Glenohumeral Motion Research Articles

Rotator Cuff Repair by All-Arthroscopic Versus Mini-Open Technique: A Comparison of Clinical and Functional Outcome.

Rotator cuff tears can lead to debilitating shoulder function and impairment. Rotator cuff repair aims to eliminate pain and improve function with increased shoulder strength and range of motion. This study evaluated the differences between all-arthroscopic (AA) and mini-open (MO) repair procedures for rotator cuff tendon tears regarding clinical and functional outcomes. This was a prospective study conducted at a tertiary care government Hospital in Kolkata, India, between March 2015 and September 2016 which evaluated 25 patients who had undergone all-arthroscopic surgery and 25 patients who underwent mini-open repair (total of 50 patients) for rotator cuff tear with a minimum one-year follow-up. The UCLA score was used to assess the functional outcome of these patients. The mean age of all patients included in this study was 45.32 years. 86% of patients were male. The two groups had similar demographic characteristics, pre-operative baseline parameters, and intra-op findings. The average UCLA score showed significant improvement from 13.92 pre-operatively to 29.76 at the final follow-up. The patients in the all-arthroscopic surgery group experienced a notable decrease in pain within the first three months compared to the mini-open group. However, at the time of the final follow-up, no significant difference was noted between both groups when comparing the University of California at Los Angeles (UCLA) score, Visual Analogue Scale (VAS) score for pain, and active or passive glenohumeral motion. The outcomes of all-arthroscopic and mini-open rotator cuff repair surgery are equivocal in terms of both clinical and functional results, with no significant difference in post-operative pain, shoulder joint strength range of motion, or patient satisfaction over the long term.

Impact of tendon transfer on scapulothoracic and glenohumeral motion in children with brachial plexus birth injuries

BackgroundTendon transfers are often utilized to improve shoulder external rotation and abduction in children with brachial plexus birth injuries and are designed to improve glenohumeral (GH) joint motion. However, changes in scapulothoracic (ST) and glenohumeral (GH) joint function after tendon transfer are not well defined. The purpose of this study was to quantify changes in GH, ST, and humerothoracic (HT) joint function before and after tendon transfer, and we hypothesized that tendon transfers would reorient the arc of motion into more external rotation and abduction, but not increase GH motion. MethodsMotion analysis was performed in 15 children (ages 3-16) before and after transfer of teres major and/or latissimus dorsi. Scapulothoracic, GH, and HT joint angles were measured in a neutral, resting position and each of the modified Mallet positions. Joint angular displacements from the neutral position and the total arc of internal-external rotation for each joint were also calculated. Relevant joint angles, joint angular displacements, and internal-external rotation arcs were compared using multivariate analyses of variance with repeated measures and univariate post-hoc analyses. ResultsGlenohumeral and HT external rotation were significantly increased in all positions postoperatively. The arc of GH internal-external rotation was unchanged, but oriented in more external rotation after surgery. Only 6 patients gained active external rotation. Glenohumeral and HT internal rotation were significantly decreased after surgery, but ST internal rotation was significantly increased. Two patients had loss of midline function. In the abduction position, GH elevation joint angles were unchanged, but ST and HT elevation increased. DiscussionOnly four patients gained active GH external rotation and maintained their internal rotation. Each of those patients underwent isolated tendon transfer without concomitant joint release. Seven patients maintained their preoperative internal rotation, which was attributed to increased ST internal rotation. The other half of patients lost internal rotation and gained external rotation through reorientation of the arc of rotation. Nine patients gained HT elevation, with three attributed to increased ST upward rotation, five attributed to a combination of increased ST upward rotation and increased GH elevation, and one attributed to increased GH abduction contracture. These findings challenge the dogma that teres major/latissimus dorsi tendon transfers augment GH motion and highlight the importance of ST function for outcome determination.

Challenges and Outcomes in the Management of Periprosthetic Humeral Fractures: A Retrospective Study and Review of Current Approaches.

