Presentation
Acute severe cervical spine pain on the background of known degenerative disease.
Patient Data
Large amount of low T1 and low T2 signal periodontoid material with widening of the median atlantoaxial joint and erosions of the dens. Marrow edema within the dens, anterior arch of C1, the lateral masses of C1 and C2, and within the left occipital condyle. Thin circumferential fluid within the epidural from C1 to C3 (best seen on STIR images). Background multilevel cervical spine disc and facet joint degeneration including C4-7 disc ankylosis and C3-4 canal stenosis due to combination of disc-osteophyte complex and ligamentum flavum hypertrophy.
Chondrocalcinosis of the TFCC and osteoarthritic-like appearance of the 2nd and 3rd MCP joints bilaterally. There is also radiocarpal and intercarpal arthropathy, particularly on the right with prominent geode cyst formation. This distribution is unusual for typical osteoarthritis and is most suggestive of CPPD arthropathy.
Case Discussion
A case of acute CPPD of the atlantoaxial joint with related marrow edema and epidural fluid. The low signal thickening of the periodontoid tissues, along with the characteristic hand and wrist features of CPPD, help to make the diagnosis. Acute presentations of CPPD at this joint is often termed "crowned dens syndrome" referring to the calcification for periodontoid ligaments on CT.