Coracohumeral Interval Imaging in Subcoracoid Impingement Syndrome on MRI

Higher Upper Subscapularis Goutallier Grade and Coracohumeral Distance Narrowing Are Predictive of Subscapularis Tears in Patients Undergoing Arthroscopic Rotator Cuff Repair

PURPOSE

To evaluate the relation between subscapularis (SSC) Goutallier grade or coracohumeral distance (CHD) and SSC tears, as well as the relation between these radiographic variables and long head of the biceps tendon lesions.

METHODS

A retrospective analysis was conducted on prospectively maintained data on patients who underwent arthroscopic rotator cuff repair of SSC tears between 2011 and 2021 with at least 6 months of follow-up. Patients with identified subscapularis tears during arthroscopy were included. A control group was established by randomly selecting patients without SSC tears from the same study period. Goutallier grading and CHD were obtained from preoperative magnetic resonance imaging (MRI) scans. Receiver operating characteristic analysis was conducted to define optimal cutoff values for these diagnostic measures.

RESULTS

The study included 735 patients with SSC tears and 249 patients in the control group. Comparing subscapularis tear and intact groups' Goutallier grades revealed significant differences in infraspinatus, upper and lower SSC, and overall SSC (P < .001). No significant difference was detected in supraspinatus Goutallier grade (P = .364). An SSC tear was observed in 58.3% (n = 265) of patients with Goutallier grade 0 of the upper SSC, 77.1% (n = 195) of patients with grade 1 changes, 98.7% (n = 155) with grade 2 changes, and 100% of grade 3 or 4 changes. Goutallier grade of the upper SSC showed a significant correlation with tear size (rs = 0.533; P < .01). CHD measurements were lower in individuals with SSC tears compared to those without tears (6.6 ± 1.7 vs 9.6 ± 1.8; P < .001). Upper SSC Goutallier grade >1 had an acceptable area under the curve (AUC) of 0.742. CHD of 7.96 mm or less had an excellent predictive AUC of 0.879.

CONCLUSIONS

Higher Goutallier grade and CHD narrowing are potential associations predictive of SSC tears. Routine MRI assessment of muscle of the upper SSC and the CHD can contribute to the diagnostic accuracy of SSC tears and offer valuable information regarding the severity of such tears.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Reliability of coracohumeral distance and subcoracoid tendons in subacromial pain syndrome

This study investigated the intra-rater reliability of a novice ultrasound (US) examiner and the inter-rater reliability of two examiners (novice, expert) in the measures of coracohumeral distance at rest (CHD) and at 60° of elevation without (CHD60) or with weights (CHD60w), tendon thickness of the long head of the biceps (LHB) and subscapularis (SCP). Twenty-one patients with subacromial pain syndrome (SAPS) and 20 asymptomatic participants were included. Intra and inter-rater reliability were tested with intraclass-correlation-coefficient (ICC), differences between raters were analyzed with Bland-Altman plots. Intra-rater reliability for CHD, CHD60 and CHD60w was excellent (ICC = 0.97-0.98) in asymptomatic participants, and good-to-excellent (0.88-0.93) in SAPS, while intra-rater reliability for LHB and SCP was good-to-excellent in asymptomatic participants (0.88-0.97) and in SAPS (0.90-0.92). Inter-rater reliability for CHD, CHD60 and CHD60w was moderate-to-good (0.70-0.90) in asymptomatic participants and good (0.85-0.87) in SAPS, in contrast inter-rater reliability for LHB and SCP was poor in asymptomatic participants (0.10-0.46) and poor-to-moderate (0.49-0.61) in SAPS. Bland-Altman plots revealed systematic and/or proportional bias for tendons' thickness. A novice showed good-to-excellent intra-rater reliability in all US measures, whereas in comparison to an expert a novice can measure reliably CHD, CHD60 and CHD60w, but not LHB and SCP, where more training is recommended.

Shoulder Impingement Syndrome

Shoulder impingement is the most common diagnosis for shoulder pain. Shoulder impingement syndrome has been scrutinized as a misleading "umbrella" term, due to its vague and nonspecific context. It is better subcategorized into subacromial, internal, and subcoracoid impingement. The evaluation and treatment algorithm for each is grossly similar. A thorough history, focused physical examination, and standard radiographs are the first steps. Advanced imaging with MRI or ultrasound may be useful. The mainstay of treatment includes physical therapy, anti-inflammatory medications, and injections. Surgical treatment is reserved for refractory cases, and includes decompression, debridement, and/or repair of injured structures.

Is it the subcoracoid impingement or the subacromial impingement that tears the subscapularis tendon? A comparison of the MRI findings of the operated and healthy shoulders of the patients

BACKGROUND

: The purpose of this study is to investigate whether the etiological factors accepted as causes of idiopathic subscapularis tears are true or not when the comparison is made with the opposite side healthy shoulder of the patients who underwent arthroscopic repair for an isolated subscapularis tear.

METHODS

Sixteen patients who underwent shoulder arthroscopy between February 2016 and January 2018 and were diagnosed with isolated subscapularis tear were evaluated. The coracohumeral distance (CHDax), coracoid overlap (CO), and tuberculum minus cysts (TMC) were evaluated on the axial images of the MRI studies while the acromiohumeral distance (AHDsag), CHDsag, and subscapularis tendon slip number (STSN) on the sagittal oblique images and the AHDcor and SLAP lesion on the coronal oblique images. Degeneration of the coracoacromial ligament was evaluated during arthroscopy.

RESULTS

The mean CHDsag (11.26-10.08), CHDax (10.63-9.98), CO (14.2-15.43), AHDsag (8-7.66), and AHDcor (7.65-7.68) measurements (operated side-healthy side, respectively) were statistically similar (p > 0.05). No statistically significant difference was found between TMC and STSN in healthy and operated shoulders (p > 0.05). There was mild coracoacromial ligament fraying in 4 (25%) and obvious coracoacromial ligament fraying in 8 (50%) which indicated subacromial impingement in 75% of the patients.

DISCUSSION

The parameters of the coracoid process did not reveal any significant difference between the operated (for an isolated subscapularis tear) and opposite-side healthy shoulders of the patients. However, coracoacromial ligament degeneration was present in 75% of the patients.

In Vivo Anatomical Research by 3D CT Reconstruction Determines Minimum Acromiohumeral, Coracohumeral, and Glenohumeral Distances in the Human Shoulder: Evaluation of Age and Sex Association in a Sample of the Chinese Population

Accurate measurement of the minimum distance between bony structures of the humeral head and the acromion or coracoid helps advance a better understanding of the shoulder anatomical features. Our goal was to precisely determine the minimum acromiohumeral distance (AHD), coracohumeral distance (CHD), and glenohumeral distance (GHD) in a sample of the Chinese population as an in vivo anatomical analysis. We retrospectively included 146 patients who underwent supine computed tomography (CT) examination of the shoulder joint. The minimum AHD, CHD, and GHD values were quantitatively measured using three-dimensional (3D) CT reconstruction techniques. The correlation between minimum AHD, CHD, and GHD value and age with different sexes was evaluated using Pearson Correlation Coefficient. The mean value of minimum AHD in males was greater than that in females (male 7.62 ± 0.98 mm versus female 7.27 ± 0.86 mm, p = 0.046). The CHD among different sexes differed significantly (male 10.75 ± 2.40 mm versus female 8.76 ± 1.38 mm, p < 0.001). However, we found no statistical differences in GHD with different sexes (male 2.00 ± 0.31 mm versus female 1.96 ± 0.36 mm, p > 0.05). In terms of age correlation, a negative curve correlation existed between age and AHD among the different sexes (male R2 = 0.124, p = 0.030, female R2 = 0.112, p = 0.005). A negative linear correlation was found in CHD among the different sexes (male R2 = 0.164, p < 0.001, female R2 = 0.122, p = 0.005). There were no differences between age and minimum GHD in both sexes. The 3D CT reconstruction model can accurately measure the minimum AHD, CHD, and GHD value in vivo and is worthy of further investigation for standard clinical anatomical assessment. Aging may correlate with AHD and CHD narrowing for both sexes.

