Problem: The displacement of the rotation centre of the humeral head in relation to the shaft axis strongly varies individually. In order to measure the position of the pivot points of the head, the Affinis shoulder prosthesis has a double eccentric adjustment possibility that permits to adapt the head to the medial and dorsal offset. So far, such examinations took place exclusively on the anatomical preparation. This raises the question of whether the need for such a prosthetic system can be derived from the anatomical variation of the pivot points.

Method: In 126 patients with an Affinis shoulder prosthesis, we calculated the individual rotation centres of the head from the position of the adjustable prosthetic cone and the eccentric position of the head. In addition, we used the Constant Score to record the clinical function.

Results: We found great variation of the rotational centres. Therefore we needed the entire setting range of 12mm mediolateral and 6mm dorsoventral. The examination showed that none of the found anatomic head centres could have been reconstructed exactly with a conventional prosthesis. Prosthesis with a single eccentricity would allow correct adjustment in only 22 cases, as the adjustable rotational centres of the head are situated on a circle, which limits the setting possibilities. The Constant Score of the total group improved from 29% preoperatively to 94% after 2 years.

Conclusions: The high variation of the head centres indicates the necessity of a freely adjustable system, such as in a double eccentric bearing. This is the only way that permits an optimal reconstruction of the anatomical conditions – it prevents an increased tension of the rotator cuff, reduces the eccentric loading of the glenoid and creates the prerequisites for the anatomical kinematics. The good clinical results speak for the need to observe bony balancing.

Introduction: In the evaluation of the major joints, self assessment tools have become wide spread aiming at a more precise quantification of joint function. Different tools have been developed for the elbow joint. However, there are only few data on the relationship between subjective self-assessment of joint function and objective measures.

We developed a comprehensive assessment set for the evaluation of subjective elbow function and objective clinical findings and investigate long-term results after implantation of GSB III Elbow arthroplasties in a first study. The PREE-G was cross-culturally adapted, following the recommendations of the American Association of Orthopedic Surgeons.

Material and Methods: 79 patients (56 female, 23 male, mean age 64 years) after elbow arthroplasty between 1984 and 1996 due to rheumatoid (59) or posttraumatic (20) arthritis underwent an assessment of the joint function using the PREE, the Short Form 36 (SF-36), the Disabilities of Arm, Shoulder, Hand (DASH)) and the modified American Shoulder and Elbow Surgeons (mASES) for a clinical evaluation. In 62 patients implantation was performed unilaterally and in 17 patients bilaterally, resulting in 96 elbow joints altogether. The mean follow up time was 11,2 years

Results: In the SF-36 score, the mean physical component scale (PCS) was worse (37,2 vs 41,7, p=0,004), the mean mental component scale (MCS) better (52,3 vs 50,3, p=0,092) than normative values of a German population. Subjective assessment by the PREE revealed a mean of 66,8, by the mASES of 63,1 and by the DASH of 56,5 points. Clinical examination resulted in a mean mASES score of 71,6 points. Comparison between the patients self assessment and the objective score revealed a significant correlation between the DASH (r=0,46, p< 0,001), PREE (p=0,54, p< 0,001) and mASES (r=0,60, p< 0,001) with the clinical mASES. In contrast, no significant correlation was found between the physical component scale (PCS) and mental component scale (MCS) of SF-36 and the clinical mASES. Also the patients assessment scores DASH, PREE and mASES showed a strong significant correlation among one another (r=0,74–0,92, p< 0,001) and (PCS) (r=0,58–0,75, p< 0,001) but not with the (MCS) of SF-36.

Conclusion: Assessment of long term results after elbow arthroplasty yielded favourable clinical and subjective results. The clinical outcome tended to be higher than results of the patient self-rated scores. Hereby, the newly developed assessment set proved to be a feasible tool for a comprehensive assessment of elbow function. In addition to clinical outcome assessment, with this set it is possible to gain important and new insights on the relationship between objective measures and subjective patients-assessment of elbow disorders and postoperative conditions.