This study revealed the change in the paravertebral muscles in patients with osteoporotic vertebral fracture. Increased pain is likely to be the driver for reduced activity, reduced activities of daily living, and consequent increase in fat infiltration of the paravertebral muscles, assumed to be secondary to reduced activity level or, conversely, partial immobilization. INTRODUCTION To reveal the time courses and impact of the paravertebral muscles (PVMs) on the healing process of osteoporotic vertebral fractures and risk factors for PVM decrease. METHODS Consecutive patients with symptomatic osteoporotic vertebral fractures were enrolled in 11 hospitals. At enrollment and 3- and 6-month follow-up, PVMs, including the multifidus and erector spinae, were examined using magnetic resonance imaging (MRI). The PVM cross-sectional area (CSA) and fat signal fraction (FSF) were measured at L3. Low back pain (LBP), activities of daily living (ADLs), and risk factors for PVM decrease at the 6-month follow-up were investigated. PVM decrease was defined as > 1 standard deviation decrease of the CSA or > 1 standard deviation increase of the FSF. RESULTS Among 153 patients who completed the 6-month follow-up, 117 (92 women, 79%) had MRI of L3 at enrollment and 3- and 6-month follow-up (mean age at enrollment, 78.5 years). The CSA did not change 6 months from onset (p for trend = 0.634), whereas the FSF significantly increased (p for trend = 0.033). PVM decrease was observed in 30 patients (26%). LBP was more severe, and delayed union was more frequent in patients with PVM decrease (p = 0.021 mixed-effect model and p = 0.029 chi-square test, respectively). The risk factors for PVM decrease were ADL decline at the 3-month follow-up (adjusted odds ratio = 5.35, p = 0.026). CONCLUSION PVM decrease was significantly related to LBP and delayed union after osteoporotic vertebral fracture onset. ADL decline at the 3-month follow-up was a risk factor for PVM decrease. Therefore, restoring ADLs within 3 months after onset is important.

中文翻译：

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骨质疏松性椎体骨折发作后椎旁肌的自然进程。

这项研究揭示了骨质疏松性椎体骨折患者椎旁肌肉的变化。疼痛加剧可能是导致活动减少，日常生活活动减少以及由此导致的椎旁肌脂肪浸润增加的驱动力，这被认为是活动水平降低或相反的部分固定。引言为了揭示椎旁肌肉（PVM）的时程和对骨质疏松性椎骨骨折愈合过程的影响以及PVM降低的危险因素。方法连续性有症状的骨质疏松性椎体骨折的患者入选11家医院。在入组以及3个月和6个月的随访中，使用磁共振成像（MRI）检查了PVM，包括多缝和竖脊肌。在L3处测量PVM横截面积（CSA）和脂肪信号分数（FSF）。在6个月的随访中，研究了下腰痛（LBP），日常生活活动（ADL）和PVM降低的危险因素。PVM降低定义为CSA> 1标准偏差降低或FSF> 1标准偏差增加。结果在完成6个月随访的153例患者中，有117例（92名女性，占79％）在入组时进行了L3 MRI检查，并在3个月和6个月进行了随访（入组平均年龄为78.5岁）。发病6个月后CSA不变（趋势p = 0.634），而FSF明显增加（趋势p = 0.033）。在30例患者中观察到PVM下降（26％）。PVM降低的患者的LBP更为严重，延迟延迟愈合更为频繁（p = 0.021混合效应模型和p = 0.029卡方检验，分别）。PVM下降的危险因素是在3个月的随访中ADL下降（校正后的优势比= 5.35，p = 0.026）。结论骨质疏松性椎体骨折发作后PVM降低与LBP和延迟愈合密切相关。3个月随访中ADL下降是PVM下降的危险因素。因此，在发病后3个月内恢复ADL很重要。