ALUMINUM LEVELS AND STORES IN PATIENTS WITH TOTAL HIP ENDOPROSTHESES FROM TIAIV OR TIAINB ALLOYS

Aluminum ranks as a potentially hazardous agent. Pathologic findings i n different organs show that it can accumulate in brain, muscle, liver and bone. Therefore, we investigated whether patients with cementless total hip endoprostheses made out of titanium alloys containing alumi num are at risk. In order to determine the complete aluminum body load ing in patients who have had their hip replacement for a long period o f time (mean 58 months), we mobilized possible stores of aluminum with desferoxamine (DFO). Electrothermal atomic absorption spectroscopy wa s used to quantify the level of aluminum in serum and urine before and after DFO treatment. A serum aluminum value of 10 mu g/l or less is i nternationally accepted as safe. The average serum aluminum level in t his study was 14.2 mu g/l, which is slightly above the limit, but clea rly below those levels which can lead to disease (> 50 mu g/l). No rel evant storage of aluminum was found. This latter finding is more impor tant since chronically elevated aluminum levels lead to cellular depos its, which affect the cellular biochemistry. The values before and aft er DFO mobilization did not differ substantially, indicating that alum inum in alloys for biomaterials can be regarded as safe as far as the risk of aluminum release in vivo is concerned. Histologic studies of b one from the bone-metal interface also showed no deposits of local alu minum release.