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The temporomandibular joint (TMJ) is a distinguishing feature of mammals, and in most mammals includes an articular disc that buffers the loads placed on it by mastication. The disc is well developed in mammals with significant lateral masticatory jaw movements but is absent in toothless mammals, including extant monotremes, although histological studies of developing monotremes have shown rudimentary discs that fail to mature. Platypus (Ornithorhynchus anatinus) grind their food between keratinous pads in the maxillae and lower jaws and are the only edentulate mammals that masticate their food. In this study, we characterize the anatomy of the TMJ of the adult platypus to see if we can reconcile the anatomy, including the absence of the articular disc, with the mandibular movements observed in video recordings. We studied the gross anatomy of the maxillofacial region and the microstructure using microcomputed tomography (micro‐CT) and histological examination. Platypuses had well‐developed masticatory muscles but lacked an articular disc between the mandibular condyle and glenoid fossa. The surface of the glenoid fossa was slightly concave than that of the condylar head was correspondingly slightly convex. The pre‐ and postglenoid processes were not well developed. Micro‐CT showed dense trabecular bone in the anterior part of the condyle, where the lateral pterygoid muscle attached. Histological analysis showed that the surfaces of the condyle and glenoid fossa consisted of dense, avascular and thickened fibrous connective tissue. In addition, well‐developed synovial folds were present. These anatomical characteristics are consistent with both anterior and lateral movements of the mandible, while the thick layer of connective tissue substitutes for a disc by absorbing the mechanical stresses associated with mastication. The failure of the disc primordium to develop cannot be attributed to a lack of muscle development, but the distribution of stresses in the toothless platypus jaw is likely to be different from those in a masticating eutherian. [ABSTRACT FROM AUTHOR]

Objective: Our study aims to quantitatively determine the concavity of the glenoid articular surface in patients with hypermobile shoulders compared to those without. Method: We examined medical records of shoulder CTs from 2017 to 2022, selecting 50 patients with clinical signs of joint hypermobility for our case group and 54 for our control group. Two blinded readers independently assessed the glenoid morphology, calculating the glenoid concavity angle (GCA) and evaluating the articular surface shape as concave, flat, or convex. They also recorded the presence and severity of glenoid dysplasia. We compared these assessments between groups. Results: The mean GCA was significantly lower in the hypermobile group (2.3 ± 3.7° and 2.3 ± 3.8°) versus controls (6.6 ± 3.3° and 5.3 ± 3.8°) (P < 0.05). Interobserver reproducibility was high (ICC=0.76). A stark difference in glenoid morphology was noted between groups (P < 0.001), with a majority of hypermobile patients having a flat or convex glenoid. GCAs decreased with increasing shoulder laxity and dysplasia. GCA showed 77–81 % sensitivity and 55–82 % specificity for detecting shoulder hyperlaxity with a 4° cutoff. Conclusion: There is a significant association between GCA and shoulder hyperlaxity, demonstrating diagnostic efficacy and substantial interobserver agreement. Clinical Relevance: GCA values lower than 4° warrant further clinical investigation for shoulder hyperlaxity and associated conditions, which is crucial for patient treatment planning.

Objective: The objective of this study was to obtain the morphological and morphometric variations of the glenoid cavity of the scapula in the population of Bihar and compare it to that of the study done in different races by the previous author. Method: A total of 120 dry adult human scapulae of unknown age and sex in which 60 belong to the right side and 60 belonging to the left side were obtained from the Department of Anatomy and forensic medicine of Indira Gandhi Institute of Medical Sciences, Patna and also from other medical colleges of Bihar. Results: The most common shape of the glenoid cavity recorded in this study was pearshaped followed by inverted comma-shaped. The least common shape was oval. The mean scapular length was observed as 137.11±8.72 mm, the mean breadth of scapula was 98.73±10.92 mm, the mean supero-inferior glenoid diameter was 36.34±3.91 mm, the mean anteroposterior glenoid diameter was 24.95±4.58 mm and mean glenoid cavity index was 68.82±10.33. Conclusion: Morphological and morphometric analysis of the glenoid cavity of the scapula is very important during designing and fitting of glenoid components in total shoulder arthroplasty and its associated shoulder pathology. [ABSTRACT FROM AUTHOR]

The aim of this systematic review was to collect evidence on the following 10 technical aspects of glenoid baseplate fixation in reverse total shoulder arthroplasty (rTSA): screw insertion angles; screw orientation; screw quantity; screw length; screw type; baseplate tilt; baseplate position; baseplate version and rotation; baseplate design; and anatomical safe zones. Five literature libraries were searched for eligible clinical, cadaver, biomechanical, virtual planning, and finite element analysis studies. Studies including patients >16 years old in which at least one of the ten abovementioned technical aspects was assessed were suitable for analysis. We excluded studies of patients with: glenoid bone loss; bony increased offset-reversed shoulder arthroplasty; rTSA with bone grafts; and augmented baseplates. Quality assessment was performed for each included study. Sixty-two studies were included, of which 41 were experimental studies (13 cadaver, 10 virtual planning, 11 biomechanical, and 7 finite element studies) and 21 were clinical studies (12 retrospective cohorts and 9 case-control studies). Overall, the quality of included studies was moderate or high. The majority of studies agreed upon the use of a divergent screw fixation pattern, fixation with four screws (to reduce micromotions), and inferior positioning in neutral or anteversion. A general consensus was not reached on the other technical aspects. Most surgical aspects of baseplate fixation can be decided without affecting fixation strength. There is not a single strategy that provides the best outcome. Therefore, guidelines should cover multiple surgical options that can achieve adequate baseplate fixation. [ABSTRACT FROM AUTHOR]

This study aimed to characterize three-dimensional quantitative morphological changes of glenoid fossa in patients with skeletal Class III malocclusion treated with bimaxillary orthognathic surgery. Ninety-five eligible patients (50 male, 45 female; mean age 22.09 years) were enrolled retrospectively. Cone beam computed tomography obtained at 1 week preoperatively (T0), immediately after surgery (T1), and at ≥ 12 months postoperatively (T2) were registered based on cranial base using voxel-based registration in 3D Slicer. Glenoid fossa surface was divided spatially into four regions, and bone modelling in these regions was visualized with color maps. Our data revealed that the mean surface variations of glenoid fossa were small, with modest bone formation as a whole. No significant associations between anteroposterior or vertical mandibular displacement and overall glenoid fossa remodeling were found (P > 0.05). Moreover, bone deposition was frequently observed in the anterior-lateral region of glenoid fossa in patients with a larger mandibular movement during T0–T1 (P < 0.001). Paired bone formation in the anterior-lateral region of glenoid fossa and bone resorption in the anterior-lateral region of condylar head was frequently observed. Collectively, our results revealed that glenoid fossa underwent complex but modest bone remodeling after bimaxillary surgery in skeletal Class III patients. [ABSTRACT FROM AUTHOR]

The aim of this systematic review was to collect evidence on the following 10 technical aspects of glenoid baseplate fixation in reverse total shoulder arthroplasty (rTSA): screw insertion angles; screw orientation; screw quantity; screw length; screw type; baseplate tilt; baseplate position; baseplate version and rotation; baseplate design; and anatomical safe zones. Five literature libraries were searched for eligible clinical, cadaver, biomechanical, virtual planning, and finite element analysis studies. Studies including patients >16 years old in which at least one of the ten abovementioned technical aspects was assessed were suitable for analysis. We excluded studies of patients with: glenoid bone loss; bony increased offset-reversed shoulder arthroplasty; rTSA with bone grafts; and augmented baseplates. Quality assessment was performed for each included study. Sixty-two studies were included, of which 41 were experimental studies (13 cadaver, 10 virtual planning, 11 biomechanical, and 7 finite element studies) and 21 were clinical studies (12 retrospective cohorts and 9 case-control studies). Overall, the quality of included studies was moderate or high. The majority of studies agreed upon the use of a divergent screw fixation pattern, fixation with four screws (to reduce micromotions), and inferior positioning in neutral or anteversion. A general consensus was not reached on the other technical aspects. Most surgical aspects of baseplate fixation can be decided without affecting fixation strength. There is not a single strategy that provides the best outcome. Therefore, guidelines should cover multiple surgical options that can achieve adequate baseplate fixation.

