Glenohumeral Joint Instability Research Articles

Fatigue-related changes in intermuscular electromyographic coherence across rotator cuff and deltoid muscles in individuals with and without subacromial pain.

Neuromuscular fatigue induces superior migration of the humeral head in individuals with subacromial pain. This has been attributed to weakness of rotator cuff muscles and overactive deltoid muscles. Investigation of common inputs to motoneuron pools of the rotator cuff and deltoid muscles offers valuable insight into the underlying mechanisms of neuromuscular control deficits associated with subacromial pain. This study aims to investigate intermuscular coherence across the rotator cuff and deltoid muscles during a sustained submaximal isometric fatiguing contraction in individuals with and without subacromial pain. Twenty symptomatic and 18 asymptomatic young adults participated in this study. Surface electromyogram (EMG) was recorded from the middle deltoid (MD) and infraspinatus (IS). Intramuscular EMG was recorded with fine-wire electrodes in the supraspinatus (SS). Participants performed an isometric fatiguing contraction of 30° scaption at 25% maximum voluntary contraction (MVC) until endurance limit. Pooled coherence of muscle pairs (SS-IS, SS-MD, IS-MD) in the 2-5 Hz (delta), 5-15 Hz (alpha), and 15-35 Hz (beta) frequency bands during the initial and final 30 s of the fatigue task were compared. SS-IS and SS-MD delta-band coherence increased with fatigue in the asymptomatic group but not the symptomatic group. In the alpha and beta bands, SS-IS and SS-MD coherence increased with fatigue in both groups. IS-MD beta-band coherence was greater in the symptomatic than the asymptomatic group. Individuals with subacromial pain failed to increase common drive across rotator cuff and deltoid muscles and have altered control strategies during neuromuscular fatigue. This may contribute to glenohumeral joint instability and subacromial pain experienced by these individuals.NEW & NOTEWORTHY Through the computation of shared neural drive across glenohumeral muscles, this study reveals that individuals with subacromial pain were unable to increase shared neural drive within the rotator cuff and across the supraspinatus and deltoid muscles during neuromuscular fatigue induced by sustained isometric contraction. These deficits in common drive across the shoulder muscles likely contribute to the joint instability and pain experienced by these individuals.

Effect of patient-specific scapular morphology on the glenohumeral joint force and shoulder muscle force equilibrium: a study of rotator cuff tear and osteoarthritis patients.

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.

Children and adolescents with all forms of shoulder instability demonstrate differences in their movement and muscle activity patterns when compared to age- and sex-matched controls

BackgroundShoulder instability is a complex impairment and identifying biomarkers which differentiate subgroups is challenging. There is limited fundamental movement and muscle activity data for identifying different mechanisms for shoulder instability in children and adolescents which may inform subgrouping and treatment allocation. HypothesisChildren and adolescents with shoulder instability (irrespective of etiology) have differences in their movement and muscle activity profiles compared to age- and sex-matched controls (two-tailed). MethodsYoung people between eight to 18 years were recruited into two groups of shoulder instability (SI) or and age- and sex-matched controls (CG). All forms of SI were included and young people with co-existing neurological pathologies or deficits were excluded. Participants attended a single session and carried out four unweighted and three weighted tasks in which their movements and muscle activity was measured using 3D-movement analysis and surface electromyography. Statistical parametric mapping was used to identify between group differences. ResultsData was collected for 30 young people (15 SI (6M:9F) and 15 CG (8M:7F)). The mean (SD) age for all participants was 13.6 years (3.0). The SI group demonstrated consistently more protracted and elevated sternoclavicular joint positions during all movements. Normalized muscle activity in Latissimus dorsi was lower in the SI group and had the most statistically significant differences across all movements. Where differences were identified, the SI group also had increased normalized activity of their middle trapezius, posterior deltoid and biceps muscles whilst activity of their latissimus dorsi, triceps and anterior deltoid were decreased compared to the CG group. No statistically significant differences were found for pectoralis major across any movements. Weighted tasks produced fewer differences in muscle activity patterns compared to unweighted tasks. DiscussionYoung people with SI may adapt their movements to minimize glenohumeral joint instability. This was demonstrated by reduced variability in acromioclavicular and sternoclavicular joint angles, adoption of different movement strategies across the same joints and increased activity of the scapular stabilizing muscles, despite achieving similar arm positions to the CG. ConclusionYoung people with shoulder instability demonstrated consistent differences in their muscle activity and movement patterns. Consistently observed differences at the shoulder girdle included increased sternoclavicular protraction and elevation accompanied by increased normalized activity of the posterior scapula stabilizing muscles. Existing methods of measurement may be used to inform clinical decision making, however, further work is needed evaluate the prognostic and clinical utility of derived 3D and sEMG data for informing decision making within shoulder instability.

