Department of Orthopaedic Surgery, Kyushu University, Fukuoka, Japan.
Clin Orthop Surg. 2012 Sep;4(3):173-80. doi: 10.4055/cios.2012.4.3.173. Epub 2012 Aug 14.
A subchondral insufficiency fracture (SIF) of the femoral head is a recently proposed concept, which needs to be differentiated from osteonecrosis. Clinically, SIF has generally been observed in the osteoporotic elderly women or renal transplant recipients. Radiographical changes are not obvious in its early phase, however, some cases undergo subchondral collapse (crescent sign). On the T1-weighted magnetic resonance images, a low intensity band is one of the characteristic imaging appearances, which corresponds histologically to the fracture line and associated fracture repair tissue. Therefore, the shape of the low intensity band generally tends to be irregular, disconnected, and convex to the articular surface. The prognosis of SIF is not clearly established. Some cases show resolution of the symptoms by the conservative treatments, while other cases show rapid progression of the collapse such as rapidly progressive arthrosis of the hip.
股骨头的软骨下不全骨折（SIF）是一个最近提出的概念，需要与骨坏死区分开来。临床上，SIF 一般发生在骨质疏松的老年女性或肾移植受者中。早期影像学改变不明显，但有些病例会出现软骨下塌陷（新月征）。在 T1 加权磁共振图像上，低信号带是其特征性影像学表现之一，在组织学上对应于骨折线和相关的骨折修复组织。因此，低信号带的形状通常倾向于不规则、不连续，并且向关节面凸起。SIF 的预后尚不清楚。一些病例通过保守治疗症状缓解，而另一些病例则迅速进展为塌陷，如髋关节进行性骨关节炎。
