Bridging Myositis Ossificans After Supracondylar Humeral Fracture in a Child: A Case Report

Background: Myositis ossificans is an uncommon complication of trauma and surgery, defined as ossifying changes in a non-osseous tissue such as muscles. It happens after tissue injury, with or without fractures. When myositis ossificans occurs around a joint, it can cause ankylosis, leading to complete dysfunction of the joint. Though it has been described in most parts of the body, bridging myositis ossificans involving the elbow joint were scarcely reported.Case Presentation: We report a severe case of myositis ossificans after a supracondylar humerus fracture in a 9-year-old child. In this case a palpable painless mass appeared following the fracture and surgical trauma. Ultrasound or X-ray is of significant diagnostic value. The brachialis was completely ossified and formed a bony bridge around the elbow, causing complete ankylosis. The bone mass was surgically removed through a bilateral less-invasive approach with less surgical trauma 9 months after initial presentation. we applied bone wax to the fresh bone wounds to prevent the formation of hematocele. Indomethacin, a non-steroidal anti-inflammatory drug, was administered after the operation to suppress bone proliferation in our case. Our patient had the best possible functional status and no recurrence at 2 years' follow-up.Conclusion: Elbow myositis ossificans in children may mainly affects the brachialis. A bilateral less-invasive approach is sufficient to remove the bone mass with less surgical trauma. This case also provides a new reference for the treatment of myositis ossificans after the elbow injuries.

Case Report: Unusual Presentation of Myositis Ossificans of the Elbow in a Child Who Underwent Excessive Postoperative Rehabilitation Exercise

Traumatic myositis ossificans (MO) is an unusual complication after muscle injury and is predominantly seen in young adults and adolescents. Pediatric MO cases are even rarer. We report an 8-year-old girl who was diagnosed with a lateral humeral condyle fracture. She was treated surgically, and her elbow joint was fixed with plaster. Rehabilitation exercise was administered 1 month after the operation. Due to the wrong exercise method, a palpable bony mass appeared around the elbow 1 month later. The clinical radiological diagnosis showed MO, and conservative treatment was administered. After 3 years of follow-up, the affected limb functioned well, with no sign of recurrence. Here, we report this long-term follow-up case of MO resulting from excessive rehabilitation exercise.

Role of MRI in the differentiation of early myositis ossificans and soft-tissue sarcoma

Myositis ossificans (MO) is a benign, self-limiting condition characterized by abnormal ossification of soft tissue. MO occurs most commonly in the setting of trauma, however can also develop spontaneously. A peripheral rim of zonal calcification within the affected region represents the classic late-stage appearance and is considered virtually pathognomonic. During the early stages of MO development, diagnostic uncertainty may, however, arise as its imaging features can demonstrate overlap with malignant lesions such as soft-tissue sarcoma. This may lead to unnecessary further investigations, including image-guided biopsy. Recognition of the imaging features of early MO using magnetic resonance imaging (MRI) can provide the radiologist with more diagnostic certainty and help obviate the need for unnecessary investigation of this benign entity. This case offers an example of how MRI can achieve this diagnosis during the early multimodality investigation of an indeterminate soft-tissue mass.

Post-traumatic myositis ossificans: a benign lesion that simulates malignant bone and soft tissue tumours

Myositis ossificans (MO) is a benign bone formation in an extra-skeletal location. The most common subtype of MO, the post-traumatic, usually develops in young males after a traumatic event or sports injury. MO may simulate malignant bone lesions such as extra-skeletal or surface osteosarcomas, or soft tissue sarcomas such as synovial sarcoma or undifferentiated pleomorphic sarcoma. In the early phase the diagnosis of MO is challenging because imaging and histopathological findings may be non-characteristic. Detailed medical history as well as clinical examination, follow-up imaging studies and histological assessment are crucial for a proper diagnosis. Early and accurate differential diagnosis between MO and malignant soft tissue and bone tumours is important to maximize. Cite this article: EFORT Open Rev 2021;6:572-583. DOI: 10.1302/2058-5241.6.210002