Freiberg infraction affects the metatarsal head (usually the second or third metatarsal head) and is characterized at pathologic analysis by collapse of the subchondral bone, osteonecrosis, and cartilaginous fissures. The cause of Freiberg infraction is controversial and is probably multifactorial. A traumatic insult in the form of either acute or repetitive injury and vascular compromise are the most popular theories. Freiberg infraction is more common in women and most commonly manifests during adolescence. High-heeled shoes have been implicated as a causative factor. Patients may present with pain and limited motion, although symptoms may not begin until osteoarthrosis has developed.

Radiograph demonstrating Freiberg infraction

• Early MR imaging findings include low-signal-intensity changes in the metatarsal head on T1-weighted images with increased signal intensity on corresponding T2-weighted and STIR images.
• With disease progression, flattening of the metatarsal head occurs, and low-signal-intensity changes develop on T2-weighted images as the bone becomes sclerotic.