Is a high tibial osteotomy (HTO) superior to non-surgical treatment in patients with varus malaligned medial knee osteoarthritis (OA)? A propensity matched study using 2 randomized controlled trial (RCT) datasets.

Objective: No randomized controlled trial (RCT) has compared the high tibial osteotomy (HTO) with non-surgical treatment in patients with medial knee osteoarthritis (OA) and varus malalignment. The aim was to compare the effectiveness of an unloader brace treatment or a usual care program to the HTO regarding pain severity and knee function.
Design: Surgical treatment (HTO) to two non-surgical options was compared by combining the data of two RCTs. One RCT (n = 117) compared an unloader brace to usual care treatment; the other RCT (n = 92) compared closing to opening wedge HTO. One-to-many propensity score matching was used to equalize patient characteristics. We compared clinical outcome at 1 year follow-up (VAS pain (0-10) and knee function (HSS, 0-100)) with mixed model analysis.
Results: Propensity score matching resulted in a comparison of 30 brace patient with 83 HTO patients, and of 28 usual care patients with 71 HTO patients. Pain at 1 year after HTO (VAS 3.8) was lower than after valgus bracing (VAS 5.0) with a mean difference of -1.1 (95% CI -2.2; -0.1). Function showed a nonsignificant mean difference of 2.1 [95% CI -3.1; 7.3]. Comparing HTO to usual care a difference was seen in pain (-1.7 [95% CI -2.8; -0.6]) and function (6.6 [95% CI 0.2; 13.1]), in favor of the HTO.
Conclusions: Our data suggest that HTO was more effective in pain reduction compared to both non-surgical treatments. Function improved only when HTO was compared to usual care treatment. These small differences question the benefits of surgical treatment over the brace treatment.
(Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)