Editorial Commentary: Patients May Have Posterior Glenoid Labral Tears in the Absence of Instability or Magnetic Resonance Imaging Findings.

Posterior labral tears occur more often than imagined 25 years ago. Although such tears are generally identified in patients with posterior shoulder instability, the spectrum of labral tears in patients without instability creates a challenging diagnosis. Both physical examination and magnetic resonance imaging interpretation are difficult. Pathology encompassing posterior labral tears without instability notably reveals differences compared with throwers with posterior labral tears and patients with posterior instability. Recent research has identified 3 tear types: occult (type 1), incomplete (type 2), and complete (type 3). Attention to diagnosis deserves critical attention, in addition to tailoring of repair techniques to address the appropriate conditions in the shoulder. Even in patients without posterior instability and with ambiguous magnetic resonance imaging or magnetic resonance arthrography findings, posterior shoulder pain during daily activities or sports may indicate a posterior labral tear. Arthroscopic posterior labral repair without capsular plication provides good clinical outcomes and high rates of return to sport and labral healing.

Acute Shoulder Injuries in Adults.

Acute shoulder pain lasting less than six months is a common presentation to the primary care office. Shoulder injuries can involve any of the four shoulder joints, rotator cuff, neurovascular structures, clavicle or humerus fractures, and contiguous anatomy. Most acute shoulder injuries are the result of a fall or direct trauma in contact and collision sports. The most common shoulder pathologies seen in primary care are acromioclavicular and glenohumeral joint disease and rotator cuff injury. It is important to conduct a comprehensive history and physical examination to identify the mechanism of injury, localize the injury, and determine if surgical intervention is needed. Most patients with acute shoulder injuries can be treated conservatively using a sling for comfort and participating in a targeted musculoskeletal rehabilitation program. Surgery may be considered for treating middle third clavicle fractures and type III acromioclavicular sprains in active individuals, first-time glenohumeral dislocation in young athletes, and those with full-thickness rotator cuff tears. Surgery is indicated for types IV, V, and VI acromioclavicular joint injuries or displaced or unstable proximal humerus fractures. Urgent surgical referral is indicated for posterior sternoclavicular dislocations.

Chronic stage magnetic resonance imaging findings in patients with shoulder injury related to vaccine administration (SIRVA).

PURPOSE: Identify chronic shoulder MRI findings in patients with known shoulder injury related to vaccine administration (SIRVA). MATERIALS AND METHODS: Two fellowship-trained musculoskeletal radiologists retrospectively reviewed the MRI of nine patients with clinically established SIRVA. MRI was performed at least 4 weeks after vaccination and included intravenous contrast-enhanced sequences. MRI was reviewed for the presence of erosions, tendonitis, capsulitis, synovitis, bone marrow oedema, joint effusion, bursitis, cartilage defects, rotator cuff lesions, and lymphadenopathy. The number and location of focal lesions were recorded. RESULTS: Erosions of the greater tuberosity were present in 8/9 (89%), tendonitis of the infraspinatus muscle tendon in 7/9 (78%), capsulitis, synovitis, and bone marrow oedema in 5/9 (56%) cases, respectively. Effusion was found in three, and subdeltoid bursitis, rotator cuff lesions as well as cartilage defects in one patient, respectively. None of our included subjects showed axillary lymphadenopathy. CONCLUSION: In this case series, greater humeral tuberosity erosions, infraspinatus muscle tendonitis, capsulitis, synovitis, and bone marrow oedema were common MRI findings in chronic SIRVA.

Superior and Anterior Glenoid Labral Tears Are Associated With Increased Neurofilament Concentration.

