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.     

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.     

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.     

Evaluation of Rotator Cuff Tendon Tears: Comparison of Multidetector CT Arthrography and 1.5-T MR Arthrography

Purpose: To compare the diagnostic performance of multidetector computed tomographic (CT) arthrography and 1.5-T magnetic resonance (MR) arthrography in the evaluation of rotator cuff lesions, with arthroscopic correlation. Materials and Methods: This study was approved by the institutional ethical committee, and informed consent was obtained from all patients. CT and MR arthrographic images prospectively obtained in 56 consecutive patients, following the same arthrographic procedure, were independently evaluated by two radiologists. Arthroscopy, performed within 1 month of the imaging, was used as the reference standard. Sensitivity and specificity of CT and MR arthrography were compared by using the McNemar test. Interobserver and intertechnique agreement for detecting rotator cuff lesions were measured and compared with κ and Z statistics. The Bland-Altman method was used to determine interobserver and intertechnique agreement for measuring tendon tears. For grading fatty infiltration of rotator cuff muscles, κ and Z statistics were used. Results: There was no statistically significant difference in sensitivity and specificity between CT arthrography and MR arthrography in depiction of rotator cuff lesions. The respective sensitivity and specificity of CT arthrography were 92% and 93%-97% for the supraspinatus, 100% and 77%-79% for the infraspinatus, 75%-88% and 85%-90% for the subscapularis, and 55%-65% and 100% for the biceps tendon. The respective sensitivity and specificity of MR arthrography were 96% and 83%-93% for the supraspinatus, 88%-100% and 81%-83% for the infraspinatus, 75%-88% and 90%-100% for the subscapularis, and 65%-85% and 100% for the biceps tendon. Interobserver agreement was substantial to almost perfect (κ = 0.744-0.964 for CT arthrography; κ = 0.641-0.893 for MR arthrography), and intertechnique agreement was almost perfect (κ > 0.819). CT and MR arthrography both yielded moderate interobserver and intertechnique agreement for measuring rotator cuff tears and grading muscle fatty infiltration. Conclusion: Data suggest that CT and MR arthrography have similar diagnostic performance for the evaluation of rotator cuff tendon tears. ? RSNA, 2012.     

MRI检查肩袖损伤的临床分析

目的分析肩袖损伤在MR检查时的不同扫描定位及在不同序列上的显示效果。方法对40例肩袖损伤患者行横断位T2WI,斜矢状位T1WI,斜冠状位脂肪抑制(STIR)及双斜冠状位T1WI、T2WI、脂肪抑制(STIR)扫描,分析斜冠状位与双斜冠状位图像对冈上肌、冈上肌肌腱以及肱骨干长轴的显示能力和对肩袖损伤的显示效果;以及在双斜冠状位各个序列(T1WI、T2WI、脂肪抑制STIR)中对肩袖损伤的图像显示效果按评价标准进行评价和对显示结果比较。结果 40例肩关节的斜冠状位和双斜冠状位都能全部显示冈上肌长轴,且双斜冠状位能把冈上肌、冈上肌肌腱全长及肱骨干长轴显示于一幅图像中,而斜冠状位不能;斜冠状位(STIR)显示肩袖部分撕裂和完全撕裂的分别为13例和14例,双斜冠状位(STIR)分别为22例和14例;双斜冠状位T1WI、T2WI、STIR三个序列显示肩袖结构好、较好、差的例数分别为(10、26、32;14、11、7;3、2、1)双斜冠状位T1WI、T2WI、STIR三个序列发现冈上肌肌腱、肩胛下肌肌腱、冈下肌肌腱、小圆肌肌腱、肱二头肌长头肌腱异常的例数分别为(4、21、28;2、9、15;1、6、10;0、2、4;0、1、2)。结论双斜冠状位对冈上肌、冈上肌肌腱全长及肱骨干长轴的显示能力和对肩袖损伤的显示结果均优于斜冠状位;双斜冠状位的脂肪抑制(STIR)序列对肩袖损伤的显示效果和结果均优于T2WI和T1WI。     

Clinical impact of MR arthrography of the shoulder.

