Background:

Previous studies have shown that runners demonstrate elevated T2 and T1ρ values on magnetic resonance imaging (MRI) after running a marathon, with the greatest changes in the patellofemoral and medial compartment, which can persist after 3 months of reduced activity. Additionally, marathon running has been shown to increase serum inflammatory markers. Hyaluronic acid (HA) purportedly improves viscoelasticity of synovial fluid, serving as a lubricant while also having chondroprotective and anti-inflammatory effects.

Purpose/Hypothesis:

The purpose was to investigate whether intra-articular HA injection can protect articular cartilage from injury attributed to marathon running. The hypothesis was that the addition of intra-articular HA 1 week before running a marathon would reduce the magnitude of early cartilage breakdown measured by MRI.

Study Design:

Randomized controlled trial; Level of evidence, 2.

Methods:

After institutional review board approval, 20 runners were randomized into receiving an intra-articular injection of HA or normal saline (NS) 1 week before running a marathon. Exclusionary criteria included any prior knee injury or surgery and having run >3 prior marathons. Baseline 3-T knee MRI was obtained within 48 hours before the marathon (approximately 5 days after injection). Follow-up 3-T MRI scans of the same knee were obtained 48 to 72 hours and 3 months after the marathon. The T2 and T1ρ relaxation times of articular cartilage were measured in 8 locations—the medial and lateral compartments (including 2 areas of each femoral condyle) and the patellofemoral joint. The statistical analysis compared changes in T2 and T1ρ relaxation times (ms) from baseline to immediate and 3-month postmarathon scans between the HA and NS groups with repeated measures analysis of variance.

Results:

Fifteen runners completed the study: 6 women and 2 men in the HA group (mean age, 31 years; range, 23-50 years) and 6 women and 1 man in the NS group (mean age, 27 years; range, 20-49 years). There were no gross morphologic MRI changes after running the marathon. Postmarathon studies revealed no statistically significant changes between the HA and NS groups in all articular cartilage areas of the knee on both T2 and T1ρ relaxation times.

Conclusion:

Increased T2 and T1ρ relaxation times have been observed in marathon runners, suggesting early cartilage injury. The addition of intra-articular HA did not significantly affect relaxation times in all areas of the knee when compared with an NS control.

中文翻译：

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注射透明质酸能否预防马拉松赛跑后出现的早期软骨损伤？利用高场磁共振成像的随机对照试验。

背景：

先前的研究表明，跑步者在进行马拉松比赛后通过磁共振成像（MRI）表现出T2和T1ρ值升高，and股和内侧腔的变化最大，这种变化在运动量减少3个月后仍会持续。此外，马拉松赛跑已显示会增加血清炎症标志物。透明质酸（HA）据称可改善滑液的粘弹性，既可起到润滑剂的作用，又具有软骨保护和抗炎作用。

目的/假设：

目的是研究关节内注射HA是否可以保护关节软骨免受马拉松赛跑所致的伤害。假设是在进行马拉松比赛前1周添加关节内HA将减少MRI测得的早期软骨衰竭的程度。

学习规划：

随机对照试验; 证据水平2。

方法：

经机构审查委员会批准后，在进行马拉松比赛前1周，将20名跑步者随机分配接受关节内注射HA或生理盐水（NS）。排除标准包括任何先前的膝盖受伤或手术，并且进行过3次以上的马拉松比赛。在马拉松比赛前48小时内（注射后约5天）获得基线3-T膝部MRI。马拉松比赛后48到72小时和3个月，对同一膝盖进行了3-T MRI随访。在8个位置（内侧和外侧隔室（每个股骨dy的2个区域）和the股关节）测量了关节软骨的T2和T1ρ松弛时间。

结果：

15名跑步者完成了研究：HA组中的6名女性和2名男性（平均年龄为23至50岁）和NS组中的6名女性和1名男性（平均年龄为27岁；范围为20- 49年）。马拉松比赛后，MRI的总体形态没有改变。马拉松后研究表明，在T2和T1ρ放松时间，膝关节所有软骨区域的HA组和NS组之间没有统计学上的显着变化。

结论：

在马拉松运动员中观察到增加的T2和T1ρ弛豫时间，这表明了早期的软骨损伤。与NS对照相比，关节内HA的添加并未显着影响膝盖所有区域的放松时间。