Summary

Inverse kinematic alignment in robotic-assisted total knee replacement is an optimal choice for a better clinical outcome and a longer implant survivorship.

Abstract

Objectives: Despite advancements in total knee arthroplasty (TKA) surgical technique and implant geometry, some patients still report dissatisfaction with their knee implant. Consequently, the introduction of new robotic-assisted systems aims to improve clinical outcomes through a comprehensive study of patient lower limb alignment. The purpose of this study is to investigate whether the surgical technique of inverse kinematic alignment using a robotic-assisted system (Mako, Stryker) can provide a better clinical outcome and a longer implant survivorship.

Material And Methods

From January 2022 to December 2023, two surgeons performed 106 robot-assisted inverse kinematic alignment TKAs and these were prospectively evaluated. The clinical outcome has been evaluated preoperatory and at 6 months through the Knee Society Score (KSS) and the Knee Injury and Osteoarthritis Outcome Study (KOOS). Implant survivorship has been grouped at 6, 12 and 24 months post-surgery.

Results

Clinical parameters at 6 months postoperative yielded statistically significant results: KSS scored 93±5 points with p=0.03, and KOOS scored 87±7 points with p=0.16174. Implant survival was estimated at 100% (p=0.087) 6 months postoperatively and 98.94% (p=0.972) both after 12 and 24 months, with only one patient undergoing a second surgery due to aseptic loosening.

Conclusion

Compared to the literature, the results of the study have reported comparable clinical outcomes at 6 months, while implant survival has been longer throughout the entire examined period. In the near future, our objective will be to assess this same patient group with a complete 2-year follow-up. In summary, inverse kinematic alignment for TKA using a robotic-assisted system represents the gold standard in our experience, both in terms of implant survival and patient satisfaction.