The talar beak sign is seen in cases of tarsal coalition, and refers to a superior projection of the distal aspect of the talus. It is most frequently encountered in talocalcaneal coalition 1-2. It is thought to result from abnormal biomechanic stresses at the talonavicular joint.
It needs to be distinguished from :
- an osteophyte due to degenerative change at the talonavicular joint
- the talar ridge found more proximally at the site of insertion of the ankle capsule1. The normal talar ridge is several millimeters high and has a straight or slightly convex, graded slope proximally, and a straight, sharp margin distally 2
- 1. Crim JR, Kjeldsberg KM. Radiographic diagnosis of tarsal coalition. AJR Am J Roentgenol. 2004;182 (2): 323-8. AJR Am J Roentgenol (full text) - Pubmed citation
- 2. Resnick D. Talar ridges, osteophytes, and beaks: a radiologic commentary. Radiology. 1984;151 (2): 329-32. Radiology (abstract) - Pubmed citation
- 3. Crim JR, Kjeldsberg KM. Radiographic diagnosis of tarsal coalition. AJR Am J Roentgenol. 2004;182 (2): 323-8. AJR Am J Roentgenol (full text) - Pubmed citation