A Morphometric Study of Glenoid Cavity of Scapula in Bangladeshi Population.

This cross-sectional descriptive purposive study was conducted among 150 (70 right and 80 left) fully ossified dry human scapulae of Bangladeshi people from January 2019 to December 2019 in the Department of Anatomy, Mymensingh Medical College, Mymensingh. Shape of the glenoid cavity was observed as pear, oval or inverted comma shape. Morphometric parameters such as length and breadth of glenoid cavity were measured by digital Vernier slide calipers. In this study, 19.13% cases were found inverted comma shaped, 35.65% cases were oval and 45.22% cases were pear shaped. The mean±SD length of glenoid cavity was 37.5±3.61 mm and 36.19±3.68 mm on right and left sided scapulae respectively and mean±SD breadth was 23.6±2.73 mm on right and 23.42±2.75 mm on left side respectively. Mean±SD glenoid cavity index was 62.89±4.39 on right and 64.61±4.74 on left sided scapulae. Morphometric analysis of glenoid fossa of scapula might help clinicians in shoulder and its associated diseases.

Morphological classification and measurement of the glenoid cavity using three-dimensional reconstruction in a Chinese population.

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.

Sex determination from glenoid cavity by computed tomography in Turkish population / Determinación del sexo de la cavidad glenoidea mediante tomografía computarizada en la población turca

SUMMARY: 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.

RESUMEN: El objetivo de este estudio fue contribuir a la determinación del sexo a partir de la escápula en la población turca y comparar con estudios previos. Esta investigación se realizó con 200 escápulas (100 hombres y 100 mujeres). El rango de edad de los pacientes estaba entre de 18 años y 93 años. Escaner de tomografía computada se usó para medir en la cavidad glenoidea los siguientes parámetros: longitud (LCG), ancho (ACG), profundidad (PCG), perímetro (PG) y volumen (VCG). Se midieron 20 escápulas seleccionadas tres veces al azar para examinar la confiabilidad intraevaluador de estas mediciones. Se realizó un análisis de regresión logística de género para encontrar las variables significativas en la determinación del sexo a partir de la escápula. El parámetro más eficaz para determinar el sexo a partir de la escápula resultó ser VCG (88,5%). Los efectos de LCG, PG, ACG y PCG en la determinación del sexo a partir de la escápula fueron del 83 %, 82,5 %, 79,5 % y 66 %, respectivamente. La combinación de VCG y PG (89,5%) resultó ser la combinación más efectiva en la determinación del sexo a partir de la escápula. Se encontró que los valores de correlación intraclase de todas las mediciones tenían una alta confiabilidad. De acuerdo con la literatura, PG y PCG junto con el VCG en la población turca, no se han utilizado previamente para la determinación del sexo a partir de la escápula. Se determinó que una combinación de VCG y PG son los parámetros más efectivos en la determinación del sexo a partir de la escápula. Existe escasa información sobre la determinación del sexo a partir de la escápula en la población turca. Este estudio guiará a los antropólogos, forenses y anatomistas en los estudios de determinación del sexo de la escápula y sera útil para los cirujanos en situaciones clínicas relacionadas con la escápula.

Estimating glenoid fossa width for instability - related bone loss with CT scan in a Chilean sample / Estimación del ancho de la fosa glenoidea para la pérdida ósea relacionada con inestabilidad con tomografía computarizada en una muestra chilena

