Lateral tibial intercondylar eminence is a reliable reference for alignment correction in high tibial osteotomy

Abstract

Purpose: The purpose of the study is to determine whether the lateral tibial intercondylar eminence (LTIE) is a reliable reference for alignment correction in high tibial osteotomy (HTO).

Methods: A total of 1954 consecutive standing whole-leg radiography (WLR) examinations of 1373 adult patients with knee osteoarthritis between 2012 and 2019 were reviewed retrospectively; 145 patients were included, 53 males and 92 females, with a mean age of 63.3 years. Virtual simulation of HTO was performed to measure weight-bearing line (WBL) percentages and hip-knee-ankle (HKA) angles when the WBL passed through the Fujisawa, top, bottom, upper 1/3, and middle points of the lateral slope of the LTIE, and the positional relationship between the Fujisawa point and the lateral slope of the LTIE was determined.

Results: When the WBL passed through the top, bottom, upper 1/3, and middle points of the lateral slope of the LTIE, the mean WBL percentages were 57.7% ± 2.1%, 74.6% ± 3.3%, 63.4% ± 2.1%, and 66.2% ± 2.3%, respectively, and the mean HKA angles were 182.1° ± 0.5°, 185.9° ± 0.8°, 183.3° ± 0.5°, and 184.0° ± 0.5°, respectively. When the WBL passed through the Fujisawa point, it was passing through 28.6% ± 12.7% of the width of the lateral slope (the top and bottom points were defined as 0% and 100%, respectively). When the WBL passed through the middle and upper 1/3 points of the lateral slope of the LTIE, the majority of cases (96.1%-100%) were within the limits of acceptability, as defined by the widely accepted standard of a postoperative HKA angle ranging from 183° to 186°.

Conclusion: The upper 1/3 and middle points of the lateral slope of the LTIE are reliable references for guiding the alignment correction in HTO. In clinical application, if 62%-66% of the postoperative WBL percentage is the acceptable target range, the upper 1/3 point of the lateral slope of the LTIE may be a better alternative than the midpoint. If the postoperative HKA angle between 183° and 186° is acceptable, the midpoint of the lateral slope of the LTIE may be better than the upper 1/3 point. These findings are crucial for the accuracy of the traditional intraoperative alignment assessment techniques.

Level of evidence: IV.

Keywords: High tibial osteotomy; Lateral tibial intercondylar eminence; Osteoarthritis; Virtual simulation; Whole-leg radiographs.