Inclusion Criteria:

• patients affected by large to massive lesion according to Gerber involving supraspinatus and infraspinatus tendons
• tendon retraction <=3 according to Thomazeau
• fatty degeneration <=3 according to Goutallier
• possibility to obtain tendon reduction,
• pre-operative Magnetic Resonance Imaging,
• ability to read, understand and complete outcome scores

Exclusion Criteria:

• patients affected by osteoarthritic degeneration,
• frozen shoulder,
• symptomatic acromioclavicular arthritis,
• revision surgeries,
• inability to cope with post-operative rehabilitation regimen,
• autoimmune connective tissue disease,
• current or past hematologicaldisorders,
• comorbidities affecting healing,
• active infections,
• cancers,
• pregnancy and lactation