BACKGROUND: Pain is a common presentation after glenohumeral labral injuries. However, the source of that pain is undetermined. PURPOSE/HYPOTHESIS: We aimed to determine if there is a differential expression of nerve fibers around the glenoid labrum and if torn labra have increased neuronal expression compared with untorn labra (rotator cuff repair labra). We hypothesized that the superior labrum would have a higher concentration of neurofilament than would the rest of the labrum and that the concentration of neurofilament would increase at the site of a labral tear. STUDY DESIGN: Descriptive laboratory study. METHODS: Seven labra were sampled at the 3-, 5-, 9-, and 12-o'clock positions during total shoulder arthroplasty. Samples were also collected at the 3-, 5-, and 12-o'clock positions during rotator cuff repair (16 labra), anterior labral repair (6 labra), type II superior labral anterior to posterior (SLAP) repair (4 labra), and capsular release for idiopathic capsulitis (5 labra). Sections were immunostained with antibodies to neurofilament, a specific neuronal marker that is used to identify central and peripheral nerve fibers, and the concentration and intensity of immunostained-positive cells assessed. RESULTS: The concentration of neurofilament staining was similar in the superior, anterior, posterior, and inferior glenoid labrum in untorn labra (8 neurofilament expressing cells per square millimeter; P = .3). Torn labra exhibited a 3- to 4-fold increase in neuronal expression, which was isolated to the location of the tear in SLAP (P = .09) and anterior labral tears (P = .02). The concentration of neurofilament expressing cells in torn glenoid labrum samples was comparable that in with the glenoid labrum of adhesive capsulitis samples (P = .7). CONCLUSION: This study supports the hypothesis that after a tear of the anterior or superior labrum the labrum in that region becomes populated with new nerves fibers and that these fibers may be responsible for the pain noted by patients with superior (SLAP) and/or anterior labral (Bankart) tears. CLINICAL RELEVANCE: This study suggests that neural infiltration contributes to the pain experienced by patients with labral tears. It may help with patient education and direct future management of labral lesions.

Calcific tendinitis of the shoulder induced by an mRNA vaccine for COVID-19: A case report.

Coronavirus disease 2019 (COVID-19) vaccines have been widely used and have been shown to be effective in combating the pandemic. However, various side effects have been reported following vaccination. For instance, a condition called 'shoulder injury related to vaccine administration' (SIRVA) is characterized by shoulder pain and limited range of motion after intramuscular injection of a vaccine into the deltoid muscle of the shoulder. Despite an increase in SIRVA cases, the exact incidence of the disease is unclear, and there are a few reports of SIRVA about the COVID-19 vaccine. Here, we report a rare case of an 83-year-old woman who was diagnosed with calcification in her left shoulder 1 year ago and developed calcific tendinitis after receiving an mRNA vaccine for COVID-19 (Pfizer-BioNTech). Radiographs showed calcification of the supraspinatus tendon, and magnetic resonance images showed continuous inflammatory findings from the subdeltoid bursa to the subacromial bursa. We treated the patient with celecoxib and acetaminophen, and she recovered after about 2 months. In order to prevent SIRVA, the presence of shoulder joint disease should be carefully asked during a pre-vaccination assessment. The puncture point should be chosen with the median point of the deltoid muscle or the anterior-posterior axillary line as landmarks because the more cephalad the puncture position, the greater the chance of causing SIRVA.

Accuracy of MR arthrography in the detection of posterior glenoid labral injuries of the shoulder.

OBJECTIVE: The purpose of this study is to evaluate the accuracy of MR arthrography in detecting isolated posterior glenoid labral injuries using arthroscopy as the reference standard. METHODS: MR arthrograms of 97 patients with isolated posterior glenoid labral tears by arthroscopy and those of 96 age and gender-matched controls with intact posterior labra were reviewed by two blinded radiologists for the presence and location of posterior labral abnormalities. The sensitivity and specificity of detection of posterior labral tears were calculated as well as the prevalence of associated pathologies. Medical records were reviewed for demographics, history and direction of shoulder instability, and prior surgery. RESULTS: Posterior labral pathology was detected by MR arthrography with sensitivities of 76% and 84% for readers 1 and 2, and a specificity of 88% for both readers. Kappa value for interreader agreement was 0.91. Twenty-two of twenty-three (96%) tears isolated to the posteroinferior quadrant on arthroscopy were correctly identified on MRI. Commonly associated pathologies included paralabral cyst (38%), humeral fracture (7%), and glenoid fracture (2%). Fifteen of ninety-seven (16%) patients with posterior tears on both arthroscopy and MRI had glenoid rim deficiency on imaging versus no patients with intact posterior labra (p < 0.001). Forty of ninety-seven (41%) patients with posterior tears on arthroscopy had a history of posterior instability versus none without posterior tears. There was no significant difference in tear length on MRI between those with a history of instability and those without (p = 0.56). CONCLUSION: MR arthrography is accurate in detecting posterior glenoid labroligamentous injuries.

