Traumatic myositis ossificans

Introduction to traumatic ossifying myositis Myositisossificans is a locally reactive disease characterized by fibrosis, cartilage or ossification. Often occurs in soft tissues close to the bone or periosteum. The term ossifying myositis is not appropriate because skeletal muscle is not affected by inflammatory changes. The causes can be divided into traumatic ossifying myositis and progressive ossifying myositis. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific people Mode of infection: non-infectious Complications: elbow joint rigidity

Causes of traumatic ossifying myositis

Causes:

The exact cause is still unclear and is often associated with severe trauma.

Pathogenesis:

Around the elbow joint is one of the predilection sites of myositis ossificans. The exact pathogenesis of this atopic ossification is still unclear. It is often associated with elbow trauma and ossification of elbow joint injury. Myositis is about 3%, 85% of patients with ossifying myositis come from elbow dislocation, and the incidence of elbow fracture combined with dislocation is higher, especially in the small head fracture and elbow dislocation, due to elbow muscle It is also often damaged. Fracture dislocation can cause the periosteum to pick up and tear. The intramuscular hematoma may contain broken periosteum or bone fragments, which release osteoblasts. It may also evolve into fibroblasts during hematomaization. Cells form heterotopic ossification, but it is believed that due to bone trauma, the surrounding bone morphogenetic protein is transferred to damaged soft tissues such as muscles, and the mesenchymal cells around the blood vessels in the soft tissue stimulate the bone forming proteins. Under the evolution of osteoblasts, bone cells, causing heterotopic ossification, rehabilitation of the elbow joint after recovery or scar contraction after burns, forced passive activities and massage, or use of suspension Gravity traction to increase the elbow joint flexion; spinal cord injury combined with quadriplegia and traumatic coma patients in the coma period, passive activities for patients or involuntary convulsions, can also cause elbow trauma and disease, but some ossification Local trauma to myositis is not clear, or very slight, so local lumps can lead to differential diagnosis.

Pathological examination revealed that the mass of the mass and surrounding soft tissue or muscle was clearly defined. The cut surface was white, lustrous, the central part was soft tissue, and the peripheral bone tissue. The mature ossifying myositis mass can be divided into three layers: outer layer, large amount of minerals. Deposition forms the outer shell, and finally becomes a dense plate-like bone. Under the microscope, osteoblasts and osteoclasts can be seen for bone remodeling. In the middle layer, there are a large number of bone-like tissues and abundant osteoblasts, among which there are many slender bones. Cancellous; the core of the inner layer is soft tissue that can be penetrated by X-rays. These soft tissues are active early and have undifferentiated mesenchymal cells. These spindle cells are rich in chromatin, have pleomorphic nuclei, and sometimes mitosis can be seen. However, the cell morphology is normal. Due to these manifestations, it may be misdiagnosed as osteosarcoma. After maturity, the inner layer of hyperactive soft tissue is replaced by adipose tissue.

Traumatic ossifying myositis prevention

To prevent ossifying myositis after elbow joint injury, pay attention to:

1. Early treatment of elbow fracture and dislocation should be no later than 24 hours after injury;

2. The reduction must be carried out under good anesthesia, repeated manual resets, aggravating the injury and increasing the chance of disease;

3. Passive activities and rough massage are strictly prohibited during the rehabilitation period;

4. Radiation therapy may be applied to the fracture and dislocation of the elbow joint and delayed treatment, or ossifying myositis may occur after repeated manipulation. Especially after the removal of ossification block, it is more applicable to prevent postoperative recurrence. After 3 to 4 days after surgery, the total amount was 20 Gy, divided into 10 times. Radiation therapy inhibits the ability of mesenchymal cells to evolve, but radiation therapy can promote early closure of the epiphysis, so the closure of the callus is disabled. Certain drugs, such as tetraphosphate, indomethacin, etc. also have a preventive effect.

Traumatic ossifying myositis complications Complications elbow joint rigidity

Can be combined with elbow joint rigidity.

Traumatic ossifying myositis symptoms Common symptoms Calcified joint swelling joint joint pain, swelling joint swelling and pain

The patient first found a soft tissue mass of the elbow, which was harder and gradually enlarged, accompanied by pain, but it was not painful at night. After about 8 weeks, the mass stopped growing, the pain disappeared, but the elbow joint activity was affected, even when the tumor was immature. Serum alkaline phosphatase can be elevated, and the formation of new bone can vary from several weeks to several months after injury. After 3 to 6 weeks of injury, X-ray films can be seen as ossified, starting with cloud-like annular calcification. The contour is clear, the center is translucent, and the peripheral ossification is obviously dense after maturity. The trabecular bone is inside, and there is often a translucent boundary line between the adjacent bone.

For male adolescents, if there is a history of elbow trauma, swelling after injury is obvious or repeated manipulation, or pain after the passive movement of joints, swelling, often accompanied by low fever, X-ray film sees cloud-like shadows around the joints, months After ossification, joint function is limited, the disease should be considered.

Examination of traumatic ossifying myositis

Serum alkaline phosphatase can be elevated when the mass is immature.

There is no special early X-ray. After 3 to 4 weeks, a cloud-like ossification group is found around the joint. The scope of late ossification is narrowed, the density is increased, and the boundary is clear. CT and MRI examinations can show abnormalities in early cases, and radionuclide scans are injured. Concentration can be found in the last week, and this test has early diagnostic value.

Diagnosis and diagnosis of traumatic ossifying myositis

For ossifying myositis without a history of obvious trauma, it is called pseudo-malignant ossifying fibroma, because from the pathological observation of this benign lesion, it can be seen that the central region proliferates actively, and is easy with osteosarcoma or paracortical flesh. Tumor confusion, misrepresentation of amputation treatment, so it is necessary to fully understand its characteristics, do not do needle aspiration biopsy, should take the entire mass inspection, should be prevented from misdiagnosis.

Differential diagnosis

1. Heterotopic ossification: Heterotopic ossification is often localized. Heterotopic ossification can occur in connective tissues that can form pathological calcification in tissues that are far from the bone and periosteum.

2. Progressive ossifying myositis: It is a congenital disease with repeated inflammation in the fibrous tissue. After each inflammation, ossification occurs in the tendon and muscle fiber interval, and all striated muscles can be affected.

Heterotopic ossification and progressive ossifying myositis are not caused by direct injury and are not controlled by humans.

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