Milgram J W
Clin Orthop Relat Res. 1984 Jun(186):272-83.
A histopathologic study of a series of 346 resected femoral heads with gross osteonecrosis secondary to trauma, steroid therapy, idiopathic or other disease processes demonstrated the production of significant cartilaginous callus tissue at fracture clefts in 19 specimens (5.5%). Although subarticular fracture clefts were commonly present in such specimens, the formation of cartilaginous callus occurred only when one of the two opposing surfaces at the fracture cleft consisted of viable bone. Usually this was osseous tissue that originally had composed a portion of the infarct but had undergone revascularization. In another group of five cases from the same series, fragmentation of all tissue superior to the layer of cartilaginous callus had occurred by the time of surgery. The previously formed cartilaginous callus layer then became the actual weightbearing surface. Pathologically, callus must be differentiated from the cartilaginous tuft phenomenon of exposed intra-articular bone.
一项对346个因创伤、类固醇治疗、特发性或其他疾病过程继发严重骨坏死而切除的股骨头进行的组织病理学研究表明，在19个标本（5.5%）的骨折裂隙处产生了大量软骨痂组织。尽管此类标本中通常存在关节下骨折裂隙，但仅当骨折裂隙处相对的两个表面之一由存活骨组成时，才会形成软骨痂。通常这是原本构成梗死一部分但已经历血管再通的骨组织。在同一组系列中的另一组5例病例中，到手术时，软骨痂层上方的所有组织均已碎裂。先前形成的软骨痂层随后成为实际的负重表面。在病理上，痂必须与暴露的关节内骨的软骨簇现象相区分。
