Strategien beim Endoprothesenwechsel der Schulter

Abstract

The increasing number of primary shoulder arthroplasty operations is correlated to an increasing revision rate of up to 11.2% for anatomical shoulder arthroplasty and 13.4% for reverse shoulder arthroplasty. To reduce the risk of implant revision the surgeon has to take the possibility of late complications into account for the index operation and to choose a modular implant system. Indications for revision arthroplasty are secondary glenoid wear, aseptic loosening, infections, rotator cuff deficiency, instability, implant malpositioning, mechanical complications and periprosthetic fractures. Due to the high rate of humeral fractures during revision surgery of anatomical stemmed implants (12%) and reverse implants (30%) osteotomy of the humerus is of particular importance. Osteotomy of the humeral shaft with a distal window or transhumeral shaft osteotomy as described by Gohlke can be used. The most demanding step during implantation of the revision implant is the accurate reconstruction of the prosthetic height because the stability, strength of the deltoid muscle and in unfavourable situations the degree of stiffness in the glenohumeral joint all depend on the prosthetic height. The result of anatomical glenoid revision surgery totally depends on the bony defect. Revision glenoid components showed better results compared to glenoid reconstruction using a corticocancellous bone graft but resulted in a higher rate of secondary loosening of the glenoid implant. Cementless glenoid revision implants seem to achieve a higher stability of bony fixation than cemented implants. Due to a better form closure with the reverse humeral implant and a mechanically more favorable loading of the glenoid bone stock, the glenosphere should be implanted with an inferior tilt in revision surgery.