The moment arms and lines of action of subscapularis after the Latarjet procedure.

The Latarjet procedure is an established surgical treatment for recurrent glenohumeral joint instability with glenoid bone loss. Intraoperatively, the conjoint tendon and its attachement on the coracoid bone graft is routedthrough a split in subscapularis where the graft is fixed to and augments the anteroinferior glenoid. The objective of this in vitro study was to quantify the influence of glenohumeral joint position and conjoint tendon force on the lines of action and moment arms of subscapularis muscle sub-regions after Latarjet surgery. Eight fresh-frozen, entire upper extremities were mounted onto a testing apparatus, and a cable-pulley system was used to apply physiological muscle loading to the major shoulder muscles. The lines of action and moment arms of four subregions of subscapularis (superior, mid-superior, mid-inferior, and inferior) were quantified radiographically with the conjoint tendon unloaded and loaded while the shoulder was in (i) 0° abduction (ii) 90° abduction (iii) 90° abduction and full external rotation (ABER), and (iv) the apprehension position, defined as ABER with 30° horizontal extension. Conjoint tendon loading after Latarjet surgery significantly increased the inferior inclination of the lines of action of the mid-inferior and inferior subregions of subscapularis in the scapular plane in ABER and apprehension positions (p < 0.001), as well as decreased the horizontal flexion moment arm of the inferior subscapularis (p = 0.040). Increased subscapularis inferior inclination may ultimately increase inferior joint shear potential, while smaller horizontal flexion leverage may reduce joint flexion capacity. The findings have implications for Latarjet surgical planning and postoperative rehabilitation prescription.

Arthroscopic Fixation of Acute Large Bony Bankart with Suture-assisted Reduction and Screw Fixation - Surgical Technique.

Glenoid rim fractures with Bankart lesions are called bony Bankart lesions and are associated with persistent glenohumeral joint instability. Acute bony Bankart lesions can be treated by various arthroscopic techniques. Here, we present a technique of arthroscopic bony Bankart repair using suture-assisted reduction and screw fixation. The conventional suture anchor repair does not provide compression of the fractured fragment, and the bony piece may tilt because of the single-point fixation. This procedure can achieve firm compression between the bony fragments and prevent rotation of fragment during screw fixation to the glenoid. The capsular plication distributes the loads to the surrounding soft tissues. Hence, this procedure should be offered to all patients presenting acutely with a large bony Bankart of size >25% of glenoid width, as it is minimally invasive as well as provides excellent outcomes and anatomical union.

Fully automatic algorithm for detecting and tracking anatomical shoulder landmarks on fluoroscopy images with artificial intelligence

