UKA Superior to HTO in Functional Outcomes for Medial Knee OA: Study

Saurav Narayan Nanda et al conducted a study to compare functional and radiographic outcomes between medial opening-wedge high tibial osteotomy (HTO) and medial unicompartmental knee arthroplasty (UKA) in isolated medial compartment osteoarthritis, incorporating minimal clinically important difference (MCID) thresholds for clinical interpretation. The article has been published in ‘Indian Journal of Orthopaedics.’

A retrospective propensity score-matched cohort study of 52 patients (26 HTO, 26 UKA) was performed. Outcomes included Oxford Knee Score (OKS, primary), VAS pain, Knee Society Score (KSS) Function, radiographic alignment, complications, and revision-free survival.

The key findings of the study were:

• Baseline characteristics were well-balanced in the study of 52 patients, evenly divided between high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA), with a mean follow-up of 28.4 ± 4.2 months.

• There were no significant differences in preoperative varus deformity (9.2° ± 1.9 vs. 8.9° ± 2.0, p = 0.61), BMI (26.9 ± 2.5 kg/m 2 vs. 27.3 ± 2.7 kg/m 2 , p = 0.63), or age (53.4 ± 4.7 years for HTO vs. 55.2 ± 5.1 years for UKA, p = 0.29).

• At a mean follow-up of 28.4 ± 4.2 months, baseline characteristics were balanced.

• UKA achieved superior OKS at 24 months (40.1 vs. 34.8, mean difference 5.3, p = 0.001), exceeding the MCID threshold.

• Pain reduction favored UKA but did not reach MCID (mean difference 1.1, p = 0.002). KSS Function differences were statistically significant but below MCID.

• Radiographic correction was greater with HTO (valgus 3.9° vs. 0.9°, p < 0.001).

• Revision rates were 3.8% for HTO vs. 7.7% for UKA (p = 0.55).

The authors concluded – “In patients with isolated medial compartment osteoarthritis, unicompartmental knee arthroplasty showed a clinically significant improvement in functional outcomes at the 2-year follow-up, as determined by the Oxford Knee Score, when compared to high tibial osteotomy. Differences in pain and Knee Society Score Function were statistically significant but did not reach clinical thresholds. High tibial osteotomy provided superior mechanical axis correction and remains a valuable joint-preserving procedure, particularly for younger and more active patients. Surgical decision-making should, therefore, be individualized, balancing patient age, activity demands, and expectations.”

Level of Evidence: III (retrospective cohort study).

For further details on the article refer to:

Medial Unicompartmental Knee Arthroplasty vs. High Tibial Osteotomy for Isolated Medial Knee Osteoarthritis: A Propensity-Matched Study of Clinical Outcomes

Saurav Narayan Nanda et al

Indian Journal of Orthopaedics (2026) 60:458–464

https://doi.org/10.1007/s43465-025-01608-x