Department of Physical Therapy, University of Nevada, Las Vegas.
J Geriatr Phys Ther. 2019 Jul/Sep;42(3):E35-E41. doi: 10.1519/JPT.0000000000000185.
Although discomfort during walking is a common complaint in individuals with knee osteoarthritis (OA), how an acute bout of walking affects femoral cartilage remains unclear. Current literature has suggested that frontal plane knee malalignment (ie, varus and valgus) is associated with the initiation and/or progression of knee OA. However, the association between knee alignment and femoral cartilage deformation after an acute bout of loading has not yet been investigated. This study was aimed to compare the acute effects of walking on femoral cartilage deformation between older adults with and without knee OA. We also examined the association between frontal plane knee alignment and loading-induced femoral cartilage deformation.
Ten persons without OA (Kellgren Lawrence grading = 0 or 1; 5 females and 5 males; 55.0 [1.8] years of age; 78.8 [14.1] kg; 1.8 [0.2] m) and 9 persons with OA (Kellgren Lawrence grading ≥2; 4 females and 5 males; 55.6 [4.5] years of age; 97.4 [15.0] kg; 1.7 [0.1] m) participated. Each participant underwent magnetic resonance imaging before and immediately after 30 minutes of fast walking at 3 to 4 miles per hour. To obtain cartilage deformation postwalking, the medial and lateral femoral cartilage of the weight-bearing areas was segmented on participants' magnetic resonance imaging. Cartilage thickness was quantified by computing the average perpendicular distance between opposing voxels defining the edges of the femoral cartilage. Cartilage deformation of the medial and lateral femurs was defined as the percent changes in cartilage thickness after walking. Frontal plane knee alignment was obtained by measuring the angle between the long axes of femur and tibia. Independent t tests were used to compare cartilage deformation between the 2 groups. Pearson correlation coefficients were used to assess the association between cartilage deformation and knee alignment.
There was no significant difference in cartilage deformation between the OA and control groups in lateral (P = .69) or medial (P = .87) femur. A significant correlation was found between lateral femoral cartilage deformation and increased knee valgus alignment (r = 0.497; P = .03). No difference was found between medial femoral cartilage deformation and frontal plane knee alignment (r = 273; P = .26).
This is the first study comparing the acute effects of walking on femoral cartilage deformation between older adults with and without knee OA. Although there was not a difference in walking-induced femoral cartilage deformation between the OA and control groups, knee valgus was related to lateral femoral cartilage deformation after walking. Our findings suggested that walking exercises may be used safely in older adults without knee malalignment.
尽管膝关节骨关节炎（OA）患者在行走时感到不适是一种常见症状，但急性行走对股骨软骨的影响仍不清楚。目前的文献表明，膝关节在额状面上的对线不良（即内翻和外翻）与膝 OA 的发生和/或进展有关。然而，在急性负荷后，膝关节对线与股骨软骨变形之间的关系尚未得到研究。本研究旨在比较膝 OA 患者与非 OA 患者在行走时股骨软骨变形的急性影响。我们还检查了额状面膝关节对线与负荷诱导的股骨软骨变形之间的关系。
10 名无 OA 者（Kellgren Lawrence 分级=0 或 1；5 名女性和 5 名男性；55.0[1.8]岁；78.8[14.1]kg；1.8[0.2]m）和 9 名有 OA 者（Kellgren Lawrence 分级≥2；4 名女性和 5 名男性；55.6[4.5]岁；97.4[15.0]kg；1.7[0.1]m）参与了本研究。每位参与者在以 3 至 4 英里/小时的速度快走 30 分钟前后都接受了磁共振成像检查。为了获得行走后的软骨变形，我们在参与者的磁共振图像上对负重区的股骨内外侧软骨进行了分割。通过计算定义股骨软骨边缘的相对立体素之间的垂直距离来量化软骨厚度。股骨内外侧的软骨变形定义为行走后软骨厚度的百分比变化。额状面膝关节对线通过测量股骨和胫骨长轴之间的角度获得。采用独立 t 检验比较两组间的软骨变形。采用 Pearson 相关系数评估软骨变形与膝关节对线的关系。
OA 组和对照组在外侧（P=0.69）或内侧（P=0.87）股骨的软骨变形无显著差异。外侧股骨软骨变形与膝关节外翻角度增加呈显著相关（r=0.497；P=0.03）。内侧股骨软骨变形与额状面膝关节对线无差异（r=0.273；P=0.26）。
这是第一项比较膝 OA 患者与非 OA 患者行走时股骨软骨变形急性影响的研究。虽然 OA 组和对照组在行走引起的股骨软骨变形方面没有差异，但膝外翻与行走后外侧股骨软骨变形有关。我们的研究结果表明，在没有膝关节对线不良的老年人中，可以安全地进行步行运动。
