Proximal tibial joint orientation line

The proximal tibial joint orientation line is a landmark used to assess angular deformities of the tibia and provide guidance for corrections.

In the frontal plane

The proximal tibial joint orientation line 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 joint and tarsal joint. The tibia is perpendicular to the beam. The beam is centered at the mid-tibial diaphysis.

The proximal tibial joint orientation line is the line joining the most distal aspects of the medial condyle and lateral condyle of tibia.

In the sagittal plane

For radiographic evaluation, the dog is positioned in lateral recumbency and a mediolateral radiograph is taken: the view includes the tibia, the stifle joint and the tarsal joint: the beam is centered on the mid-tibial diaphysis with the stifle and tarsus joints both at 90° flexion.

The proximal tibial joint orientation line is the line joining the cranial and caudal aspects of the articular surface of medial condyle, evidenced by the subchondral bone.