The purpose of the study is to investigate the fixation of the humeral component in total shoulder arthroplasty for primary osteoarthritis of the glenohumeral joint.Our hypothesis is that uncemented fixation of the humerus will result in better disease-specific quality of life, decreased incidence of radiographic loosening, decrease operative time and no increase in complications.

Currently, cement fixation of the humeral component is recommended as the standard of care and review of the literature indicates that this fixation is associated with a low complication rate. Uncemented fixation is promising in its potential to provide long-term, stable fixation yet comparative results to cemented stems are not available at this time.

Despite an absence of data to support their use, there has been an exponential increase in the use of uncemented humeral component fixation in shoulder arthroplasty. This push may be dictated by the desire to reduce operative time in an attempt to cut surgical expenses. This goal is particularly highlighted by the efforts of government and third party bodies to maximize return on limited funds. There is no conclusive clinical data at this time to suggest that uncemented fixation yields results that are better than cemented fixation in the shoulder.

This multi-centre, prospective, randomized double blinded clinical trial will compare cemented versus uncemented/tissue-ingrowth fixation of the humeral component in total shoulder arthroplasty. Patients are recruited from 10 centres across Canada by surgeons with extensive experience in total shoulder arthroplasty. Patients will be randomized to receive either a cemented or uncemented humeral stem. All other variables will be controlled for.

The main evaluation of patient outcome is disease-specific quality of life. Validated tools evaluating shoulder function are being used for this purpose, as required by various societies. These include the Western Ontario Osteoarthritis of the Shoulder Index (WOOS), the most responsive; Constant, preferred by European investigators; American Shoulder and Elbow Surgeons (ASES) Standardized Shoulder Assessment and Shoulder Score Index, preferred by the ASES. Overall global health status is measured using the SF-36. Several secondary outcomes are monitored for during the post-operative course. These are: shoulder function, radiographic evaluation of component fixation, operative time and the incidence of revision surgery and complications.

Inclusion Criteria:

1. Primary osteoarthritis of the shoulder of grade III or higher (Kellgren and Lawrence modified for the shoulder
2. Patients who have failed standard conservative management of their shoulder osteoarthritis

Exclusion Criteria:

1. Patients with secondary OA resulting from major joint trauma, infection, avascular necrosis, cuff tear arthropathy, chronic dislocation, massive rotator cuff tear, inflammatory arthropathy, Charcot's arthropathy or previous shoulder surgery (other than arthroscopic debridement)
2. Patients with preoperative CT scans of the shoulder which show insufficient glenoid bone stock that would not allow for implantation of a glenoid prosthesis
3. Active joint or systemic infection
4. Significant muscle paralysis
5. Major medical illness (life expectancy less then 2yrs or unacceptably high operative risk)
6. Unable to speak or read English/French
7. Psychiatric illness that precludes informed consent
8. Unwilling to be followed for 2 years