Posterior Glenohumeral Joint Research Articles

The Posterior Shoulder Instability Questionnaire: internal consistency, content and criterion validity, responsiveness, and reliability of a new tool for the assessment of posterior shoulder instability

Posterior shoulder instability (PSI) is an increasingly recognized cause of shoulder dysfunction particularly in young active patients and certain athlete populations. When evaluating the efficacy of treatment for PSI, specific outcome measures for this population are essential. The aim of the current research was to describe the development and evaluation of a patient reported outcome measure (PROM) specific for PSI. A retrospective cohort study design of patients with PSI was used to develop and evaluate the "Posterior Shoulder Instability Questionnaire (PSI-Q)". Items for PSI-Q were generated through an expert focus group and existing questionnaires. Preliminary data analysis identified redundancy of items and resulted in the PSI-Q being refined. The final PSI-Q was evaluated on 128 patients with PSI with a structural lesion requiring surgical intervention. Participants were excluded in the absence of a posterior glenohumeral joint lesion. Internal consistency (Cronbach α and corrected item-total correlation), content validity, criterion validity, responsiveness, and test-retest reliability (intraclass correlation coefficient; ICC) were examined. Content validity, criterion validity and responsiveness were compared with the Melbourne Instability Shoulder Score (MISS) and the Western Ontario Shoulder Index (WOSI). The minimum detectable change score (MDC) was calculated. The Cronbach α for the total scale pre and post-intervention was high (α = 0.97). All five domains (Pain, Instability/Weakness/Stiffness, Function, Occupation and Sport, and Quality of Life and Satisfaction) demonstrated acceptable internal consistency for each subsection and the overall score of the scale (α > 0.70). The corrected-item total correlation for each domain were within an acceptable range. The responsiveness of the PSI-Q questionnaire was excellent (effect size, 2.06; standard response mean, 1.34) and was higher than the MISS and WOSI. There were no relevant floor effects and one ceiling effect. Reliability was excellent (ICC (1,1) = 0.93) and the calculated MDC was 10.9 points. This study designed and validated a questionnaire specific for measuring symptoms and function in people with structural PSI requiring surgery. The PSI-Q demonstrates good measurement properties and provides an MDC that is useful for researchers and clinicians. In structural PSI, the PSI-Q has a higher responsiveness and more accurately reflects a patient's overall perceived shoulder status compared to current patient reported outcomes for shoulder instability. The psychometric properties of the PSI-Q are still to be determined in a non-surgical population.

Combined Effects of Glenohumeral Mobilization, Stretching, and Thoracic Manipulation on Shoulder Internal Rotation Range of Motion.

Interventions including posterior glenohumeral mobilizations (PGM), sleeper stretches, and thoracic manipulation are commonly used to address posterior shoulder tightness. The purpose of this study was to assess the effects of adding thoracic manipulation to PGM and sleeper stretches on passive range of motion (PROM), joint mobility, and infraspinatus electromyographic (EMG) activity in shoulders with decreased internal rotation (IR) PROM. Randomized Sequential Intervention Laboratory Study. Forty individuals with clinically significant IR loss attended two study sessions. Participants were randomized to receive five 30 seconds bouts of either grade III PGM or sleeper stretching. Following a seven-day washout period, all participants attended a second session and received a prescriptive supine HVLA manipulation targeting the T3-4 segment, followed by the previously randomized intervention. Outcome measures included internal rotation PROM, horizontal adduction PROM, posterior glenohumeral joint translation assessed via ultrasound imaging, and EMG activity of the infraspinatus during a PGM. All outcome measures were assessed pre- and immediately post-intervention and compared statistically. There were significant within-group, but not between-group, differences for IR and horizontal adduction PROM following a single session of PGM or sleeper stretch. When combined with thoracic manipulation, significantly smaller within session changes of IR PROM were observed for both PGM (mean difference 4.4, p=0.017) and sleeper stretches (mean difference 6.4, p=0.0005). There were no significant between group differences for horizontal adduction PROM, humeral head translation, or EMG activity across all time points. Both GH posterior mobilizations and sleeper stretches improved IR and horizontal adduction PROM in a single session. The addition of thoracic manipulation prior to local shoulder interventions resulted in smaller gains of both IR and horizontal adduction ROM. Level 2.

