In vitro evaluation of bonding of the cement-metal interface of a total hip femoral component using ultrasound.

Abstract

Debonding of the cement-metal interface of a cemented femoral component is one mechanism associated with loosening of total hip replacement. An ultrasonic pulse-echo technique was developed to determine, nondestructively, the integrity of the cement-metal interface in vitro. The characteristics of the ultrasonic reflections of bonded and debonded interfaces were obtained by using a physical model that consisted of a flat slab of cement and a flat cobalt alloy plate with known conditions of bonded and debonded interfaces. The same model was used to establish that the ultrasonic technique could distinguish between two surfaces that were in direct opposition but not bonded and those that were actually bonded. This technique then was shown to be useful in nondestructively detecting bonded and debonded cement-metal interfaces of femoral prostheses cemented into fiberglass femurs and femurs from human cadavera.