The aim of the present study is to determine the frequency of enthesopathy in fibromyalgia (FM) by using a newly developed ultrasonography (US) method, the Madrid Sonography Enthesitis Index (MASEI).
This study was conducted on 38 consecutive patients with FM and 48 healthy sex- and age-matched controls. Six entheseal sites (olecranon tuberosity, superior and inferior poles of patella, tibial tuberosity, superior and inferior poles of calcaneus) on both lower limbs were evaluated. All US findings were identified according to MASEI. Scores of patients and controls were compared by Student's t-test and Mann-Whitney U-test. Validity was analysed by receiver operating characteristic curve. Values of P < 0.05 were considered significant.
Total enthesitis score was 7.39 ± 4.99 (mean ± SD) among FM patients and 3.7 ± 3.22 among healthy controls (P < 0.001). The receiver operating characteristic curve established an ultrasound score of > 3.5 in the FM group as the best cut-off point to differentiate between cases and controls. No statistically significant correlation was found between the MASEI score and the FM disease duration, and the location of the tender points.
Misdiagnoses of FM are harmful to patients and the community, and the presence of enthesopathy among FM patients increases. Its detection with the MASEI score may help to discriminate FM patients presenting with ill-defined symptoms and signs, in order to prevent mistreatment.