Mechanical lateral proximal tibial angle

The mechanical lateral proximal tibial angle is a measurement used to assess angular deformities of the tibia and provide guidance for corrections. It is determined from a craniocaudal or caudocranial radiograph, or multiplanar reconstructed CT images of the tibia.

For radiographic evaluation, the view includes the entire tibia, stifle and tarsal joints. The tibia is perpendicular to the beam. The beam is centered at the mid-tibial diaphysis. Positioning is considered satisfactory if :

• the medial and lateral femur corticals passes through the middle of the sesamoid bones of the gastrocnemius muscle.

• the medial aspect of the calcaneus and the intermediate ridge of tibial cochlea are aligned.

The mechanical lateral proximal tibial angle is the angle between the mechanical tibial axis and the proximal tibial joint orientation line in the frontal plane, in the lateral aspect of the tibia.