Experimental investigation of negative pressure intrusion techniques of acetabular cementation in total hip arthroplasty.

The main mode of failure of the acetabular component in total hip arthroplasty is aseptic loosening. Successive generations of cementation techniques have evolved to alleviate this problem. This paper evaluates one such method, Negative Pressure Intrusion Cementation. Two groups of machined bovine cancellous bone samples were created; experimental (n = 26) and control (n = 26). The experimental group was cemented using the negative pressure technique and the control group was cemented in the absence of negative pressure. The relative cement intrusion depths were then assessed for each group using MicroCT. These samples were then further machined and tested to failure in torsion to estimate their mechanical properties. Results show mean cement intrusion depth for the negative pressure group to be 8,676 microm and 6,042 microm for the control group (p = 0.078). Mechanical testing revealed a greater mean torque in the negative pressure group (1.6223 Nm versus 1.2063 Nm) (p = 0.095). This work quantifies the effect of negative intraosseous pressure on cement intrusion depth in cancellous bone and for the first time relates this to increased mechanical strength.