on the upper edge of the antrum. The secondary endpoints was the correlation factors between the preoperative data and the position of the end of the vagus nerve. A total of 120 patients, with a mean body mass index of 42.2 kg/m2 , underwent primary SG. The mean distance between pylorus and the end of the vagus nerve was 50.4 mm (35-64) on the upper part of the antrum. When considering the inferior part of the antrum, the minimum distance was 50 mm. No correlations were found between preoperative data and distance measurements. The vagus nerve can be considered as a constant and reliable anatomical landmark for performing SG with antral preservation. However, no correlation was found between the preoperative data and the location of the end of the vagus nerve. Clin. Anat. 33:562-566, 2020. © 2019 Wiley Periodicals, Inc.

Spinal dural sac termination and internal filum terminale fusion: A Study from 80 Cadavers.

Surgery for tethered spinal cord caused by thickened filum terminale (FT) is frequently performed through S1 laminectomy based on the assumption that the internal FT (FTi) fuses with dura mater at S2 vertebral level. Literature on specific study for the site of its fusion and dural sac (DS) termination was rather limited. Moreover, there is no large anatomical study in Asian population. To determine the anatomy, examination of the FTi fusion site, as well as the region at which DS ended, was undertaken. From 80 embalmed cadavers, the majority of FTi fusion occurred at, or below, S1/S2 disk space (62.5%) which was less frequent than previous reports (70%-90%). In addition, there was 11.3% of the fila that fused above S1. Regarding the DS termination, it was found at, or below, S1/S2 disk space in 76.3% with one subject (1.3%) at L5/S1 disk space. With modest differences compared with non-Asian cadaveric data, our results offer pertinent information to surgeons performing tethered cord release. One ought to keep in mind that small, but not negligible, percentage of FTi can fuse with dura mater above S1 level; hence, more rostral laminectomy at L5 may be required. Clin. Anat. 33:558-561, 2020. © 2019 Wiley Periodicals, Inc.

Anatomical evaluation of the craniovertebral junction on cone-beam computed tomography images.

INTRODUCTION: There are many craniometric measurements that are used in evaluating craniovertebral junction (CVJ) pathologies such as basilar invagination, atlantoaxial dislocation and platybasia. Therefore, it is important to determine the normal reference range of the craniometric measurements. This study aims to determine the morphometric reference values of the bony structures in the CVJ from cone-beam computed tomography (CBCT) images of a group of South Eastern Anatolian population. MATERIALS AND METHODS: The CBCT images of 300 individuals were retrospectively evaluated. 14 parameters on midsagittal and 2 parameters on the coronal plane were studied. The data were statistically evaluated. RESULTS: Measurement results were found as follows; the distances between odontoid process (OP) and McGregor line as 0.31 ± 3.22 mm, OP and Chamberlain line 1.06 ± 3.22 mm, OP and McRae line 5.30 ± 1.59 mm, OP and Fischgold digastric line 8.70 ± 4.12 mm, OP and Fischgold bimastoid line - 5.15 ± 4.86 mm, length of McRae line 35.58 ± 2.52 mm, atlantodental interval 1.28 ± 0.48 mm, posterior atlantodental interval 19.54 ± 2.24 mm, basion axial interval 4.01 ± 1.83 mm, basion dental interval 4.92 ± 1.77 mm, length of Modified Ranawat line 28.66 ± 2.38 mm, length of Redlund-Johnell line 35.11 ± 4.09 mm, clivus canal angle 157.62° ± 11.85°, Welcher basal angle 130.83° ± 6.29°, craniocervical tilt 126.98° ± 12.24° and Powers ratio as 0.72 ± 0.06. CONCLUSION: In this study, the morphometric values were evaluated according to age and gender in individuals who did not have any radiologic anomalies. The normal reference ranges may be useful for researchers who are researching pathology in this region. It is recommended to conduct further studies with different populations to determine the normal reference range.

Developing an international standard for the classification of surface anatomic location for use in clinical practice and epidemiologic research.

