OBJECTIVE: The primary objective was to determine the population prevalence of glenohumeral joint imaging abnormalities in asymptomatic adults.
METHODS: We systematically reviewed studies reporting the prevalence of X-ray, ultrasound (US), computed tomography, and magnetic resonance imaging (MRI) abnormalities in adults without shoulder symptoms (PROSPERO registration number CRD42018090041). This report presents the glenohumeral joint imaging findings. We searched Ovid MEDLINE, Embase, CINAHL and Web of Science from inception to June 2023 and assessed risk of bias using a tool designed for prevalence studies. The primary analysis was planned for the general population. The certainty of evidence was assessed using a modified Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) for prognostic studies.
RESULTS: Thirty-five studies (4 X-ray, 10 US, 20 MRI, 1 X-ray and MRI) reported useable prevalence data. Two studies were population-based (846 shoulders), 15 studies included miscellaneous study populations (1715 shoulders) and 18 included athletes (727 shoulders). All were judged to be at high risk of bias. Clinical diversity precluded pooling. Population prevalence of glenohumeral osteoarthritis ranged from 15% to 75% (2 studies, 846 shoulders, 1 X-ray, 1 X-ray and MRI; low certainty evidence). Prevalence of labral abnormalities, humeral head cysts and long head of biceps tendon abnormalities were 20%, 5%, 30% respectively (1 study, 20 shoulders, X-ray and MRI; very low certainty evidence).
CONCLUSIONS: The population-based prevalence of glenohumeral joint imaging abnormalities in asymptomatic individuals remains uncertain, but may range between 30% and 75%. Better estimates are needed to inform best evidence-based management of people with shoulder pain.

Rehabilitation programs advocate early passive and assisted motion after rotator cuff repair to induce healing und maintaining range of motion while avoiding excessive strain on the repaired tendons. In-vivo glenohumeral joint contact forces reflect the compressive forces generated by the rotator muscles. In the present study, maximum in-vivo joint contact forces (FresMax) were determined to compare active and assisted execution of a single movement and the long-term development of joint compression forces. FresMax were measured in six patients who received instrumented, telemetric modified anatomical hemi endoprostheses of the shoulder joint between 2006 and 2008. Data were gathered 23 months postoperatively (2006-2010), were analysed and compared with measurements 133 months postoperatively. Additional imaging was obtained as x-rays and ultrasound examination. Data analysis was conducted by synchronizing video tapes and measured force curves. New imaging showed a rupture of the M. supraspinatus and progressive joint degeneration. FresMax nearly doubled during active compared to assisted execution of each of the four chosen movements. Over the course of 133 months post-surgery, the studied movements showed a decrease of active compression force, probably due to a ruptured supraspinatus, resulting in a lower active/assisted ratio. A long term follow up after eleven years, eight out of ten measured movements showed a decrease of FresMax. These results support current rehabilitation protocols recommending early passive and assisted motion to limit activation of the rotator muscles generating compressive forces. Following degeneration of the rotator cuff, active joint contact forces decrease over time.Level of evidence: III.

BACKGROUND: Glenohumeral posterior external rotation contractures and scapular winging are frequently overlooked problems in residual neonatal brachial plexus injury (NBPI). Recent attention has emphasized their impact on vital functions such as feeding and hygiene. This study aims to present the epidemiology of posterior glenohumeral (GH) contractures in a significant pediatric NBPI population and explore contributing factors.
METHODS: We conducted a retrospective analysis of data collected from January 2019 to November 2022, involving a case series of 262 children with residual NBPI. The data included demographics, palsy level, prior surgical history, and the modified Mallet scale. Glenohumeral passive internal rotation in abduction (IRABD) and cross-body adduction (CBADD) angles were measured bilaterally. Subjects were categorized into \'Belly-\' (Mallet Hand-to-Belly <3) and \'Belly+\' (Mallet Hand-to-Belly ≥3) groups.
RESULTS: Median participant age was 7.9 years (range: 3.5 - 21 years). Extension injury patterns included Erb\'s palsy (56.5%), extended Erb\'s palsy (28.6%), and global palsy (14.9%). Contractures exceeding 10, 20, and 30 degrees were prevalent in both IRABD and CBADD angles. The \'Belly-\' group (9.5%) demonstrated a significant reduction in both angles compared to the \'Belly+\' group. Weak correlations were found between IRABD (r=0.390, p<0.0001) or CBADD (r=0.163, p=0.0083) angles and Mallet hand-to-abdomen item. Glenohumeral reduction and Hoffer procedures led to a notable decrease in CBADD angle, without affecting \'Belly-\' prevalence. Global injuries exhibited decreased angles compared to Erb\'s group.
CONCLUSIONS: External rotation glenohumeral contractures are prevalent in residual NBPI, impacting midline access. Surprisingly, history of glenohumeral procedures or extensive injuries did not increase the likelihood of losing the ability to reach the belly. ROC analysis suggests specific thresholds for maintaining this ability.

