Russell R D
J Foot Surg. 1980 Fall;19(3):159-61.
In summary, slow union can be caused from impaired blood supply, delayed union by inadequate immobilization, whether external or internal, and infection. Nonunion as well as delayed union may be caused by prolonged movement and interposition of soft tissue. Slow union and delayed union with too early cessation of immobilization cause nonunion. It may be said that if a fracture has not united within 4 months, delayed union is occurring. After 8 months, nonunion or pseudoarthrosis occurs (4).
总之，愈合缓慢可能由血液供应受损、固定不充分（无论是外固定还是内固定）以及感染引起。骨不连和延迟愈合可能由长时间活动和软组织嵌入导致。愈合缓慢和过早停止固定导致的延迟愈合会引起骨不连。可以说，如果骨折在4个月内未愈合，则发生延迟愈合。8个月后，会发生骨不连或假关节形成（4）。