BACKGROUND: There is currently no universally adopted terminology for defining human surface anatomic location. The lack of precision, accuracy, and reliability of terms used by health care providers, in particular dermatologic surgeons, is unsatisfactory both for epidemiologic research and for high-quality patient care. OBJECTIVE: We sought to create a clinically relevant yet concise surface anatomy terminology for international use including the International Classification of Diseases and to map it to existing disparate terminologies. METHODS: Widely used surface anatomy terminology data sets and diagrams were reviewed. A Delphi consensus convened to create a novel surface anatomy terminology. The new terminology was hierarchically mapped to Systematized Nomenclature of Medicine terms and New York University numbers and physically mapped to 2-dimensional anatomic diagrams for clarity and reproducibility. RESULTS: The final terminology data set contains 519 discrete terms arranged in a 9-level hierarchy and has been adopted by the World Health Organization for the International Classification of Diseases, 11th revision. LIMITATIONS: Specification of most locations requires linking to laterality qualifiers. Fine granularity for larger sites may require the use of additional qualifiers. CONCLUSION: Consistent use of precise and accurate surface anatomy terms is crucial to the practice of dermatology, particularly procedural dermatology. The proposed terminology is designed to form the basis for evolution of a universally adoptable terminology set to improve patient care, interprovider communication, and epidemiologic tracking.

Testing landmark redundancy for sex-based shape analysis of the adult human os coxa.

OBJECTIVES: To test the individual effectiveness of common landmarks used in sex estimation of whole adult coxal bones in sex-based shape analysis and propose a method to determine how many principal components of sex-based shape to include for discriminant function analysis. METHODS: Three-dimensional models (NextEngine desktop laser scanner) of left and right os coxae from 396 individuals (William Bass Skeletal Collection, Forensic Anthropology Centre, University of Tennessee, Knoxville, TN) were subjected to shape analysis using 32 landmarks (Landmark 3.6, Institute for Data Analysis and Visualization). Each landmark was individually removed and subjected to a new principal component analysis to identify the effect omitting a landmark has on PC1/PC2 ordination. Landmarks that poorly discriminated sex-based shape were considered redundant for analysis on sex estimation. RESULTS: This study identified 17 landmarks that represent sex-based shape of right and left coxal bones most effectively, these are: the anterior superior iliac spine; posterior superior iliac spine; posterior inferior iliac spine; iliac crest; apex of the auricular surface; greater sciatic notch; ischial spine; superior, inferior and distal points on ischial tuberosity; superior, inferior and midpoint on the symphyseal face; arcuate eminence; ischiopubic ramus; posterosuperior and anterosuperior points on the acetabular rim. The first and second PCs of the 17-landmark configuration correctly predicted sex in 98.5% of cases; better than a 32-landmark configuration (96%) and better than previous landmark studies on whole coxal bone sex-based shape. CONCLUSIONS: These 17 landmarks represent more meaningful data for sex-based shape analysis in PC1 and 2 and concentrate meaningful sex-based shape data to the first five PCs that make up over 50% of the total shape variance.

Characterization of an anatomic safe zone surrounding the lower subscapular nerve during an open deltopectoral approach.

BACKGROUND: Due to anatomic variance in subscapular nerve innervation patterns, it is theorized that the dysfunction of the subscapularis could be the result of iatrogenic denervation during mobilization of the subscapularis while exposing the anterior glenohumeral joint in anterior surgical approaches. The purpose of this study was to describe innervation patterns of the subscapularis and to characterize a safe zone when conducting an anterior surgical approach. METHODS: The study used 6 human cadaveric shoulder specimens (12 shoulders total). A deltopectoral approach was used to expose the axillary nerve back to the posterior cord of the brachial plexus and reveal the origins of the upper and lower subscapularis nerves. An anatomic safe zone was characterized by measuring distances from both the upper and lower subscapularis nerve insertions with respect to that of the lateral border of the conjoint tendon, the bicipital groove, superior border of the subscapularis, and the axillary nerve (for the lower subscapular nerve only) with the arm in 30° abduction. RESULTS: The anatomic safe zone of the subscapular nerves medial to the conjoint tendon is less than 32 mm. In relation to the axillary nerve, the safe zone is less than 10 mm inferiorly and 15 mm medially. CONCLUSIONS: This described safe zone with respect to the lateral border of the conjoint tendon and axillary nerve is aimed to provide guidance to reduce iatrogenic injury of the subscapular nerves during anterior shoulder exposure. Extra care should be undertaken while dissecting past this safe zone to prevent iatrogenic subscapular nerve injury.