Coracoid Impingement and Morphology Is Associated with Fatty Infiltration and Rotator Cuff Tears

This study describes measurements between the coracoid, glenoid, and humerus; characterizes coracoid shape, rotator cuff fatty infiltration, and quantitatively evaluates coracoid impingement and its association with anterosuperior rotator cuff tears (ASCT). 193 shoulder magnetic resonance imaging (MRI) scans demonstrating: rotator cuff tear; isolated tear of the supraspinatus; tear of supraspinatus and subscapularis, were included. MRI measurements included coracohumeral interval (CHI), coracoid overlap (CO), coracoid recess (CR), coracoglenoid angle (CGA), and coracoglenoid interval (CGI) on axial slices; acromiohumeral interval (AHI) on coronal slices; and coracohumeral interval (CHI) and coracoacromial ligament (CAL) thickness on sagittal slices. The coracoid shape was classified as flat, curved, or hooked. An Independent T-test was used to compare the MRI measurements and the different rotator cuff tear groups. In 79% of the patients with ASCT tears, the coracoid was curved. Axial CHI, CGA, sagittal CHI, and AHI were decreased in ASCT when compared to no tears and isolated supraspinatus tears (p < 0.05). CO was increased in ASCT compared to no tears and isolated supraspinatus tears (p < 0.05). Patients with an ASCT had a significantly increased subscapularis and supraspinatus Goutallier fatty infiltration score when compared to no tear and isolated supraspinatus tears (p < 0.05). These quantitative measurements may be useful in identifying patients at risk for ASCT. Level of Evidence III.

Imaging Review of Subscapularis Tendon and Rotator Interval Pathology

As the largest rotator cuff muscle, the subscapularis plays a major role in stabilizing the glenohumeral joint, in conjunction with surrounding rotator cuff structures. Injury to the subscapularis tendon can be isolated, but more commonly is seen in conjunction with supraspinatus tendon pathology. Injury can be associated with biceps pulley instability, superior labral anterior-posterior (SLAP) tears, humeral head subluxation, and anterosuperior and coracoid impingements. The involvement of the rotator interval can lead to what is called “the hidden lesion,” due to its difficulty to diagnose during arthroscopy. Understanding the anatomical relations of the subscapularis tendon with the rest of the rotator cuff and rotator interval, as well as common patterns of injury that involve the subscapularis tendon, can aid in proper diagnosis of these injuries leading to prompt surgical repair. This review describes the anatomy of the subscapularis muscle and tendon, and the magnetic resonance imaging (MRI) patterns of subscapularis tendon injury.

Is shoulder geometry important for rotator cuff tears?

PURPOSE

This study is aiming to evaluate some specific anatomic shoulder parameters such as the lateral acromial angle (LAA), acromial index (AI), coracohumeral distance (CHD) and critical shoulder angle (CSA) in rotator cuff tears.

METHODS

A total of 100 cases consisting of 50 patients with rotator cuff tears and 50 patients without rotator cuff tears, who underwent shoulder MRI (mangnetic resonance imaging) examination in Istanbul Medipol University Orthopedics and Traumatology Department, participated in this study. In this retrospective study, CCA, LAA, AI and CSA were evaluated in MRI in order to shed light on the theories of rotator cuff tears.

RESULTS

There was no significant difference (P ˃ .05) in acromial index and coracohumeral distance in the patient group. Lateral acromial angle and critical shoulder angle were significantly different in the patient group compared to the control group (P < .05). There was a weak negative correlation between CSA and CHD.

CONCLUSION

In our study, we found that patients with smaller LAA and higher CSA values in MRI images are prone to have rotator cuff tears. Further studies are needed in order to evaluate whether this association has predictive value.

Less than 9.5-mm coracohumeral distance on axial magnetic resonance imaging scans predicts for subscapularis tear

Background

Diagnosis of subscapularis (SSC) tendon lesions on magnetic resonance imaging (MRI) can be challenging. A small coracohumeral distance (CHD) has been associated with SSC tears. This study was designed to define a specific threshold value for CHD to predict SSC tears on axial MRI scans.

Methods

This retrospective study included 172 shoulders of 168 patients who underwent arthroscopic surgery for rotator cuff tear or glenohumeral instability. Diagnostic arthroscopy confirmed an SSC tear in 62 cases (36.0%, test group a), rotator cuff tear tears other than SSC in 71 cases (41.3%, control group b) and glenohumeral instability without any rotator cuff tear in 39 cases (22.7%, zero-sample group c). All patients had a preoperative MRI of the shoulder (1.5T or 3T). Minimum CHD was measured on axial fat-suppressed proton density-, T2-, or T1-weigthed sequences. Receiver operating characteristics analysis was used to determine the threshold value for CHD, and sensitivity and specificity were calculated.

Results

CHD measurement had a good interobserver reliability (Intraclass correlation coefficient 0.799). Mean CHD was highly significantly (P < .001) less for test group a (mean 7.3 mm, standard deviation ± 2.2) compared with control group b (mean 11.1 mm, standard deviation ± 2.3) or zero-sample group c (mean 13.6 mm, standard deviation ± 2.9). A threshold value of CHD <9.5 mm had a sensitivity of 83.6% and a specificity of 83.9% to predict SSC tears.

Conclusion

A CHD <9.5 mm on MRI is predictive of SSC lesions and a valuable tool to diagnose SSC tears.

Increased Glenoid Index as a Risk Factor for Pediatric and Adolescent Anterior Glenohumeral Dislocation: An MRI-Based, Case-Control Study

Background:

In adults, anterior glenohumeral instability has been associated with a tall and narrow glenoid morphology, assessed using the glenoid index (GI; glenoid height-to-width ratio) on magnetic resonance imaging (MRI). This morphological association has not been assessed in children and adolescents.

Purpose/Hypothesis:

To examine the association of GI and other MRI measurements of interest supported in studies on adults with anterior glenohumeral dislocation in patients aged ≤19 years. We hypothesized that these patients would have a significantly greater GI (relatively taller and narrower glenoid morphology) compared with healthy controls.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

An institutional radiology database was queried over a 10-year period to identify patients aged ≤19 years who had been diagnosed with radiographically confirmed anterior shoulder dislocation and who underwent glenohumeral magnetic resonance arthrography as well as those without dislocation with normal shoulder arthrogram studies (controls). Patients with bony Bankart lesions were excluded. The following glenohumeral dimensions were measured on shoulder arthrogram: GI, glenoid version, coracohumeral interval, and rotator interval width/depth. Comparative analysis between the 2 groups was performed using the Student t test for each variable, followed by receiver operating characteristic (ROC) analysis to determine discriminative ability when statistically significant.

