DETRIMENTAL EFFECT OF AGING ON THE ENDURANCE OF BONE-CEMENT - AN IN-VIVO AND IN-VITRO STUDY IN RABBITS

We investigated the effect of aging on the compressive strength of bon e cement under in vivo and in vitro conditions. Cement molds were impl anted in the dorsum of rabbits and other molds were kept under stable conditions and in darkness. Comparative pressures taken at 15 days and 1, 3, 6, 12 and 24 months showed lower endurance of the implanted mol ds (p<0.001). A reactive capsule surrounded the bone cement in vivo up to the 3rd month, its cellularity increased, and then almost disappea red by 1 year. Macrophages and foreign body cells reappeared at 2 year s, indicating a ''chemical aging'' effect in the in vivo environment. Our findings suggest that aging may play an important role in the amel ioration of the mechanical properties of bone cement.