Association of steroid injection with soft-tissue calcification in lateral epicondylitis

Abstract

Background: Steroid injections are among the most commonly used conservative treatments for lateral epicondylitis (LE). Although soft-tissue calcification has been reported as a steroid injection complication in certain tendons, such an association in LE has not been established. This study's purpose was to determine any association of both a history of steroid injection and the number of steroid injections with the types of calcification found in LE.

Methods: This study included 110 patients (110 elbows) with LE diagnosed from February 2016 to October 2017. We categorized calcifications seen on standard elbow radiographs as soft-tissue calcifications or enthesophytes using the classification of Shillito et al. Using logistic regression analyses, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) for various factors possibly affecting calcification in LE: age, sex, body mass index, dominant-side involvement, occupation, symptom duration, hand-grip power, pain score on a visual analog scale, and treatment methods. The evaluated treatments included stretching exercise, extracorporeal shockwave therapy, and steroid injections.

Results: In the univariate analysis, the visual analog scale pain score, a history of steroid injection, and the number of steroid injections were significantly associated with soft-tissue calcification (P ≤ .020). In the multivariable analysis, a history of steroid injection (OR, 7.63; 95% CI, 1.63-35.72) and the number of steroid injections (OR, 1.18; 95% CI, 1.06-1.32) were significantly associated with soft-tissue calcification (P ≤ .010).

Conclusions: The significant association of steroid injections with soft-tissue calcification in LE suggests that this calcification is likely to be an iatrogenic complication of steroid injection.

Keywords: Complication; Conservative treatment; Enthesophyte; Lateral epicondylitis; soft-tissue calcification; steroid injection.