Cementation pressure in arthroplasty. In vitro study of cement penetration into femoral heads.

We analyzed the pressure needed for adequate cement penetration into the human arthrotic hip. 85 holes in 39 arthrotic femoral heads were cemented under predetermined pressures and times after cement mixing. Cement penetration correlated well to both pressure and time after mixing. No correlation to the degree of sclerosis was found. At 0.2 MPa, the average penetration into bone was 2 mm. However, 3-5 mm is considered the minimum depth for good fixation of an implant. To achieve a consistent adequate interdigitation, a pressure of approximately 0.3 MPa is recommended.