Results:

Overall, 55 participants (33 male and 22 female patients; mean age, 15.4 ± 2.1 years) were enrolled; 22 patients were in included in the dislocator group and 33 patients comprised the control group. The mean GI in the dislocator group was significantly greater than the control group (1.55 ± 0.14 vs. 1.38 ± 0.08; P < .001). ROC analysis revealed adequate discrimination of GI in predicting glenohumeral dislocation (area under the curve = 0.88). A GI ≥1.45 was 83% sensitive and 79% specific for predicting dislocation in the study cohort.

Conclusion:

Patients with anterior glenohumeral dislocation had increased GI (taller and narrower glenoid morphology) than controls. This useful MRI measurement may help identify patients at risk for primary or recurrent anterior glenohumeral instability events and may therefore help with guiding treatment and prevention.

Measurement of the coracohumeral distance on magnetic resonance imaging in a large patient cohort

BACKGROUND

Coracoid impingement syndrome is an increasingly recognized etiology of anterior shoulder pain. Numerus studies have documented the coracohumeral distance (CHD) as a primary or secondary measurement in symptomatic individuals, but there lacks an evaluation of CHD in a large cohort of asymptomatic individuals. The purpose of this study was to quantify a normative distribution of the CHD in a large cohort of healthy, asymptomatic subjects with no history of impingement or shoulder instability.

METHODS

Incoming first-year students in the United States Military Academy were offered enrollment in this study as part of a prospective cohort to assess the normal anatomic relationships of the shoulder girdle. Magnetic resonance images were obtained, and a board-certified, fellowship-trained musculoskeletal radiologist performed measurements of the smallest distance from the coracoid to the humeral head on axial images.

RESULTS

Magnetic resonance images of 714 subjects were available for analysis, including 630 males and 84 females, with a total of 1120 individual shoulders with images of adequate quality. The mean CHD for all shoulders imaged was 13.7 mm. The mean CHD in male shoulders was 13.8 mm, and in female subjects the average was 12.4 mm.

CONCLUSIONS

This study is the largest of its kind to evaluate the CHD in asymptomatic, healthy shoulders to date and demonstrates a mean CHD of 13.7 mm for all subjects. This information can help to standardize "normal" ranges and act as a comparison for future work, when taken in the context of age and imaging in neutral rotation.

Diagnosis and Management of Subcoracoid Impingement

Impingement of the subcoracoid space is a poorly understood pathologic cause of anterior shoulder pain. Because of its relative rarity in isolation and nonspecific presentation, diagnosis and management are often challenging for orthopaedic surgeons and their patients. Stenosis of the subcoracoid space between the lesser tuberosity and the coracoid process <6 mm can lead to anterior shoulder pain and associated rotator cuff and biceps pathology. Multiple imaging modalities are available to assess narrowing of the coracohumeral interval, each with its strengths and limitations. If the patient can be accurately diagnosed with subcoracoid impingement, both conservative and surgical management options are available. Despite earlier case series demonstrating promising results with arthroscopic treatment, comparative studies have yet to support these initial claims.

Do coracohumeral interval and glenoid version play a role in subscapularis tears?

Purpose

To study the effect of the coracohumeral interval and orientation of the glenoid for causation of subscapularis tears and literature review for the need of coracoplasty.

Methods

This is a retrospective cohort study of patients who underwent arthroscopic shoulder surgery from January 2013 to December 2017. The coracohumeral interval and orientation of the glenoid in patients with arthroscopically diagnosed subscapularis tears (group A, n = 40) were compared with 2 control groups (group B, n = 38 [intact subscapularis with supraspinatus and infraspinatus cuff tears] and group C, n = 39 [intact rotator cuff]). Group A1 (n = 23) consisted of the isolated subscapularis and combined subscapularis + supraspinatus tears, and group A2 (n = 17) all the 3 rotator cuff tears. The measurements were made on preoperative axial magnetic resonance imaging. Statistical analysis was performed to compare the groups.

Results

The mean coracohumeral interval was 8.81 ± 2.69 mm in group A and 10.62 ± 2.21 and 10.39 ± 2.59 mm in control groups B and C, respectively; this difference was statistically significant (P = .002 and .01, respectively). The mean glenoid version in patients with subscapularis tears was -3.7°, whereas the mean version in patients with intact cuff was -3.4°, and this difference was not statistically significant (P = .74). The mean glenoid version was -4.69° ± 4.22° in group A1 and -3.28° ± 4.04° in group B, with no statistically significant difference (P = .07).

Conclusion

The coracohumeral interval was significantly decreased in patients with subscapularis tears. The glenoid was retroverted in the subscapularis group but was not statistically significant.

Coracohumeral distance and coracoid overlap as predictors of subscapularis and long head of the biceps injuries

BACKGROUND

Subscapularis (SS) lesions are often underdiagnosed because of an incomplete understanding of contributing factors but also because of a greater difficulty in SS tear diagnosis with magnetic resonance imaging or physical examination. In this setting, predicting factors can be useful tools in these injuries' management. The goal of this study was to determine the influence of the coracohumeral distance (CHD) and coracoid overlap (CO) in anterior rotator cuff lesions, as well as to determine the CHD and CO values that can accurately predict SS and long head of the biceps (LHB) injuries.

METHODS

We performed a retrospective, controlled, single-blinded study. We analyzed 301 patients with rotator cuff pathology and magnetic resonance imaging studies; patients with SS lesions represented the study group. The CHD and CO were measured.

RESULTS

We found that lower CHD and higher CO values were progressively related to more serious injuries of the SS and LHB. The CHD was a very strong predictor of SS injury and tear and a good predictor of LHB injuries. A CHD of 7.6 mm had a sensitivity of 84.4% and specificity of 88.6% for SS tears. The CO was also a very strong predictor of SS tears and a good predictor of LHB injury, with a CO of 16.6 mm reaching a sensitivity of 77.8% and specificity of 68.3% for SS tears.

CONCLUSIONS

The CHD is an excellent predictor of SS tears and a good predictor of LHB lesions, with the CO also being a very strong predictor of SS tears and a good model for LHB injuries.

Overuse Injuries of the Shoulder

This article discusses the most common and important overuse injuries of the shoulder with attention to MR imaging and ultrasound findings. Pathologic conditions occurring in athletes and nonathletes are included, with review of relevant anatomy, predisposing factors, and treatment considerations. Specific overuse injuries involving the rotator cuff, long head of the biceps tendon, and subacromial-subdeltoid bursa are reviewed. Impingement syndromes of the shoulder, Little Leaguer's shoulder, and stress-induced distal clavicular osteolysis are also discussed.

Subacromial impingement anatomy and its association with rotator cuff pathology in women: radiograph and MRI correlation, a retrospective evaluation

OBJECTIVE

To evaluate the relationships between acromial anatomy and developmental alterations with rotator cuff tears in female patients and compare these parameters on radiographs and corresponding MRIs along with inter-reader performance.

MATERIALS AND METHODS

Patient demographics, symptoms, and acromial characteristics on radiograph (acromial index, lateral acromion angle, subacromial space on AP and Y- views, acromial anterior and lateral downsloping) and MRI (shape, slope, spur, osteoarthrosis, os acromiale) were recorded. Radiographic and MRI findings were compared and correlated with rotator cuff pathology on MRI. Inter-reader analysis was performed.

RESULTS

A total of 140 MRIs from 137 female patients were included. No significant correlation (p > 0.05) existed between acromial parameters and rotator cuff tears, except for a smaller subacromial space on the Y view and spurs correlated with subscapularis tendon tear (p = 0.02, p = 0.04). The presence of lateral downsloping on MRI correlated with a smaller lateral acromion angle (p = 0.0002) and the presence of lateral downsloping on radiography (p = 0.0015). Inter-reader agreements were good to excellent (ICC: 0.65-0.89).

