Abstract
Absorbable cement restrictors have been in use over the last few years. They have been shown to be as effective as the standard non-absorbable cement restrictors in achieving cement pressurisation and stopping distal cement migration in in vitro studies. The aim of this study is to compare in vivo, the effectiveness of absorbable with non-absorbable cement restrictors.
One hundred and thirty-six consecutive patients who had total hip replacement performed using charnley cemented femoral prosthesis were selected and randomly divided in to two groups pre operatively. One group received Hardinge TM non-absorbable cement restrictor and the second group received Biostop TM absorbable cement restrictor. Type of the prosthesis, the surgical approach, the time from start of mixing of the cement to insertion of the cement (measure of viscosity of the cement), the cementing technique and the distance at which the cement restrictor was inserted were noted intraoperatively, the canal diameter was measured from the preoperative AP radiograph of the hip. The distance at which the cement restrictor was inserted was measured on the AP radiograph of the hip taken twenty-four hours postoperatively. All the above factors were statistically assessed as to their effect in the distal migration on cement restrictor using multiple regression analysis.
There was no statistical difference between the two types of cement restrictors (P= 0.44). Surgeon, Surgical approach, femoral canal diameter P> 0.2 cementing technique P> 0.1 and Cement viscosity P= 0.082 had no effect on the degree of distal migration of the cement.
In conclusion Biostop TM absorbable cement restrictor is as effective as Hardinge TM non-absorbable cement restrictor. We could not show any relationship between femoral canal diameter cementing technique and cement viscosity and distal cement migration which leads us to conclude that in the presence of adequate cement restriction these factors have little effect in distal migration of cement mantle.
The abstracts were prepared by Nico Verdoschot. Correspondence should be addressed to him at Orthopaedic Research Laboratory, Universitair Medisch Centrum, Orthopaedie / CSS1, Huispost 800, Postbus 9101, 6500 HB Nijmegen, Th. Craanenlaan 7, 6525 GH Nijmegen, The Netherlands.
