Risk factors for renal stone formation in patients with spinal cord injury

To determine factors that may influence kidney stone formation in spinal cord injury patients, the medical records of 893 patients who had been followed up by the Milwaukee Veterans Administration Medical Center from 1970 to 1984 were extensively reviewed. Urography showed that 12 patients had kidney stones. Twenty-four non-kidney stone patients with a similar age range, sex and duration of time since injury were selected as controls. Variables, such as level of spinal lesion, completeness of neurological dysfunction, presence of ureteric reflux etc, were compared and analysed statistically. The results showed that there was no difference between patients with and those without renal stone as far as the level of spinal injury and completeness of spinal cord lesion were concerned. There was no relationship between kidney stone formation and methods of urinary drainage or the presence of ureteric reflux. However, patients with good bladder control had no renal calculi. Serum creatinine, phosphorus, uric acid and calcium levels were similar in both groups of patients. There was a relationship between sepsis, positive urine culture and kidney stone formation. The absence of physical activity was not a risk factor for renal calculi and patients on a high fibre diet had the same incidence of stones as those on a regular diet.