The use of biologic acellular matrices for the surgical augmentation of rotator cuff lesions has greatly expanded inrecent years. The study team patented a method for removing cells from human dermis (Acellular Dermal Matrix), maintaining unaltered biological and structural integrity. Acellular Dermal Matrix has been succesfully used for rotator cuff surgical repair augmentation beside in a limited number of patients. The aim of the project is to demonstrate the therapeutical efficacy of this strategy in patients affected by rotator cuff massive tears. Acellular Dermal Matrix will be also combined with autologous orthobiologics.

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