Imaging findings in arthrofibrosis of the ankle and foot

Arthrofibrosis is defined as joint pain and stiffness that does not allow functional range of motion and is due to adhesions or contracture of the joint. Arthrofibrosis is characterized by an abnormal proliferation of fibrous tissue that may be focal or diffuse and intra-articular or extra-articular. Trauma and surgery are the most common etiological factors. In the ankle and foot symptomatic arthrofibrosis is not uncommonly seen in the talocrural joint, posterior subtalar joint, and the metatarsophalangeal joints. Imaging can assist with diagnosis and planning treatment, most commonly using MRI and occasionally ultrasound. Typical imaging findings consist of capsular and pericapsular thickening and scarring, best demonstrated on proton-density MR images but also demonstrable on ultrasound.