The lateral collateral ligament complex of the elbow: quantitative anatomic analysis of the lateral ulnar collateral, radial collateral, and annular ligaments.

BACKGROUND: Injury to the lateral ulnar collateral ligament (LUCL) complex of the elbow often results in posterolateral rotatory instability. Although surgical reconstruction of the LUCL is often required, gaps in our understanding of the LUCL complex remain. The purpose of this study was to provide a robust and accurate characterization of the lateral elbow ligamentous complex. METHODS: The LUCLs, radial collateral ligaments, and annular ligaments in 10 cadaveric elbows were 3-dimensionally digitized and reconstructed using computed tomography. Surface areas, origin and insertion footprint areas, distances between perceived footprint centers and geometric footprint centroids, distances to key landmarks, and ligament isometry were measured. RESULTS: The mean surface area of the LUCL was 229.3 mm2. The mean origin and insertion footprint areas were 26.0 mm2 and 22.9 mm2, respectively. The mean distance between the apparent centers and the geometric centroids of the footprints was 1 mm. The center of the LUCL origin was 10.7 mm distal to the lateral epicondyle and 8.2 mm from the capitellar articular margin. The center of the LUCL insertion was 3.3 mm distal to the apex of the supinator crest. The LUCL showed anisometric properties as elbow flexion increased (P < .001). CONCLUSIONS: The LUCL origin center was 10.7 mm from the lateral epicondyle, whereas the insertion center was 3.3 mm from the apex of the supinator crest. The visually estimated footprint centers were generally within 1 mm of the geometric centroid. These geometries and distances to key landmarks will be informative for surgeons seeking to perform anatomic ligament reconstruction procedures.

Pediatric central venous catheterization: The Role of the Aortic Valve in Defining the Superior Vena Cava-Right Atrium Junction.

The aortic valve (AV) has been used as a surrogate marker for the superior vena cava-right atrium (SVC-RA) junction during the placement of central venous catheters. There is a paucity of evidence to determine whether this is a consistent finding in children. Eighty-seven computed tomography scans of the thorax acquired at local children's hospitals from April 2010 to September 2011 were retrospectively collected. The distance between the SVC-RA junction and the AV was measured by dual consensus. The cranio-caudal level of the junction and the AV were referenced to the costal cartilages (CCs) and anterior intercostal spaces (ICSs). The results confirmed that the SVC-RA junction has a variable relationship to the AV. The junction was on average 3.1 mm superior to the AV. This distance increased with age. In the <1-year-old age group, the junction was on average 1.3 mm superior to the AV (range: -6 to 11 mm). In the 1-2 years old age group: 3.5 mm (range: -8 to 15 mm). In the 3-6 years old: 3.8 mm (range: -9 to 13 mm). In the >7 years old age group: 4 mm (range: -11 to 16 mm). The surface anatomy of the SVC-RA junction was variable, ranging from the second ICS to sixth CC. The SVC-RA junction has a predictable relationship to the AV, and this can be used as an adjunct marker for accurate placement of central venous catheters except in the smallest neonates. Clin. Anat. 32:778-782, 2019. © 2019 Wiley Periodicals, Inc.

Three-dimensional cephalometric analysis of the maxilla: Analysis of new landmarks.