PURPOSE: To evaluate the effect of MR arthrography of the shoulder on diagnostic thinking and therapeutic decisions by orthopedic shoulder surgeons. MATERIAL AND METHODS: Orthopedic surgeons completed a questionnaire before and after MR arthrography for 73 consecutive patients. The main indications were suspected rotator cuff abnormalities. The clinical diagnosis, the degree of confidence in this diagnosis, and the therapeutic decision were noted before and after MR imaging. Surgical reports were available for 34 patients. RESULTS: Thirty-four percent of the pre-MR imaging diagnoses were withdrawn after MR imaging, and new diagnoses were made after MR imaging in 13% of the cases. Confidence in the diagnosis increased significantly after MR imaging for supraspinatus and infraspinatus lesions (p<0.05). Changes of therapeutic decision after MR imaging were noted in 36 of the 73 patients (49%). In 23 patients, more invasive therapeutic procedures were initiated after MR imaging, and a more conservative treatment was implemented for 13 patients. Agreement of MR diagnoses with surgery was 94% for supraspinatus tears, 87% for infraspinatus tears, 77% for subscapularis tears, and 81% for biceps tendon lesions. Agreement of clinical diagnoses with surgery was 56%, 83%, 50%, and 64%, respectively. CONCLUSION: MR arthrography of the shoulder has a major effect on diagnostic thinking and therapeutic decisions by orthopedic shoulder surgeons.     

Contribution of full-thickness supraspinatus tendon tears to acquired subcoracoid impingement

AIM: To assess the relationship between the severity of full-thickness supraspinatus tendon tears and the development of subcoracoid impingement. MATERIALS AND METHODS: Fifty-one magnetic resonance imaging (MRI) shoulder examination reports with full-thickness supraspinatus tears were retrospectively identified and reviewed by two dedicated musculoskeletal radiologists. The appearances of the rotator cuff muscles, biceps tendon and the lesser tubercle were recorded. The acromio-humeral distance and the axial coraco-humeral distance were measured. The data were recorded and analysed electronically. RESULTS: The kappa values for inter-observer agreement were: 0.91 for acromio-humeral distance and 0.85 for coraco-humeral distance measurements. Twenty-six patients had significant retraction of the supraspinatus tendon, 85% (22 cases) of this group had imaging evidence of tear or tendonopathy of the subscapularis tendon. Twenty-five patients had no significant retraction of the supraspinatus, 56% (14 cases) of this group had imaging evidence of a subscapularis tear or tendonopathy. The acromio-humeral distance was significantly less in patients with supraspinatus tears and retraction (p<0.05). The subscapularis tendon was significantly more likely to be abnormal if the supraspinatus was retracted than if no retraction was present (p<0.05). There were no significant differences in coraco-humeral distances between the groups. CONCLUSION: Subscapularis tendon signal and structural changes are frequently associated with full-thickness supraspinatus tendon tears, particularly if the supraspinatus is significantly retracted. In this static MRI series, the data do not support the occurrence of classical subcoracoid impingement as an aetiology; however, they may support the possibility of a dynamic mechanism, to which future studies could be directed.     

Shoulder after rotator cuff repair: MR imaging findings in asymptomatic individuals--initial experience

PURPOSE: To assess the magnetic resonance (MR) imaging appearance of the successfully repaired rotator cuff in an asymptomatic population. MATERIALS AND METHODS: Fifteen subjects who had undergone clinically successful rotator cuff repair were included in the study. All underwent functional testing of the affected shoulder and had good to excellent scores on the Constant scale. Standard MR imaging sequences were performed at 1.5 T, including oblique coronal fast spin-echo T2-weighted MR imaging with fat saturation. RESULTS: Three (10%) of 30 supraspinatus and infraspinatus tendons had normal signal intensity, and 16 (53%) had mildly increased signal intensity on fast spin-echo T2-weighted fat-saturated images, compatible with tendonitis or tendinosis. Three partial and four complete tears of the supraspinatus tendon and two partial and two complete tears of the infraspinatus tendon were seen. Other findings included subacromial-subdeltoid effusion (10 subjects), joint effusions (five subjects), and bone marrow edema (six subjects). CONCLUSION: Postoperative signal intensity changes consistent with tendonitis or tendinosis were common, and clinically "silent" partial and complete rotator cuff tears were seen. Such postoperative MR imaging findings should be interpreted with caution, and meticulous correlation with symptoms and clinical results is recommended.     

