Buttress Periosteal Reaction

Buttress or buttressed periosteal reaction refers to beaklike solid periosteal new bone formation that can be seen with benign and malignant lesions. It is the interrupted version of the solid periosteal reaction.

It can be seen in the setting of saucerization of bone by a non-mineralized tumor (e.g., periosteal chondroma), whereby the periosteum reacts adjacent to the saucerization, giving a buttressed appearance.

The buttressed appearance can also be seen with an expanding intramedullary process (e.g., aneurysmal bone cyst) that breaks through an area of solid periosteal reaction. This may or may not represent malignant transformation of a previously benign process.

The buttress periosteal reaction should be distinguished from the Codman triangle, which is seen at the periphery of a lesion as an elevation of interrupted periosteum with one or more layers of new bone.

References

• Miller TT. Bone tumors and tumorlike conditions: analysis with conventional radiography. Radiology. 2008 Mar;246(3):662-74.
• Ragsdale BD, Madewell JE, Sweet DE. Radiologic and pathologic analysis of solitary bone lesions. Part II: periosteal reactions. Radiol Clin North Am. 1981 Dec;19(4):749-83.