M61.112

Clinical Causes: Genetic mutation: Most cases of myositis ossificans progressiva are caused by mutations in the ACVR1 gene, which affects bone growth regulation. Inheritance pattern: The condition is inherited in an autosomal dominant manner, meaning only one copy of the mutated gene is sufficient to cause the disorder. De novo mutations: In some cases, the mutation occurs spontaneously without family history. No known environmental factors directly cause this condition, though trauma or injury may sometimes trigger ossification episodes in affected individuals.

Key Symptoms: Progressive stiffness and limited range of motion in the affected shoulder. Presence of abnormal bony masses or swellings in the shoulder muscles and surrounding tissues. Bony fusions may lead to joint deformities, affecting arm mobility. Pain or tenderness in the affected region during active ossification phases. Potential deformity and abnormal posture of the shoulder over time. In advanced stages, movement may become severely restricted as bones fuse together.

Diagnosis Path: Diagnosis of myositis ossificans progressiva typically involves a combination of clinical evaluation, family history, and imaging studies. Radiographs or X-rays often reveal heterotopic bone formation in the muscles around the shoulder. In some cases, CT scans or MRI may be utilized for detailed imaging. Genetic testing can confirm mutations in the ACVR1 gene, supporting the diagnosis. Early diagnosis is crucial as abnormal bone formation can be mistaken for tumors or other conditions, leading to mismanagement.

Treatment Protocols: Physical therapy: To preserve joint mobility and prevent muscle atrophy, under careful supervision to avoid trauma that could trigger new ossification. Medications: Such as corticosteroids during flare-ups to reduce inflammation and pain, though their long-term benefits are limited. Surgical intervention: Typically avoided due to risks of stimulating further ossification; considered only in specific cases where deformity causes significant functional impairment. Protective measures: To prevent injuries or trauma that may exacerbate the condition. Monitoring and supportive care: Regular imaging and clinical assessments to track disease progression.