Radiological and clinical predictors of long-term outcome in rotator cuff calcific tendinitis

Abstract

Objectives: Knowledge on the epidemiology and long-term course of rotator cuff calcific tendinitis (RCCT) is scarce. We assessed demographics, radiological characteristics, and their association with long-term outcomes in a large patient group.

Methods: Baseline demographics, radiological characteristics and treatment were recorded in 342 patients. Interobserver agreement of radiological measures was analyzed. Long-term outcome was evaluated with questionnaires (WORC, DASH). The association of baseline characteristics with outcome was assessed.

Results: Mean age was 49.0 (SD = 10.0), and 59.5 % were female. The dominant arm was affected in 66.0 %, and 21.3 % had bilateral disease. Calcifications were on average 18.7 mm (SD = 10.1, ICC = 0.84 (p < 0.001)) and located 10.1 mm (SD = 11.8) medially to the acromion (ICC = 0.77 (p < 0.001)). Gärtner type I calcifications were found in 32.1 % (Kappa = 0.47 (p < 0.001)). After 14 years (SD = 7.1) of follow-up, median WORC was 72.5 (range, 3.0-100.0; WORC < 60 in 42 %) and median DASH 17.0 (range, 0.0-82.0). Female gender, dominant arm involvement, bilateral disease, longer duration of symptoms, and multiple calcifications were associated with inferior WORC. DASH results were similar.

Conclusions: Many subjects have persisting shoulder complaints years after diagnosis, regardless of treatment. Female gender, dominant arm involvement, bilateral disease, longer duration of symptoms, and multiple calcifications were associated with inferior outcome. Radiological measures had moderate-to-good reliability and no prognostic value.

Key points: • Most RCCT studies report on short-term outcome and/or small patients groups. • In this large, long-term observational study, RCCT appeared to not be self-limiting in many subjects. • Negative prognostic factors included female gender, more calcifications, dominant arm affected, and longer duration of symptoms. • Interobserver agreement of general radiological RCCT measures is moderate to good. • More rigorous diagnostics and treatment might be needed in specific RCCT cases.

Keywords: Calcific tendinitis; Epidemiology; Long-term; Rotator cuff; Treatment.

Fig. 1

Study flowchart

Fig. 2

Locations of the calcific deposits were evaluated using the system of Ogon et al., which we refer to as Location in this paper [3]. A line perpendicular to the most lateral border of the acromion is drawn, parallel to the glenoid, on external rotation AP radiographs. Location is the distance (mm) between this line and the medial border of the calcification, where negative values represent a medial calcification border, i.e. between the glenoid and the drawn line

Fig. 3

Examples of Gärtner calcification classification types [6]. A) Gärtner type I: sharp border and a dense structure; B) Gärtner type II: either a sharp border and an inhomogeneous structure or a vague border and a homogenous structure; C) Gärtner type III: a vague border, more or less transparent in structure and a cloudy appearance

Fig. 4

Histograms of the clinical scores A) WORC score: 55 % had inferior long-term functional outcome, with scores below 80 percentage points; B) DASH score: 45 % scored had scores over 20 points, indicating disability