Introduction Shoulder prosthesis of the third generation should allow a better restoration of the center of rotation in the replaced humeral head and a better adaptation to anatomical complex situations. Finally this should lead to an improved functional outcome compared with common types of prosthesis. We performed a retrospective study using the far most accepted scores to assess functional outcome and quality of lifer in order to compare our results with the clinical literature.

Materials and Methods 107 patients with a total of 111 prosthesis out of 127 patients were evaluated 3 to 4 years after implantation of a cemented prosthesis of the third generation (Aequalis″< caron> ) combined with a pegged Glenoid. The functional outcome was evaluated with the following scores: DASH, ASES, SPADI and Constant score (CS). Quality of life was rated using short form 36 (SF-36). Further data were recorded using a comorbidity self-assessment, a sociodemographic and a transition questionnaire. Patient data from SF-36, DASH and Constant Score were compared with normative data from age-, sex- and comorbidity corrected control groups. Paired, non-parametric testing was performed with the Wilcoxon-Test and Bonferroni correction. Radiographs were taken in three standard planes and the glenoid was evaluated according to Lazarus et al.

Results The Constant score at the time of follow up reached with 72±16 97% of the norm population. The subscore pain improved in average from 3 to 12 (maximum 15) and the subscore mobility from 14 to 32 (maximum 40).

Patients with primary arthrosis (n=44) and patients with posttraumatic arthrosis (n=39) had no functional deficits compared to the normal population in contrast to patients with RA (n=17). They showed significantly functional deficits (p< 0.001) in the DASH score as well as in the physical sum scale of the SF-36 (p=0.008). The majority of glenoids showed an incomplete lyses around one dowel (grade I in 70%). Less than 2% showed grade III or IV.

Discussion Implantation of a shoulder prosthesis of the third generation leads to good functional results compared with the control population. Functional and physical deficits remain in patients with an underlying RA. Glenoid loosening seems to be of minor concern. Our results prove the good clinical results that are reported in the literature, however they have to be proven with a longer follow-up.