Clinical Implication of Glenohumeral and Subacromial Synovitis in Rotator Cuff Tears.

Synovitis of the glenohumeral (GH) joint and the subacromial (SA) space is commonly observed during arthroscopic rotator cuff surgery. To investigate the distribution, severity, and clinical implications of synovitis in the GH joint and SA space in patients with a full-thickness rotator cuff tear (RCT). Case series; Level of evidence, 4. Data were retrospectively collected from 207 patients with a full-thickness RCT who underwent arthroscopic repair. Preoperative parameters used in the clinical assessment included pain, range of motion (ROM), muscle strength, and functional scores. Macroscopic assessment of synovitis was performed intraoperatively in the 3 regions of interest (ROIs) of the GH joint and 4 ROIS of the SA space using an evaluation system. The distribution and severity of synovitis and the association between synovitis and clinical assessment were evaluated. Synovitis was more severe in the GH joint than in the SA space (P < .001). Synovitis in the posterior GH joint and the lateral SA space, where most of the rotator cuff was located, was the most severe area among the ROIs of the GH joint and the SA space, respectively (P < .05). All types of pain, except for pain at rest, were associated with synovitis in the posterior GH joint (P < .05). All ROM measures were associated with synovitis in the posterior and inferior GH joint (|r| > 0.20; P < .05 for both). The strength of the supraspinatus and the infraspinatus was associated with synovitis in the posterior GH joint (P < .05). Shoulder function was associated with synovitis in the posterior and inferior GH joint and more in the posterior GH joint (P < .05 for both). Synovitis in the SA space was not associated with any of the clinical parameters. Synovitis in the posterior GH joint was the most severe form of synovitis in the GH joint in patients with a full-thickness RCT. Synovitis in the posterior GH joint was closely associated with increased pain and decreased ROM, muscle strength, and functional score. Synovitis in the SA space was milder and not associated with any clinical parameters.

Creating an Inexpensive PVC Shoulder Model for the Training of Ultrasound-Guided Posterior Glenohumeral Joint Injections.

Ultrasound-guided injections are used to treat common shoulder pathologies and have been shown to be more accurate and effective than traditional landmark-guided procedures. Currently, there exists no inexpensive shoulder model that accurately simulates the anatomical structures of the shoulder while also facilitating glenohumeral joint (GHJ) injection. Our model is an alternative to the traditional bedside training and provides a low-risk training environment. We created this model from easily accessible materials. Polyvinyl chloride pipe was used to create the skeletal infrastructure pectoral girdle. A detergent pod was used to represent the GHJ space. Steaks were used to simulate the infraspinatus and deltoid muscles, with meat glue as a fascial layer between the two simulated muscles. Total cost of materials for the model was $19.71. Our model successfully replicates known anatomical features of the GHJ. Additionally, the model facilitates injection into a GHJ space, representing a GHJ injection. Our model was replicated to train medical student practitioners during five different educational sessions. The model was validated through comparison to standardized educational ultrasound training videos. It was further validated by ultrasound experts. The shoulder model we created is effective in simulating GHJ injections under ultrasound guidance. It simulates realistic muscle and bony landmarks both for ultrasound imaging and injection feel. Importantly, it is inexpensive and easy to replicate allowing more access to medical practitioners and students to be educated on the procedure.

The Thumb Test: A Simple Physical Examination Maneuver for the Diagnosis of Symptomatic Posterior Shoulder Instability

Posterior shoulder instability is becoming increasingly recognized in young active patient populations. Diagnosing posterior instability can be challenging because patients commonly present with a complaint of pain without a history of a dislocation or subluxation event. Additionally, a posterior labral tear is not always clearly visualized on advanced imaging studies. As such, physical examination is critical to the diagnosis. We report a simple physical examination maneuver for the diagnosis of symptomatic posterior shoulder instability. The thumb test attempts to replicate a posterior bone block procedure, helping to re-establish stability and relieve pain. The examiner places his or her thumb over the posterior glenohumeral joint line while the patient actively forward elevates the affected arm overhead. Improvement in pain and stability with this maneuver is diagnostic for symptomatic posterior shoulder instability. This test augments current physical examination maneuvers to assist with correctly diagnosing posterior shoulder instability.

