Objective

Immediate cartilage structural alterations in the acute phase after an anterior cruciate ligament (ACL) rupture may be a precursor to posttraumatic osteoarthritis (PTOA) development. Our aim was to describe changes in cartilage matrix in the subacute phase of the acutely ACL-injured knee compared to the contralateral uninjured knee.

Design

Participants (n = 118) aged 15–40 years with an acute ACL injury were consecutively included in subacute phase after acute ACL-injury and underwent MRI (mean 29 days post trauma) of both knees. Mean T2 relaxation times, T2 spatial coefficient of variation and cartilage thickness were determined for different regions of the tibiofemoral cartilage. Differences between the acutely ACL-injured and uninjured knee were evaluated using Wilcoxon signed-rank test.

Results

T2 relaxation time in injured knees was increased in multiple cartilage regions from both medial and lateral compartment compared to contralateral knees, mostly in medial trochlea and posterior tibia (P-value<0.001). In the same sites of injured knees, we observed significantly thinner cartilage. Moreover, injured knees presented shorter T2 relaxation time in superficial cartilage on lateral central femur and trochlea (P-value<0.001), and decreased T2 spatial coefficient of variation in lateral trochlea and load bearing regions of medial-central femoral condyle and central tibia in both compartments.

Conclusion

Small but statistically significant differences were observed in the subacute phase between ACL-injured and uninjured knee in cartilage T2 relaxation time and cartilage thickness. Future longitudinal observations of the same cohort will allow for better understanding of early development of PTOA.

Trial registration number

NCT02931084.

中文翻译：

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通过 T2 映射对急性前交叉韧带损伤与对侧膝关节患者的胫股关节软骨进行定量评估：使用 NACOX 研究队列数据的亚急性期结果

客观的

前交叉韧带 (ACL) 断裂后急性期的即时软骨结构改变可能是创伤后骨关节炎 (PTOA) 发展的前兆。我们的目的是描述与对侧未受伤膝关节相比，急性 ACL 损伤膝关节亚急性期软骨基质的变化。

设计

患有急性 ACL 损伤的 15-40 岁的参与者 ( n  = 118) 在急性 ACL 损伤后连续进入亚急性期，并接受了双膝的 MRI（创伤后平均 29 天）。测定了胫股软骨不同区域的平均 T2 弛豫时间、T2 空间变异系数和软骨厚度。使用 Wilcoxon 符号秩检验评估急性 ACL 损伤和未损伤膝关节之间的差异。

结果

与对侧膝关节相比，损伤膝关节内侧和外侧的多个软骨区域的T2松弛时间增加，主要是内侧滑车和胫骨后部（P值<0.001）。在受伤膝盖的相同部位，我们观察到软骨明显变薄。此外，受伤的膝关节股骨中央外侧和滑车的浅表软骨T2松弛时间更短（P值<0.001），外侧滑车的T2空间变异系数以及股骨内侧中央髁和胫骨中央承载区的T2空间变异系数降低。两个隔间。

结论

在 ACL 损伤和未损伤膝关节的亚急性期，在软骨 T2 松弛时间和软骨厚度方面观察到了微小但具有统计学意义的差异。未来对同一队列的纵向观察将有助于更好地了解 PTOA 的早期发展。

试用注册号

NCT02931084。