Background:Intra-articular platelet-rich plasma (PRP) injections have been proposed for the treatment of knee osteoarthritis (OA); however, their effectiveness in Japanese patients remains unclear.Purpose:To investigate whether 3 intra-articular injections of leukocyte-poor PRP (LP-PRP) improve symptoms and joint function in symptomatic Japanese patients with mild to moderate knee OA.Study Design:Randomized controlled trial; Level of evidence, 1.Methods:Of 72 patients screened, 30 were included and randomized to receive LP-PRP (n = 15) or saline (placebo; n = 15) injections between March 2019 and February 2023. Patients attended a screening visit and 3 treatment visits at 1 week apart, followed by 3 follow-up visits (at 4, 12, and 24 weeks) after the initial treatment visit. The primary efficacy outcome measure was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, whereas the secondary efficacy outcome measures were the proportion of patients showing a visual analog scale (VAS) improvement of ≥50%. Magnetic resonance imaging was performed to evaluate joint effusion and bone marrow lesions using the Whole-Organ Magnetic Resonance Imaging Score. Patients were followed for 24 weeks.Results:Patients in the PRP group (mean age, 65.9 years) had a mean hip-knee-ankle angle of 5.1°, with 7 and 8 patients demonstrating Kellgren-Lawrence grade 2 and 3 knee OA, respectively. Patients in the placebo group (mean age, 67.9 years) had a mean hip-knee-ankle angle of 3.8°, with 6 and 9 patients showing Kellgren-Lawrence grade 2 and 3 knee OA, respectively. No significant differences were identified in any baseline factors. The percentage change in Western Ontario and McMaster Universities Osteoarthritis Index scores from baseline to 24 weeks was significantly different (P= .032) between the PRP (median, 75.9%; quantile 1 [Q1], 49.6; quantile 3 [Q3], 94.1]) and placebo (median, 27.7%; Q1, –9.4; Q3, 80.9]) groups. Overall, 73.3% and 28.6% of the PRP group and placebo group, respectively, exhibited an improvement in visual analog scale scores of ≥50%, with a significant improvement observed in the PRP group ( P = .027). Changes in bone marrow lesions from baseline to 24 weeks, as assessed on magnetic resonance imaging, significantly differed between groups ( P = .017), with no significant differences in other secondary endpoints.Conclusion:In Japanese patients with knee OA, 3 intra-articular LP-PRP injections led to clinical improvements at 24-week follow-up and significant functional improvements and pain relief after 24 weeks.

中文翻译：

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注射贫白细胞富血小板血浆治疗日本人群中伴有关节积液或骨髓病变的症状性轻至中度膝骨关节炎的有效性：一项随机、双盲、安慰剂对照临床试验


背景：关节内注射富血小板血浆（PRP）已被提议用于治疗膝骨关节炎（OA）；然而，它们在日本患者中的有效性仍不清楚。目的：调查 3 次关节内注射白细胞贫乏 PRP (LP-PRP) 是否可以改善有症状的日本轻度至中度膝关节 OA 患者的症状和关节功能。研究设计：随机对照试验；证据级别，1.方法：在 72 名筛选的患者中，纳入了 30 名患者，并在 2019 年 3 月至 2023 年 2 月期间随机接受 LP-PRP（n = 15）或盐水（安慰剂；n = 15）注射。患者参加了筛选访视间隔 1 周进行 3 次治疗就诊，初次治疗就诊后进行 3 次随访（分别在 4、12 和 24 周）。主要疗效结果指标是西安大略大学和麦克马斯特大学骨关节炎指数 (WOMAC) 评分，而次要疗效结果指标是视觉模拟量表 (VAS) 改善≥50% 的患者比例。使用全器官磁共振成像评分进行磁共振成像以评估关节积液和骨髓病变。对患者进行了 24 周的随访。结果：PRP 组患者（平均年龄 65.9 岁）的平均髋膝踝角为 5.1°，其中 7 名和 8 名患者表现出 Kellgren-Lawrence 2 级和 3 级膝关节 OA，分别。安慰剂组患者（平均年龄 67.9 岁）的平均髋-膝-踝角为 3.8°，分别有 6 名和 9 名患者表现出 Kellgren-Lawrence 2 级和 3 级膝 OA。任何基线因素均未发现显着差异。 西安大略大学和麦克马斯特大学骨关节炎指数评分从基线到 24 周的百分比变化在 PRP 之间存在显着差异 (P= .032)（中位数，75.9%；分位数 1 [Q1]，49.6；分位数 3 [Q3]，94.1） ]）和安慰剂组（中位数，27.7%；Q1，–9.4；Q3，80.9]）组。总体而言，PRP 组和安慰剂组分别有 73.3% 和 28.6% 的人视觉模拟量表得分提高了 ≥50%，其中 PRP 组有显着改善 (P = .027)。根据磁共振成像评估，骨髓病变从基线到 24 周的变化在各组之间存在显着差异 (P = 0.017)，而其他次要终点没有显着差异。结论：在患有膝关节 OA 的日本患者中，3 名体内关节 LP-PRP 注射导致 24 周随访时临床改善，24 周后显着功能改善和疼痛缓解。