Not true about `Struvite Stones’ is –
**Struvite Stones**
### Core Concept
Struvite stones are a type of urinary tract stone composed of magnesium ammonium phosphate (MgNH4PO4·6H2O). They are typically associated with urinary tract infections (UTIs) caused by urease-producing bacteria, such as Proteus, Klebsiella, and Pseudomonas. The presence of urease in these bacteria leads to an increase in urinary pH, creating an environment conducive to the formation of struvite stones.
### Why the Correct Answer is Right
Struvite stones are often formed in the presence of a urinary tract infection caused by urease-producing bacteria. The urease enzyme produced by these bacteria breaks down urea into ammonia and carbon dioxide, leading to an increase in urinary pH. This alkaline environment favors the precipitation of magnesium ammonium phosphate, resulting in the formation of struvite stones. The rapid growth of these stones can lead to obstruction of the urinary tract and potentially life-threatening complications.
### Why Each Wrong Option is Incorrect
**Option A:** Struvite stones are typically radiolucent, making them difficult to detect on plain radiographs. This statement is not necessarily incorrect, but it does not address the specific characteristic of struvite stones being associated with UTIs caused by urease-producing bacteria.
**Option B:** Struvite stones are often formed in the presence of a urinary tract infection caused by urease-producing bacteria. This statement is correct, so it cannot be the answer.
**Option C:** Struvite stones are composed of calcium oxalate. This statement is incorrect because struvite stones are composed of magnesium ammonium phosphate (MgNH4PO4·6H2O), not calcium oxalate.
**Option D:** Struvite stones are typically associated with a low urinary pH. This statement is incorrect because struvite stones are formed in an alkaline environment, typically with a urinary pH above 7.
### Clinical Pearl / High-Yield Fact
It is essential to consider the possibility of a urinary tract infection caused by urease-producing bacteria in patients presenting with struvite stones. A prompt diagnosis and treatment of the underlying infection can help prevent the formation of new stones and alleviate symptoms.
### Correct Answer: C. Struvite stones are composed of calcium oxalate.