Tendon involvement in patients with gout: an ultrasound study of prevalence

Abstract

The objective of the present study is to evaluate, by ultrasonography (US), the prevalence in the quadriceps, patellar, and Achilles tendon involvement of gout compared to that of patients with osteoarthritis and asymptomatic marathon runners. This is a multicenter, multinational, transverse cross-sectional, and comparative study comprising 80 patients with the diagnosis of gout according to the American College of Rheumatology (ACR) criteria, compared with two control groups: 35 patients with generalized osteoarthritis according to the ACR criteria and 35 subjects who were healthy marathon runners. Demographics and clinical characteristics, such as age, gender, comorbidity, disease duration, pain at the enthesis in the knee and ankle, frequency of disease exacerbations, uric acid level more than 7.2 mg at the time of evaluation, and type of treatment, were recorded. All participants were examined by ultrasound at the quadriceps, the patellar at its proximal and distal insertion, and the Achilles tendon to detect intra-tendinous tophus or aggregates according to the OMERACT definitions. Descriptive statistics and differences between groups were analyzed by chi-square test. Sensitivity and specificity by US were calculated. The prevalence of intra-tendinous aggregates and tophi in gout was significant compared with the other groups. Both lesions were the most frequent at the distal patellar insertion, followed by the quadriceps, Achilles, and proximal patellar insertion ones. In patients with osteoarthritis (OA), intra-tendinous hyperechoic aggregates were observed in 20 % of quadriceps tendons and in 11 % of patellar tendons at its proximal insertion, while in the healthy marathon runner group, the Achilles tendon had this kind of lesion in 17 % of the subjects. Neither the OA nor the healthy marathon runners had intra-tendinous tophi. The sensitivity and specificity of US to detect tophi or aggregates were 69.6 and 92 %, respectively, tendon involvement at the lower limbs in gout is very frequent, particularly in the patellar tendon, and US possesses good sensitivity and specificity for detecting intra-tendinous tophi.

Brief Report: Monosodium Urate Monohydrate Crystal Deposits Are Common in Asymptomatic Sons of Patients With Gout: The Sons of Gout Study

“…We observed intratendinous hyperechoic deposits in 35.9% of participants with MSU crystal deposits elsewhere. This is consistent with previous reports of tendon involvement in gout (14,15). As shown in Table 2, a substantial proportion of tendon hyperechoic deposits occurred in subjects without ultrasonographic features of MSU crystal deposition in the first MTP joints.…”

Differences in Achilles tendon stiffness in people with gout.

“…Using shear wave elastography, we have for the first time, demonstrated that people with gout have significantly lower stiffness in the AT compared with age/sex matched non-gout participants. Tendon pathology in the lower limbs has been shown to be more frequent in those with gout than those with osteoarthritis or healthy controls [36]. The AT is reported to be a commonly involved site in tophaceous gout.…”

Differences in Achilles tendon stiffness in people with gout: a pilot study

“…Tendon pathology in the lower limbs has been shown to be more frequent in those with gout than in those with either osteoarthritis or healthy controls. [13,47] A systematic review and meta-analysis revealed that abnormal ultrasound ndings (i.e. tendon thickening, increased vascularity, hypoechogenicity) in the AT were predictive of tendinopathy.…”