Comparison of Cement Penetration and Clinical Outcomes in Total Knee Arthroplasty: High-Viscosity vs Low-Viscosity Cement

This retrospective study compared cement penetration, the radiolucent line (RLL) incidence, and clinical outcomes in total knee arthroplasty (TKA) using high-viscosity cement (HVC) versus low-viscosity cement (LVC) with a minimum follow-up of two years. We hypothesized that LVC would result in superior cement penetration and a reduced RLL incidence compared with HVC without differences in clinical outcomes. A total of 100 patients (50 HVC, 50 LVC) who underwent TKA with the same implant design were included. Cement penetration was assessed in four tibial and two femoral zones. Clinical outcomes including the VAS, WOMAC, KSS, KOOS and FJS were evaluated preoperatively and at the final follow-up visit. Postoperative complications were recorded. LVC demonstrated significantly greater cement penetration in the posterior tibial zone (3.03 mm vs. vs 2.82 mm; p=0.005) and posterior femoral zone (1.76 mm vs. 1.39 mm; p<0.000) than HVC, and no differences were observed in other zones. The RLL incidence and rates of complications including aseptic loosening and prosthetic joint infection were comparable between groups. Both groups showed significant postoperative improvements in the WOMAC, KSS, and KOOS, with no intergroup differences preoperatively and postoperatively. LVC demonstrated superior cement penetration in select zones, which may enhance implant fixation. However, there were no differences in the RLL incidence or clinical outcomes between the HVC and LVC groups. Both cements provided satisfactory fixation and clinical results, suggesting that either may be appropriate based on surgical preferences and fixation goals.