Forms of non-hematogenous osteomyelitis
The posttraumatic process belongs to non-hematogenous osteomyelitides, which develop without the involvement of the bloodstream. Three main pathways of bone infection are distinguished:
- Traumatic: develops upon infection of open injuries (including gunshot wounds).
- Contact (per continuitatem): inflammation spreads to the bone from surrounding soft tissues. Examples: bone whitlow (complication of subcutaneous felon), involvement of the tibia in phlegmonous erysipelas, osteomyelitis of the cranial vault in purulent lysis of the aponeurosis.
- Spread from adjacent organs: destruction of bone tissue due to an adjoining focus of infection (e.g., odontogenic osteomyelitis of the jaw from a tooth or otogenic osteomyelitis of the temporal bone in ear inflammation).
The disease most frequently affects bones that lie close to the skin and are not surrounded by a thick muscular frame.
Etiology and pathogenesis
The leading mechanism of development is the introduction of pyogenic microflora into a contused wound containing bone fragments. The severity and probability of osteomyelitis depend on several key factors:
- Degree of contamination and infection of soft tissues and the fragments themselves.
- Area and depth of the wound canal.
- Presence of foreign bodies.
Main risk factors:
- Delayed primary surgical debridement (PSD) of the wound.
- Use of metal implants (internal osteosynthesis) for immobilization in an infected environment.
Clinical presentation
The process starts with acute purulent inflammation in the fracture zone within the first days after trauma. General symptoms of intoxication (high fever, deterioration of condition) and local signs of phlegmonous inflammation are observed: skin hyperemia, pronounced soft tissue edema, and a significant amount of pus from the wound.
A specific marker of bone involvement is the recurrence of pain directly in the bone fragments or throughout the affected limb.
After opening the phlegmon and ensuring pus outflow, intoxication symptoms quickly subside, and the general condition improves. However, persistent purulent discharge remains. The formation of a fistula communicating with the bone fragments is the main clinical confirmation of the development of posttraumatic osteomyelitis. Subsequently, the process proceeds similarly to hematogenous osteomyelitis: the acute phase transitions into a chronic one with periods of relapses and remissions.
X-ray diagnostics
On radiographs, pathological changes are localized in the fracture zone (which usually remains ununited). The characteristic triad:
- Uzeration (destruction, irregularity) of the ends of bone fragments.
- Formation of small cavities with small lamellar sequestra (fragments of necrotic bone).
- Pronounced osteoporosis against the background of inflammation.
In gunshot osteomyelitis, the picture is supplemented by the presence of foreign bodies (bullets, shot, shrapnel) and two types of sequestra: primary (broken off directly at the moment of injury) and secondary (formed as a result of purulent melting).
Principles of treatment
The basis of surgical treatment is sequestrectomy (removal of sequestra, necrotic fragments, and purulent granulations) combined with excision of fistulas.
Tactics regarding hardware: Hasty removal of implants is not always justified and may worsen the patient's condition. Removal is indicated only in two cases:
- The structure does not provide stable immobilization (e.g., in intramedullary osteosynthesis).
- Extensive bone involvement is observed along the implant.
Therapeutic immobilization: The method of choice is extra-focal compression osteosynthesis (external fixation devices, such as the Ilizarov apparatus). For an ununited fracture, conservative refreshing of the fragment ends and their reposition are performed.
If conservative and basic surgical methods fail to cure a pseudoarthrosis with chronic osteomyelitis, radical tactics are applied: complete elimination of the purulent process with bone resection within healthy tissues and simultaneous bone autotransplantation.
Prevention
To prevent posttraumatic osteomyelitis, three principles must be strictly observed:
- Prevention of secondary infection of open wounds.
- Special thoroughness and timeliness of primary surgical debridement (PSD).
- Strict adherence to indications and contraindications for the use of internal metal osteosynthesis in open fractures.
Class and exam questions
Which clinical sign confirms the transition of the purulent process from the wound to the bone?
A specific sign is the recurrence of pain in the area of bone fragments or throughout the limb against the background of the subsiding primary posttraumatic pain.
Should a metal plate or rod be removed immediately in case of fracture suppuration?
No, hasty removal is not justified. The metal implant is removed only if it does not provide fragment stability or if the bone is destroyed over a large extent along the fixator.
Where do sequestra come from in gunshot osteomyelitis?
In gunshot trauma, sequestra are of two types: primary ones are formed at the moment of the projectile's mechanical impact (bone fragments), and secondary ones form later due to necrosis and purulent inflammation.
What else to study on this topic
- Clinical manifestations of odontogenic and otogenic osteomyelitis
- Technique of sequestrectomy: stages of the operation
- Rules for performing primary surgical debridement (PSD) of open fractures
- Extra-focal compression osteosynthesis (Ilizarov apparatus) in purulent surgery
- Methods of bone autotransplantation in pseudoarthrosis
Master the entire topic in the "General Surgery" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Posttraumatic osteomyelitis" and 3,335 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 70 video lessons on the subject
Other topics from the section "CHAPTER 11. SURGICAL INFECTION (PURULENT-INFLAMMATORY DISEASES)"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.