Introduction: The multitude of definitions for the centric relation (CR) has sparked extensive scientific debates, marking significant milestones in the evolution of concepts in these fields. The discourse surrounding CR has remained contentious for over a century, and there is still a persistent divergence of perspectives. Aim: This narrative review aims to unravel the evolutionary trajectory of CR definitions, seeking to untangle the existing confusion prevalent within specialized literature. Moreover, it endeavors to provide guiding principles within this contentious domain, offering valuable insights to practitioners, students, educators, and researchers. Discussion: Dentistry has not arrived at a consensus definition and concept of CR. Even in the era of evidence-based dentistry, CR still leaves room for controversy. Conclusion: The evolution of the CR concept and its definition, progressing from the exact specification of the maxillomandibular relationship, temporomandibular joint elements, and hinge axis and to its partial “abandonment” due to the individuality and particularities of the patients, should be contextualized within the functional and adaptable nature of the stomatognathic system.

A 13-year-old male was diagnosed with a glenoid fracture following direct shoulder trauma, for which surgical treatment was considered. After referral to a center for pediatric orthopedic care, physical examination, contralateral shoulder X-ray, and detailed computed tomography examination ruled out the presence of fracture; these findings were later confirmed by magnetic resonance imaging. Normal ossification patterns in the adolescent shoulder may simulate a fracture in traumatic settings. To accurately diagnose and manage pediatric shoulder pathology, orthopedic surgeons must be aware of the normal anatomy of the growing shoulder, its secondary ossification centers, and growth plates. Level of evidence V.

The position of the mandible after an orthognathic surgical procedure is believed to be dependent on adaptive condylar and glenoid fossa changes, in addition to condylar positional changes within the fossa. The purpose of this study was to evaluate the association between condylar and glenoid fossa changes and the positional changes in the joint space two years after bimaxillary surgery. The condyles and glenoid fossae were reconstructed from a pair of superimposed pre- and postoperative (two years) cone-beam computerized tomography scans. The surface models were spatially divided into four regions. Three-dimensional morphological and positional changes were measured as volumetric differences and surface distances between the pre- and postoperative condylar and glenoid fossa regions. Statistical associations of condylar, glenoid fossa and joint space changes were calculated by Pearson's correlation coefficient. Twenty subjects (sixteen female; four male; mean age 27.6 years) with class II malocclusion and maxillomandibular retrognathia, who underwent bimaxillary surgery, were assessed. A strong and statistically significant correlation between condylar and glenoid fossa changes was observed two years after surgery (r = 0.52, p

This article provides a comprehensive overview of the concept of centric relation (CR) in dentistry. It explores the different definitions and controversies surrounding CR, emphasizing the lack of consensus in the field. The article emphasizes the importance of understanding CR in prosthetic rehabilitation and its impact on occlusion and temporomandibular joint (TMJ) health. It concludes by highlighting the need for a more specific and standardized terminology for describing CR. Overall, this text is a valuable resource for researchers and healthcare professionals seeking to understand the complexities of CR in dentistry. [Extracted from the article]

Objective: The glenopolar angle is a helpful criterion for recommending operative treatment. This study aims to determine the morphometric features of the scapula and provide essential information that supplies scapular biomechanics to produce a formula. Methods: The study was carried out on 34 dry scapulae in the laboratory of the Anatomy Department of the Faculty of Medicine, Bursa Uludag University. We used calipers for the linear measurements and the ImageJ program for the area and angle parameters. A total of 23 parameters were evaluated in the study. Statistical analyzes were performed using SPSS 22.0 software. Results: According to the results of the correlation analysis, the highest correlation value of (R=0.957) was found to be the distance between the superior angle (angulus superior)-top of the glenoid plane and the inferior angle (angulus inferior)-the top of the glenoid plane. To estimate the glenopolar angle, we applied linear regression analysis and developed the following formula: Glenopolar angle =115.589 - (6.401 x the distance between the coracoid process and the top of the glenoid cavity) - (0.368 x angle between the glenoid plane and the lateral edge of the scapula extending towards the endpoint of the glenoid plane) (Adjusted R² =0.667). Conclusions: Glenopolar angle can provide information about the fracture risk of the glenoid cavity and allows orthopedic surgeons to make quick decisions about the risk in the region. We believe that the study will provide a different perspective on designing different products in industrial designs for shoulder joints, especially in implantations. [ABSTRACT FROM AUTHOR]

A 13-year-old male was diagnosed with a glenoid fracture following direct shoulder trauma, for which surgical treatment was considered. After referral to a center for pediatric orthopedic care, physical examination, contralateral shoulder X-ray, and detailed computed tomography examination ruled out the presence of fracture; these findings were later confirmed by magnetic resonance imaging. Normal ossification patterns in the adolescent shoulder may simulate a fracture in traumatic settings. To accurately diagnose and manage pediatric shoulder pathology, orthopedic surgeons must be aware of the normal anatomy of the growing shoulder, its secondary ossification centers, and growth plates. [ABSTRACT FROM AUTHOR]

Introduction: Gender is the most vital segment of the biological characteristics which can be evaluated from the skeleton because of the marked sexual dimorphism of bone segments. The aim of this study is to evaluate the effect of gender on the scapula measure for healthy sedentary subjects. The parameters used in the present study were different from the previous research. Hence, the current work was designed to measure gender differences of the scapula in the Iranian population. The aim of this study is to evaluate the effect of gender on the scapula measure for healthy sedentary subjects. The design of this research has been done with the coordination and activity of all authors to examine the effect of gender in scapula characters. Material and Methods: This study was performed on scapula computed tomography in 68 patients. These characters in this bone: acromion glenoid distance, length of the acromion, width of acromion, acromion coracoid distance, length of scapula, width of scapula, length of coracoid (LC), length of glenoid (LG), and width of glenoid. With the help of the SPSS software, the logistical regression equation was derived from the stepwise method. By multiplying the value of each dimension with its corresponding coefficient (β coefficient) and adding the products together along with the appropriate constant, the sex of a specimen can be determined. For the regression equation incorporating all for scapular dimensions, the logistic regression score (Y) is calculated as follows: Y = (-0.003 × Width of scapula (WS)) + (0.006 × LC) + (-0.14 × height of glenoid [HG]) + 2.098. Results: This study shows the scapular bone characteristic comparison between the two sexes, which statistically significant difference in the width of the bone scapula (P = 0.02) and the coracoid length (P = 0.04) and LG (P = 0.01). In males, significant positive correlation was found between Height of scapula (HS), and height of glenoid (HG) (0.884) and in females, significant positive correlation was maximum the relationship between the HS and LC (0.904**). Discussion and Conclusion: Due to the small number of our samples, it would be better to study more widely so that other differences such as the length of the scapula and the glenoid width can be achieved, and more confidently, that these two attributes do not play a role in determining the sex. [ABSTRACT FROM AUTHOR]