ObjectivePatients with rotator cuff tears present often with glenohumeral joint instability. Assessing anatomic angles and shoulder kinematics from fluoroscopy requires labelling of specific landmarks in each image. This study aimed to develop an artificial intelligence model for automatic landmark detection from fluoroscopic images for motion tracking of the scapula and humeral head.Materials and methodsFluoroscopic images were acquired for both shoulders of 25 participants (N = 12 patients with unilateral rotator cuff tear, 6 men, mean (standard deviation) age: 63.7 ± 9.7 years; 13 asymptomatic subjects, 7 men, 58.2 ± 8.9 years) during a 30° arm abduction and adduction movement in the scapular plane with and without handheld weights of 2 and 4 kg. A 3D full-resolution convolutional neural network (nnU-Net) was trained to automatically locate five landmarks (glenohumeral joint centre, humeral shaft, inferior and superior edges of the glenoid and most lateral point of the acromion) and a calibration sphere.ResultsThe nnU-Net was trained with ground-truth data from 6021 fluoroscopic images of 40 shoulders and tested with 1925 fluoroscopic images of 10 shoulders. The automatic landmark detection algorithm achieved an accuracy above inter-rater variability and slightly below intra-rater variability. All landmarks and the calibration sphere were located within 1.5 mm, except the humeral landmark within 9.6 mm, but differences in abduction angles were within 1°.ConclusionThe proposed algorithm detects the desired landmarks on fluoroscopic images with sufficient accuracy and can therefore be applied to automatically assess shoulder motion, scapular rotation or glenohumeral translation in the scapular plane.Clinical relevance statementThis nnU-net algorithm facilitates efficient and objective identification and tracking of anatomical landmarks on fluoroscopic images necessary for measuring clinically relevant anatomical configuration (e.g. critical shoulder angle) and enables investigation of dynamic glenohumeral joint stability in pathological shoulders.Key Points• Anatomical configuration and glenohumeral joint stability are often a concern after rotator cuff tears.• Artificial intelligence applied to fluoroscopic images helps to identify and track anatomical landmarks during dynamic movements.• The developed automatic landmark detection algorithm optimised the labelling procedures and is suitable for clinical application.

Clinical outcomes of primary Latarjet technique in recurrent shoulder dislocation using BioLatarjet® LCS cannulated flat head screws

Background: The Latarjet technique is an effective procedure that reconstructs and augments the glenohumeral joint instability. It improves stability by increasing the glenoid width and using the sling effect. The aim of the study was to assess the functional outcomes of the primary Latarjet treatment with BioLatarjet® LCS cannulated flat head screws in cases of recurrent shoulder dislocation. Methods: In this retrospective study, 30 patients were treated with the primary Latarjet technique. Rowe score, visual analog scale (VAS), Quebec back pain disability scale (QDS), and, American shoulder and elbow surgeon score (ASES), and range of motion (ROM) were evaluated in the selected population at the time point of 6-week, 3-month, and 6-month after surgery for the determination of the functional outcomes in them. Results: The results showed that all patients had excellent or good functional outcomes with significant improvements in Rowe score, VAS score, QDS, and ASES scores (p&lt;0.0001). The ROM in patients for forward elevation, cross body adduction, external rotation by side of body/neutral, and internal rotation by side of body/neutral were related to better clinical outcome and less movement of recurrent instability with optimal graft placement. Conclusions: These findings have clinical significance in that they demonstrate the effectiveness of the Latarjet technique in improving stability without significantly increasing the risk of complications. The BioLatarjet® LCS cannulated flat head screws were found to be safe and efficient for primary Latarjet surgeries, providing appropriate graft healing and a low recurrence of instability, with a good return-to-sports rate.

Scapulothoracic tenodesis using hamstring tendon graft for treatment of problematic scapula winging: A new surgical technique.

Winging of the scapula occurs due to dysfunction of its stabilising muscles, most commonly serratus anterior and/or trapezius, for example in facioscapulohumeral muscular dystrophy. Resultant loss of scapular control and abnormal kinematics can decrease shoulder function due to glenohumeral joint instability, loss of range of motion and pain. Previously described treatment for cases resistant to physiotherapy includes scapulothoracic arthrodesis which involves risk of non-union and metalwork failure, as well as reduced respiratory function due to immobilisation of a segment of the adjacent chest wall. We present a novel surgical approach to the management of problematic scapular winging by using hamstring graft to achieve a scapulothoracic tenodesis. We believe this technique provides an adequately stable scapula for improved shoulder movement and function, a sufficiently mobile chest wall for improved lung function and avoidance of complications specifically associated with arthrodesis.

Managing Shoulder Instability in the Overhead Athlete.

