Does Patellar Resurfacing Matter? Midterm Follow-Up of MRK Total Knee Replacement

Background Many designs of TKR have been developed to optimize the kinematics and improve satisfaction, including the ‘medial rotating’ philosophy. The purpose of this study is to report the mid-term clinical outcome of MRK knees and evaluate whether resurfacing the patella makes any difference in outcome. Methods A retrospective analysis was done of 104 MRK total knee replacement done between 2008 and 2017. Patients were called for a review for evaluation of OKS, Baldini and Feller scores. Demographics of the patients, clinical outcome, complications were assessed. Results 62 had patellar resurfacing. Mean follow-up was 74.45 months in non- resurfaced and 54.93 months in resurfaced group. Mean flexion range in both groups at final follow-up was 101.45. Median OKS at follow-up was 36 (12–47) in non-resurfaced and 37 (9–48) in resurfaced group. Patella scores were better in resurfaced group—Baldini score median (range) was 90 (25–100) in non-resurfaced v/s 100 (30–100) in resurfaced, Feller score median (range) was 25 (12–30) in non-resurfaced v/s 28 (10–30) ( p 0.042) in resurfaced. The patellofemoral component of the OKS (Q5 + Q7 + Q12) median showed an improvement from 3 (1–11) to 6.5 (3–11) in non-resurfaced and from 3 (0–12) to 8 (2–12) ( p 0.039) in resurfaced group. There were five complications overall (4.8%). Conclusion These results show a satisfactory outcome at mid-term follow-up. We found a statistically significant difference in Feller score and in the patellofemoral component of OKS between the groups of MRK knee suggesting specific benefits of patellar resurfacing with this implant.