Prosthesis Versus Active Exercise Program in Patients With Glenohumeral Osteoarthritis

Anatomical total shoulder arthroplasty (TSA) is a well-established treatment for pronounced glenohumeral osteoarthritis. However, the effectiveness of TSA has not been compared to non-surgical treatment in a randomised controlled trial. Shoulder exercises may be an effective treatment for reducing pain and improving function in glenohumeral osteoarthritis. The primary aim of this trial is to examine if TSA followed by standard postsurgical rehabilitation is superior to a 12-week exercise programme in patients with primary glenohumeral OA eligible for unilateral TSA. We hypothesise that surgical intervention followed by standard rehabilitation, results in clinically relevant (18-point, on a scale from 0-100) improvement compared to the exercise intervention.

Glenohumeral osteoarthritis causes pain, stiffness and weakness in the shoulder joint, and furthermore, it affects activities of daily living and quality of life. Anatomical total shoulder arthroplasty (TSA) is a well-established treatment for pronounced glenohumeral osteoarthritis. Several studies have suggested the need for trials comparing shoulder arthroplasty to non-surgical treatments. The ProAct trial is a Nordic multicenter randomized controlled trial. Patients with glenohumeral osteoarthritis, eligible for a TSA will be randomised to either TSA followed by usual care or exercise only. The exercise intervention consists of 12 weeks of exercise with one weekly physiotherapist-supervised exercise session. The primary outcome will be the total the Western Ontario Osteoarthritis of the Shoulder index score at 12 months follow-up.Outcome assessment will be performed at baseline, and at 3 and 12 months and 2-, 5- and 10 years after start of surgical/non-surgical treatment. Patients fulfilling the eligibility criteria but declining to participate in the randomised trial will be offered the option of participating in an observational cohort using the same primary end point and patient reported outcomes, but following usual clinical practice.

Inclusion Criteria: * Patients ≥55-85 years * Moderate-severe primary OA of the glenohumeral joint according to Samilson and Prieto, by measuring the lower osteophyte (32) * Eligible for surgery with standard TSA Exclusion Criteria: * Surgical need for bonegraft * Previous shoulder fracture (fracture of the proximal humerus or glenoid fracture) * Planned other upper extremity surgery within six months * Rheumatoid arthritis or other types of arthritis not diagnosed as primary glenohumeral OA * Cancer diagnosis and receiving chemo-, immuno- or radiotherapy * Neurological diseases affecting shoulder mobility (e.g. disability after previous stroke, multiple sclerosis, Parkinson's, Alzheimer's disease) * Other reasons for exclusion (i.e. mentally unable to participate) or planned absence for more than 14 days in the first 3 months after baseline test. * Unable to communicate in the participating countries respective languages