Abnormalities on MRI of the subscapularis tendon in the presence of a full-thickness supraspinatus tendon tear

OBJECTIVE: Our objective was to determine the association between size and chronicity of full-thickness supraspinatus tendon tears with subscapularis tendon abnormalities on MRI. MATERIALS AND METHODS: One hundred forty-two MRI examinations with full-thickness supraspinatus tendon tears were categorized on the basis of the supraspinatus muscle (SS): normal muscle (SS(normal)), suggesting a recent or small tear; reduced muscle bulk without fatty atrophy (SS(volume loss)); and those with fatty atrophy, suggesting a large or chronic tear (SS(fatty atrophy)). Subscapularis tendon abnormalities, the subcoracoid interval, and subcortical bone marrow edema in the lesser tuberosity and coracoid process were recorded. RESULTS: The mean size of supraspinatus tendon tears in the SS(normal) (n = 45) group was 8.5 mm, 16.6 mm in SS(volume loss) (n = 53), and 29 mm in the SS(fatty atrophy) group (n = 44). Subscapularis tendon abnormality was identified in 22% of SS(normal) patients, 61% of SS(volume loss), and 86% of the SS(fatty atrophy) group (p < 0.001). There was moderate correlation between chronicity of supraspinatus tendon tears and subscapularis tendon abnormality (r = 0.47; p < 0.0001), with no correlation between the subcoracoid interval and abnormalities of the subscapularis tendon. There was moderate correlation between chronicity of supraspinatus tendon tears and bone marrow changes in the lesser tuberosity (r = 0.44; p < 0.0001). CONCLUSION: Subscapularis tendon abnormality is related to chronicity of supraspinatus tendon tears. Bone marrow edema in the lesser tuberosity with a subscapularis tendon abnormality suggests increased stress at the subscapularis tendon insertion with chronicity of full-thickness supraspinatus tendon tears. Lack of correlation with the subcoracoid interval indicates that anterior instability may be a more important contributing factor to subscapularis tendon abnormalities than static subcoracoid impingement in the setting of a full-thickness supraspinatus tendon tear.     

Narrowed coraco-humeral distance on MRI: Association with subscapularis tendon tear

Purpose

To highlight the relationship between coraco-humeral distance and subscapularis tendon tear.

Full-thickness tears of the rotator cuff of the shoulder: diagnosis with MR imaging.

The purpose of this study was to describe MR findings in full-thickness tears of the rotator cuff. Of 102 shoulders examined by MR imaging, 31 were found to have a full-thickness tendon tear at arthroscopy/bursoscopy (five shoulders) or open surgery (26 shoulders). All shoulders were imaged in oblique coronal and axial planes. MR images of the 102 shoulders were evaluated for (1) the presence of fluid in the subacromial and subdeltoid bursae; (2) abnormal signal of the supraspinatus, subscapularis, infraspinatus, and teres minor tendons; (3) interruption of tendon continuity and thinning of the tendon; and (4) proximal retraction of the junction of the muscle and tendon. The presence or absence of each finding was determined by consensus of two radiologists, who interpreted the images without knowledge of the surgical findings. Results in those 31 shoulders with proved full-thickness tears were: fluid in the subacromial bursae (29 shoulders), interruption of tendinous continuity (22 shoulders), focally increased signal of the tendon equivalent to that of water (27 shoulders), and musculotendinous retraction (24 shoulders). The finding of subacromial fluid was a sensitive indicator (93%) of a full-thickness tear, and interruption of tendinous continuity was a specific finding (96%) in diagnosing a full-thickness tear. Our experience shows interruption of tendon continuity is the most specific MR finding of full-thickness rotator cuff tears, while subacromial fluid is the most common finding.     

Correlation of MRI with arthroscopy for the evaluation of the subscapularis tendon: a musculoskeletal division’s experience

Objective

To determine the accuracy of MR imaging for the evaluation of the subscapularis tendon as well as define imaging findings that will increase accuracy.

Materials and methods

Retrospective review of the MR and operative (OR) reports of 286 patients was conducted and reviewed for the presence/degree (partial (PT)/full-thickness (FT)) of tearing; only PT articular tears were included. The presence of a supraspinatus tear and time interval between surgery and MRI were also documented. All of the PT tears called on MRI were also reviewed to see if there was a statistically significant association between certain imaging characteristics and the presence of a tear in surgery. Statistical analysis included 95 % confidence intervals, Fisher’s exact, and exact Mann–Whitney tests.

