Hybrid Total Knee Arthroplasty Revisited: Midterm Followup of Hybrid versus Cemented Fixation in Total Knee Arthroplasty

The optimal method of fixation in total knee arthroplasty is still debated. Hybrid total knee arthroplasty (TKA), with cemented tibial and cementless femoral components, is a proposed method of fixation to improve outcomes. Although several studies have shown favorable outcomes, there is still lack of consensus in the literature. We hypothesized that hybrid TKA yields similar clinical, radiographic, and survivorship results compared to fully cemented TKA. The clinical and radiographic outcomes of 304 cruciate retaining TKAs with minimum two-year followup, including 193 hybrid (mean followup of 4.1 years) and fully cemented TKAs (mean followup of 3.2 years) were evaluated. Knee society scores were similar between the two groups. The total number of femoral radiolucencies was also similar between the two groups, while a greater number of femoral Zone 4 radiolucencies were seen in the cemented group (9% versus 1.6%, P = 0.005). The hybrid group demonstrated a 99.2% survival rate of the femoral component out to seven years for aseptic loosening. No significant difference in survivorship was seen between the groups for all cause or aseptic failure at seven years. We conclude that hybrid fixation leads to similar intermediate-term outcomes as fully cemented components and remains a viable option in total knee arthroplasty.