The distribution of cement penetration into bovine acetabular bone utilising various pressurisation techniques

Most mechanical failures of acetabular fixation within ten years of primary cemented hip replacement are attributable to a failure to achieve good initial fixation of bone and cement. Several studies have suggested that to achieve good fixation between bone and cement between 3 mm and 5 mm of cement penetration into bone is desirable. Whilst several acetabular cement pressurisation systems exist, little is known about the effects of cement pressurisation on the pattern of penetration of cement into cancellous bone within the pelvis. The current paper assesses the penetration of bone cement into bovine acetabular bone by various pressurisation techniques. We found that pressurisation with the use of a swab in glove or the DePuy pressuriser led to improvement in cement penetration both in terms of maximum depth and also percentage cover of the cup by cement (p<0.05). There was no significant difference in mean maximal penetration between the use of the pressuriser and the swab in a glove technique (p=0.3). If only a plain cup was used as a pressuriser, the penetration achieved was significantly lower in comparison to use of a pressuriser (p<0.02). When compared to previously documented acrylic models, the pattern of intrusion noted in the bovine model was different: penetration was lower at the equatorial and base regions of the acetabulum.