Surgically repaired massive rotator cuff tears: MRI of tendon integrity, muscle fatty degeneration, and muscle atrophy correlated with intraoperative and clinical findings

OBJECTIVE: Our goal in this study was to evaluate by means of MRI the clinical significance of tendon integrity, muscle fatty degeneration, and muscle atrophy in surgically repaired massive rotator cuff tears and to correlate these and other prognostic factors with intraoperative and clinical findings. MATERIALS AND METHODS: Twenty-eight surgically proven massive rotator cuff tears were retrospectively included in the study. Twenty-two patients underwent complete repair, and six patients underwent partial repair. Preoperative and postoperative clinical assessment was performed by using the University of California at Los Angeles score. Preoperative and postoperative MRI studies were evaluated for the presence and extent of rotator cuff tear and for the degree of fatty degeneration and atrophy of the rotator cuff muscles. RESULTS: At a mean 44.4 months' follow-up, 20 patients (71.4%) had a favorable result. A total of 25 patients (89.2%) showed postoperative full-thickness rotator cuff tear, 19 of which were reruptures. A sagittal preoperative rotator cuff tear of less than or equal to 34 mm showed a specificity of 100% for predicting a favorable outcome. A coronal postoperative rotator cuff tear of less than or equal to 34 mm showed a specificity of 85.7% and a positive predictive value of 92.9% for predicting a favorable outcome. A postoperative fatty degeneration of infraspinatus muscle less than or equal to 2 had a specificity of 87.5% and a positive predictive value of 90.9% for predicting a favorable outcome. CONCLUSION: Open repair of massive rotator cuff tears may reach a favorable outcome in a significant proportion of patients, despite a high rate of recurrent or residual tears. Oblique coronal sizes of the recurrent or residual tear of less than or equal to 34 mm and postoperative fatty degenerations of infraspinatus muscle of less than or equal to 2 may allow a favorable outcome.     

Rim-rent tear of the rotator cuff: a common and easily overlooked partial tear

OBJECTIVE: The purpose of this study was to determine the incidence of rim-rent rotator cuff tears in a population of patients referred for shoulder MRI and to determine the sensitivity of MRI for the detection of these tears. CONCLUSION: Rim-rent tears are a common type of partial-thickness rotator cuff tear, much more commonly present than has been previously reported. In particular, infraspinatus rim-rent tears are more common than previously believed. Rim-rent tears of the infraspinatus tendon and those involving the anterior-most fibers of the supraspinatus tendon are commonly overlooked on MRI, possibly because of failure to appreciate the high incidence of these types of tears and failure to inspect the anterior-most fibers of the rotator cuff.     

Imaging of degenerative and posttraumatic disease in the shoulder joint with ultrasound

This article reviews the examination technique of shoulder ultrasound, normal and abnormal ultrasound findings in acute (posttraumatic) and chronic (degenerative) lesions. Moreover, it reviews the effectiveness of ultrasound in relation to magnetic resonance (MR) imaging. Most authors report that full-thickness tears of the supraspinatus can reliably be diagnosed by ultrasound. However, the simple diagnosis of a full-thickness rotator cuff tear is no longer sufficient for surgical management. The precise localization and size of rotator cuff tears as well as the extent of muscle degeneration is important for surgical planning. For this aspect and for partial-thickness tears of the supraspinatus, for subscapularis lesions as well as for lesions of the long biceps tendons there is no consensus regarding the diagnostic value of ultrasound. To the present, ultrasound (contrary to MR imaging) has failed to demonstrate that it consistently influences the clinician's degree of confidence in the clinical diagnosis or the treatment plan. Therefore, some orthopedic surgeons prefer MR imaging to ultrasound in the evaluation of rotator cuff tears and other abnormalities of the glenohumeral joint. Moreover, MR imaging, especially when combined with arthrography, represents a one-step investigation, which not only allows for assessment of rotator cuff lesion but also of lesions of the labrum (Bankart lesions, SLAP lesions), the joint capsule and the biceps tendon. It also demonstrates muscle atrophy, which represents an important predictor of surgical outcome in rotator cuff repair.     

Infraspinatus muscle atrophy: implications?

