Table of Contents
Introduction
Myositis ossificans is a benign ossifying lesion that is usually self-limiting. It is believed to affect any type of soft tissue, such as tendons, subcutaneous fat, and nerves. It usually occurs in a muscle as a solitary lesion. Ossifying soft-tissue lesions have been inconsistently classified in the past. Myositis ossificans can be categorized primarily into nonhereditary and hereditary types.
The hereditary type is considered a distinctive entity with a different pathophysiology and treatment approach. Myositis ossificans usually has a variable etiology; however, clinical symptoms are often characterized by an ossifying soft-tissue mass. This condition is generally seen in patients between 15 and 35 years who experience pain, swelling, and reduced range of movement post-localized trauma.
Advanced cross-sectional imaging can often be nonspecific and be similar to more disturbing etiologies. Therefore, examining a suspicious soft-tissue mass is usually necessary, and multiple imaging modalities are required for proper diagnosis. If the imaging is indefinite, a biopsy might be suggested for a histologic diagnosis. However, histopathology might differ based on the stage of evolution. The management of myositis ossificans is considered complicated and generally requires multiple approaches for accurate diagnosis and successful treatment.
What Is Myositis Ossificans?
Myositis ossificans is a benign, self-limiting ossifying lesion. It is caused by heterotropic ossification within muscles and soft. It generally occurs in the muscles and soft tissues. Myositis ossificans is commonly seen as a solitary legion in the large muscles of the extremities. If myositis ossificans occurs as a result of trauma, it is termed ‘traumatic myositis occificans’, which is the most common type of myositis occificans.
It accounts for 60 to 75 percent of all cases. The diagnosis becomes easy if the patient has a history of trauma, as the imaging shows clear calcification. However, various cases have been recorded where myositis ossificans occurred in patients without any history of apparent trauma, and malignancy was further suspected. The imaging features of myositis ossificans are often not very helpful in diagnosis as they resemble benign and malignant lesions.
Which Population Is More Prone to Myositis Ossificans?
Myositis ossificans is mostly seen in active, young people, including athletes. It is also more commonly seen in people with paralysis from the waist down (paraplegia), even if the patient has not had an injury that initiated the symptoms.
What Are the Types of Myositis Ossificans?
Myositis ossificans is classified into the following two types:
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Non-hereditary Myositis Ossificans: It is considered the most common type. It is seen after an injury, usually in the thighs or arms. People might also call it myositis ossificans traumatica or myositis ossificans circumscripta as it occurs after a traumatic injury.
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Myositis Ossificans Progressiva: It is an older term used by people that refers to fibrodysplasia ossificans progressiva (FOP). It is a type of myositis ossificans that occurs because of a gene change (mutation).
What Causes Myositis Ossificans?
When a person gets injured, the body starts making new cells immediately to initiate the process of healing. Nonhereditary myositis occificans occurs when the body stops making the right cells during this healing process. The body starts making bone cells instead of making muscle cells (fibroblast). On the other hand, progressive myositis is seen as a result of gene mutation. An individual might inherit this gene from his or her parents, but it can also occur spontaneously.
What Are Myositis Ossificans Symptoms?
The most commonly seen myositis symptoms include a large lump beneath the skin.
The lump usually shows the following characteristics:
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Tender.
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Painful.
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Fast-growing.
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Swollen.
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Warm to the touch.
The lump is seen in the arms or leg muscles in four out of five cases. Individuals with paraplegia are more prone to have lumps around their hips or knees. Your motion might be reduced with the increase in the size of the lump. Further, if the lump is close to a joint movement might be reduced to a greater extent.
How Can We Diagnose Myositis Ossificans?
Your healthcare professional might examine you by touching the bony lump to see if it is warm and tender and further ask you about the symptoms experienced.
The following imaging scans can also be performed to conclude a definite diagnosis:
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Computed tomography (CT) scan.
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Magnetic resonance imaging (MRI).
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Positron emission tomography (PET) scan.
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Ultrasound.
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X-ray.
The healthcare professional can also take a small sample of the tissues to perform a biopsy. A biopsy helps to confirm the presence of myositis ossificans and differentiate it from other conditions with similar symptoms.
How Do We Manage Myositis Ossificans?
For myositis ossificans traumatica, home remedies can be used to manage the symptoms. However, for all types of myositis ossificans, nonsurgical treatments might be initiated, such as:
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Placing ice on the lumps.
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Giving rest to the affected area.
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Gentle stretching.
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Elastic bandages can also be used to reduce swelling.
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Administering nonsteroidal anti-inflammatory drugs (NSAIDs).
The healthcare professional might also advise physical therapy to increase strength, flexibility, and range of movement. The healthcare professional can also recommend surgical removal of the bony growth in severe cases. Generally, surgery is only required if the patient has
severe pain and restricted movement that does not go away with non-surgical treatment.
How to Prevent Myositis Ossificans?
Decreasing the risk of injury can also lower your risk for myositis ossificans. Adequate conditioning, stretching, and proper rest are all essential for injury prevention.
No method guarantees complete prevention of myositis ossificans. However, the risk of myositis ossificans can be reduced by adequately treating the injury, particularly if you experience severe bruising or swelling. The RICE method must be encouraged immediately after injury.
RICE stands for:
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Rest.
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Ice.
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Compression.
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Elevation.
Conclusion
Generally, if myositis ossificans occurs after an injury, it gradually goes away with nonsurgical treatment. The patient can have a limited range of movement or persistent stiffness for months after treatment. To date, there is no complete cure for myositis ossificans progressiva. This is considered a severe condition that leads to symptoms that progress throughout the life of the patient and can lead to a shorter lifespan.
