Objectives: Our aim was to characterize the ultrasonographic features of patients with acute Charcot neuroarthropathy (CN) of the foot.
Methods: In this prospective study, 26 patients with CN of the foot proved by MRI were enrolled. All patients were in early stage of CN with normal radiography (grade 0 modified Eichenholtz classification system). Ultrasonographic examination of mid-tarsal and ankle joints was performed with a 7-15 MHz linear probe.
Results: Ages of our patients ranged from 38 to 67 years (57.3 ± 6.4). About 96.2% of our patients (25 patients) had diabetes mellitus. Ultrasonographic findings were as follows: effusion/synovitis (100%) with high Doppler activity (92.3%) in the mid-tarsal joints, and effusion/synovitis (92.3%) and high Doppler activity (84.6%) in the ankle joints. Bone erosions were present in the distal fibula in 23 patients (79.3%), while in distal tibia in 9 patients (34.6%). Tendonitis was found in tibialis posterior tendons in 23 patients (88.4%), and in peroneal tendons in 22 patients (84.6%). A combination of active synovitis (in mid-tarsal joints and ankle joints), active tendonitis (of tibialis posterior and peroneal tendons), and erosions in the distal end of fibula was present in 21 patients (80.8%).
Conclusions: Ultrasonography is able to detect soft tissue inflammation and pre-radiographic bony changes in early stages of CN. Key Points •Ultrasound is a useful diagnostic tool for pre-radiographic stages of Charcot joint. •High-grade synovitis, high-grade tenosynovitis, and bony erosions are highly suggestive of Charcot arthropathy.
Keywords: Charcot; Erosions; Neuropathic arthropathy; Ultrasound.