Satake Yoshinori, Izumi Masashi, Aso Koji, Igarashi Yoichi, Sasaki Nao, Ikeuchi Masahiko
Department of Orthopaedic Surgery, Kochi Medical School, Kochi University, Kochi, Japan.
Department of Orthopaedic Surgery, Tosa Municipal Hospital, Kochi, Japan.
J Pain Res. 2021 Apr 20;14:1113-1118. doi: 10.2147/JPR.S298100. eCollection 2021.
Patients with knee osteoarthritis (OA) complain of various types of pain, divided into two main categories: pain on movement and pain at rest. A thorough understanding of pain is essential for managing knee OA; however, few studies have investigated the mechanisms underlying the two different types of pain. This study aimed to clarify the predisposing factors for pain in patients with knee OA with a focus on differences between pain on walking and pain at rest.
This study involved 93 patients, aged 44-90 years, with knee OA, including 74 women. We assessed demographic variables (sex, age, body mass index [BMI], side), visual analogue scale (VAS) score on walking, VAS score at rest, Kellgren and Lawrence (KL) grade on radiograph, synovitis score and bone marrow lesion (BML) score on magnetic resonance imaging, and pressure pain threshold (PPT), and used univariate and multiple regression analyses to investigate factors predisposing patients to pain at rest or pain on walking.
In the univariate analyses, we found significant correlations between VAS score on walking and BMI (r=0.31, p<0.01), KL grade (r=0.40, p<0.01), synovitis score (r=0.26, p=0.01), and BML score (r=0.36, p<0.01), whereas VAS score at rest correlated with PPT (r=-0.23, p=0.02) and BMI (r= 0.26, p=0.01). Multiple regression analysis showed that significant explanatory factors for VAS score on walking were BMI (β=0.22, p=0.03) and KL grade (β=0.27, p=0.03). By contrast, PPT was the only significant explanatory factor for VAS score at rest (β=-0.27, p=0.01).
Predisposing factors were significantly different between pain on walking and pain at rest, indicating that different pain mechanisms exist in the two types of pain. Pain on walking was more strongly associated with mechanical and structural factors, while pain at rest was associated with mechanical hyperalgesia of the knee.
University Hospital Medical Information Network Clinical Trials Registration number; 000041190.
膝关节骨关节炎（OA）患者会出现多种类型的疼痛，主要分为两大类：运动时疼痛和静息时疼痛。全面了解疼痛对于膝关节OA的治疗至关重要；然而，很少有研究探讨这两种不同类型疼痛背后的机制。本研究旨在明确膝关节OA患者疼痛的诱发因素，重点关注步行时疼痛和静息时疼痛的差异。
本研究纳入了93例年龄在44 - 90岁之间的膝关节OA患者，其中女性74例。我们评估了人口统计学变量（性别、年龄、体重指数[BMI]、患侧）、步行时视觉模拟评分（VAS）、静息时VAS评分、X线片上的凯尔格伦和劳伦斯（KL）分级、磁共振成像上的滑膜炎评分和骨髓水肿（BML）评分以及压痛阈值（PPT），并采用单因素和多因素回归分析来研究导致患者静息时疼痛或步行时疼痛的因素。
在单因素分析中，我们发现步行时VAS评分与BMI（r = 0.31，p < 0.01）、KL分级（r = 0.40，p < 0.01）、滑膜炎评分（r = 0.26，p = 0.01）和BML评分（r = 0.36，p < 0.01）之间存在显著相关性，而静息时VAS评分与PPT（r = -0.23，p = 0.02）和BMI（r = 0.26，p = 0.01）相关。多因素回归分析显示，步行时VAS评分的显著解释因素是BMI（β = 0.22，p = 0.03）和KL分级（β = 0.27，p = 0.03）。相比之下，PPT是静息时VAS评分的唯一显著解释因素（β = -0.27，p = 0.01）。
步行时疼痛和静息时疼痛的诱发因素存在显著差异，表明这两种类型的疼痛存在不同的疼痛机制。步行时疼痛与机械和结构因素的关联更强，而静息时疼痛与膝关节的机械性痛觉过敏有关。
大学医院医学信息网络临床试验注册号；000041190。
