De Wilde Lieven, Sys Gwen, Julien Yann, Van Ovost Edwin, Poffyn Bart, Trouilloud Pierre
University Hospital of Gent, Belgium.
Acta Orthop Belg. 2003 Dec;69(6):495-500.
The authors present two series of six and seven patients respectively, with a tumour of the proximal humerus, who were treated at two different institutions with a Delta type inverted shoulder prosthesis (DePuy International Ltd) after a Malawer type Ia or Ib resection. The rationale of using an inverted shoulder prosthesis is the aim to improve the functional outcome in rotator cuff deficient shoulders. This type of prosthesis medializes and lowers the centre of rotation, lengthens the lever arm of the deltoid muscle and improves its function. At one institution the resected part of the humerus was re-implanted after extracorporeal irradiation. It was fixed intramedullarly by cementation of the humeral prosthetic component to facilitate restoration of humeral height. This graft allowed reinsertion of muscles (deltoid, pectoralis, biceps) thus improving power generation postoperatively. The largest glenosphere, size 42, was routinely used to reconstruct the glenoid; this theoretically improves the functional outcome (increased external rotation) and stability. At the other institution no graft augmentation was used except in one patient. The height of the humeral prosthetic component was assessed after resection of the tumour by measurement of the resected part. The prosthetic stem was fitted in the remaining part of the humeral diaphysis, in three cases by cementation and in three cases by press-fit (hydroxyapatite coating). Muscle balance was appreciated intra-operatively. Stability of the prosthesis was directly related to the level of resection. Both techniques resulted in a minimum active abduction of 60 degrees, reaching 90 degrees or more in most patients. When compared to other results in the literature, this is a major functional improvement. The mean adjusted postoperative Constant score was 72.5% (range: 30-90%), and the mean MSTS score was 75.8% (range 36.7-96.7%).
作者分别展示了两组病例，一组6例，另一组7例，均为近端肱骨肿瘤患者，在两家不同机构接受治疗，于Malawer Ia型或Ib型切除术后使用Delta型反肩假体（DePuy国际有限公司）。使用反肩假体的基本原理是旨在改善肩袖功能不全肩部的功能结果。这种类型的假体将旋转中心内移并降低，延长三角肌的力臂并改善其功能。在一家机构，肱骨切除部分在体外照射后重新植入。通过肱骨假体部件的骨水泥固定将其髓内固定，以促进肱骨高度的恢复。这种移植允许肌肉（三角肌、胸大肌、肱二头肌）重新附着，从而改善术后的力量产生。常规使用最大尺寸为42的关节盂球窝来重建关节盂；从理论上讲，这可改善功能结果（增加外旋）和稳定性。在另一家机构，除1例患者外未使用移植增强术。肿瘤切除后通过测量切除部分来评估肱骨假体部件的高度。假体柄安装在肱骨干的剩余部分，3例采用骨水泥固定，3例采用压配（羟基磷灰石涂层）。术中评估肌肉平衡。假体的稳定性与切除水平直接相关。两种技术均导致最小主动外展为60度，大多数患者达到90度或更高。与文献中的其他结果相比，这是一项重大的功能改善。术后平均调整后的Constant评分是72.5%（范围：30 - 90%），平均MSTS评分为75.8%（范围36.7 - 96.7%）。
