This study is designed as a multi-center, nonrandomized, uncontrolled, unblinded, prospective clinical outcomes investigation to evaluate the short, mid and long term performance of the PyroTITAN™ HRA Shoulder prosthesis humeral replacement. The PyroTITAN™ HRA Shoulder prosthesis device configuration will include humeral resurfacing CAP without cement. Patients will be selected for recruitment into the study based upon the normally accepted criteria for primary shoulder resurfacing arthroplasty.