Relationships between the seated single arm shot put test and Quick-DASH in patients being discharged from physical therapy.

BACKGROUND: Research examining the relationship between patient reported outcomes (PRO) and upper extremity functional performance tests (UEFPT) in patients with shoulder pathology are limited. OBJECTIVE: To assess the relationship between the seated single arm shot put test (SSASPT) and the PRO Quick-Disabilities of Arm, Shoulder, and Hand (DASH) in patients being discharged from physical therapy after shoulder injury or surgery. METHODS: Six physical therapists who regularly use the SSASPT and DASH from six different clinical sites provided SSASPT scores and completed Quick-DASH forms on 75 patients being discharged from rehabilitation following shoulder injury or surgery. Patients were grouped according to whether the involved shoulder was the dominant (n = 43) or nondominant (n = 32) limb. Three separate simple linear regression models, whole cohort and two patient groups, were created to determine the magnitude of the relationships (standardized betas) and change (betas) between DASH scores and the SSASPT limb symmetry index (LSI). RESULTS: Neither whole cohort nor two groups exhibited statistically significant (P > .05) relationships between LSI and Quick-DASH scores based upon the standardized betas (-0.197-0.038). Additionally, neither the standardized betas (z = 1.49, P = .135) nor betas (z = 1.28, P = .200) were statistically different between the two groups. CONCLUSIONS: The current study revealed no association between SSASPT and the Quick-DASH at discharge from physical therapy following shoulder injury or surgery. Consequently, it may be important to perform a battery of tests that include both subjective PRO and objective UEFPT tests to obtain a comprehensive perspective of the patient's functional and perceived status.

MR arthrography: correlation between anatomic intraarticular variants of the long head of the biceps tendon (long head biceps tendon) and superior labral anterior to posterior (SLAP) lesions.

BACKGROUND: The purpose of this work is to characterize the anatomy of the intraarticular portion of the long head of the biceps tendon (long head biceps tendon) using magnetic resonance (MR) arthrography by investigating whether anatomical variants may facilitate the onset of a supraequatorial lesion (superior labral anterior to posterior, SLAP). MATERIALS AND METHODS: In 482 shoulder MR arthrographies, we considered the anatomical variants of the intraarticular portion of the long head of the biceps tendon classified according to Dierickx's arthroscopic classification; lesions of supraequatorial structures were considered in the data analysis. For each anatomical variant, correlation with SLAP and the odd ratio were statistically evaluated, using Fisher's exact (or chi-squared) test and logistic regression analysis, respectively. RESULTS: In the mesotenon-type variant, the SLAP frequency was higher than expected [χ2 (df = 4) = 14.9, p = 0.005] with a higher risk of developing a type I SLAP (p = 0.0003). In the adherent-type variant, the type II SLAP frequency was higher than expected [χ2 (df = 3) = 18.1, p = 0.0004] with a higher risk of developing type II SLAP (p = 0.0001). Two cases of "split" (SPL) long head biceps tendon had III and type IV SLAP, respectively. These patients have a higher risk for type IV SLAP [odds ratio (OR) 19.562, 95% confidence interval (CI) 1.604-238.541, p = 0.001]. An increased risk of developing SLAP type II was calculated for male subjects (OR 3.479, 95% CI 1.013-11.951, p = 0.019). CONCLUSIONS: It is possible that adherence of the long head biceps tendon to the supraspinatus more often predisposes to a lesion of the superior glenoid labrum (SLAP), in view of the close relationships between the fibrocartilage and the bicipital anchor, probably related to the limited excursion of the intraarticular long head biceps tendon.