Results

A total of 244 patients were included in the study with a total of 25 subscapularis tears, 16 PT and nine FT, and 219 intact tendons in arthroscopy; 20/25 tears and 200 intact tendons were diagnosed correctly on MRI, resulting in sensitivity of 80 %, specificity of 91 %, accuracy of 90 %, positive predictive value of 51 %, and negative predictive value of 98 %. There was a significant association between the presence of a PT tear during arthroscopy and fluid-like signal within the tendon on more than one imaging plane (p?<?0.001) with an accuracy of 90 %.

Conclusions

This study reflects a musculoskeletal radiology section’s experience with the diagnosis of subscapularis tendon pathology, demonstrating that MRI could be used to accurately evaluate the subscapularis tendon. An understanding of certain imaging pitfalls and the presence of fluid-like signal on multiple imaging planes should increase the diagnostic accuracy of the radiologist evaluating the subscapularis tendon for the presence of a tear.     

MR evaluation of subscapularis tears.

PURPOSE: The purpose of this work was to describe the MR appearance of tears of the subscapularis tendon and compare the usefulness of different imaging planes as well as note the association of subscapularis tears with other rotator cuff tears and biceps tendon dislocations. METHOD: MR studies at 1.5 T over an 8 year interval were retrospectively assessed for the presence of a rotator cuff tear and/or tear of the subscapularis tendon. Images that showed a subscapularis tear were reviewed for the presence of a visible tear separately on the axial, coronal, and sagittal images. The MR studies were also evaluated for associated tears of the supraspinatus, infraspinatus, and teres minor muscles as well as biceps tendon dislocation and the "naked humerus sign" on coronal images. Last, clinical records and surgical reports were reviewed. RESULTS: Forty-five (2%) of 2,167 rotator cuff tears involved the subscapularis; 27% were partial and 73% were complete tears. Tears were best seen in the sagittal oblique plane. Almost all subscapularis tears were an extension of typical rotator cuff tears: supraspinatus in 35 patients (79%), extending into infraspinatus tears in 25 (56%) and into teres minor tears in 2 patients (4%). Bicipital dislocations were seen in 22 patients (49%), and three complete tears of the biceps (7%) were noted as well. The naked humerus sign was demonstrated in 31 patients (69%). Surgical reports that confirmed the MR findings were available for 15 patients. CONCLUSION: About 2% of rotator cuff tears involve the subscapularis tendon. Most subscapularis tears are extensions of supraspinatus tears and frequently involve the biceps tendon.     

Quantitative measurement of humero-acromial,humero-coracoid,and coraco-clavicular intervals for the diagnosis of subacromial and subcoracoid impingement of shoulder joint

Objective and purposeThe aim of this study was to determine the acromio-humeral, coraco-humeral, and coraco-clavicular distances with magnetic resonance imaging (MRI) in the diagnosis of shoulder impingement syndrome.Subjects and methodsAll the acromio-humeral, coraco-humeral, and coraco-clavicular intervals of all patients were reviewed retrospectively. A total of 132 shoulders (76 right and 56 left shoulders) with impingement syndrome (40 males and 92 females, with 79 cases surgically confirmed and the remaining 53 cases clinically and radiologically suspected) and 40 control group patients were included. Statistical correlation of this research was assessed by Fisher's Exact t test and Pearson chi-square test-correlation coefficients.ResultsIn the correlation of average acromio-humeral, coraco-humeral, and coraco-clavicular intervals (AHI, CHI, and CCI, respectively), there were significant statistical differences between patient and control groups; all the intervals were found to be higher in the control group. A moderate positive relation between average AHI and CHI, between AHI and CCI, and between CCI and CHI has been found. All intervals in the patient group increase or decrease dependently on each other. No proper cut-off values were determined using a receiver operating characteristic curve for all intervals between patient and control groups.ConclusionAcromio-humeral, coraco-humeral, and coraco-clavicular intervals were extremely lower in the shoulder impingement syndrome and had significant importance in the diagnosis of subacromial and subcoracoid impingements.     

