Foot and Toes

Abstract

Ultrasound of the foot, including structures from the subtalar joint distally, is helpful for evaluation of pain, and guided injections can improve the accuracy of needle placement. The subtalar (talo-calcaneal) joint can be a source of inflammatory arthritis and is visualized anterolaterally or posterolaterally. The sinus tarsi, seen anterolateral to the ankle joint, between the talar neck and anterior process of the calcaneus, is easily seen for guided injections. Obvious incongruity of the tarso-metatarsal (Lisfranc) joints may be apparent in midfoot trauma but will need radiographs and perhaps advanced imaging. Thickening of the plantar fascia is easily seen in plantar fasciitis, and ultrasound facilitates accurate needle therapies. The first metatarsophalangeal joint can be difficult to obtain fluid from unless ultrasound aids in needle aspiration. Interdigital neuromas are sometimes visible, and injection of these with guidance is safer to nearby vascular structures.