Codman triangle is a type of periosteal reaction seen with aggressive bone lesions. With aggressive lesions, the periosteum does not have time to ossify with shells of new bone (e.g. as seen in single layer and multilayered periosteal reaction), so only the edge of the raised periosteum will ossify.
The Codman triangle may be seen with aggressive lesions:
- Ewing sarcoma
- active aneurysmal bone cyst
- giant cell tumor
- chondrosarcoma (especially juxtacortical chondrosarcoma)
- malignant fibrous histiocytoma
History and etymology
It was first described by Ribbert in 1914 2. However, it is named for Ernest Amory Codman, who described it in the setting of Ewing sarcoma 3.
- 1. Wenaden AE, Szyszko TA, Saifuddin A. Imaging of periosteal reactions associated with focal lesions of bone. Clin Radiol. 2005 Apr;60(4):439-56. PubMed
- 2. Desai RV, Jain V, Katariya S. Codman's triangle in tubercular osteomyelitis. J Postgrad Med. 2002;48 (2): 157-8. Pubmed citation
- 3. Mallon WJ. E. Amory Codman AAOS Now. 2007 Jan/Feb. American Academy of Orthopaedic Surgeons