CONCLUSION

Subacromial impingement anatomy characteristics have no significant associations with supraspinatus or infraspinatus tears in symptomatic women. Among different measures, supine MRI can be reliably used to identify lateral downsloping of the acromion.

Magnetic resonance imaging based coracoid morphology and its associations with subscapularis tears: a new index

BACKGROUND

We aimed to assess the validity of magnetic resonance imaging (MRI) in assessing the subcorocoid space and determine the validity of novel sagittal plane subcorocoid space measurements.

METHODS

We assessed 33 arthroscopically proven subscapularis tears with MRIs compared to 33 (instability) controls with normal subscapularis tendons. Three examiners analyzed MRIs for seven static indices of corocoid morphology, in axial and sagittal planes. We explored reviewer variation using intraclass correlation coefficients (ICC) and differences between the two groups was explored using t-tests.

RESULTS

Groups were similar in characteristics but different in age (cases = 53, controls = 23). ICC showed good (2/7) or excellent (5/7) reliability. Small differences(<1.6 mm) were identified between subscapularis tears and controls in coraco-humeral distance, in axial (p = 0.092) and sagittal planes (p = 0.045). There were statistically significant differences between groups when analyzing the angular projection of the coracoid from the glenoid, in both sagittal (p < 0.0001) and axial planes (p = 0.045).

CONCLUSIONS

Acute inferior angulation of the corocoid in the sagittal plane may be associated with subscapularis tears. Static indices are measured within the scapula and not affected by arm position. MRI reliably provided a platform to assess the coracoid. Based on this, we currently consider corocoplasty in patients with subscapularis tears and a sagittal coroco-glenoid angle <60^o to reduce potential impingement.

Radiological Variabilities in Subcoracoid Impingement: Coracoid Morphology, Coracohumeral Distance, Coracoglenoid Angle, and Coracohumeral Angle

BACKGROUND The aim of this study was to investigate the effects of coracoid morphology, coracohumeral distance, coracoglenoid angle, and coracohumeral angle variabilities on subcoracoid impingement development using magnetic resonance imaging (MRI). MATERIAL AND METHODS A total of 200 patients (87 males with mean age of 51.1±15.2 years and 113 females with mean age of 52.6±10.7 years) undergoing shoulder MRI were included in this retrospective study. All MRI studies were performed with standard positioning. Coracoid morphology and subscapularis tendon were evaluated. Coracohumeral distance, coracoglenoid angle and coracohumeral angle were measured in all subjects. One-way ANOVA was used to assess the difference between the groups. For binary comparisons, Tukey post hoc analysis was done. Pearson correlation analysis was performed between variables. RESULTS Type C coracoid was more frequent in the tendinosis and tendon tear groups. There was a significant difference between type C coracoid and the other coracoid types for coracohumeral distance values (P=0.016). There was a statistically significant decrease in coracoglenoid angle values and coracohumeral distance in patients with subscapularis tendon pathologies (P=0.000). A statistically insignificant increase in coracohumeral angle values was found in the subscapularis tendon pathologies. There was a positive correlation between coracohumeral distance and coracoglenoid angle (R=0.749 P=0.000). There was a negative correlation between coracohumeral distance and coracohumeral angle (R=-0.668 P=0.000) and between coracoglenoid angle and coracohumeral angle (R=-0.605 P=0.000). CONCLUSIONS In subscapularis tendon pathologies, decrease in coracohumeral distance and coracoglenoid angle was observed. A new approach uses coracohumeral angle to evaluate subcoracoid impingement. A statistically insignificant increase in coracohumeral angle was noted.

Anatomic Study of Subcoracoid Morphology in 418 Shoulders: Potential Implications for Subcoracoid Impingement

Background:

Subcoracoid impingement has been implicated as a cause of anterior shoulder pain and subscapularis tendon tears.

Purpose/Hypothesis:

The purpose of this study was to evaluate the bony anatomy of the coracoid process and the subcoracoid space. We hypothesized that age-related changes that may contribute to subcoracoid impingement occur in the subcoracoid space.

Study Design:

Descriptive laboratory study.

Methods:

In total, 418 skeletal shoulder specimens were included in this study. We utilized 214 shoulders from a young cohort (25-35 years of age) and 204 shoulders from an older cohort (>55 years of age) for comparison. We evaluated several morphological characteristics of the coracoid process and the subcoracoid space: coracoid width, coracoid shape, coracoid thickness, and subcoracoid distance. Each coracoid was observed for the presence of spurring or other morphological changes.

Results:

The mean anteroposterior (AP) thickness of the coracoid tip was 7.9 and 9.4 mm in our young female and male cohorts, respectively, while the mean AP thickness was 8.1 and 9.7 mm in our older female and male cohorts, respectively. The coracoid tip was hooked in 31 of 108 young female shoulders compared with 55 of 102 older female shoulders, and the coracoid tip was hooked in 25 of 106 young male shoulders compared with 45 of 102 older male shoulders. The mean subcoracoid distance in neutral rotation was 14.8 and 12.5 mm in young and older female shoulders, respectively, while the mean subcoracoid distance in internal rotation in these same cohorts was 8.7 and 7.0 mm, respectively. The mean subcoracoid distance in neutral rotation was 14.8 and 13.3 mm in young and older male shoulders, respectively, while the mean subcoracoid distance in internal rotation was 8.6 and 8.1 mm in young and older male shoulders, respectively.

Conclusion:

The principal findings of our study demonstrate that anatomic changes implicated in subcoracoid impingement may be developmental and worsen with age. The subcoracoid space was narrower in our older cohort of shoulders. Additionally, these older shoulders also had a greater AP width and a more hooked coracoid compared with young shoulders.

Clinical Relevance:

Narrowing of the subcoracoid space has been shown to be implicated as a cause of anterior shoulder pain and subscapularis tendon tears. This is the first study to show that the morphological changes implicated in subcoracoid impingement become more prevalent with age. This may help to explain the increasing prevalence of subscapularis tendon tears in older patients. Furthermore, subcoracoid decompression may be seen as an option for older patients with anterior shoulder pain and subscapularis tendon tears.

Dynamic ultrasonography of the shoulder

Ultrasonography (US) is a useful diagnostic method that can be easily applied to identify the cause of shoulder pain. Its low cost, excellent diagnostic accuracy, and capability for dynamic evaluation are also advantages. To assess all possible causes of shoulder pain, it is better to follow a standardized protocol and to perform a comprehensive evaluation of the shoulder than to conduct a focused examination. Moreover, a proper dynamic study can enhance the diagnostic quality of US, especially when the pathology is not revealed by a static evaluation. The purpose of this article is to review the common indications for dynamic US of the shoulder, and to present the basic techniques and characteristic US findings.

Is coracohumeral distance associated with pain-function, and shoulder range of movement, in chronic anterior shoulder pain?

BACKGROUND

The aim of this study was twofold: (i) to assess the intrarater reliability of coracohumeral distance; (ii) to investigate the level of association between coracohumeral distance measured by ultrasonography, and pain-disability and shoulder range of movement, in patients suffering from chronic anterior shoulder pain.

METHODS

An observational, cross sectional study was carried out. A convenience sample comprised of 87 patients with chronic anterior shoulder pain was assessed from 3 primary care centres. Main outcomes as pain and function were measured through the shoulder pain and disability index. Furthermore, shoulder range of movement-free of pain in shoulder elevation, as well as coracohumeral distance at both 0 and 60 degrees, were collected.

