RENAL CALCULI. 427 



detected by palpation. In old standing tuberculous disease the 

 kidneys become pyonephrotic and are matted to surrounding 

 structures. Their adhesion to the vena cava inferior on the right 

 side and to the aorta on the left may give rise to considerable 

 difficulty when excision is attempted. 



Renal calculi usually lie in the pelvis of the kidney. The 

 calyces, which are diverticula of the pelvis, have narrow lumina, 

 so a stone lying in a calyx may be well concealed, and may 

 actually become embedded in the renal substance. The con- 

 traction of the pelvis, where it joins the ureter, offers a great 

 obstacle to the passage of calculi, which becoming wedged in the 

 narrow outlet give rise to partial or complete obstruction of the 

 passage. If the obstruction is complete and permanent the 

 kidney becomes atrophic ; if incomplete or recurrent hydro- 

 nephrosis will result. Irritation of the renal pelvis by the stone 

 accounts for the presence of albumen, pus and blood in the urine. 



The kidney lies on the psoas and quadratus lurnborum muscles, 

 and movements which necessitate the action of these muscles will 

 aggravate the pain, or sometimes elicit it if absent. Pain may 

 also be induced by making firm pressure on the front of the 

 pelvis of the kidney. A point on the anterior abdominal wall, a 

 finger's breadth internal to the tip of the ninth costal cartilage 

 fairly indicates the position of the pelvis. This point lies on the 

 transpyloric line. (Fig. 53, p. 419.) Another method of seeking 

 for the presence of calculus is to make forcible percussion of the 

 loin, upwards and inwards, just below the tips of the last two 

 ribs ; this procedure sometimes produces a sharp, darting pain. 



Two varieties of pain may occur with renal calculus, one fixed 

 and localised, and the other intermittent and radiating. The 

 latter is renal colic. The fixed pain is usually in the position of 

 the kidney, but may be referred to some distant spot supplied by 

 a branch of the lumbar plexus. Thus it may be localised in the 

 testicle or the groin, being referred along the genito-crural nerve, 

 in the leg or inner side of the foot being referred to a branch of the 

 anterior crural nerve, or in the domain of the great sciatic nerve 

 posteriorly. The pain of renal colic, on the other hand, shoots 



