The Prevalence of Hallux Rigidus and its Risk Factors

Abstract

Category: Midfoot/Forefoot Introduction/Purpose: Hallux rigidus (HR) is known as osteoarthritis of the first metatarsophalangeal joint (MPJ). The radiographical findings of HR are characterized by joint space narrowing, osteophytic lipping of the metatarsal head and proximal phalanx and sesamoid hypertrophy. HR is not so rare in daily medical practice, but its prevalence and risk factors are not completely understood. The purpose of this cross-sectional study, using a population-sample from Japan, is to investigate the prevalence of HR and its risk factors among Japanese community dwellers. Methods: In this study, we analyzed the cohort studies in 2009, 2011, 2013 and 2015 covering the elderly (=50 years). We excluded the participants with hallux valgus (HV) because it is difficult to distinguish HR from HV completely. Knee osteoarthritis (KOA) was scored according to the Kellgren-Lawrence grading system and was defined as grade=2. HR was scored according to the Hattrup and Johnson classification and was defined as grade=1. Continuous and categorical variables were compared using the t-test and chi-square test, respectively. The logistic regression model was used to examine the relationship between predictor variables and HR. The Cochran-Armitage trend test was used to examine the relationships between the presence or absence of HR and the severity of KOA in a linear trend. All p values presented are two-sided and p values < 0.05 were considered statistically significant. Results: A total of 416 (171 men, 245 women) participants fulfilled this study criterion. The prevalence of HR was 17.8%. The rate of grade0, grade1, grade2, and grade3 of HR were 82.2%, 10.1%, 6.7%, and 0.96%, respectively. Univariate analysis revealed age (=65), KOA, and Gout Attack (GA) were significantly associated with HR (Table 1). In addition, they were confirmed as independent risk factors of HR in the multivariate analysis. All parameters were significantly associated with HR. The odds ratio of age, KOA, and GA were 2.46, 1.83, and 4.87, respectively (p <0.05). KOA severity is significantly associated with the presence or absence of HR (p <0.05). Conclusion: While previous reports have demonstrated a higher prevalence of HR (27.2-44.4%), HV was not excluded in that study. To achieve the accurate evaluation, we examined the epidemiology and prevalence of HR among participants without HV. HR prevalence in the elderly (=50 years) was 17.8%. Although multifactorial risk factors have been proposed in the literature, our study revealed that age (=65), KOA, and GA were the independent risk factors for HR. KOA severity was associated with the presence or absence of HR.