الفهرس | Only 14 pages are availabe for public view |
Abstract Summary The shoulder joint is anatomically a complex joint, with different structures contributing not just to its mobility but also its stability. Glenohumeral instability is a common cause of morbidity in young patients, particularly athletes, and often requires surgical reconstruction to restore the shoulder function. The clinical spectrum of instability ranges from obvious recurrent dislocation to equivocal symptoms that may mimic other shoulder disorders. Imaging examinations are used to guide preoperative planning and the selection of appropriate therapy. The aim of this work was to assess the role of ultrasound and MR arthrography in evaluation of musclotendinous and labroligamentous lesions in patients with history of recurrent glenohumeral instability. Forty patients were included in this study 29 males and 11 females. Their age range from 17 to 44 years. All of them complaining of recurrent glenohumeral instability. All patients were clinically evaluated and then subjected to imaging modalities including ultrasound, conventional MRI and direct MR arthrography, the diagnosis was confirmed by arthroscopy. Anterior glenohumeral instability is more common than posterior glenohumeral instability and all patients (40 patients) were complaining of unilateral anterior glenohumeral instability. MR arthrography was done for all patients (40 patients), contrast material (diluted gadolinium) injected through blind technique (anterior approach) with successful intraarticular inoculation of the dye in thirty eight patients with accuracy of 95%.Regarding to labor-ligamentous lesion, Bankart lesion with avulsion of the antero-inferior aspect of the glenoid labrum with complete disruption of the scapular periosteium known as fibrous Bankart lesion was the most common labral lesions in patients with anterior glenohumeral instability (17 patients), associated adjacent glenoid rim fracture known as osseous Bankart lesion were found in 6 patients followed by Bankart variant (9 patients) in which scapular periosteium was intact (ALPSA lesion and Perths lesion 4 patients and GLAD 1 patients), SLAP (5 patients classified into 2 patients with SLAP type I and 3 patients with SLAP type II), Posterior labral tear (1 patient) and humeral avulsion of inferior glenohumeral ligament (HAGL) was present in one patient with anterior shoulder instability. Labral tears were visualized by MRA as contour deficiencies of the labrum, filling of a torn labrum with contrast material and opacification of the space between detached labrum and the gleniod surface. All labral tears were visualized by MRA except two patients with osseous Bankart lesions (misdiagnosed as fibrous Bankart and ALPSA lesions) and one patient with Perths lesion (misdiagnosed as normal labrum). While ultrasound detected 11 labral tear only as hypoechoic area at base of labrum. Hill-Sachs may be associated with shoulder instability, by MRA, Hill-Sachs lesion was present in 26 patients out of 28 patients with anterior glenohumeral instability. Hill-Sachs lesion was visualized by ultrasound in 14 patients as a triangular defect with its base facing the cutaneous plane. Rotator cuff tendon injuries were found in 7 patients in our study classified into 3 patients with complete tear and 4 patients with partial tear (as 3 patients with articular surface tear and 1 patient with intrasubstance tear). MRA detected all 7 patients with rotator cuff injuries shared in the current study. US detected 6 out of 7 patients (3 patients with complete tear and 3 patients with partial tear) with remaining one patient with partial tear misdiagnosed as intact tendon, So US and MRA were equally able to detect full thickness rotator cuff tear, however for partial tear the US appear less accurate than MRA. Conclusion; MR arthrography was an accurate technique in evaluating labral lesion compared to arthroscopy. MR arthrography was found to be superior over than conventional MRI and ultrasound in detecting labral tears. MR arthrography has added benefit of creating joint distention, which may increase the conspicuity of a subtle or non displaced labral lesion, which will be filled with high signal intensity gadolinium. Fibrous Bankart lesion being the most common labral injury, and Hill- Sachs fracture being the most common among the osseous associations. MRA and ultrasound were of near equal value in detecting rotator cuff tendon tears. |