Comparison of Gene Expression of Inflammation- and Fibrosis-Related Factors Between the Anterior and Posterior Capsule in Patients With Rotator Cuff Tear and Shoulder Stiffness.

Background:Arthroscopic capsular release is an effective treatment for refractory shoulder stiffness, yet there are no basic studies that can explain the extent of the release.Purpose:This study aimed to compare the genetic expression of inflammation- and fibrosis-related factors between the anterior and posterior capsules in patients with shoulder stiffness and rotator cuff tear.Study Design:Descriptive laboratory study.Methods:Enrolled in this study were 35 patients who underwent arthroscopic capsular release for shoulder stiffness along with the rotator cuff repair. Anterior and posterior glenohumeral joint capsular tissues were obtained during the capsular release. For the control tissue, anterior capsule was obtained from 40 patients without stiffness who underwent arthroscopic rotator cuff repair. The gene expression of collagen types I and III, fibronectin, extracellular matrix, basic fibroblast growth factor, transforming growth factor–β, connective tissue growth factor, matrix metalloproteinase (MMP)-1, MMP-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1, TIMP-2, intercellular adhesion molecule 1, interleukin 1, and tumor necrotizing factor–α were analyzed using real-time reverse transcription polymerase chain reaction. Differences in gene expression between the anterior capsule, the posterior capsule, and the control tissue were compared with the Kruskal-Wallis test.Results:The expression levels of collagen types I and III were significantly higher in the anterior capsule with stiffness com (pared with both the posterior capsule with stiffness (P = .010 for both) and the control (P = .038 and .010, respectively). The levels of fibronectin, MMP-2, and MMP-9 in the anterior capsule were significantly higher than in both the posterior capsule (P = .013, .003, and .006, respectively) and the control (P = .014, .003, and .005, respectively).Conclusion:Genetic analysis of the shoulder capsule revealed that more fibrogenic processes occur in the anterior capsule compared with the posterior capsule in patients with shoulder stiffness.Clinical Relevance:Capsular release for shoulder stiffness should be more focused on the anterior capsule than on the posterior capsule.

Neuromuscular Ultrasound P-NU001. Ultrasound assessment for shoulder pain: Evaluation of etiology in urban area of Jakarta

Introduction . Shoulder pain is the third most common cause of musculoskeletal problems with chronicity and high recurrence rate. Due to its superficial location, Ultrasound imaging (US) can be used to assess associated pathological conditions. We try to identify the frequency of US-diagnosed shoulder disorders in our clinical practice. Methods . We reviewed and analysed 49 shoulder ultrasound reports of patients with shoulder pain (sub-acute and chronic) from our neurology department in MRCCC Siloam Hospitals Jakarta. All of the patients were referred to radiology department after initial assessment from neurologist. Patients were assessed for their biceps tendon, subscapularis tendon, supraspinatus tendon, infraspinatus and teres minor tendon and also evaluated for acromioclavicular joint and posterior structures such as posterior glenohumeral joint recess. Results . The most frequently diagnosed pathology was calcified (chronic) tendinopathy (30.6%), followed by non-calcified tendinopathy (22.4%), subacromial-subdeltoid bursitis (22.4%), acromioclavicular (AC) joint stenosis (14.3%), and miscellaneous disorders such as lipoma and fibroma (4.1%). There were 3 cases (6.2%) where no specific disorder was found. In the tendinopathy group (calcified and non-calcified), long biceps tendon was the most frequently affected tendon (46.4%), followed by supraspinatus tendon (39.3%) and subscapularis tendon (14.3%). Conclusion . Among patients presenting with shoulder pain, tendinopathy is the most common disorder found using ultrasound assessment of shoulder, followed by bursitis, and acromioclavicular joint stenosis.

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.

Effect of Arm Position on Visualization of Target Zone for Posterior Glenohumeral Joint Injection

Objectives: Glenohumeral injections can be performed using a variety of approaches. We hypothesize that the position of the ipsilateral arm affects the target zone for posterior approach of glenohumeral joints. Material and Methods: We performed ultrasound on three volunteers with arm with in neutral and varying degrees of flexion and extension. Results: We found that target zone is increased on flexion and decreased with arm in extension. Conclusion: Considering patient comfort, target zone, and operator ergonomics, we conclude that the posterior glenohumeral US-guided injections should be performed with patient lying on the contralateral side with the ipsilateral arm in neutral, and hand rested on the thigh (Birmingham Royal Orthopedic Hospital (BROH) position).