Objectives: A morphocline of the glenoid cavity has been used to infer differences in locomotor behaviors; however, the glenoid cavity is surrounded by the glenoid labrum, a fibrocartilaginous structure that could influence the functionality of the glenoid. The objectives of this study are to explore the effects of the glenoid labrum on the area, depth, and morphology of the glenoid cavity in primates. Materials and Methods: Photogrammetry was used to build 3D models of the glenoid, with and without the labrum, and three‐ (3D) and two‐dimensional (2D) geometric morphometrics (GM) was applied. 2D areas were collected from zenithal images for glenoids with and without labrum to evaluate the availability of articular surface area. Results: In the 2D GM the morphocline is present in the dry‐bone sample but not with the presence of the glenoid labrum. In the 3D GM there are differences between species mainly concerning the depth of the glenoid cavity. 2D areas reveal that the amount of articular area of the glenoid cavity increases with the presence of the labrum, particularly in humans. Discussion: The glenoid labrum changes the shape, increases the depth and the surface area of the glenoid cavity, particularly in humans. Therefore, the glenoid labrum might hold a functional role, increasing the stability of the glenohumeral joint of primates in general, and especially in humans. [ABSTRACT FROM AUTHOR]

Objectives: To determine the diagnostic accuracy of non-arthrographic MR imaging, conventional MR arthrography, and 3D T1-weighted volumetric interpolated breath-hold examination (VIBE) MR arthrography sequences as compared with a CT arthrography in the diagnosis of glenoid bare spot. Methods: A retrospective study of 216 patients who underwent non-arthrographic MR imaging, conventional MR arthrography, VIBE MRI arthrography, and CT arthrogram between January 2011 and March 2022 was conducted. The diagnostic accuracy of non-arthrographic MR imaging, direct MR arthrography, and VIBE MRI arthrography in the detection of glenoid bare spot was compared with that of CT arthrography. All studies were reviewed by 2 MSK radiologists. Interobserver agreement for MR imaging and MR arthrographic findings was calculated. Results: Sixteen of 216 patients were excluded. Twenty-three of 200 shoulders had glenoid bare spot on CT arthrographic images. The glenoid bare spot was detected in 11 (47.8%) and 7 (30.4%) patients on conventional non-arthrographic MR images and in 18 (78.3%) and 16 (69.6%) patients on conventional MR arthrograms by observers 1 and 2, respectively. Both observers separately described the bare spot in 22 of 23 patients (95.7%) on 3D volumetric MR arthrograms. Interobserver variabilities were fair agreement for conventional non-arthrographic MR imaging (κ = 0.35, p < 0.05), moderate agreement for conventional MR arthrogram (κ = 0.50, p < 0.05), and near-perfect agreement for 3D volumetric MR arthrogram reading (κ = 0.87, p < 0.05). Conclusions: A 3D high-resolution T1-weighted VIBE MR arthrography sequence may yield diagnostic performance that is comparable with that of CT arthrography in the diagnosis of glenoid bare spot. Key Points: •Glenoid bare spot should not be misdiagnosed as a transchondral defect of the glenoid surface by radiologists. •A 3D high-resolution T1-weighted VIBE MR arthrography sequence may be used as a high-sensitivity imaging technique in the diagnosis of glenoid bare spot. [ABSTRACT FROM AUTHOR]

Objective:This study aimed to determine the relationship between the morphologic characteristics of condyle and glenoid fossa in different sagittal skeletal patterns using cone-beam computed tomography.Methods:In this cross-sectional study, the lateral cephalometric and cone-beam computed tomography images of 90 patients were evaluated. The patients were categorized into three equal groups of sagittal skeletal patterns, according to the ANB angle. The greatest anteroposterior and mediolateral diameters of the mandibular condyles, as well as the angle between the long axis of the mandibular condyles and the midsagittal plane, were measured on the axial view of cone-beam computed tomography images. The anterior joint space, superior joint space, posterior joint space, articular eminence inclination, depth of the glenoid fossa, and width of the glenoid fossa were also measured on the central sagittal slices. One-way analysis of variance (ANOVA), Tukey’s post hoc test and chi-square test were performed.Results:Patients with the skeletal Class III had a significantly higher articular eminence inclination, while Class II patients had a lower articular eminence inclination (P = .001). In Class III patients, the depth of the glenoid fossa was greater, and the width of the glenoid fossa was smaller than in the other groups (P < .01). The anterior and posterior joint space did not show any significant differences between the 3 groups.Conclusion:There were significant differences in some morphological characteristics of the condyle and glenoid fossa in patients with different sagittal skeletal patterns; therefore, this relationship should be considered in the treatment of these patients.

Relevance. Scapula is one of the bones that takes part in the formation of shoulder joint and has variable morphology. It is weak joint because glenoid cavity is variable in vertical diameter and transverse diameter. Hence glenoid cavity is shallow and gives rise to frequent dislocation of shoulder joint. Aim of the present study was to know various dimensions of glenoid cavity like vertical diameter and horizontal diameter and their variations in percentages. Materials and Methods. Fifty unknown dry human scapulae from the department of anatomy (Mahatma Gandhi Medical College, Sitapura, Jaipur, Rajasthan, India) constituted the materials for the present study. Each scapula was studied for glenoid cavity. The vertical diameter and horizontal diameters were studied from each above scapula. Twenty five scapulae were from right side and twenty five were from left side. The different shapes of glenoid cavity were observed. The shapes were pear shaped, inverted comma shaped and oval shaped. Results and Discussion. In the present study pear shaped glenoid cavity was found in 56 %, Inverted comma shape was found in 26 % and oval shape was observed in 18 %. The most common shape was pear shape (56 %) and least common shape was oval shape (18 %). The mean glenoid height was 35.52 mm. The maximum glenoid height was 41.22 mm and minimum glenoid height was 30.19 mm. The mean glenoid width was 20.77 mm. The maximum glenoid width was 24.31 mm and minimum glenoid width was 17.93 mm. Conclusion. Study showed that glenoid cavity has varied morphology. This varied morphology will be of great useful in various clinical and surgical procedures like hip replacement and in posterior glenoid osteotomy.

Aim: The aim of this study was to determine the notch and shape variations of the glenoid cavity (GC), to emphasize its clinical importance, and compare it with the previous studies. Material and Methods: This study was performed with 157 (78 right sides, 79 left sides) adult Anatolian dry scapulae. The GCs were typed as oval, pear, and inverted comma shaped and noted the number of GC notch. Results: The most common GC shape was found as the pear shaped with 63 (80.8%) at the right side, 49 (62%) at the left side, and 112 (71.4%) in total. The second most common GC shape was found as oval shaped with 13 (16.6%) at the right side, 28 (35.5%) at the left side, and 41 (26.1%) in total. The glenoid notch was found at the right side, left side, and totally; 28 (35.9%), 19 (24.1%), and 47 (29.9%), respectively. All of the inverted comma shaped GCs had distinct glenoid notch, while the oval shaped GCs not. The pear shaped GCs had indistinct glenoid notch or no glenoid notch. The glenoid notch was found at the right side, left side, and totally on the pear shaped GC; 26 (41.3%), 17 (34.7%), and 43 (38.4%), respectively. Conclusion: Pear shaped GC was found as the most (71.4%) common shape in this study. Forty-seven (29.9%) of the scapulae had a glenoid notch. The notch and shape variations of the GC are important and this study will contribute to anatomists, orthopedists, and radiologists from this perspective.

