Different patient satisfaction levels between the first and second knee in the early stage after simultaneous bilateral total knee arthroplasty (TKA): a comparison between subjective and objective outcome assessments

BACKGROUND Simultaneous bilateral total knee arthroplasty (TKA) is an effective treatment option and safe for properly selected patients. The purpose of this study was to evaluate whether patients have different satisfaction levels between the first and second knee in the early stage after simultaneous bilateral TKA. METHODS We retrospectively reviewed 46 patients who underwent simultaneous bilateral TKA by a single surgeon in our department between March 2013 and March 2015. The surgeon typically performed first-side TKA (right knee), followed by TKA on the left knee. Tranexamic acid (TXA) (10 mg/kg) was given intravenously, and the tourniquet was released after wound closure. The preoperative KSS, ROM, and pain visual analog scale (VAS); the objective parameters including drainage volume and swelling evaluated by the circumference of the 10 cm above the patella; and the preoperative and postoperative (1st, 3rd, and 7th days) subjective parameters including pain, satisfaction VAS, and patient satisfaction of the first and second surgeries for each knee were analyzed. RESULTS In simultaneous bilateral TKA, compared with the second-side TKA (left knee), the first-side TKA (right knee) had a lower mean drainage volume (p < 0.05), but the swelling of the knee was higher on the 1st, 3rd, and 7th postoperative days (p < 0.05). Moreover, the first-side TKA was scored lower in satisfaction VAS but higher in pain VAS at the 1st, 3rd, and 7th postoperative days. The patient satisfaction scores indicated 2 (4.4%) of the 46 patients scored first-side TKA higher than second-side TKA, 34 (73.9%) of the 46 patients scored second-side TKA higher than first-side TKA, and 10 (21.7%) of the 46 patients scored their satisfaction as the same for both knees. CONCLUSIONS This research study found that there was better patient satisfaction with the second knee in the early stage after simultaneous bilateral TKA, which may provide some considerations for surgeons choosing simultaneous bilateral total knee arthroplasty for patients with osteoarthritis in both knees.