外傷性肩関節前方不安定症の病態
－関節包断裂とHAGL病変－

抄録

The purpose of this study was to analyze the relevant factors in recurrent anterior glenohumeral instability with an anteroinferior capsular lesion.
From 1998 to 2005, 294 shoulders with anterior glenohumeral instability underwent arthroscopic stabilization in our institution. A capsular tear was observed in 33 shoulders, which was 15%, and an HAGL lesion was observed in 11 shoulders, which was 4% among the 294 shoulders. The subjects consisted of 44 patients, 22 males and 22 females, with an average age at the time of surgery 32.3 years old. The findings of a preoperative 3-dimentionally reconstructed computed tomography were also assessed. All the patient underwent an-arthroscopic repair.
We classified the capsular lesion through our arthroscopic investigation into 4 types: TypeI: the capsular tear was located only on the glenoid-side, Type II: the capsular tear was spread from the glenoid-side to the humeral side, Type III: HAGL lesion, Type IV: the capsular tear with an HAGL lesion. There were 19 TypeI, 14 TypeII, 8 TypeIII, and 3 TypeIV shoulders. The majority of the type II capsular tears were located between the MGHL and the AIGHL, parallel to the superior border of the AIGHL. We believe that this separation between the MGHL and the AIGHL caused a functional deficit of the anterior capsular mechanism. Furthermore all types of capsular lesions could be an essential lesion causing a recurrent anterior dislocation. However, A TypeI capsular lesion might sometimes be a secondary lesion. The frequently associated bony Bankart lesion or subscapralis tears in older patients seemed to be more responsible for this instability. On the other hand, the TypeII and TypeIII capsular lesion should be an essential lesion causing recurrent anterior dislocation. Because the morphology of the glenoid rim were less affected. We can expect an excellent outcome, through precise anatomical repair of these capsular lesions along with a Bankart lesion.