Amyloid arthropathy
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Amyloidosis is defined as the extracellular deposition of the fibrous protein amyloid in one or more sites in the body. Amyloid protein is not filtered by standard dialysis membranes and tends to accumulate within the musculoskeletal system; therefore, amyloid arthropathy is seen in patients undergoing long-term hemodialysis. Amyloid arthropathy may involve the axial skeleton, especially the cervical spine, or the peripheral skeleton. Patients can also develop carpal tunnel syndrome and osteolytic bone lesions (amyloidomas). Shoulder pain and carpal tunnel syndrome are the most common clinical manifestations. Symptoms are commonly bilateral.
Diagnosis
The imaging findings are
- In the glenohumeral joint and other large joints, amyloid arthropathy resembles inflammatory arthritis with juxtaarticular soft-tissue swelling, mild periarticular osteoporosis, and subchondral cystic lesions, usually with well-defined sclerotic margins.
- Usually, the joint space is normal in width until late in the course of the disease.
- Patients with amyloidomas of bone or with large subchondral lesions have a high prevalence of pathologic fractures.
- The MR imaging appearance of amyloid infiltration within or around the joint consists of extensive deposition of an abnormal soft tissue that has low or intermediate signal intensity on T1-weighted images and low to intermediate signal intensity on T2-weighted images.
- This abnormal material covers the synovial membrane, fills subchondral defects, and extends to periarticular soft tissue.
- Joint effusion is usually present.
CT images demonstrate amyloid arthropathy
