Conversion of Hemiarthroplasty to Reverse Shoulder Arthroplasty with Humeral Stem Retention

The purpose of this study is to evaluate the mid-term clinical results of an ongoing case series on conversion reverse shoulder arthroplasty (RSA) with a modular prosthesis system. We included 17 elderly patients revised for failed hemiarthroplasty after proximal humeral fracture, of which 13 were converted using a modular reverse shoulder prosthesis. Four could not be converted due to overstuffing. For the conversion RSA, we determined the Constant score, American Shoulder and Elbow Surgeons Shoulder Score, visual analogue scale for pain and satisfaction, and range of motion preoperatively, at one year, and at the last follow-up. All measured clinical outcomes improved significantly at both follow-up time points (p < 0.05). The mean duration of surgery was 118.4 min (range: 80.0 to 140.0 min). We observed complications in three patients; these included one late infection and two aseptic stem loosenings. Modular shoulder arthroplasty is a suitable procedure for conversion RSA in elderly patients. All measured postoperative clinical outcomes improved significantly, the complication rate was acceptable, and no prosthesis-related complications occurred. Conversion RSA, although not feasible in every case, is a viable treatment option in the elderly, which can provide successful mid-term results

Differences in reconstruction of the anatomy with modern adjustable compared to second-generation shoulder prosthesis

Reconstruction of the anatomy of the proximal humerus is a prerequisite to achieving good long-term clinical results after shoulder arthroplasty. Modern, adjustable prostheses have greater flexibility of inclination, retroversion, and medial and dorsal offset in comparison with older prostheses. Such improvements should allow for better reconstruction of the centre of rotation compared to older prostheses. Reconstruction of the humeral head centre was assessed in 106 modern adjustable (Affinis) and 47 second-generation prostheses. All reconstructions were compared both to the preoperative state and the unoperated shoulder. To describe the pre- and postoperative states, the geometry and position of the humeral head in relation to the glenoid were analysed on patient radiographs. Applying the defined parameters, modern adjustable prostheses showed better reconstruction than second generation prostheses. Parameter values measured in reconstructions using fourth generation prostheses were comparable to those of the unoperated shoulder, but differed significantly from the preoperative state. Second generation prostheses, in contrast, only show non-specific differences in parameter values. This suggests that an approximate reconstruction of normal anatomy can be achieved using a modern fourth generation prosthesis. Reconstruction of the complex anatomy of the proximal humerus is significantly better with modern adjustable prostheses compared to second generation prostheses. Improved clinical outcome can therefore be predicted in a functional and intact rotator cuff. The advantage of using modern prostheses systems over older models is clearly demonstrated in this study

Prospective study of double-eccentric hemi shoulder arthroplasty in different aetiologies: midterm results

This prospective study aimed to analyse the effect of a newly developed double-eccentric adjustable stemmed prosthesis on reconstruction of the osseous anatomy, range of motion, strength and pain relief. A total of 91 consecutive hemiprostheses were evaluated preoperatively and three, six, 12, 24 and 48 months postoperatively (mean±SD 46.2 ± 10.9 months) by the American Shoulder and Elbow Surgeons (ASES) and Constant scores as well as radiological assessment. Clinical evaluations showed an increase in Constant score from 21.9 to 64.8 points and in ASES score from 24.9 to 77.9 points after two years. The results depend mainly on the underlying pathology. The best results were observed for primary osteoarthritis and avascular necrosis of the humeral head. All heads were eccentrically positioned. Specific stem-related complications were not observed. Because of the eccentric positioning of all heads it is reasonable to use adjustable shaft prostheses. The clinical results are comparable to data in the literature. Additional study provided a better or comparable clinical outcome and a low revision rate, when compared with other modern adjustable implants in the literature