Rotator cuff tear is a very common and disabling condition that can be related to acute trauma such as falling on the shoulder. A tear is associated with symptoms such as pain in abduction, abduction weakness and night pain. Rotator cuff tear surgery is a well-established form of treatment in acute rotator cuff tears, although beneficial results have been reported for both conservative and surgical treatment of rotator cuff tears. Rotator cuff tear repair surgery involves a considerable amount of re-ruptures, and it is possible that the repaired tendon do not heal despite surgical repair. On the other hand rotator cuff tears are also found in completely asymptomatic persons and the clinical significance of a rupture may be generally lower than estimated. The above-mentioned factors, as well as recent research and meta-analysis on the treatment of mainly degenerative rotator cuff tears indicate that there is a limited evidence that surgery is not more effective in treating symptomatic rotator cuff tear than conservative treatment alone. However, these previous research findings cannot be applied directly to traumatic tears, although degeneration can be considered always to contribute to the creation of a rotator cuff tear.

During few last decades, despite the lack of evidence on the superiority of one treatment over another, the use of surgery to treat this disorder has been substantially increased. Treatment expectations are found to be important in predicting patient related outcome measures. In addition, surgery itself may produce a profound placebo effect. There are no previous placebo-controlled trials on the topic of interest. In order to find out the true efficacy of surgical treatment of acute, trauma related rotator cuff tears involving mainly the supraspinatus tendon, the investigators have designed this multi-centre, randomized, placebo-controlled efficacy trial.

Inclusion Criteria:

1. Age of patient over 45 and below 70 years
2. Acute onset of shoulder symptoms after a traumatic event (any kind of sudden stretch, pull, fall, or impact, on the shoulder that is associated with the onset of symptoms)
3. Shoulder symptoms relating to rotator cuff tear = pain laterally on the shoulder and/or painful motion arc during abduction or flexion
4. MRI documented full thickness supraspinatus (ssp) tear

Exclusion Criteria:

1. Traumatic event of the shoulder due a criminal act of violence with legal consequences
2. A delay of more than 4 months after the onset of symptoms of trauma to the day of intervention
3. Arthroscopically documented partial thickness rotator cuff tear only
4. A large MRI documented full thickness rotator cuff tear, sagittal tear size at the level of footprint larger than 3cm
5. MRI or arthroscopically documented total width of infraspinatus (isp) or subscapularis (ssc) tear
6. MRI or arthroscopically documented fully dislocated biceps tendon (biceps out of the groove) with concomitant subscapularis tear
7. Positive clinical rotatory lag sign (ER1 lag (>10 degrees), lift off lag (involuntary drop against the back), horn blower lag (involuntary internal rotation of the forearm in supported elevated position))
8. Marked fatty degeneration in any of the cuff muscles (more than Fuchs/Goutallier grade 2)
9. Radiographically or MRI documented concomitant fracture line of the involved extremity or bony avulsion of the torn tendon or dislocation of the humeral head or the acromioclavicular joint.
10. Concomitant clinically detectable motoric nerve injury affecting the shoulder
11. Radiographically documented severe osteoarthritis of the glenohumeral joint, Samilson-Prieto 2 or above
12. Non-congruency of the glenohumeral joint in radiographs (Hamada stage 2 or above)
13. Clinical stiffness of the glenohumeral joint (severely limited passive range of motion: glenohumeral external rotation < 30 degrees, and abduction with stabilized scapula <60 degrees)
14. Previous surgery of the affected shoulder (affecting clavicle, scapula or upper third of the humerus)
15. Earlier sonographic or MRI finding of a rotator cuff tear
16. Previous symptoms of the ipsilateral shoulder requiring conservative treatment (glucocorticosteroid injections and/or physiotherapy) delivered by health care professionals during the last five years
17. Systemic glucocorticosteroid or antimetabolite medication during the last 5 years
18. Ongoing treatment for malignancy
19. ASA classification 3 or 4
20. Patient's inability to understand written and spoken Finnish, Norwegian or Swedish
21. History of alcoholism, drug abuse, psychological or other emotional problems likely to jeopardise informed consent
22. Patients with a contraindication/noncomplience for MRI examination or use of electrocautery devices
23. Previous randomization of the contralateral shoulder into the ACCURATE trial
24. Patient's denial for operative treatment and/or participation in the trial