The primary objective of this study is to examine quality of life outcomes in patients who have undergone a humeral surface replacement hemiarthroplasty.

Resurfacing arthroplasty is gaining popularity for the reconstruction of advanced shoulder arthritis. New generation re-surfacing prostheses are engineered to anatomically restore a smooth articulating surface to the humeral head, while preserving bone stock, and potentially minimizing the risk for diaphyseal fracture. The results for shoulder resurfacing prostheses have largely been reported in retrospective reviews and have been very favorable. The purpose of this multi-centered, prospective study will be to determine the extent to which patient self-assessed outcomes (American Shoulder and Elbow Society (ASES) Score) following humeral resurfacing improve compared to pre-operative ASES scores.

Pre-Operative Inclusion Criteria:

• Failed standard non-surgical management (analgesics, nsaids, physiotherapy, activity modification)
• Persistent pain and disability for at least 6 months
• Imaging demonstrates advanced humeral head cartilage loss

Pre-Operative Exclusion Criteria:

• Active or systemic joint infection
• Significant muscle paralysis of shoulder girdle
• Charcot's Arthropathy
• Major medical illness (life expectancy <2years)
• Unable to speak and read English/French
• Psychiatric illness that precludes informed consent
• Unwilling/unable to remain in study for one year

Intra-Operative Inclusion Criteria:

Advanced humeral head cartilage loss AND ONE of:

• minimal/no glenoid cartilage loss
• complete glenoid cartilage loss and no bony erosion
• complete glenoid cartilage loss and concentric bony erosion with no humeral anterior/posterior subluxation

Intra-Operative Exclusion Criteria:

• Eccentric glenoid erosion with biconcavity of glenoid and subluxation of humeral head
• Inability of humeral head to support the CAP surface replacement