Biceps tendon dislocation: evaluation with MR imaging

The magnetic resonance (MR) images from six patients with biceps tendon dislocation--two in whom it was surgically proved and four in whom it was suspected--were retrospectively evaluated. The dislocated tendon can be identified medial to the bicipital groove, best seen on the axial and oblique coronal and sagittal images. Associated abnormalities of the biceps tendon include thickening (n = 3), high signal intensity (n = 3), and surrounding fluid (n = 4). The factors thought to contribute to dislocation can also be well seen on MR images. These include abnormal shape of the bicipital groove (n = 2), disruption of the coracohumeral ligament (n = 6), disruption (n = 4) and thinning (n = 1) of the subscapularis tendon, and supraspinatus tendon tear (n = 4). Since MR imaging is becoming the modality of choice for the evaluation of shoulder derangements, familiarity with the appearance of biceps tendon dislocation on MR images is important.     

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。     

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.     

Irreducible posterior dislocation of the shoulder: MR and CT findings

Failure to reduce an acute posterior dislocation of the shoulder is rare and is usually due to the interposition of a structure into the joint. In this paper we report the MR and CT findings of a failed reduction due to interposition of a dislocated biceps tendon between the humeral head and anterior glenoid fossa. This was associated with an avulsed subscapularis tendon with its attachment to the lesser tuberosity and a nondisplaced fracture of the humeral neck, findings which were only evident on MR.     

Humeral avulsion of the anterior shoulder stabilizing structures after anterior shoulder dislocation: demonstration by MRI and MR arthrography

 Objective. To demonstrate the MRI findings of an anterior shoulder capsular avulsion from the humerus, with or without subscapularis rupture, after anterior dislocation or severe abduction external rotation injury. Design and patients. We retrospectively reviewed the MRI and MR arthrographic examinations of seven patients who were identified at surgery with avulsion of the anterior shoulder stabilizers from the humerus. MRI was correlated with clinical history and surgical results. Results. MRI findings included: inhomogeneity or frank disruption of the anterior capsule at the humeral insertion (all), fluid intensity anterior to the shoulder (six patients), tear of the subscapularis tendon (six patients), dislocation of the biceps tendon (four patients), and a Hill-Sachs deformity (four patients). MR arthrography additionally found extravasation of contrast through the capsular defect (two patients). Conclusions. Our findings suggest that MRI is helpful for diagnosing humeral avulsion of the anterior glenohumeral capsule, especially when a tear of the subscapularis tendon insertion is present. MR arthrography may be of benefit for diagnosing capsular avulsion without associated subscapularis tendon abnormality.     

Bizepsprobleme: Ultraschall, Magnetresonanztomographie und MR-Arthrographie

Ultrasound and MR imaging are competitive imaging modalities for the diagnosis of pathologic conditions of the biceps tendon. MR imaging has substantial advantages over ultrasound because biceps tendon lesions are most commonly located in the proximal part where lesions are hidden under the acromion for ultrasound assessment. The value of MR arthrography is substantiated by the capability to assess associated diagnoses which are otherwise difficult to assess. Associated diagnoses include full- and partial thickness tears of supraspinatus and subscapularis tendons, pulley lesions, and adhesive capsulitis (frozen shoulder). Moreover, MR arthrography is the method of choice for the assessment of superior labral anterior posterior (SLAP) lesions.     

Imaging the long head of bicepstendon—a pictorial essay emphasizing magnetic resonance

Lesions of the long head of the bicepstendon (BT) are seen in association with tears of the rotator-cuff, particularly lesions of the subscapularis tendon and the rotator-interval. The frequency of positive MR-findings at the BT is approximately 25%. The pathologic alterations include complete medial luxation, subluxation and entrapment by the subscapularis tendon, tendinitis or tendovaginitis and lesions at the origin of the tendon at the superior labrum (superior labrum anterior to posterior (SLAP)--lesions). The imaging signs of BT pathology on MR include an abnormal course and position of the tendon, alterations in shape and changes in signal-intensity (SI), obliteration and thickening of the tendon-sheath. In long standing intra-articular BT rupture, neo-insertion of the tendon in the bicipital sulcus may ensue. The long BT needs to be visualized in transaxial, coronal oblique and sagittal oblique projections. Besides serving as stabilizer of the long head of biceps muscle, the BT is also an important stabilizer of the anterior joint capsule.     

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.     

Irreducible anterior dislocation of the shoulder due to soft tissue interposition of subscapularis tendon

The shoulder joint is the most unstable joint in the body and is easily dislocated. Anterior shoulder dislocation is the commonest and can be associated with glenoid and humeral fractures. Anterior shoulder dislocations are not infrequently associated with cuff tendon tears; however, anterior shoulder dislocation is easily reducible. Irreducible anterior dislocation of the glenohumeral joint is uncommon, and this could be due to bony as well as soft tissue causes. Persistent anterior dislocation due to torn subscapularis interposition in the glenohumeral joint is very rare, and only a few operative cases have been reported in the literature. We present MR features of one such case and a literature review.     

