The term gout is derived from the Latin gutta, which means a drop. In the 13th century, it was thought that gout resulted from a drop of evil humor affecting a vulnerable joint.
Gout is a disease in which tissue deposition of monosodium urate (MSU) crystals occurs as a result of hyperuricemia (MSU supersaturation of extracellular fluids), resulting in one or more of the following manifestations:
Tophi (aggregated deposits of MSU occurring in articular, osseous, cartilaginous, or soft tissue areas)
Uric acid nephrolithiasis
Gout is the most common cause of inflammatory arthritis in men over 40 years of age.
Hyperuricemia and gout are strongly associated with obesity and the metabolic syndrome.
Dietary and lifestyle modifications are recommended for the management of gout.
The rheumatologist should always look for gout in all undiagnosed joint conditions even if the serum uric acid level is normal, the involved joint is atypical, and the flare is chronic and polyarticular.
The patient’s comorbid medical conditions should be assessed, including renal and hepatic function, to guide the safest treatment options for acute gout and chronic symptomatic hyperuricemia, with a serum uric acid goal of <6.0 mg/dL.
Joints involved in gout:
The joints of the lower limbs are typically involved more often than those of the upper limbs. The first metatarsophalangeal (MTP) joint of the great toe is involved in >50% of initial attacks and over time is affected in >90% of patients.
Acute gout of the first MTP is termed podagra. In order of frequency of involvement after the MTP joints are the instep, ankle, heel, knee, wrist, fingers, and elbow.
- Joint effusion (earliest sign)
- Preservation of joint space until late stages of the disease
- Absence of periarticular osteopenia
- Eccentric erosions
- Typical appearance “punched-out” erosions with sclerotic margins in a marginal and juxta-articular distribution, with overhanging edges
- Punched-out lytic bone lesions
- Overhanging sclerotic margins
- Avascular necrosis
- Mineralisation is normal
- Surrounding soft tissues
- Tophi: pathognomonic
- Olecranon and prepatellar bursitis
- Periarticular soft tissue swelling due to crystal deposition in tophi around the joints is common
- Soft tissue swelling may be hyperdense due to the crystals, and the tophi can calcify (uncommon in the absence of renal disease)
While there can be variation in appearance, tophi tend to be hyperechoic, heterogeneous, have poorly defined contours. They can be multiple grouped and surrounded by anechoic halos.
Signal characteristics of gouty tophi are usually:
T2: variable, majority of lesions are characteristically heterogeneously hypointense
T1 C+ (Gd): tophus often enhances