The use of bilateral total knee replacements (TKR) is increasing with the number of patients with bilateral end-stage knee osteoarthritis. Bilateral TKR can be performed in three different ways: single-stage, two-team simultaneous bilateral TKR (two surgeons bilateral TKR); single-stage, a sequential bilateral TKR (single surgeon bilateral TKR); and two-stage bilateral TKR. Periprosthetic joint (PJI) infections are serious complications after TKR that negatively affect the aimed outcome, decrease patient satisfaction, and increase morbidity and mortality. The incidence of PJI is 1-2% and the number of cases is projected to grow as the indications for TKR continue to increase. Investigators will prospectively compare the incidence of periprosthetic joint infection between groups.

924 knees (462 participants) will prospectively be randomized into 2 groups: two surgeons bilateral TKA and single surgeon bilateral TKA. While 2 surgeons will perform simultaneous total knee arthroplasty in the two surgeons' bilateral TKA group, one surgeon will perform sequentially in the single surgeon bilateral TKA group. The primary outcome is to compare the incidence of PJI between the groups. Secondary, logistic regression use to estimate the effect of two surgeons bilateral TKA and single surgeon bilateral TKA on the likelihood of a patient being infected.

Inclusion Criteria:

Primary bilateral knee osteoarthritis with refractory to conservative treatment Patients who accept participation in the research and the randomization

Exclusion Criteria:

no history of malignancy without severe extra-articular deformities