Saito S, Ohzono K, Ono K
Department of Orthopaedic Surgery, Osaka University Medical School, Japan.
Clin Orthop Relat Res. 1988 Jun(231):35-50.
Minimal osteonecrosis (MON) is a small and eccentrically localized lesion of osteonecrosis (ON) of the femoral head. This form of ON shows clinically benign features, but may be indicative of the pathomechanism of ON. Of 180 patients (275 hips) with ON, 15 patients (19 hips) were found to have MON. Based on the geography of the femoral head, the lesions were grouped into four types: anterior (seven hips), superior (six hips), medial (five hips), and lateral (one hip). When the location of the lesion was compared with the normal vascular anatomy, a close correlation between the location and the segmental blood supply in the femoral head became evident. Histologic findings showed localized infarction of the trabeculae and bone marrow, but no evidence suggesting repeated episodes of infarction, which is an essential feature of typical ON. From these findings, MON may be a segmental infarct within the femoral head. Interruption of the blood flow may possibly occur not in the main trunk but in the terminal branch of the lateral epiphyseal or superior metaphyseal artery; such as ischemic event is probably a single brief attack, leading to this form of infarction in contrast to typical ON developing with prolonged or recurrent obstructions.
微小骨坏死（MON）是股骨头骨坏死（ON）中一种小的、偏心定位的病变。这种形式的骨坏死在临床上表现为良性特征，但可能提示骨坏死的发病机制。在180例（275髋）骨坏死患者中，发现15例（19髋）患有微小骨坏死。根据股骨头的部位，病变分为四种类型：前部（7髋）、上部（6髋）、内侧（5髋）和外侧（1髋）。当将病变部位与正常血管解剖结构进行比较时，病变部位与股骨头节段性血供之间的密切相关性变得明显。组织学检查结果显示小梁和骨髓局部梗死，但没有证据表明存在反复梗死发作，而反复梗死发作是典型骨坏死的一个基本特征。根据这些发现，微小骨坏死可能是股骨头内的节段性梗死。血流中断可能不是发生在主干，而是发生在外侧骨骺或上干骺端动脉的终末分支；这种缺血事件可能是单次短暂发作，导致了这种形式的梗死，这与因长期或反复阻塞而发展的典型骨坏死形成对比。
