Relationship between fibular head height and varus knee osteoarthritis occurrence and severity / 中华骨科杂志

ABSTRACT

Objective:To explore the correlation between fibular head height and varus knee osteoarthritis occurrence and severity.Methods:A retrospective analysis was performed on 618 participants (618 knees, 184 males and 434 females, mean age 61.12±10.98 years) who underwent standard weight-bearing full-leg radiographs and were diagnosed as non-knee osteoarthritis or varus knee osteoarthritis from January 2019 to June 2019. Knee osteoarthritis was diagnosed according to Kellgren-Lawrence grading 0-I grades were diagnosed as non-osteoarthritis, II-IV grades were diagnosed as osteoarthritis. Joint line convergence angle (JLCA), medial proximal tibial angle (MPTA) and hip-knee-ankle angle were measured on X-rays to reflect varus deformity. The fibular head height was defined as the vertical distance from upper edge of fibular head to lateral tibial plateau. Patients were divided into 5 groups according to Kellgren-Lawrence grading. Differences of age, gender, height, weight, body mass index, varus deformity (JLCA, MPTA and hip-knee-ankle angle) between Kellgren-Lawrence 0-IV grades were compared. Ordinal logistic regression was performed to analyze the correlation between fibular head height and Kellgren-Lawrence grades. Pearson's correlation analysis was used for the correlation among fibular head height, JLCA, MPTA and hip-knee-ankle angle, and the main factor of JLCA, MPTA and hip-knee-ankle angle was extracted by factor analysis. Multiple linear regressions were used to analyze the correlation between fibular head height and varus deformity score.Results:There were 68, 66, 97, 98, 289 participants in Kellgren-Lawrence grades 0-IV respectively that was 134 participants were diagnosed as non-osteoarthritis and 484 participants were diagnosed as osteoarthritis. Fibular head height and MPTA showed a decreasing trend ( F=129.076, 24.875; P<0.001) while JLCA and hip-knee-ankle angle showed an increasing trend ( F=414.346, 105.996; P<0.001) with the increase in Kellgren-Lawrence grading. Age, body mass index and fibular head height are influencing factors of Kellgren-Lawrence grading with OR(95%CI) were 1.116(1.093, 1.141), 1.363(1.060, 1.754), 0.617(0.575, 0.662) . Fibular head height was negatively correlated with JLCA and hip-knee-ankle angle ( r=-0.641, -0.478; P<0.001) , respectively, and positively correlated with MPTA ( r=0.320, P<0.001). There were significant correlations between age, fibular head height and the varus deformity score ( β=0.274, -0.457; P<0.001). Conclusion:Fibular head height of patients with varus knee osteoarthritis is lower than that of non-osteoarthritis. In addition to age and body mass index, fibular head height is a risk factor for varus knee osteoarthritis occurrence. The smaller the fibular head height is, the more serious the osteoarthritis severity and varus deformity are.