الفهرس | Only 14 pages are availabe for public view |
Abstract Structurally the shoulder joint is a weak joint due to disparity of articulating surface area between small and shallow glenoid cavity in comparison to head of humerus Shoulder pain is the third most common musculoskeletal complaint in the general population Subacromial impingement is the most frequent cause of shoulder pain, accounting for up to 60% of all shoulder complaints The term shoulder impingement was first introduced by Neer 1972 and referred to compression of rotator cuff, subacromial bursa and biceps tendon against the undersurface of the acromion & coracoacromial ligament , that exaggerates on elevation of the arm. it is often difficult to diagnose because the clinical presentation may be confusing and clinical tests lack specificity . There are many etiological factors of rotator cuff impingement , including anatomical , mechanical, vascular, degenerative & trumatic factors. Keeping in consideration that, in the majority of cases , the process of impingement is multifactorial, and the key factor in any case depends on the individual circumstances In the past, several imaging modalities were used ranging from conventional radiography, arthrography to computerized axial arthrography. Recently, various imaging modalities are now available including ultrasonography, CT arthrography, conventional MRI and MR arthrography. The most common radiological findings in such cases are abnormal acomion shape, acromio-calvicular osteoarthritis, subacromial bursitis, rotator cuff abnormalities (including tendinosis, partial-thickness tears & full-thickness tears), reduced subacromial tunnel & biceps tenosynovitis. MRI was considered to be the examination of choice for the evaluation of the cases with subacromial impigement , but it can only provide a static evaluation of the shoulder joint and indirectly suggesting the diagnosis of subacromial impingement, in addition to its high cost , long examination time and subjective limitations, as in patients having pace-makers or claustrophobics. MR in cases of subacromial impingement can precisely detect: Narrowing in the subacromial tunnel Different types of rotator cuff tears. Rotator cuff tendinosis Fluid in the joint , in the subacromial and subdeltoid bursa, Acromio-clavicular joint degenerative changes and its impact on the rotator cuff tendons. Biceps teno-synovitis. The shoulder joint is anatomically complex, where its stability depends on a combination of osseous structures and soft tissue structures surrounding the shoulder known as the labral ligamentous complex, joint capsule, muscles and tendons where they are acting as dynamic as well as static stabilizers preventing the joint from exceeding the optimized range of motion. Glenohumeral instability remains a very complex and sometimes challenging diagnostic problem. There are potential lesions of the capsule and Labroligamentous structures that can occur in association with shoulder instability, and the clinical history and physical findings are not always sufficient to make accurate diagnosis. Antero-inferior dislocation is the most common frequent cause of shoulder instability. The aim of this work is to evaluate the role of magnetic resonance imaging in diagnosing the different lesions that cause shoulder joint pain. This study included 20 patients; clinically presented with shoulder pain whether traumatic or atraumatic associated with limitation of movement, dislocation and/or dislocation. Most of the patients were examined with conventional MRI and some of them were subjected to MR arthrography. Conventional MR imaging, which allows direct visualization of major anatomic structures, had been traditionally used in the examination of patients with shoulder instability, though it has been pointed out that accurate interpretation of glenohumeral joint structures is beset with pitfalls. To improve the evaluation of smaller intra-articular structures such as the glenoid labrum and glenohumeral ligaments, MR arthrography is increasingly recognized as the examination of choice in glenohumeral instability providing demarcation of complex anatomic structures of the joint and demonstration of subtle abnormalities, along Summary 168 with excellent delineation of associated intra-articular lesions. MR arthrography extends the capabilities of conventional MR imaging because contrast solution distends the joint capsule, outlines intraarticular structures, and leaks into abnormal areas. In our study, MR arthrography has good role in diagnosis of labral tears in addition to imaging capsuloligamentous, cartilaginous injuries as well as small partial or complete tears of the rotator cuff tendons. In conclusion, our results recommend that MRI should be increasingly used, especially when there is any uncertainty, or when the issue of labral or capsular tear is not obvious from the clinical investigation. Further MR arthrography is, however, needed in order to be able to evaluate the joint capsule itself, and the size of the ligamentlabral injury. |