Ultrasound of the Month – Case 105
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Ultrasound of the Month – Case 105
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Ultrasound of the Month – Case 105
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Diagnosis: Synovial Osteochondromatosis of the Posterior Subtalar Joint Discussion Synovial osteochondromatosis is a proliferative metaplasia of the synovium affecting one joint. Also known as synovial chondromatosis if the lesion is not calcified. Can be a source of slowly progressive joint pain and limited range of motion. Most commonly affects large joints, with the knee being the most frequently involved joint but also occurring in the hip, elbow, and shoulder. On xray and CT, calcified bodies may or may not be seen depending on the degree of ossification. On MRI, synovial osteochondromatosis manifests as hypertrophied synovium which is hypointense on T1-weighted sequences and hyperintense on T2weighted and proton density sequences. Punctate hypointense bodies within the lesion represent mineralized portions of the lesion. On ultrasound, a synovial-based mass showing hyperechoic foci consistent with calcification is suggestive. Surgical resection and synovectomy are curative, although recurrence can occur. Ultrasound of the Month – Case 105
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