Shoulder instability in the overhead athlete is a difficult problem because of the balance between necessary laxity for athletic movements and stability of the joint. The purpose of this review is to provide an overview of the clinical evaluation of shoulder instability in the overhead athlete and present evidence-based management strategies for each subtype of shoulder instability, including novel techniques and outcomes. Recent investigation has shown that throwers and other overhead athletes are more likely to present with subtle subluxation events rather than discrete dislocations as their primary symptom. While overhead athletes with discrete anterior dislocation events are likely to begin with non-operative management, many progress on to surgical intervention. Surgical management of glenohumeral joint instability continues to pose challenges due to the potential for over-tensioning for the sake of stability at the expense of the adaptive laxity that often confers performance benefits in the overhead athlete. Novel, individualized, and sport/position specific approaches are needed to address this complex issue. The optimal management of shoulder instability in the overhead athlete continues to be a controversial topic due to the complex work-up, an increasing number of surgical options with varying indications, and low volume of high-quality studies comparing any of the treatment options. The Anterior Shoulder Instability International Consensus Group guidelines from February 2022 offer the most updated guidelines on work-up and management. Overall, high-quality randomized controlled trials are required to determine the optimal treatment for specific pathologies and aid in creating patient-centered management plans.

Kinesio taping with ballistic six plyometric training on speed, accuracy, target and joint proprioception in fast bowlers with glenohumeral instability

Cricket is one of the most popular international sports played worldwide. Ballistic six plyometric training improves throwing activity in throwing sports, improves rotator cuff muscular strength, and prevents and reduces the risk of shoulder injury associated with overhead pitching. Kinesiotaping is used in rehabilitation, as a treatment for sportsrelated injuries, and as a means of injury prevention. The objective of the study was to compare the combined effect of kinesiotaping with ‘ballistic six plyometric training’ and with ballistic six plyometric training alone on speed, accuracy, target and joint proprioception in fast bowlers with mild glenohumeral joint instability. Thirty male semiprofessional fast bowlers in the age group of 20-30 years were included in this study and randomly divided into two groups: group A and group B with 15 players in each group. Group A received kinesiotaping along with ballistic six plyometric training, whereas group B was only given ballistic six plyometric training. Both groups also performed conventional upper extremity workouts. All players were evaluated for bowling speed, accuracy, target and joint proprioception (internal rotation &amp; external rotation) with a radar gun, cricket specific bowling accuracy test, no. of balls hit stump in an over and inclinometer, respectively. Both groups improved significantly at the end of week 8, however, group B showed significant difference for bowling speed, accuracy, target and joint proprioception (P&lt;0.05). Rehabilitation protocol comprising of combined kinesiotaping, plyometrics along with conventional protocol can be beneficial in enhancing performance related variables, i.e. bowling speed, accuracy and target in fast bowlers with mild glenohumeral instability.

The humeral suspension technique: a novel operation for deltoid paralysis.

Isolated deltoid paralysis is a rare pathology that can occur after axillary nerve injury due to shoulder trauma or infection. This condition leads to loss of deltoid function that can cause glenohumeral instability and inferior subluxation, resulting in rotator cuff muscle fatigue and pain. To establish dynamic glenohumeral stability, a novel technique was invented. Humeral suspension is achieved using a double button implant with non-resorbable high strength cords between the acromion and humeral head. This novel technique was used in two patients with isolated deltoid paralysis due to axillary nerve injury. The results indicate that the humeral suspension technique is a method that supports centralizing the humeral head and simultaneously dynamically stabilizes the glenohumeral joint. This approach yielded high patient satisfaction and reduced pain. Glenohumeral alignment was improved and remained intact 5 years postoperative. The humeral suspension technique is a promising surgical method for subluxated glenohumeral joint instability due to isolated deltoid paralysis.

Evaluation of Scapula and Humerus Bone Change after Repair of Small- to Medium-Sized Rotator Cuff Tears: Comparison between Healing and Retear Groups Using Three-Dimensional Computed Tomography.

