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Urolithiasis · Stone TypesUrolithiasis / Infection Stones

Struvite (Infection) Stones

Struvite stones are infection stones — grown by urease-producing bacteria, not by a metabolic abnormality — and curable only by complete surgical removal plus treating the infection.

Orientation

The big picture

Struvite stones are different in kind from the metabolic stones — they are infection stones, grown by bacteria, not by a metabolic abnormality in the urine. That single fact drives everything about how dangerous they are and how they must be treated: because the infection and the stone feed each other, you cannot cure them with medicine alone — every fragment must be removed, or the bacteria living inside the stone regrow it and the kidney is progressively destroyed.

Golden rule

The framework: struvite = magnesium ammonium phosphate, formed only with urease-producing bacteria in alkaline urine, classically forming staghorn calculi, and curable only by complete surgical removal plus treating the infection.

Pathophysiology

Mechanism pathway

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Work-up

Diagnostic algorithm

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Exam

Board traps

Struvite = infection stone (magnesium ammonium phosphate), needs urease-producing bacteria + alkaline urine.

Classic organism is Proteus — ordinary E. coli does not split urea.

Classic cause of staghorn calculi (though not every staghorn is struvite).

Cure requires complete removal of every fragment + treating the infection — antibiotics alone fail because bacteria live inside the stone.

PCNL is the standard for the staghorn/large burden; confirm stone-free.

Test yourself

Quiz

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