ObjectiveTo explore whether unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) or bilateral TKAs should be performed in patients with bilateral knee osteoarthritis.MethodsBetween April 2015 and February 2017, 24 patients with bilateral knee osteoarthritis who met the selection criteria were included in the study and randomly divided into 2 groups (n=12). The patients in observation group were treated with TKA of the multicompartmental osteoarthritis knee in the first-stage operation and UKA of the unicompartmental osteoarthritis knee in the second-stage operation; and the patients in control group were treated with bilateral TKAs in staging operation. The operation time, the amount of postoperative drainage, and the time of active flexion of the knee joint at 90° were recorded. The difference of hemoglobin (Hb) before and after the second-stage operation was recorded, and the decrease of Hb was observed. The hospital stay after the second-stage operation was observed. The Hospital for Special Surgery (HSS) score, visual analogue scale (VAS) score, and range of motion (ROM) were recorded at 7 days after the first-stage operation, and at 15 days, 45 days, and 6 months after the second-stage operation. At 1 year after the second-stage operation, the mean values of the above indexes of both knees were taken as the individual comprehensive evaluation. The X-ray films were taken regularly to examine the prosthesis and lower extremity force line. ResultsThe incisions in both groups were healed by first intention after two stage operations. The differences in the operation time, the amount of postoperative drainage, and the time of active flexion of the knee joint at 90° between the two groups were not significant in the first-stage operation (P>0.05) and were significant in the second-stage operation (P<0.05). The decrease of Hb and hospital stay after the second-stage operation were significantly lower in observation group than in control group (P<0.05). Both groups were followed up, the follow-up time was 12-18 months (mean, 14 months) in observation group and 12-21 months (mean, 16 months) in control group. During the follow-up period, X-ray films showed that the prosthesis positions of both sides were normal as well as the alignment line, and no infection, loosening or dislocation of prosthesis occurred. There was no significant difference in HSS score, VAS score, and ROM of multicompartmental osteoarthritis knee at 7 days after the first-stage operation between the two groups (P>0.05), indicating that the two groups were still comparable. The HSS score, VAS score, and ROM of unicompartmental osteoarthritis knee in observation group were superior to control group (P<0.05) after the second-stage operation. At 1 year, the HSS score, VAS score, and ROM in observation group were also superior to control group (P<0.05).ConclusionOn the premise of strict indications, the patients with bilateral knee osteoarthritis should be treated according to their own pathological changes in order to obtain better short-term effectiveness.