Rotator cuff tendon retears after rotator cuff repair cause glenohumeral joint instability, which results in changes in the glenoid and humerus head. However, limited data are available on the bone change after repair of small- to medium-sized rotator cuff tears. The aim of this study was to evaluate the difference of glenoid and humerus bone changes between healing and retear groups after repair of small- to medium-sized rotator cuff tears. Among patients who had arthroscopic repair due to small- to medium-sized rotator cuff tears from January 2009 to January 2017, 49 patients who underwent both preoperative and postoperative (at least 3 years after surgery) shoulder computed tomography were enrolled. Using three-dimensional reconstruction program (3D Slicer) and shape analysis program (SlicerSALT), we compared the occurrence and degree of glenoid bone change, glenoid inclination change, retroversion change, and glenoid center, as well as the degree of humerus head change, between the healing and retear groups. The occurrence of glenoid bone change was significantly more common in the retear group than in the healing group (p = 0.026). The degree of bone change in the 11-1 o'clock axial plane and 10-8 o'clock, 11-7 o'clock, and 12-6 o'clock coronal plane and the degree of glenoid inclination change were significantly larger in the retear group than the healing group (p = 0.026, p = 0.026, p = 0.026, p = 0.026, and p = 0.014, respectively), but the average value of glenoid bone change in the retear group was within the range of 0.14 to 1.01 mm for each plane. The mean humeral head change was 5.69 ± 3.67 mm increase in the retear group and 1.27 ± 2.02 mm increase in the healing group. Compared with the healing group, the retear group showed statistically significantly increased humeral head change (p < 0.001). There was difference in glenoid and humerus bone change between the healing and retear groups at midterm follow-up after repair of small- to medium-sized tears. However, considering the measurement bias, the difference between the two groups was within the measurement error range.

Results of Arthroscopic Remplissage with Bankart Repair for the Management of Glenohumeral Instability with Hill-Sachs Bone Defect

Glenohumeral joint instability is one of the commonest disorders of the shoulder as it has a great range of motion on the expense of stability as refered to the bony configuration of the joint. Instability may be traumatic or atraumatic and uni-directional or multidirectional with wide range of patient complaints from mild pain in micro-instability to obvious dislocation. The most commonly used arthroscopic procedure include filling the humeral head defect by capsulo-tenodesis of the infraspinatus tendon and posterior capsule (Remplissage). The aim of this study was to present our results of Bankart repair and Reimplissage in management of recurrent shoulder instability with Hill-Sachs lesions. 20 young, middle age and fit patients with recurrent anterior shoulder dislocation with combined Bankart lesion and Hill-Sachs lesion. All Hill-Sachs lesions were large or engaging (Calandra grade 3 at time of arthroscopy) and all were managed by arthroscopic Bankart repair combined with Remplissage. When compared to pre-operative ROM, a statistically significant difference was found in the mean increase of anterior elevation by 2°, external rotation (ER) side by 4◦ and 5° for ER at 90° abduction at final follow-up (p value < 0.001). There were statistically significant difference in the mean decrease of 5° and 10° in ER side and ER at 90° abduction respectively at final follow-up compared to normal side ROM (p value < 0.001), also significant decrease in anterior elevation by 4° and IR at 90° abduction by 2° (p value < 0.001) which were not comparable to other studies but was clinically insignificant. The mean final Rowe and SST scores were 85 and 11.35 respectively indicating a statistically significant difference in mean increase of both the total Rowe and total SST percentage score when compared to pre-operative scores (p value < 0.001). All patients were followed prospectively for a minimum of 12 months. Conclusion: arthroscopic Bankart repair and remplissage is an effective means of managing shoulder instability in patients with large Hill-Sachs lesions and no significant glenoid bony defect.

Complications of Reverse Total Shoulder Arthroplasty: A Computational Modelling Perspective.

