Predictive factors for satisfaction after contemporary unicompartmental knee arthroplasty and high tibial osteotomy in isolated medial femorotibial osteoarthritis.

Introduction: Both high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are viable treatment options for early osteoarthritis (OA). Although a substantial proportion of the patient selection criteria for HTO and UKA are now shared, the factors related to satisfaction following each procedure remain unclear.

Hypothesis: We hypothesized that patient factors associated with satisfaction following contemporary HTO and UKA would be different.

Material And Methods: We retrospectively reviewed the records of consecutively enrolled medial opening-wedge HTOs (n=123) and Oxford mobile-bearing UKAs (n=118) with satisfactory postoperative alignment. Preoperative demographics, physical activity levels, varus deformity status, and degree of OA were recorded. Postoperative radiographs, frequency of combined procedures and patient-reported outcomes (PROs) including pain, Western Ontario and McMaster Universities Osteoarthritis Index score, and patient satisfaction were assessed.

Results: Severe OA (p<0.01) was associated with an increased risk of dissatisfaction following HTO, whereas young age (p<0.01) and severe varus deformity (p=0.045) were related to dissatisfaction after UKA. In addition, patient satisfaction following UKA was higher than that following HTO in individuals with highly physically demanding activity. All UKA PROs were superior to those of the HTO group, except pain level.

Conclusion: Despite the shared patient selection criteria for contemporary HTO and UKA, severe OA was associated with dissatisfaction following HTO, whereas young age and varus deformity were associated with dissatisfaction following UKA. Age, varus deformity and OA severity should be considered when deciding whether to perform HTO or UKA.

Type Of Study And Level Of Proof: Retrospective cohort study, Level III.