Gissane angle

Gissane angle,also known as the "critical angle of Gissane", is an angulara measurement made directly inferioron lateral foot radiographs used to evaluate the severity of a calcaneal fractures.

Measurement

The Gissane angle is measured by drawing lines along the superior surfaces of the talus. It is formed byanterior process and the downward and upward slopesposterior facet of the calcaneal superior surfacecalcaneus to meet at the sinus tarsi¹. It is better seenproperly measured on a the lateral plain film offoot radiograph, but can also be measured on lateral ankle radiographs, allowing for the calcaneus and hindfootslight differences in projection. Its

Interpretation

The normal valueGissane angle is usually between 120° and 145°¹. There is relatively wide variation in the size of the ankle between individuals but there is relatively little difference between the left and right feet of individual patients ². 

The Gissane angle, together with the Böhler’s angle, are commonlyis used to evaluate the severity of a calcaneal fracture and the goal of surgical treatment is to restore these angles to normal values, though the Gissane angle is less useful than Böhler angle, and so is less frequently used ⁴.

History and etymology

William Gissane (1898-1981), an Australian by birth, was a professor of orthopaedics, and is remembered as a pioneer of traumatology. He was the first clinical director of the Birmingham Accident Hospital, regarded as the first dedicated trauma centre in the world ⁵³.