EARLY RESULTS OF ROBOTIC-ASSISTED CEMENTLESS VERSUS CEMENTED TOTAL KNEE ARTHROPLASTY: MINIMUM TWO-YEAR FOLLOW-UP

Osseous ingrowth of TKA components offers stable biologic fixation, potentially leading to decreased rates of aseptic loosening and increased longevity. Newer implant designs attempt to reduce the complications seen in earlier cementless implants, which were historically plagued by failure. Advancements in robotics over the past decade have allowed for improved accuracy and, in theory, bone-component contact. As surgeons adopt these new techniques, it is important to track performance against the gold standard cemented TKA. Retrospective review of 636 primary TKAs from 2017–2021 performed by fellowship trained arthroplasty surgeons. Group 1 had cement fixation, otherwise the surgical approach, robotic assistance, and intra-operative techniques were the same. Primary outcome was rate of re-operation at 2 years, secondary outcomes were rate of manipulation under anesthesia (MUA) and operative time. Continuous variables compared using unpaired t-tests and categorical variables using chi square tests. A p<0.05 was considered significant. Group 1 had 233 cemented and Group 2 had 403 cementless TKAs. Groups were similar regarding age and medical comorbidities. Minimum follow up was 24 months with an average of 32 months. There were 11 (4.7%) revision surgeries in group 1 and 12 (3.0%) in group 2 (p=0.25) at 2 years. Manipulation under anesthesia was not significantly different; 11(4.7%) vs. 8(2.0%) in the uncemented group (p=0.051). Surgical time was significantly decreased in the cementless group by 12 minutes; 91 vs. 103 min (p=0.02). The optimal fixation method in TKA continues to be debated. Improved implant design along with robotic assistance may offer better osseous integration leading to lower rates of aseptic loosening. This study supports the use of robotic-assisted cementless total knee arthroplasty, showing no significant difference in 2-year reoperation or MUA, and a significantly decreased operative time when compared to cemented TKA. To our knowledge, this is the only study comparing robotic-assisted cementless to cemented TKA. Further longitudinal studies are needed to evaluate differences in long-term outcomes.