Ultrasonographic features of acute Charcot neuroarthropathy of the foot: a pilot study

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.