Rehabilitation of ossifying myositis Rehabilitation of ossifying myositis Ossifying myositis is also known as heterotopic ossification or ectopic ossification. It is characterized by the formation of new bone within the normal soft tissue near the joint. Its etiology and pathogenesis are not clear. It may be related to a variety of causes, with trauma being the most common one. There are usually 3 theories: ① Hematoma ossification: i.e. fibrosis of the hematoma and gradual formation of cartilage and bone tissue after trauma. ②Fibrous tissue transformation: muscle and connective tissue evolve into bone. ③Osteogenesis of periosteum: simultaneous trauma of muscle and periosteum, periosteum tearing out proliferation of new bone and ossification along the direction of muscle tearing. The exact etiology and pathogenesis are not clear. Because of the abundance of inducible osteoblasts in skeletal muscle and connective tissue, the mesenchymal cells are affected by the inducing factors and proliferate, contributing to the formation of osteogenic proteins or secreted as osteogenic cells, which form ossification in the injured soft tissue such as muscle. The onset of the disease may be related to local repetitive trauma, muscle spasm due to central nervous system trauma, post-prosthetic prosthesis replacement, and neurological and vascular dysfunction. Heterotopic ossification in paraplegic patients is of neurogenic origin and occurs in the front of the hip joint, with an incidence of about 16-30%. Clinical characteristics (a) Classification Heterotopic ossification is divided into 3 types: 1. limited ossifying myositis limited ossifying myositis is also called traumatic ossifying myositis, injured subperiosteal hematoma ossification, etc. Most often seen in direct injury to muscles, such as quadriceps, brachialis, and internal thigh muscles. Restricted ossifying myositis occurs in the elbow and hip joints. The exact pathogenesis is still unclear, but it is usually believed that trauma, fracture or surgery is the main causative factor. Some studies have shown that injury to the joint and surrounding soft tissues caused by violence obviously affects peripheral blood circulation, causing local swelling due to impaired local circulation is an important factor causing ossifying myositis. 2, periosteal ossifying myositis is the formation of new bone adjacent to the periosteum, mostly seen in the spine and femur, such as ossification of the posterior longitudinal ligament. 3, progressive ossifying myositis progressive ossifying myositis is a less common systemic disorder. The etiology is unclear. Most often seen in adolescents. It is characterized by calcification in skeletal muscle and connective tissue, and ectopic ossification in muscle, tendon, and fascia, without necessarily a history of trauma. The calcification often involves the back of the trunk and extremities, affecting the spine and extremities, and has a high disability rate. It is often combined with deformities of the (bunions) toes (fingers), and the course of the disease is progressive. There are different stages of resting phase and apparently rapid progression. If the respiratory muscles are involved, it can cause respiratory failure and death. (C) clinical stage The first stage (i.e. 1 to 2 weeks after injury): local soft tissue inflammatory reaction, swelling continues unabated, local skin flushing, temperature increase, local pressure pain. 2 weeks or less, X-ray often does not show. After a few days, a firm mass is felt in the swollen area, the passive mobility of the joint gradually decreases, and the alkaline phosphatase in the hematoma is high. The second stage (>2 weeks): In the progressive stage of ossification, there is a decrease in local swelling and the soft tissues begin to show stiffness. x-ray can show a deepening of local tissue shadows and a cloudy ossification shadow with indistinct edges. In the stationary phase of ossification, the local soft tissues are stiffer, and the X-ray shows that the ossified tissues have nearly matured, with a reduced ossification range and clear edges. The bone density gradually increases to reach complete ossification. The joint mobility is restricted, and even joint stiffness appears. (IV) Symptoms and signs Post-traumatic heterotopic ossification is most often seen in areas of joint trauma, heavy local surgical trauma, heavy hematoma, or repeated heavy manipulation and massage, and mandatory passive activity. It can occur in any muscle area, mostly in the flexors, quadriceps and internal femoral muscles. If combined with obvious neurological symptoms such as numbness and hypesthesia of the corresponding limbs, or the presence of joint dysfunction, it indicates a more complex symptom than the early stage. The diagnosis of mature stage is mainly based on clinical manifestations and imaging examinations, and attention is paid to differentiate it from other bone tumors such as osteosarcoma to prevent misdiagnosis. Ossifying myositis usually occurs in the part of the backbone adjacent to the long bones, arranged in the direction of the backbone in a laminar pattern, and is more common in the femur, elbow and hip, with a limited mass appearing after injury. It gradually increases in size and becomes hard. It is accompanied by pain and causes limitation of joint mobility. (E) X-ray examination The results initially show an increase in soft tissue density without any structure, and gradually a hair-like dense image within the mass, with periosteal reflection in the adjacent bone, showing high-density cloudy calcification, or a high-density shadow similar to bone structure, with localized new bone image. Mature tissue ossification image is gradually obvious, and there is a transparent band between the mass mechanization and the adjacent bone cortex and periosteum, which is peripheral ossification obviously dense, and within it is bone trabeculae. (vi) Isotope bone scan Positive results can be obtained at the early stage of trauma, showing intra-soft tissue concentrations. (vii) CT examination can show to distinguish its different levels and provide the relationship between the ectopic ossification area and the surrounding tissues. (viii) Diagnosis Based on the history of trauma, there is a hard muscle mass with pain or local pressure, which can lead to a reduced range of motion of the joint. Based on the X-ray film, isotope bone scan or CT findings are of great value for diagnosis. Rehabilitation The timing of surgery for limited ossifying myositis is still controversial and the indications for surgery are not clearly defined. Treatment is not required for osteoid myositis that does not interfere with joint movement. For those with impaired joint movement, surgery can be done after ossification has ceased. For those with mature ossification that interferes with joint function, surgical excision is the only treatment that is considered to resolve severe functional impairment by osteosynthesis tissue and joint release surgery. (I) Indications for surgical treatment Indications include ① obvious joint dysfunction; ② no joint dysfunction but painful symptoms that seriously affect work and life; ③ nerve damage or entrapment symptoms in the forearm or hand; ④ difficult to distinguish from bone tumors, especially malignant tumors. The correct surgical approach should be chosen for surgical resection. (2) Precautions for surgical treatment ① The ossified mass should be completely removed during surgery, and the surrounding thin layer of fibrous scar tissue should be removed at the same time; ② Sharp peeling should be used as much as possible during surgery to reduce contusion to the surrounding tissues. For those with joint dysfunction, intraoperative release should minimize damage to surrounding tissues to prevent re-mechanization; ③ Strict intraoperative hemostasis and routine postoperative placement of negative pressure drainage tube; ④ Before the end of surgery, the surgical area can be flushed with plenty of saline. A large amount of saline flushing can prevent the formation of heterotopic ossification after fracture surgery, and can also reduce the recurrence rate during the surgery of ossifying myositis. Removal of severe local ossification is an effective treatment; ⑤ Timing of surgery is important, as reoperation at an earlier stage will cause more severe ossification and result in surgical failure. The timing of surgery is usually at the stage of ossification maturation and quiescence, i.e. when the X-ray shows uniform and consistent bone formation with clear margins and reduced extent, about 6 months or more is appropriate. Surgical removal of a section of ossified tissue is sufficient to restore joint movement and does not require total removal.