Periprosthetic humeral fractures are a rare and increasing entity due to the rising number of shoulder arthroplasties. These fractures pose a significant challenge for surgeons, with incidence rates ranging from 1.2% to 19.4%. They can occur intraoperatively or as late complications, often influenced by trauma, prosthetic wear, or loosening. A retrospective study was conducted on all patients admitted with periprosthetic humeral fractures over a four-year period (2018-2022). Inclusion criteria were postoperative periprosthetic humeral fractures with a minimum follow-up of six months. Exclusion criteria included intraoperative fractures, fractures of the glenoid or coracoid process, and cases with follow-up of less than six months or incomplete data. The study included six patients with an average age of 83.1 years, predominantly female (four females andtwo males). All fractures occurred postoperatively: four on reverse shoulder prostheses, one on an anatomical prosthesis, and one on a hemiarthroplasty. The mechanism was low-energy trauma, with fractures occurring an average of 96 months post-initial surgery. Fractures were classified using the Campbell system: three in region 4, two in region 3, and one in region 2. Radiographs showed four cemented and two uncemented stems. Three patients underwent surgical treatment with either prosthetic replacement using a long stem and fracture cerclage or lockingcompression plate (LCP). The remaining three patients were treated conservatively with a Sarmiento brace due to advanced age, bone fragility, low functional demand, and comorbidities. Radial nerve palsy was a complication in two patients post-trauma, with one recovering fully and the other not recovering before death due to associated complications. All fractures consolidated within an average of seven months (range: 5-8 months).Functional recovery was satisfactory with a median Constant-Murley Shoulder Score of 69in surgically treated patients, with range of motion between 100 and 140 degrees. Only two conservatively treated patients achieved fracture consolidation, and functional recovery was inadequate. Managing periprosthetic humeral fractures remains challenging. Treatment goals include fracture healing, maintaining prosthetic stem stability, preserving glenohumeral motion, and restoring shoulder function. Despite various classification systems, the literature shows limited and variable data on incidence and treatment outcomes. Conservative treatment may be considered for stable implants and acceptable alignment, but surgical intervention is often necessary for displaced fractures or implant loosening. The management of periprosthetic humeral fractures requires a tailored, multidisciplinary approach to optimize outcomes and improve patient quality of life. With the increasing incidence of these fractures due to the growing use of shoulder arthroplasty, ongoing research and development of new techniques and therapeutic strategies are essential to address this clinical challenge effectively.

Glenohumeral internal rotation deficit: insights into pathologic, clinical, diagnostic, and therapeutic characteristics.

Overhead athletes undergo significant biomechanical adaptations due to repetitive overhead movements, primarily affecting the glenohumeral joint. These adaptations can lead to glenohumeral internal rotation deficit (GIRD), which is characterized by posterior capsule stiffness that results in glenohumeral joint translation and a shift in the center of gravity. The severity of GIRD is dependent upon the presence of asymmetry between gained external and lost internal rotation, which is defined clinically as an asymmetry exceeding 20º; this reduces the total range of motion compared to the unaffected limb or baseline measurements. Diagnosis is challenging, as it can be mistaken for chronic scapular adaptations. To mitigate misdiagnosis, a high clinical suspicion is crucial in overhead athletes, especially those who began performing forceful overhead movements before closure of growth plates. Periodic physical examinations should establish baseline values for glenohumeral rotation and track changes in glenohumeral motion to aid in diagnosis. Symptoms of GIRD include shoulder pain, stiffness, and decreased force exertion. Magnetic resonance imaging is the preferred imaging method for evaluating GIRD and assessing concomitant soft tissue pathologies. Untreated GIRD can lead to rotator cuff strength imbalances. Treatment mainly involves conservative measures, such as physical therapy, to improve internal rotation and alleviate posterior tightness. Surgical interventions are considered when symptoms persist despite conservative treatment with physical therapy or in the presence of concomitant pathologies.

Pharmacoacupuncture for the Treatment of Frozen Shoulder: protocol for a systematic review and meta-analysis.

Frozen shoulder (FS) is one of the most challenging shoulder disorders for patients and clinicians. Its symptoms mainly include any combination of stiffness, nocturnal pain, and limitation of active and passive glenohumeral joint movement. Conventional treatment options for FS are physical therapy, nonsteroidal anti-inflammatory drugs, injection therapy, and arthroscopic capsular release, but adverse and limited effects continue to present problems. As a result, pharmacoacupuncture (PA) is getting attention as an alternative therapy for patients with FS. PA is a new form of acupuncture treatment in traditional Korean medicine (TKM) that is mainly used for musculoskeletal diseases. It has similarity and specificity compared to corticosteroid injection and hydrodilatation, making it a potential alternative injection therapy for FS. However, no systematic reviews investigating the utilization of PA for FS have been published. Therefore, this review aims to standardize the clinical use of PA for FS and validate its therapeutic effect. The protocol was registered in Prospero (CRD42023445708) on 18 July 2023. Until Aug. 31, 2023, seven electronic databases will be searched for randomized controlled trials of PA for FS. Authors will be contacted, and manual searches will also be performed. Two reviewers will independently screen and collect data from retrieved articles according to predefined criteria. The primary outcome will be pain intensity, and secondary outcomes will be effective rate, Constant-Murley Score, Shoulder Pain and Disability Index, range of motion, quality of life, and adverse events. Bias and quality of the included trials will be assessed using the Cochrane handbook's risk-of-bias tool for randomized trials. Meta analyses will be conducted using Review Manager V.5.3 software. GRADE will be used to evaluate the level of evidence for each outcome. This systematic review and meta-analysis will be conducted following PRISMA statement. The results will be published in a peer-reviewed journal. This review will provide scientific evidence to support health insurance policy as well as the standardization of PA in clinical practice.

