ICD-10: M61.15

Myositis ossificans progressiva (MOP), classified under ICD-10 code M61.15, is a rare and debilitating condition characterized by the abnormal formation of bone in muscle tissue. This condition primarily affects the thigh but can also involve other muscle groups throughout the body. Below is a detailed clinical description and relevant information regarding this condition.

Clinical Description

Definition

Myositis ossificans progressiva is a genetic disorder that leads to the progressive ossification of skeletal muscle, tendons, and other connective tissues. This abnormal bone formation typically occurs after trauma or injury, although it can also arise spontaneously without any apparent cause.

Symptoms

The symptoms of myositis ossificans progressiva can vary but commonly include:
- Pain and Swelling: Patients often experience localized pain and swelling in the affected area, particularly in the thigh.
- Stiffness and Reduced Mobility: As the condition progresses, stiffness in the muscles can lead to a significant reduction in mobility and range of motion.
- Formation of Bony Masses: Over time, patients may develop palpable bony masses in the affected muscles, which can be detected through physical examination or imaging studies.

Pathophysiology

The underlying mechanism of MOP involves a mutation in the ACVR1 gene, which plays a crucial role in bone and muscle development. This mutation leads to the inappropriate activation of bone-forming cells (osteoblasts) in response to injury or inflammation, resulting in the formation of heterotopic bone—bone that forms in abnormal locations.

Diagnosis

Diagnostic Criteria

Diagnosis of myositis ossificans progressiva typically involves:
- Clinical Evaluation: A thorough medical history and physical examination to assess symptoms and family history.
- Imaging Studies: X-rays, CT scans, or MRIs may be used to visualize the extent of ossification and to differentiate MOP from other conditions that cause similar symptoms, such as traumatic myositis ossificans.
- Genetic Testing: Testing for mutations in the ACVR1 gene can confirm the diagnosis, especially in cases with a family history of the condition.

ICD-10 Code

The specific ICD-10 code for myositis ossificans progressiva affecting the thigh is M61.15. This code is used for billing and coding purposes in healthcare settings to identify the condition accurately.

Treatment

Management Strategies

Currently, there is no cure for myositis ossificans progressiva, and treatment focuses on managing symptoms and preventing complications:
- Pain Management: Nonsteroidal anti-inflammatory drugs (NSAIDs) may be prescribed to alleviate pain and inflammation.
- Physical Therapy: Rehabilitation exercises can help maintain mobility and function, although care must be taken to avoid exacerbating the condition.
- Surgical Intervention: In some cases, surgical removal of the heterotopic bone may be considered, but this is approached with caution due to the risk of recurrence.

Prognosis

The prognosis for individuals with myositis ossificans progressiva varies. While some may experience a relatively stable course, others may face progressive disability due to the accumulation of bone in soft tissues. Regular monitoring and supportive care are essential for managing the condition effectively.

Conclusion

Myositis ossificans progressiva, particularly when affecting the thigh (ICD-10 code M61.15), is a complex condition that requires a multidisciplinary approach for diagnosis and management. Understanding the clinical features, diagnostic criteria, and treatment options is crucial for healthcare providers to support affected individuals effectively. Ongoing research into the genetic basis and potential therapies for MOP holds promise for improving outcomes in the future.

Myositis ossificans progressiva (MOP), classified under ICD-10 code M61.15, is a rare and debilitating condition characterized by the abnormal formation of bone in muscle and connective tissues. This condition primarily affects the thigh but can occur in other areas of the body as well. Below is a detailed overview of the clinical presentation, signs, symptoms, and patient characteristics associated with MOP.

Clinical Presentation

Definition and Pathophysiology

Myositis ossificans progressiva is a genetic disorder caused by mutations in the ACVR1 gene, which plays a crucial role in bone and muscle development. The condition leads to the progressive formation of heterotopic bone, typically following trauma or injury, although it can also occur spontaneously without any apparent cause[1][2].

Age of Onset

MOP usually presents in early childhood, with symptoms often emerging between the ages of 2 and 25 years. However, the onset can vary, and some cases may not be diagnosed until later in life[3].

Signs and Symptoms

Initial Symptoms

• Swelling and Pain: The initial signs often include localized swelling and pain in the affected thigh, which may be mistaken for a muscle strain or bruise[4].
• Limited Range of Motion: Patients may experience a reduced range of motion in the hip joint due to the formation of bone in the surrounding soft tissues[5].

Progressive Symptoms

As the condition progresses, additional symptoms may develop:
- Hard Mass Formation: Patients may notice a firm, bony mass in the thigh, which can be palpated and is often tender to touch[6].
- Stiffness: Increased stiffness in the thigh and hip area can lead to difficulties in walking and performing daily activities[7].
- Deformity: In advanced cases, the abnormal bone growth can lead to deformities in the limb, affecting overall mobility and function[8].

