Myositis ossificans circumscripta of the triceps muscle in a Rottweiler dog

Abstract

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.

Suspected self-limiting myositis ossificans of the patella tendon

“…Serum biochemistry, including creatine kinase enzyme, can also increase the suspicion of muscle injury 6 . Mature myositis ossificans appears as well-marginated bone on plain radiographs, as seen in our case report 4,[6][7][8][9] . No surgical biopsy was performed in this case to confirm the diagnosis, due to the clinical and radiographic improvement.…”

“…Due to the self-limiting soft tissue ossification, myositis ossificans was the presumed diagnosis. To our knowledge, this is the first report of a self-resolving myositis ossificans affecting the patellar tendon, which did not require surgical treatment 3,4,[6][7][8][9] . Based on this case, myositis ossificans should be a differential diagnosis for dogs presenting with lameness and conservative management could be attempted.…”

“…Its' origin can be idiopathic or secondary to trauma. It can present in humans and animals [1][2][3][4] . Myositis ossificans is rarely reported in dogs and often seen in the limb muscles.…”

Bilateral fibrodysplasia ossificans affecting the masticatory muscles and causing irreversible trismus in a domestic shorthair cat

“…Periosteal new bone formation was described in human and canine myositis ossificans circumscripta. 22–29 The lack of consistent inflammatory features on biopsied material and the bilateral multifocal asymmetric distribution of lesions are not compatible with myositis ossificans circumscripta. 22,27–29…”

Case report: Focal heterotopic ossification in paravertebral muscles as a cause of neurogenic lameness in a dog

“…Another excision will follow if necessary ( 20 ). HO in dogs is rare, with most reported cases affecting hip joints and the appendicular muscles ( 9 , 10 , 21 , 22 ). One similar report of HO close to the cervical spine in a dog with lameness was published, but no connection with neural structures was mentioned ( 8 ).…”