2021 ISAKOS Biennial Congress ePoster
Reliability Of Preoperative Planning Method Considering Latent Medial Joint Laxity In Medial Open-Wedge High Tibial Osteotomy
Dong Jin Ryu, MD, PhD., Seoul KOREA, REPUBLIC OF
Kyeuback Kwon, MD, Osan-Si, Gyeonggi-do KOREA, REPUBLIC OF
Myung Ku Kim, MD, Inchon KOREA, REPUBLIC OF
Youngsik Jeon, MD, Seoul KOREA, REPUBLIC OF
Byoungyoul Kang, Daegu KOREA, REPUBLIC OF
Joon Ho Wang, MD, PhD, Seoul KOREA, REPUBLIC OF
SAMSUNG medical center, Seoul, Seoul, KOREA, REPUBLIC OF
FDA Status Cleared
Summary
An equation that is considering medial laxity could help to set a preoperative planning for optimal correction during MOWHTO.
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Abstract
Background
Soft tissue laxity around the knee joint has been recognized as a crucial factor affecting correction error during medial open-wedge high tibial osteotomy (MOWHTO). Particularly, the medial laxity, representing the changes in joint line convergence angle (JLCA), affects the soft tissue correction.
Hypothesis/Purpose: Quantify the medial laxity and develop a preoperative planning method that considers the medial laxity.
Methods
This study retrospectively reviewed 139 knees in 117 patients who underwent navigation-assisted MOWHTO from January 2014 to July 2019, for symptomatic medial compartment osteoarthritis with varus alignment >5°. We compared the results of two different preoperative planning methods used: 1) conventional Miniaci and 2) latent medial laxity reduction. We evaluated the incidence of under-correction, acceptable correction, and over-correction. The radiologic parameters were analyzed using the multiple linear regression with a stepwise selection model to establish an equation for the optimal preoperative planning method.
Results
The Miniaci method showed a higher incidence of over-correction (55.3%) than the latent medial laxity reduction method (22.8%) at postoperative 6 months (p=0.0006). The multiple linear regression with a stepwise selection model revealed a high correlation coefficient for the following equation: adjusted preoperative planning correction angle = 0.596 + 0.891 x target correction angle (TCA) - 0.255 x ?JLCA valgus (R2= 0.888). On simplifying, TCA – 1/3?JLCA valgus showed the highest intraclass coefficient (ICC) value (0.991) with the proposed equation. While, the Miniaci method showed a relatively low ICC value of 0.875.
Conclusion
The Conventional Miniaci method has a risk of over-correction after MOWHTO. An equation that is considering medial laxity could help to set a preoperative planning for optimal correction during MOWHTO.