Revising an HTO or UKA to TKA: is it more like a primary TKA or a revision TKA?

Forty-nine patients revised from UKA to TKA and 43 from HTO to TKA were matched to 43 aseptic, both component revision TKAs (rTKA) and 97 primary TKAs. At a mean of 4.8 years, the KSS and function scores in the UKA to TKA, HTO to TKA and primary TKA cohorts were similar. Total operative times were significantly higher in the HTO to TKA and rTKA groups. LOS was shorter in the primary TKA cohort. The rate of complications and reoperations were higher in HTO to TKA and rTKA compared to UKA to TKA and primary TKA. Thus, revising an HTO and UKA both had functional outcomes more similar to a primary TKA, however, the complication rate of revising an HTO was similar to an rTKA.