Okada Sayaka, Taniguchi Masashi, Yagi Masahide, Okada Shogo, Nakazato Kaede, Motomura Yoshiki, Fukumoto Yoshihiro, Kobayashi Masashi, Kanemitsu Kyoseki, Ichihashi Noriaki
Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Faculty of Rehabilitation, Kansai Medical University, Osaka, Japan.
Clin Rheumatol. 2025 Apr 30. doi: 10.1007/s10067-025-07442-8.
To clarify the association between infrapatellar fat pad (IFP) stiffness and size with knee osteoarthritis (OA) severity and knee symptoms.
This study included 93 participants: 66 with symptomatic medial knee OA (Kellgren-Lawrence grade [KL] ≥ 2) and 27 healthy controls (KL grade 0 or 1) with asymptomatic knees. Shear modulus (stiffness) and thickness (size) of the IFP were measured using ultrasonography. The Knee Society Score (KSS) was used to assess knee symptoms. Maximum knee extension strength and external knee adduction moment during walking, both related to the symptoms of knee OA, were measured. The shear modulus and thickness of the IFP were compared among three groups: control, mild OA (KL grade 2), and severe OA (KL grades 3 and 4). Multiple regression analysis was performed to determine the association of IFP shear modulus and thickness with knee symptoms.
The IFP shear modulus was higher in the severe OA group than that in the control group, with no significant differences among the other groups. There were no significant differences in thickness between the groups. The shear modulus was significantly associated with the KSS symptom scores, indicating that a stiffer IFP correlated with more severe knee OA symptoms. Conversely, the IFP thickness was not associated with the KSS symptom scores.
Infrapatellar fat pad stiffness was higher in severe knee OA, and greater stiffness was associated with more severe symptoms, suggesting that IFP stiffness may serve as both an assessment marker and therapeutic target in knee OA management.
阐明髌下脂肪垫（IFP）的硬度和大小与膝关节骨关节炎（OA）严重程度及膝关节症状之间的关联。
本研究纳入了93名参与者：66例有症状的膝关节内侧OA患者（Kellgren-Lawrence分级[KL]≥2级）和27名健康对照者（KL分级为0或1级），其膝关节无症状。使用超声测量IFP的剪切模量（硬度）和厚度（大小）。采用膝关节协会评分（KSS）评估膝关节症状。测量了与膝关节OA症状相关的最大膝关节伸展力量和行走时的膝关节外展力矩。比较了三组人群（对照组、轻度OA组[KL 2级]和重度OA组[KL 3级和4级]）的IFP剪切模量和厚度。进行多元回归分析以确定IFP剪切模量和厚度与膝关节症状之间的关联。
重度OA组的IFP剪切模量高于对照组，其他组之间无显著差异。各组之间的厚度无显著差异。剪切模量与KSS症状评分显著相关，表明IFP越硬，膝关节OA症状越严重。相反，IFP厚度与KSS症状评分无关。
重度膝关节OA患者的髌下脂肪垫硬度较高，且硬度越大，症状越严重，这表明IFP硬度可作为膝关节OA管理中的评估指标和治疗靶点。
