Acute osteomyelitis

Classification and pathogenesis differences

Osteomyelitis is traditionally divided into exogenous and endogenous (hematogenous). There is a fundamental difference in their development.

In the exogenous (e.g., post-traumatic) variant, mechanical damage acts as the triggering factor. Destruction of soft tissues, detachment of the periosteum, and rupture of the bone's own arteries lead to local ischemia. The microbial factor here is secondary: bacteria multiply against the backdrop of already established necrosis. Well-perfused, viable bone has a high resistance to infection.

In the endogenous variant, the process occurs in reverse order. The infectious agent is carried to the bone via the bloodstream from a remote focus (dental caries, furuncle, chronic tonsillitis). Perivascular inflammatory edema develops, compressing intraosseous vessels, while microbial emboli cause their occlusion. As a result, primary infection leads to secondary ischemic necrosis. The preferred localization of this form is the metaepiphyseal zones of tubular bones, which is associated with a rich vascular network. Children and adolescents are predominantly affected.

Clinical presentation

The acute post-traumatic process manifests acutely. Toxic-resorptive fever syndrome develops:

• Sharp increase in temperature (up to 38–39 °C and above).
• Progressive weakness and dyspepsia.
• Blood tests reveal decreased hemoglobin, hypoproteinemia, pronounced leukocytosis, and elevated ESR.

Locally, marked edema, hyperemia, and soft tissue infiltration are observed. Pale granulations, purulent coating, and abundant discharge appear in the wound. Staphylococcus remains the leading pathogen, but today the spectrum is shifting toward gram-negative flora. Of particular danger is the association of Staphylococcus with *Pseudomonas aeruginosa*, which causes severe intoxication and extensive destruction.

Without adequate treatment, the risk of developing sepsis as well as wound exhaustion syndrome (lethargy, earthy complexion, lack of healing tendency) is extremely high.

Bone tissue sequestration

A characteristic manifestation of purulent-necrotic lesions is the formation of bone sequestra—dead fragments detached from the main tissue. Two main types are distinguished:

1. Primary: form directly at the time of injury (freely lying bone fragments deprived of blood supply).
2. Secondary ("true"): form and detach during the development of purulent melting.

Ischemia-affected sequestra become an ideal environment for the multiplication of microflora, sustaining an active inflammatory process.

Principles of treatment in the acute stage

It is impossible to cure osteomyelitis exclusively by conservative methods. The main goal of intervention in the acute stage is the radical suppression of inflammation. The surgeon opens the focus, removes necrotic tissues and freely lying sequestra. The bone cavity is repeatedly washed with antiseptics, often using a pulsating jet, vacuum-assisted closure, and ultrasonic cavitation. The most important rule: after debridement and establishment of active drainage, the wound is not sutured.

Medical support includes massive antibiotic therapy. Drugs are selected based on microbiological culture results. Organotropism is taken into account: aminoglycosides or semisynthetic penicillins are used to achieve high concentrations in soft tissues, while lincomycin possesses a high tropism for bone tissue.

Detoxification therapy, homeostasis correction, and immunocorrection are mandatory. Any internal metal implants in the zone of inflammation are regarded as foreign bodies and must be removed with a transition to an external fixation device.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Stages of development of chronic post-traumatic osteomyelitis
• Primary chronic forms: Brodie's abscess, Garré's sclerosing osteomyelitis, Ollier's albuminous osteomyelitis
• Methods of surgical eradication of the bone cavity (muscle flaps, allografts)
• Radiological diagnosis of non-fistulous forms of osteomyelitis (scintigraphy, MRI)
• The role of local blood flow in bone tissue regeneration and pedicled skin flaps

Other topics in the section "General Questions of Traumatology and Orthopedics"

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