Effect of lithotriptor treatment on the fracture toughness of acrylic bone cement.

Extracorporeal shock wave lithotripsy (ESWL) has now been established as an efficacious non-invasive modality for the management of renal calculi and has shown promise for management of other types of stone, as well. Following on from these successes, ESWL has recently been proposed for use in the preliminary stages of revision of cemented total hip joint replacements as a means of breaking up the cement mantle. It is useful, therefore, to examine the effect of shock waves on pertinent mechanical properties of the cement. This study utilizes the chevron-notch short-rod specimen and a commercially available test system to obtain the values of one such property, namely fracture toughness, of Palacos Radiopaque bone cement before and after treatment with shock waves delivered from a lithotriptor. The fracture toughness drops by about 14% following the shock wave treatment, thus confirming the possibility that ESWL can be used, as indicated earlier, in revision arthroplasty.