What are the causes of myonecrosis (muscle necrosis)?

From the Guidelines

Myonecrosis, or muscle tissue death, is primarily caused by bacterial infections, particularly those involving Clostridium species like Clostridium perfringens, which produce toxins that destroy muscle tissue, as well as non-infectious causes such as compartment syndrome, vascular issues, and certain medications. This condition often develops after traumatic injuries where bacteria enter deep wounds, especially in crush injuries, compound fractures, or deep puncture wounds 1. Non-infectious causes include:

• Compartment syndrome, where increased pressure within a muscle compartment restricts blood flow, leading to tissue death
• Vascular issues such as arterial occlusion, embolism, or severe atherosclerosis can also cause myonecrosis by cutting off blood supply to muscles
• Certain venomous snake bites contain myotoxins that directly damage muscle tissue
• Prolonged pressure on muscles during coma, drug overdose, or after surgery can lead to pressure-induced myonecrosis
• Some medications, particularly statins, can rarely cause drug-induced myonecrosis 1. The most recent and highest quality study, although not directly addressing myonecrosis causes, provides insight into myocardial necrosis, which can be related to myonecrosis in terms of tissue death due to imbalance between oxygen supply and demand 1. Treatment depends on the cause but often includes surgical debridement of dead tissue, antibiotics for infectious cases, and supportive care. Early diagnosis and intervention are crucial to prevent complications like sepsis, limb loss, or death. Hyperbaric oxygen therapy is not recommended due to lack of proven benefit and potential delay in resuscitation and surgical debridement 1.

From the Research

Causes of Myonecrosis

The causes of myonecrosis, also known as muscle necrosis, can be attributed to various factors, including:

• Trauma, such as war wounds or injuries that introduce Clostridium spores into deep tissue 2, 3, 4
• Surgery, particularly orthopaedic surgeries 3, 5
• Malignancy, with 49% of cases associated with malignancies 2
• Immunocompromised conditions, such as neutrophil dysfunction or cyclic/congenital neutropenia 2
• Skin infections or burns 2
• Septic abortions 2
• Injecting drug use, with Clostridium perfringens being a common cause of infection in this population 6
• Vascular insufficiency or other underlying health conditions 5

Risk Factors

Certain risk factors can increase the likelihood of developing myonecrosis, including:

• Age, with older individuals being more susceptible 5
• Gender, with some studies suggesting a higher incidence in males 2
• Underlying medical conditions, such as hemolytic-uremic syndrome or structural bowel ischemia 2
• Trauma to the extremities, which can increase the risk of developing gas gangrene 3

Pathogens

The most common pathogens responsible for myonecrosis are:

• Clostridium perfringens, which is responsible for the majority of clinically relevant infections 2, 4, 6
• Clostridium septicum, which is often associated with a higher mortality rate 2
• Other Clostridium species, such as C. novyi, C. histolyticum, C. fallax, and C. bifermentans 6