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The primary objective of this study was to examine the glenohumeral subluxation index (GHSI) in a large general population cohort and to define reference values. Glenohumeral subluxation is important in the development and prediction of pathological states of the shoulder joint and in total shoulder arthroplasty. Therefore, another objective was to examine the influence of age, sex, body mass index, and body height and weight on GHSI. GHSI according to Walch was measured on bilateral magnetic resonance imaging of 3004 participants of the Study of Health in Pomerania (SHIP, aged 21-90 years). SHIP drew a sample of the adult general population of Pomerania (Northeastern Germany). Reference values for GHSI were assessed by quantile regression models. Associations of sex, age, and anthropometric markers with the GHSI were calculated by linear regression models. A reference range between 42% and 55% for men with a mean of 49% ± 4% was defined, while the upper reference limit for women was 1% higher (mean, 50% ± 4%). Age was inversely associated with the GHSI in males (P < 0.001), while no significant association in females was observed (P =.625). Body weight and body mass index were positively associated (P <.001) without effect modification by sex. Heavy mechanical oscillations on the upper extremity showed no significant association with GHSI (P =.268). The reference values for GHSI were expanded to a range of 42%-57% on magnetic resonance imaging. Several associations between GHSI and anthropometric properties are present. According to these associations, adjusted formulas are provided to enable individual, patient-specific diagnostics and therapy. Nevertheless, the clinical picture cannot be neglected. [ABSTRACT FROM AUTHOR]

The suprascapular nerve block (SSNB) is a commonly used procedure for the management of pain in various shoulder pathologies. Both image-guided and landmark-based techniques have been utilized successfully for SSNB, though more consensus is needed regarding the optimal method of administration. This study aims to evaluate the theoretical effectiveness of a SSNB at 2 distinct anatomic landmarks and propose a simple, reliable way of administration for future clinical use. Fourteen upper extremity cadaveric specimens were randomly assigned to either receive an injection 1 cm medial to the posterior acromioclavicular (AC) joint vertex or 3 cm medial to the posterior AC joint vertex. Each shoulder was injected with a 10 ml methylene blue solution at the assigned location, and gross dissection was performed to evaluate the anatomic diffusion of the dye. The presence of dye was specifically assessed at the suprascapular notch, supraspinatus fossa, and spinoglenoid notch to determine the theoretic analgesic effectiveness of a SSNB at these 2 injection sites. Methylene blue diffused to the suprascapular notch in 57.1% of the 1-cm group and 100% of the 3-cm group, the supraspinatus fossa in 71.4% of the 1-cm group and 100% of the 3-cm group, and the spinoglenoid notch in 100% of the 1-cm group and 42.9% of the 3-cm group. Given its superior coverage at the more proximal sensory branches of the suprascapular nerve, a SSNB injection performed 3 cm medial to the posterior AC joint vertex provides more clinically adequate analgesia than an injection site 1 cm medial to the AC junction. Performing a SSNB injection at this location allows for an effective method of anesthetizing the suprascapular nerve. [ABSTRACT FROM AUTHOR]

Purpose: This work aimed to utilize virtual reality (VR) in dental radiographic anatomical interpretation in junior dental students and test if it can enhance student learning, engagement, and performance. Methods: VR software for panoramic anatomy was developed. Sixty‐nine first‐year dental students were divided into a control group (lecture‐based) and an experimental group (VR) to learn panoramic radiographic anatomy. Both groups were then tested on knowledge via a 20‐question quiz. Student feedback on VR experience was collected via an online survey. Results: There was a statistically significant difference between lecture‐based and VR students in the correct identification of anatomical landmarks. Lecture‐based students scored higher in identifying the ear lobe, hyoid bone, condylar neck, and external oblique ridge, whereas VR students scored higher in identifying zygoma (Chi‐squared test, p < 0.005). The VR group reported high evaluation on all perception items of the online feedback survey on their experience (Student t‐test, p < 0.005). Conclusions: Lecture‐based students generally showed better performance in panoramic radiographic anatomy. Several structures were not correctly identified in both groups of novice students. The positive feedback of VR experience encourages future implementation in education to augment conventional methods of radiographic anatomy in dentistry with considerations to repeated exposures throughout undergraduate dental education. [ABSTRACT FROM AUTHOR]

