Bilateral stress fracture of the tibia diagnosed by ultrasound. A case report

Abstract

We report the case of a 35 years old patient presenting with bilateral pain in the medial aspect of both knees. Ultrasound examination revealed hyperechoic appearance of the subcutaneous tissue and periarticular soft tissue bilateral. Color Doppler studies showed significant vascular signals at the surface of the tibial plateaux. US appearance, together with clinical findings, suggested a diagnosis of simultaneous bilateral fatigue fracture. An MRI confirmed the diagnosis and the patient's symptoms resolved with rest. US may be a useful imaging tool in the diagnosis of stress fracture.

Keywords: Fatigue fracture; Sonography; Stress fracture; Ultrasound.

Figures

Figure 1

Coronal (top) and coronal colour Doppler (bottom) sonograms obtained over the medial aspect of the left knee. The grey-scale image shows thickening of the soft tissue located between the tibial cortex (white arrowhead) and the inferior part of the medial collateral ligament (black arrowheads). Colour Doppler shows flow signals due to local hypervascular changes.

Figure 2

Coronal PD fat sat MRI images obtained on both knees. MRI depicts the stress fracture (white arrows) as a low intensity, serpiginous, line surrounded by an ill-defined hyperintense area related to marrow oedema (black arrows). Note also hyperintensity (withe arrowheads) of soft tissues located between the medial collateral ligaments (black arrowheads) and the bone cortex related to local inflammation.

Figure 3

A-P standard radiographs of both knee show two roughly symmetric sclerotic lines (arrows) parallel to the articular surface. This aspect is typical of stress fracture.