SUMMARY: Glenoid fossa bone loss has been associated with recurrence and failure after glenoid labrum repair for shoulder instability. Quantification of glenoid fossa bone loss is critical for the successful treatment of glenohumeral instability. The aim of this paper was to estimate a linear regression model based on glenoid height in CT scan adjusted for age and sex to calculate glenoid fossa width in a healthy Chilean sample. CT scans of 101 shoulders were reviewed. The mean age was 51.96 years (SD 19.16; range, 15-88 years) with 53 females and 48 male patients. Studies with signs of bone loss, instability, fracture, or arthritis were excluded. After 3D-CT reconstruction, the height and width of each glenoid fossa was measured using the Owens methodology. All landmarks for the 2 measurements were placed on the most lateral surface of the glenoid fossa margin. Measurements for all shoulders were recorded by 3 observers and repeated on a subset (n = 20) of shoulders, under blinded conditions, by the same observer, at least 2 weeks after the initial measurements. Descriptive statistics, intraclass correlation and regression coefficients were calculated with Stata BE 17® software. A p- value of 0.05 was considered significant. A linear regression model was estimated resulting in the formula "Width = 10.97 + 0.02 * Age + 0.41 * Height - 1.95 * Sex (1=Female, 0=Male)". This model presented all coefficients with p <0.05 and an adjusted R2 of 0.73. Furthermore, it fulfilled the assumption of linearity, normal distribution of errors, independence of errors, and homoscedasticity. Regarding the intraobserver correlation, ICC was 0.76 for height and 0.91 for width; the interobserver ICC was 0.93 for height and 0.86 for width. A 3D-CT specific formula was developed to predict glenoid fossa width based on height with sufficient accuracy to be clinically valuable.

RESUMEN: La pérdida de hueso de la fosa glenoidea se ha asociado con recurrencia y falla después de la reparación del labrum glenoideo por inestabilidad del hombro. La cuantificación de la pérdida ósea glenoidea es fundamental para el tratamiento exitoso de la inestabilidad glenohumeral. El objetivo de este trabajo fue estimar un modelo de regresión lineal basado en la altura glenoidea en una tomografía computarizada ajustada por edad y sexo para calcular el ancho de la fosa glenoidea en una muestra chilena sana. Se revisaron las tomografías computarizadas de 101 hombros. La edad media fue de 51,96 años (DE 19,16; rango, 15- 88 años) con 53 mujeres y 48 hombres. Se excluyeron los estudios con signos de pérdida ósea, inestabilidad, fractura o artritis. Después de la reconstrucción 3D-CT, se midió la altura y el ancho de cada fosa glenoidea utilizando la metodología de Owens. Todos los puntos de referencia para las 2 mediciones se colocaron en la superficie más lateral del margen glenoideo. Las mediciones de todos los hombros fueron registradas por 3 observadores y repetidas en un subconjunto (n = 20) de hombros, en condiciones ciegas, por el mismo observador, al menos 2 semanas después de las mediciones iniciales. La estadística descriptiva, la correlación intraclase y los coeficientes de regresión se calcularon con el software Stata BE 17®. Se consideró significativo un valor de p de 0,05. Se estimó un modelo de regresión lineal que resultó en la fórmula "Ancho = 10,97 + 0,02 * Edad + 0,41 * Altura - 1,95 * Sexo (1 = Mujer, 0 = Hombre)". Este modelo presentó todos los coeficientes con p <0.05 y un R2 ajustado de 0.73. Además, cumplió con los supuestos de linealidad, distribución normal de errores, independencia de errores y homocedasticidad. En cuanto a la correlación intraobservador, el CCI fue de 0,76 para la altura y 0,91 para la anchura; el ICC interobservador fue de 0,93 para la altura y 0,86 para la anchura. Se desarrolló una fórmula específica de 3D-CT para predecir el ancho glenoideo en función de la altura con suficiente precisión para ser clínicamente valiosa.

Glenoid size and orientation in the Chilean population / Tamaño y orientación glenoidea en la población chilena

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.

La morfología glenoidea es un factor clave para determinar el éxito de la cirugía de hombro. El propósito de este estudio experimental fue determinar con precisión el tamaño anatómico y la orientación de la glenoides en la población chilena. Se obtuvieron 122 tomografías computarizadas de pacientes chilenos asintomáticos. La edad media fue de 43,8 años (DE 12,3; rango, 17-53 años) con 63 pacientes femeninos y 59 masculinos. Para cada una de las escápulas, se obtuvieron la versión glenoidea y la inclinación, el ancho y la altura glenoidea máxima, el ancho glenoideo superior, el área de superficie glenoidea, la profundidad de la bóveda glenoidea y el ancho escapular máximo. El tamaño glenoideo mostró un ancho promedio de 26 ± 2,7 mm, una altura de 40,3 ± 3,5 mm y una profundidad de bóveda de 26,5 ± 3,7 mm. Hubo diferencias significativas entre hombres y mujeres. La orientación glenoidea mostró un promedio de -13,9 ± 4,8 ° de retroversión y una inclinación superior de 11,1 ± 4,7 °. Se observaron diferencias significativas entre hombres y mujeres solo para la versión. Concluimos que en esta muestra chilena los parámetros morfológicos de la glenoides corresponden a la literatura publicada, sin embargo, algunas características de esta cohorte deben confirmarse aún más utilizando otros métodos.

