Plantar fasciitis

Plantar fasciitis is one of the most common causes of heel pain, resulting from inflammation and microtearing of the plantar fascia — the thick band of connective tissue that runs along the bottom of the foot from the heel bone to the toes. On ultrasound, the hallmark finding is thickening of the plantar fascia, typically measuring greater than 4 millimeters at its insertion on the calcaneus (heel bone), compared to the normal thickness of about 2 to 4 millimeters. The affected fascia may also appear hypoechoic (darker) with loss of its normal fibrillar (striped) pattern, indicating edema and degeneration. Ultrasound is increasingly used as a first-line diagnostic tool for plantar fasciitis because it is readily available, inexpensive, and can be performed dynamically at the bedside. It can also guide therapeutic injections directly to the affected area.