Spontaneous talar and calcaneal fracture in rheumatoid arthritis: a case report

Abstract

Rheumatoid arthritis (RA) leads to a progressive weakening of the skeleton which may result in bone fractures. However, spontaneous fractures (exclusive of stress fractures, vertebral collapse, and superficial articular fragmentation) in patients with rheumatoid arthritis have been only occasionally reported in the medical literature. A case of spontaneous talar and calcaneal fracture in rheumatoid arthritis is described. Bone lesions were identified on radiographs, MR images and scintigraphy in a patient with right ankle pain. The absence of episodes of acute trauma, and the presence of acute clinical manifestations should guide the clinical suspicion.

Keywords: Rheumatoid arthritis; fracture of the heel; magnetic resonance imaging; spontaneous fracture of the talus; talar and calcaneal fracture.

Figure 1

78-year-old female with RA and spontaneous talar and calcaneal fracture. Lateral view of conventional radiography (a) and magnification view (b) of the ankle showing a subtle radiolucent line in the subtalar region of the calcaneus with cortical disruption. Presence of calcific enthesopathy of the Achilles tendon and of the proximal insertion of the plantar fascia. Regular congruence of visible joints. No pathologic findings are visible in the posterior region of the talus. Presence of a tortuous calicified vessel projecting over the soft tissues posterior to the tibia and ankle (Protocol conventional radiography: 40 kV, 5 mAs)

Figure 2

78-year-old female with RA and spontaneous talar and calcaneal fracture. MR Imaging; FSE and TME sequences. Sagittal and coronal T1 (2a) and axial PD-T2 (2b) -weighted MR images showing irregular, hypointense line of fracture in the subtalar region of the calacaneus, surrounded by a less well-defined area of hypointensity due to bone marrow oedema and hyperaemia (arrow). Presence of irregular hypointense line in the posteroinferior part of the talus extending at the level of the talar neck, compatible with intramedullary bone fracture (arrow head). Muscle tissue, tendons and the other osseous structures present normal signal intensity. (Protocol MRI: 2a. FSE sequence. Sagittal 1,5 Tesla magnet, TR: 640 msec, TE: 14 msec ; Coronal 1,5 Tesla magnet, TR : 440 msec, TE : 12 msec; 2b. TME sequence. Axial 1,5 T, TR : 3440 msec, TE1 : 45 msec, TE2: 102 msec)

Figure 3

78-year-old female with RA and spontaneous talar and calcaneal fracture. MR Imaging; FSE sequences with fat saturation (Fat Sat). Coronal and sagittal T2-weighted images showing hyperintense line in the lower-posterior talus (arrow head) compatible with trabecular bone injury; line of fracture in the upper-anterior calcaneus due to bone fracture, surrounded by a wide hyperintense area related to bone oedema (arrow) more visible in the anterior and sub-talar portion of the calcaneus. Muscle tissue, tendons and the other osseous structures present normal signal intensity. (Protocol MRI: Coronal 1,5 Tesla magnet, TR: 5140 msec, TE: 71 msec; Sagittal 1,5 T, TR: 4560 msec, TE: 75 msec)

Figure 4

78-year-old female with RA and spontaneous talar and calcaneal fracture. Tracer uptake at the right tibio-tarsal region in all phases of the dynamic scintigraphy with an higer radioisotope uptake in the calcaneus. Images related to the third phase of this exam show a wider tracer uptake (4a: blood-pool, seen in anterior view on the left side and in left-lateral view on the right side of the picture; 4b: third phase, seen in anterior view on the left side and in left-lateral view on the right side of the picture). These aspects seem to be related to high osteoblastic and osteoclastic activity after the occurrence of a bone fracture. (Protocol bone scintigraphy: 99mTC-MDP, dose: 740 MBq; images acquired during tracer infusion, after 3 minutes and after 150 minutes)