Anterior Latissimus Dorsi Transfer for Irreparable Subscapularis Tears Improves Shoulder Kinematics in a Dynamic Biomechanical Cadaveric Shoulder Model

Background: In young patients with irreparable subscapularis deficiency (SSC-D) and absence of severe osteoarthritis, anterior latissimus dorsi transfer (aLDT) has been proposed as a treatment option to restore the anteroposterior muscular force couple to regain sufficient shoulder function. However, evidence regarding the biomechanical effect of an aLDT on glenohumeral kinematics remains sparse. Purpose/Hypothesis: The purpose of this study was to investigate the effects of an aLDT on range of glenohumeral abduction motion, superior migration of the humeral head (SM), and cumulative deltoid force (cDF) in a simulated SSC-D model using a dynamic shoulder model. It was hypothesized that an aLDT would restore native shoulder kinematics by reestablishing the insufficient anteroposterior force couple. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric shoulders were tested using a validated shoulder simulator. Glenohumeral abduction angle (gAA), SM, and cDF were compared across 3 conditions: (1) native, (2) SSC-D, and (3) aLDT. gAA and SM were measured using 3-dimensional motion tracking, while cDF was recorded in real time during dynamic abduction motion by load cells connected to actuators. Results: The SSC-D significantly decreased gAA (Δ–9.8°; 95% CI, –14.1° to −5.5°; P < .001) and showed a significant increase in SM (Δ2.0 mm; 95% CI, 0.9 to 3.1 mm; P = .003), while cDF was similar (Δ7.8 N; 95% CI, –9.2 to 24.7 N; P = .586) when compared with the native state. Performing an aLDT resulted in a significantly increased gAA (Δ3.8°; 95% CI, 1.8° to 5.7°; P < .001), while cDF (Δ–36.1 N; 95% CI, –48.7 to −23.7 N; P < .001) was significantly reduced compared with the SSC-D. For the aLDT, no anterior subluxation was observed. However, the aLDT was not able to restore native gAA (Δ–6.1°; 95% CI, –8.9° to −3.2°; P < .001). Conclusion: In this cadaveric study, performing an aLDT for an irreparable subscapularis insufficiency restored the anteroposterior force couple and prevented superior and anterior humeral head migration, thus improving glenohumeral kinematics. Furthermore, compensatory deltoid forces were reduced by performing an aLDT. Clinical Relevance: Given the favorable effect of the aLDT on shoulder kinematics in this dynamic shoulder model, performing an aLDT may be considered as a treatment option in patients with irreparable SSC-D.

Comparative Effectiveness of Proprioceptive Neuromuscular Facilitation Stretch Vs Spencer Muscle Energy Technique on Pain and Disability in Patients with Adhesive Capsulitis

