Is simultaneous bilateral unicompartmental knee arthroplasty and total knee arthroplasty better than simultaneous bilateral total knee arthroplasty?

INTRODUCTION: This retrospective study aims to clarify if there are benefits of performing unicompartmental knee arthroplasty (UKA) on just one indicated side in patients who undergo simultaneous bilateral knee arthroplasty. MATERIALS AND METHODS: We compared 33 cases of simultaneous bilateral UKA/total knee arthroplasty (TKA) (S-UT) with 99 cases of simultaneous bilateral TKA (S-TT). Comparison included blood tests [C-reactive protein (CRP), albumin, and D-dimer], the incidence of deep vein thrombosis (DVT), range of motion (ROM), and clinical scores before and 1 year after surgery. RESULTS: Clinical scores were not significantly different between the groups. The postoperative flexion angle was significantly better in UKA sides. Blood tests showed that the S-UT had a significantly higher albumin value at 4 and 7 days after surgery. The CRP value at 4 and 7 days, and the D-dimer value at 7 and 14 days after surgery were significantly lower in the S-UT. The S-UT had significantly lower incidence of DVT. CONCLUSIONS: In cases of bilateral arthroplasty, if there is an indication on only one side, a better flexion angle can be obtained by UKA on that side, and with less surgical invasion. Moreover, the incidence of DVT is low, which is considered to be a benefit of performing UKA on just one side.