A Codman triangle is a type of periosteal reaction seen with aggressive bone lesions. The periosteum does not have time to ossify with shells of new bone (e.g. as seen in a single layer and multilayered periosteal reaction) in aggressive lesions, so only the edge of the raised periosteum will ossify.
The Codman triangle may be seen with the following 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 after the American surgeon Ernest Amory Codman (1869-1940), who described it in the setting of Ewing sarcoma 3,4.
- 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
- 4. Brand RA. Ernest Amory Codman, MD, 1869-1940. (2009) Clinical orthopaedics and related research. 467 (11): 2763-5. doi:10.1007/s11999-009-1047-8 - Pubmed