Department of Radiology, Providence Hospital and Medical Center, Southfield, MI 48075, USA.
Skeletal Radiol. 2009 Nov;38(11):1111-4. doi: 10.1007/s00256-009-0729-3. Epub 2009 Jun 19.
While posterolateral knee dislocation is a rare entity, its identification has important implications. The invagination of skin seen in posterolateral knee dislocations is referred to as the "dimple sign" on physical exam. We report a case where the "dimple sign" was also demonstrated on magnetic resonance imaging. Failure to recognize this finding on imaging will render the knee irreducible, as a result of interposed tissues, until discovered by the orthopedic surgeon intraoperatively. The incarcerated medial capsule and medial collateral ligament could also be misinterpreted as torn meniscus, as occurred in our case.
虽然膝关节后外侧脱位较为少见，但明确诊断具有重要意义。体格检查时，可见膝关节后外侧脱位时出现的皮肤内陷，被称为“酒窝征”。我们报告了一例在磁共振成像上也显示“酒窝征”的病例。如果在影像学上未能识别这一发现，由于存在介入组织，膝关节将无法复位，直到骨科医生在手术中发现。嵌顿的内侧关节囊和内侧副韧带也可能被误诊为撕裂的半月板，就像我们的病例一样。