Purpose: Adhesive capsulitis is a condition in which the tissues of the shoulder joint become tight and impede movement. It is characterized by gradual loss of both active and passive glenohumeral joint motion, resulting in fibrosis, scarring and contractures of the joint capsule. Patient with adhesive capsulitis usually have difficulty in performing overhead activities, as well as routine duties such as combing their hair, dressing themselves, and throwing a ball. The objective of this study was to determine the effectiveness of proprioceptive neuromuscular facilitation (PNF) stretch vs muscle energy technique (MET) on pain and disability in patients with adhesive capsulitis.&#x0D; Methodology: Study Design: This research employed a rigorous single-blinded randomized controlled trial design to investigate the comparative effectiveness of two manual therapy techniques in the management of adhesive capsulitis. The study was conducted in accordance with established ethical guidelines and principles. Participant Selection: A total of 30 participants, aged between 30 and 60 years, were recruited for this study. The selection process adhered to specific inclusion and exclusion criteria to ensure the homogeneity of the participant group. Inclusion criteria encompassed individuals in the 2nd and 3rd stages of adhesive capsulitis, both males and females, those with comorbid conditions such as diabetes and hypertension, and individuals experiencing painful restrictions in active and passive glenohumeral or periscapular motion. It was essential that participants had the ability to understand Punjabi or Urdu and were willing to participate. Exclusion criteria included individuals with a history of post-traumatic immobilization, cognitive impairment, previous surgery or arthroscopy, cervical pathology, neoplasm/tumor, or reflex sympathetic dystrophy. Informed Consent: Before the commencement of the study, informed consent was obtained from all participants. The participants were fully informed of the study's objectives, procedures, and potential risks and benefits. The rights of voluntary participation and the option to withdraw from the study at any time were emphasized. Participant data were anonymized and kept confidential throughout the research process to safeguard privacy. Randomization: To minimize bias, participants were randomly assigned to two distinct treatment groups, Group A and Group B. The randomization process was conducted using a computer-generated method, ensuring that each participant had an equal chance of being assigned to either group. Interventions: The study employed two distinct manual therapy techniques for the treatment of adhesive capsulitis. Group A received proprioceptive neuromuscular facilitation (PNF) stretching, while Group B underwent the Spencer muscle energy technique (MET). Both interventions were administered over a duration of one month. Baseline Treatment: In addition to the primary interventions, all participants received a hot pack as a baseline treatment. This standard treatment approach aimed to create a consistent baseline condition for all participants and to alleviate any discomfort. Data Collection: The collection of data was a crucial aspect of this study. Data were gathered through the utilization of structured data collection forms, designed to capture demographic information and adhere to the inclusion and exclusion criteria. Additionally, standardized assessment tools were used to quantify outcomes. The Shoulder Pain Assessment Disability Index (SPADI) was employed to evaluate both pain and functional disability, while the Numeric Rating Scale (NRS) was utilized to measure pain intensity.&#x0D; Findings: Statistical analysis was done by using statistical package for the social sciences (SPSS) version 28. The collected data was analyzed and presented using appropriate statistical techniques. The data were initially checked for normality using the Kolmogorov-Smirnov and Shapiro-Wilk tests. Non-parametric tests were employed due to the non-normal distribution of the data. Qualitative data were analyzed for frequency and percentage. Intra-group differences were examined using the Wilcoxon signed-rank t-test, while inter-group differences were assessed with the Mann Whitney U-test. Spencer mean Mets treatment group has lower mean ranks in total SPADI pain as compared to PNF study group.&#x0D; Conclusion: the study concluded that Spencer Mets has been more effective in reducing the pain of the patients as compared to PNF treatment. Healthcare professionals involved in the treatment of patients with adhesive capsulitis should consider the incorporation of Spencer MET as a viable option for pain management. The superior pain reduction observed in this study suggests that this technique may yield favorable results in real-world clinical settings. While this study offers valuable insights, further research is warranted to explore the long-term effects and potential differences in functional outcomes between Spencer MET and PNF treatment. Comparative studies with larger sample sizes and extended follow-up periods can provide a more comprehensive understanding of the benefits of these techniques.

The effect of medial shift of supraspinatus tendon on the glenohumeral joint motion-a cadaveric study.

Full-thickness retracted massive supraspinatus tears are a challenge for arthroscopic surgeons where multiple options for treatment exist, but medializing the attachment is a relatively easy procedure for which a decision can be taken intraoperatively. We investigate the viability of MATERIAL AND METHODS: Ten freshly thawed cadavers were taken and dissected. The supraspinatus tendon was resected, and then its attachment was progressively medialized. The range of motion (abduction, internal and external rotation) was recorded and compared. As a result, we noted a statistically significant decrease inabduction, internal and external rotationwith progressive medialization of the supraspinatus insertion. Medialized repair of the supraspinatus can be performed only to an extent beyond which it compromises glenohumeral motion. We noted a statistically significant decrease in ROM with even a 3 mm medialization of the tendon, but the acceptable medialization has to be determined on a case-to-case basis.

Reliability and Concurrent Validity of a Markerless, Single Camera, Portable 3D Motion Capture System for Assessment of Glenohumeral Mobility.

Recent technological advancements have enabled medical, sport, and fitness professionals to utilize digital tools that assist with conducting movement examinations and screenings. One such advancement has been the implementation of a single camera, markerless, and portable 3D motion capture system designed to obtain ROM measurements for multiple body parts simultaneously. However, the reliability and validity of a markerless 3D motion capture system that uses a single camera has not been established. The purpose of this study was to investigate the reliability and concurrent validity of this 3D motion capture system compared to a goniometer in assessing ROM of the glenohumeral joint. Quasi-experimental reliability, convenience sampling. Forty healthy volunteers (mean ± SD, age 27.4 ± 12.4 years, height 173.4 ± 11.1 cm, weight 72.1 ± 16.2 kg) participated in this study. Intrarater reliability was analyzed by ICC(2,k) with a 95% CI using two repeated trials for each shoulder movement (flexion, abduction, external rotation, internal rotation) that were recorded simultaneously via two methods: a standard goniometer and a 3D motion capture system. Concurrent validity was analyzed using Pearson Correlation Coefficient (r). The intrarater reliability between the two instruments for glenohumeral motions yielded an overall ICC of 0.82 (95% CI: 0.74-0.88) indicating good reliability for both instruments.The 3D motion capture system demonstrated strong correlations with goniometry for shoulder flexion (r = 0.67), abduction (r = 0.63), and external rotation (r = 0.76), and very strong correlation for shoulder internal rotation (r = 0.84). Results from this study indicated that a markerless, single camera, portable 3D motion capture system can be a reliable and valid tool to assess glenohumeral joint ROM in comparison to a standard goniometer. 3.