Introduction: Osteoarthritis (OA) and rotator cuff tear (RCT) pathologies have distinct scapular morphologies that impact disease progression. Previous studies examined the correlation between scapular morphology and glenohumeral joint biomechanics through critical shoulder angle (CSA) variations. In abduction, higher CSAs, common in RCT patients, increase vertical shear force and rotator cuff activation, while lower CSAs, common in OA patients, are associated with higher compressive force. However, the impact of the complete patient-specific scapular morphology remains unexplored due to challenges in establishing personalized models. Methods: CT data of 48 OA patients and 55 RCT patients were collected. An automated pipeline customized the AnyBody™ model with patient-specific scapular morphology and glenohumeral joint geometry. Biomechanical simulations calculated glenohumeral joint forces and instability ratios (shear-to-compressive forces). Moment arms and torques of rotator cuff and deltoid muscles were analyzed for each patient-specific geometry. Results and discussion: This study confirms the increased instability ratio on the glenohumeral joint in RCT patients during abduction (mean maximum is 32.80% higher than that in OA), while OA patients exhibit a higher vertical instability ratio in flexion (mean maximum is 24.53% higher than that in RCT) due to the increased inferior vertical shear force. This study further shows lower total joint force in OA patients than that in RCT patients (mean maximum total force for the RCT group is 11.86% greater than that for the OA group), attributed to mechanically advantageous muscle moment arms. The findings highlight the significant impact of the glenohumeral joint center positioning on muscle moment arms and the total force generated. We propose that the RCT pathomechanism is related to force magnitude, while the OA pathomechanism is associated with the shear-to-compressive loading ratio. Overall, this research contributes to the understanding of the impact of the complete 3D scapular morphology of the individual on shoulder biomechanics.

UNASSIGNED: The relationship between lower mobility, as measured by the elbow forward translation motion (T-motion) test, a new indicator of shoulder joint complex movement that measures elbow position when both dorsal hands are placed on the iliac crest while in a sitting position, and the parameters calculated by ultrasonography is unknown. The purpose of this study was to investigate the limiting factors of T-motion through motion analysis of the humeral head and rotator cuff muscles using ultrasonography in college baseball players.
UNASSIGNED: Thirteen college baseball players participated in this cross-sectional study. The shortest distance from the posterior edge of the glenoid to the humeral head was measured in the static and T-motion positions, and the difference was calculated as the humeral head translation. The velocity of the infraspinatus was calculated during shoulder internal/external rotation using the particle image velocimetry method. These parameters were compared between the throwing and nonthrowing sides to examine the limiting factors of T-motion.
UNASSIGNED: This study indicated moderate-to-good reliability for the parameters calculated by ultrasonography. The mean anterior translation distance was significantly greater on the throwing side than on the nonthrowing side (r = 0.56, P = .015). The mean velocity of infraspinatus during internal rotation was significantly lower on the throwing side than on the nonthrowing side (r = 0.51, P = .028).
UNASSIGNED: Increased anterior translation of the humeral head and decreased the velocity of infraspinatus are likely correlated with reduced T-motion mobility in college baseball players. These methods showed potential for physical therapy assessment and intervention to prevent shoulder dysfunction.

(1) Background: Osteoarthritis is a degenerative joint disease that is commonly diagnosed in the aging population. Interestingly, the lower extremity joints have a higher published incidence of osteoarthritis than the upper extremity joints. Although much is known about the disease process, it remains unclear why some joints are more affected than others. (2) Methods: A comprehensive literature review was conducted utilizing the search engines PubMed, Google Scholar, and Elsevier from 2014 to 2024, directing our search to osteoarthritis of various joints, with the focus being on glenohumeral osteoarthritis. (3) Results and Discussion: The literature review revealed a publication difference, which may be explained by the inconsistency in classification systems utilized in the diagnosis of shoulder osteoarthritis. For instance, there are six classification systems employed in the diagnosis of glenohumeral osteoarthritis, making the true incidence and, therefore, the prevalence unobtainable. Furthermore, susceptibility to osteoarthritis in various joints is complicated by factors such as joint anatomy, weight-bearing status, and prior injuries to the joint. (4) Conclusions: This review reveals the lack of understanding of shoulder osteoarthritis\'s true incidence and prevalence while considering the anatomy and biomechanics of the glenohumeral joint. In addition, this is the first paper to suggest a single criterion for the diagnosis of glenohumeral osteoarthritis.

The aim of this review is to evaluate existing isokinetic testing protocols for the shoulder in tactical occupations, document their shoulder strength profiles, and determine any associations to shoulder injury. Four electronic databases were searched (Medline/Pubmed, Ovid/Emcare, CINAHL/Ebsco and Embase) using the keywords police OR law enforcement, firefighter, military, AND isokinetic. Articles were eligible if they had at least one cohort of a tactical population and included isokinetic testing of the glenohumeral joint. The search yielded 275 articles. After screening for duplicates and inclusion criteria, 19 articles remained for review, six of which assessed injury correlation. 17 articles evaluated military personnel and two examined firefighters. Articles were categorized by study design, population, isokinetic protocols, strength outcome measures and statistical measures. Concentric internal rotation (IR) and external rotation (ER) strength at 60 degrees/second were reported most frequently (84% of cases). There was a paucity of testing speeds, repetition ranges and contraction types evaluated when compared to existing literature in other populations with high shoulder injury occurrence such as overhead and collision athletes. Outside of military cohorts, there is limited data available to characterise the isokinetic strength profile of the shoulder in tactical occupations. Meta-analysis for injury association was unable to be performed due to independent variable and statistical heterogeneity. However, a best evidence synthesis suggested conflicting evidence to support the association of injury with isokinetic strength testing in tactical populations. Future studies should prioritise prospective designs utilising variable speeds, repetition schemes and contraction types to better capture the dynamic occupational demands in tactical groups.