Anatomic shoulder parameters and their relationship to the presence of degenerative rotator cuff tears and glenohumeral osteoarthritis: a systematic review and meta-analysis.

BACKGROUND: Scapular anatomy, as measured by the acromial index (AI), critical shoulder angle (CSA), lateral acromial angle (LAA), and glenoid inclination (GI), has emerged as a possible contributor to the development of degenerative shoulder conditions such as rotator cuff tears and glenohumeral osteoarthritis. The purpose of this study was to investigate the published literature on influences of scapular morphology on the development of degenerative shoulder conditions. METHODS: A systematic review of the Embase and PubMed databases was performed to identify published studies on the potential influence of scapular bony morphology on the development of degenerative rotator cuff tears and glenohumeral osteoarthritis. The studies were reviewed by 2 authors. The findings were summarized for various anatomic parameters. A meta-analysis was completed for parameters reported in more than 5 related publications. RESULTS: A total of 660 unique titles and 55 potentially relevant abstracts were reviewed with 30 published articles identified for inclusion. The AI, CSA, LAA, and GI were the most commonly reported bony measurements. Increased CSA and AI correlated with rotator cuff tears, whereas lower CSA appeared to be related to the presence of glenohumeral osteoarthritis. Decreased LAA correlated with degenerative rotator cuff tears. Five articles reported on the GI with mixed results on shoulder pathology. DISCUSSION: Degenerative rotator cuff tears appear to be significantly associated with the AI, CSA, and LAA. There does not appear to be a significant relationship between the included shoulder parameters and the development of osteoarthritis.

[The age-specific changes in the glenoid cavity of scapula]. / Vozrastnye izmeneniia sustavnoi vpadiny lopatki.

The objective of the present study was to develop the diagnostic criteria for the medical criminalistic identification of the age group of the subjects based on the age-specific changes in the glenoid cavity of scapula. A total of 108 scapulae were available for the examination; they were obtained from the persons at the age between 19 and 99 years who had died from cardiovascular diseases, acute intoxication with ethanol and/or narcotic drugs, and a combined mechanical injury. The morphological, osteometric, and statistical methods were used. The data obtained made it possible to propose the morphological criteria that might be instrumental in decreasing the number of osteological studies and thereby reducing the financial burden associated with morphological studies of the skeleton. Moreover, they are likely to increase the evidentiary value of the expert conclusions.

Anthropometrical study of the human glenoid in a normal Spanish population. / Estudio antropométrico de la glena humana en una población española normal.

OBJECTIVE: To evaluate the size of the glenoid in a southern Spanish population, to compare it with previous results from other populations and determine the size of the implants that are marketed for shoulder arthroplasty. MATERIAL AND METHODS: Between January 2015 and December 2017, an anthropometrical study of the human glenoid was performed using computed axial tomography scans (CT) of 154 patients over 30 years old. The glenoid dimensions were analysed 3-dimensionally using 2mm interval thicknesses, determining the average height and width of the glenoid. The upper point of the glenoid geometry was determined as the supraglenoid tubercle of the ovoid glenoid surface, where the long head of the biceps tendon is thought to originate. The lower point was then positioned at the furthest point from the upper point on the glenoid contour. Anterior and posterior points were determined such that the 3-dimensional anterior-posterior distance was maximized on the plane perpendicular to the upper-lower axis. Sex differences and correlations between sides and among the respective parameters in the glenohumeral dimensions were also evaluated. RESULTS: The glenoid had an average height of 28.78mm and width of 20.27mm. The values were significantly different between the men and the women, being greater in the men. The glenoid size is well correlated with the patient's size. Direct correlations exist between the glenoid height and width and the glenoid size and the patient's height. The available metaglenoids currently on the market are no bigger than 25-24mm. CONCLUSION: In comparison, the southern Spanish population have a glenoid size similar to the Caucasian population, but smaller than that of the American population. The data shown could be useful to improve the design of shoulder prostheses for the southern Spanish population.

