Growth hormone in polymethylmethacrylate cement.

The in vitro release of human growth hormone (hGH) from polymethylmethacrylate bone cement was measured for up to 40 days using a specific enzyme-linked immunosorbent assay. In rabbits, hGH-loaded bone cement was inserted into one distal femur and plain cement was inserted into the contralateral distal femur as a control. The rabbits were killed at time intervals of one, two, and four months after surgery and the distal femurs embedded whole for histology. Quantitative histomorphometry indicated there was a greater percentage of osteoid present at the hGH-loaded cement surface than at the plain cement surface one month after implantation. The hGH released from bone cement may stimulate osteogenesis and new bone formation, thus improving the strength of the bone-cement interface.