Objective  To compare the clinical effectiveness and safety between simultaneous and staggered bilateral total knee arthroplasty(TKA) in one hospitalization.

  Methods  We retrospectively analyzed 233 patients with primary osteoarthritis of both knee joints who received bilateral TKA in one hospitalization and follow-up for at least 2 years. These patients were grouped into simultaneous group and staggered group based on the procedures they received. The age, body weight index(BWI), years lived with disorder(YLD), pre-operative co-morbidity, pre-operative hospitalization time, total hospitalization time, total operation time, total toniquet time, total drainage volume, total blood transfusion volume, pre-operative Hospital for Special Surgery(HSS)score, post-operative HSS score(2 years), complications, and its ratio were reviewed and analyzed with one tail t test.

  Results  The simultaneous group included 191 cases(31 males and 160 females) and the staggered group included 42 cases(5 males and 37 females). The pre-operative co-morbidity rate was significantly higher in the staggered group than in the simultaneous group, while no such significant difference existed in terms of age, BWI, and YLD(P>0.05). The total hospitalization time of staggered group was significantly longer than that in the simultaneous group, while the total blood transfusion volume was significantly less(both P < 0.01). The pre-operative hospitalization time, total operation time, total toniquet time, and total drainage volume were not significantly different between these two groups(P>0.05). The HSS scores before operation and 2 years after operation were also not significantly different(P>0.05). The wound complication rate was higher in the simultaneous group than the staggered group. Thromboembolism events occurred only in calf muscular veins in both groups with similar incidences. No patients suffered from severe complication or died during hospital stay.

  Conclusion  With reasonable patient selection and delicated pre-operative preparation, simultaneous bilateral TKA has similar clinical effectiveness and safety as staggered bilateral TKA.