PURPOSE: To evaluate associated findings in patients who exhibited atrophy of infraspinatus muscle at magnetic resonance (MR) examination of their shoulders to clarify implications of this abnormality. MATERIALS AND METHODS: With an electronic database search, cases of advanced infraspinatus muscle atrophy in patients who underwent MR imaging during a 1-year period for evaluation of shoulder pain or dysfunction were identified. The analysis was restricted to cases interpreted by one reader who applied a standardized method of reporting. Associated MR imaging findings in these cases were tabulated. RESULTS: Advanced infraspinatus muscle atrophy was encountered in 51 (4.3%) of 1,191 MR examinations of the shoulder. Tears of the infraspinatus tendon were present in only 27 (53%) of 51 cases. In 46 (90%) of 51 cases, a full-thickness tear was present in the anterior portion of the rotator cuff. In 10 (20%) of 51 cases with infraspinatus muscle atrophy, cuff muscle atrophy was confined to the infraspinatus muscle. Cuff muscle atrophy was isolated to the infraspinatus muscle in four (17%) of 24 cases in which atrophy of the infraspinatus muscle was present despite an intact tendon. In none of the 51 cases was there a mass in the suprascapular or sphenoglenoid notch. CONCLUSION: Infraspinatus muscle atrophy typically occurs with tendon tears in the anterior aspect of the rotator cuff. Concomitant atrophy in the supraspinatus muscle often is present, but infraspinatus muscle atrophy can occur in isolation, and this finding does not imply that the infraspinatus tendon is ruptured.     

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。     

Partial tears of the subscapularis tendon found during arthroscopic procedures on the shoulder: a statistical analysis of sixty cases

BACKGROUND: Prevalence and clinical significance of partial tears of the subscapularis tendon have not been widely studied. PURPOSE: To determine prevalence of and clinical factors associated with partial tears of the subscapularis tendon at arthroscopy. STUDY DESIGN: Case control study. METHODS: During arthroscopic procedures on 314 consecutive shoulders, the arthroscopically visible portion of the subscapularis tendon was probed. Patients with and without partial tears were compared for prospectively identified variables. RESULTS: Partial tears were found in 60 of the 314 patients (19%). Increasing age and dominant arm involvement were significant variables for partial tears. Significantly associated factors included supraspinatus tendon tears (54 of 60; 90%), rotator cuff disease (44 of 60, 73%), and posterosuperior labral fraying (34 of 47, 72%). Increasing age, dominant arm involvement, and coexisting infraspinatus tendon tears were strong independent risk factors for partial tears. CONCLUSION: Partial tears of the subscapularis tendon are not uncommon findings during shoulder arthroscopic procedures and are associated with extensive rotator cuff disease. They do not appear to be associated with glenohumeral instability, but a possible association with atypical forms of instability (subclinical or superior instability) cannot be excluded by this study. The absence of a significant association between the lesion and specific subjective symptoms or physical findings suggests that caution should be taken when attributing a specific symptom to this condition.     

Repair of tears of the subscapularis tendon

Tears of the subscapularis are much less common than tears of the supraspinatus and infraspinatus. Subscapularislesions are usually traumatic in etiology and occur in younger patients. These lesions can be complete or limited to the superior insertion of the subscapularis, and they may be isolated or occur with other rotator cuff lesions. In most instances, treatment of subscapularis tears is surgical. In this article, we present the clinical and radiographic findings, discuss operative indications, and illustrate our preferred surgical technique for tears of the subscapularis tendon.     

Anterior stability of the glenohumeral joint. A dynamic model

This study defines the interaction of the rotator cuff musculature and the glenohumeral ligaments in providing anterior stability to the glenohumeral joint. Eight cadaveric shoulders were studied using a testing frame that individually simulated the forces of the subscapularis, the supraspinatus, and the infraspinatus/teres minor musculature. The application of these forces abducted the humerus to approximately 90 degrees. The cocking phase of throwing was then simulated through the use of an Instron. With random variation of the rotator cuff forces, we investigated the effects that each force had on the rotation of the humerus and the strain of the inferior glenohumeral ligament. Our results demonstrate that the infraspinatus/teres minor muscle group was the most effective in controlling external rotation of the humerus and in reducing ligamentous strain. These observations are pertinent in the treatment of anterior instability syndromes of the shoulder.     

