sites of stone impaction

Last reviewed 07/2021

In the kidney important sites of impaction include:

• minor and major calyx system
• pelviureteric junction

In the ureter:

• region of the pelvic brim - where the ureter arches over the iliac vessels
• vesicoureteric junction - the most narrow part of the normal urinary tract

Stones in the bladder are often formed in situ, rather than originating from the upper tracts. Stones that do reach the bladder from the upper tracts are likely to pass easily down the urethra.