Humeral Avulsion of the Glenohumeral Ligament: Diagnosis and Management.

¼: The most common type of humeral avulsion of the glenohumeral ligament (HAGL) is a purely ligamentous avulsion involving the anterior inferior glenohumeral ligament (IGHL), but other variants are seen, including posterior lesions and those with an osseous avulsion. ¼: A central lesion between the intact anterior and posterior bands of the IGHL is gaining recognition as a distinct clinical entity. ¼: HAGL lesions are most commonly seen in patients with anterior instability without a Bankart tear or in those with persistent symptoms despite having undergone a Bankart repair. ¼: Magnetic resonance imaging is the most sensitive imaging modality. An arthrogram is helpful with subacute and chronic lesions when the joint is not distended. Arthroscopy is the gold standard for diagnosis. ¼: While some have reported success with nonoperative management, surgical repair with either arthroscopic or open techniques has provided a high rate of successful outcomes; however, the literature is limited to mostly Level-IV and V evidence.

An analysis of pre-season risk factors for low back injury in high-school baseball pitchers: a prospective study.

Pitching motion requires whole-body coordination; therefore, poor control of the lower extremities, pelvis and trunk may cause shoulder and elbow injuries. However, few studies have described the relationship between the shoulder joint function and low back injury in high-school baseball pitchers. A total of 128 healthy high school pitchers underwent pre-season medical checkups, where their shoulder range of motion and shoulder strength were measured. The participants completed a self-recorded daily questionnaire regarding the presence of low back pain. Pitchers were divided into injured and non-injured groups. Low back injury was observed in 13 participants (13.4%). In the injured group, horizontal adduction on the dominant shoulder was significantly less than in the non-injured group. A logistic regression analysis showed that horizontal adduction on the dominant side was a significant independent risk factor for low back injury during the season. It is important to recognize that restriction of the shoulder function not only causes shoulder and elbow injuries but can also risk low back injury.

Career Longevity and Performance After Shoulder Instability in National Football League Athletes.

PURPOSE: To investigate the career longevity, game utilization, and performance of National Football League (NFL) athletes after glenohumeral instability events treated operatively versus nonoperatively. METHODS: Using public resources, we identified NFL players who sustained a shoulder instability event from September 2000 to February 2019. Players with prior shoulder instability, without NFL experience before injury, or who did not return to play (RTP) after injury were excluded. Demographic information, utilization (games and seasons), and season approximate value (SAV) statistics were recorded 1 year prior to injury and 3 years after RTP. Statistical analysis compared utilization and the SAV after RTP for athletes managed operatively versus nonoperatively. RESULTS: We identified 97 NFL players who sustained their first instability event while playing in the NFL, 91 of whom returned to play (93.8%). Quarterbacks were significantly more likely to undergo immediate surgical management compared with players in other positions (P = .023). The final analysis included 58 players managed operatively and 33 managed nonoperatively by the end of the index season. Players treated operatively played in significantly more seasons after RTP during their remaining careers (4.1 ± 2.7 seasons vs 2.8 ± 2.5 seasons, P = .015). There were no differences in games played or started, offensive or defensive snap count percentage, or performance (SAV) before and after injury when compared between cohorts (P > .05). After surgical stabilization, time to RTP (36.62 ± 10.32 weeks vs 5.43 ± 12.33 weeks, P < .05) and time interval before recurrent instability (105.7 ± 100.1 weeks vs 24.7 ± 40.6 weeks, P < .001) were significantly longer than with nonoperative treatment. Additionally, the operative cohort experienced less recurrent instability (27% vs 50%, P = .035). CONCLUSIONS: Athletes who RTP in the NFL after a shoulder instability injury do so with a similar workload and performance irrespective of surgical or nonsurgical management. Whereas nonoperative treatment is associated with faster RTP, operative management is associated with fewer recurrent instability events, greater time between recurrent instability events, and greater career longevity. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

National Trends in the Repair of Isolated Superior Labral Tear from Anterior to Posterior in Korea.

