 Primary outcome is overall shoulder function evaluated with the Constant score. As additional measures of shoulder function, the Dutch Oxford Shoulder Test and the Disabilities of the Arm Shoulder and Hand questionnaire will be assessed. Other evaluations include cosmetic appearance evaluated by the Popeye deformity, arm cramping pain, elbow flexion strength, MRI evaluation, quality of life, and cost of surgery. To detect non-inferiority with a one-sided, two-sample t-test with a 80 power and a significance level alpha of 0.025, the required sample size is 98 patients. 