Cementing the tibial component in total knee arthroplasty: which technique is the best?

Objectives: Aseptic loosening of the tibial component remains a major cause of failure in total knee arthroplasty and may be related, directly or indirectly, to micromotion. Therefore, good fixation of the tibial component is a prerequisite to achieve long-term success of the implant. Cementing technique is one of the factors that play a role in this respect. We investigated the effect of different cementing techniques on the cement penetration in the proximal tibia. Methods: We compared 5 different cementing techniques in an anatomical open pore sawbone model (n=25), using a contemporary TKA design and standard polymethylmetacrylate cement. In the first technique, 10 g of cement was applied in a thin layer on the lower surface of the tibial component. The component was then placed and impacted onto the tibia using the specific component impactor supplied by the manufacturer. In the second technique, 20 g of cement was applied in a thick layer on the lower surface of the tibial component. In the third technique, 20 g of cement was applied in equal parts, on both the tibial component and the tibial bone using a spatula. In the fourth technique, 20 g of cement was applied in equal parts on both the tibial component and the tibial bone, but it was fingerpacked into the bone. In the fifth technique, 20g of cement was applied to the tibial bone with the use of a cement gun. After making cuts in the medial and lateral oblique sagittal plane of the tibia, we used Corel PHOTO-PAINT 9 to quantify the cement penetration. Results: Technique 1 (thin layer of cement on the tibial implant only) and 2 (thick layer of cement on the tibial implant only) were not significantly different from each other in terms of penetration depth, but were both significantly different from the other techniques. The same was seen for technique 3 (two equal parts of cement on both the tibial component and the tibial bone using a spatula) and 4 (two equal parts of cement on both the tibial component and the tibial bone, using the fingerpacking technique). The penetration depth was highest for technique 5 (using a cement gun), which was significantly different from all the other techniques. Conclusions: We demonstrated that applying cement to both the undersurface of the tibial baseplate and as well as onto the tibial bone, either by a spatula or fingerpacking technique, leads to an optimal cement penetration of 3-5mm. When cement is applied only onto the tibial component, penetration is insufficient. When a cement gun is used, cement penetration is too excessive.status: publishe