Background: The purpose of this study was to examine the various shapes and record the morphometric data of the glenoid cavity in a Chinese population. Materials and methods: A total of 501 scapulae, 247 left and 254 right, were analysed. We classified the shape of the glenoid cavity as type I (pear-shaped), type II (oval-shaped), type III (teardrop-shaped), type IV (calabash-shaped) or type V (inverted comma-shaped). Four defined parameters, the superior-inferior glenoid diameter (AB), upper anterior-posterior glenoid diameter (CD), lower anterior-posterior glenoid diameter (EF) and glenoid index (GI), were measured, and five shapes were classified via three-dimensional reconstruction. Results: The mean AB, CD, EF and GI values of the glenoid were 3.51 ± 0.41 cm, 1.95 ± 0.28 cm, 2.60 ± 0.34 cm, and 1.35 ± 0.12 cm, respectively. The AB value of type II glenoid cavities was significantly smaller than that of type I and III glenoid cavities (p < 0.05), but the GI value of type II glenoid cavities was larger than that of type III cavities (p < 0.05). The CD value showed a difference between type I and type III glenoid cavities (p < 0.05). For the EF parameter, the values of type III glenoid cavities were significantly larger than those of type I and II glenoid cavities (p < 0.05). Conclusions: Measuring and observing the variety of shapes and sizes of the glenoid cavity in Chinese people is conducive to for better understand its morphological features. This information can also guide surgeons in the design and selection of suitable prostheses for total shoulder arthroplasty in the Chinese population in order to reduce postoperative complications. [ABSTRACT FROM AUTHOR]

Background and Aim: Determining the sex of an individual is possible when we apply appropriate statistical methods using scapular measurements. Determination of sex using scapular measurements is very useful in medicolegal cases, natural disasters and in certain circumstances in which traditionally used bones of skeleton are either absent or fragmented. This study aims to assess sexual dimorphism for identification purposes. Material and Methods: This study was conducted using 40 adult skeletons (25 males and 15 females) with closed epiphysis having intact and well-preserved scapulae. Scapulae were measured in millimetre for MSH, MSB, GCH and GCB with the help of the sliding calliper. For all tests, confidence level and level of significance were set at 95% and 5% respectively. Results: There was a highly significant difference (P < 0.001) between male and female for the mean value of all measurements. So it indicates the existence of strong sexual dimorphism in scapula. Conclusion: Geometric morphometrics techniques feature promising results in the evaluation of skeletal sexual dimorphism, including in the size and shape of the scapula. The results of this study are very useful for sex determination in forensic anthropological and medicolegal cases where skull and pelvic bones are unavailable or damaged. The present study has confirmed that gender can be determined with high accuracy by use of scapular measurements. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to determine the relationship between the morphologic characteristics of condyle and glenoid fossa in different sagittal skeletal patterns using cone-beam computed tomography. Methods: In this cross-sectional study, the lateral cephalometric and cone-beam computed tomography images of 90 patients were evaluated. The patients were categorized into three equal groups of sagittal skeletal patterns, according to the ANB angle. The greatest anteroposterior and mediolateral diameters of the mandibular condyles, as well as the angle between the long axis of the mandibular condyles and the midsagittal plane, were measured on the axial view of cone-beam computed tomography images. The anterior joint space, superior joint space, posterior joint space, articular eminence inclination, depth of the glenoid fossa, and width of the glenoid fossa were also measured on the central sagittal slices. One-way analysis of variance (ANOVA), Tukey's post hoc test and chi-square test were performed. Results: Patients with the skeletal Class III had a significantly higher articular eminence inclination, while Class II patients had a lower articular eminence inclination (P = .001). In Class III patients, the depth of the glenoid fossa was greater, and the width of the glenoid fossa was smaller than in the other groups (P < .01). The anterior and posterior joint space did not show any significant differences between the 3 groups. Conclusion: There were significant differences in some morphological characteristics of the condyle and glenoid fossa in patients with different sagittal skeletal patterns; therefore, this relationship should be considered in the treatment of these patients. [ABSTRACT FROM AUTHOR]

Abstract Much is discussed about the limits of the treatment of anterior shoulder instability by arthroscopy. The advance in understanding the biomechanical repercussions of bipolar lesions on shoulder stability, as well as in the identification of factors related to the higher risk of recurrence have helped us to define, more accurately, the limits of arthroscopic repair. We emphasize the importance of differentiation between glenoid bone loss due to erosion (GBLE) and glenoid edge fractures, because the prognosis of treatment differs between these forms of glenoid bone failure. In this context, we understand that there are three types of bone failure: a) bone Bankart (fracture); b) combined; and c) glenoid bone loss due to anterior erosion (GBLE), and we will address the suggested treatment options in each situation. Until recently, the choice of surgical method was basically made by the degree of bone involvement. With the evolution of knowledge, the biomechanics of bipolar lesions and the concept of glenoid track, the cutoff point of critical injury, has been altered with a downward trend. In addition to bone failures or losses, other variables were added and made the decision more complex, but a little more objective. The present update article aims to make a brief review of the anatomy with the main lesions found in instability; to address important details in arthroscopic surgical technique, especially in complex cases, and to bring current evidence on the issues of greatest divergence, seeking to guide the surgeon in decision making.

Introduction: Morphometric study of spinoglenoid notch, coracoacromial arch, and another measurement of the scapulae are required to understand the reason for spasms of common muscle due to supraspinatus tendinitis, nerve compression over the spinoglenoid notch. Therefore, the aim of this study was to discuss the subcoracoacromial arch, deviation of the spinous process, and measurement of the spinoglenoid notch. Materials and Methods: This study was conducted at the Department of Anatomy, Sri Venkateshwaraa Medical College Hospital & Research Centre, Chennai, Tamil Nadu, India on 70 scapulae that include 58 non-articulated scapulae and 12 articulated scapulae. All the measurements were performed with a vernier caliper and the alignment of the spinous process of the scapula was measured with a goniometer. All the measurements are compared on both sides. Results: All the measurements were performed and presented as mean with standard deviation. We found the variation of diameter between the left and right sides. Spinoglenoid notch diameters were noted as anterior to posterior right 2.97 ± 0.37 cm, left 3.06 ± 0.56 cm and medial to lateral right 1.36 ± 0.14 cm, left 1.4 ± 0.08 cm. Subcoracoacromial arch was observed as right 1.85 ± 0.23 cm and left 1.92 ± 0.4 cm. The direction of the spinous process of the scapula was noted as right 21.50º ± 8.50 and left 18.8º ± 7.89. Conclusion: The present morphometric study findings may give a different approach to supraspinatous tendinits, shoulder instability, and dislocation cases due to morphometric changes present in the spinous process, acromion process, glenoid cavity, and spinoglenoid notch of the scapula. These morphometric studies on scapula can help radiologists, orthopedicians, and physiotherapists to plan patient management.

Background: The morphology and morphometry of the scapula and its glenoid fossa and acromion process play a significant role in the mechanics of shoulder joint. A variable morphology is found in glenoid fossa that has clinical implications. Aims and Objectives: The aim of the study was to evaluate the morphology and morphometry of dry scapula with emphasis on glenoid fossa and acromion process. Materials and Methods: A cross-sectional study was conducted at the department of anatomy, for a period of 6 months from January 2021 to June 2021. A total of 100 unpaired dry scapula were included in the study. The morphology and dimensions were measured. The dimensions were summarized as mean and standard deviation. Statistical analysis was done Chi-square test and student’s t-test based on the variable types. Results: Out of 100 scapulae studied, 48 were right sided and 52 were left sided. The mean of maximum length of the right scapula was 149.58±10.33 mm and the left side was 148.63±10.33 mm. Among the glenoid cavities, 54 were inverted comma shaped, 30 were pear shaped, and 16 were oval shaped. In one right-sided scapula Bony Spur Extends from Base of coracoid process to supra Scapular Notch. Conclusion: Size and shape of the glenoid cavity are directly related to the dislocation of shoulder joint and may affect the results of total shoulder arthroplasty and rotator cuff surgeries. The present study analyzed the morphological types and diameters of the glenoid cavity in adult scapulae to improve the efficacy and minimize the failure rates in shoulder arthroplasty particularly those involving the glenoid component of the shoulder joint.

