A medial congruent (MC) tibial component has been introduced for the cemented Persona total knee arthroplasty (TKA) that that is designed to closely resembles the functional anatomy of a natural knee in order to provide increased stability and better kinematics. This study aims to evaluate whether the implant design affects implant migration or patient-reported outcome measures (PROMs) in a cemented Persona TKA.
Sixty patients with osteoarthritis were randomised to receive either a MC or cruciate‑retaining (CR) tibial component as part of a primary TKA. Migration was followed for 2 years with radiostereometric analysis, and PROMs were also documented.
At 3 months, mean tibial maximal total point migration was 0.48 mm and 0.56 mm for the MC and CR tibial component, respectively. Two years postoperatively, the corresponding values were 0.62 mm and 0.73 mm. There was no significant difference in migration between groups at any timepoint for any of the translations or rotations measured.
Documented PROMs were the Knee Injury and Osteoarthritis Outcome Score and the Forgotten Joint Score. PROMs improved postoperatively in both the MC and CR groups with no significant difference between groups. To date, there have been no revisions or serious adverse events related to surgery.
The authors of the study conclude “the results are promising, indicating good fixation for both designs, and this is in line with other well‑performing TKAs on the market. The increased medial congruity of the MC inlay does not seem to affect the migration or the PROMs up to 2 years.”