Which Joint is Most Commonly Affected in Gout and What is This Called?
The first metatarsophalangeal (MTP) joint of the great toe is the most commonly affected joint in the initial presentation of gout, occurring in approximately 50% of first attacks, and this presentation is termed "podagra." 1, 2, 3
Clinical Presentation of Podagra
The first MTP joint is affected as the initial site in half of all gout cases, making it the single most characteristic location for disease onset 2, 3, 4
Podagra specifically refers to acute monoarthritis affecting the first metatarsophalangeal joint, though the term literally translates to "seizing the foot" 1
The acute attack typically reaches maximum pain intensity within 6-12 hours, with severe pain, swelling, tenderness, and overlying erythema 1, 5
Why the First MTP Joint?
Multiple factors contribute to the predilection for this joint, including decreased temperature in the foot (which reduces urate solubility), lower pH, physical trauma from walking, and the high prevalence of osteoarthritis in this joint 6
The combination of osteoarthritic changes in the first MTP joint and overnight resolution of synovial effusion creates transient intra-articular hyperuricemia that promotes monosodium urate crystal precipitation 6
Other Commonly Affected Sites
Beyond podagra, gout frequently affects other lower extremity joints including the tarsal and subtalar joints, ankle, and knee 3, 4
Upper extremity involvement includes the wrist, small joints of the hands, and elbow, though these are less common initial presentations 3, 4
Periarticular structures such as the Achilles tendon and olecranon bursae can also be affected 3, 4
Diagnostic Considerations
For typical recurrent podagra with hyperuricemia, clinical diagnosis alone is reasonably accurate (95% strength of recommendation), though not definitive without crystal confirmation 1, 5
Classic podagra has very high diagnostic value with a likelihood ratio of 30.64, sensitivity of 96%, and specificity of 97% 1, 7
However, the term "pseudopodagra" describes first MTP joint inflammation from other causes (septic arthritis, pseudogout, reactive arthritis, trauma), emphasizing that location alone cannot confirm gout 8, 3
Critical Pitfall to Avoid
Never diagnose gout based solely on first MTP joint involvement—always seek crystal confirmation when feasible, particularly for first attacks or when septic arthritis cannot be excluded 1, 5, 8
Joint aspiration with synovial fluid analysis remains the gold standard, with sensitivity of 63-78% and specificity of 93-100% when performed by experienced operators 1, 5