To compare the effects of pulsed lavage versus bulb syringe irrigation on cement penetration into metaphyseal cancellous bone.

Bone slabs, about 1 cm in thickness, taken from the distal metaphysis of 10 femurs of adult pigs were used. Slaps were sectioned in the sagittal and transverse planes, and divided into two groups. One half of the specimens was irrigated with saline by pulsed lavage, while the other half was irrigated with saline using bulb syringes. Bone cement was pressurized into the cut surface using a cement gun. Trimmed bone blocks were fixed in formaldehyde, dehydrated in ethanol, and embedded in plastic resin (Spurr's low-viscosity medium). Contiguous sectioning was done and the sections surfaces were ground. The depth of cement penetration, and the total area of cement-bone interdigitation were analyzed using image analysis software.

The average total area of cement-bone interdigitation was 34.9 mm2 in the pulsed lavage group and 20.2 mm2 in the bulb syringe group. The average penetration depth of cement was 4.4 mm in the pulsed lavage group, and 2.5 mm in the bulb syringe group.

The penetration of cement during arthroplasty is significantly increased by pulsed lavage, which could reduce late complications and aseptic loosening.