Musculoskeletal model-based control strategy of an over-actuated glenohumeral simulator to assess joint biomechanics

Abstract Determining the acting shoulder and muscle forces in vivo is very complex. In this study, we developed a control strategy for a glenohumeral simulator for ex vivo experiments that can mimic physiological glenohumeral motion and overcome the problem of over-actuation. The system includes ten muscle portions actuated via cables to induce upper arm motion in three degrees of freedom, including scapula rotation. A real-time optimizer was implemented to handle the over-actuation of the glenohumeral joint while ensuring a minimum of muscle tension. The functionality of the real-time optimizer was also used to simulate different extents of rotator cuff tears. Joint reaction forces were consistent with in vivo measurements. These results demonstrate the feasibility and added value of implementing a real-time optimizer for using in vivo data to drive a shoulder simulator.

Development of a Cadaveric Shoulder Motion Simulator with Open-Loop Iterative Learning for Dynamic, Multiplanar Motion: A Preliminary Study.

Ex vivo shoulder motion simulators are commonly used to study shoulder biomechanics but are often limited to performing simple planar motions at quasi-static speeds using control architectures that do not allow muscles to be deactivated. The purpose of this study was to develop an open-loop tendon excursion controller with iterative learning and independent muscle control to simulate complex multiplanar motion at functional speeds and allow for muscle deactivation. The simulator performed abduction/adduction, faceted circumduction, and abduction/adduction (subscapularis deactivation) using a cadaveric shoulder with an implanted reverse total shoulder prosthesis. Kinematic tracking accuracy and repeatability were assessed using maximum absolute error (MAE), root mean square error (RMSE), and average standard deviation (ASD). During abduction/adduction and faceted circumduction, the RMSE did not exceed 0.3, 0.7, and 0.8 degrees for elevation, plane of elevation, and axial rotation, respectively. During abduction/adduction, the ASD did not exceed 0.2 degrees. Abduction/adduction (subscapularis deactivation) resulted in a loss of internal rotation, which could not be restored at low elevation angles. This study presents a novel control architecture, which can accurately simulate complex glenohumeral motion. This simulator will be used as a testing platform to examine the effect of shoulder pathology, treatment, and rehabilitation on joint biomechanics during functional shoulder movements.

Paper 17: Decreased Glenohumeral External Rotation is associated with Elbow Injury in Adolescent Baseball Pitchers

Objectives: To compare bilateral standard glenohumeral range of motion, humeral torsion &amp; humeral torsion-corrected glenohumeral range of motion within and between healthy adolescent baseball pitchers &amp; adolescent baseball pitchers who have an injury to the throwing elbow. Secondarily, to analyze the relationship between humeral torsion angle and glenohumeral rotational motion in adolescent pitchers. Methods: Baseball pitchers aged 13-17 were prospectively enrolled into either a healthy group, if currently pitching in the community without complaint or injured group, if they presented to clinic for an elbow injury related to pitching. Bilateral standard glenohumeral internal &amp; external rotation was measured in degrees using a bubble goniometer with the scapulothoracic joint manually stabilized. Bilateral humeral torsion angles were measured using an Ultrasound &amp; bubble goniometer and were used to calculate humeral torsion-corrected glenohumeral range of motion. Parametric tests were used to compare values within and between groups for both the dominant and non-dominant extremities with significance defined as p&lt;0.05. Pearson’s correlation was used to evaluate the relationship between humeral torsion and standard glenohumeral motion in each group. Results: Twenty-nine healthy and twenty-five injured pitchers were enrolled with no difference in age or hand dominance between groups. The dominant shoulder of both the healthy (Table 2) and injured (Table 3) groups demonstrated a significant increase in humeral retrotorsion with increased standard glenohumeral external rotation &amp; GIRD. However, no difference in humeral torsion-corrected range of motion was present within groups. Injured pitchers displayed less standard &amp; humeral torsion-corrected external rotation of the dominant shoulder as well as less standard external rotation of the non-dominant shoulder compared to the healthy pitchers (Table 4). No difference in internal rotation measurements or humeral torsion was found between groups. A moderate correlation was found between ipsilateral humeral torsion angle and standard glenohumeral external (r=0.49) &amp; internal rotation (r=-0.58) in the dominant shoulder of healthy pitchers (Figure 1) but no correlation (r&lt; 0.3) was found between these measures in the dominant shoulder of injured pitchers. Conclusions: Both healthy &amp; injured adolescent baseball pitchers displayed dominant shoulder GIRD, external rotation gain &amp; retrotorsion of the humerus. In healthy pitchers, dominant glenohumeral motion was correlated to the humeral torsion angle suggesting that the osseous adaptation of humerus significantly contributed to these findings. However, this correlation was not found in the injured pitchers, suggesting that soft tissue factors played a larger role in the development of GIRD &amp; external rotation gain in this group. Additionally, injured pitchers displayed less standard glenohumeral external rotation of both shoulders and less humeral torsion-corrected external rotation of the dominant shoulder compared to healthy pitchers. This suggests a baseline difference in the soft tissue and/or structure of the pitchers’ shoulders between groups. Glenohumeral internal rotation and humeral retrotorsion were not associated with injury status in our study. Clinically, this study suggests that rehabilitation programs including modalities to improve external rotation may be of benefit for adolescent baseball pitchers with elbow injuries &amp; further research on the structural variations of the adolescent pitching shoulder is needed. [Table: see text][Table: see text][Table: see text]

