CEMENT PRESSURIZATION DURING HIP-REPLACEMENT

The newer techniques of cementing aim to improve interlock between cem ent and bone around a femoral stem by combining high pressure and redu ced viscosity. This may produce increased embolisation of fat and marr ow leading to hypotension, impaired pulmonary gas exchange and death. For this reason the use of high pressures has been questioned, We comp ared finger-packing with the use of a cement gun by measuring intramed ullary pressures during the cementing of 31 total hip replacements and measuring physiological changes in 19 patients. We also measured pres sure in more detail in a laboratory model. In the clinical series the higher pressures were produced by using a gun, but this caused less ph ysiological disturbance than finger-packing, The laboratory studies sh owed more consistent results with the gun technique, but for both meth ods of cementing the highest pressures were generated during the inser tion of the stem of the prosthesis.