Knee Function and Flexion Range of Motion in Older Versus Younger Patients Following Simultaneous Bilateral Total Knee Arthroplasty: A Two-Year Retrospective Follow-Up Study

Purpose: To compare knee function and flexion range of motion between older (≥ 70 years) and younger patients ( < 65 years) over a two-year follow-up period following simultaneous bilateral total knee arthroplasty (TKA).Material and Methods: A total of 121 patients were divided into two groups as older (N = 70) and younger (N = 51) patient groups. The groups were compared for knee function (Hospital for Special Surgery (HSS) knee score) and flexion range of motion. The follow-up period was two years.Results: In the HSS knee score, no significant differences were found for the group-by-time interaction (F(5, 573.07) = 1.57, p = 0.18) or the main effect of group (F(1, 114.78) = 1.55, p = 0.21). For knee flexion range of motion, a significant group-by-time interaction was observed (F(5, 572.88) = 3.03, p = 0.01). The older patient group had a significantly lower range of motion preoperatively than the younger patient group (p = 0.02); however, no significant differences were detected at postoperative follow-up time points (p > 0.05).Conclusion: Patients aged 70 and older can benefit from simultaneous bilateral TKA as effectively as their younger counterparts in terms of knee function and flexion range of motion.