Reverse total shoulder arthroplasty (RTSA) is an established treatment for elderly patients with irreparable rotator cuff tears, complex proximal humerus fractures, and revision arthroplasty; however, with the increasing indications for RTSA over the last decade and younger implant recipients, post-operative complications have become more frequent, which has driven advances in computational modeling and simulation of reverse shoulder biomechanics. The objective of this study was to provide a review of previously published studies that employed computational modeling to investigate complications associated with RTSA. Models and applications were reviewed and categorized into four possible complications that included scapular notching, component loosening, glenohumeral joint instability, and acromial and scapular spine fracture, all of which remain a common cause of significant functional impairment and revision surgery. The computational shoulder modeling studies reviewed were primarily used to investigate the effects of implant design, intraoperative component placement, and surgical technique on postoperative shoulder biomechanics after RTSA, with the findings ultimately used to elucidate and mitigate complications. The most significant challenge associated with the development of computational models is in the encapsulation of patient-specific anatomy and surgical planning. The findings of this review provide a basis for future direction in computational modeling of the reverse shoulder.

Capsulolabral Reconstruction During the Open Latarjet Procedure

Surgical treatment of anterior glenohumeral joint instability can be challenging and carries the inherent risk of recurrent instability, dislocation arthropathy, and postoperative loss of external rotation. In the current manuscript, a technique for combined reconstruction of anterior labrum and capsule, with concomitant reduction of the humeral head during anterior capsule reconstruction in open Latarjet procedure, is presented. Analogous to other techniques, the coracoid graft is fixed on the anteroinferior part of the glenoid between 3 and 5 o'clock. However, for this technique, reattachment of the labrum is performed between the native glenoid and the bone graft. Additionally, during the reconstruction of the anterior capsule on the coracoacromial ligament, while the operated arm is held in external rotation to avoid the postoperative rotational deficit, the humeral head is reduced posteriorly in the center of the glenoid during adduction, slight anterior forward flexion, and a posterior lever push. By doing so, the inherent theoretical risks of persistent instability and dislocation arthropathy are believed to be decreased. Further studies are needed to clarify the long-term consequences of this surgical technique in the clinical setting.

Progressive exercise compared with best practice advice, with or without corticosteroid injection, for the treatment of patients with rotator cuff disorders (GRASP): a multicentre, pragmatic, 2 × 2 factorial, randomised controlled trial

SummaryBackgroundCorticosteroid injections and physiotherapy exercise programmes are commonly used to treat rotator cuff disorders but the treatments' effectiveness is uncertain. We aimed to compare the clinical effectiveness and cost-effectiveness of a progressive exercise programme with a single session of best practice physiotherapy advice, with or without corticosteroid injection, in adults with a rotator cuff disorder.MethodsIn this pragmatic, multicentre, superiority, randomised controlled trial (2 × 2 factorial), we recruited patients from 20 UK National Health Service trusts. We included patients aged 18 years or older with a rotator cuff disorder (new episode within the past 6 months). Patients were excluded if they had a history of significant shoulder trauma (eg, dislocation, fracture, or full-thickness tear requiring surgery), neurological disease affecting the shoulder, other shoulder conditions (eg, inflammatory arthritis, frozen shoulder, or glenohumeral joint instability), received corticosteroid injection or physiotherapy for shoulder pain in the past 6 months, or were being considered for surgery. Patients were randomly assigned (centralised computer-generated system, 1:1:1:1) to progressive exercise (≤6 sessions), best practice advice (one session), corticosteroid injection then progressive exercise, or corticosteroid injection then best practice advice. The primary outcome was the Shoulder Pain and Disability Index (SPADI) score over 12 months, analysed on an intention-to-treat basis (statistical significance set at 1%). The trial was registered with the International Standard Randomised Controlled Trial Register, ISRCTN16539266, and EuDRACT, 2016-002991-28.FindingsBetween March 10, 2017, and May 2, 2019, we screened 2287 patients. 708 patients were randomly assigned to progressive exercise (n=174), best practice advice (n=174), corticosteroid injection then progressive exercise (n=182), or corticosteroid injection then best practice advice (n=178). Over 12 months, SPADI data were available for 166 (95%) patients in the progressive exercise group, 164 (94%) in the best practice advice group, 177 (97%) in the corticosteroid injection then progressive exercise group, and 175 (98%) in the corticosteroid injection then best practice advice group. We found no evidence of a difference in SPADI score between progressive exercise and best practice advice when analysed over 12 months (adjusted mean difference −0·66 [99% CI −4·52 to 3·20]). We also found no evidence of a difference between corticosteroid injection compared with no injection when analysed over 12 months (−1·11 [–4·47 to 2·26]). No serious adverse events were reported.InterpretationProgressive exercise was not superior to a best practice advice session with a physiotherapist in improving shoulder pain and function. Subacromial corticosteroid injection provided no long-term benefit in patients with rotator cuff disorders.FundingUK National Institute for Health Research Technology Assessment Programme.