Subscapularis tendon tear: primary and associated signs on MRI

PURPOSE: The purpose of this work was to investigate signs of subscapularis tendon tear on MRI. METHOD: Preoperative written interpretations of high field (n = 9) and low field (n = 7) MRI of 16 patients with tears confirmed at surgery or arthroscopy were reviewed, followed by retrospective review of these studies. RESULTS: A preoperative diagnosis of subscapularis tear was made in five (31%) cases. On retrospective review, primary signs of tear were present in 15 (94%) cases and in two-thirds were limited to the cranial third of the tendon. Supraspinatus tears were present in 69% of cases. Associated findings included medial dislocation (n = 4) or subluxation (n = 3) of biceps tendon, biceps tendinopathy (n = 2), superior labral tear (n = 5), and effusions of superior subscapularis recess (n = 6), subcoracoid bursa (n = 2), or both (n = 5). One or more associated signs were present in 94% of cases. CONCLUSION: Subscapularis tear is frequently missed on MRI. Recognizing that primary signs of tear may be limited to the cranial third of the subscapularis tendon and identifying associated signs should facilitate diagnosis.     

Shoulder impingement syndrome: MR findings in 53 shoulders

The shoulder impingement syndrome refers to a condition in which the supraspinatus tendon and subacromial bursa are chronically entrapped between the humeral head inferiorly and either the anterior acromion itself, spurs of the anterior acromion or acromioclavicular joint, or the coracoacromial ligament superiorly. As a result, the space for the bursa and tendon is reduced, and repeated trauma to these structures leads to bursitis and rotator cuff injury. Although pain and limitation of motion are common early findings, the diagnosis is often delayed until a complete tear of the rotator cuff has occurred. In an attempt to determine if MR can be used to depict the abnormalities associated with impingement syndrome (subacromial bursitis, supraspinatus tendinitis, and rotator cuff tear), we reviewed 107 MR scans of painful shoulders. Changes consistent with impingement syndrome were found in 53 patients (50%), 32 of whom underwent subsequent arthrography or surgery. MR was found capable of depicting several soft-tissue and bony abnormalities that have been clinically described in impingement syndrome. In regions of inflammation, we found that the supraspinatus tendon and/or the subacromial bursa were compressed by spurs (25 shoulders), capsular hypertrophy of the acromioclavicular joint (six shoulders), and/or low-lying acromion (14 shoulders). While T1-weighted MR imaging was highly sensitive to abnormalities of the supraspinatus tendon, tendinitis could be differentiated from a small tear of the supraspinatus tendon only with T2-weighted imaging. Large, full-thickness tears, especially if chronic, produced characteristic MR findings on both T1- and T2-weighted images. We conclude that MR can be used to detect several abnormalities associated with the shoulder impingement syndrome.     

Shoulder MR arthrography: which patient group benefits most?

OBJECTIVE: We sought to compare the diagnostic accuracy of conventional MRI versus MR arthrography of the shoulder in the assessment of high-performance athletes (professional baseball players) and to compare our findings in these patients with the conventional MRI and MR arthrographic findings in an age-matched control group of nonprofessional athletes. MATERIALS AND METHODS: Conventional MRI and MR arthrographic examinations of the shoulder in 20 consecutive professional baseball players with shoulder pain were reviewed retrospectively by two musculoskeletal radiologists in consensus. These interpretations were compared with retrospective consensus interpretations of conventional MRI and MR arthrographic examinations of the shoulder obtained in a control group of 50 consecutive nonprofessional athletes with shoulder pain. MR images were assessed for full- or partial-thickness supraspinatus tendon tears, superior labral anteroposterior (SLAP) tears, and anterior or posterior labral tears. RESULTS: In the 20 consecutive professional athlete patients, two full-thickness and six partial-thickness undersurface supraspinatus tendon tears were seen on MR arthrography but not seen on conventional MRI as well as six SLAP tears, two anterior labral tears, and one posterior labral tear. Three patients had both SLAP tears and full- or partial-thickness supraspinatus tendon tears. Of 14 patients with findings on MR arthrography that were not seen on MRI, 11 had arthroscopic correlation. In all 11, arthroscopic findings confirmed findings on MR arthrography. In the group of 50 nonprofessional athlete patients, five had additional findings on MR arthrography not seen on conventional MRI: two anterior labral tears, two partial-thickness supraspinatus tendon tears, and two SLAP tears. One patient had both a partial-thickness supraspinatus tendon tear and a SLAP tear seen on MR arthrography. The five patients with additional findings on MR arthrography had arthroscopy. In all five, arthroscopic findings confirmed the findings on MR arthrography. CONCLUSION: MR arthrography is considerably more sensitive for detection of partial-thickness supraspinatus tears and labral tears than conventional MRI. MR arthrography showed injuries in addition to those seen on conventional MRI in 14 of 20 patients in the high-performance athlete group. These results suggest high-performance athletes may be a subgroup of patients for whom MR arthrography yields considerably more diagnostic information than conventional MRI.     

