Biercevicz Alison M, Akelman Matthew R, Fadale Paul D, Hulstyn Michael J, Shalvoy Robert M, Badger Gary J, Tung Glenn A, Oksendahl Heidi L, Fleming Braden C
Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, Rhode Island, USA.
Department of Medical Biostatistics, University of Vermont, Burlington, Vermont, USA.
Am J Sports Med. 2015 Mar;43(3):693-9. doi: 10.1177/0363546514561435. Epub 2014 Dec 24.
Clinical, functional, and patient-oriented outcomes are commonly used to evaluate the efficacy of treatments after anterior cruciate ligament (ACL) injury; however, these evaluation techniques do not directly measure the biomechanical changes that occur with healing.
To determine if the magnetic resonance (MR) image-derived parameters of graft volume and signal intensity (SI), which have been used to predict the biomechanical (ie, structural) properties of the graft in animal models, correlate with commonly used clinical (anteroposterior [AP] knee laxity), functional (1-legged hop), and patient-oriented outcome measures (Knee Injury and Osteoarthritis Outcome Score [KOOS]) in patients 3 and 5 years after ACL reconstruction.
Cohort study (diagnosis); Level of evidence, 3.
Based on a subset of participants enrolled in an ongoing ACL reconstruction clinical trial, AP knee laxity, 1-legged hop test, and KOOS were assessed at 3- and 5-year follow-up. Three-dimensional, T1-weighted MR images were collected at each visit. Both the volume and median SI of the healing graft were determined and used as predictors in a multiple regression linear model to predict the traditional outcome measures.
Graft volume combined with median SI in a multiple linear regression model predicted 1-legged hop test at both the 3- and 5-year follow-up visits (R(2) = 0.40, P = .008 and R(2) = 0.62, P = .003, respectively). Similar results were found at the 5-year follow-up for the KOOS quality of life (R(2) = 0.49, P = .012), sport/function (R(2) = 0.37, P = .048), pain (R(2) = 0.46, P = .017), and symptoms (R(2) = 0.45, P = .021) subscores, although these variables were not significant at 3 years. The multiple linear regression model for AP knee laxity at 5-year follow-up approached significance (R(2) = 0.36, P = .088).
The MR parameters (volume and median SI) used to predict ex vivo biomechanical properties of the graft in an animal model have the ability to predict clinical or in vivo outcome measures in patients at 3- and 5-year follow-up.
Results from this study may enhance clinical evaluation of graft health by relating the MR parameters of volume and median SI to traditional outcome measures and could potentially aid researchers in determining the appropriate timing for athletes to return to sport.
临床、功能和以患者为导向的结果通常用于评估前交叉韧带（ACL）损伤后治疗的疗效；然而，这些评估技术并未直接测量愈合过程中发生的生物力学变化。
确定在动物模型中用于预测移植物生物力学（即结构）特性的磁共振（MR）图像衍生的移植物体积和信号强度（SI）参数，是否与ACL重建后3年和5年患者常用的临床（膝关节前后[AP]松弛度）、功能（单腿跳）和以患者为导向的结果指标（膝关节损伤和骨关节炎结果评分[KOOS]）相关。
队列研究（诊断）；证据等级，3级。
基于一项正在进行的ACL重建临床试验的部分参与者，在3年和5年随访时评估膝关节AP松弛度、单腿跳测试和KOOS。每次随访时收集三维T1加权MR图像。确定愈合移植物的体积和中位SI，并将其用作多元线性回归模型中的预测因子，以预测传统结果指标。
在多元线性回归模型中，移植物体积与中位SI相结合，在3年和5年随访时均能预测单腿跳测试（R²分别为0.40，P = 0.008和R²为0.62，P = 0.003）。在5年随访时，KOOS生活质量（R² = 0.49，P = 0.012）、运动/功能（R² = 0.37，P = 0.048）、疼痛（R² = 0.46，P = 0.017）和症状（R² = 0.45，P = 0.021）子评分也有类似结果，尽管这些变量在3年时不显著。5年随访时膝关节AP松弛度的多元线性回归模型接近显著性（R² = 0.36，P = 0.088）。
在动物模型中用于预测移植物体外生物力学特性的MR参数（体积和中位SI），有能力预测3年和5年随访患者的临床或体内结果指标。
本研究结果通过将体积和中位SI的MR参数与传统结果指标相关联，可能会加强对移植物健康的临床评估，并可能有助于研究人员确定运动员重返运动的合适时机。