RESULTS

Absence of any correlation was found between coracohumeral distance and shoulder pain and disability index at both 0 and 60 degrees of shoulder elevation. Furthermore, absence of any correlation was found between coracohumeral distance measurements and active shoulder range of movement -free of pain.

CONCLUSIONS

There was poor association between coracohumeral distance and shoulder pain and function, as well as with shoulder range of movement, in patients with chronic anterior shoulder pain. Hence, clinicians should consider, not only increasing this space, but also other possibilities in their therapies, when patients with anterior shoulder pain are treated.

TRIAL REGISTRATION

ACTRN12614000144617 . Registered: 1^st March 2014.

Subscapularis Tendon Slip Number and Coracoid Overlap Are More Related Parameters for Subcoracoid Impingement in Subscapularis Tears: A Magnetic Resonance Imaging Comparison Study

PURPOSE

To investigate the effects of the subscapularis tendon slip number (STSN) and coracoid morphology by magnetic resonance imaging in patients with and without subscapularis tears.

METHODS

Patients who underwent shoulder arthroscopy between February 2004 and June 2015 were re-evaluated. Those with a subscapularis tear (study group) and those with other pathologies (control group) were compared with each other. Magnetic resonance imaging scans and surgery videos of the patients were reassessed. Transverse and sagittal coracohumeral distance (CHD), coracoid overlap (CO), coraco-coracoid base angle (CBA), coracoglenoid distance (CGD), and STSN were measured.

RESULTS

The study and control groups comprised 141 and 78 patients, respectively. The mean age was 57.01 ± 10.95 (similar in both the groups). The mean transverse CHD and sagittal CHD were not different between the groups and also between female and male patients. For the study and control groups, the mean CBA and CGD values were also similar. The mean CO was 24.01 ± 4.9 and 21.29 ± 4.58 for the study and control groups, respectively (P < .001). With the receiver operating characteristic curve of the CO, the sensitivity was 62% and the specificity was 64% at the cutoff value of 22.85 mm. The STSN was in the range between 1 and 6; the STSN was 3 or less in 61.5% of the study group and in 38.5% of the control group (P = .005).

CONCLUSIONS

The CO was the most valuable parameter predicting any potential subcoracoid impingement, and the STSN was inversely correlated with subscapularis tears. However, in predicting a potential subcoracoid impingement, the CHD measurements were not significant, as well the CGD and CBA.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Three-Dimensional Morphometric Analysis of the Coracohumeral Distance Using Magnetic Resonance Imaging

There have been no studies investigating three-dimensional (3D) alteration of the coracohumeral distance (CHD) associated with shoulder motion. The aim of this study was to investigate the change of 3D-CHD with the arm in flexion/internal rotation and horizontal adduction. Six intact shoulders of four healthy volunteers were obtained for this study. MRI was taken in four arm positions: with the arm in internal rotation at 0°, 45°, and 90° of flexion, and 90° of flexion with maximum horizontal adduction. Using a motion analysis system, 3D models of the coracoid process and proximal humerus were created from MRI data. The CHD among the four positions were compared, and the closest part of coracoid process to the proximal humerus was also assessed. 3D-CHD significantly decreased with the arm in 90° of flexion and in 90° of flexion with horizontal adduction comparing with that in 0° flexion (P<0.05). In all subjects, lateral part of the coracoid process was the closest to the proximal humerus in these positions. In vivo quasi-static motion analysis revealed that the 3D-CHD was narrower in the arm position of flexion with horizontal abduction than that in 0° flexion. The lateral part on the coracoid process should be considered to be closest to the proximal humerus during the motion.

Lesser tuberosity cysts and their relationship with subscapularis tears and subcoracoid impingement

BACKGROUND

We aimed to evaluate cysts in the lesser tuberosity of humeral head seen on magnetic resonance imaging (MRI) and their relationship with subcoracoid impingement and subscapularis tears evident on arthroscopic surgery videos. Our hypothesis was that the cysts would be more frequent with subscapularis tears and in the case of subcoracoid impingement.

METHODS

Patients who underwent shoulder arthroscopy between January 2010 and January 2016 were retrieved to evaluate subscapularis tears on surgery videos and lesser tuberosity cysts (LTC), coracohumeral distances (CHD) on both sagittal oblique and transverse sections of MRI retrospectively. There were 137 patients meeting the study criteria with subscapularis tear evident on surgery video and having preoperatively studied magnetic resonance images. All the tears were classified according to the Lafosse's system. The control group was constituted with 121 patients who underwent shoulder arthroscopy and were diagnosed with no subscapularis tear. Then, any statistically significant relationship between these parameters was investigated by the use of statistics software.

RESULTS

The mean age (57), gender distribution (female for 67.1%), and involved shoulder (right for 62.8%) rate of the groups were statistically similar. The existence rate of LTC was 55.5% and 19% for the study and control groups, respectively (P = .000). The study group was then evaluated in two groups regarding the existence of a cyst in the lesser tuberosity. There was no statistical difference between these two groups in terms of coracohumeral distances and tear type (P > .05). The study group was also divided into two depending on the transverse section CHD whether it was under 7 mm or not. There was still no statistical difference between these subgroups in terms of a cyst existence (P > .05). The supraspinatus tear rate and age distribution was also not differing in patients with and without LTC.

CONCLUSIONS

The LTCs were significantly associated with subscapularis tears, and could be used as an indicator in the interpretation of MRI scans. However, there was no relationship between the subcoracoid impingement and LTCs.

Magnetic Resonance Imaging of the Subcoracoid Region and Its Relationship with Subscapularis Lesions in the Chinese Population

Introduction

Coracoid impingement is considered a known yet frequently overlooked cause of anterior shoulder pain. Subcoracoid stenosis has been shown to be related to subscapularis tear. Studies have shown that patients with coracoid impingement have a shorter coracohumeral distance (CHD) and a larger coracoid overlap (CO) but these are based on data from Western populations. The aim of our study was to provide a local database on the MRI measurement of these parameters in our Chinese population and raise the awareness of this disease entity.

Methods

All the shoulder MRI films taken in our hospital in 2011 were retrospectively reviewed and classified into two cohorts. The control group consisted of patients who had no subscapularis lesion. The subscapularis lesion group consisted of patients with complete tear, partial tear or abnormal signal over the subscapularis tendon. The CHD and CO were measured.

Results

We reviewed 133 sets of shoulder MRI obtained in our hospital during 2011. Thirteen patients were noted to have subscapularis lesion. The CHD in the subscapularis lesion group was 6.24 ± 2.18 mm. The CHD in the control group was 9.95 ± 3.9 mm. Women had shorter CHD (8.18 ± 2.57 mm) than men (11.0 ± 4.54 mm). We failed to notice any statistically significant difference with regards to CO, coracoid process and lesser tuberosity morphology between the two groups of patients.

Conclusion

MRI assessment of CHD can be useful in identifying patients at risk of having subscapularis lesion and coracoids impingement.

Multi-modal imaging of the subscapularis muscle

Abstract

The subscapularis (SSC) muscle is the most powerful of the rotator cuff muscles, and plays an important role in shoulder motion and stabilization. SSC tendon tear is quite uncommon, compared to the supraspinatus (SSP) tendon, and, most of the time, part of a large rupture of the rotator cuff. Various complementary imaging techniques can be used to obtain an accurate diagnosis of SSC tendon lesions, as well as their extension and muscular impact. Pre-operative diagnosis by imaging is a key issue, since a lesion of the SSC tendon impacts on treatment, surgical approach, and post-operative functional prognosis of rotator cuff injuries. Radiologists should be aware of the SSC anatomy, variability in radiological presentation of muscle or tendon injury, and particular mechanisms that may lead to a SSC injury, such as coracoid impingement.