Rotator cuff tears: assessment with MR arthrography in 275 patients with arthroscopic correlation

We assessed the diagnostic performance of magnetic resonance (MR) arthrography in the diagnosis of articular-sided partial-thickness and full-thickness rotator cuff tears in a large symptomatic population. MR arthrograms obtained in 275 patients including a study group of 139 patients with rotator cuff tears proved by arthroscopy and a control group of 136 patients with arthroscopically intact rotator cuff tendons were reviewed in random order. MR imaging was performed on a 1.0 T system (Magnetom Expert, Siemens). MR arthrograms were analyzed by two radiologists in consensus for articular-sided partial-thickness and full-thickness tears of the supraspinatus, infraspinatus, and subscapularis tendons. At arthroscopy, 197 rotator cuff tears were diagnosed, including 105 partial-thickness (93 supraspinatus, nine infraspinatus, three subscapularis) and 92 full-thickness (43 supraspinatus, 20 infraspinatus, 29 subscapularis) tendon tears. For full-thickness tears, sensitivity, specificity, and accuracy were 96%, 99%, and 98%, respectively, and for partial tears 80%, 97%, and 95%, respectively. False negative and positive assessments in the diagnosis of articular-sided partial-thickness tears were predominantly [78% (35/45)] observed with small articular-sided (Ellman grade1) tendon tears. MR arthrography is highly accurate in the diagnosis of full-thickness rotator cuff tears and is accurate in the diagnosis of articular-sided partial-thickness tears. Limitations in the diagnosis of partial-thickness tears are mainly restricted to small articular-sided tears (Ellman grade 1) due to difficulties in differentiation between fiber tearing, tendinitis, synovitic changes, and superficial fraying at tendon margins.     

Supraspinatus tendon tears: comparison of 3D US and MR arthrography with surgical correlation

Objective

The objective of the study was to compare the diagnostic reliability of 3D US with MR arthrography in diagnosing supraspinatus tendon tears, with arthroscopic findings used as the standard.

Materials and methods

In a prospective study 50 patients who later underwent arthroscopic surgery of the rotator cuff were examined pre-operatively by 3D US with MR arthrography. The presence or absence of a full- or partial-thickness supraspinatus tendon tear and the tear size as demonstrated by each imaging and arthroscopy was recorded. The tear size was divided into three grades: small (<1 cm), medium (1-3 cm), and large (>3 cm).

Results

The arthroscopic diagnosis was a full-thickness tear in 40 patients, partial-thickness tears in 5, and intact supraspinatus tendon in 5. 3D US correctly diagnosed 35 out of 40 full-thickness tears and MR arthrography 39 out of 40 full-thickness tears. Regarding partial-thickness tears, 3D US underestimated 2 cases as no tear and overestimated 1 case as a full-thickness tear. MR arthrography underestimated 1 case as a partial-thickness tear and overestimated 2 cases as full-thickness and partial-thickness tears respectively. 3D US and MR arthrography yield a sensitivity for full-thickness tears of 87.5% and 97.5% with specificity of 90.0% and 90.0%. Based on the grading system, 3D US measurements correctly predicted the tear size of 23 (65.7%) of the 35 full-thickness tears and MR arthrography 30 (75.0%) of the 39 full-thickness tears.

Conclusion

Three-dimensional ultrasound seems to be a promising imaging modality comparable to MR arthrography for the assessment of the supraspinatus tendon tears.     