Predetermining glenoid dimensions using the scapular dimensions.

BACKGROUND: Variations of morphology of the glenoid cavity have been previously reported. These influence the surgical reconstruction or arthroplasty of the shoulder. This study aims to study the variation of the shape of suprascapular notch, shape of glenoid cavity, dimensions of both the scapular and the glenoid cavity, and predict the glenoid dimensions from the scapular dimension parameters. MATERIALS AND METHODS: Adult-dried scapulae were collected. The shapes of each suprascapular notch and glenoid cavity were evaluated. The scapular height, scapular width, glenoid superoinferior distance, and glenoid anteroposterior distance were measured using a digital vernier caliper, and statistical analysis was conducted on the data that were obtained. RESULTS: There were 264 scapulae included in this study (166 male and 98 female). Most of the glenoid cavities were pear shaped (69.7%). The two most common types of suprascapular notches were small depression notches (31.8%) and the absence of notches (25.8%). The mean ± SD of scapular height, scapular width, glenoid superoinferior distance, and glenoid anteroposterior distance were 148.2 ± 10.0, 108.1 ± 6.4, 37.1 ± 2.2, and 27.4 ± 2.1 mm, respectively, in the male samples and 133.0 ± 7.0, 97.0 ± 5.2, 33.2 ± 1.9, and 23.7 ± 1.7 mm, respectively, in the female samples. The male scapulae were significantly larger than the female scapulae (p value < 0.05). However, there were no differences between the male and female scapulae in terms of scapular index or glenoid index (p value > 0.05). Scapular height and width were significantly associated with both the glenoid superoinferior distance (p = 0.0001) and glenoid anteroposterior distance (p value = 0.0001). CONCLUSION: Scapular height and width can predict the dimensions of the glenoid. In cases of glenoid bone loss or shoulder arthroplasty, the native normal glenoid dimensions can be determined from the scapular dimensions as visualized using a true scapular anteroposterior radiograph. The surgeon can use these preoperative parameters when performing glenoid reconstruction or shoulder arthroplasty.

Tissue Engineering for the Temporomandibular Joint.

Tissue engineering potentially offers new treatments for disorders of the temporomandibular joint which frequently afflict patients. Damage or disease in this area adversely affects masticatory function and speaking, reducing patients' quality of life. Effective treatment options for patients suffering from severe temporomandibular joint disorders are in high demand because surgical options are restricted to removal of damaged tissue or complete replacement of the joint with prosthetics. Tissue engineering approaches for the temporomandibular joint are a promising alternative to the limited clinical treatment options. However, tissue engineering is still a developing field and only in its formative years for the temporomandibular joint. This review outlines the anatomical and physiological characteristics of the temporomandibular joint, clinical management of temporomandibular joint disorder, and current perspectives in the tissue engineering approach for the temporomandibular joint disorder. The tissue engineering perspectives have been categorized according to the primary structures of the temporomandibular joint: the disc, the mandibular condyle, and the glenoid fossa. In each section, contemporary approaches in cellularization, growth factor selection, and scaffold fabrication strategies are reviewed in detail along with their achievements and challenges.

Can we use the contralateral glenoid cavity as a reference for the measurement of glenoid cavity bone loss in anterior shoulder instability?: a comparative analysis of 3D CT measurements in healthy subjects / ¿Podemos utilizar la cavidad glenoidea contralateral como referencia para la medición de la pérdida ósea de la cavidad glenoidea en la inestabilidad del hombro anterior?: un análisis comparativo de mediciones 3D TC en sujetos sanos