New Reduction Technique for Traumatic Posterior Glenohumeral Joint Dislocations.

Traumatic posterior glenohumeral joint (GHJ) dislocation is a rare condition which can be missed if it is not suspected. Clinical presentation may be subtle, but limitation in range of motion in patient with acute trauma should warrant obtaining a thorough history, performing a comprehensive physical examination, and acquiring at least a 3-view plain radiography. Reduction can be achieved with a direct pressure to the posterior aspect of the humeral head.

Microdialysis to Quantify Inflammatory Cytokines in the Glenohumeral Joint: A Brief Methods Report.

Microdialysis quantifies in vivo soft-tissue biochemical concentrations via passive diffusion of interstitial molecules through a porous membrane into a dialysate. The purpose of this pilot study was to evaluate a technique to measure inflammatory cytokines associated with rotator cuff tendinopathy by inserting a microdialysis catheter into the posterior glenohumeral joint. The technique was tested in a convenience sample of six pain-free, able-bodied veterans. Complete dialysate samples were collected in two participants. Two participants' sample volumes were smaller than what was required for analysis (30 μl) and thus were diluted. Catheter failures in two participants prevented collection altogether. Three cytokine concentrations were quantified: interleukin-1 receptor antagonist, interleukin 8, and regulated on activation, normal T-cell expressed and secreted. Microdialysis is not recommended for use in the glenohumeral joint, yet quantification of glenohumeral joint cytokines could yield valuable information to better understand pathophysiology of the joint and its surrounding tissues. Another technique, such as joint lavage, may be a more attractive alternative to overcome the limitations of microdialysis in the glenohumeral joint.

A 3D Anatomical Investigation of the Suprascapular Nerve: A Needle Placement Study for Radiofrequency Denervation of the Glenohumeral Joint

BackgroundThe suprascapular nerve (SSN) is the main target for image‐guided denervation to manage chronic glenohumeral joint pain related to osteoarthritis. The suprascapular notch has been used as a landmark to completely denervate the SSN; however, this approach also results in paralysis of supraspinatus (SS) and infraspinatus. To propose function‐preserving denervation protocols, a detailed understanding of the suprascapular nerve branches and their relationship to bony and soft tissue landmarks are required.ObjectivesThe objectives of this study were to: 1) define the course of SSN and its branches in relation to bony and soft tissue landmarks visible with image‐guidance; 2) propose a novel denervation protocol based on anatomical findings; and 3) evaluate the needle placement and nerve capture rate of the proposed protocol.MethodsThe SSN and its branches were meticulously dissected from the suprascapular notch to the spinoglenoid notch in 15 formalin‐embalmed specimens. The course of SSN and its branches was documented relative to bony or soft tissue landmarks visible with image‐guidance. The innervation patterns and landmarks were used to develop a SS function sparing denervation protocol. The protocol was evaluated in a needle placement pilot study using 3 lightly embalmed specimens. Radiofrequency needles were placed using ultrasound guidance. Then, the SSN and its branches and needle tip were exposed, digitized and modeled in 3D. The lesion diameter was generated at the needle tip to evaluate nerve capture rate.ResultsIn all 15 specimens, SSN and its branches course along the floor of the supraspinous fossa deep to SS. After coursing through the suprascapular notch, SSN immediately bifurcated into medial and lateral trunks. The medial trunk of SSN coursed medially to supply motor innervation to the anterior region of SS. The lateral trunk coursed laterally along the floor of the supraspinous fossa, around the spinoglenoid notch, to the infraspinatus. The lateral trunk supplied: 1) motor innervation to the posterior region of SS; and 2) 1–4 sensory articular branches to the posterior glenohumeral joint capsule. The articular branches originated from the lateral trunk in the region of the midpoint of a line connecting the suprascapular and spinoglenoid notches. When this midpoint landmark was used, for ultrasound‐guided radiofrequency needle placement, the lateral trunk of SSN and its articular branches were captured while the medial trunk was spared, in all specimens.ConclusionsThis cadaveric study provides evidence that the medial trunk of SSN could be spared, while the posterior glenohumeral joint capsule would be denervated, by targeting the lateral trunk, at the midpoint of a line connecting the suprascapular and spinoglenoid notches. With sparing of medial trunk, SS may retain partial abduction function. Further clinical investigation is required to assess functional and pain relief outcomes.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The aetiology of posterior glenohumeral dislocations and occurrence of associated injuries: a systematic review.

