Research of relation between rotator cuff tears and glenohumeral joint compatibility

In classical litterateur knowledge ; Rotator cuff tears are arised from vasculer, mechanic, anatomic, degenerative and traumatic disorders.In our study, we searched the relation between Rotator cuff tears and glenohumeral joint compatibility. We studied on patients with Rotator cuff tear and tried to find out that if glenohumeral joint incompatibility is a reason for glenohumeral joint instability and we aimed to prove it by two different measurement method.There isn?t any sufficient study which researches the relation between static and dynamic stabilizers of glenohumeral joint.In our study, we evaluated the patients shoulder MRI ; who were examined in AIBU Medical Faculty, Orthopaedy and Traumatology policlinic between 01/01/2010 and 31/12/2011; who have decreased ROM or shoulder pain. Totally we chose 59 patients for our study and they are divided in 3 groups; first group consist of 20 patients with intact Rotator cuff (group 1, n:20), second group consist of 19 patients with partial thickness Rotator cuff (at supraspinatus) tears (group 2, n:19), third one consist of 20 patients with full thickness Rotator cuff tears (group 3, n:20).We evaluated glenohumeral joint compatibility on MRI of all patients by using geometric morphometry and linear measurement methods. For geometric morphometric measurements we chose oblic coronal plane shoulder images of 59 patient?s right shoulder MRI. These images were evaluated in Tps program. We identified 5 referance points on these images. Then txt files that show coordinates of these points were created. For linear measurement method we chose the same images of 59 patient?s right soulder MRI. Two different linear measurement were made by linear method. At first measurment the distance between superior and inferior ends of cavitas glenoidalis concav surface were measured by program(G value). At second measurement süperior and inferior ends of convex caput humeri was identified as collum anatomicum length and measured (H value). So G/H ratios were calculated. We used same referance points in geometric morphometric and linear measurements.Manova analysis of Geometric morphometric measurement results showed that there was no significant difference between three groups (p>0,05). At dually comparision test we found difference between group 1 and group 2.Statistical analiysis of linear measurement results showed that there was no difference between 3 groups about G value and H value. At the evaluation for G/H ratio (glenohumeral joint compatibility), there was no significant difference between group 1 and group 3 (p>0,05), group 2 and group 3 , but there was difference between group 1 and group 2 (P<0,05). G/H ratio of group 2 was higher than G/H ratio of group 1. We saw that this difference was based on the difference between average glenoid diameter of group 2 and group 1 (average glenoid diameter of group 2 > average diameter of group 1 ). According to these results we commentated that there wasn?t any instability at group 2 patients, cause classical litterateur knowledge says decrease of glenohumeral index results in glenohumeral instability.In our study we evaluated glenohumeral compatibility by two different measurement methods. Our results showed that 3 group?s G/H results are similar to normal values of litterateur knowledge. So our study shows that there is no difference about glenohumeral joint compatibility between patients with rotator cuff tears and healty population (intact RC).We think that researching of relation between rotator cuff tears and static stabilizers; like labrum and capsuloligamentous structures other than shoulder joint anatomy; should be important to find out the relation between instabile shoulders and rotator cuff tears.