Arthroscopic Treatment of an Unusual Intramuscular Calcium Hydroxyapatite Crystal Deposit on the Rotator Cuff.

Hydroxyapatite crystal deposition disease and its pathophysiology are poorly understood; however, it is known that calcific tendinitis is the most common condition related to this deposition in the upper limb. Movement of the crystals toward the myotendinous junction is rare; to the best of our knowledge, only 19 cases have been described in the literature, one of which was a case of intramuscular deposition without migration. The purpose of this technical note is to describe the technical details of the arthroscopic treatment of intramuscular calcium hydroxyapatite deposits without intratendinous migration.