Sivakumaran Thiru, Jaffer Rehana, Marwan Yousef, Hart Adam, Radu Arnold, Burman Mark, Martineau Paul A, Powell Tom
Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
McGill University Health Sciences Centre, McGill University, Montreal, Quebec, Canada.
Orthop J Sports Med. 2021 Oct 20;9(10):23259671211042603. doi: 10.1177/23259671211042603. eCollection 2021 Oct.
Nonanatomic placement of anterior cruciate ligament (ACL) grafts is a leading cause of ACL graft failure. Three-dimensional (3D) magnetic resonance imaging (MRI) femoral footprint localization could enhance planning for an ACL graft's position.
To determine the intra- and interobserver reliability of measurements of the ACL femoral footprint position and size obtained from 3D MRI scans.
Cohort study; Level of evidence, 3.
A total of 41 patients with complete ACL tears were recruited between November 2014 and May 2016. Preoperatively, a coronal-oblique proton-density fast spin echo 3D acquisition of the contralateral uninjured knee was obtained along the plane of the ACL using a 1.5T MRI scanner. ACL footprint parameters were obtained independently by 2 musculoskeletal radiologists (observers A and B). The distal and anterior positions of the center of the footprint were measured relative to the apex of the deep cartilage at the posteromedial aspect of the lateral femoral condyle, and the surface area of the ACL femoral footprint was approximated from multiplanar reformatted images. After 1 month, the measurements were repeated. Intraclass correlation coefficients (ICCs) were calculated to assess for intra- and interobserver reliability. Bland-Altman plots were produced to screen for potential systematic bias in measurement and to calculate limits of agreement.
The ICCs for intraobserver reliability of the ACL femoral distal and anterior footprint coordinates were 0.75 and 0.78, respectively, for observer A. For observer B, they were 0.75 and 0.74, respectively. The ICCs for interobserver reliability were 0.75 and 0.85 for the distal and anterior coordinates, respectively. Bland-Altman plots demonstrated no significant systematic bias. For surface area measurements, the intraobserver ICCs were 0.37 and 0.62 for observers A and B, respectively. The interobserver reliability was 0.60. Observer B consistently measured the footprints as slightly larger versus observer A (1.19 ± 0.27 vs 1 ± 0.22 cm, respectively; < .001).
Locating the center of the anatomic footprint of the ACL with 3D MRI showed substantial intra- and interobserver agreement. Interobserver agreement for the femoral footprint surface area was fair to moderate.
前交叉韧带（ACL）移植物的非解剖学放置是ACL移植物失败的主要原因。三维（3D）磁共振成像（MRI）对股骨足迹的定位可改善ACL移植物位置的规划。
确定从3D MRI扫描获得的ACL股骨足迹位置和大小测量的观察者内和观察者间可靠性。
队列研究；证据水平，3级。
2014年11月至2016年5月期间共招募了41例ACL完全撕裂的患者。术前，使用1.5T MRI扫描仪沿ACL平面获得对侧未受伤膝关节的冠状斜位质子密度快速自旋回波3D图像。ACL足迹参数由2名肌肉骨骼放射科医生（观察者A和B）独立获取。相对于外侧股骨髁后内侧深软骨的顶点测量足迹中心的远端和前部位置，并从多平面重组图像估算ACL股骨足迹的表面积。1个月后，重复测量。计算组内相关系数（ICC）以评估观察者内和观察者间的可靠性，并绘制Bland-Altman图以筛查测量中潜在的系统偏差并计算一致性界限。
观察者A对ACL股骨远端和前部足迹坐标的观察者内可靠性ICC分别为0.75和0.78。观察者B的分别为0.75和0.74。远端和前部坐标的观察者间可靠性ICC分别为0.75和0.85。Bland-Altman图显示无明显系统偏差。对于表面积测量，观察者A和B的观察者内ICC分别为0.37和0.62。观察者间可靠性为0.60。观察者B始终测量的足迹比观察者A略大（分别为1.19±0.27 vs 1±0.22 cm；P <.001）。
用3D MRI定位ACL解剖足迹中心显示观察者内和观察者间有高度一致性。股骨足迹表面积的观察者间一致性为中等。