Teaching Points

• Isolated subscapularis (SSC) tendon tears are uncommon.

• Classically, partial thickness SSC tendon tears start superomedially and progress inferolaterally.

• Long head of biceps tendon medial dislocation can indirectly signify SSC tendon tears.

• SSC tendon injury is associated with anterior shoulder instability.

• Dynamic ultrasound study of the SSC helps to diagnose coracoid impingement.

Clinico-Radiological Correlation of Subcoracoid Impingement with Reduced Coracohumeral Interval and its Relation to Subscapularis Tears in Indian Patients

INTRODUCTION

Clinically, subcoracoid impingement is characterized by pain at the anterior aspect of the shoulder that is induced by adduction, internal rotation and forward flexion. This position leads to narrowing of the Coraco-Humeral Interval (CHI)-that is, the space between the coracoid process and the lesser tuberosity of the humerus. Structures in the rotator interval are at greatest risk for impingement which includes the Subscorapularis tendon, tendon of the long head of the biceps, and the middle gleno-humeral ligament. This may result in Rotator interval pathologies such as subscapularis tear and long head of biceps tendon subluxation or fraying.

AIM

To study the prevalence of radiological evidence of reduced Coraco-Humeral Interval (CHI) in patients with clinically evident Subcoracoid impingement and to examine the presence of Subscapularis tears in these patients.

MATERIALS AND METHODS

Twenty four patients (6 males, 18 females, average age 52.83 years) were included in this prospective study who were diagnosed to have rotator cuff tears clinically. Nine of these patients were clinically found to have concomitant subcracoid impingement. All patients were subjected to MRI of shoulder. Measurement of the CHI was done in images with humerus in maximal internal rotation. Presence of subscapularis tear was examined intraoperatively. Statistical evaluation of the data was performed using Student's t-test and Fisher's exact test and the results were applied to two cohorts of patients. One cohort consisted of patients who had a CHI value of less than 5.5mm and the other cohort had a CHI value greater than 5.5mm. Average CHI values in patients with and without a subscapularis tear were determined.

RESULTS

Nine patients who had clinical subcoracoid impingement were found to have an average CHI of 5.33mm. All nine of them had an associated tear of subscapularis with long head of Biceps tendon subluxation and/or fraying. Remaining 15 patients had an average CHI of 10.48 and they did not have either signs of Subcracoid impingement or subscapularis tear but had a tear elsewhere (Supraspinatus or Infraspinatus). Difference between these two groups was found highly significant (p-value<0.001). All patients with a CHI value of equal to, or less than 5.5mm had a subscapularis tear, whereas only 11% of patients with a CHI value more than 5.5mm had a tear (p-value<0.001, highly significant).

CONCLUSION

Reduction in the CHI has a significant association with rotator interval pathologies such as subscapularis tears and subluxation or fraying of long head of biceps tendon. Treatment of such patients should include modalities such as coracoplasty or anterior shoulder stabilisation. We recommend that clinical evidence of subcoracoid impingement should lead to further Investigation in the form of MRI and estimation of CHI. A CHI of less than 5.5 mm may indicate subscapulais tear in Indian patients.

Coracoid Process: The Lighthouse of the Shoulder

The coracoid process is a hook-shaped bone structure projecting anterolaterally from the superior aspect of the scapular neck. Surgeons often refer to the coracoid process as the "lighthouse of the shoulder" given its proximity to major neurovascular structures such as the brachial plexus and the axillary artery and vein, its role in guiding surgical approaches, and its utility as a landmark for other important structures in the shoulder. The coracoid also serves as a critical anchor for many tendinous and ligamentous attachments. These include the tendons of the pectoralis minor, coracobrachialis, and short head of the biceps brachii muscles, and the coracoclavicular, coracohumeral, coracoacromial, and transverse scapular ligaments. Consequently, the coracoid and its associated structures are linked to numerous shoulder pathologic conditions. This article will detail the anatomy of the coracoid and its associated structures and review the clinical and radiologic findings of corresponding pathologic conditions in this region with original illustrations and multimodality imaging examples. Highlighted in this article are the coracoclavicular joint, the classification and management of coracoid fractures, subcoracoid impingement, the coracoacromial arch and subacromial impingement, the coracohumeral ligament and the biceps pulley, the coracoclavicular ligament and its surgical reconstruction, adhesive capsulitis, the suprascapular notch and suprascapular notch impingement, subcoracoid bursitis, coracoid transfer procedures, and coracoid tumors. A brief summary of the pathophysiology, potential causes, and management options for each of the pathologic entities will also be discussed. ^©RSNA, 2016.

Beyond the Cuff: MR Imaging of Labroligamentous Injuries in the Athletic Shoulder

Shoulder disease is common in the athletic population and may arise as a consequence of a single traumatic episode or multiple repeated events. Associated labroligamentous injuries can result in substantial disability. Specific athletic and occupational activities result in predictable injury patterns. Imaging in general and magnetic resonance (MR) imaging, in particular, are vital in establishing the correct diagnosis and excluding common mimicking conditions, to ensure timely and appropriate management. In this review, the utility of MR imaging and MR arthrography will be explored in evaluation of shoulder disease, taking into account normal variants of the labroligamentous complex. Subsequently, broad categories of labral lesions and instability, external and internal impingement, as well as nerve entrapment syndromes, will be discussed, while emphasizing their imaging findings in the clinical context and illustrating key features. More recent concepts of internal impingement and secondary subacromial impingement will also be clarified.

The Coracohumeral Distance in Shoulders With Traumatic and Degenerative Subscapularis Tendon Tears

BACKGROUND

A reduced coracohumeral distance (CHD) is thought to be responsible for subcoracoid impingement. This only accounts for degenerative tendon tears. In traumatic tears, the subcoracoid space should be normal.

HYPOTHESIS

The CHD in patients with traumatic subscapularis tendon tears is larger than that in patients with degenerative tears and does not differ from patients with an intact subscapularis tendon.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 83 patients with arthroscopically certified subscapularis tendon tears were included in the study. Forty-four patients had degenerative causes (group 1), and 39 had traumatic causes (group 2). The control group consisted of 20 patients with traumatic supraspinatus tendon tears and arthroscopically proven, intact subscapularis tendons (group 3). On preoperative axial magnetic resonance imaging, the distance between the CHD was measured, and the values of the 3 groups were compared using the t test.

RESULTS

The mean (±SD) CHD in patients with degenerative subscapularis tendon tears was 8.6 ± 2.0 mm (range, 4.0-13.2 mm) and was significantly (P = .0003) smaller than that in patients with traumatic tears (10.2 ± 2.0 mm; range, 6.6-16.2 mm) or controls (10.4 ± 1.8 mm; range, 6.8-14.0 mm). The CHD of controls and patients with traumatic tears did not differ significantly (P = .7875). A CHD of less than 6 mm only occurred in patients with degenerative subscapularis tendon tears.

CONCLUSION

The hypothesis that the CHD in patients with degenerative subscapularis tendon tears is significantly smaller than that in patients with traumatic tears or intact subscapularis tendons was confirmed. The CHD in patients with traumatic tears does not differ from that in controls. A CHD of less than 6 mm only occurs in patients with degenerative subscapularis tendon tears.

