Size distribution characteristics of mineral phase in renal stones.

The size distribution of the mineral phases in three renal stones (whewellite, struvite, and whitlockite) was determined using a particle-counting technique after removal of the organic matrix. The multisized crystallites of the investigated stones revealed close similarity in size distribution characteristics. Whewellite size parameters were in good agreement with the parameters of calcium oxalate monohydrate crystals formed in the kidneys of rats injected with L-4-hydroxyproline. However, these parameters differed significantly from the values calculated from the size distribution of calcium oxalate crystals voided in the urine of recurrent stone formers. The data obtained suggest that critical size distribution characteristics may be instrumental in causing the mineral phase to agglomerate and adopt a close packing in renal stones.