肩关节肱二头肌肌腱损伤的MRI表现

目的:探讨MRI对肩关节肱二头肌长头肌腱损伤的诊断价值。方法:收集2006年1月～2010年8月共12例肩关节肱二头肌长头肌腱损伤的病例资料,回顾性分析患者的肩关节MR扫描图像,所有病例均经肩关节手术证实。结果:①12例肱二头肌长头肌腱断裂,其中部分撕裂4例,表现为肱二头肌长头腱增粗,T2W上可见局部高信号影,肌腱连续性存在;完全撕裂8例,表现为横断面上,结节间沟内未见肱二头肌长头腱显示,斜冠状面可见撕裂肌腱近端或远端呈波浪状。肱二头肌长头肌腱半脱位1例,表现为横断面上,肱二头肌长头肌腱向内侧移位,位于肱骨小结节前方;脱位2例,表现为横断面示空置的结节间沟,肱二头肌长头腱向内侧移位、位于肩胛下肌腱前方;②肱二头肌长头腱损伤伴随腱鞘积液2例,表现为横断面上肌腱被液性高信号影所环绕;伴随肩关节腔内积液12例;③12例肱骨结节间沟宽度≥8mm;深度<3mm、结节间沟变浅3例;3例内壁角<30°;④合并肩袖损伤7例,其中冈上肌腱撕裂5例,冈下肌腱撕裂1例,肩胛下肌肌腱撕裂1例;合并喙肱韧带损伤11例。出现肩峰撞击综合征10例。结论:MRI能够准确的诊断肩关节肱二头肌长头肌腱损伤,从而有助于临床手术方案的制定。     

Full-thickness and partial-thickness supraspinatus tendon tears: value of US signs in diagnosis

PURPOSE: To determine which US signs are important in the diagnosis of a surgically identifiable supraspinatus tendon tear. MATERIALS AND METHODS: Fifty consecutive ultrasonographic (US) studies of the shoulder in patients who underwent arthroscopic follow-up were retrospectively reviewed by a musculoskeletal radiologist. US images of the supraspinatus tendon were evaluated for tendon nonvisualization, abnormal tendon echogenicity, tendon thinning, greater tuberosity cortical irregularity, cartilage interface sign, joint fluid, and subacromial-subdeltoid bursal fluid. US findings were compared with arthroscopic results. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for each US sign in the diagnosis of full-thickness tendon tear and again for any type of supraspinatus tendon tear. RESULTS: Arthroscopy revealed 21 full-thickness tears, five bursal surface partial-thickness tears, 10 articular surface partial-thickness tears, and 14 patients without tear of the supraspinatus tendon. The presence of greater tuberosity cortical irregularity and joint fluid was most important in the diagnosis of full-thickness supraspinatus tendon tear (sensitivity, 60%; specificity, 100%; positive predictive value, 100%; negative predictive value, 78%; accuracy, 84%). For diagnosis of any type of supraspinatus tendon tear (partial or full thickness), tendon nonvisualization, greater tuberosity cortical irregularity, and cartilage interface sign are most important, although a combination of signs did not improve accuracy. CONCLUSION: Secondary US signs, such as greater tuberosity cortical irregularity and joint fluid, are most valuable in the diagnosis of supraspinatus tendon tear.     

Can isotropic fast gradient echo imaging be substituted for conventional T1 weighted sequences in shoulder MR arthrography at 3 Tesla?

PURPOSE: To assess the practical utility of isotropic shoulder imaging in patients undergoing MR arthrography. Isotropic shoulder imaging can be performed in less than three minutes with use of fast gradients. MATERIALS AND METHODS: Two experienced musculoskeletal radiologists retrospectively interpreted MR images of the shoulder in 100 consecutive patients undergoing MR arthrography of the shoulder. All patients underwent MRI of the shoulder in oblique coronal, oblique sagittal, and axial planes on a 3.0-Tesla MRI system. All patients had conventional fast spin-echo T1-weighted imaging. All patients also had thin section (0.4 mm) isotropic spoiled gradient echo images performed. A total of 67 of the 100 patients underwent subsequent arthroscopy and results were compared with MR interpretations. RESULTS: There were 41 full-thickness supraspinatus tendon tears, nine partial-thickness supraspinatus tendon tears (seven articular surface and two bursal surface), 21 superior labral, 18 anterior labral, and seven posterior labral tears demonstrated by consensus retrospective reading of the 100 shoulder MR exams. There was no difference in interpretation of the isotropic images as compared to the conventionally acquired images in the oblique coronal, oblique sagittal, and axial planes. Some patients had more than one finding on each exam. A total of 67 patients went on to arthroscopy. There were 41 full-thickness supraspinatus tendon tears, nine partial-thickness supraspinatus tendon tears, 21 superior labral, 18 anterior labral, and seven posterior labral tears demonstrated on arthroscopy. All full- and partial-thickness supraspinatus tendon tears seen at arthroscopy were seen on consensus MR reading. A total of 19 out of the 21 patients with superior labral anterior posterior (SLAP) tears at arthroscopy were seen on consensus MR reading. A total of 16 of the 18 anterior labral tears and six of the seven posterior labral tears seen at arthroscopy were seen on consensus MR reading. Some of the 67 patients had more than one finding on arthroscopy. CONCLUSION: Isotropic imaging of the shoulder is practical in clinical imaging when performed with use of fast gradients on a 3-Tesla system. Isotropic imaging provides the same clinical information as conventional imaging and can be acquired in less than three minutes.     