Locations of lesser tuberosity cysts and their association with subscapularis, supraspinatus, and long head of the biceps tendon disorders

BACKGROUND

Humeral head cysts are not uncommon in individuals with rotator cuff disorders. The cysts are usually considered an indicator of rotator cuff pathologies; however, they may have different meanings in different regions.

PURPOSE

To determine the frequency of cysts within and adjacent to the lesser tuberosity and the relationship between these cysts and subscapularis, supraspinatus, and long head of the biceps tendon (LHBT) disorders.

MATERIAL AND METHODS

We retrospectively reviewed 760 consecutive shoulder magnetic resonance imaging (MRI) examinations. Among these MRIs, we selected a group of patients with cysts located around the lesser tuberosity. The study population was also divided into two subgroups, patients with cysts within the lesser tuberosity and those with cysts adjacent to the lesser tuberosity. In addition to the number and size of cysts, the MRI appearance of the tendons was evaluated.

RESULTS

Eighty-one (10.7%) patients had cysts within and/or adjacent to the lesser tuberosity, 34 (42%) patients had cysts within the lesser tuberosity, and 47 (58%) patients had cysts adjacent to it. LHBT and subscapularis tendon disorders were significantly related to more than one cyst. In a univariate analysis, cysts within the lesser tuberosity were significantly associated with LHBT and subscapularis tendon disorders; however, multivariate analyses showed that only LHBT disorders were significantly associated with cysts within the lesser tuberosity.

CONCLUSION

Cysts within the lesser tuberosity were less common than cysts adjacent to it. LHBT and subscapularis tendon disorders were more frequently found in patients with more than one cyst within and/or adjacent to the lesser tuberosity. In addition, cysts within the lesser tuberosity were associated with LHBT disorders.

A new method for measurement of subcoracoid outlet and its relationship to rotator cuff pathology at MR arthrography

OBJECTIVE

Orthopaedic surgical studies have shown that variations in the vertical distance between the tip of the coracoid process and the supra-glenoid tubercle alter the shape of the subcoracoid outlet. Our objective was to measure the vertical distance between the coracoid tip and the supra-glenoid tubercle (CTGT) on MR and to assess whether this showed better correlation with rotator cuff pathology compared with the axial coraco-humeral distance.

MATERIALS AND METHODS

A retrospective review was performed of 100 consecutive shoulder MR arthrograms. Vertical distance between the coracoid tip and the supraglenoid tubercle was measured in the sagittal oblique plane. Separate assessment was then made of tendon pathology of the subscapularis, supraspinatus and long head of biceps tendons. Axial coraco-humeral distance was then measured. Correlation between tendon abnormalities and the two measurements was then made.

RESULTS

Of the 100 cases, 42 had subscapularis tendon lesions, 21 had lesions of the long head of biceps and 53 had supraspinatus tendon lesions. Mean vertical distance from the coracoid tip to supraglenoid tubercle was greater in those with lesions of any of these tendons and was statistically significant for the supraspinatus group (P = 0.005). Reduced axial coraco-humeral distance was also seen in patients with tendinopathy, although with less statistically significant difference (p = 0.059).

CONCLUSION

Our results support orthopaedic studies that have shown that the vertical distance between the coracoid tip and the supraglenoid tubercle increases the incidence and risk of rotator cuff disease by altering the shape of the subcoracoid outlet.

Accuracy of preoperative MRI in the diagnosis of disorders of the long head of the biceps tendon

OBJETIVES

To evaluate the accuracy of magnetic resonance imaging (MRI) in the detection of disorders of the long head of the biceps tendon (LHBT). The secondary objective was to investigate predictive factors for tears and instability.

METHODS

This retrospective case series involved patients undergoing shoulder arthroscopy due to rotator cuff injury. MRI was performed in a 1.5T scanner and was evaluated by a musculoskeletal radiologist. The findings were compared with those of arthroscopic inspection.

RESULTS

A total of 90 shoulders were analyzed. Regarding tears, there was 67% sensitivity and 98% specificity. Regarding instabilities, the values were 53% and 72%, respectively. Tears and fatty degeneration of the infraspinatus are predictive factors for tears of the LHBT. Tears of the subscapularis and infraspinatus, retraction of the supraspinatus and infraspinatus equal to or greater than 30mm, and fatty degeneration of the infraspinatus and subscapularis are predictive factors for instability.

CONCLUSION

Compared to arthroscopy, the shoulder MRI has a sensitivity of 67% and a specificity of 98% for the detection of complete tears of the LHBT. For instability, the values are 53% and 72%, respectively.

MRI analysis of coracohumeral interval width and its relation to rotator cuff tear

OBJECTIVE

Coracoid impingement is an uncommon cause of the shoulder pain. It is stimulated by adduction, internal rotation and forward flexion. These positions decrease the width of the coracohumeral interval. Owing to restriction of movement, rotator cuff tendons may be overloaded. Thus, in this study, we aimed to determine whether coracoid impingement increase the tendency of rotator cuff tears.

MATERIALS AND METHODS

Routine clinical MRI sequences of 117 shoulders were reviewed, and axial coracohumeral interval measurements were taken. Rotator cuff tendon integrity was evaluated. Relation between rotator cuff tear and coracohumeral interval width was commented statically.

RESULTS

Seventy-nine of the patients were women, 38 of them men. The average age was 44.8 ± 14.2 (14-75). The mean age of patients with rotator cuff tear was significantly higher than patients without tear (p = 0.001). The mean value of coracohumeral interval width was 8.853 ± 2.491 mm (min: 2.9-max: 15.8). There were no significant differences between coracohumeral interval width of women and men (p = 0.139). The mean value of coracohumeral interval width with rotator cuff tear was 8.362 ± 2.382, and without tear was 9.351 ± 2.520. There was a significant differences between them (p = 0.031).

CONCLUSION

According to our study, there was a relationship between coracohumeral interval width and rotator cuff tear, so decreasing coracohumeral interval width may increase tendency of rotator cuff tear.

Subcoracoid impingement and subscapularis tendon: is there any truth?

Subcoracoid impingement and stenosis have been described related to anterior shoulder pain and subscapularis tendon tears, but the pathogenesis and related treatment of this condition has still not been explained properly. Variability of coracoid morphology has been described and both traumatic and iatrogenic factors can modify it. Some authors referred this to a primary narrow coracohumeral distance with different threshold values defined as increased risk factor for subscapularis and antero-superior RC tear; opposite theories stated that the stenosis is secondary to an anterosuperior translation of the humeral head toward the coracoid due to degenerative changes of the rotator cuff tendons. Limited coracoplasty can be performed when related risk factors are identified; however no clear consensus arises from specific literature review and extensive clinical and instrumental examination of the patient should be performed in order to identify specific risk factors for subscapularis tendon pathology and, subsequently, tailor the proper approach.

Coracohumeral Distances and Correlation to Arm Rotation: An In Vivo 3-Dimensional Biplane Fluoroscopy Study

Background:

Reduced coracohumeral distances have been reported to be associated with anterior shoulder disorders such as subscapularis tears, biceps tendon injuries, and leading edge supraspinatus tears.

Purpose:

To determine the variability in coracohumeral distance as a function of arm rotation in healthy male subjects. The null hypothesis was that no differences in coracohumeral distance would exist with respect to arm rotation.

Study Design:

Descriptive laboratory study.

