Exercise treatment of patients with long-standing subacromial pain

Subacromial pain is the most common problem among patients with shoulder complaints seeking primary care. The recommended treatment for these patients is primarily non-surgical with a focus on exercise treatment. If this treatment fails arthroscopic subacromial decompression (ASD) followed by exercise treatment is recommended. Surgical treatment with ASD has increased substantially in Sweden in recent years even though studies comparing exercise treatment with surgery report equally positive results. Still, there is a need of evidence based preand postoperative exercise treatments, standardised and described in detail, to guide treatment of these patients in clinical practice. The overall aim of this thesis was to evaluate the efficacy of pre- and postoperative exercise strategies on shoulder function and how the preoperative strategy affects the need for surgery in patients with long-standing subacromial pain. This thesis comprises four papers which are based on two randomised controlled trials. In study A, patients were randomised after ASD surgery to either physical therapist (PT) supervised strength-endurance exercises for the rotator cuff and scapula stabilisers or to home-based movement exercises for a period of three months. Shoulder function and pain, health related quality of life and return to work was evaluated for 6 months (paper I). In study B, patients on the waiting list for surgery were randomised to either specific exercise strategy with strengthendurance exercises for the rotator cuff and the scapula stabilisers or to control exercises with movement exercises for the neck and shoulders for a period of three months. After completing the exercise program and also after 12 months, shoulder function and pain, need for surgery and health related quality of life was evaluated. Baseline shoulder function, rotator cuff status and radiological findings were analysed in relation to the choice of surgery (paper II, III). The minimal important clinical change (MIC) of the Constant-Murley (CM) score, used as primary outcome in this thesis, was determined by using a visual anchor-based MIC distribution method (paper IV). Six months after ASD surgery, patients who performed PT-supervised strength-endurance exercises improved significantly more in shoulder function and pain compared to patients who had performed home-based movement exercises (paper I). Patients on the waiting list for surgery who performed specific strength-endurance exercises had significantly greater improvements in shoulder function and pain compared to patients performing movement exercises (paper II). A significantly lower proportion of those performing specific strength-endurance exercises chose surgery at the three- and 12 months follow-ups (paper II, paper III). Low baseline values in shoulder function and pain measured with the CM score and/or having a full thickness rotator cuff rupture were associated with an increased risk of choosing surgery (paper III). Regarding the CM score, a change between 17-24 points seems to be clinically important for patients with long-standing subacromial pain (paper IV). Supervised strength-endurance exercises seem to be more effective than home-based movement exercises after ASD surgery. For patients on the waiting list for surgery, the specific strategy of strength-endurance exercises was effective in improving shoulder function and pain and the need for surgery was reduced at 12 months. Low baseline values for shoulder function and pain measured with the CM score and/or having a full thickness rotator cuff tear seem to be predictors for choosing surgery. The CM score is able to detect the MIC in individual patients with long-standing subacromial pain when the rotator cuff is intact. In all patients with longstanding subacromial pain, the MIC value was dependent on the subgroup as well as the choice of statistical analysis