Bony sequestrum: a radiologic review.

According to a pathological definition, a bony sequestrum is defined as a piece of devitalized bone that has been separated from the surrounding bone during the process of necrosis. However, the radiological definition of a sequestrum is different and refers to an image of calcification visible within a lucent lesion, completely separated from the surrounding bone, without referring to the vascular status and histological nature of the calcified tissue. The term "button sequestrum" has been used in calvarial lesions. The prototype conditions that may present with a bony sequestrum are osteomyelitis and skeletal tuberculosis. Other conditions such as radiation necrosis, eosinophilic granuloma, metastatic carcinoma, primary lymphoma of bone, aggressive fibrous tumors may also manifest as osteolytic lesions containing a sequestrum. In addition, some primary bone tumors produce a matrix that may mineralize and sometimes simulate a bone sequestrum. These include osteoid tumors (osteoid osteoma, osteoblastoma), cartilaginous tumors (chondroma and chondroblastoma), lipomatous tumors (lipoma), and benign fibrous tumors (fibromyxoma, myxoma, and desmoplastic fibroma). Therefore, various conditions may present at imaging as a small area of osteolysis containing central calcifications. However, a careful analysis of the sequestrum as well as the associated clinical and radiological findings often enables to point toward a limited number of conditions.

Use of infliximab to treat psoriatic arthritis in HIV-positive patients.

Psoriatic arthritis in HIV-positive patients is not only severe, but also raises specific treatment challenges, as immunosuppressant and immunomodulating agents may adversely affect both the course of the HIV infection and the risk of opportunistic infections. TNFalpha antagonists have not been evaluated in patients with HIV infection, which is therefore considered to contraindicate their use. Two HIV-positive patients with psoriatic arthritis unresponsive to methotrexate alone were treated with infliximab (5 and 2 mg/kg, respectively), methotrexate, and antiretroviral drugs. Dramatic improvements in the skin and joint manifestations occurred in both patients. Tolerance was good, after follow-ups of 24 and 50 months, respectively. No opportunistic infections occurred. Viral load remained well controlled and CD4+T-cell counts stable, although both patients required adjustments in their antiretroviral regimens based on close monitoring of these two parameters. HIV infection classically contraindicates the use of TNFalpha antagonists to treat refractory inflammatory joint disease. However, exceptions to this rule can be made in carefully selected patients who have exhausted all other treatment options for their joint disease and who respond well to antiretroviral therapy. Potential long-term effects such as opportunistic infections, malignancies, and loss of HIV control need to be evaluated.