The Influence of Restricted Instrumented Kinematic Alignment versus Navigated Assisted Kinematic Alignment in Total Knee Replacement

Background:
Mechanical alignment (MA) in TKA significantly improves function, satisfaction and has long track record with excellent survivorship. Nevertheless, a high percentage of patients are not satisfied after TKA (total knee arthroplasty). Moreover, none of the efforts performed to achieve higher accuracy in component positioning, such as computer-assisted surgery, have resulted in better outcomes. In contrast, several authors report improved outcomes after slightly under correcting varus knees after TKA in comparison with neutral alignment.

Methods:
This double blinded, prospective randomized controlled study, will include 120 patients undergoing TKA for primary osteoarthritis. We performed restricted kinematic alignment (rKA) for all the patients. Patients are randomized into one of four groups. Navigated assisted group, instrumented technique group and each group is further divided into two types of implants: medial pivot (MP) and cruciate retaining (CR). Data is collected by a blinded intern using PROM questionaries: PROMIS, EQ5D, KOOS, OKS, FJS. A blinded physiotherapist collected physical data: ROM, time up and go (TUG). Patients will be followed for 5 years.

Results:
We will be presenting our preliminary results of 3 months FU on the first 80 patients.