Non-operative management of shoulder osteoarthritis: Current concepts

Glenohumeral osteoarthritis (OA) is one of the most common causes of shoulder pain. Conservative treatment options include physical therapy, pharmacological therapy, and biological therapy. Patients with glenohumeral OA present shoulder pain and decreased shoulder range of motion (ROM). Abnormal scapular motion is also seen in patients as adaptation to the restricted glenohumeral motion. Physical therapy is performed to (1) decrease pain, (2) increase shoulder ROM, and (3) protect the glenohumeral joint. To decrease pain, it should be assessed whether the pain appears at rest or during shoulder motion. Physical therapy may be effective for motion pain rather than rest pain. To increase shoulder ROM, the soft tissues responsible for the ROM loss need to be identified and targeted for intervention. To protect the glenohumeral joint, rotator cuff strengthening exercises are recommended. Administration of pharmacological agents is the major part next to physical therapy in the conservative treatment. The main aim of pharmacological treatment is the reduction of pain and diminution of inflammation in the joint. To achieve this aim, non-steroidal anti-inflammatory drugs are recommended as first-line therapy. Additionally, the supplementation of oral vitamin C and vitamin D can help to slow down cartilage degeneration. Depending on the individual comorbidities and contraindications, sufficient medication with good pain reduction is thus possible for each patient. This interrupts the chronic inflammatory state in the joint and, in turn, enables pain-free physical therapy. Biologics such as platelet-rich plasma, bone marrow aspirate concentrate, and mesenchymal stem cells have gathered increased attention. Good clinical outcomes have been reported, but we need to be aware that these options are helpful in decreasing shoulder pain but neither stopping the progression nor improving OA. Further evidence of biologics needs to be obtained to determine their effectiveness. In athletes, a combined approach of activity modification and physical therapy can be effective. Oral medications can provide patients with transient pain relief. Intra-articular corticosteroid injection, which provides longer-term effects, must be used cautiously in athletes. There is mixed evidence for the efficacy of hyaluronic acid injections. There is still limited evidence regarding the use of biologics.

Scapulohumeral rhythm in shoulders with reverse shoulder arthroplasty measured with a new portable three-dimensional scapular kinematics assessment system.

Reverse shoulder arthroplasty (RSA) is a valid and increasingly popular treatment option in eccentric arthrosis and cuff arthropathy. We know that the deltoid is the motor of RSA. However, the role of scapular motion has been poorly documented in the literature. The aim of our study is to analyze and quantify the role of the scapular contribution in the functional outcome of patients undergoing RSA. Fourteen patients who underwent primary RSA were included in the study. In all cases, a reverse prosthesis with lateralizing stem was implanted. All patients underwent clinical examination, video recording, and motion analysis. X-ray and postoperative CT examinations were collected to evaluate positioning and any loosening. ShowMotion (NCS Lab srl, Modena, Italy) 3D kinematic tracking system was used to evaluate and measure the scapular motion in 3 planes. All patients show substantial amount of posterior tilting and lateral rotation starting at 30° in forward elevation. A further difference is the anticipation of the retraction during the range of motion in the RSA side. The contribution of scapular motion in the RSA shoulder was greater than in the healthy shoulder. In patients with bilateral RSA, the contribution of scapular motion was higher in tilting and lateral rotation in the worse shoulder side in terms of range of motion. This means that to compensate for the loss of glenohumeral motion in RSA, more scapula-thoracic motion is needed to obtain the same thoraco-humeral elevation angle. In the light of what has been measured, the post-RSA scapular kinematics has typical characteristics that must be achieved in order to obtain a good functional outcome. We can conclude that on the RSA side, the patients anticipate upward rotation both in flexion and abduction. The contribution of the upward rotation to elevation in the RSA group is therefore more significant. In addition to this, to facilitate elevation movements, there is an anticipation of the scapular retraction and a more prominent tilt resulting in different scapular kinematics. The analysis of scapular motion could be useful in the postoperative follow-up of patients undergoing RSA surgery and improve adaptative physiotherapy protocols. It potentially can even be included in future arthroplasty planning systems.

