Survivorship of Cemented versus Cementless Total Knee Arthroplasty Using the Same Contemporary Design: A Minimum 5-Year Follow-Up Study.

BACKGROUND

Attention to biologic fixation has been growing in total knee arthroplasty (TKA) over the past years due to the evolution of highly porous metals and improved implant designs. The aim of this study was to assess the minimum 5-year survivorship of a contemporary cementless TKA design, as compared to its cemented counterpart.

METHODS

We reviewed 261 cemented and 222 cementless primary TKAs that were performed at our institution between May 1, 2018, and May 31, 2019, using the same implant design. Demographic data, including age, sex, body mass index, and American Society of Anesthesiologists score, were collected. We assessed survivorship and compared aseptic loosening, all-cause aseptic revision, and all-cause revision rate between groups. The presence of radiolucent lines was also evaluated on the most recent radiographs. Minimum follow-up was five years (mean, 5.8; range, 5.0 to 6.4).

RESULTS

There were four revisions that occurred in the cemented group: two for periprosthetic joint infection, one for patellar maltracking, and one for stiffness. The cementless group had one revision, which involved patellar resurfacing for patellar degeneration. No cases of aseptic loosening were recorded in either group. All-cause revision rate for aseptic reasons was 0.8% in the cemented and 0.5% in the cementless cohort, with no difference between them (P > 0.05). The 5-year all-cause revision survivorship was 98.5% in the cemented and 99.5% in the cementless group. Nonprogressive radiolucent lines were observed in 28 (10.7%) cemented knees and in 22 (9.9%) cementless knees (P > 0.05). No radiographic evidence of component subsidence was identified in either group.

CONCLUSIONS

Cementless fixation TKA demonstrates excellent minimum 5-year survivorship and radiographic outcomes, equivalent to those achieved with cemented fixation. Long-term follow-up is warranted to further assess the durability of cementless implants and determine whether either fixation technique offers a long-term advantage.