2023 ISAKOS Biennial Congress ePoster
Assessing The Relationship Between Knee Joint Biomechanics and Trunk Posture According To Osteoarthritis Severity
Yuki Suzuki, MD, PhD, Sapporo JAPAN
Yasumitsu Ohkoshi, MD, Hakodate, Hokkaido JAPAN
Kensaku Kawakami, Ph.D., Hakodate, Hokkaido JAPAN
Kenta Shimizu, P.T., Hakodate, Hokkaido JAPAN
Shuya Chida, P.T., Hakodate, Hokkaido JAPAN
Kengo Ukishiro, PT, MS, Hakodate, Hokkaido JAPAN
Tomohiro Onodera, MD, PhD, Sapporo, Hokkaido JAPAN
Koji Iwasaki, MD, PhD, Sapporo, Hokkaido JAPAN
Tatsunori Maeda, MD, Hakodate, Hokkaido JAPAN
Shoji Suzuki, M.eng, Hakodate, Hokkaido JAPAN
Eiji Kondo, MD, PhD, Sapporo, Hokkaido JAPAN
Norimasa Iwasaki, MD, PhD, Sapporo, Hokkaido JAPAN
Hakodate Orthopedic Clinic, Hakodate, Hokkaido, JAPAN
FDA Status Not Applicable
Summary
We have clarified the kinematics and kinetics of medial knee osteoarthritis (OA) according to its severity, and their relationship with trunk flexion.
ePosters will be available shortly before Congress
Abstract
Introduction
Exacerbation of medial knee osteoarthritis (OA) leads to decreased activity and reduction in healthy life expectancy. Biomechanical factors are important in progression of OA. The external knee joint moment is strongly influenced by the position of the body weight center, thus it is important to analyze the trunk posture. To understand the alteration in trunk posture during walking, parameters of the knee joint not only in the coronal plane but in the sagittal plane are important. However, they have not been fully elucidated yet. The purpose of this study is to clarify the kinematics and kinetics of OA according to its severity, and their relationship with trunk posture.
Methods
Between November 2014 and October 2018, 75 OA patients (95 knees) who underwent gait analysis were enrolled in this study. Kellgren-Lawrence classification was used for radiographic evaluation. There were 20 patients with 24 knees (mean age 59.2 years) in grade 2, 25 patients with 28 knees (mean age 62.6 years) in grade 3, and 30 patients with 43 knees (mean age 68.1 years) in grade 4. Hip-knee-ankle angle (HKA) and percentage of mechanical axis (%MA) were measured radiographically. All patients were assessed while walking at a self-selected speed using an optical motion capture system; subsequently, gait speed, knee range of motion were assessed, and six degrees of freedom knee joint kinematics and trunk flexion angle were calculated using the Point Cluster Technique. Three moment components at the knee joint were calculated by using inverse dynamics. Moreover, TJM (TJM=v(KAM2+KFM2+KRM2)) and relative contributions of each moment components at the knee (e.g. %KAM=KAM2/TJM2 *100) at maximum reaction force data were evaluated. Statistical analysis was performed using Bonferroni test.
Results
The gait speed and knee range of flexion decreased decreased (P < 0.05), and HKA and %MA were high and low respectively (P < 0.01) according to OA severity. The relative contribution of each moment at the 1st peak of TJM was KFM dominant in mild OA and KAM dominant in severe OA. In cases of grade 4, the %KAM was significantly higher, but %KFM was lower (P < 0.05) (Figure 1). The trunk flexion was observed in grade 4 compared to grades 2 and 3 throughout whole gait (P < 0.01).
Discussion And Conclusion
High %KAM in severe OA cases was thought to be the result of increase in moment lever arm due to severe varus deformity. Low %KFM was thought to be not only the result of aging-related but also compensatory trunk flexion due to pain and decrease of quadriceps activity. Additionally, referring to OA progression, sagittal factors such as KFM and trunk posture interact with each other, which may result in a vicious cycle Thus, not only changes in coronal factors but also in sagittal factors are related with severity of OA. In order to consider early conservative or surgical intervention for OA, a comprehensive assessment of knee, hip and trunk posture should be considered from a biomechanical perspective.