The purpose of this study was to compare the glenoid cavity measurements in healthy subjects. 100 adult subjects without shoulder pathology who had pulmonary computed tomography for any reason, were included in the study. Lung CT images were three-dimensionally rendered and glenoid cavity enface images were obtained. On these images, the glenoid cavity superior-inferior long axis and anterior-posterior equator, as well as the equatorial anterior and posterior radii, were measured. Dominant and nondominant glenoid cavity measurements were compared using the t-test in dependent groups. The long axis of the dominant glenoid cavity was 38.15 ± 3.5 mm, whereas it was 37.87 ± 3.3 mm on the non-dominant side (p = 0.068). The mean width of the glenoid cavity was 28.60 ± 3.3 mm in dominant glenoids cavities and 28.00 ± 2.9 mm in the non-dominant side (p = 0.0001). The equatorial anterior and posterior radii were significantly different between the two sides (p = 0.010, p = 0.001, respectively). The ratio of length to equator was different between the two sides (p = 0.012). The difference in equatorial lengths was 0.98 ± 0.8 mm (range, 0-4.2 mm). The mean difference between the long axis of the glenoid cavity was 1.2 ± 0.9 mm (range 0-4.6 mm). The equator on 69 individuals was larger on the dominant side. Glenoid cavity long axis was larger on the dominant side of 61 individuals. Glenoids cavities are not equal and not symmetrical to each other or influenced by hand dominancy. Measurements based on the assumption that both glenoids cavities are equal may be misleading.

El propósito de este estudio fue comparar las mediciones de las cavidades glenoideas en sujetos sanos. Se incluyeron en el estudio 100 sujetos adultos sin patología de hombro que tenían tomografía computarizada pulmonar. Las imágenes de CT de pulmón se representaron tridimensionalmente y se obtuvieron imágenes de la faceta de la cavidad glenoidea. En estas imágenes, se midieron el eje largo glenoideo superior e inferior y el ecuador anteroposterior, así como los radios ecuatoriales anterior y posterior. Las mediciones de las cavidades glenoideas dominantes y no dominantes se compararon usando la prueba t en grupos dependientes. El eje largo de la cavidad glenoidea dominante fue 38,15 ± 3,5 mm, mientras que fue 37,87 ± 3,3 mm en el lado no dominante (p = 0,068). El ancho medio de la cavidad glenoidea fue de 28,60 ± 3,3 mm en las glenoides dominantes y de 28,00 ± 2,9 mm en el lado no dominante (p=0,0001). Los radios ecuatoriales anterior y posterior fueron significativamente diferentes entre los dos lados (p=0,010; p=0,001, respectivamente). La relación de longitud al ecuador fue diferente entre los dos lados (p=0,012). La diferencia en las longitudes ecuatoriales fue de 0,98 ± 0,8 mm (rango, 0-4,2 mm). La diferencia media entre el eje largo de la cavidad glenoidea fue de 1,2 ± 0,9 mm (rango 0-4,6 mm). El ecuador en 69 individuos era más grande en el lado dominante. En 61 individuos el eje largo de cavidad glenoidea fue más grande en el lado dominante. Las cavidad glenoideas no son iguales ni simétricas entre sí ni están influenciadas por la dominancia de la mano. Las mediciones basadas en la suposición de que ambas cavidades glenoideas son iguales pueden ser engañosas.

Risk Factors and Outcomes of Revision Arthroscopic Posterior Shoulder Capsulolabral Repair.

