Myositis ossificans in children: a review

Abstract

The formation of lamellar bone in the soft tissues, where bone normally does not exist, is called myositis ossificans. However, it would be more accurate to describe as myositis ossificans the involvement of skeletal muscles and as ectopic or heterotopic ossification the involvement of soft tissues in general. The lesion is subdivided in genetic and non-genetic or acquired types. Myositis or fibrodysplasia ossificans progressiva is a debilitating rare genetic disorder. Clinical suspicion of the disease in the newborn on the basis of malformed great toes may lead to early clinical diagnosis, confirmatory diagnostic genetic testing and avoidance of iatrogenic harmful procedures. Acquired lesions involve the neurogenic myositis ossificans and the non-neurogenic disorder. The latter is defined either as circumscribed myositis ossificans that is post-traumatic or as idiopathic/pseudomalignant myositis ossificans that is non-traumatic and may be a form fruste of fibrodysplasia ossificans progressiva. Ossification in fibrodysplasia ossificans progressiva is irreversible, unlike other forms of heterotopic ossification. In this retrospective study, a total of 22 children with myositis ossificans treated in a 20-year period were identified and classified. Two patients were diagnosed with myositis/fibrodysplasia ossificans progressiva, one with neurogenic myositis ossificans, one with idiopathic/pseudomalignant myositis ossificans and 18 patients with circumscribed myositis ossificans. The clinical features, imaging and histological findings as well as treatment modalities and complications of myositis ossificans in our patients are presented and discussed.

Fibrodysplasia Ossificans Progressiva (Stoneman Syndrome) – A Rare Skeletal Dysplasia

“…[5] e great toe malformations such as short metatarsals and hallux valgus were thought to exist from birth and may be a key to an early diagnosis. [6] Patients can also develop acute exacerbations associated with soft-tissue swellings and pain at the affected sites. e heterotopic ossification replaces muscles and connective tissues in the body in a characteristic anatomical pattern.…”

MRI Findings of Early Myositis Ossificans without Calcification or Ossification

“…Past experience indicates that the appearance of early MO without calcification or ossification in MRI may confuse radiologists and lead to misdiagnosis of the mass as sarcoma, metastasis, lymphoma, or benign conditions such as infection and proliferative myositis [ 9 , 21 ]. First, the prominent surrounding muscle edema feature is not usually noted in sarcomas and could be an important diagnostic finding [ 3 ].…”

Imaging of Pediatric Lower Limb Sports Injuries

“…Myositis ossificans, also known as heterotopic ossification, is the formation of mature bone in soft tissue in association with inflammation after trauma, neurologic injury, or disease. 62 Here we focus on myositis ossificans occurring after trauma (i.e., myositis ossificans circumscripta). Patients present with a tender swelling with pain during movement and increased joint stiffness.…”

“…In the lower extremity, this occurs most often in the muscles around the pelvis and upper leg. 62 The exact pathogenesis is unknown, but three Last is the formation of mature lamellar bone. 63 The imaging appearances change with the changing histopathology.…”