Calcific Shoulder Tendinopathy (CT): Influence of the Biochemical Process of Hydrolysis of HA (Hydroxyapatite) on the Choice of Ultrasound-Guided Percutaneous Treatment (with the Three-Needle Technique)

Calcific shoulder tendinopathy (CT) is a common condition involving the central part or insertion of the rotator cuff tendons (RC) or the subacromial-subdeltoid bursa (SASD). The calcific deposits consist of poorly crystallized calcium hydroxyapatite but the mechanism of their formation still remains unclear. CT can be divided into three distinct stages, as reported by Uthhoff et al. Clinically, this condition varies with the extent of the calcification and the phase of the condition. In particular, the disorder is asymptomatic or may cause mild discomfort during the deposition of calcium, while it becomes acutely painful during the resorptive phase. US-PICT (ultrasound-guided percutaneous irrigation of calcific tendinopathy) is indicated in the acute phase (resorptive phase) of CT with significant pain relief and a very low rate of minor complications. The aim of this manuscript is to define the rationale of the ultrasound-guided percutaneous irrigation of calcific tendinopathy, correlating it with the sequence of biochemical processes that lead to the hydrolysis of hydroxyapatite. Furthermore, we will explain the reasons why we prefer using the three-needle technique for the dissolution of calcifications.