BACKGROUND: Risk factors and outcomes of revision arthroscopic posterior capsulolabral repair of the shoulder are currently not well defined. HYPOTHESIS: Athletes who require revision arthroscopic posterior unidirectional capsulolabral repair will have poorer outcomes and return to play when compared with those undergoing primary procedures, with risk factors including younger age, injury size, bone loss, and anchor number. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A total of 297 shoulders that underwent arthroscopic posterior capsulolabral repair at minimum 2-year follow-up were reviewed. In addition to surgical data, the American Shoulder and Elbow Surgeons scoring system with subjective stability, range of motion, strength, and pain scores as well as return to sport were compared pre- and postoperatively between those who did and did not require revision surgery. Magnetic resonance arthrogram measurements of glenoid labral, chondral, and bone version and labral and bone width were also compared. RESULTS: Nineteen shoulders required revision surgery (6.4%) at 8.9-year follow-up. Significant risk factors included female sex ( P = .001), dominant shoulder ( P = .005), and concomitant rotator cuff injury ( P = .029). Patients with ≤3 anchors were more likely to require revision (odds ratio = 3.48). Smaller glenoid bone width was a risk factor for requiring future revision surgery ( P < .001), but glenoid labral, chondral, and bone version and labral width were not risk factors. All patients had significant improvements in American Shoulder and Elbow Surgeons, pain, range of motion, and strength scores after the original surgery; however, those who required revision surgery had less improvement ( P < .05). Stability improved significantly for nonrevisions ( P < .001) but did not for revisions ( P = .662). In the nonrevision group, 64.3% returned to sport at the same level, which was significantly higher than the 15.4% of the revision group ( P = .004). Overall, 78.6% of the nonrevision group and 61.6% of the revision group returned to sport at some level ( P = .280). CONCLUSION: Athletes underwent revision arthroscopic posterior capsulolabral repair at an incidence of 6.4%. Revision patients had significantly poorer outcome scores and return to play when compared with those who did not undergo revision surgery with risk factors being dominant shoulder surgery, female sex, concomitant rotator cuff injury, the use of 3 or fewer anchors, and smaller glenoid bone width. These data are essential for patient selection, optimal treatment techniques, and patient education as posterior shoulder instability failure requiring revision has not previously been evaluated.

A statistical shape model to predict the premorbid glenoid cavity.

BACKGROUND: This study proposes a method for inferring the premorbid glenoid shape and orientation of scapulae affected by glenohumeral osteoarthritis (OA) to inform restorative surgery. METHODS: A statistical shape model (SSM) built from 64 healthy scapulae was used to reconstruct the premorbid glenoid shape based on anatomic features that are considered unaffected by OA. First, the method was validated on healthy scapulae by quantifying the accuracy of the predicted shape in terms of surface distance, glenoid version, and inclination. The SSM-based reconstruction was then applied to 30 OA scapulae. Glenoid version and inclination were measured fully automatically and compared between the original OA glenoids, SSM-based glenoid reconstructions, and healthy scapulae. RESULTS: Validation on healthy scapulae showed a root-mean-square surface distance between original and predicted glenoids of 1.0 ± 0.2 mm. The prediction error was 2.3° ± 1.8° for glenoid version and 2.1° ± 2.0° for inclination. When applied to an OA dataset, SSM-based reconstruction restored average glenoid version and inclination to values similar to the healthy situation. No differences were observed between average orientation values measured on SSM-based reconstructed and healthy scapulae (P ≥ .10). However, the average orientation of the reconstructed premorbid glenoid differed from the average orientation of OA glenoids for Walch classes A1 (version) and B2 (version, inclination, and medialization). CONCLUSION: The proposed SSM can predict the premorbid glenoid cavity of healthy scapulae with millimeter accuracy. This technique has the potential to reconstruct the premorbid glenoid cavity shape, as it was prior to OA, and thus to guide the positioning of glenoid implants in total shoulder arthroplasty.

What is the best glenoid configuration in onlay reverse shoulder arthroplasty?

PURPOSE: The purpose of this study was to analyze the effect of different glenoid configurations on arm position and range of motion (ROM) following reverse shoulder arthroplasty (RSA). The hypothesis was that different glenoid configurations would lead to changes in humeral offset, acromio-humeral distance (AHD), ROM, and rotator cuff muscle length. METHODS: Using a three-dimensional (3D) computer model, implantation of an RSA was simulated with a 145° onlay humeral stem combined with five different glenoid configurations which varied in diameter and centre of rotation. Glenoid offset, the AHD, ROM, and muscle length were evaluated for each configuration. RESULTS: Changing glenoid design led to up to a 10 mm change in offset and a 3 mm change in the AHD. There was 7° of improvement in abduction and flexion between the different glenoid designs. Two of the configurations, the 36 mm centered and the BIO-RSA, had an adduction deficit. In extension and external rotation arm with the arm at side, the eccentric 36 mm glenosphere was the best configuration while the centered 36 mm glenosphere was the worst configuration. The 42 mm glenosphere limited external rotation at 90° of abduction. CONCLUSIONS: Varying the glenosphere configurations leads to ROM and muscle length changes following RSA. With a 145° onlay humeral stem, a 36 eccentric glenosphere theoretically optimizes ROM while limiting scapular notching.

