Summary
A 20-month-old male Rottweiler dog was presented with the complaint of chronic right
forelimb lameness that was unresponsive to conservative treatment. Physical examination
allowed for the topographical identification of the source of the problem as a firm
enlargement of the soft tissues that was partially movable from humeral bone and compatible
with an alteration of the triceps brachii muscle. Radiographic images showed signs
that were highly suggestive of myositis ossificans. Computed tomography allowed for
a more accurate characterization of the lesion, to exclude involvement of the elbow
joint and humeral bone, and to localize anatomically the lesion in the caput accessorium
and longum of the triceps brachii muscle. Surgical excision of the ossified portion
of the triceps muscle was performed. Histological examination of the excised tissue
substantiated the diagnosis of myositis ossificans. A one year clinical and radiographic
follow-up examination showed a complete recovery, with no evidence of complications
or recurrence. Despite myositis ossificans in dogs having previously been identified
in the hindlimbs, this case of myositis ossificans circumscripta of the triceps muscle
suggests that it may also occur in the muscles of the forelimb.
Keywords
Myositis ossificans - triceps muscle - lameness - dog