This audit describes the lymphatic flow from oral tumours seen on single-photon emission computed tomography (SPECT/CT) to help sentinel node (SN) identification. A total of 95 consecutive sentinel node biopsies (SNB) were taken between 2010 and 2019. Eligibility criteria for SNB were patients over 18 years of age with a T 1 -T 2 oral or oropharyngeal squamous cell carcinoma and an N 0 neck. SNs collect at high-frequency sites irrespective of the primary tumour (22.7% level Ib; 64.8% levels II/III; and 7.6% level IV), but with individual variation. Radiotracer activity did not influence the number of nodes identified, and metastatic deposits were found in the hottest nodes. SNs occur at the same high-frequency locations in the neck, so familiarity with anatomical detail may reduce false-negative results. [ABSTRACT FROM AUTHOR]

The temporo-mandibular joint (TMJ) has implications in vital functions and its disorder prevalence is between 5% and 12%. The mandible motions rely on two joints where mandibular condyles are generally asymmetric and highly individual. They rotate during jaw opening and closing and translate vertically and anteroposteriorly. Quantitative motion analysis tools are of interest to better understand normal and abnormal TMJ behavior. Previous studies have reported the asymmetrical behavior of the mandible compared to the skull as well as the synchronism of rotation and translation during its motions. But none of them has developed an experimental protocol using in vivo motion data fused with a tridimensional (3D) model. Therefore, we aim to provide the detailed kinematic parameters of the mandible compared to the skull, of the 2 condyles compared to their sockets and the instantaneous helicoidal axis (IHA) calculation through a clearly described new technology: in vivo data motion fused with virtual palpation on 3D models. We also compare the accuracy and the consistency of our results with the existing literature. Five healthy subjects fitted with a tailor-made dental and head clusters performed mouth opening/closing, diduction and chewing motions. 15 anatomical landmarks (ALs) were palpated on their skull and their mandible. The trajectory of the markers and ALs was recorded by opto-electronic cameras. 3D models created from magnetic resonance imaging (MRI) from the 5 subjects were processed through a segmentation procedure and imported into a musculo-skeletal data processing software. Virtual palpation was used to locate specific ALs and to build coordinate systems following the ISB recommendations. The ALs coordinates, the motion files and the morphological model were fused. Motion cycles were normalized from 1 to 100% of rotations and translations duration in coordinate systems, instantaneous helical axis (IHA) parameters were computed for the 3 motions. Median RMSE between manually and virtually palpated ALs was 8,0 mm. During opening motion, rotation around the Z-axis (median 24,9°), translations along the X-axis and the Y-axis (median 9,7 mm and 6,3 mm respectively) were happening all at once. The IHA was obliquely orientated. During diduction motion, rotations around the Y-axis and the X-axis (median 10,7° and 3.3° respectively), translation on the Z-axis is (median −9.4 mm) occurred simultaneously. The IHA orientation was oblique and changed accordingly to the diduction side. During chewing motion, median rotation around the Z-axis was −2.2° and median translation on the Y-axis −1.0 mm. The IHA pathway high asymmetry coincided with typical movements of working and balancing condyles. Complete 3D kinematics parameters of the TMJs, corresponding to the ISB recommendations, have been extracted with our methodology. Our values matched previous studies if available and the palpation RMSE was within the bounds of precedent experimental protocol. It is therefore efficient to study in vivo motion. Motion data have been registered in an open access data repository, allowing other researchers to exploit them and develop their own TMJ model. • Quantitative motion analysis is needed to understand normal and abnormal TMJ behavior. • Mandible motions compared to the skull are asymmetrical and three-dimensional. • We developed an experimental protocol fusing in vivo motion data with a 3D model. • We provide accurate TMJs kinematic parameters including the helicoidal axis. [ABSTRACT FROM AUTHOR]

