Cement compression device for cemented total knee arthroplasty

Aims: Optimal fixation of the tibial component is crucial to prevent aseptic loosening in total knee arthroplasty (TKA). This involves cement penetrating the tibia by 3 mm to 4 mm. Cement application is not standardized, and ideal penetration depth is not achieved frequently. Therefore, a cement compression device (CCD) was developed. The CCD is positioned around the tibial component, prevents cement leakage, and compresses cement into the tibia. It is hypothesized that the CCD enhances cement penetration and distribution in TKA. Methods: Patients were randomized into two groups: cement application using the finger-packing technique or the CCD. A CT scan was performed postoperatively to determine the percentage of cemented surface (PCS) per quadrant in the proximal tibia, up to 7 mm from the tibial baseplate. Differentiation between bone, cement, and prosthesis on the CT scans was performed using a previously validated method in MATLAB, based on differences in Hounsfield units. PCS was compared per quadrant for the mean of 3 mm and 4 mm depth slices and for each millimetre up to 7 mm depth. Additionally, operating time was compared. Results: In 16 patients, the finger-packing technique was used and in 16 patients, the CCD. In the anterolateral and posterolateral quadrants, PCS was 54% in the finger-packing group versus 72% in the CCD group (95% CI -28.85 to -8.17; p < 0.001), and 34% versus 46% (95% CI -22.78 to -2.05; p = 0.025), respectively. In the posteromedial quadrant, PCS was 28% versus 39% (95% CI -22.39 to -0.15; p = 0.047). In the anteromedial quadrant, PCS was higher in the CCD group, but the difference was not significant. Operating time was 66 minutes in the finger-packing group, compared with 68 minutes in the CCD group (95% CI -8.0 to 3.4; p = 0.416). Conclusion: The CCD results in improved cement penetration and distribution in TKA at the mean of 3 mm to 4 mm and reaching up to 7 mm depth from the tibial baseplate. Implementing the CCD does not prolong the procedure.