2017 ISAKOS Biennial Congress ePoster #1519

 

How Could We Prevent Overcorrection in Medial Open-Wedge High Tibial Osteotomy?

Do-Kyung Lee, MD, Daejeon KOREA, REPUBLIC OF
Joon Ho Wang, MD, PhD, Seoul KOREA, REPUBLIC OF
Jun-Ho Kim, MD, Seoul KOREA, REPUBLIC OF
Kwang-Jun Oh, MD, PhD, Seoul KOREA, REPUBLIC OF
Dae Hee Lee, MD, PhD, Seoul KOREA, REPUBLIC OF

Department of Orthopaedic Surgery Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul, KOREA, REPUBLIC OF

FDA Status Not Applicable

Summary

The correction error was associated with the change of JLCA, and the change of JLCA angle was statistically larger in the over-correction group than in the acceptable group. Valgus capacity, correction angle, and age were confirmed to affect the change of JLCA angle.

ePosters will be available shortly before Congress

Abstract

Background

The large change of joint line convergence angle (JLCA) has been suggested to be associated with overcorrection in high tibial osteotomy (HTO). However, there have only been a few studies investigating the correlation between overcorrection and the change of JLCA and the factors that affect the change of JLCA.

Purpose

The purpose of this study was to investigate the relationship between overcorrection and the change of JLCA and the factors that affect the change of JLCA.

Study designs: Cohort study (diagnosis), Level of evidence, 2

Methods

A total of 34 patients underwent medial open wedge HTO with a navigation system. The change of the HKA angle was divided into two groups: acceptable and over-correction. The acceptable group was defined by having a correction error that was within 3°, while the over-correction group was defined by having a correction error of over 3°. The change of JLCA and the correction error were measured in each group with navigation information and pre- and post-operative radiographs.

Results

The correction error and the change of JLCA were -1.4±1.4° and -1.3±1.4° in the acceptable group and -4.4±1.1°and -4.3±1.1°, respectively, in the over-correction group. The change of JLCA was significantly larger in the over-correction group than in the acceptable group (p < 0.001). In the Pearson correlation analysis the coefficient of correlation between the correction error and the change of JLCA was 0.680 (p < 0.001). When analyzing which factors have an effect on the change of JLCA, Valgus capacity was statistically highly correlated with the change of JLCA (B = -0.522, p = 0.004) and the correction angle and age were statistically borderline correlated with the change of JLCA (B=0.161 and -0.052, p-value = 0.081 and 0.056).

Conclusion

The main cause of correction error is the change of JLCA, and it is affected by valgus capacity, correction angle, and age.

Clinical significance: Preoperative checking of valgus capacity could decide the appropriate correction angle by using the regression model. It could prevent over-correction in HTO.

Keywords: High tibial osteotomy, Soft tissue laxity, Joint line convergence angle (JLCA), Over-correction, Valgus capacity