Intraarticular lesions in calcifying tendinitis: incidence and association with the acromion index

Intraarticular pathologies are a common finding during arthroscopy for rotator cuff lesions. Both rotator cuff tears as well as cartilage lesions have been described as correlating with the acromion index.

In the current study, we aimed to determine the incidence of intraarticular lesions in calcifying tendinitis, to compare the incidence in patients with partial- and full-thickness tears of the rotator cuff, and to determine the acromion index in these groups. The incidence and type of accompanying intraarticular lesions were compared between three consecutive, age-matched groups of 64 patients each: those with calcifying tendinitis (group A), and those with partial- (group B) and full-thickness rotator cuff tears (group C). Also, the acromion index was measured from plain radiographs and compared between the groups.

The incidence of intraarticular pathology was 43% in group A, 41% in group B and 84% in group C. The differences between groups A and C as well as B and C were significant (p < 0.0001), but not between groups A and B (p = 0.858). Even though the acromion index was larger in group C than in the other two groups, the difference was not significant (A vs. B, p = 0.505; A vs. C, p = 0.180; and B vs. C p = 0.446). The incidence and type of intraarticular lesions in calcifying tendinitis are comparable to age-matched shoulders with partial- rather than full-thickness rotator cuff tears.

The acromion index is not different between shoulders with calcifying tendinitis, and partial- or full-thickness rotator cuff tears.