Patient History
19 F with lateral and anterior/dorsal ankle pain, swelling, decreased ROM
Findings
Osseous Structures: No fracture or dislocations noted. No intramedullary lesions. The medial and lateral malleoli are intact. No osteochondral injuries of the tibial plafond or talar dome. No posterior or mid talar arthrosis. Midfoot without arthropathy. Normal Lisfranc joint.
Ligaments: The lateral low ankle ligaments (anterior talofibular, posterior talofibular and calcaneofibular) and high ankle ligaments including the anterior tibiofibular, posterior tibiofibular and syndesmosis are intact. The deltoid ligament complex is intact.
Muscles/Tendons: Peroneus muscles, extensor and flexors without evidence of tendinopathy, tenosynovitis, tears or myositis.
Soft Tissues: Lobulated intermediate to low T1 and T2 signal intensity intraarticular lesion located in the hindfoot adjacent to the posterior talar process at the subtalar joint measuring 2.4cm x 3.2cm x 1.6cm (AP, transverse and CC).
The plantar fascia is without thickness. No evidence of traction enthesophyte at the calcaneal tuberosity. No inflammatory changes or tears. The heel fat pad is without edema.
Neurovascular: Tarsal tunnel and its contents are normal. No space-occupying lesions within it.
Moderate tibiotalar and subtalar joint effusion without reactive synovitis. Mild periarticular soft tissue swelling.
Impressions
1. Lobulated “frond-like” intraarticular lesion with low T1 and T2 signal intensity containing hemosiderin deposits located in the hindfoot adjacent to the posterior talar process measuring 2.4cm x 3.2cm x 1.6cm (AP, transverse and CC) representing pigmented nodular synovitis (giant cell tumor of the tendon sheath). No osseous erosions.
2. Moderate tibiotalar and subtalar joint effusion without reactive synovitis.
3. No osseous, ligamentous or tendinous injuries.