The development and evaluation of an in-vitro shoulder simulator with active muscle simulation

The purpose of the present study was to develop a novel active in-vitro shoulder simulator to emulate all forms of planar and non-planar glenohumeral motions with active muscle simulation on cadaver specimens or shoulder models and to critically evaluate its performance. A physiologic shoulder simulator, driven using simulated muscle force, was developed to dynamically realize accurate kinematic control in all three rotational degrees of freedom (DOF) under physiological kinetic boundaries. The control algorithm of the simulator was implemented using three parallel running independent control loops, which regulate the forces of individual muscles in the respect DOF and work asynchronously in disparate sequences adapted to specific motions (abduction, flexion/extension and rotation). Three cadaveric specimens were used to evaluate the kinematic and kinetic performance of the simulator during simulated motions. High kinematic accuracy (maximum mean deviation ≤ 2.35° and RMSE 1.13°) and repeatability (maximum and average SD of ≤ 1.21° and 0.67°) were observed in all three rotational DOF investigated. The reliabilities of all individual muscle forces actuated in the simulator during planar and non-planar motions were generally excellent, with the 95% CIs of ICC estimates of > 0.90 for most instances (30/36). A novel shoulder simulator with active muscle simulation was developed and evaluated. Its capability to reproduce kinematics and kinetics in a physiological range for all DOF was systematically evaluated for multiple kinetic and kinematic outcome variables. The presented simulator is a powerful tool for investigating the biomechanics of physiological and pathological shoulder joints and to evaluate various surgical interventions. Acquisition of reliable data in joint kinetics and translational kinematics during active motions is critical to assess shoulder pathologies and appropriate treatments. We provide a unique muscle activated physiologic shoulder simulator, which allows the comprehensive acquisition of joint kinematic and kinetic data during repeated realistic planar and non-planar motions.

Glenohumeral joint trajectory tracking for improving the shoulder compliance of the upper limb rehabilitation robot.

Exoskeletons have become an important tool to help patients with upper extremity motor dysfunction in rehabilitation training and life assistance. In the study of the upper limb exoskeleton, the human glenohumeral joint will produce accompanying movement during the movement of the shoulder joint. This phenomenon causes a positional deviation between the shoulder joint and the exoskeleton, which affects the accuracy of exoskeleton-assisted human movement and the wearing comfort. Spend. Taking the coronal adduction and abduction of the shoulder joint as the research object, the shoulder joint angle and glenohumeral joint bony motion trajectory were fitted by bi-level X-rays, and then the Ultium Motion motion capture system was used to collect the characteristic motion of the shoulder joint surface and establish a model. A back-propagation neural network with shoulder joint motion and shoulder width as input and the coronal position of the glenohumeral joint as output, finally applied the model to the Nimbot exoskeleton upper limb rehabilitation training robot to verify the effectiveness of the algorithm. Real-time prediction of the glenohumeral joint motion trajectory was achieved, and the human-machine coupling compliance during the wearing of the upper limb exoskeleton was improved.

Biomechanical Characteristics of Scapular and Glenohumeral Movements during Pitching Motion in Injury-prone College Baseball Pitchers.

The coordination of glenohumeral (GH) and scapular movements is central to the injury prevention of baseball pitchers. However, there is no objective data establishing the direct relationship between pitching injuries and associated GH and scapular movements. Therefore, this study demonstrated the biomechanical differences in the scapular and GH movements during pitching between injury-prone pitchers and healthy college baseball pitchers. A total of 30 collegiate baseball pitchers were classified into two groups according to their injury status: injury-prone group (n = 15) and control group (n = 15). We obtained pitching motion data using three-dimensional motion analysis technique. The horizontal abduction angles of the GH joint during cocking and acceleration phases were considerably greater in the injury-prone pitchers (19.0° at stride foot contact [SFC], -4.0° at maximum external rotation [MER], and -0.3° at ball release) than those in healthy controls (11.7° at SFC, -10.0° at MER, and -6.9° at ball release). Additionally, in the cocking phase, the amount of angular change in the scapular external rotation (ER) was significantly smaller in the injury-prone group than that in the control group (mean difference, -13.0). These results suggest that the injury-prone pitchers have less internal rotation of the scapula and a more horizontal abduction of the GH joint during the cocking and acceleration phases. Therefore, sports medicine practitioners may need to pay considerable attention to the coordination of scapular and GH horizontal movements during pitching for prevention of shoulder injuries.