Abstract Objective To evaluate and compare the glenoid track method in 3D-reconstructed computed tomography (3D-CT) scans with magnetic resonance imaging (MRI) and/or arthro-MRI. Methods Forty-four shoulders with clinical and radiographic diagnosis of traumatic anterior instability were assessed using 3D-CT, MRI, and/or arthro-MRI scans. Glenoid track (GT), Hill-Sachs interval (HSI), and glenoid bone loss (GBL) were determined by a radiologist using 3D-CT images, and classified as on-track/off-track. Three surgeons, blinded to the radiologist’s evaluation, performed the same determinations using MRI/arthro-MRI. Descriptive analysis, variance analysis, results disagreement analysis, and receiver operating characteristic (ROC) curves were performed. Results Results from the 4 examiners were fully consistent in 61.4% of the cases. Magnetic resonance imaging/arthro-MRI diagnosed off-track injuries with 35 to 65% sensitivity and on-track injuries, with 91.67 to 95.83% specificity. Accuracy ranged from 68.1 to 79.5%. The greatest data divergence occurred for off-track injuries diagnosed by MRI/arthro-MRI. The greatest data variability referred to HSI calculation. Higher HSI and GBL values were associated with greater disagreement among examiners. Hill-Sachs interval values were lower at MRI/arthro-MRI when compared to 3D-CT. Agreement between CT and MRI/arthro-MRI for the GT method was only moderate (kappa value, 0.325-0.579). Conclusion Magnetic resonance imaging/arthro-MRI showed low accuracy and moderate agreement for the GT method; as such, it should be used with caution by surgeons.

Objective: Our study aims to quantitatively determine the concavity of the glenoid articular surface in patients with hypermobile shoulders compared to those without., Method: We examined medical records of shoulder CTs from 2017 to 2022, selecting 50 patients with clinical signs of joint hypermobility for our case group and 54 for our control group. Two blinded readers independently assessed the glenoid morphology, calculating the glenoid concavity angle (GCA) and evaluating the articular surface shape as concave, flat, or convex. They also recorded the presence and severity of glenoid dysplasia. We compared these assessments between groups., Results: The mean GCA was significantly lower in the hypermobile group (2.3 ± 3.7° and 2.3 ± 3.8°) versus controls (6.6 ± 3.3° and 5.3 ± 3.8°) ( P < 0.05). Interobserver reproducibility was high (ICC=0.76). A stark difference in glenoid morphology was noted between groups ( P < 0.001), with a majority of hypermobile patients having a flat or convex glenoid. GCAs decreased with increasing shoulder laxity and dysplasia. GCA showed 77-81 % sensitivity and 55-82 % specificity for detecting shoulder hyperlaxity with a 4° cutoff., Conclusion: There is a significant association between GCA and shoulder hyperlaxity, demonstrating diagnostic efficacy and substantial interobserver agreement., Clinical Relevance: GCA values lower than 4° warrant further clinical investigation for shoulder hyperlaxity and associated conditions, which is crucial for patient treatment planning., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

This document is a letter to the editor of the Medeniyet Medical Journal, titled "Corrections Regarding 'Investigation of Morphological and Biomechanical Properties of the Scapula for Shoulder Joint'." The authors of the letter address two issues in the original article. First, they explain that a negative result emerged due to a revision in the units of measurement used. Second, they mention that certain parameters were evaluated in the study despite not being available in the literature. The authors also provide additional clarifications regarding the figures and measurements used in the study. [Extracted from the article]

This document is a letter to the editor of the Medeniyet Medical Journal, titled "Clarifications Regarding 'Investigation of Morphological and Biomechanical Properties of the Scapula for Shoulder Joint'." The authors of the letter express their interest in the article and commend the authors for their efforts. However, they raise several points of clarification and concern, including negative values in calculations, missing references, and incomplete information about the sample size and scapulae used. They also request clarification on the use of the term "biomechanics" in relation to a study conducted on dry bone. The authors conclude by expressing their appreciation for the editor's consideration and requesting a response from the original authors. [Extracted from the article]

The aim of this study is to contribute to sex determination studies from the scapula in the Turkish population and compare with previous studies. This study was performed with 200 scapulae (100 males and 100 females). The age range of the patients was between 18-93 years old. Computed tomography scans were used and length of glenoid cavity (LGC), breadth of glenoid cavity (BGC), depth of glenoid cavity (DGC), perimeter (PM) and volume (VL) were measured. Randomly selected 20 scapulae were measured three times for examine the intra-rater reliability from those measurements. Gender logistic regression analysis was conducted to find the significant variables at sex determination from the scapula. The most effective parameter in determining sex from scapula was found to be VL (88.5%). The effects of LGC, PM, BGC and DGC at sex determination from scapula were found to be 83%, 82.5%, 79.5%, 66%, respectively. The combination of VL and PM (89.5%) was found to be the most effective combination at sex determination from the scapula. The intraclass correlation values of all measurements were found to be at high reliability. According to the literature, PM and DGC along with the VL in Turkish population, were not used previously for sex determination from the scapula. A combination of the VL and PM was found to be the most effective parameters at sex determination from scapula in the Turkish population. There are few studies on the sex determination from scapula in the Turkish population. This study will guide anthropologists, forensic scientists and anatomists at sex determination studies from scapula and surgeons by morphometrically in clinical situations related to the scapula. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to determine the notch and shape variations of the glenoid cavity (GC), to emphasize its clinical importance, and compare it with the previous studies. Material and Methods: This study was performed with 157 (78 right sides, 79 left sides) adult Anatolian dry scapulae. The GCs were typed as oval, pear, and inverted comma shaped and noted the number of GC notch. Results: The most common GC shape was found as the pear shaped with 63 (80.8%) at the right side, 49 (62%) at the left side, and 112 (71.4%) in total. The second most common GC shape was found as oval shaped with 13 (16.6%) at the right side, 28 (35.5%) at the left side, and 41 (26.1%) in total. The glenoid notch was found at the right side, left side, and totally; 28 (35.9%), 19 (24.1%), and 47 (29.9%), respectively. All of the inverted comma shaped GCs had distinct glenoid notch, while the oval shaped GCs not. The pear shaped GCs had indistinct glenoid notch or no glenoid notch. The glenoid notch was found at the right side, left side, and totally on the pear shaped GC; 26 (41.3%), 17 (34.7%), and 43 (38.4%), respectively. Conclusion: Pear shaped GC was found as the most (71.4%) common shape in this study. Forty-seven (29.9%) of the scapulae had a glenoid notch. The notch and shape variations of the GC are important and this study will contribute to anatomists, orthopedists, and radiologists from this perspective. [ABSTRACT FROM AUTHOR]

Abstract Background This study aimed to investigate the three-dimensional (3D) anatomical relationship between the suprascapular nerve and scapula, and the method of protecting the suprascapular nerve in reverse total shoulder arthroplasty (RTSA) Methods In the present study, 12 fresh adult cadaver shoulder specimens were dissected. X-ray and computed tomography (CT) were used to investigate the 3D scapular and suprascapular nerve images. Results The results revealed that the best fitting baseplate diameter was 24.73 ± 1.56 mm. Furthermore, the baseplate diameter correlated with the glenoid cavity width. After the osteotomy, a simulated screw placement on the baseplate was performed. The dangerous area for the posterior screw placement was at the angle between the upper edge and transverse axis exceeding 38° and between the lower edge and transverse axis exceeding 76°. The distance between the nearest point of the nerve and osteotomy plane was 15.38 ± 2.02 mm, and the angle between the projection point of the nearest point and transverse axis was 27.33 ± 7.96°, which was the dangerous area for retractor placement. The suitable angle between the superior screw and longitudinal axis was 21.67 ± 13.27°, and the suitable superior screw length was 34.66 ± 2.41 mm. Conclusion In RTSA, the baseplate size correlates with the glenoid cavity width. The relationship between the screw and suprascapular nerve and retractor placement position should be carefully considered to avoid damaging the suprascapular nerve.