Diagnosis of tears in rotator-cuff-injuries

Pathology of the rotator cuff is the cause of most common problems at the shoulder joint. Acute injuries are not as frequent as chronic cuff disease, but often they aggravate inflammatory or degenerative tendon alterations, even if they are of minor severity. Traumatic rotator cuff tears predominantly affect the supraspinatus tendon or the rotator interval. The subscapularis tendon is involved in anterior dislocations of the glenohumeral joint or in direct trauma. Plain film radiography still remains the base of all further imaging studies. If only full-thickness tears must be ruled out, double-contrast arthrography and ultrasound are acceptable imaging modalities. However, the former has a drawback in being invasive and does not detect partial tears at the bursal site of the cuff or rotator cuff tendinopathy, whereas the latter heavily depends on the experience of the radiologist and is restricted to the rotator cuff. Nowadays the most comprehensive imaging method is magnetic resonance (MR) imaging. MR imaging enables the detection or exclusion of complete rotator cuff tears with a reasonable accuracy and is also suitable to diagnose further pathologies of the shoulder joint. MR arthrography is valuable in the detection of subtle anatomic details and further improves the differentiation of rotator cuff diseases. Although in comparison MR imaging is still the most expensive imaging method, its high negative predictive value for the diagnosis of complete rotator cuff tears and its reliability evaluating different shoulder joint pathologies make it the preferred imaging modality.     

Diagnostic performance of MR arthrography after rotator cuff repair

OBJECTIVE: The objective of this study was to investigate the diagnostic performance of MR arthrography after rotator cuff repair. MATERIALS AND METHODS: MR arthrographic examinations of the shoulder performed after rotator cuff repair and before revision surgery were retrospectively analyzed in 48 patients (31 males, 17 females; mean age, 50.3 years; age range, 17-69 years). Full-thickness and partial-thickness defects of the supraspinatus, infraspinatus, and subscapularis tendons were diagnosed independently by two radiologists. Revision surgery served as the standard of reference. RESULTS: Observer 1 correctly recognized five of eight intact supraspinatus tendons, 10 of 19 partial-thickness defects, and 19 of 21 full-thickness defects. For observer 2, the numbers were three of eight, eight of 19, and 18 of 21. The corresponding numbers for the infraspinatus tendon for observer 1 were 28 of 31, 0 of three, and 14 of 14 tendons. For observer 2, they were 28 of 31, two of three, and 11 of 14. For the subscapularis tendon, observer 1 made the correct diagnosis in 18 of 31, five of six, and nine of 11 tendons. The results for observer 2 were 26 of 31, one of six, and 10 of 11 tendons. Interobserver agreement (weighted kappa) was 0.47 for the supraspinatus, 0.64 for the infraspinatus, and 0.20 for the subscapularis tendons, respectively. CONCLUSION: Postoperative full-thickness defects of the rotator cuff are reliably diagnosed with MR arthrography. The diagnostic performance for partial-thickness defects is only moderate.     

Magnetic resonance imaging evaluation of muscle usage associated with three exercises for rotator cuff rehabilitation.

PURPOSE: Methods of determining muscle usage for exercises involving rotator cuff muscles are limited. Therefore, this investigation used magnetic resonance imaging (MRI) to evaluate the effect of three different exercises used for rehabilitation of the rotator cuff. METHODS: Five normal volunteer subjects (3 men, 2 women, mean age 31.4 yr) were studied. The exercises were scaption with internal rotation (SIR), military press (MP), and side-lying 45 degrees abduction (SLA). MR imaging was performed immediately before and after exercise using a "fast" spin echo STIR sequence and oblique coronal plane imaging. Changes in signal intensity pre- and post-exercise were measured at comparable section locations for the MR images of the supraspinatus, infraspinatus, teres minor, subscapularis, deltoid, and trapezius. RESULTS: The SLA showed the greatest increase in signal intensity in all the muscles (percent change, P < 0.01) except for the trapezius, which was used more by the MP and SIR. None of the exercises activated the teres minor (percent change, P = not significant). CONCLUSION: These findings have important implications in efficacy of physical rehabilitation of the rotator cuff and avoidance of subacromial impingement exercise motions.