The glenohumeral joint is the most frequently dislocated articulation, but possibly due to the lower prevalence of posterior shoulder dislocations, approximately 50% to 79% of posterior glenohumeral dislocations are missed at initial presentation. The aim of this study was to systematically evaluate the most recent evidence involving the aetiology of posterior glenohumeral dislocations, as well as the diagnosis and treatment. A systematic search was conducted using PubMed (MEDLINE), Web of Science, Embase, and Cochrane (January 1997 to September 2017), with references from articles also evaluated. Studies reporting patients who experienced an acute posterior glenohumeral joint subluxation and/or dislocation, as well as the aetiology of posterior glenohumeral dislocations, were included. A total of 54 studies met the inclusion criteria. In total, 182 patients were included in this analysis; study sizes ranged from one to 66 patients, with a mean age of 44.2 years (sd 13.7). There was a higher proportion of male patients. In all, 216 shoulders were included with 148 unilateral injuries and 34 bilateral. Seizures were implicated in 38% of patients (n = 69), with falls, road traffic accidents, electric shock, and iatrogenic reasons also described. Time to diagnosis varied across studies from immediate up to a delay of 25 years. Multiple associated injuries are described. This review provides an up-to-date insight into the aetiology of posterior shoulder dislocations. Our results showed that seizures were most commonly implicated. Overall, reduction was achieved via open means in the majority of shoulders. We also found that delayed diagnosis is common.

The Veil of Obscuration: Additional Radiographic Sign of Posterior Shoulder Dislocation.

To describe a new radiographic sign, "veil of obscuration", associated with posterior glenohumeral joint (shoulder) dislocations and determine its incidence and validity compared to other known classic radiographic signs. Four-year retrospective study identified 30 acute posterior shoulder dislocation patients. Radiographs reviewed in consensus by 2 musculoskeletal radiologists for the "veil of obscuration", seen on AP shoulder radiographs and representing a comminuted fracture of the lesser tuberosity projecting over the humeral head or glenohumeral joint. Incidence of this radiographic sign of posterior glenohumeral joint dislocation in addition to other previously described classic radiographic signs, and association with other fractures, surgery, and mechanism of injury were evaluated. Continuous data was analyzed with student t-test and categorical data with Chi-Square test. There were 20 right and 10 left posterior shoulder dislocations. Majority of injuries resulted from vehicle crash (44%). In most cases, reverse Hill-Sachs lesion (83%) and fixed internal rotation of the humeral head (76%) were present, followed by trough line (43%) and "veil of obscuration" (40%). Trough line was seen in significantly more major trauma and vehicle crashes (78% and 46%; P=0.015), while "veil of obscuration" was seen in more seizures (86%; P=0.037) and in all surgical patients. No significant difference in presence of other classic radiographic signs in regards to surgery. The newly described radiographic sign of posterior shoulder dislocations named the "veil of obscuration" has comparable incidence as other classic radiographic signs and may be useful in the recognition and diagnosis of these injuries.

The influence of posterior glenohumeral joint capsule tightness and humeral retroversion on clinical measurements

ObjectivesTo assess the influence of posterior capsule tightness and humeral retroversion on shoulder motion measurements. DesignCross-Sectional study. SettingControlled university laboratory. Participants75 asymptomatic individuals were assigned to one of 4 groups: control (n = 28); posterior capsule tightness only (n = 17); humeral retroversion only (n = 15); and combined posterior capsule tightness and retroversion (n = 15). Main outcome measuresSix clinical measurements were compared across groups: bicipital forearm angle, low flexion, glenohumeral internal and external rotation, horizontal adduction and extension with internal rotation. ResultsThe group with both adaptations had decreased internal rotation compared to the control and retroversion only groups, as well as increased external rotation compared to the control and posterior capsule only groups. There were no between group differences for the horizontal adduction or extension with internal rotation measurements. The retroversion only and combined groups showed decreased bicipital forearm angle compared with the control and posterior tightness groups. The posterior capsule tightness and combined groups demonstrated decreased low flexion compared to the other groups. ConclusionThe combination of osseous and soft tissue adaptions alter shoulder motion measures more than a single adaption, making a comprehensive clinical assessment vital when managing individuals with shoulder pain.

