Surface flatness after bone cutting. A cadaver study of tibial condyles.

A methodologic study with which the cut surface could be quantified was performed on cadaveric tibial bone prepared for endoprosthetic components. Using sterilized, dental-imprint material and measuring with a Zeiss UMC 850, the characteristics of the cut surface were defined. A clinically flat surface was found to be uneven, with a maximum roughness between the uppermost and lowermost points of 1.0 and 2.4 mm for the bone surface and between 1.2 and 2.3 mm for the imprint. The flatness, defined as the standard deviation of the measuring points, was between 0.15 and 0.40 mm for the bone and 0.20 and 0.42 mm for the imprint. This lack of flatness creates gaps between the prosthesis and the bone.