Background This study aimed to have international experts converge on a harmonized definition of whole hippocampus boundaries and segmentation procedures, to define standard operating procedures for magnetic resonance (MR)-based manual hippocampal segmentation. Methods The panel received a questionnaire regarding whole hippocampus boundaries and segmentation procedures. Quantitative information was supplied to allow evidence-based answers. A recursive and anonymous Delphi procedure was used to achieve convergence. Significance of agreement among panelists was assessed by exact probability on Fisher's and binomial tests. Results Agreement was significant on the inclusion of alveus/fimbria ( P = .021), whole hippocampal tail ( P = .013), medial border of the body according to visible morphology ( P = .0006), and on this combined set of features ( P = .001). This definition captures 100% of hippocampal tissue, 100% of Alzheimer’s disease-related atrophy, and demonstrated good reliability on preliminary intrarater (0.98) and inter-rater (0.94) estimates. Discussion Consensus was achieved among international experts with respect to hippocampal segmentation using MR resulting in a harmonized segmentation protocol. [ABSTRACT FROM AUTHOR]

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Purpose To determine whether there is a measurable and reproducible relationship between the articular surface size of the middle phalanx base and the size of the middle phalanx head and proximal phalanx length of the same finger. Methods Size of the articular surface of the middle phalanx base, size of the middle phalanx head, and proximal phalanx length were measured in 84 lateral radiographs by 3 observers. Results The ratio of articular surface size of the middle phalanx base to the proximal phalanx length of the same finger was 0.17. The ratio of articular surface size of the middle phalanx base to the size of the middle phalanx head of the same finger was 1.34. The intraclass correlation (ICC) among 3 raters was 0.99 for proximal phalanx length and 0.88 for size of the middle phalanx head. Conclusions Knowledge of this relationship and ratios allow for accurate estimation of the percentage of articular surface involvement in a fracture of the middle phalanx base. The ICC was highest for measuring proximal phalanx length, making it the most reliable measurement for estimation of the articular surface size. Clinical relevance This quantitative estimate may be useful for clinical research and is applicable to patient care. [ABSTRACT FROM AUTHOR]

Abstract: Sagittal split ramus osteotomy (SSRO) of the mandible is one of the most common surgical techniques to correct mandibular deformities. Measurement of nerve position using conventional methods has been reported in the literature, but surgeons have found that further investigation of the anatomical relationship is needed. The aim of this study was to attempt to increase the accuracy of treatment by using 3-dimensional computed tomography scan measurements. From the normal population, 20 females and 20 males were enrolled during planning of denture implants in Taiwan. The mean age was 28±6, ranging from 20 to 39 years old. Using 3D tomography data, nerve position at osteotomy sites was measured and the geometric relationship examined between the antilingula and mandibular foramen. The results gave the mean distance from buccal plate to mandibular canal at the second molar, from mandibular canal to inferior border of the mandibular body, from the mandibular foramen to the highest tip of the lingula, and from the mandibular foramen to the anterior margin of the oblique ridge. When applied to SSRO operations, the anatomic data provided by this study may help surgeons gain more understanding of nerve position during surgery. [Copyright &y& Elsevier]

Abstract: Dissection deep within the orbit is a cause for concern to surgeons because of the perceived risks of injuring critical structures such as the contents of the superior orbital fissure and the optic nerve. Although “safe distances” (those distances within which it is considered safe to dissect within the orbit) have been described, these are of limited value if the orbit is severely disrupted or is congenitally shallow. In addition, traumatic defects in the orbital floor, in particular, often extend beyond these distances. Reliable landmarks based on the relations between anatomical structures within the orbit, rather than absolute distances, are described that permit safe dissection within the orbit. We present the concept of the deep orbit and describe its relevance to repair of injuries. [Copyright &y& Elsevier]