MR versus MR arthrography in detection of supraspinatus tendon tears in patients without previous shoulder surgery

Purpose

We report the prevalence of supraspinatus tendon tears seen on MR arthrography that are not seen on conventional MR exam in the same patient population.

Materials and methods

A total of 150 consecutive conventional shoulder MR and MR arthrography exams performed on the same patients who went on to arthroscopy were reviewed retrospectively by consensus reading of two musculoskeletal radiologists. Full-thickness supraspinatus tendon tears were assessed. None of the patients had previous shoulder surgery.

Results

There were 113 full-thickness supraspinatus tendon tears seen on conventional MR exam while there were 119 full-thickness supraspinatus tendon tears seen on MR arthrography. The six additional full-thickness supraspinatus tendon tears seen on MR arthrography but not seen on conventional MR exam were confirmed at arthroscopy.

Conclusions

Some full-thickness supraspinatus tendon tears are not seen on conventional MR exam but are seen on MR arthrography. This is most likely due to fibrosis at the supraspinatus tendon tear site simulating an intact tendon on conventional MR.     

Evaluation of the symptomatic supraspinatus tendon—a comparison of ultrasound and arthroscopy

Purpose: A prospective study was undertaken to determine the accuracy of ultrasound compared with arthroscopy in the evaluation of the symptomatic supraspinatus tendon, and to identify whether ultrasound diagnosis was helpful in pre-operative planning.Methods: A total of 276 consecutive patients with shoulder impingement symptoms underwent ultrasound examination of the supraspinatus tendon. Of these patients, 41 proceeded to open or arthroscopic surgical procedure on clinical grounds, and in this group direct comparison with ultrasound findings was made.Results: There was full correlation between ultrasound and arthroscopy in the diagnosis of a normal supraspinatus tendon, full-thickness tear, tendinopathy and tendon rupture. There was some discrepancy between the two techniques. Two patients with partial thickness tear on ultrasound had a full thickness tear at arthroscopy. Ultrasound was able to identify intra-substance partial thickness tears in three patients with supraspinatus tendon said to be normal at arthroscopy. Ultrasound helped plan the surgical approach and operative time needed in cases of supraspinatus tendon rupture and full thickness tear.Conclusion: In this study ultrasound was effective in the evaluation of the symptomatic supraspinatus tendon, and was also able to diagnose intra-tendinous lesions not visible at arthroscopy.     

