Simultaneous bilateral and staged total knee arthroplasty combined with unicompartmental knee arthroplasty in the treatment of bilateral knee osteoarthritis: comparison of early clinical outcomes, complications, and prosthesis survival

Objective Knee osteoarthritis (KOA) is usually bilateral. In many patients, the degree of bilateral knee degeneration varies, with one side involving multiple compartments and the other a single compartment degeneration. Therefore, the objective of this study was to compare the early clinical efficacy of simultaneous bilateral and staged total knee arthroplasty (TKA) combined with unicompartmental knee arthroplasty (UKA) in the treatment of bilateral KOA with different degrees. Methods We compared clinical data from 71 simultaneous bilateral TKA/UKA (SB-TKA/UKA) patients with 52 Staged TKA/UKA (Staged-TKA/UKA) patients. Staged-TKA/UKA is defined as TKA on one knee followed by UKA on the other knee. The comparison included Hospital for Special Surgery (HSS) score, range of motion(ROM), complication rate and prosthetic survival rate at the last follow-up between the two groups. Results The follow-up time of SB-TKA/UKA group was (69.08 +/- 14.35) months, and that of Staged-TKA/UKA group was (73.25 +/- 18.39) months. Staged-KA/UKA group had a shorter hospital stays, less hospitalization costs and shorter operating time (p < 0.001 for hospital stay, p < 0.001 for hospitalization costs and p < 0.001 for operating time). There were no significant differences in HSS and ROM between the two groups at the last follow-up (p > 0.05). There was no significant difference in complication rate between the two groups (chi 2 = 0.56, p = 0.454). For the TKA-side knee joint, there was no significant difference in the prosthetic survival rate (chi 2 = 0.05, p = 0.824) and the prosthetic survival curve (chi 2 = 0.052, p = 0.82) between the two groups. For UKA-side knee joint, there was no significant difference in prosthetic survival rate (chi 2 = 0.08, p = 0.777) and prosthetic survival curve (chi 2 = 0.074, p = 0.786) between the two groups. Conclusions Compared to Staged-TKA/UKA, SB-TKA/UKA has the same early clinical efficacy, shorter operating time and hospital stays, less hospitalization costs, and no increased postoperative complications and prosthesis revision rates. Therefore, SB-TKA/UKA may be recommended for patients who can tolerate simultaneous bilateral surgery as assessed before surgery.