Arthroscopic Superior Capsular Reconstruction

Background: Limited options exist for young patients with massive, irreparable rotator cuff tears. While several treatment options exist, superior capsular reconstruction (SCR) was developed to restore glenohumeral joint stability by preventing superior humeral head migration during glenohumeral motion. Indications: Arthroscopic SCR is indicated in young patients with a massive, irreparable rotator cuff tear. Patients require a functioning deltoid muscle with minimal to no glenohumeral joint arthritis. In addition, patients should have Hamada grade 2 or less and should have an intact or repairable subscapularis tendon. Technique Description: The patient is positioned in the beach chair position. Standard anterior, posterior, and mid-lateral portals are established. An accessory posterior-superior lateral portal is used for visualization. Three 3.0 mm knotless anchors are placed in the glenoid through lateral percutaneous incisions. Two 4.75 mm anchors are placed adjacent to the humeral articular cartilage for medial row fixation. The graft dimensions are measured using the distance between the anchors. The graft is prepared using a gown card as a template with 5 mm added to the medial, posterior, and anterior graft dimensions, and 10 mm added to the lateral dimension. Sutures are passed through the graft in an inverted horizontal mattress for the glenoid anchors to diminish friction and allow appropriate suture passage through the knotless mechanism of the anchor. The graft is then shuttled into the joint through a lateral PassPort button cannula. Two lateral row anchors are used to secure the lateral graft on the humerus. Native rotator cuff tissue is repaired to the graft using sutures from the medial row anchors as well as free SutureTape. Results: Outcomes following SCR have demonstrated improvements in clinical outcomes and shoulder range of motion. Similar outcomes have been identified between the use of allograft and autograft. Patients generally are able to return to light recreational activities and work. Discussion/Conclusion: Arthroscopic SCR yields favorable results in the setting of a massive, irreparable rotator cuff tear. Meticulous surgical technique is needed to avoid intraoperative surgical complications. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Mechanistic insights into glenohumeral kinematics derived from positional relationship between the contact path and humeral tuberosity

Although three-dimensional (3D) glenohumeral (GH) motion has generally been expressed only by rotational elements, its mechanistic details, including GH rotations, remain unknown owing to a lack of geometric investigations. This study aims to investigate the positional relationship between the contact path and humeral tuberosities at the GH joint during arm elevation and to consider the mechanism of GH kinematics. Shoulder kinematics were captured using two-dimensional and 3D single-plane image registration techniques in 15 young healthy subjects during flexion, scaption, and abduction. The glenoid movement relative to the humeral head was calculated to describe the contact path on the humeral head. From the start to 45° of flexion, scaption, and abduction, the glenoid center moved from the anteromedial to the anterior, central, and posterior portions of the humeral head, respectively, as the GH joint rotated externally. From 45° to the maximal elevation for all elevation planes, the glenoid center moved upward to the humeral head and came close to the bicipital groove (BG) at maximal elevation, while the glenoid maintained a constant inclination at 20°–40° relative to the humerus. To investigate this mechanism, the position of humeral tuberosities relative to the glenoid was calculated, and the BG was found to face the supraglenoid tubercle, the attachment site of the long head of biceps (LHB). GH external rotation mainly occurred depending on the elevation planes in the early phase of elevation, and it might be kept constant by the LHB and rotator cuff in the mid- to end range of elevation.

A comparison of two surgical methods in the treatment of shoulder adhesive capsulitis.

The purpose of the study was to compare the outcomes of arthroscopic capsular release surgery and manipulation of patients with resistant primary adhesive capsulitis (AC) under anesthesia. The study comprised forty-four patients who had surgery after being given a diagnosis of primary AC. Patients who had both passive and active glenohumeral and scapulothoracic movements equal to or less than 100° elevation and less than 50% of external rotation compared to the contralateral side were considered to have resistant adhesive capsulitis and were included in the study. Conservative treatments such as intra-articular steroid injections and physical therapy had failed to relieve the pain in these patients for at least six months. The patients who took part in the trial underwent manipulation under anesthesia (group 1) and arthroscopic capsular release (group 2) operations. The chosen surgical procedure was chosen at random and based on the surgeon's preferences. examining the patients' demographic information. After treatment, the patients were examined at three-month, six-month, and one-year intervals. Joint range of motion, visual analogue scale (VAS), and Constant-Murley shoulder scores were all recorded. Statistics were used to compare the outcomes of the two surgical techniques in this study both before and after the procedure. The study's participants' gender, side, extra procedure, and age factors did not show a statistically significant difference between groups 1 and 2 (p<0.05). According to the age, gender, side, additional process, and homogeneous distribution throughout the groups. No statistically significant difference was discovered between groups 1 and 2 in any of the measurements taken from study participants during the follow-up period: Pre-op visual pain scores (VPS), Post-op 3rd month VPS, Post-op 1st year VPS, Pre-op Constant score, Post-op 6th month Constant score, and Post-op 1st year Constant score (p<0.05). The change in VPS and Constant Score values over time did not show a statistically significant difference between the groups (p<0.05). A statistically significant difference between the groups was discovered in each of the Pre-op period and Post-op 6th month VPS assessments (p<0.05). Although there was no statistically significant difference between the two studied therapies, the surgical method was shown to be more beneficial in both groups the shorter the pre-op period was between the onset of the complaints and the operation.