High-Viscosity Versus a Lower-Viscosity Cement Penetration at Dough Phase In Vivo in Primary Total Knee Arthroplasty

Previous studies have shown that the depth of cement penetration and the presence of radiolucent lines (RLLs) correspond with the risk of aseptic loosening in total knee arthroplasty, while others have found a correlation between the viscosity of the cement and the depth of cement penetration. We compared cement marketed as high-viscosity cement (HVC) with one marketed by the same manufacturer as low-viscosity cement (LVC). We hypothesized that no significant difference would be found in depth of penetration or presence of RLLs between the two cohorts.

The HVC (n = 50) and LVC cohorts (n = 50) were gathered from two sequential series of primary total knee arthroplasties using the same implants and cementing techniques. Depth of cement penetration and presence of RLL were measured in four tibial zones and were compared between cohorts.

There were no cases of aseptic loosening in either cohort at a mean of 29 months. Mean maximum cement penetration in 3 of the 4 zones was >3 mm with both cements. There was no significant difference in maximum penetration in any zone between the two cements. There were fewer tibial radiolucencies with HVC than LVC.

These findings suggest that the marketing description of HVC or LVC is not necessarily a factor in cement penetration. The term high viscosity should not be used as a descriptor of cement that reaches dough phase more quickly, but rather cement that has a higher viscosity at its dough phase when it is typically applied.