Surgical and Rehabilitative Treatment of Misdiagnosed Posterior Dislocation of the Shoulder: Case Series

Background: Posterior gleno-humeral joint (GHJ) dislocation is a rare injury accounting for 2.7–3% of all shoulder dislocations. Early detection is the key for an effective treatment. Poor clinical outcomes or prosthetic solutions depend on the severity of the lesions at the time of trauma and worsening of the McLaughlin lesion during the months when the dislocation remains unrecognized or untreated. The aim of the study is to report our experience in treating, and clinically and radiographically evaluate the outcomes of, four neglected posterior GHJ dislocations. Methods: Four patients with inveterate posterior dislocation of the shoulder were evaluated. In three cases, the technique of McLaughlin was performed, and in one case, plication of the subscapularis tendon was performed. During the follow up, patients were clinically evaluated using the Constant shoulder score; an imaging investigation, using X-ray integrated with computed tomography(CT) and magnetic resonance imaging (MRI), was assessed. Results: Following the Constant criteria, treated shoulders reported an excellent outcome with an average score of 91. The mean score of untreated shoulders was 92.5. The humeral appearance that resulted was radiographically well-structured. Surgical treatment with McLaughlin lesion or transposition of the subscapularis were satisfactory from a subjective and objective point of view. To perform surgery soon as possible after the traumatic episode is considered a positive prognostic factor.

Posterior Shoulder Tightness: To Treat or Not to Treat?

Shoulder pain is a common musculoskeletal complaint that is difficult to treat because of the biomechanical complexity of the shoulder region, the interplay between mobility and stability, and the vital role played by the shoulder in moving, positioning, and providing stability for hand function. Despite advances in biomechanics and pain science, there is still much to learn about how impairments influence shoulder function and health. One impairment, posterior shoulder tightness (PST), is often noted in individuals with shoulder pain and consequently has generated much discussion and debate in recent years. Range-of-motion shifts and deficits are the clinical indicators of PST, with 3 tissue alterations potentially contributing to these modifications: (1) increased humeral retrotorsion (retroversion), (2) reduced posterior glenohumeral joint capsule extensibility, and (3) reduced posterior shoulder muscle/tendon extensibility. The significance of each alteration for shoulder function and the interaction among them remain unclear. It is also unknown if, or to what extent, these impairments can be resolved through interventions. This raises a clinically relevant and straightforward question: when PST is present, should we treat or not treat? In this Viewpoint, we will debate this question and propose that physical therapy interventions have the potential to improve only 1 of the 3 tissue alterations contributing to PST. J Orthop Sports Phys Ther 2018;48(3):133-136. doi:10.2519/jospt.2018.0605.

Epidemiology of Posterior Glenohumeral Instability in a Young Athletic Population

