A cyma line refers to the union of two curved lines in architecture. In a radiological context it refers to the smooth joining of the midtarsal joint lines of the talonavicular and calcaneocuboid joints on both AP and lateral views.
A disruption of the cyma line can indicate true shortening of the calcaneus or rotation of the talus relative to the calcaneus as seen in pes planus, in which the medial arch is flattened.
- 1. Zhou Y, Zhou B, Liu J, Tan X, Tao X, Chen W, Tang K. A prospective study of midfoot osteotomy combined with adjacent joint sparing internal fixation in treatment of rigid pes cavus deformity. Journal of orthopaedic surgery and research. 9: 44. doi:10.1186/1749-799X-9-44 - Pubmed
- 2. Miller SJ. End-stage flatfoot. Diagnosis and conservative and surgical management. Journal of the American Podiatric Medical Association. 77 (1): 42-5. doi:10.7547/87507315-77-1-42 - Pubmed