Border collie, female intact, 11 years of age.

HBC two hours ago.

Presented in shock, at clinical examination crepitus in the right limb.

Radiographic examination of the thorax and of the right hind limb was performed.

Thorax was radiologically normal.

Craniocaudal and mediolateral view of the right tibia were taken

Radiologic findings

• Bandage is superimposed to the distal limb, soft tissue are not well assessable for presence of gas inclusions.
• There are obvious multiple fractures lines and fragments in the distal tibial diaphysis. Mutiple cortical (butterfly) fragments are only mildly dislocated, there is a mild angulation lateral of the distal limb and minimal shortening.
• One of the lucent fractures lines is visible on the ML view running from dorsoproximal to caudodistal in close association to the tibiotarsal joint space.
• Is that all?

Additional mineral opacity separated from the lateral tibial pleateau.

Severe smooth and solid new bone proliferation periarticular on the tarsometatarsal joint.

Radiologic diagnosis

Complete, multiple fragment fracture of the right distal tibial diaphysis, with a suspected articular involvement of the tibiotarsal joint.

Fragment from the lateral tibial condyle, possible avulsion.

Incidental findings: Severe chronic osteoarthritis of the tarsometatarsal joint.

Close up of the fragmented lateral tibial condyle visible on both views

Comments

The lateral collateral ligament crosses the joint cavity and passes over the tendon of the origin of the M. popliteus. It ends distally on the head of the fibula, with a few fibers going to the adjacent lateral condyle of the tibia. Probably an avulsion from the collateral ligament would have displaced the fragment proximally and would have involved the fibular head.

The area of the fragmented lateral tibial condyle is in anatomical proximity with multiple structures: Some fibers of the lateral collateral ligament, the M. extensor digitorum longus (arises in the extensor fossa on the lateral epicondyle of the femur and passes through the sulcus extensorius of the tibia), the M. peroneus longus (arising from the lateral condyle of the tibia, the fibular collateral ligament of the femorotibial joint and the proximal end of the fibula). An avulsion from tearing on one of these structures is possible.

Post OP Study

In surgery the fissure of the distal tibia was classified not articular and closed.

No instability was detected neither in the stifle joint nor in the tibiotarsal joint.

The tibial plateau was fixed with a pin and a lag screw from lateral.

The tibial fracture was fixed with an external fixator with multiple pins and halfpins.