The release of gentamicin after total hip replacement using low or high viscosity bone cement. A prospective, randomized study.

Low viscosity bone cement is expected to give improved long term fixation of prosthetic components by increased intrusion into cancellous bone. Fixation is more difficult to achieve after revision for infection because of the inferior quality of the bone. We have compared the amount of gentamicin released from high viscosity and low viscosity bone cements in 41 patients undergoing total hip replacement. The concentration of gentamicin in serum and the wound secretion, and the amount recovered from the urine, was about three times higher for low viscosity cement. A possible explanation for this is an increase in surface area of the cement body because of improved intrusion of cement into bone. The improved mechanical fixation and the high concentration of gentamicin of the bone cement interface favours the use of low viscosity cement, especially in revision for deep infection.