Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Forchstrasse 340, CH 8008, Zurich, Switzerland.
J Orthop Surg Res. 2019 Dec 12;14(1):435. doi: 10.1186/s13018-019-1486-1.
Portal placement is a key factor for the success of arthroscopic procedures, particularly in rotator cuff repair. We hypothesize that the acromial anatomy may strongly determine the position of the shoulder bony landmarks and limit the surgeon's freedom to position the arthroscopic approaches in direction towards the acromion. The purpose of this study was to analyze the relation between different acromial shapes and the freedom of movement of arthroscopic instruments relative to the rotator cuff from standardized arthroscopic portals in a laboratory study on 3D shoulder models.
3D models of shoulders with a broad range of different acromial shapes were printed using CT and MRI scans. Angles from the portals to defined points on the rotator cuff and the supraglenoid tubercle were measured. In conventional radiographs, the critical shoulder angle, the scapular body acromial angle, and the glenoid acromial angle were measured and compared with the measured angles to the rotator cuff.
There was a large variation of angles of approach of instruments to the rotator cuff between the seven shoulders for each portal. From the joint line portal and the posterior edge portal, the biggest angles were measured to the posterior cuff. From the intermediate portal, the angles were largest to the intermediate rotator cuff and from the anterior portals to the anterior cuff. To the supraglenoid tubercle, best access was from anterior. For all portals, there was a big correlation between the glenoid acromial angle and the scapular body acromial angle with the angles of approach to the tendon and especially to the supraglenoid tubercle.
The access to the rotator cuff from almost every portal is influenced by the acromial shape. As hypothesized, a small (small GAA) and flat (big SBAA) acromion provide an easier approach to the rotator cuff from almost every portal. Therefore, it may severely influence the instruments maneuverability.
关节镜手术中， 关节盂的位置是成功的关键因素， 特别是在肩袖修复术中。我们假设肩峰解剖结构可能会强烈影响肩部骨性标志的位置，并限制外科医生将关节镜入路定位在朝向肩峰的方向。本研究的目的是在 3D 肩部模型的实验室研究中，分析不同肩峰形状与关节镜器械相对于肩袖的运动自由度之间的关系，这些模型是通过 CT 和 MRI 扫描打印的。从关节镜入路到肩袖和肩峰上突的定义点测量角度。在常规 X 光片中，测量关键肩角、肩胛骨体肩峰角和关节盂肩峰角，并与测量到肩袖的角度进行比较。
使用 CT 和 MRI 扫描打印出具有广泛不同肩峰形状的肩部 3D 模型。从关节镜入路到肩袖和肩峰上突的定义点测量角度。在常规 X 光片中，测量关键肩角、肩胛骨体肩峰角和关节盂肩峰角，并与测量到肩袖的角度进行比较。
对于每个关节镜入路，七个肩部之间的器械进入肩袖的角度有很大差异。从关节线入路和后缘入路测量到的后肩袖角度最大。从中间接入路测量到的中间肩袖角度最大，从前入路测量到的前肩袖角度最大。对于前上突，最佳进入路径是从前入路。对于所有关节镜入路，关节盂肩峰角和肩胛骨体肩峰角与肌腱进入角度（特别是与肩峰上突的进入角度）有很大相关性。
几乎每个关节镜入路都受到肩峰形状的影响。正如假设的那样，小的（小 GAA）和扁平的（大 SBAA）肩峰为从几乎每个入路进入肩袖提供了更容易的途径。因此，它可能严重影响器械的可操作性。
