Subacromial impingement syndrome: association of multiple magnetic resonance imaging parameters with shoulder function and pain

Introduction Shoulder pain is one of the most common complaints in orthopaedics. This study focusses on the relationship between shoulder function in subacromial impingement syndrome and imaging criteria in magnetic resonance imaging (MRI). Materials and methods This prospective clinical trial included 69 patients treated for subacromial impingement syndrome. Shoulder function (Constant Score, range of abduction, abduction force) and pain were correlated with the following MRI parameters: tendinosis of the rotator cuff, “halo-sign” around the biceps tendon, subacromial distance, critical shoulder angle, size of subacromial osteophytic spurs and maximum width of subacromial and subdeltoid bursa. Statistical analyses included Pearson’s and Spearman’s coefficients of correlation, multiple regression analysis and Student’s t-test. Results The Constant Score was correlated positively with the critical shoulder angle (r = 0.313; p = 0.009) and inversely with a “halo-sign” around the biceps tendon (rho = −0.384; p = 0.001). There was no significant correlation between spur size and shoulder function, but the size of the subacromial and subdeltoid bursae was positively correlated with the subacromial spur’s size (subacromial bursa: coronal plane: r = 0.327; p = 0.006; sagittal view: r = 0.305; p = 0.011; subdeltoid bursa coronal view: r = 0.333 p = 0.005). The width of the subdeltoid bursa in coronal plane was positively correlated with shoulder pain (r = 0.248; p = 0.004) and negatively with the range of abduction (r = −0.270; p = 0.025), as well as the mean (r = −0.332; p = 0.005) and maximum (r = −0.334; p = 0.005) abduction force. Conclusions Shoulder function and pain in subacromial impingement are best predicted by the width of the subdeltoid bursa measured in the coronal MRI plane as an indicator of bursitis as well as the presence of a “halo-sign” around the biceps tendon indicating glenohumeral joint effusion. Presence of a subacromial spur could lead to subacromial and subdeltoid bursitis, which impairs shoulder function. Shoulder function seems not to be compromised by the presence of a subacromial spur in absence of bursitis. This study was registered at the German Clinical Trials Register on 08 February 2013 (ID: DRKS00011548).

Relationship of the Shape of Subacromial Spur and Rotator Cuff Partial Thickness Tear

Background: The present study was undertaken to evaluate the relationship between location of the rotator cuff tear and shape of the subacromial spur.Methods: Totally, 80 consecutive patients who underwent arthroscopic repair for partial thickness rotator cuff tear were enrolled for the study. Bigliani’s type of the acromion, type of subacromial spur, and location of partial thickness tear of the rotator cuff were evaluated using plain X-ray and magnetic resonance imaging. We then compared the groups of no spur with spur, and heel with traction spur.Results: Of the 80 cases, 25 cases comprised the no spur group, and 55 cases comprised the spur group. There was a significant difference in type of tear (<i>p</i>=0.0004) between these two groups. Bursal side tears were significantly greater (odds ratio=6.000, <i>p</i>=0.0007) in the spur group. Subjects belonging to the spur group were further divided into heel (38 cases) and traction spur (17 cases). Comparing these two groups revealed significant differences only in the type of tear (<i>p</i>=0.0001). Furthermore, the heel spur had significantly greater bursal side tear (odds ratio=29.521, <i>p</i>=0.0005) as compared to traction spur.Conclusions: The heel spur is more associated to bursal side tear than the traction spur, whereas the traction spur associates greater to the articular side tear.