INTRODUCTION: Clinical evaluation of the midface including the paranasal and upper lip regions is highly subjective and complex. Traditional and 3-dimensional cephalometrics were not developed with the clinical appearance of these midfacial areas in mind and are therefore inappropriate surrogates for the clinical appearance of the midface, making them unsuitable as aids in diagnosing dentofacial deformities. The aim of this study was to evaluate traditional as well as newly defined landmarks and measurements and their correlation with clinical appearance of the midface. METHODS: Fifty-two subjects who underwent full-field cone-beam computed tomography were recruited for this study. A single examiner assessed each subject's midfacial region (paranasal and upper lip), and a second examiner obtained traditional and newly defined cephalometric measurements for each subject. Both examiners were blinded to each other's data throughout the study. Statistical analysis was performed to assess the correlations of the traditional and novel cephalometric measurements with clinical midfacial findings. The impact of the soft tissue thickness in the paranasal region was also analyzed. The performance of any classification derived from statistically significant variables was analyzed with the use of micro-F scores and area under the receiver operating characteristic curve (AUC). RESULTS: Both traditional (SNA) and newly defined measurements (SNANS, SNPR, SNNP, SNh) had no statistically significant correlation with clinical paranasal diagnosis. However, in the absence of upper lip procumbency or protrusion, SNNP and SNh had statistically significant correlations with clinical paranasal diagnosis (P = 0.047 and P = 0.003, respectively). For upper lip analysis, both traditional (SNA) and newly defined measurements (SNCEJ) had strong correlations with clinical upper lip diagnosis (P < 0.001). All statistically significant cephalometric variables had good intra- and interobserver reliability (correlation coefficients ≥0.972 and ≥ 0.968, respectively) except SNA, which had a low interobserver reliability (correlation coefficient 0.739). Fitted models for paranasal and upper lip analyses showed low micro-F scores, indicating low precision and recall. However, AUC values of 0.7019 and 0.6362 for the paranasal and upper lip analysis, respectively, suggest improved performance of the model when properly trained with a larger sample size. CONCLUSIONS: Newly defined measurements SNh and SNNP correlated with clinical paranasal diagnosis only in the absence of upper lip procumbency and protrusion. SNA and SNCEJ were strongly correlated with clinical upper lip diagnosis. However, fitted models based on this study sample yielded low micro-F scores, making the fitted models currently unsuitable for anything besides correlation with clinical findings. A larger sample size will be necessary to further clarify the potential roles of these measurements, especially given the reasonable AUC values. The findings of this study demonstrate the highly subjective and relative nature of midfacial diagnosis and the importance of clinical judgment despite the potential utility of some traditional and new measurements.

The "coracoid tunnel view": a simulation study for finding the optimal screw trajectory in coracoid base fracture fixation.

PURPOSE: Coracoid fractures represent approximately 3-13% of all scapular fractures. Open reduction and internal fixation can be indicated for a coracoid base fracture. This procedure is challenging due to the nature of visualization of the coracoid with fluoroscopy. The aim of this study was to develop a fluoroscopic imaging protocol, which helps surgeons in finding the optimal insertion point and screw orientation for fixations of coracoid base fractures, and to assess its feasibility in a simulation study. METHODS: A novel imaging protocol was defined for screw fixation of coracoid base fractures under fluoroscopic guidance. The method is based on finding the optimal view for screw insertion perpendicular to the viewing plane. In a fluoroscopy simulation environment, eight orthopaedic surgeons were invited to place a screw down the coracoid stalk through the coracoid base and into the neck of 14 cadaveric scapulae using anatomical landmarks. The surgeons placed screws before and after they received an e-learning of the optimal view. Results of the two sessions were compared and inter-rater reliability was calculated. RESULTS: Screw placement was correct in 33 out of 56 (58.9%) before, and increased to 50 out of 56 (89.3%) after the coracoid tunnel view was explained to the surgeons, which was a significant improvement (p < 0.001). CONCLUSIONS: Our newly developed fluoroscopic view based on simple landmarks is a useful addendum in the orthopaedic surgeon's tool box to fixate fractures of the coracoid base.