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Generally, it implies removal of a small piece of the surface of the acromion that is in contact with a tendon of the rotator cuff causing, by friction, damage to the tendon.
Frank, Jonathan M.; Chahal, Jaskarndip; Frank, Rachel M.; Cole, Brian J.; Verma, Nikhil N.; Romeo, Anthony A. (April 2014). "The Role of Acromioplasty for Rotator Cuff Problems". Orthopedic Clinics of North America. 45 (2): 219–224. doi:10.1016/j.ocl.2013.12.003. PMID24684915.
Barfield, L Cole; Kuhn, John E (February 2007). "Arthroscopic versus Open Acromioplasty: A Systematic Review". Clinical Orthopaedics and Related Research. 455: 64–71. doi:10.1097/BLO.0b013e31802f5436. PMID17159578.
Lavignac, Pierre; Lacroix, Paul-Maxime; Billaud, Anselme (June 2021). "Quantification of acromioplasty. Systematic review of the literature". Orthopaedics & Traumatology: Surgery & Research. 107 (4): 102900. doi:10.1016/j.otsr.2021.102900. PMID33771721.