Mr Mike Rafferty
Podmedics Head of Surgery
Video Duration: 8 minutes
A crystal arthropathy
Gout is a hyperuricaemia and deposition of sodium urate crystals in joint spaces.
Gout occurs in men more than women, due to males having higher uric acid blood levels, however female incidence goes up as diuretics are used. Incidence is mostly in over 50s and has an incidence in the UK of 3-7%
Deposits of sodium urate crystals - Needle shaped
These deposits are in the synovium of joints, most commonly the first metatarsophalangeal joint (The Big Toe). The also affect the hands at the metacarpophalangeal joints and the pinna of the ear.
Uncommon locations for acute gout attacks include the ankle, knee and hip. The cause of increased incidence in lower limbs is thought to be gravitational bias in crystal deposition.
The sodium urate crystals can also from in the kidney and cause chronic nephropathy in severe cases. Renal disease is the most serious complication of chronic gout.
Idiopathic decreased uric acid excretion (commonest)
Impaired excretion due to secondary cause (Thiazide diuretics)
Increased uric acid production
High dietary purine intake
PAIN. Gouty attacks can be very painful. There is acute inflammation around the affected joint with warmth and swelling. It is usually a monoarthritis but more than one joint can be affected.
The nature of the attacks categorises the gout:
Acute - a singular attack with a second attack likely within 2 years
Chronic Interval - chronic gout with acute episodes
Chronic Polyarticular - chronic gout of more than one joint
Tophaceous - a chronic gout that also deposits in soft tissues i.e. the pinna and Achilles tendon
Renal stones - 5% of kidney stones are uric acid stones
(Can be done to check renal involvement)
(Serum uric acid and kidney function)
X - Ray
(Useful in polyarticular as the crystals can calcify)
Joint Fluid Microscopy - exclude concurrent infection
Pain relief - it responds to NSAIDs very well
Change diet to reduce purine intake - cut beer, spinach offal and carbonated drinks
Allopurinol (Xanthine oxidase inhibtor)
Repair or replacement of affected joints usually removal of tophi.