Arthroscopic biceps tenodesis with interference screw fixation: The lateral decubitus position

The tendon of the long head of biceps brachii is an important stabilizer within the glenohumeral joint. Bicepstendon pathology commonly occurs in the presence of concomitant shoulder disorders, such as subacromial impingement, and rotator cuff tears. Biceps tenodesis is indicated in the case of a partial tear (50%), an unstable biceps tendon due to an incompetent medial sling, and in the presence of a torn subscapularis. This article will describe our technique of arthroscopic biceps tenodesis with biodegradable interference screw fixation. This technique uses a uniquely designed Bio-Tenodesis screw system (Arthrex Inc., Naples, FL) and is performed with the patient in the lateral decubitus position.     

Bicipital groove dysplasia and medial dislocation of the biceps brachii tendon

The purpose of this study was to investigate the plain film finding of dysplasia of the lesser tubercle of the humerus and its relationship to medial dislocation of the tendon of the long head of the biceps brachii muscle as diagnosed by shoulder arthrography. Of 55 patients referred for arthrography of the shoulder because of undiagnosed shoulder pain, 12 demonstrated flattening of the medial wall of the bicipital tendon groove. Of these, 58% had medial dislocation of the biceps tendon, and 43% of patients with dislocation of the biceps tendon were also shown to have a tear of the rotator cuff. Since biceps tendon pathology has long been implicated in shoulder pain and weakness, assessment of the bicipital groove may provide important information in evaluating patients with potential abnormality of the biceps tendon.     

Imaging findings in the dominant shoulder of throwing athletes: comparison of radiography, arthrography, CT arthrography, and MR arthrography with arthroscopic correlation

OBJECTIVE: Conventional radiography, arthrography, CT arthrography, and MR arthrography--including use of the abduction and external rotation position--were compared, with arthroscopic correlation, to determine the spectrum of abnormalities encountered and the relative benefits of each imaging method in the evaluation of shoulder lesions occurring in 17 throwing athletes. SUBJECTS AND METHODS: Each of 36 athletes with shoulder pain aggravated by abduction and external rotation was examined in a single visit during which conventional radiography, arthrography, CT arthrography, and MR arthrography were performed. In 17 of these athletes, imaging findings were compared with those at arthroscopy. All images were independently evaluated by two groups of musculoskeletal radiologists. RESULTS: Structures found to be affected were, in decreasing order of frequency, the following: the posterosuperior labrum, supraspinatus tendon, infraspinatus tendon, humeral head, glenoid cavity and rim, acromioclavicular joint, anteroinferior capsulolabral complex, biceps tendon, and subscapularis tendon. MR arthrography without and with abduction and external rotation yielded the highest sensitivity and specificity for all lesions with the exceptions of bone sclerosis and enthesophytes (which were best seen with CT arthrography). MR arthrography with abduction and external rotation was most accurate for diagnosis of rotator cuff and anteroinferior capsulolabral complex tears. CONCLUSION: On the basis of these preliminary results, we believe that MR arthrography with abduction and external rotation should be part of the imaging evaluation of shoulder pain in throwing athletes, owing to the high sensitivity of this imaging technique.     

Normal anatomy and pathological conditions of subscapular muscle: US findings compared with surgery

PURPOSE: To compare US results with those of surgery in the assessment of the subscapularis tendon. MATERIAL AND METHODS: From January 1995 to December 1998 1500 patients underwent US of the shoulder. 12 of these patients had an injured subscapularis tendon. US results of these patients were evaluated retrospectively and compared with those of surgery. US examinations of the subscapularis tendon were performed with two US units (AU4 Idea and HDI 3000), using linear arrays 10-13 MHz transducers. The following features of the tendon were evaluated: morphology, thickness and echotexture. RESULTS: A) US findings. US showed: - chronic degenerative tendon changes with diffusely inhomogeneous echotexture (5 cases); - focal tears with small hypoechoic ill-defined areas or gross hypo-anechoic areas involving the full thickness of the tendon (4 cases); - complete tendon tear with disappearance on US of the subscapularis tendon or with severe thickening of the tendon (2 cases); - in 1 case of recent anterior dislocation of the shoulder a bulky hematoma was seen with coexisting thickening and subtotal tear of the tendon. B) Surgical findings. US findings were confirmerd at surgery in 10 of the 12 patients. In the patient with anterior dislocation of shoulder the diagnosis hematoma was confirmed, but the subscapularis tendon was undamaged. Moreover, in 1 out of the 5 patients with US diagnosis of chronic degenerative tendon changes, a small focal tear of the tendon was found at surgery. CONCLUSION: US is a first level investigation which is able to demonstrate early changes of the subscapularis tendon and nearby structures. Awareness of pitfalls might decrease the use of second level investigations such as CT arthrography and MR imaging, which on the other hand allow a better definition and assessment of the extent of the injury.     

