Miyawaki Motoko, Hensler Daniel, Illingworth Kenneth D, Irrgang James J, Fu Freddie H
Department of Orthopedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, Pittsburgh, PA, 15213, USA.
Knee Surg Sports Traumatol Arthrosc. 2014 May;22(5):1002-8. doi: 10.1007/s00167-014-2856-1. Epub 2014 Jan 29.
To evaluate magnetic resonance imaging (MRI) graft signal intensity after allograft double-bundle (DB) anterior cruciate ligament (ACL) reconstruction and determine the relationship between signal intensity and time from surgery.
Twenty-six patients with an intact graft on MRI after anatomic allograft DB ACL reconstruction up to 1 year post-operatively were included. All subjects underwent post-operative MRI using a 1.5-T magnet. Sagittal proton density-weighted images (PDWI) and sagittal T2-weighted images (T2WI) were analysed. Using the region-of-interest (ROI) function on imaging software, the anteromedial (AM) and posterolateral (PL) bundles of the graft and the posterior cruciate ligament (PCL) were outlined. Mean signal intensity of the three ROIs were recorded as absolute signal intensity. Signal intensity (SI ratio) was calculated based on the signal intensity of the PCL. Correlation coefficients were calculated to determine the relationship between signal intensity and time from surgery.
SI ratio of the PL bundle was higher than that of the AM bundle for both the PDWI (1.7 ± 1.5 vs. 2.5 ± 1.7, p < 0.05) and T2WI (1.3 ± 0.4 vs 1.6 ± 0.6, p < 0.05). There were weak correlations between AM SI ratio and time from surgery (r = 0.38, p < 0.05 on PDWI), and moderate correlations between PL SI ratio and time from surgery (r = 0.43, p < 0.05 on PDWI) (r = 0.44, p < 0.05 on T2WI).
The PL bundle displayed increased signal intensity compared to the AM bundle and based on previous studies may indicate a longer healing process. Plain MRI may be useful to assess graft healing after ACL reconstruction.
Retrospective case series, Level IV.
评估同种异体双束（DB）前交叉韧带（ACL）重建术后磁共振成像（MRI）移植物的信号强度，并确定信号强度与手术时间的关系。
纳入26例在解剖学同种异体DB ACL重建术后1年内MRI显示移植物完整的患者。所有受试者均使用1.5-T磁体进行术后MRI检查。分析矢状位质子密度加权图像（PDWI）和矢状位T2加权图像（T2WI）。使用成像软件上的感兴趣区域（ROI）功能，勾勒出移植物的前内侧（AM）束和后外侧（PL）束以及后交叉韧带（PCL）。记录三个ROI的平均信号强度作为绝对信号强度。基于PCL的信号强度计算信号强度（SI比值）。计算相关系数以确定信号强度与手术时间的关系。
对于PDWI（1.7±1.5对2.5±1.7，p<0.05）和T2WI（1.3±0.4对1.6±0.6，p<0.05），PL束的SI比值均高于AM束。AM SI比值与手术时间之间存在弱相关性（PDWI上r = 0.38，p<0.05），PL SI比值与手术时间之间存在中度相关性（PDWI上r = 0.43，p<0.05）（T2WI上r = 0.44，p<0.05）。
与AM束相比，PL束显示出更高的信号强度，根据先前的研究可能表明愈合过程更长。普通MRI可能有助于评估ACL重建术后移植物的愈合情况。
回顾性病例系列，IV级。