Systemic Symptoms

While MOP primarily affects the musculoskeletal system, some patients may also experience systemic symptoms, including:
- Fatigue: Chronic pain and limited mobility can contribute to overall fatigue and decreased quality of life[9].
- Fever: In some instances, patients may experience low-grade fevers, particularly during acute flare-ups of the condition[10].

Patient Characteristics

Demographics

• Gender: MOP affects both males and females, but some studies suggest a slight male predominance[11].
• Family History: Given its genetic basis, a family history of MOP or related conditions may be present in affected individuals[12].

Comorbidities

Patients with MOP may have other comorbid conditions, particularly those related to mobility and musculoskeletal health. These can include:
- Joint Disorders: Conditions such as osteoarthritis may develop due to altered biomechanics from the abnormal bone growth[13].
- Psychosocial Impact: The chronic nature of the disease can lead to psychological issues, including anxiety and depression, due to the limitations imposed on physical activity and social interactions[14].

Conclusion

Myositis ossificans progressiva is a complex condition with significant implications for affected individuals. Early recognition of symptoms, such as localized pain and swelling in the thigh, is crucial for timely intervention and management. Given the genetic nature of the disorder, understanding patient characteristics and family history can aid in diagnosis and treatment planning. Ongoing research into the pathophysiology of MOP may provide insights into more effective therapies and management strategies in the future.

References

1. ICD-10-AM Disease Code List
2. Prevalence of fibrodysplasia ossificans progressiva (FOP)
3. Myositis Ossificans: Diagnosis, Symptoms and Treatment - Cleveland Clinic
4. ICD-10 code M61.1 | Myositis ossificans progressiva - ICD codes
5. 2025 ICD-10-CM Diagnosis Code M61.15
6. ICD-10-CM Diagnosis Code M61.10
7. Application of the International Classification of Diseases to Myositis Ossificans
8. ICD-10, International Statistical Classification of Diseases
9. 215559Orig1s000 OTHER REVIEW(S) - accessdata.fda.gov
10. Data-Field 41270
11. Data-Field 41202
12. 2025 ICD-10-CM Diagnosis Code M61.151

Myositis ossificans progressiva (MOP) is a rare connective tissue disorder characterized by the abnormal formation of bone in muscles and other soft tissues. The ICD-10 code M61.15 specifically refers to myositis ossificans progressiva affecting the pelvic region and thigh. Here are some alternative names and related terms associated with this condition:

Alternative Names

1. Fibrodysplasia Ossificans Progressiva (FOP): This is the most commonly used alternative name for myositis ossificans progressiva. FOP is the term that emphasizes the progressive nature of the disease and its fibrous tissue origin.
2. Myositis Ossificans: While this term can refer to a broader category of conditions involving bone formation in muscle tissue, it is often used interchangeably with myositis ossificans progressiva, particularly in non-hereditary cases.
3. Progressive Ossifying Myositis: This term highlights the progressive ossification aspect of the condition.

Related Terms

1. Hereditary Myopathy: This term can be used to describe the genetic nature of myositis ossificans progressiva, as it is an inherited disorder.
2. Soft Tissue Ossification: A broader term that encompasses various conditions where bone forms in soft tissues, including but not limited to myositis ossificans progressiva.
3. Ossifying Myositis: This term is sometimes used to describe the condition, focusing on the ossification process within muscle tissue.
4. Congenital Myositis Ossificans: This term may be used in contexts discussing the congenital aspects of the disease, although MOP is typically recognized as a genetic disorder that manifests later in life.

Conclusion

Understanding the alternative names and related terms for ICD-10 code M61.15 is essential for accurate diagnosis, treatment, and communication among healthcare professionals. The terminology can vary, but the underlying condition remains the same, characterized by abnormal bone formation in soft tissues, particularly in the thigh and pelvic regions. If you have further questions or need more specific information, feel free to ask!

Myositis ossificans progressiva (MOP), classified under ICD-10 code M61.15, is a rare and debilitating condition characterized by the abnormal formation of bone in muscle tissue. The diagnosis of MOP, particularly when localized to the thigh, involves a combination of clinical evaluation, imaging studies, and sometimes genetic testing. Below are the key criteria and methods used for diagnosing this condition.

Clinical Criteria

1. History of Symptoms:
   - Patients typically present with a history of progressive pain and swelling in the affected muscle, often following trauma or injury, although MOP can occur spontaneously.
   - Symptoms may include stiffness and decreased range of motion in the affected limb.

2. Physical Examination:
   - A thorough physical examination is essential to assess muscle tenderness, swelling, and any palpable masses that may indicate abnormal bone formation.
   - The examination may also reveal limitations in movement due to the ossification process.