Background: While several studies have observed the incidence of posterior glenohumeral instability in selected populations, there are no data from large-scale population-based studies with corresponding athletic exposure data to calculate incidence rates (IRs) and associated risk factors. Purpose: To determine risk factors for posterior glenohumeral instability within the physically active population at the United States Military Academy. Study Design: Descriptive epidemiology study. Methods: A longitudinal cohort study was performed over a 6-year period from 2006 to 2012 at the United States Military Academy utilizing the Cadet Illness and Injury Tracking System. Exposure data were collected from daily attendance data documented for every practice and game at the intramural, club, or varsity sport level. The primary outcomes calculated were the IRs of posterior glenohumeral joint instability per 1000 person-years at risk and per 1000 athlete-exposures. IR ratios and confidence intervals were calculated between male and female cadets and between intercollegiate and intramural athletes. Results: Between 2006 and 2012, there were 1348 shoulder injuries in total, with 633 instability events. During the study period, 113 posterior shoulder instability injuries (17.9% of instability events) and 26,408 person-years at risk were documented, for an overall IR of 4.28 per 1000 person-years. The overall IR of posterior instability was 0.08 per 1000 athlete exposures. In male athletes, 105 sustained a posterior shoulder instability event, for an IR of 4.67 per 1000 person-years. Female athletes were less likely to sustain a posterior instability event, accounting for only 8 events, for an IR of 2.04 per 1000 person-years. A total of 6670 athletes were at risk for posterior shoulder instability injury during the study period. A total of 55 injuries were documented, for an IR of 8.25 per 1000 person-years. Intercollegiate wrestlers had the highest IR: 34.15 per 1000 person-years. The sport with the highest injury rate among intramural sports was football, at 2.79 per 1000 person-years. Three athletes had a history of a posterior shoulder dislocation, while no significant difference was found for subluxation versus pain as the presenting symptom. Of the 113 posterior shoulder instability injuries, 77.0% required surgical stabilization. All injuries associated with weight lifting required surgical stabilization. Conclusion: Among athletes, intercollegiate athletes are at an increased risk of posterior glenohumeral instability when compared with intramural athletes. Intercollegiate athletes and weight lifters demonstrate a high likelihood of requiring surgical treatment as compared with intramural athletes.

Concomitant Reverse Hill-Sachs Lesion and Posterior Humeral Avulsion of the Glenohumeral Ligament: Treatment With Fresh Talus Osteochondral Allograft and Arthroscopic Posterior Humeral Avulsion of the Glenohumeral Ligament and Labrum Repair

Chronic posterior glenohumeral joint instability can be a challenging clinical entity for patients and surgeons alike. In the setting of a posterior dislocation, a large anterior humeral impaction injury (reverse Hill-Sachs [HS]) may occur, leading to engagement of the humerus with the posterior glenoid bone, especially during internal rotation of the joint. A reverse HS is especially debilitating because of the significant portion of affected humeral head cartilage, and is made worse in the setting of ligamentous disruption such as a posterior humeral avulsion of the glenohumeral ligament (HAGL) lesions. Although several nonanatomic procedures to address these defects have been previously described, recent interest in anatomic reconstructions capable of restoring the cartilage surface of the humeral head has led to the use of bone grafts (autografts and allografts) to restore the articular contour of the humeral head in conjunction with anatomic repair of associated soft tissue injuries. We present our preferred technique for an anatomic repair of a posterior HAGL lesion in combination with reconstruction of an engaging reverse HS lesion using an unmatched hemitalar allograft.

Measurement of glenohumeral joint translation using real-time ultrasound imaging: A physiotherapist and sonographer intra-rater and inter-rater reliability study

BackgroundUltrasonography is an economical and non-invasive method for measuring real-time joint movements. Although physiotherapists are increasingly using ultrasound imaging for rotator cuff disorders, there is a lack of evidence on their reliability in using ultrasonography to measure glenohumeral translation. ObjectiveThe aim of this study was to evaluate the reliability of a physiotherapist in measuring anterior and posterior glenohumeral joint translation with ultrasound. MethodsStudy design: within day reliability.Anterior and posterior glenohumeral translations were measured at rest, in response to passive accessory motion testing force, and with isometric internal and external rotation in 12 young healthy adults. All the measurements were made in real time by a physiotherapist and an experienced sonographer in two positions (neutral and abducted) and in two views (anterior and posterior). Intra-rater and inter-rater reliability were expressed using intraclass correlation coefficients (ICC) and measurement error (mm). ResultsIntra-rater reliability was good for both raters (ICCP: 0.86–0.98; ICCS: 0.85–0.96). The inter-rater reliability between the physiotherapist and sonographer was moderate to good for posterior measurements (ICC 0.50–0.75) and poor to moderate for anterior measurements (ICC 0.31–0.53). For both intra-rater and inter-rater measurements, posterior translation was more reliable than the anterior translation with smaller measurement errors (posterior: 0.1–0.2 mm, anterior: 0.2–0.3 mm). ConclusionA physiotherapist with minimal training was reliable in measuring glenohumeral joint translations. The ultrasound method was reliable for repeated measurement of both anterior and posterior glenohumeral translations with posterior measurements being more reliable than anterior. This method is recommended for future research to investigate the stabilising role of rotator cuff muscles.