Glenoid morphology and the safe zone for protecting the suprascapular nerve during baseplate fixation in reverse shoulder arthroplasty.

PURPOSE: The purpose of this study was to investigate glenoid morphology and define the safe zone for protecting the suprascapular nerve baseplate screw during baseplate fixation in reverse shoulder arthroplasty (RSA) in a Chinese population. METHODS: Shoulder computed tomography (CT) scans from 56 subjects were retrospectively reviewed. Three-dimensional (3D) reconstruction was performed using Mimics software, and corresponding bony references were used to evaluate glenoid morphology. To standardize evaluation, the coronal scapular plane was defined. Safe fixation distances and screw placements were investigated by constructing a simulated cutting plane of the baseplate during RSA. RESULTS: Mean glenoid height was 35.83 ± 2.95 mm, and width was 27.32 ± 2.78 mm, with significant sexual dimorphism (p < 0.01). According to the cutting plane morphology, the average baseplate radius was 13.84 ± 1.34 mm. The distances from the suprascapular notch and from two bony reference points at the base of the scapular spine to the cutting plane were 30.27 ± 2.77 mm, 18.39 ± 1.67 mm and 16.52 ± 1.52 mm, respectively, with a gender-related difference. Based on the clock face indication system, the danger zone caused by the suprascapular nerve projection was oriented between the two o'clock and eight o'clock positions in reference to the right shoulder. CONCLUSIONS: Glenoid size and the safe zone for screw fixation during RSA were characterized in a Chinese population. Careful consideration of baseplate fixation and avoidance of suprascapular nerve injury are important for improved clinical outcome.

Quantification of regional variations in glenoid trabecular bone architecture and mineralization using clinical computed tomography images.

The purpose of this study was to demonstrate feasibility of a clinical CT imaging and analysis technique to quantify regional variations in trabecular bone architecture and mineralization of glenoid bones. Specifically, our objective was to determine to what extent clinical CT imaging of intact upper extremities can describe variations of trabecular bone architectures at anatomic and peri-implant regions by comparing trabecular bone architectures as measured by high-resolution, micro CT imaging of same excised glenoid bones. Bone volume fraction (BVF), trabecular bone thickness (TbTh), number of trabecular bone (TbN), spacing (TbS), pattern factor (TbPf), bone surface area (BSA), and skeletal connectivity (Conn.), in addition to bone mineral content (BMC) and bone mineral density (BMD), were quantified from both clinical and micro CT images using whole bone, anatomic, and peri-implant bone masks. Strong correlations of BVF, TbTh, TbSp, BMC, and BMD were found between clinical CT and micro CT imaging methods. The variations in BVF, TbTh, TbSp, TbN, BMC, and BMD at anatomical and peri-implant regions were larger than those at whole bone regions. In this study, we have demonstrated that this clinical CT imaging methodology can be used to quantify variations of a patient's glenoid bone at anatomic and peri-implant levels. Statement of Clinical Significance. An in vivo quantitative assessment of glenoid trabecular bone architecture in the anatomic and peri-implant regions may improve our understanding on the role of bone quality on glenoid component loosening following total shoulder arthroplasty. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:85-96, 2018.

Bone grafts used for arthroscopic glenoid reconstruction restore the native glenoid anatomy.