Frozen shoulder: MR arthrographic findings

PURPOSE: To evaluate the magnetic resonance (MR) arthrographic findings in patients with frozen shoulder. MATERIALS AND METHODS: Preoperative MR arthrograms of 22 patients (six women, 16 men; mean age, 54.7 years) with frozen shoulder treated with arthroscopic capsulotomy were compared with arthrograms of 22 age- and sex-matched control subjects without frozen shoulder. The thickness of the coracohumeral ligament (CHL) and the joint capsule, as well as the volume of the axillary recess, were measured (Mann-Whitney test). Abnormalities in the CHL, subcoracoid fat, superior glenohumeral ligament, superior border of the subscapularis tendon, long biceps tendon, and subscapularis recess were analyzed in consensus by two blinded radiologists (chi(2) test). RESULTS: Patients with frozen shoulder had a significantly thickened CHL (4.1 mm vs 2.7 mm in controls) and a thickened joint capsule in the rotator cuff interval (7.1 mm vs 4.5 mm; P < .001 for both comparisons, Mann-Whitney test) but not in the axillary recess. The volume of the axillary recess was significantly smaller in patients with frozen shoulder than in control subjects (P = .03, Mann-Whitney test). Thickening of the CHL to 4 mm or more had a specificity of 95% and a sensitivity of 59% for diagnosis of frozen shoulder. Thickening of the capsule in the rotator cuff interval to 7 mm or more had a specificity of 86% and a sensitivity of 64%. Synovitis-like abnormalities at the superior border of the subscapularis tendon were significantly more common in patients with frozen shoulder than in control subjects (P = .014, chi(2) test). Complete obliteration of the fat triangle between the CHL and the coracoid process (subcoracoid triangle sign) was specific (100%) but not sensitive (32%). CONCLUSION: Thickening of the CHL and the joint capsule in the rotator cuff interval, as well as the subcoracoid triangle sign, are characteristic MR arthrographic findings in frozen shoulder.     

MR imaging of subscapularis tendon injury in the setting of anterior shoulder dislocation

Objective

To evaluate the degree and location patterns of subscapularis tendon injury in patients with prior anterior shoulder dislocation (ASD).

Material and methods

Forty-five consecutive MR shoulder examinations in patients with a history of ASD and 20 consecutive MR examinations in patients without prior dislocation were reviewed. Two readers assessed for the presence and location of tendinosis and tearing in the subscapularis tendon, which was divided into three segments: superior, middle, and inferior. The readers also documented the presence of anterior labral tears, osseous Bankart defects and Hill–Sachs lesions. Fisher’s exact tests were performed to analyze the different types of pathology and their locations.

Results

Subscapularis tendinosis, and partial thickness and full thickness tears were more common in patients with a history of ASD. Tendinosis was found in 60-64.4% of the dislocation patients compared with 40% of the non-dislocation group. When stratified by location, the middle and inferior thirds were the most commonly affected with statistical significance (p?p?Conclusion Our study suggests an association between middle and inferior subscapularis tendon pathology and prior anterior shoulder dislocation. Based on our results, careful MR assessment of the subscapularis tendon by the radiologist is indicated in the setting of ASD as injury of this structure can be symptomatic and may be amenable to treatment.     

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.     

Lesions of the reflection pulley of the long biceps tendon. MR arthrographic findings.

RATIONALE AND OBJECTIVES: The purpose of this study was to assess the diagnostic value of MR arthrography in detecting a lesion of the common insertion of the coracohumeral and the superior glenohumeral ligaments and the superior border of the subscapularis tendon (pulley lesion), which predisposes to biceps tendon subluxation and subsequent degeneration. METHODS: Parasagittal T1-weighted turbo spin-echo and axial gradient-echo (three-dimensional fast imaging with steady state-precession [FISP]) MR arthrographic images were obtained in 14 patients with surgically confirmed pulley lesions and in 10 patients with an intact pulley. Various MR arthrographic signs potentially associated with a pulley lesion were evaluated separately and independently in a blinded fashion by two radiologists. RESULTS: Abnormalities of the superior border of the subscapularis tendon on axial and parasagittal images, extra-articular contrast collection, and biceps tendon subluxation were the MR findings of a pulley lesion. The coracohumeral and superior glenohumeral ligaments were not readily visible in all patients and were not helpful in diagnosing pulley lesions in this study. The overall sensitivity for detecting a pulley lesion by MR arthrography was 86% and 93% for readers 1 and 2, with a specificity of 100% and 80% and an accuracy of 92% and 87% (kappa = 0.75). CONCLUSIONS: Based on the authors' experience, MR arthrography is valuable in detecting lesions of the reflection pulley of the long biceps tendon, although differentiation from an isolated lesion of the superior border of the subscapularis tendon may not be possible.     

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.     

MRI of the rotator interval of the shoulder

The rotator interval of the shoulder joint is located between the distal edges of the supraspinatus and subscapularis tendons and contains the insertions of the coracohumeral and superior glenohumeral ligaments. These structures form a complex pulley system that stabilizes the long head of the biceps tendon as it enters the bicipital groove of the humeral head. The rotator interval is the site of a variety of pathological processes including biceps tendon lesions, adhesive capsulitis and anterosuperior internal impingement. This article describes the anatomy, function and pathology of the rotator interval using magnetic resonance imaging (MRI).