At. Brooks et al., MINIMAL FEMORAL CORTICAL THICKNESS NECESSARY TO PREVENT PERFORATION BY ULTRASONIC TOOLS IN JOINT REVISION SURGERY, The Journal of arthroplasty, 10(3), 1995, pp. 359-362
Ultrasonic tools are effective in removing cement in revision surgery
and almost eliminate perforation of the femoral shaft, a dangerous com
plication associated with cement removal using drills, chisels, osteot
omes, and other tools. Clinically, the ultrasonic tool used to remove
cement could not be passed through a relatively normal femoral cortex;
however, a perforation occurred in a patient with a femoral cortex le
ss than 1 mm thick. The purpose of this study was to determine how thi
n the femoral cortex can be and yet allow the safe use of ultrasonic t
ools to remove cement without the risk of perforation. A cement mantle
was constructed in the intramedullary canal of human cadaver femurs.
Each specimen was mounted on a jig, which was then fastened to a Mater
ials Testing System (Minneapolis, MN). The average load generated acro
ss the cortex by the ultrasonic tools while removing cement was measur
ed. Loads of varying magnitudes were then applied by the ultrasonic to
ols to femoral cortices of varying thickness. When the cortex measured
3 mm thick, perforation did not occur. When the cortex measured 2 mm,
perforation was possible but required loads three to six times greate
r than those normally used to remove cement.