Osteomyelitis

Osteomyelitis

Definition

Osteomyelitits is infection and inflammation of the bone and bone marrow

Various Classifications

Acute

Chronic

Pyogenic - Suppurative and Non suppurative

Tuberculous

Aetiology and Incidence

Bacterial : pyogenic organisms : Staphylococcus aureus, Enterobacter species, group A and B streptococcus species, Haemophilus influenzae, Streptococcus species, Salmonella species, anaerobes and Gram-negative bacteria, Pseudomonas aeruginosa, E.Coli

Tuberculous : Mycobacterium tuberculosis : OM may occur secondary to PT

Mycotic infection

In children usually long bones are affected

In adults : the vertebrae and pelvis are affected

Pathogenesis

Mode of infection

3 basic methods

in adults most commonly due to injury exposing the bone to local infection / from areas of contiguous infection (from cellulitis) / seeded Via the bloodstream

Via blood stream - most common

Penetrating trauma including iatrogenic causes such as joint replacements, internal fixation of fractures

In hematogenous spread metaphysis is affected first

Leukocytes surround the infection trying to control spread and Phagocytose the bacteria

They release enzymes that lyse the bone - pus formed - pus spreads into the bone's blood vessels impair the flow - necrosis and dead piece of bone called sequestrum formed. The body forms new bone around the necrotic bone - involucrum - later sclerosis of the bone occurs and deformity is created

The bacteria may become intracellular and escape antibiotics → Chronicity

Investigations

Leucocytosis

X-rays - lytic center with a ring of sclerosis, sequestum, involucrum, raised periosteum

C.T.

MRI

Culture from a bone biopsy, Needle aspirate,surface swabs

Blood culture

Complications of OM

Fracture

Amyloidosis

Endocarditis

Sepsis

Clinical Features

Sudden onset

Chills

High fever

Rapid pulse

General malaise

Local pain - pulsating pain

Extreme tenderness

Chronic OM : continuously discharging sinus

Local swelling, warmth, pain and tenderness

Treatment

General supportive measures like hydration, diet high in vitamins and proteins, correction of anemia

Diseased part immobilized

Warm wet soaks to increse circulation

Pharmacalogic therapy

IV antibiotics initiated against staphylococci - semisynthetic penicillin or cephalosprin, around the clock to sustain high blood level

continued for 3 to 6 weeks. After control orally for 3 months. Oral antibiotics before food

Surgical Management

If nor response to antibiotic therapy infected bone is surgically exposed - purulent and necrotic material removed and irrigated with sterile saline.. Antibiotic-impregnated beads placed in the wound for 2 to 4 weeks

Sequestrectomy

Involucrum is sufficiently removed and saucerization

A closed suction irrigation may be used for 7 to 8 days

External support to prevent fracture

Bone graft later

Nursing Process

Immobilize the part

Pain relieved

Avoidance of weight bearing

Gentle physiotherapy to the joints above and below

Control infection with antibiotics

Wound suction for adequate drainage if needed