# Knee extensor strength normalised to body weight is associated with patient‐reported outcomes at 12 months after open‐wedge high tibial osteotomy

## TL;DR

Stronger knee extensor muscles relative to body weight are linked to better patient outcomes 12 months after a specific knee surgery.

## Contribution

This study is the first to show that knee extensor strength normalized to body weight predicts patient-reported outcomes after open-wedge high tibial osteotomy.

## Key findings

- Knee extensor strength normalized to body weight was significantly correlated with IKDC subjective scores (r = 0.52, p < 0.001).
- KES/BW on the operated limb independently predicted better patient-reported outcomes at 12 months (β = 0.40, p = 0.02).

## Abstract

Knee extensor strength is a critical factor in patients with knee osteoarthritis. However, no studies have investigated whether knee extensor strength directly affects patient‐reported outcomes after open‐wedge high tibial osteotomy (OWHTO). The purpose of this study was to investigate the association between knee extensor strength and patient‐reported outcomes after OWHTO.

Patients who underwent OWHTO between 2016 and 2023 with knee function test results 12 months after surgery were included in this study. Isokinetic knee extensor strength was measured on the involved and uninvolved limb and normalised to body weight (KES/BW). Patient‐reported outcomes were assessed using the International Knee Documentation Committee (IKDC) subjective scores. Pearson correlation analysis and multivariable linear regression analysis were used to determine whether KES/BW on the involved limb was related to the IKDC subjective score.

Fifty‐eight knees from 52 patients who received OWHTO were evaluated. Pearson correlation analysis showed that KES/BW on the involved limb was significantly associated with the IKDC subjective score in OWHTO (r = 0.52, p < 0.001). Multivariable linear regression analysis indicated that KES/BW on the involved limb was independently associated with the IKDC subjective score at 12 months after OWHTO (β = 0.40, p = 0.02).

KES/BW on the involved limb was independently associated with the IKDC subjective score at 12 months after OWHTO. This metric should be considered to achieve better patient‐reported outcomes after OWHTO.

Level IV.