There Were No Differences in Total Knee Arthroplasty Function Following High Tibial Osteotomy or Unicompartmental Knee Arthroplasty: More Than 10 Years of Follow-Up.

Background

In the United States (U.S.), unicompartmental knee arthroplasty (UKA) is more widely adopted than high tibial osteotomy (HTO) as treatment for medial knee osteoarthritis. Both procedures may ultimately require conversion to total knee arthroplasty (TKA). However, outcomes of TKA following prior HTO or UKA remain incompletely characterized in the U.S. POPULATION Therefore, this study evaluated revision-free survivorship and clinical outcomes of TKA following prior ipsilateral HTO or UKA in a U.S. COHORT

Methods

We prospectively followed 216 patients who underwent TKA after ipsilateral HTO (n = 134) or UKA (n = 82) between 2000 and 2023 at a single U.S. center, who had a mean follow-up of 11.5 years (range, zero to 24.0) after TKA. Data included demographics, comorbidities, implant characteristics, revision surgery, all-cause reoperations, Knee Society Scores (KSS; minimal clinically important difference six points), and range of motion. Kaplan-Meier and Cox proportional hazards analyses were used to compare revision-free survival, infection rate, and reoperation rate between cohorts.

Results

Revision, infection, and all-cause reoperation rates after TKA were similar in both cohorts (revision: 4 versus 6%, P = 0.91; infection: 4 versus 2%, P = 0.27; all-cause reoperation, P = 0.34). The UKA-TKA procedures more frequently employed stemmed tibial (71 versus 15%, P < 0.001) and femoral components (21 versus 5%, P < 0.001) than the HTO-TKA cohort, although HTO-TKA procedures had a significantly longer surgery time (133.5 versus 102.0 minutes, P < 0.001). The HTO-TKA patients had significantly higher KSS functional scores at two years (median difference 15 points, P < 0.001) and five years (median difference 10 points, P = 0.04) compared to UKA-TKA.

Conclusion

In this U.S. cohort, TKAs following prior HTO or UKA showed no statistically significant differences in revision rates, infection, or all-cause reoperation. Operative time was significantly longer for TKA after HTO, whereas TKA after UKA more frequently required stemmed components. Overall, these findings suggest no statistically significant differences in outcomes or survivorship between prior HTO and the widely adopted UKA, supporting HTO as a viable joint-preserving option in appropriately selected patients.