UKA revised to TKA, TKA revision yielded similar outcomes
Patients who underwent unilateral knee arthroplasty revised to total knee arthroplasty experienced outcomes similar to patients who underwent revision total knee arthroplasty following primary arthroplasty, despite primary to revision total knee arthroplasty being a more difficult procedure with a higher percentage of re-revisions, according to results.
Utilizing the Norwegian Arthroplasty Register between 1994 and 2011, researchers identified 768 failed primary total knee arthroplasties (TKAs) and 578 failed primary unilateral knee arthroplasties (UKAs) which were revised to TKAs. Patient-reported outcome measures (PROMs) used included the EuroQol EQ-5D, the KOOS and VAS to assess patient satisfaction and pain. To assess the survival rate and the risk of re-revision, researchers performed Kaplan-Meier and Cox regression analyses that adjusted for the propensity score, while multiple linear regression analyses were used to estimate the difference between the groups in mean PROM scores.
Between 1994 and 2011, results showed 12% of patients in the UKA to TKA group and 13% in the primary TKA to revision TKA group underwent re-revision. At 10 years, survival was 82% in the UKA to TKA group vs. 81% in the primary TKA to revision TKA group, according to results. Although researchers found no difference in the overall risk of re-revision for UKA to TKA vs. TKA to TKA or in the PROM scores, patients in the TKA to TKA group older than 70 years of age at the time of revision had a two-times higher risk of re-revision.
Results showed major causes of re-revision for UKA to TKA vs. TKA to TKA included a loose tibial component (28% vs. 17%, respectively), pain alone (22% vs. 12%, respectively), instability (both 19%) and deep infection (16% vs. 31%, respectively). However, researchers noted only deep infection had showed differences between groups and was significantly greater in the TKA to TKA group. Compared with UKA to TKA, TKA to TKA had a longer surgical procedure with more procedures that required stems and stabilization, according to results. – by Casey Tingle
Disclosure: The researchers report no relevant financial disclosures.