Department of Orthopaedic Sports Medicine, Technical University of Munich, Munich, Germany.
Department of Radiology, Technical University of Munich, Munich, Germany.
Am J Sports Med. 2020 Jul;48(8):1929-1936. doi: 10.1177/0363546520919986. Epub 2020 May 14.
In current magnetic resonance imaging (MRI) of the knee, injuries to the anterolateral ligament complex (ALC) and the Kaplan fibers (KFs) are not routinely assessed. As ruptures of the KFs contribute to anterolateral rotatory instability in the anterior cruciate ligament-deficient knee, detecting these injuries on MRI may help surgeons to individualize treatment.
To visualize the KFs on 3-T MRI and to conduct a layer-by-layer dissection of the ALC.
Descriptive laboratory study.
Ten fresh-frozen human cadaveric knees (mean ± SD age, 72 ± 8.5 years) without history of ligament injury were used in this study. Before layer-by-layer dissection of the ALC, MRI was performed to define the radiologic anatomy of the KFs. A coronal T1-weighted 3-dimensional turbo spin echo sequence and a transverse T2-weighted turbo spin echo sequence were obtained. Three-dimensional data sets were used for multiplanar reconstructions.
KFs were identified in 100% of cases on MRI and in anatomic dissection. The mean length of the proximal and distal KFs was 17.9 ± 3.6 mm and 12.4 ± 6.5 mm, respectively. On MRI, the distance from the lateral femoral epicondyle to the proximal KFs was 35.9 ± 6.9 mm and to the distal KFs, 16.6 ± 4.1 mm; in anatomic dissection, the distances were 41.4 ± 8.1 mm for proximal KFs and 28.2 ± 8.1 mm for distal KFs. The distance from the lateral joint line to the proximal KFs was 63.5 ± 7.6 mm and to the distal KFs, 45.3 ± 3.7 mm. Interobserver reliability for image analysis was excellent for all measurements.
KFs can be consistently identified on MRI with use of 3-dimensional sequences. Subsequent anatomic dissection confirmed their close topography to the superior lateral genicular artery. For clinical implications, the integrity of the KFs should be routinely reviewed on MRI scans.
As ruptures of the KFs contribute to anterolateral rotatory instability, accurate visualization of the KFs on MRI may facilitate surgical decision making for additional anterolateral procedures in the anterior cruciate ligament-deficient knee.
在当前膝关节的磁共振成像（MRI）中，通常不会评估前外侧韧带复合体（ALC）和 Kaplan 纤维（KF）的损伤。由于 KF 的撕裂会导致前交叉韧带缺失膝关节的前外侧旋转不稳定，因此 MRI 上检测到这些损伤可能有助于外科医生个体化治疗。
在 3T MRI 上可视化 KF，并对 ALC 进行逐层解剖。
描述性实验室研究。
本研究使用了 10 个无韧带损伤病史的新鲜冷冻人尸体膝关节（平均年龄±标准差，72±8.5 岁）。在对 ALC 进行逐层解剖之前，进行了 MRI 以定义 KF 的影像学解剖结构。获得了冠状 T1 加权 3 维涡轮自旋回波序列和横断 T2 加权涡轮自旋回波序列。使用三维数据集进行多平面重建。
在 MRI 和解剖学解剖中均能在 100%的病例中识别出 KF。近端和远端 KF 的平均长度分别为 17.9±3.6mm 和 12.4±6.5mm。在 MRI 上，从外侧股骨髁到近端 KF 的距离为 35.9±6.9mm，到远端 KF 的距离为 16.6±4.1mm；在解剖学解剖中，近端 KF 的距离为 41.4±8.1mm，远端 KF 的距离为 28.2±8.1mm。从外侧关节线到近端 KF 的距离为 63.5±7.6mm，到远端 KF 的距离为 45.3±3.7mm。观察者之间对所有测量值的图像分析的可靠性均为优秀。
使用 3 维序列，在 MRI 上可以一致地识别 KF。随后的解剖学解剖证实了它们与上外侧髁动脉的紧密关系。对于临床意义，KF 的完整性应在 MRI 扫描中常规复查。
由于 KF 的撕裂会导致前外侧旋转不稳定，因此 MRI 上准确显示 KF 可能有助于在 ACL 缺失膝关节中进行额外的前外侧手术时做出手术决策。
