Talar shift

Talar shift is a concept, sign and/or measurement describing a displacement of the talus in relation to the articular surface of the distal tibia and the malleolar end segment. The direction of the talar shift is further described in the medical literature and lateral talar shift receives the most attention.

Usage

The concept of talar shift can be used in the setting of ankle injuries as an indicator of ankle instability.

Measurement

The lateral talar shift is assessed on the mortise view of the ankle ^1-3.

Interpretation

The concept is that a lateral talar shift of ≥1 mm results in a significant decline of the tibiotalar contact surface area of ≥40% indicating ankle instability and this has an effect on the management ^1-4. Lateral talar shift is closely associated with an increase in the medial clear space ³.

History and etymology

The concept of lateral talar shift was described by Paul L Ramsey and William Hamilton in 1976 ^1,2.