Does a High-Flexion Design Affect Early Outcome of Medial Unicondylar Knee Arthroplasty? Clinical Comparison at 2 Years

Recently, implant companies have sought to target a more active segment of the population with high-flex implants. Our aim was to compare a successful medial UKA implant with its newer high-flex version. Sixty-one patients (nonflex, 33; high-flex [HF], 28) were prospectively followed after medial UKA with a minimum of 2-year follow-up. Patients were evaluated using Short Form 12, Western Ontario and McMaster Osteoarthritis (WOMAC), Knee Society Scores, and range of motion (ROM). The HF group exhibited significantly higher WOMAC Physical Function scores at 3-month follow-up and higher WOMAC Pain and SF-12 Mental Component scores at 2-year follow-up; all other comparisons were not statistically different, including ROM. The HF cohort had significantly higher improvements in Knee Society Function and Knee score at 1- and 2-year follow-up, respectively; all other comparisons yielded no significant differences in mean improvement from baseline, including ROM or survivorship.