Table 1 Inclusion and Exclusion criteria

Inclusion criteria

Diagnosis of RC tear: clinical grounds, MRI evidence of full-thickness RC tear,

Symptoms: history of shoulder symptoms refractory to non-operative management (non-steroidal anti-inflammatory drugs or injections, physiotherapy, rest)

Arthroscopic bilateral RC repair procedures; minimum follow-up of 1 month after surgery

Exclusion criteria

Associated pathologies of the shoulder: gleno-humeral instability with capsule-labral pathologies; fracture of the glenoid or the greater/lesser tuberosity of the humerus; inflammatory joint disease, glenohumeral osteoarthritis, RC arthropathy. Irreparable RC tears.

Bilateral RC disease

Follow-up < 12 months; inability to complete clinical questionnaires due to language problems or cognitive disorders