Case of the week 6.10.19
Publication Date: 2019-06-10
History
12 weeks old toy poodle. Right carpal varus
4 images
Findings
Orthogonal radiographs of both antebrachia.
Right antebrachium: The mid and distal radius curves medially so that its distal articular end is not articulating with the carpus and protrudes medially distally relative to the antebrachiocarpal joint. Also associated with the abnormally located distal end of the radius, there are two carpal bones and a small rudimentary bone of digit one. The mid and distal aspects of the ulna are wider in diameter than the left. There are numerous open physes. The lateral and medial ossification centers of the humeral condyle are not fused. There is rotation of the carpus and manus at the level of the antebrachiocarpal joint.
Left antebrachium: The lateral and medial ossification centers of the humeral condyle are not fused, and there are numerous open physes.
Diagnosis
- The changes to the right antebrachium are consistent with a variation of ectrodactyly, a congenital/developmental abnormality.
- Given the reported age of the patient (12 weeks), the incomplete ossification of the humeral condyle would be delayed/incomplete (expected ossification by 10 weeks), or the patient is younger than reported.
Discussion
Here is a good open access reference if you are interested in ectrodactyly
https://www.merckvetmanual.com/musculoskeletal-system/congenital-and-inherited-anomalies-of-the-musculoskeletal-system/congenital-and-inherited-anomalies-of-the-musculoskeletal-system-in-small-animals
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