Background: The glenopolar angle (GPA), usually ranges from 30° to 45°. GPA measures the tilt of the plane of the glenoid cavity in relation to the axis of the body of the scapula passing from the superior pole of the glenoid cavity to the inferior angle of the scapula. It is essential to assess the results of surgeries for dislocated shoulders. Worse long-term outcomes can arise from glenoid misalignment in scapular neck fractures. When evaluating prognosis and planning therapy for shoulder injuries including scapular fractures, GPA assessment is essential. Still, there is a dearth of data on the normal range of GPA and its contributing elements, which calls for more study. The purpose of this study is to determine typical GPA values by utilizing radiographs and a sizable sample of scapular bone specimens., Methods: In this study, the GPA was assessed in 50 chest radiographs of anteroposterior (AP) view and Neer's view of individuals as well as 100 dried scapulae of any gender. The mean GPA obtained using the various methods was then statistically compared., Findings: All scapulae had an average GPA of 42.6°. Twenty-nine scapulae had GPA observations higher than 45°, with an average of 47.2°. Twenty-seven scapulae had GPA measurements below 40°, averaging 37.3°. Right-sided 62 scapulae with an average GPA of 43.1° were present. Thirty-eight of left-side scapulae had a GPA of 41.7° on average. It was determined that the 1.6° mean difference in GPA between the two groups was not statistically significant. The Kolmogorov-Smirnov test verified that the GPA data had a normal distribution. The homogeneity of variances across various measuring techniques was confirmed using Levene's test. The average GPA measured using the dry scapula approach was 42.6°, the average GPA measured using the AP view was 39.8°, and the average GPA measured using the Neer I view was 42.3°. The GPA means from these three approaches differed considerably (p=0.0014) according to a one-way Analysis of Variance (ANOVA). Fisher's least significant difference post hoc testing showed that the scapular bone specimens and the Neer I view revealed significantly higher GPA values than AP shoulder radiographs. The GPA values obtained from the osteological group and the Neer I perspective had a mean difference of 0.21°, which was practically identical and suggested that there was no statistically significant difference between these approaches., In Summary: In order to diagnose and treat a variety of shoulder joint diseases, this study estimates the normal values of scapular GPA. Furthermore, it offers support for improved implant design in the context of Indian shoulder joint replacement and repair. Using every measurement technique, the GPA values on the right and left sides did not differ significantly. GPA results from various measuring methods varied significantly, which emphasizes the significance of methodological consistency in clinical and research settings., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Institutional Ethical Committee issued approval 604/IEC/IGIMS dated 18/12/2018. I hereby affirm that the Institutional Ethical Committee or Ethics Committee has approved the research conducted for this article. The protocols and methodologies employed in this study have been carefully reviewed and deemed ethically sound in accordance with the established guidelines and regulations. Furthermore, all necessary permissions and consent procedures have been obtained from relevant participants or stakeholders involved in this research. The confidentiality and anonymity of participants have been rigorously maintained, and their rights and welfare have been upheld throughout the course of this study. This statement affirms the ethical integrity and compliance of the research conducted upholding the highest standards of ethical conduct. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Kumari et al.)

Introduction: Scapula is a flat triangular bone that situates at the posterior wall of the thorax and composes the shoulder joint. On its lateral angle, there is an opening called glenoid cavity which morphology varies between individuals, contributing to shoulder lesions, surgical access and the selection of prostheses. Material and Methods: A total of 116 dried human adult scapulae localized in the Northeast of Brazil were analyzed. The shape of the glenoid cavity was evaluated, and linear measurements of the scapulas and glenoid cavity were taken to estimate the total size. Values of p=0.05 were considered significant. Results: The most frequent shape of glenoid cavity was inverted comma-shaped, with 63 scapulae (54.3%). The mean value of the SI diameter was 36.85±0.36 mm for the right side, and 36.32±0.34 mm for the left side. The mean value of the AP1 diameter was 26.00±0.33 mm for the right side and 26.64±0.32 mm for the left side. For the AP2 diameter, the values were 18.27±0.36 mm for the right side and 18.22±0.55 mm for the left side. The right and left glenoid cavity index were 0.48±0.008% and 0.47±0.01%, respectively. The value for MSL was 171.3±22.64 mm for the right side and 172.6±23.68 mm for the left side. While the value for MSB was 100.8±0.86 mm for the right side and 103.5±0.90 mm for the left side. Conclusion: For the first time a study describing the scapular morphometry was developed on Northeastern Brazil. The findings contriutes for understanding the ethnicity role on scapular morphology variation. [ABSTRACT FROM AUTHOR]

Background and aims: Glenoid cavity of scapula is known for its variable morphology. The variations in the shape of glenoid cavity are due to the presence of a notch in its antero-superior part. The glenoid cavity is small and allows only a limited area for fixation devices. Knowledge of its morphology and dimensions would help in designing shoulder prosthesis for shoulder arthroplasty. Aim of current study is to determine the metrical and morphological variations [variation of shapes] of the glenoid cavity of the scapula for a better understanding and management of shoulder pathology. Materials and Method: One hundred dry scapulae of unknown sex availed from the Department of Anatomy, Mysore Medical College were studied. Varying shape of glenoid cavity based on presence of notch was also noted and measurements were taken with the digital Vernier caliper. Results: The glenoid cavity was found to occur in pear, oval, inverted comma shapes in frequency of 65.3%, 28.8%, 5.7% on right side and 62.2%, 27%, 10% on left side respectively. The mean anteroposterior diameter 1 and 2 were 24.05 ± 2.79 mm and 18.31 ± 2.36mm respectively. The mean Glenoid cavity index was 68.05 ± 4.87mm. Conclusion: The findings of the present study concurs with other studies, although there is slight difference in frequency of occurrence of shape of glenoid cavity which could be explained on the basis of ethnic and racial basis. The sound knowledge of various parameters of the glenoid cavity is important while performing shoulder arthroplasty and designing glenoid prostheses