PURPOSE: Recurrent anterior instability of the glenohumeral joint is a demanding condition, especially in cases of glenoid bone loss. Various treatment options have been described, such as arthroscopic grafting techniques and the Latarjet procedure. In this study, the degree to which an arthroscopically applied iliac crest graft restores the glenoid anatomy was evalutated. METHODS: Nine patients (three women and six men) with an average age of 31 ± 9 years (21-46 years) who were treated with an arthroscopic iliac crest graft technique were included in this study. After a mean follow up of 34 ± 10 months (19-50 months) after the procedure, MRI scans of both shoulders were performed and the glenoid width, Glenoid Index (GI), Pixel Signal intensity (PSI), thickness of the tissue covering the articular aspect of the graft, inclination, version, concavity and balance stability angle were measured. RESULTS: All scans showed the cultivation of tissue on the graft, which visually resembled the cartilage of the native ipsilateral glenoid. Additionally, reshaping of the graft to repair the glenoid configuration could be observed. Glenoid width (p = 0.022) and GI (p < 0.001) increased significantly through surgery. The tissue examined on the graft showed a significant pixel intensity gap (p = 0.017) but comparable thickness (n.s.) in relation to native cartilage. The remaining parameters did not differ significantly between both shoulders. CONCLUSION: In the cohort presented, iliac crest grafts were able to restore the glenoid configuration, and the glenoid was re-shaped to its native contour. Additionally, cartilage-like scar tissue with similar thickness as healthy cartilage was formed on the articular side of the graft. These results suggest that glenoid reconstruction is not only important for prevention of recurrence, but also for restoration of the native glenoid anatomy. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Glenoid exposure in total shoulder arthroplasty.

Glenoid exposure is agreed to be a difficult step, but is also a key step in total shoulder arthroplasty, both anatomic and reverse. It conditions unhindered use of the ancillary instrumentation and thus correct glenoid component positioning. The main stages comprise arthrotomy, by opening the rotator cuff, humeral head cut, and inferior glenohumeral release, enabling shifting of the humerus and good exposure of the glenoid cavity. The two main approaches are deltopectoral and anterosuperior transdeltoid. Using the deltopectoral approach, arthrotomy is performed through the subscapularis muscle, by various techniques. This approach enables extensive inferior glenohumeral release and thus an approach to the inferior apex of the glenoid cavity, which is a key area for glenoid implant positioning. The main drawbacks are postoperative shoulder instability and limited access to the posterior part of the glenoid in case of significant retroversion. Moreover, subscapularis healing is uncertain, which can impair the clinical outcomes, with risk of glenoid component loosening. Advantages, on the other hand, include the fact that it can be implemented in all cases, even the most difficult ones, and that the deltoid muscle is respected. The transdeltoid approach has the advantage of being simple, providing direct exposure of the glenoid cavity through a rotator cuff tear after passing through the deltoid. It is therefore especially indicated for reverse prosthesis in case of rotator cuff tear, and in traumatology. However, the approach to the inferior part of the glenoid cavity can be restricted, with insufficient exposure and a risk of glenoid component malpositioning (superior tilt). The preoperative assessment is essential, to detect at-risk situations such as severe stiffness and anticipate difficulties in glenoid exposure.

Does the position of the scapula in relation to the glenopolar angle change the preferred treatment of extra-articular fractures?

OBJECTIVE: To analyse the glenopolar angle (GPA) at different inclinations of the scapula using 3D CT, to test the hypothesis that the result could change the indication from conservative treatment to surgery. MATERIALS AND METHODS: Analysis of 30 3D CT images of patients' scapulae, measuring the GPA. The GPA was measured with scapulae at 0° and at 20° and 30° of internal and external rotation. Angles were compared by age, sex and examiner for the different angles of rotation of the scapulae. RESULTS: The GPA of scapulae in rotation tended to be smaller than the GPA without rotation, and the larger the degree of rotation, the more the angle was underestimated. Additionally, for the same degree of rotation, internal rotation was associated with greater underestimation of the GPA than external rotation. Two different examiners achieved an excellent level of agreement between angle measurements. The GPA with the scapula at 0° was significantly higher among elderly patients. The variation in GPA with the scapula in rotation (20° and 30°) in relation to the GPA without rotation was significantly greater for female patients. CONCLUSIONS: As the rotation of the scapula was displaced from the scapula in the coronal position (GPA 0°), both in internal rotation and in external rotation, the GPA reduced. Therefore, rotational displacement may lead to an error in GPA measurement, resulting in incorrect indication of treatment. It is recommended that whenever possible, GPA measurements should be taken in neutral rotation, with the scapula in a neutral position at 0°.