This report concerns an operative technique using inexpensive pre-polymerised cement discs as a means of addressing the bone loss from the posterior femoral condyles found during revision total knee replacement. Bone lost from the posterior condyles in the loosened femoral component of a total knee replacement enlarges the flexion gap at revision. Downsizing the femoral component to fit the remaining bone requires a thicker tibial insert and a proximalised new femoral component to maintain balanced gaps in flexion and extension. Patella infera results from this proximalisation of the joint line and interferes with the extensor apparatus. Some knee systems offer customised components with thickened posterior femoral condyles or provide the surgeon with the option of adding metal augments to the femoral component to manage the posterior femoral bone loss. This technique has been applied to ten cases (follow- up ranging from 15 to 46 months) in which inexpensive pre-polymerised cement spacers were incorporated into the posterior femoral cement mass. This allowed the use of primary stemmed components with preservation of the original joint line position. No case has resulted in loosening although two cases have required further revision due to recurrence of their original infection. At revision of these cases the cement discs remained firmly incorporated in the cement mass. We conclude that this technique is reliable, inexpensive and could be applied to other prosthetic varieties.