Abstract: For extramedullary tibial alignment in total knee arthroplasty, it is important to localize the center of the ankle mortise. Malpositioning of alignment jigs can produce varus or valgus implantation and can lead to inferior clinical and radiologic outcomes. In a cadaver study, we investigated the accuracy of palpable tendons as references for extramedullary tibial alignment in 86 anatomical specimens. To investigate tendon movement with pronation and supination in living patients, we additionally performed 10 magnetic resonance imaging scans. On average, the lateral border of the tibialis anterior tendon was measured 1 cm medial to the center of the talus. The extensor hallucis longus tendon was the most accurate anatomical landmark. Pronation had a small effect, but extensive supination can lead to tendon deviation greater than 1 cm. Our results suggest that the extensor hallucis longus can serve as a useful intraoperative reference to identify the center of the ankle mortise, particularly if marked preoperatively. [Copyright &y& Elsevier]

Literature regarding the optimal entry point at the plantar aspect of the heel for performing tibiotalocalcaneal arthrodesis with a locked retrograde intramedullary nail is plentiful, but fails to provide meaningful guidance beyond broad generalizations. Because of the complex nature of the procedure, which requires precise alignment of multiple joints, difficulties in guide-wire placement frequently arise. Furthermore, proper guide-wire placement is usually performed under image intensification, placing the patient, surgeon, and operating room personnel at risk of ionizing radiation. This study evaluates weight-bearing lateral radiographic and anatomical landmarks to determine the optimal guide-wire entry point at the plantar heel fat pad, as well as a prospective intraoperative evaluation of the efficacy of using these landmarks to properly seat the guide wire. Radiographic and anatomical landmark portions of the study revealed that the calcaneocuboid joint was located 18.5 ± 3.4 mm anterior to the tibia mid-diaphyseal line, and that the lower leg soft tissue outline approximated the calcaneocuboid joint to within 0.3 ± 1.2 mm. The intraoperative portion of the study revealed that by first aligning the guide wire with the lower leg soft tissue outline, which approximated the location of the calcaneocuboid joint, and then translating the wire approximately 2.0 cm posteriorly, the increase in the efficacy of properly seating the guide wire was statistically significant (P ≤ .0001). The author proposes that this technique improves the accuracy of guide-wire placement and decreases dependency on intraoperative image intensification. [Copyright &y& Elsevier]

This paper proposes a method of estimation of the anatomical landmarks that are needed in product design from point clouds of body shape measured by a three-dimensional scanner. The algorithm is described briefly. First, the standard model is defined as the average shape with anatomical landmarks calculated from multiple body data samples with given anatomical landmarks. Then, the matching transformation is applied to the standard model so that it fits the body shape data of the target model. The anatomical landmarks of the target body shape are estimated from the deformed standard model. Free-form deformation (FFD) is used as the matching transformation, in which the deformation control lattice coordinates are determined from an estimation formula derived by multiple regression analysis of the multiple body data sample. This method is applied to a foot model for shoe design. The effectiveness of the proposed method is verified by an experimental evaluation. © 2005 Wiley Periodicals, Inc. Syst Comp Jpn, 36(6): 26–38, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20270 [ABSTRACT FROM AUTHOR]

In this study relations between anatomical landmarks on the dorsal surface of the human torso corresponding to underlying skeletal structures are established. By examining the statistics of the positions of the landmarks in a training set of subjects a point distribution model is derived. Rotations of the pelvis are simulated in order to show that the main mode shapes of variation are consistent with rotations of the pelvis relative to the trunk. The parameters of these mode shapes can therefore be used as independent measures of clinical parameters such as pelvic inclination, pelvic tilt, etc. The point distribution model is further applied to improve reliability and robustness for an automatic and objective detection of the anatomical landmarks on the back surface (active shape model). The results show that it is possible to replace radiographs by surface measurements in order to measure position and orientation of the pelvis, which is particularly valuable in the case of functional examinations that normally involve a large number of radiographs (e.g. to measure the position of the pelvis in a scoliosis). [ABSTRACT FROM AUTHOR]