Patient History

45-year-old woman with a history of leukemia (in remission), complaining of anterolateral ankle pain for 2 weeks with no inciting event.

Findings

SKELETAL/BONES:

Serpiginous area of alternating T1 hypointensity and T2 hyperintensity throughout the mid to posterior talar dome, consistent with avascular necrosis (double line sign). Greater than 75% of the articular surface is involved. Extensive reactive osteoedema throughout the talar dome, extending down the talar neck. No subchondral collapse. No T2 hyperintense subchondral fluid cleft to suggest instability. No displaced fragment.

Additional focal, round, 1.3 cm intraosseous abnormality within the dorsal calcaneus, consistent with a bone infarct. No surrounding reactive osteoedema.

Further separate small subarticular area of avascular necrosis at the talar head, at the talonavicular articulation. No articular/subchondral collapse. No unstable fragment.

No further focal osseous lesion. Bone marrow has normal signal. No permeative or marrow replacing osseous abnormality.

ARTICULATIONS:

Tibiotalar joint/talar dome: No subchondral articular surface collapse at this stage. No unstable or displaced fragment. Moderate tibiotalar capsulitis with a small to moderate-sized effusion. No talar shift.

Ankle mortise/syndesmosis: The ankle mortise is in anatomic alignment. No syndesmosis widening.

Chopart joint: Unremarkable.

Midfoot/hindfoot: No fracture or injury of the anterior calcaneal process. No prominent midfoot or hindfoot arthrosis.

LIGAMENTS:

High ankle: Intact.

Low ankle: Intact.

Subtalar/Chopart: Intact.

TENDONS:

Intact.

GENERAL:

Sinus tarsi: Mild diffuse reactive capsulitis. Otherwise unremarkable.

Muscles: No traumatic muscle injury. No volumetric muscle atrophy.

Soft tissue: Unremarkable.

Plantar fascia: Intact.

Neurovascular complex/tarsal tunnel: Unremarkable. No evidence of entrapment neuropathy.

Intra-articular/loose bodies: None.

Impressions

Multifocal avascular necrosis/osteonecrosis as follows:

  1. Extensive talar dome avascular necrosis (greater than 75 % articular surface involvement). No subchondral or articular surface collapse. No unstable or displaced fragment.
  2. Small focus of subarticular avascular necrosis at the talar head.
  3. Focal calcaneal osteonecrosis.
  4. Multifocality consistent with history of leukemia.