BACKGROUND: The optimal treatment for superior labral tear from anterior to posterior (SLAP) lesions is controversial. Thus, we aimed to investigate the national surgical trends in isolated SLAP repair in Korea. METHODS: We analyzed a nationwide database from the Korean Health Insurance Review and Assessment Service from 2008 to 2017. We investigated the trends in SLAP repair by time, sex, age, and the type of health care institution. RESULTS: From 2008 to 2017, 27,850 isolated SLAP repairs were identified. Age-adjusted incidence rate of isolated SLAP repair increased by 692% from 1.07/100,000 in 2008 to 8.48/100,000 in 2012 (P = 0.005). However, the incidence rate declined significantly after 2012 (P = 0.032) and was 5.28/100,000 in 2017. Sex-specific incidence rate of isolated SLAP repair was 2.3 times higher in men than in women. The decline since 2012 was most evident in patients aged ≥ 40 years (P = 0.01); however, the incidence rates of isolated SLAP repair during the study period were similar between patients aged ≥ 40 years and those aged < 40 years. Moreover, hospitals with 30-100 beds had the greatest change in the number of isolated SLAP repair cases. CONCLUSION: In Korea, the incidence of isolated SLAP repair increased dramatically until 2012; since then, it has declined. Although the decrease in isolated SLAP repair later in the study was evident in those aged ≥ 40 years, the incidence rate was still relatively high in patients aged ≥ 40 years.

Humeral Retroversion and Injury Risk After Proximal Humeral Epiphysiolysis (Little Leaguer's Shoulder).

BACKGROUND: The increased humeral retroversion on the dominant side of throwing athletes is thought to result from repetitive throwing motion. Little Leaguer's shoulder-a rotational stress fracture of the proximal humeral epiphyseal plate-may influence the risk of humeral retroversion and injury of the shoulder or elbow joint. PURPOSE: To investigate the effect of Little Leaguer's shoulder on humeral retroversion and the rates of shoulder and elbow injuries. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: 10 high school baseball players (average age, 16.6 years; range, 16-18 years) who had experienced Little Leaguer's shoulder during elementary or junior high school (average age, 12.6 years; range, 11-15 years) were enrolled in the study. As a control group, 22 high school baseball players (average age, 16.9 years; range, 16-18 years) who had never had any shoulder or elbow injury during elementary and junior high school were included. Humeral retroversion on ultrasonographic measurement, shoulder range of motion, and rates of shoulder and elbow injuries were evaluated. RESULTS: Humeral retroversion was significantly greater on the dominant side than on the nondominant side in both players with Little Leaguer's shoulder (dominant, 104°± 8°; nondominant, 84°± 12°; P < .001) and controls (dominant, 91°± 13°; nondominant, 81°± 10°; P < .001). In the dominant shoulder, humeral retroversion was greater in the Little Leaguer's shoulder group than in the control group (P = .008). When the effects of humeral retroversion were excluded, maximal external rotation was significantly less in the dominant shoulder than in the nondominant shoulder in the Little Leaguer's shoulder group (by 11°± 12°, P = .02), whereas no significant difference was found between dominant (110°± 11°) and nondominant (111°± 13°) shoulders in the control group (P = .64). The rates of shoulder and elbow pain were significantly higher in the Little Leaguer's shoulder group (shoulder pain 80%, elbow pain 70%) than in the control group (shoulder pain 9%, P < .001; elbow pain 32%, P = .04). CONCLUSION: Humeral retroversion was increased in baseball players without any history of shoulder or elbow injury during elementary and junior high school and was further increased in players who had had Little Leaguer's shoulder. Increased humeral retroversion after Little Leaguer's shoulder may be a risk factor for future shoulder or elbow injury.

Proresolving Mediators LXB4 and RvE1 Regulate Inflammation in Stromal Cells from Patients with Shoulder Tendon Tears.

