OBJECTIVETo study the differences in clinical outcome of double knee osteoarthritis patients undergoing unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA).

METHODSFrom May 2009 to May 2012, 30 patients (60 knees) with isolated compartmental osteoarthritis of knees were enrolled. Each patient accepted UKA on one knee, TKA on the other. There were 9 male and 21 female patients, aged from 60 to 79 years, average 69 years. Patients evaluation focused on the hospital for special surgery(HSS) knee score, blood loss, hemoglobin 48 h after the operation, the time of knee being able to flex to 90° and patients' sensation after operation. Collection the UKA side and TKA side data and compare two groups of data.

RESULTSAll patients were followed up for 13 to 35 months, average 20.5 months. There were no component loosening and revision. HSS knee score improved significantly in both two groups: UKA group was promoted from 61 ± 3 to 87 ± 3 (t = 11.21, P < 0.001) and TKA group from 59 ± 5 to 86 ± 3 (t = 17.64, P < 0.001). Compared with the TKA group, the UKA group had less blood loss (t = 11.56, P < 0.001), and a decrease of hemoglobin 48 h after the operation (t = 12.38, P < 0.001). The dates of knees being able to flex ≥ 90° after operation were less (t = 4.03, P < 0.05) in the UKA group. As to therapeutic effects, 70% patients found that UKA was better than TKA; 16.7% patients had opposite opinion; and 13.3% patients found no differences between their two knees.

CONCLUSIONSUKA for the treatment of isolated compartmental osteoarthritis of knee shows as well as TKA, and it has less trauma, less blood loss, more rapid postoperative recovery than TKA.