Total shoulder arthroplasty (TSA) is commonly performed for shoulder osteoarthritis (OA). Uncemented metal-backed (MB) glenoid components were introduced in an attempt to avoid glenoid loosening. New Zealand and Australian Joint Registry studies have shown significantly higher revision rates when uncemented MB glenoids are used. We used the New Zealand Joint Registry (NZJR) to compare all-cause revision rates and functional scores for TSA and investigated the trends of glenoid fixation used in New Zealand. The NZJR was accessed for all primary TSA undertaken for OA from January 2000 to December 2017. Patient demographics were collated. All-cause revision rates were reported as rate per 100 component-years. Analysis was repeated excluding the uncemented SMR L2 glenoid (LimaCorporate), as it was a potential confounder. Kaplan-Meier survival analysis was performed. Oxford Shoulder Scores at both 6 months and 5 years were analyzed. A total of 2613 TSAs were performed for OA during the study period, representing 85.0% of all TSAs in New Zealand. Overall, 62.1% of the patients were female. In addition, 69.6% of glenoids were cemented and 30.4% uncemented. The most common uncemented MB glenoid was SMR 86.6% (LimaCorporate), and cemented was Global (DePuy) 49.8%. The revision rate for TSA with uncemented glenoids was significantly higher at 2.03 compared with cemented at 0.41 per 100 component-years (P <.001). Hazard ratio 5.0 for revision of uncemented glenoids. No significant difference was found in Oxford Scores at 6 months (39.7 vs. 40.3, P =.13) or 5 years (42.1 vs. 42.8, P =.22). The most common mode of failure was glenoid loosening in cemented glenoids (44.4%), and component failure in uncemented (34.8%). Revision for rotator cuff, deep infection, and instability were comparable between groups. When excluding SMR L2, uncemented MB glenoid all-cause revision rates remained significantly higher than cemented (1.42 vs. 0.41 per 100 component-years, P <.001). SMR L1 uncemented MB glenoids had a higher revision rate than the non-SMR uncemented glenoids (1.61 vs. 0.18 per 100 component-years, P =.009). Uncemented glenoid use peaked in New Zealand in 2011 at 46.7% of TSAs but declined to 20.1% in 2017. In the NZJR, primary TSAs undertaken for OA have a significantly higher all-cause revision rate when the glenoid component is uncemented. Uncemented glenoids have a 5.0 times higher revision rate. Excluding SMR L2 glenoids from the analysis, the significantly higher revision rate remained for uncemented glenoids. These data reaffirm that uncemented MB glenoids are associated with higher revision rates. [ABSTRACT FROM AUTHOR]

Glenoid morphology is a key factor in determining the success of shoulder surgery. The purpose of this experimental study was to precisely determine the anatomical size and orientation of the glenoid in the Chilean population. 122 CT scans from asymptomatic Chilean patients were obtained. The mean age was 43.8 years (SD 12.3; range, 17-53 years) with 63 female and 59 male patients. For each of the scapulae, were obtained the glenoid version and inclination, maximum glenoid width and height, superior glenoid width, glenoid surface area, glenoid vault depth, and maximum scapular width. The glenoid size showed an average width of 26 ± 2.7 mm, a height of 40.3 ± 3.5 mm and a vault depth of 26.5 ± 3.7 mm. There were significant differences between men and women. The glenoid orientation showed an average of -13.9 ± 4.8° of retroversion and a superior inclination of 11.1 ± 4.7°. Significant differences between men and women were seen only for version. We conclude, that in this Chilean sample the morphological parameters of the glenoid correspond to the published literature, however, some characteristics in this cohort must be further confirmed using other methods. [ABSTRACT FROM AUTHOR]

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Introduction: Glenoid fossa of scapula articulates with the head of humerus and forms gleno-humeral joint (shoulder Joint). So, the knowledge of various shapes and size of glenoid fossa is useful to clinician for better understanding of various diseases associated with the joint and also helpful to orthropaedician to choose the right prosthesis for shoulder replacement surgeries. Aim: To observe the shape and to measure the various diameters of glenoid fossa in adult dry human scapulae. Materials and Methods: Total of 100 dry adult human scapulae of unknown sex and age were obtained from the museum of anatomy and forensic medicine and were included in present study. Out of total 100 scapulae, 56 were of right side and 44 were of left side. Various shapes of glenoid fossa were observed on the basis of presence or absence of notch. Morphometric parameters such as Superio-Inferior Diameter (SI), Anterio-Posterior Diameter-1 (AP-1) and Anterio-Posterior Diameter-2 (AP-2) were measured by digital Vernier caliper. All the parameters were tabulated and analysed statistically. Results: In the present study most common shape of glenoid fossa was Pear shape that is 44% (42.9% on right, 45.5% on left), followed by oval shape in 34% (35.7% on right, 31.8% on left side) and inverted comma shape in 22% scapulae (21.4% on right side, 22.7% on left side). The mean measured values in total scapulae were; SI diameter was 34.24±3.27 mm, AP-1 diameter was 23.93±2.67 mm, AP-2 diameter was 12.96±1.84 mm and glenoid cavity index was 70.12±7.13 mm. Conclusion: Morphological and Morphometric analysis of glenod fossa of scapula help clinicians and orthropaedicians in shoulder arthroplasty and its associated shoulder diseases.

Objective  This study assesses the relationship between the glenoid bone loss size and range of motion, functional outcomes, and complications in high-performance athletes undergoing bone block surgery for anterior shoulder instability. Methods  This retrospective study evaluated postoperative outcomes in athletes submitted to bone block surgery for anterior shoulder instability. In 5 years, 41 shoulders underwent the procedure; 20 had bone losses up to 15%, and 21 shoulders presented bone losses ranging from 15% and 25%. Results  There was no statistically significant difference regarding postoperative complications, new dislocations, and the rate of return to sports. In addition, the quantitative criteria evaluated, i.e., ranges of motion and functional scores, showed no statistically significant difference between groups. Conclusion The size of the bone loss per se does not seem to affect functional outcomes and complications from these procedures, which are safe techniques for small and large bone losses., Competing Interests: Conflito de Interesses Os autores declaram não haver conflito de interesses., (Sociedade Brasileira de Ortopedia e Traumatologia. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)

Many of the squirrel-related rodents (i.e., Sciuromorpha) are tree-dwelling species known to be very agile climbers. This taxon also includes the most diverse clade of gliding (aerial) mammals that likely descended from a non-gliding arboreal ancestor and evolved a patagium (i.e., a gliding membrane) to increase gliding performance. Glides can cover distances of up to 150 m and landing is typically accomplished by stalling the patagium to reduce impact velocity. It remains unclear if this behavior suffices to keep stresses on the locomotor apparatus similar to those experienced by their arboreal relatives or whether gliding behavior increases landing forces and stresses. The sparsely available support reaction force data are ambiguous, but bone microstructure is highly adaptable to changes in loading regime and likely provides insights into this question. Using μCT scans, we compared the cortical thickness of the glenoid fossa of the shoulder joint between arboreal and aerial Sciuromorpha using evolutionary model comparison, while also accounting for regional differences of the glenoid fossa. We did not find any differences between these locomotor behaviors, irrespective of the glenoid region. These findings agree with previous analyses of the microstructure of the femur in Sciuromorpha. We discuss different aspects that could explain the similarity in cortical thickness. According to our analysis of glenoid cortical thickness the loading regime appears not to have changed after the evolution of gliding locomotion, likely due to adjustments in landing performance., (© 2022 The Authors. The Anatomical Record published by Wiley Periodicals LLC on behalf of American Association for Anatomy.)

The aim of this study was to evaluate and compare the morphology and dimensions of glenoid cavity and examine their relationship with body size and locomotion efficiency. The study was performed on 356 glenoid cavities from 178 mammals, representatives of all major taxa from rodents, sirenians, marsupials, pilosa, cetaceans, carnivores, ungulates, primates and apes. Parameters measured included cranio-caudal and lateral-medial diameters and their ratios; areas of articular surfaces; glenoid cavity index; angles-alpha, -beta and -gamma and length of supraglenoid tubercle and coracoid process. Images were taken using computed tomographic (CT) scanning technology (CT-Aquarium, Toshiba and micro CT- LaTheta, Hotachi, Japan) and measurement values were acquired and processed using Avizo computer software and CanvasTM 11 ACD systems. Statistical analysis was performed using Microsoft Excel 2013. Results obtained showed that mammals exhibit various patterns in the morphology of glenoid cavities that may be associated with adaptation of the glenohumeral joint to robust mobility for locomotion. When the diameters of glenoid cavities were compared between groups of mammals, significant difference was observed in diameters of articular surfaces between rodents and ungulates (1.34±0.32); carnivores and primates (1.39±0.16); primates and rodents and carnivores (1.3±0.12) and between ungulate and carnivores, rodents and primates (1.19±0.18). The mean values of glenoid cavity index in ungulates were found to be lower (0.15±0.13) than those of carnivores (0.22±0.71) and apes (0.26±0.16), indicating that the depth of glenoid cavities of ungulates is shallow compared to those of carnivores and apes. The inclination of the scapula relative to the trunk was found to be tilted lateromedially in apes; mediolaterally in primates (monkeys); craniocaudally in carnivores; vertically in ungulates and cranially in diggers. Significantly, the angles were wider in apes but narrower in ungulates. The length of supraglenoid tubercle was long in ungulates but short in carnivores while the coracoids process was short in ungulates but long in primates and moderately in carnivores and other mammals. The morphological characteristics of the glenoid cavities and the functional interpretation of the parameters in mammals are discussed in detail. [ABSTRACT FROM AUTHOR]