Tendon stromal cells isolated from patients with chronic shoulder rotator cuff tendon tears have dysregulated resolution responses. Current therapies do not address the biological processes concerned with persistent tendon inflammation; therefore, new therapeutic approaches that target tendon stromal cells are required. We examined whether two specialized proresolving mediators (SPMs), lipoxin B4 (LXB4) and resolvin E1 (RvE1), modulate the bioactive lipid mediator profiles of IL-1ß-stimulated tendon cells derived from patients with shoulder tendon tears and healthy volunteers. We also examined whether LXB4 or RvE1 treatments moderated the proinflammatory phenotype of tendon tear stromal cells. Incubation of IL-1ß-treated patient-derived tendon cells in LXB4 or RvE1 up-regulated concentrations of SPMs. RvE1 treatment of diseased tendon stromal cells increased 15-epi-LXB4 and regulated postaglandin F2α. LXB4 or RvE1 also induced expression of the SPM biosynthetic enzymes 12-lipoxygenase and 15-lipoxygenase. RvE1 treatment up-regulated the proresolving receptor human resolvin E1 compared with vehicle-treated cells. Incubation in LXB4 or RvE1 moderated the proinflammatory phenotype of patient-derived tendon tear cells, regulating markers of tendon inflammation, including podoplanin, CD90, phosphorylated signal transducer and activator of transcription 1, and IL-6. LXB4 and RvE1 counterregulate inflammatory processes in tendon stromal cells, supporting the role of these molecules as potential therapeutics to resolve tendon inflammation.

Bennett lesions in overhead athletes and associated shoulder abnormalities on MRI.

OBJECTIVE: To determine if a Bennett lesion and its size are associated with additional MRI shoulder abnormalities in an overhead athlete. MATERIALS AND METHODS: An IRB-approved retrospective review of our database from 1 January 2012 to 1 April 2018 identified 35 overhead athletes with a Bennett lesion on MRI. A control group consisting of 35 overhead athletes without a Bennett lesion were matched for age, level of play (professional vs non-professional), and type of study (arthrogram vs non-arthrogram). Each study was assessed independently by two MSK fellowship trained radiologists. The sizes of the Bennett lesions were measured. Each MRI was assessed for the presence of a labral tear, posterior glenoid cartilage abnormality, humeral head notching or cysts, and fraying or tear of the supraspinatus or infraspinatus tendons. Statistical analyses were performed using Student's t test, Fisher's exact test, and Chi-squared test. RESULTS: There was an increased incidence of posterior glenoid cartilage abnormalities in athletes with Bennett lesions vs those without (23% vs 3%, p value = 0.01). There was no difference in any other MRI abnormalities, including labral tears and findings of internal impingement between these two groups (p value range = 0.09-0.46). There was no association between the size of a Bennett lesion and the presence of glenoid cartilage lesions, labral tears, internal impingement, age, professional status, or need for surgery (p value range = 0.08-0.96). CONCLUSION: Symptomatic overhead athletes with Bennett lesions have an increased frequency of posterior glenoid cartilage abnormalities, but not labral tears or findings of internal impingement compared to those without Bennett lesions.

Radiologic and Histologic Evaluation of Proximal Bicep Pathology in Patients With Chronic Biceps Tendinopathy Undergoing Open Subpectoral Biceps Tenodesis.

