Rotator cuff calcifications in pseudoxanthoma elasticum: a comparative analysis of prevalence and anatomical...

To investigate the prevalence, number, size, and distribution of rotator cuff calcifications in pseudoxanthoma elasticum (PXE) patients, relative to a comparison cohort, using computed tomography (CT).

This single-center retrospective study included adult PXE patients with available low-dose full-body CT scans, compared with a cohort of adult patients undergoing full-body 18F-fluordeoxyglucose-positron emission tomography/CT (FDG-PET/CT) scans. A blinded musculoskeletal radiologist assessed the presence, number, size, and location of rotator cuff calcifications on thin-slice axial CT images (1-2 mm), with multiplanar reconstruction. The association between disease status and calcifications were analysed using age- and sex-adjusted multivariable logistic and negative binomial regression, and mixed-effects models for anatomical locations.

Two hundred sixty-nine PXE patients (51 ± 14 years, 64% female) and 124 non-PXE patients (55 ± 16 years, 50% female) were included. A total of 138 calcifications in 82 PXE patients (prevalence, 30%; median largest calcification length, 6.0 mm; IQR 3.0-8.0) and 48 calcifications in 30 non-PXE patients (prevalence, 24%; median largest calcification length, 4.5 mm; IQR 3.0-7.0) were detected. No significant association between PXE and the presence (adjusted OR 1.54, 95% CI 0.92-2.63) or number of calcifications (adjusted RR 1.37, 95% CI 0.89-2.09) was found. However, PXE patients had an increased odds of intratendinous calcifications (adjusted OR 2.56, 95% CI 1.09-6.03) and a higher number of calcifications at this site (adjusted RR 2.31, 95% CI 1.18-4.52).

PXE was not significantly associated with the overall presence or burden of rotator cuff calcifications, but showed an increased odds of intratendinous involvement.