Radiographic features in Reactive Arthritis
Remember your ABCDE’S. These radiographic features are typical of all seronegative spondyloarthropathies.
A — A nkylosis of the spine occurs in up to 20% to 25% patients. There are large nonmarginal syndesmophytes called “jug-handle” syndesmophytes, which usually occur in an asymmetric distribution. These syndesmophytes can also occur in psoriatic spondylitis but differ from the thin, marginal, bilateral syndesmophytes seen in ankylosing spondylitis
B — B ony reactivity and proliferation at enthesis sites (Achilles tendon and plantar fascia insertions) and periostitis are common. Ossification of tendons may occur. Bone demineralization (periarticular osteopenia) may be observed.
C — C artilage space narrowing occurs uniformly across the joint space of weight-bearing joints compatible with an inflammatory arthritis. No soft tissue calcifications are seen.
D — D istribution of arthritis is primarily in the lower extremity, whereas psoriatic arthritis usually affects the upper extremity. The sentinel joint involved may be the interphalangeal joint of the great toe
E — E rosions are common in the metatarsophalangeal joints. Sacroiliac joint erosions tend to involve one joint more than the other (asymmetric), which contrasts to the symmetric involvement of ankylosing spondylitis
S — S oft tissue swelling and dactylitis (diffuse swelling of toes).