What causes joint pain in patients with Sickle Cell Disease?
Patients with SCD or less commonly the heterozygous state (sickle-β thalassemia, S-C, S-D disease) frequently experience polyarthralgias. Local sickling of cells leads to obstruction of the microcirculation and to bone infarctions. During painful crises, patients may experience chest, abdominal, back, muscle, and joint pain caused by microinfarctions. Treatment of painful crises includes hydration, oxygen, and analgesics. Hydroxyurea can reduce the frequency of painful crises. Other musculoskeletal manifestations including painful large joint arthritis (usually the knees) often with noninflammatory synovial effusions lasting a few days to 3 weeks can also occur. These effusions are attributable to bone infarctions causing a “sympathetic” transudative effusion, which is typically unresponsive to intraarticular corticosteroids. Alternatively, some patients during an acute painful crisis will develop a monoarticular or oligoarticular inflammatory arthritis that resolves within a week. Cultures and crystal examinations are negative. Finally, osteonecrosis of larger bones (frequently multifocal) such as the femoral or humeral head is seen in up to 40% of patients with SCD. Initially, radiographs may be normal. MRI is the most sensitive method to detect early osteonecrosis of the bone.