OBJECTIVE: Image-guided ultrasound or fluoroscopic glenohumeral injections have high accuracy rates but require training, equipment, cost, and radiation exposure (fluoroscopy). In contrast, landmark-guided glenohumeral injections do not require additional subspecialist referrals or equipment. An optimal technique would be safe and accurate and have few barriers to implementation. The purpose of this study was to define the accuracy of glenohumeral needle placement via an anterior landmark-guided approach as assessed by direct arthroscopic visualization.
METHODS: A consecutive series of adult patients undergoing shoulder arthroscopy in the beach chair position were included in this study. Demographic and procedural data were collected. The time required to perform the injection, the precise location of the needle tip, and factors that affected the accuracy of the injection were also assessed.
RESULTS: A standardized anterior landmark-guided glenohumeral joint injection was performed in the operating room prior to surgery, and the location of the needle tip was documented by arthroscopic visualization with a low complication profile and few barriers to implementation. A total of 81 patients were enrolled. Successful intra-articular glenohumeral needle placement by sports medicine and shoulder/elbow fellowship-trained orthopedic surgeons was confirmed in 93.8% (76/81) of patients. The average time to complete the procedure was 24.8 ​s. There were no patient-related variables associated with nonintra-articular injections in the cohort.
CONCLUSIONS: This study demonstrated that the technique of anterior landmark-guided glenohumeral injection has an accuracy of 93.8% and requires less than 30 ​s to perform. This method is safe, yields similar accuracy to image-guided procedures, has improved cost and time efficiency, and requires less radiation exposure. No patient-related factors were associated with inaccurate needle placement. Anterior landmark-guided glenohumeral injections may be utilized with confidence by providers in the clinical setting.
METHODS: Level 5. IRB: Approved under Stanford IRB-56323.

OBJECTIVE: We aimed to develop a consensus-based rehabilitation guideline specifically designed to reduce apprehension following arthroscopic Bankart repair after traumatic anterior shoulder dislocation. DESIGN: Delphi-based consensus. METHOD: A comprehensive list of interventions for potential inclusion in a postoperative rehabilitation guideline was developed. American and European physiotherapists and orthopedic surgeons were invited to participate in a Delphi panel, engaging in 3 survey rounds. The health professionals were surveyed about their level of agreement on both initially listed and newly suggested interventions. Consensus was established when a \"critical-to-include\" rating was given in ≥70% of all responses. Ten former patients were consulted to identify the intervention during standard care rehabilitation that had the most impact on reducing postoperative apprehension following ABR. Any interventions not initially listed in the first round were added to the second survey round of the Delphi process. RESULTS: Forty-four health professionals reached consensus on a set of 27 interventions for managing apprehension after arthroscopic Bankart repair. New interventions included gradual exposure to shoulder positions eliciting apprehension, training in anterior stability-provoking positions, and education addressing the impact of psychosocial factors. Former patients identified specific interventions that were effective in reducing postoperative apprehension following ABR. These interventions encompassed medicine ball throws, active-assisted wall slides, and kinetic chain exercises in anterior stability-provoking positions. CONCLUSION: Our Delphi process informed expert recommendations for various interventions aimed at addressing apprehension associated with ABR. The recommendations were the foundation for developing a rehabilitation guideline (REGUIDE). The REGUIDE integrates principles from cognitive-behavioral therapy to improve rehabilitation and mitigate apprehension. J Orthop Sports Phys Ther 2024;54(5):1-13. Epub 20 March 2024. doi:10.2519/jospt.2024.12106.

BACKGROUND: The aim of the work was to investigate the influence of the position of a fractured greater tubercle of the humerus on stress distribution in the glenohumeral joint (GHJ) at shoulder abduction by performing stress-strain analysis (SSA).
METHODS: A simulated 3D model of the shoulder was constructed on the basis of anatomical and anthropometric data as close as possible to real ones using the SolidWorks software package.
RESULTS: A finite-element model (FEM) was generated in a semi-automatic mode composed mostly of tetrahedral and hexagonal elements < 1 mm in dimensions.
CONCLUSIONS: The simulated 3D model of the shoulder, based on anatomical and anthropometric data as close as possible to the real ones, makes possible highly accurate determination of the optimal mutual position of the movable elements of the real joint individually for each specific patient, and makes it possible to accurately perform a minimally invasive surgical operation.