Department of Radiology, Loma Linda University Medical Center, Loma Linda, California, USA.
Department of Orthopaedic Surgery, Loma Linda University Medical Center, Loma Linda, California, USA.
Orthop J Sports Med. 2015 Aug 3;3(8):2325967115597641. doi: 10.1177/2325967115597641. eCollection 2015 Aug.
Diagnosis of partial anterior cruciate ligament (ACL) tears is difficult on magnetic resonance imaging (MRI), particularly the isolated tears of the posterolateral bundle.
To describe 2 MRI signs of partial ACL tear involving the posterolateral bundle on conventional knee MRI sequences, specifically, the "gap" and "footprint" signs.
Case-control study.
We retrospectively reviewed the MRI appearance of the ACL in 11 patients with arthroscopically proven partial ACL tears isolated to the posterolateral bundle, as well as in 10 patients with arthroscopically proven intact ACLs, and evaluated for the presence of gap and/or footprint signs.
There was high degree of sensitivity and specificity associated with the MRI findings of "gap" and "footprint" signs with arthroscopically proven isolated posterolateral bundle tears.
Gap and footprint signs are suggestive of posterolateral bundle tear of the ACL, and the presence of 1 or both of these imaging findings should alert the radiologist to the possibility of a posterolateral bundle tear.
在磁共振成像（MRI）上，部分前交叉韧带（ACL）撕裂的诊断较为困难，特别是后外侧束的单独撕裂。
描述常规膝关节 MRI 序列中涉及后外侧束的部分 ACL 撕裂的 2 种 MRI 征象，即“间隙”和“压迹”征象。
病例对照研究。
我们回顾性分析了 11 例经关节镜证实的单独后外侧束部分 ACL 撕裂患者的 MRI 表现，以及 10 例经关节镜证实的 ACL 完整患者的 MRI 表现，并评估了间隙和/或压迹征象的存在。
与关节镜证实的单独后外侧束撕裂相比，MRI 发现的“间隙”和“压迹”征象具有较高的敏感性和特异性。
间隙和压迹征象提示 ACL 的后外侧束撕裂，如果存在 1 种或 2 种这些影像学表现，放射科医生应警惕后外侧束撕裂的可能。