Functional cortical changes associated with shoulder instability - a systematic review.

Glenohumeral joint instability is associated with structural deficits and/or alterations in sensory and motor processing; however, a proportion of patients with glenohumeral joint instability fail to respond to surgical and rehabilitative measures. This systematic review aimed to establish if functional cortical changes occur in patients with glenohumeral joint instability. AMED, CINAHL, Cochrane Central Register of Controlled Trials, Embase, Medline, PEDro, Pubmed, PsychINFO and Scopus were searched from inception to 17 March 2021. Randomised controlled trials and non-randomised trials were included and quality was appraised using the Downs and Black tool. One thousand two hundred seventy-nine records were identified of which five were included in the review. All studies showed altered cortical function when comparing instability patients with healthy controls and included areas associated with higher cortical functions. The findings of this systematic review offer some insight as to why interventions addressing peripheral pathoanatomical factors in patients with glenohumeral joint instability may fail in some cases due to functional cortical changes. However, data are of moderate to high risk of bias. Further high-quality research is required to ascertain the degree of functional cortical changes associated with the type and duration of glenohumeral joint instability.

Postoperative Rehabilitation of Posterior Glenohumeral Joint Instability Surgery: A Systematic Review.

Posterior glenohumeral (GH) joint instability is uncommon compared with anterior and multidirectional instability. A variety of surgical techniques are used to treat posterior GH instability. As a result, there are numerous rehabilitation protocols that vary greatly. The objective of this review was to define, evaluate and compare the postsurgical rehabilitation protocols for patients treated surgically for posterior GH instability. The review contains articles that outline a rehabilitation protocol following a surgical repair of posterior GH instability. A multidatabase search was conducted. Two independent, blinded reviewers decided on inclusion and exclusion of each study, with a second round to resolve conflicts. Data was extracted from the pertinent studies after the grading of evidence was conducted by 2 reviewers. Sixteen studies of the original 859 were included. Most studies included a 3-phase to 4-phase protocol that consisted of immobilization, remobilization, strength training, and sport-specific training. A review of current literature shows a paucity of high-quality studies regarding outcomes of rehabilitation following surgery for posterior GH instability. Most studies had favorable results, with most patients returning to their presurgical level of activity.

Four-dimensional computed tomography evaluation of the shoulder joint in baseball players

Glenohumeral (GH) joint instability and internal impingement have been recognized as causes of shoulder pain in throwing athletes; however, in vivo GH joint kinematics is controversial. The GH contact patterns reflect joint pathogeneses.

Anterior glenohumeral instability: Current review with technical pearls and pitfalls of arthroscopic soft-tissue stabilization.

The glenohumeral joint (GHJ) allows for a wide range of motion, but is also particularly vulnerable to episodes of instability. Anterior GHJ instability is especially frequent among young, athletic populations during contact sporting events. Many first time dislocators can be managed non-operatively with a period of immobilization and rehabilitation, however certain patient populations are at higher risk for recurrent instability and may require surgical intervention for adequate stabilization. Determination of the optimal treatment strategy should be made on a case-by-case basis while weighing both patient specific factors and injury patterns (i.e., bone loss). The purpose of this review is to describe the relevant anatomical stabilizers of the GHJ, risk factors for recurrent instability including bony lesions, indications for arthroscopic vs open surgical management, clinical history and physical examination techniques, imaging modalities, and pearls/pitfalls of arthroscopic soft-tissue stabilization for anterior glenohumeral instability.