CT scans and radiographs have limited ability to depict which type of coalition in the calcaneonavicular region?

CT scans and radiographs have limited ability to depict which type of coalition in the calcaneonavicular region?

• A. Fibrous coalition
• B. Osseous coalition
• C. Cartilaginous coalition
• D. Mixed coalition

Answer: (A)

Coalitions between the calcaneus and navicular can be fibrous, cartilaginous, osseous, or mixed, and the visibility on imaging depends on the tissue making up the bridge. Osseous coalitions create a solid bone bridge, so they’re usually obvious on radiographs and CT. Cartilaginous coalitions lack bone bridging, so they’re not clearly seen as a discrete structure on these studies and may only show subtle joint irregularities. Fibrous coalitions are made of soft tissue bridging with no mineralized bridge, making them particularly difficult to detect on X-ray or CT because there’s little density difference from surrounding tissues. MRI better characterizes these fibrous connections. Thus, CT scans and radiographs have limited ability to depict fibrous coalitions in the calcaneonavicular region.

Coalitions between the calcaneus and navicular can be fibrous, cartilaginous, osseous, or mixed, and the visibility on imaging depends on the tissue making up the bridge. Osseous coalitions create a solid bone bridge, so they’re usually obvious on radiographs and CT. Cartilaginous coalitions lack bone bridging, so they’re not clearly seen as a discrete structure on these studies and may only show subtle joint irregularities. Fibrous coalitions are made of soft tissue bridging with no mineralized bridge, making them particularly difficult to detect on X-ray or CT because there’s little density difference from surrounding tissues. MRI better characterizes these fibrous connections. Thus, CT scans and radiographs have limited ability to depict fibrous coalitions in the calcaneonavicular region.