Sonographic evaluation of the association between calcific tendinopathy and rotator cuff tear: a case-controlled comparison.

Abstract

To compare the incidence of rotator cuff (RC) tears on shoulder ultrasounds of patients with RC calcific tendinopathy (CaT) to that of a control group without CaT. In this retrospective case-control study, 50 shoulder ultrasounds of patients with CaT were compared independently by 2 musculoskeletal radiologists to 50 patients from a control group without CaT to catalog the number and type of RC tears. RC tears in the CaT group were further characterized based on location, into tears in the specific tendon(s) containing calcium versus all tendon tears. RC tears were diagnosed in 38% (19/50) of the control group (16 full-thickness) as compared to 22% (11/50) with CaT (6 full-thickness). The fewer full-thickness tears in the CaT group (12%, 6 of 50) compared to that in the control group (32%, 16 of 50) was statistically significant (P = 0.016, odds ratio 0.29). Only 7 of the 11 tears in the CaT group were in a calcium-containing tendon (3 full-thickness). The fewer calcium-containing tendon tears compared to tears in the control group was also statistically significant (P = 0.006, odds ratio 0.27). Furthermore, the fewer full-thickness calcium-containing tendon tears (6%, 3/50) compared to full-thickness tears in the control group (32%, 16/50) were yet more statistically significant (P = 0.001, odds ratio 0.14). In patients with shoulder pain and CaT, we observed a decreased number of RC tears and especially calcium-containing tendon tears, as compared to similar demographic patients with shoulder pain but without CaT. Key Points • Patients with rotator cuff calcific tendinopathy have few rotator cuff tears, especially full-thickness tears, compared to a control group without calcific tendinopathy. • The tendons containing the calcium hydroxyapatite deposition were the least likely to have a rotator cuff tear. • Future studies could evaluate if calcium hydroxyapatite deposition provides a protective mechanism against rotator cuff tears. • Musculoskeletal ultrasound is more sensitive than MRI in the evaluation of rotator cuff calcific tendinopathy.