Initial site of calcifications in rotator cuff tendons: A sonographic observational study.

BackgroundThis study aimed to investigate the initial site of calcification development in rotator cuff tendons using serial ultrasonographic evaluations.MethodsA total of 21 patients with de novo calcifications were included. Ultrasonography was used to assess calcifications in the rotator cuff tendons. The distance from the tendon insertion on the humerus to the calcification site was measured, along with the long and short diameters and the long-to-short diameter ratio.ResultsIn 19 patients (90%), calcifications were in direct contact with the tendon insertion on the humerus. In the remaining two patients (10%), the calcifications were located 1 mm proximal to the tendon insertion site. The mean long and short diameters of the calcifications were 9.4 ± 4.6 and 2.7 ± 1.2 mm (range: 3.0-17.0 and 1.0-4.5 mm), respectively. The mean long-to-short diameter ratio was 2.4 ± 2.2 mm (range: 1.8-10.0 mm). Regarding shoulder disorders, 1, 7, and 13 patients had a rotator cuff tendon tear, calcific tendinitis, and adhesive capsulitis, respectively.ConclusionsCalcifications in the rotator cuff tendons appear to originate at the tenoperiosteal junction or in close periosteal proximity and extend along the tendon axis.