Overview

The AP mortise ankle radiograph visualizes the ankle joint with the mortise open by internally rotating the foot approximately 15 degrees. This projection displays the tibial plafond talar dome and fibular relationship. It is standard for ankle trauma and arthritis evaluation.

Technique

Internally rotate the foot to align the malleoli parallel to the detector and center to the ankle joint. Ensure the entire mortise is included and use appropriate exposure. Immobilize the limb to reduce motion artifact.

Clinical Indications

AP mortise is indicated for trauma suspected fracture and evaluation of joint congruity. It helps detect talar dome lesions and syndesmotic widening. Additional lateral and oblique views complement the mortise projection.

Image Assessment

Assess joint space symmetry and inspect for cortical disruption of the malleoli and talus. Evaluate for talar tilt and syndesmotic injury. Document findings and recommend orthopedic consultation when indicated.