What is your diagnosis? Dorsal subluxation of the talus with bony opacities associated with the distal portion of the tibia

Bilateral dorsal rotation of the talus with tibiotarsal, talocalcaneal, and proximal intertarsal joint subluxation in an alpaca

CASE DESCRIPTION

A 14-month-old female alpaca presented with a 3-week history of acute left hind limb lameness and swelling of the left tarsal region.

CLINICAL FINDINGS

Radiography revealed intermittent dorsal rotation of the talus with tibiotarsal, talocalcaneal, and proximal intertarsal joint subluxation.

TREATMENT AND OUTCOME

In an attempt to stabilize the talus, screws were placed in the distomedial aspect of the talus and the plantaromedial aspect of the central tarsal bone, and a stainless-steel wire was placed around the screws in a figure-eight pattern. The screw head of the proximal screw broke within 4 weeks after surgery, but subluxation did not recur, and the lameness resolved. Seven months later, the same condition was diagnosed in the opposite hind limb and was treated similarly. Implants remained intact on this side, but the animal started to show signs of pain and inability to flex the tarsal joint, prompting removal of the distal screw. Subsequently, the animal became sound and produced 2 healthy crias, but was euthanatized 4 years after the second surgery because of coccidiosis.

CLINICAL RELEVANCE

Dorsal rotation of the talus with tibiotarsal, talocalcaneal, and proximal intertarsal joint subluxation is a sporadic condition in New World camelids. This report provides the first account of successful treatment by surgical stabilization of the medial aspect of the proximal intertarsal joint.