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Structural arrangements of the bony microstructure of a joint through adaptational processes are thought to be determined by the biomechanical demands and its changes. Pursuing this theory of "form follows the biomechanical function", the load distribution of the glenoid cavity, as it is mirrored in its mineralization pattern, should link not only to its thickness distribution, but also will have an impact onto the trabecular network below. To prove and confirm this hypothesis, we analysed the mineral distribution in correlation to the subchondral bone plates thickness and the distribution of architectural parameters of the trabecular network below. Our findings clearly state an inhomogeneous but regular and reproducible mineral distribution pattern in respect to the biomechanical demands and a thickness of the subchondral bone plate which shows a significant correlation (78-93%). As for the trabecular network below, the distribution of the analysed parameters also revealed an inhomogeneous distribution with a regular pattern in correlation to the biomechanical impact. We found distinctive maxima of material distribution and stability (bone volume 79%, plate-like architecture 77%) situated below areas of high long-term load intake. With increasing depth, the trabecular network administers the expression of each structural parameter following the fact that the strain energy gets more and more evenly distributed and changes from a high degree of differentiation just beneath the SBP to a more equal distribution within the deeper areas. After all, the biomechanical situation of a joint directly influences the bony formation of the subchondral bone plate and the trabecular network below. [ABSTRACT FROM AUTHOR]

Objective: The glenopolar angle is a helpful criterion for recommending operative treatment. This study aims to determine the morphometric features of the scapula and provide essential information that supplies scapular biomechanics to produce a formula., Methods: The study was carried out on 34 dry scapulae in the laboratory of the Anatomy Department of the Faculty of Medicine, Bursa Uludag University. We used calipers for the linear measurements and the ImageJ program for the area and angle parameters. A total of 23 parameters were evaluated in the study. Statistical analyzes were performed using SPSS 22.0 software., Results: According to the results of the correlation analysis, the highest correlation value of (R=0.957) was found to be the distance between the superior angle (angulus superior)-top of the glenoid plane and the inferior angle (angulus inferior)-the top of the glenoid plane. To estimate the glenopolar angle, we applied linear regression analysis and developed the following formula: Glenopolar angle =115.589 - (6.401 x the distance between the coracoid process and the top of the glenoid cavity) - (0.368 x angle between the glenoid plane and the lateral edge of the scapula extending towards the endpoint of the glenoid plane) (Adjusted R 2 =0.667)., Conclusions: Glenopolar angle can provide information about the fracture risk of the glenoid cavity and allows orthopedic surgeons to make quick decisions about the risk in the region. We believe that the study will provide a different perspective on designing different products in industrial designs for shoulder joints, especially in implantations., Competing Interests: Conflict of Interest: The authors have no conflict of interest to declare., (©Copyright 2023 by the Istanbul Medeniyet University / Medeniyet Medical Journal published by Galenos Publishing House.)

Objective: A complete understanding of the glenohumeral joint anatomy is crucial for osteochondral allograft (OCA) transplantation and prosthetic design. However, existing data on the cartilage thickness distribution are not consistent. This study aims to describe the cartilage thickness distribution at both the glenoid cavity and humeral head in males and females., Design: Sixteen fresh cadaveric shoulder specimens were dissected and separated to expose the glenoid and humeral head articular surfaces. The glenoid and humeral head were cut into 5-mm coronal sections. Sections were imaged and cartilage thickness was measured at 5 standardized points on each section. Measurements were analyzed based on age, sex, and regional location., Results: For the humeral head, cartilage was thickest centrally (M = 1.77 ± 0.35 mm) and thinnest superiorly and inferiorly (M = 1.42 ± 0.37 mm, 1.42 ± 0.29 mm). At the glenoid cavity, cartilage was thickest in the superior and inferior areas (M = 2.61 ± 0.47 mm, 2.53 ± 0.58 mm) and thinnest centrally (M = 1.69 ± 0.22 mm). Males were found to have thicker cartilage at both the humeral head and glenoid ( P = 0.0014, P = 0.0133)., Conclusions: Articular cartilage thickness distribution of the glenoid and humeral head is nonuniform and reciprocal in nature. These results can be used to further inform prosthetic design and OCA transplantation. We noted a significant difference in cartilage thickness between males and females. This suggests that the sex of the patient should be taken into consideration when matching donors for OCA transplantation.

Background Glenoid loosening is a common mode of failure after total shoulder arthroplasty (TSA). Newer cementless glenoid components have been introduced to promote biological fixation with the aim to decrease glenoid loosening. Limited data are available comparing revision rates between cemented and cementless glenoid fixation in TSA. The study aim was to compare the revision rates of cemented and cementless design glenoid components used in conventional TSA performed for the diagnosis of osteoarthritis. The secondary aim was to compare various subclasses of glenoid components. Methods Data were obtained between April 16, 2004, and December 31, 2016, from the Australian Orthopaedic Association National Joint Replacement Registry. Within the study period, 10,805 primary conventional TSAs were identified. The analysis was undertaken for the diagnosis of osteoarthritis, which represented 95.8% of all conventional TSA procedures. Results At 5 years, in patients with primary TSA procedures, those with cemented glenoids had a lower revision rate than those with cementless glenoids: 3.7% versus 17.9% (hazard ratio for entire period, 4.77). The most common revision diagnosis for primary conventional TSA with cementless glenoid fixation was rotator cuff insufficiency (4.4% for cementless vs 0.4% for cemented), instability and/or dislocation (3.8% for cementless vs 0.8% for cemented), and loosening and/or lysis (1.1% for cementless vs 1.1% for cemented). Conclusions Cementless glenoid components in conventional TSA had a significantly higher revision rate than cemented glenoid components. The loosening rates between cemented and cementless glenoid components were similar. Glenoid design and fixation are important considerations when selecting a prosthesis for TSA. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to assess condylar resorption, spatial change in glenoid cavity, and its risk factors after mandibular advancement by three-dimensional volumetric analysis. Subjects consisted of 30 condyles of 15 patients diagnosed with mandibular retrognathism who underwent Le Fort I and bilateral sagittal split ramus osteotomy advancement. CBCT images were taken before surgery (T0), immediately after surgery (T1), and postoperatively at 6 months (T2) and 1 year (T3). Condylar resorption was observed in 21 condyles. The posterior was the most affected region, while the anterior was the least affected. The volume of the glenoid cavity was significantly increased after surgery regardless of the presence or absence of resorption. However, the cavity recovered close to its original volume over time. At 1 year after surgery, the volume was not significantly different from the preoperative volume. Counterclockwise rotation of the proximal segment was found to be a risk factor affecting resorption based on correlation analysis. Mandibular advancement appeared to generate excessive mechanical stress on the posterior condyle, and might be responsible for the resorption. Counterclockwise rotation might have added stress to the region. Articular spatial change was transient and did not appear to be related to condyle resorption. [ABSTRACT FROM AUTHOR]