Abstract
Introduction
Modern prostheses of the 3rd and 4th generation facilitate a precise adjustment to various humeral anatomies. This provides major advantages regarding soft tissue balancing and the reconstruction of the rotational center. Thus, high expectations are linked to the use of modern shoulder prostheses compared to conventional designs.
Methods
Out of a prospective multicenter study, 108 cases (72 females, 36 males) were reviewed. All patients were treated with the same type of double eccentric shoulder prosthesis. The mean age at surgery was 71.5 years (range, 44.6 to 97.3). The Constant Score (CS), ASES Score, X-rays and complications were evaluated at 3, 6, 12 and 24 months as well as 4, 7 and 10 years follow-up.
Results
At a mean follow-up time of 93.3 months, the mean CS improved from preoperative 25.6 (±8.8) to 63.8 (±19.1) points at 7 years. In the same period, the mean ASES Score improved from 24.5 (±12.5) to 79.6 (±19.1). Pain according to the CS was rated preoperatively as high (mean 1.8 points). After 7 years patients suffered from mild to no pain (mean 12.0 points). A total of 7 prostheses were revised, leading to an overall survival rate of 91.5% at 10 years. In 4 cases secondary glenoid erosion was the reason for revision.
Conclusion
The clinical results of the investigated prosthesis system are convincing and comparable to other modern shaft prostheses. To achieve an anatomical reconstruction of the rotational center of the humeral head, the use of a double eccentric shoulder prosthesis is recommended