MR study of the intrinsic acromial angle in 74 symptomatic patients

PURPOSE: The study was undertaken to define some measurements on sagittal MR images that could provide quantitative data on the subacromial space in patients affected by nonspecific impingement syndrome and to correlate these measurements with the Bigliani classification of acromial morphology. MATERIALS AND METHODS: We retrospectively reviewed 74 shoulders in 74 patients (47 males, 27 females, age range 35-62 years) who presented with mechanical disability and pain. The patients underwent MRI using T1-weighted sagittal oblique and coronal SE sequences (TR 500 ms ,TE 12 ms) and T2-weighted FSE sequences (TR 3500, TE 25 ms) with dedicated coil. Two parameters were evaluated: the intrinsec acromial angle and the acromio-humeral distance. The measurements were made on the sagittal images at the acromion-clavicular junction and correlated to the Bigliani classification of acromial morphology. The images were evaluated by two radiologists blinded to the patients' identity, history and arthroscopic results. RESULTS: The acromial angle was measured in 72 shoulders. The values were found to correlate with the Bigliani classification. In our series, the intrinsic acromial angle (resulting from the intersection between the longitudinal acromial axis and the tangent to the acromial undersurface) ranged from 0 degrees to 17 degrees. In shoulders with rotator cuff tears the acromial angle varied between 8 degrees and 17 degrees. There were no tears for acromial angles below 8 degrees, whereas in patients with full-thickness tears the angles ranged from a minimum of 12 degrees to a maximum of 15 degrees. Acromio-humeral distance ranged from 2 mm to 10 mm; in patients with cuff tears it could not be assessed as it was close to zero in nearly all cases, whereas in cases of impingement without cuff tear it ranged from 5 mm to 10 mm. Impingement without cuff tear was detected in 31 cases, with angles ranging from 10 degrees to 17 degrees. CONCLUSIONS: Our findings demonstrate the effectiveness of the two quantitative parameters (intrinsic acromial angle and acromio-humeral distance) which are important causative factors in impingement syndrome. These parameters were found to be consistent and comparable with the Bigliani classification of acromial morphology which, although providing useful qualitative data, does not fully respond to our quantitative needs. Our study suggests that impingement syndrome is negatively correlated to acromio-humeral distance and positively correlated to intrinsic acromial angle. These parameters, which are readily detected with MRI, may be used by the radiologist and orthopaedic surgeon to screen patients with nonspecific impingement syndrome.     

Findings of the subcoracoid bursa on MR arthrography and their clinical significance

We studied visualization of the subcoracoid bursa by conducting a retrospective analysis of the MR arthrograms of 101 shoulders with surgical confirmation. MR arthrography showed the subcoracoid bursa in 28 shoulders, among which the bursa was revealed by inadvertent direct injection of contrast material into the bursa in 10 shoulders. Of the remaining 18 shoulders, 16 shoulders had rotator cuff tears, one had shoulder instability, and one had dislocation of the long head of the biceps tendon. Both the subcoracoid and subscapularis bursae are located in the subcoracoid space. The subcoracoid bursa does not communicate with the subscapularis bursa, but occasionally communicates with the subacromial-subdeltoid bursa. On MR arthrography, contrast material in the subcoracoid bursa indicates a pathologic condition such as rotator cuff tear. Careful examination of the subcoracoid bursa on MR arthrography helps to achieve better assessment of the rotator cuff.     

Association of biceps tendon tears with rotator cuff abnormalities: degree of correlation with tears of the anterior and superior portions of the rotator cuff

OBJECTIVE: This study was performed to examine the relationship and association of abnormalities seen in the long head of the biceps brachii tendon to abnormal findings in the rotator cuff. MATERIALS AND METHODS: One hundred eleven patients underwent MR imaging for shoulder pain followed by arthroscopic or open shoulder surgery from January 1997 to December 2000. Patients were identified by a retrospective search, and all consecutive patients having undergone both MR imaging and surgery were included in the patient cohort. Official MR imaging interpretations were compared with operative reports, and all findings were recorded. RESULTS: Twenty-three patients were identified with partial- or full-thickness tears of the long head of the biceps tendon. The sensitivity, specificity, and accuracy of unenhanced MR imaging of the shoulder for detecting these bicipital tears were 52%, 86%, and 79%, respectively. When a tear was present in the biceps tendon, the prevalence of supraspinatous, infraspinatus, and subscapularis tendon tears was 96.2%, 34.6%, and 47.1%, respectively. Patients with biceps tendon tears were significantly more likely to also have subscapularis tendon tears (p < 0.0001) and supraspinatous tendon tears (p < 0.008) than those patients who did not have biceps tendon tears. No significant relationship was found between the presence or absence of a biceps tendon tear and the presence or absence of a infraspinatus or teres minor tendon tear (p = 0.17). CONCLUSION: Tears of the long head of the biceps tendon have a statistically significant association with tears of the anterior and superior rotator cuff and are highly correlated with tears of the supraspinatous and subscapularis tendons. When tears of these tendons are detected, specific attention directed toward the long biceps tendon is warranted to characterize the status of this structure that provides additional stability to the shoulder joint.