Disruption of the blood supply to the talar dome leads to bone infarction that may be segmental or involve the entire dome. There is ischemic death of the cellular constituents in the infarcted area, which leads to osteonecrosis. Histologically, this process is recognized on the basis of the disappearance of osteocytes from within the lacunae. Radiographs give the appearance of osteoporosis of the surrounding bone due to hyperemia, whereas the infarcted bone retains its density. Disruption of the blood supply can be secondary to trauma6,12,14,20, external compression, or intraluminal obstruction1,3. Disruption due to external compression can occur when a space-occupying lesion physically compresses the arterial supply and inhibits blood flow. Intraluminal obstruction occurs when there is an intravascular process that interrupts blood flow. Fat emboli can occlude blood vessels; this has been seen in histological studies performed on specimens of osteonecrotic femoral heads3.
Osteonecrosis of the talus has also been reported in association with several nontraumatic factors, such as exposure to pressurized atmospheric conditions, the use of corticosteroids, alcoholism, sickle-cell disease, chronic pancreatitis, Cushing disease, Addison disease, peripheral vascular disease, and dialysis for chronic renal failure1,3,9,10,13,17. There have also been reports of osteonecrosis of the entire body of the talus after a triple arthrodesis when there has been extensive resection of the talar head and neck4,8,15,18. We report the occurrence of osteonecrosis of the lateral aspect of the talar dome after a triple arthrodesis in three patients who had rheumatoid arthritis and had been taking corticosteroids.
CASE 1. A sixty-eight-year-old man who had seropositive rheumatoid arthritis, diagnosed in 1976, was first seen by us in 1992 …
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