Mechanical medial distal tibial angle

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

The following results have been published for the mechanical medial distal tibial angle :

• Small breeds : 98,1 +/- 4,4° (Radiography) (Olimpo et al. 2016)

• Small breeds : 90° (75–99) (Radiography) (Garnoeva et al. 2018)

• Chihuahua : 97,2 +/- 3,7° (Radiography CrCd) ; 93,4 +/- 1,1 (Radiography CdCr) (Phetkaew et al. 2018)

• English Bulldog : 91,34 +/- 2,98° (CT (Lusetti et al. 2017)

• Chihuahua : 94,3 +/- 7,8° (CT) (Phetkaew et al. 2018)