Methods:

A total of 9 male participants who had full range of motion, strength, and no prior surgery or symptoms in their tested shoulders were enrolled in this institutional review board–approved study. Computed tomography scans of the shoulder were obtained for each subject. A dynamic biplane fluoroscopy system recorded internal and external shoulder rotation with the arm held in the neutral position. Three-dimensional reconstructions of each motion were generated, and the coracohumeral distance and coracoid index (lateral extension of the coracoid) were measured.

Results:

The mean coracohumeral distance in neutral rotation was 12.7 ± 2.1 mm. A significantly shorter minimum coracohumeral distance of 10.6 ± 1.8 mm was achieved (P = .001) at a mean glenohumeral joint internal rotation angle of 36.6° ± 19.2°. This corresponded to a reduction in coracohumeral distance of 16.4% (range, 6.6%-29.8%). The mean coracoid index was 14.2 ± 6.8 mm. A moderate correlation (R = −0.75) existed between the coracohumeral distance and coracoid index.

Conclusion:

Coracohumeral distance was reduced during internal rotation. Decreased coracohumeral distance was correlated with larger coracoid indices.

Clinical Relevance:

This study provides a reference value for coracohumeral distance in the healthy male population. Knowledge of how coracohumeral distance varies over the range of arm internal-external rotation may improve the clinical diagnosis and treatment plan for patients with anterior shoulder pathology, specifically subcoracoid impingement. Imaging of the coracohumeral distance during internal rotation with the hand at approximately midline should be considered to assess patients with anterior shoulder pain.

MRI study of associated shoulder pathology in patients with full-thickness subscapularis tendon tears

Subscapularis tendon tears are a well-established cause of shoulder pain. The objective of the current study was to evaluate the associated shoulder pathology in patients with full-thickness subscapularis tendon tears using magnetic resonance imaging. Forty-seven magnetic resonance imaging studies taken between 2008 and 2009 with a diagnosis of full-thickness subscapularis tendon tears were reviewed. The size of the subscapularis tendon tear, amount of muscle volume loss, Goutallier grade, biceps tendon pathology, coracohumeral distance, and associated rotator cuff tears were recorded. Statistical analysis was performed. Patients 55 years and older vs those 54 years and younger had an average subscapularis tear size of 35 vs 19 mm, an average Goutallier grade of 2.7 vs 0.8, and a total muscle volume loss of 25% vs 5%, respectively. Patients with a dislocated vs normal biceps tendons had an average subscapularis tear size of 37 vs 23 mm, an average Goutallier grade of 3 vs 0.9, and a total muscle volume loss of 28% vs 7%, respectively. Patients with vs without concomitant rotator cuff tears had an average subscapularis tear size of 32 vs 17 mm, an average Goutallier grade of 2.3 vs 0.6, and a total muscle volume loss of 21% vs 3%, respectively. Overall average coracohumeral distance measured in the axial plane was 10.8±4.6 mm. Average coracaohumeral distance was 14.8 vs 8.1 mm in patients with a Goutallier grade of 0 vs 3 or 4, resepectively, and 13.6 vs 8.5 mm in patients with no rotator cuff tear vs those with a supra- and infraspinatus tear, respectively. Increased age, dislocated biceps tendons, and concomitant rotator cuff tears in patients with full-thickness subscapularis tendon tears are associated with larger subscapularis tendon tear size, higher Goutallier grades, and increased subscapularis muscle volume loss. Decreased coracohumeral distance is associated with a higher Goutallier grade and rotator cuff tears.

Throwing injuries of the upper extremity

The overhead throwing motion is a complex sequence of maneuvers that requires coordinated muscle activity in the upper and lower extremities. The shoulder and elbow are subject to multidirectional forces and are particularly vulnerable to injury during specific phases of the overhead throwing motion. Ligamentous, tendinous, neural, and osseous pathology that may occur in the shoulder or elbow of an overhead-throwing athlete will be discussed, with an emphasis on the role of MR imaging and MR arthrography.

MRI of selected abnormalities at the anterior superior aspect of the shoulder: potential pitfalls and subtle diagnoses

OBJECTIVE

MRI has proven to be a helpful tool in the detection and description of pathologic changes of the rotator cuff, biceps tendon, and glenoid labrum and has thus become a mainstay in the evaluation of patients with shoulder pain. This review seeks to illustrate some of the more subtle abnormalities that can be detected on shoulder MRI and to highlight some normal anatomic variants that may mimic pathologic processes, concentrating on structures at the anterior superior aspect of the shoulder.

CONCLUSION

Shoulder MRI can provide a very accurate evaluation of shoulder pathologic processes and can assist in elucidating abnormalities that can be difficult to diagnose clinically. Awareness of the known anatomic variants and the sometimes subtle potential pain generators at the anterior superior aspect of the shoulder will allow a more accurate interpretation and can therefore increase the diagnostic yield of shoulder MRI.

Coracoid impingement: current concepts

For many years, coracoid impingement has been a well-recognized cause of anterior shoulder pain. However, a precise diagnosis of coracoid impingement remains difficult in some cases due to the presence of multifactorial pathologies and a paucity of supporting evidence in the literature. This review provides an update on the current anatomical and biomechanical knowledge regarding this pathology, describes the diagnostic process, and discusses the possible treatment options, based on a systematic review of the literature. Level of evidence V.

Imaging evaluation of the rotator cuff

The rotator cuff is a complex network of interwoven tendons that plays a key role in glenohumeral movement and stability. Cuff abnormality is a common source of shoulder pain, but the clinical presentation is often nonspecific and, as a result, diagnostic imaging, especially magnetic resonance imaging, plays a key role in evaluating these patients. This article reviews imaging modalities available for evaluating the cuff, normal cuff anatomy, and common pathologic conditions that affect it.

Prevalence of the association of subacromial impingement with subcoracoid impingement and their clinical effects

OBJECTIVES

A prospective study to determine how commonly chronic subacromial impingement is associated with subcoracoid impingement and to evaluate clinical outcome after arthroscopic subacromial decompression (ASD).

METHODS

Subacromial and coracohumeral distances were evaluated in patients with chronic shoulder pain before and after ASD, using magnetic resonance imaging and the University of California at Los Angeles (UCLA) shoulder scale and Constant-Murley shoulder assessment.

RESULTS

A total of 40 patients were included in the study; patients were followed up for a mean of 27.3 months. Before ASD, 14 (35%) patients with chronic subacromial impingement also had subcoracoid impingement. In these patients, the mean coracohumeral distance was 7.18 mm (range 5.00 - 11.00 mm). After ASD, no patient had subcoracoid impingement, and the mean coracohumeral distance was significantly longer than pre-ASD, 12.85 mm (range 11.00 - 15.00 mm). The Constant-Murley shoulder assessment and UCLA shoulder scale both showed improvement after ASD.

CONCLUSIONS

Chronic subacromial impingement occurred together with subcoracoid impingement in 35% of patients presenting with chronic shoulder pain. Following ASD, the coracohumeral distance increased with remission from pain.

The rotator interval and long head biceps tendon: anatomy, function, pathology, and magnetic resonance imaging

The rotator interval is an anatomically defined triangular area located between the coracoid process, the superior aspect of the subscapularis, and the anterior aspect of the supraspinatus. It is widely accepted that the rotator interval structures fulfill a role in biomechanics and pathology of the glenohumeral joint and long head biceps tendon. However, there is ongoing debate regarding the biomechanical details and the indications for treatment. A better understanding of rotator interval anatomy and function will lead to improved treatment of rotator interval abnormalities, and guide the indications for imaging and surgical intervention.