PURPOSE: To correlate preoperative magnetic resonance imaging (MRI) and intraoperative anatomic findings within the proximal long head biceps tendon to histologic evaluation of 3 separate zones of the tendon in patients with chronic biceps tendinopathy. METHODS: Sixteen patients with chronic biceps tendinopathy were treated with open subpectoral biceps tenodesis. Preoperative MRI tendon grading was as follows: normal tendon, increased signal, tendon splitting, incomplete/complete tear. The removed portion of the biceps tendon was split into 3 segments: zone 1, 0-3.5 cm from the labral insertion; zone 2, 3.5-6.5 cm; and zone 3, 6.5-9 cm, and was histologically evaluated using the Bonar score. Tenosynovium adjacent to the tendon was assessed histologically using the Osteoarthritis Research Society International score. CD31, CD3, and CD79a immunohistochemistries were conducted to determine vascularization, T-cell infiltrates, and B-cell infiltrates, respectively. Analysis of variance and Pearson correlations were performed for statistical analysis. RESULTS: Preoperative MRI showed no significant differences in tendon appearance between zones 1-3. Intraoperative findings included nonspecific degenerative SLAP tears or mild/moderate biceps tenosynovitis in all cases. Significantly (P < .001) higher Bonar scores were noted for tendon in zones 1 (7.9 ± 1.8) and 2 (7.3 ± 1.5) compared with zone 3 (5.0 ± 1.1). Cell morphology scores in zone 1 (1.9 ± 0.4) and zone 2 (1.5 ± 0.6) were significantly higher than that in zone 3 (0.8 ± 0.3) (P < .05). Inflammatory tenosynovium showed weak correlation with tendon changes in zone 1 (r = 0.08), zone 2 (r = 0.03), or zone 3 (r = 0.1). CONCLUSIONS: In patients with chronic long head biceps tendinopathy who underwent open subpectoral tenodesis, MRI and intraoperative assessment did not show significant structural abnormalities within the tendon despite significant histopathologic changes. Severity of tendon histopathology was more pronounced in the proximal and mid-portions of the tendon. CLINICAL RELEVANCE: Proximal versus distal biceps tenodesis is a subject of frequent debate. This study contributes to the ongoing evaluation of the characteristics of the proximal biceps in this type of pathologic condition.

Understanding the Importance of the Teres Minor for Shoulder Function: Functional Anatomy and Pathology.

Although the teres minor is often overlooked in a normal shoulder, it becomes a key component in maintaining shoulder function when other rotator cuff tendons fail. The teres minor maintains a balanced glenohumeral joint and changes from an insignificant to the most significant external rotator in the presence of major rotator cuff pathology. The presence or absence of the teres minor provides prognostic information on the outcomes of reverse total shoulder arthroplasty and tendon transfers. Clinical tests include the Patte test, the Neer dropping sign, the external rotation lag sign, and the Hertel drop sign. Advanced imaging of the teres minor can be used for classification using the Walch system. Understanding the function and pathology surrounding the teres minor is paramount in comprehensive management of the patient with shoulder pathology. Appropriate clinical examination and imaging of the teres minor are important for preoperative stratification and postoperative expectations.

A prospective, observational cohort study of patients presenting to an emergency department with acute shoulder trauma: the Manchester emergency shoulder (MESH) project.

BACKGROUND: Fracture and dislocation of the shoulder are usually identifiable through the use of plain radiographs in an emergency department. However, other significant soft tissue injuries can be missed at initial presentation. This study used contrast enhanced magnetic resonance arthrography (MRA) to determine the pattern of underlying soft tissue injuries in patients with traumatic shoulder injury, loss of active range of motion, and normal plain radiography. METHODS: A prospective, observational cohort study. Twenty-six patients with acute shoulder trauma and no identifiable radiograph abnormality were screened for inclusion. Those unable to actively abduction their affected arm to 90° at initial presentation and at two week's clinical review were consented for MRA. RESULTS: Twenty patients (Mean age 44 years, 4 females) proceeded to MRA. One patient had no abnormality, three patients showed minimal pathology. Four patients had an isolated bony/labral injury. Eight patients had injuries isolated to the rotator cuff. Four patients had a combination of bony and rotator cuff injury. Four patients were referred to a specialist shoulder surgeon following MRA and underwent surgery. CONCLUSIONS: Significant soft tissue pathology was common in our cohort of patients with acute shoulder trauma, despite the reassurance of normal plain radiography. These patients were unable to actively abduct to 90° both at initial presentation and at two week's post injury review. A more aggressive management and diagnostic strategy may identify those in need of early operative intervention and provide robust rehabilitation programmes.