Shoulder arthroscopy is a minimally invasive procedure frequently used for rotator cuff repair. Patients may experience severe postoperative (PO) pain, that can last for a month and can influence successful rehabilitation. Our study aimes to evaluate the effectiveness of interscalene brachial plexus single-shot (ISBSS) versus continuous interscalene brachial plexus block (ISBC) in controlling perioperative pain and avoiding PO pain chronicization. This prospective randomized unblinded trial hypothesizes that the PO perineuronal infusion using a continuous ambulatory delivery device pump gives better pain control and outcomes than ISBSS during the long-term follow-up period.