Imaging Studies

1. X-rays:
   - Initial imaging often involves X-rays, which can reveal the presence of heterotopic ossification (abnormal bone growth) in the soft tissues surrounding the muscle.
   - X-rays may show a characteristic pattern of bone formation that progresses over time.

2. MRI (Magnetic Resonance Imaging):
   - MRI is particularly useful for visualizing soft tissue changes and can help differentiate between myositis ossificans and other conditions such as tumors or infections.
   - MRI findings may include areas of edema and the presence of soft tissue masses that later develop into calcified lesions.

3. CT Scans:
   - In some cases, a CT scan may be employed to provide a more detailed view of the bone formation and to assess the extent of ossification.

Genetic Testing

• Genetic Analysis:
• Given that MOP is often associated with mutations in the ACVR1 gene, genetic testing can confirm the diagnosis. This is particularly relevant in cases where the clinical presentation is atypical or when there is a family history of the condition.
• Identification of a pathogenic variant in the ACVR1 gene supports the diagnosis of MOP.

Differential Diagnosis

• It is crucial to differentiate MOP from other conditions that may present similarly, such as:
• Traumatic myositis ossificans: This condition is typically associated with a history of trauma and may resolve with conservative treatment.
• Fibrodysplasia ossificans progressiva (FOP): A more severe form of ossification that can affect multiple areas of the body and is also genetic in nature.

Conclusion

The diagnosis of myositis ossificans progressiva, particularly in the thigh, relies on a combination of clinical assessment, imaging studies, and genetic testing. Early diagnosis is critical for managing symptoms and preventing complications associated with this rare condition. If you suspect MOP, it is advisable to consult a healthcare professional who can conduct the necessary evaluations and provide a comprehensive treatment plan.

Myositis ossificans progressiva (MOP), classified under ICD-10 code M61.15, is a rare and debilitating condition characterized by the abnormal formation of bone in soft tissues, particularly following trauma. This condition can lead to significant mobility issues and pain, necessitating a comprehensive treatment approach. Below, we explore standard treatment strategies for managing MOP, focusing on both pharmacological and non-pharmacological interventions.

Understanding Myositis Ossificans Progressiva

MOP is often associated with a genetic mutation affecting the body's ability to regulate bone growth. The condition typically manifests after an injury, but it can also occur spontaneously. Patients may experience swelling, pain, and stiffness in the affected area, which can severely limit movement and function[1][2].

Standard Treatment Approaches

1. Pharmacological Treatments

• Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): These medications are commonly prescribed to manage pain and inflammation associated with MOP. NSAIDs can help alleviate discomfort and improve the patient's quality of life[3].

• Corticosteroids: In some cases, corticosteroids may be used to reduce inflammation and prevent further ossification. However, their long-term use is generally avoided due to potential side effects[4].

• Bisphosphonates: These drugs, typically used to treat osteoporosis, have shown promise in reducing bone formation in MOP patients. They may help manage the condition by inhibiting the activity of osteoclasts, the cells responsible for bone resorption[5].

2. Physical Therapy

• Rehabilitation Programs: Physical therapy is crucial for maintaining mobility and function. A tailored rehabilitation program can help strengthen surrounding muscles, improve range of motion, and prevent contractures. Therapists may employ gentle stretching and strengthening exercises to enhance flexibility and support[6].

• Hydrotherapy: Water-based exercises can be beneficial, as they reduce the strain on joints while allowing for movement. Hydrotherapy can help improve circulation and promote relaxation, which may alleviate some symptoms of MOP[7].

3. Surgical Interventions

• Surgical Resection: In cases where ossification leads to significant functional impairment, surgical intervention may be considered. The removal of heterotopic bone can restore mobility and relieve pain. However, surgery carries risks, including the potential for recurrence of ossification[8].

• Timing of Surgery: It is crucial to time surgical interventions appropriately. Surgery is generally avoided during the active phase of ossification, as this can lead to further complications. Instead, it is often performed once the condition stabilizes[9].

4. Supportive Care

• Pain Management: In addition to pharmacological treatments, alternative pain management strategies such as acupuncture or transcutaneous electrical nerve stimulation (TENS) may provide relief for some patients[10].

• Assistive Devices: The use of braces, splints, or mobility aids can help patients maintain independence and improve their quality of life. These devices can support affected limbs and reduce the risk of falls[11].

Conclusion

Managing myositis ossificans progressiva requires a multidisciplinary approach tailored to the individual needs of the patient. While pharmacological treatments can help manage symptoms, physical therapy plays a vital role in maintaining mobility. Surgical options may be necessary in severe cases, but careful consideration of timing is essential to minimize complications. Ongoing research into the genetic and molecular mechanisms of MOP may lead to more targeted therapies in the future, offering hope for improved management of this challenging condition.

For patients and caregivers, understanding the condition and exploring all available treatment options is crucial for optimizing outcomes and enhancing quality of life.