Ultrasound of ankles in the diagnosis of complications of chikungunya fever

Abstract

Objective: To describe the main ultrasound findings of chikungunya fever in the ankle.

Materials and methods: This was a cross-sectional observational study involving 52 patients referred to the Hospital Universitário Pedro Ernesto and presenting with clinical and biochemical evidence of chikungunya fever. The examinations were performed by a radiologist with more than 20 years of experience in ultrasound.

Results: The predominant gender was female (in 88.5%), and the mean age was 58.4 years. The majority (61.5%) of the patients came from the northern part of the city of Rio de Janeiro, and 46.2% were using corticosteroids to treat inflammatory symptoms. The most common alterations observed by ultrasound were joint effusion (in 69.2%), tenosynovitis (in 59.6%), cellulitis (in 46.2%), Kager's fat pad thickening (in 29.9%), myositis (of the soleus or flexor hallucis longus muscle) (in 17.3%), retrocalcaneal bursitis (in 5.8%), tendon ruptures (in 3.8%), and increased vascular flow on power Doppler (in 3.8%).

Conclusion: Signs of synovitis and tenosynovitis were the main ultrasound findings in a predominantly female population with a mean age of 58.4 years. Further studies are needed in order to define the role of ultrasound in the follow-up of such patients.

Keywords: Arboviruses; Chikungunya virus; Synovitis; Tenosynovitis; Ultrasonography.

Figure 1

Longitudinal sagittal image of the tibiotarsal joint space, performed with a linear transducer at 14 MHz, showing hypoechoic areas (arrows), characteristic of effusion.

Figure 2

A: Photo of the dorsal region of the left foot, which shows anterolateral bulging (arrows). B: Corresponding to the alteration observed in the physical examination, ultrasound of the long extensor tendon of the fingers, performed with a linear transducer at 14 MHz and acquired in the sagittal plane, shows distention of the tendon sheath by an anechoic fluid collection (arrows), which is characteristic of tenosynovitis.

Figure 3

Sagittal ultrasound image of the posterior calf region, performed with a linear transducer at 14 MHz, showing thickening and increased echogenicity of Kager's fat pad (arrows).

Figure 4

Sagittal panoramic view of the calf, performed by sweeping with a linear transducer at 14 MHz, showing diffuse hyperechogenicity of the soleus and flexor hallucis longus muscles, caused by myositis.

Figure 5

Sagittal image of the lower calf, performed with a linear transducer at 14 MHz, showing an anechoic fluid collection in the retrocalcaneal bursal projection (arrow), which is characteristic of bursitis.

Figure 6

Cross-sectional image of the fibularis brevis muscle tendon, performed with a linear transducer at 14 MHz, showing an extensive hypoechoic area, indicative of a partial rupture, in the posterior region.