ISAKOS Congress 2021

2021 ISAKOS Biennial Congress ePoster

 

Evaluation Of Cartilage Repair After Open-Wedge High Tibial Osteotomy Using T2 Mapping Methods

Ken Iida, MD, Osaka JAPAN
Yusuke Hashimoto, MD, PhD, Sennan-Gun, Osaka JAPAN
Yohei Nishida, MD, Osaka JAPAN
Shinya Yamasaki, MD, PhD, Osaka JAPAN
Hiroaki Nakamura, MD, PhD JAPAN
Dept of Orthopedic Surgery Osaka City University Graduate School of Medicine, Osaka, JAPAN

FDA Status Not Applicable

Summary

This study demonstrated cartilage repair is induced opening-wedge HTO according to the ICRS grade, MOCART score in terms of structure, however there were no significant differences in T2 relaxation times in terms of qualitative improvements.

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Abstract

Introduction

Medial opening wedge high tibial osteotomy (OW-HTO) is established procedure to correct lower limb alignment and to reduce mechanical force on the medial compartment. As a result, biological remodeling including repair of articular cartilage is induced after HTO. Although repair of articular cartilage is sometimes confirmed as coverage with fibrocartilage arthroscopically, there are few articles that examined the degree of repaired cartilage in detail with Magnetic resonance imaging (MRI).
The purpose of this study was to evaluate the cartilage repair after HTO by arthroscopy, magnetic resonance observation of cartilage repair tissue (MOCART) score and MRI T2 mapping.

Methods

In 2013-2016, seven knees of 6 patients (mean age 58.7±6.4years) who were performed OW-HTO with microfracturewere enrolled this study. Arthroscopy was performed at the time of HTO, and at the time of plate removal (14.4±7.8 months after HTO). Status of articular cartilage was assessed according to the International Cartilage Repair Society (ICRS) grade. MRI examination was performed at 3, 6, and12 months postoperatively. MRI assessments were performed in using of the MOCART score and T2 relaxation times in T2 mapping (TR = 2100 ms, TE = 10, 20, 30, 40, 50, 60 ms, field of view = 16 cm, slice thickness = 3 mm, matrix = 352 × 352) at 3, 6, and 12 months postoperatively. Regions of interest (ROIs) were defined in one sagittal planes: medial femoral condyle (MFC) and medial tibial plateau (MTP).Comparisons of articular cartilage between preoperative ICRS grade and postoperative one were investigated using Pearson Chi square tests. Postoperative MOCART score and T2 relaxation times were investigated compared with each preoperative value using Student’s t test. An adjusted P value <0.05 was considered significant.

Results

The number of subjects in ICRS grade 1/2/3/4 was significantly improved from 0/0/3/4 preoperatively to 0/2/5/0 postoperatively in the MFC (P < 0.05) and 0/0/0/7 preoperatively to 0/0/6/1 postoperatively in the MTP (P < 0.05)(Table1). Mean MOCART score of the MFC at 3, 6, and12 months after surgery were 42.9, 51.4, 63.9 respectively, and mean MOCART score of the MTP were 49.3, 55.0 and 70.0 respectively. Mean MOCART score of the MFC and MTP 12 months after surgery showed a significant increase compared with the results 3 months after surgery (P < 0.05)(Fig1). Mean T2 values of the MFC at 3, 6, and12 months after surgery were 52.8ms, 51.3ms and 51.5ms respectively, and mean T2 relaxation times of the MTP were 49.2ms, 48.7ms and 48.2ms respectively, There were no differences in 3, 6, and12 months after surgery.(Fig2)

Conclusion

This study demonstrated cartilage repair is induced opening-wedge HTO according to the ICRS grade, MOCART score in terms of structure, however there were no significant differences in T2 relaxation times in terms of qualitative improvements.

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