Oxford Textbook of Trauma and Orthopaedics (2 edn)
Contents
Annotate
Cite
Abstract
Bacteraemia resulting in bone deposition of bacteria
Local bony tenderness, fever, and malaise may not be present initially
WCC may be normal, ESR and CRP normally raised
Plain radiographs normally take 10–12 days to occur
Staphylococcus aureus remains the commonest organism
Immediate antibiotics with surgical drainage of abscess formation.
Summary points
Bacteraemia resulting in bone deposition of bacteria
Local bony tenderness, fever, and malaise may not be present initially
WCC may be normal, ESR and CRP normally raised
Plain radiographs normally take 10–12 days to occur
Staphylococcus aureus remains the commonest organism
Immediate antibiotics with surgical drainage of abscess formation.
Introduction
Osteomyelitis is inflammation of the bone caused by an infecting organism. It may be classified as acute, subacute, or chronic, determined by duration of symptoms.
Acute haematogenous osteomyelitis
Most commonly seen in children (see Chapter 13.1) it has a low incidence in adults following closure of the physis where capillary loops result in a predominance of metaphyseal childhood infection. In adults the immunocompromised host is most susceptible with infection seen most frequently in the elderly or adults with immune deficiency. The spine is the most common site (see Chapter 3.18) but any bone at any site may be involved. Bacteraemia results in deposition of bacteria at the sight of bone involvement but factors such as malnutrition or localized trauma may contribute to the resulting infection.
Clinical presentation
Pain with local bony tenderness but fever and malaise may not be present initially. Local swelling is associated with periosteal or soft tissue abscess formation. Associated erythema and warmth are cardinal signs of infection. There may be loss of local joint function and with extreme pain on swollen joint move-ment septic arthritis must be excluded, the infection ext-ending through the bone to directly involve the joint. In long-standing cases, cortical bone destruction can lead to pathological fracture.
Investigations
Blood tests: the white cell count may be normal. The erythrocyte sedimentation rate and C-reactive protein are usually raised
Radiological: plain radiographs in the acute phase show no changes, Periosteal changes or cortical destruction normally take 10–12 days to occur
Technetium-99m bone scans will demonstrate increased uptake
Magnetic resonance imaging will show perisoteal reaction, soft tissue involvement, and bone marrow inflammation.
Microbiology
The causative organism can be identified by blood cultures in approximately 50% of patients. Bone aspiration or pus specimens may be taken at surgical drainage
Staphylococcus aureus remains the commonest causative organism in adult osteomyelitis
Pseudomonas is often seen in intravenous drug abusers
Salmonella osteomyelitis is reported in patients with sickle cell disease, most often affecting the diaphysis. This, however, is still less common than Staphylococcus aureus.
Treatment (Box 11.4.1)
Systemic treatment should include limb splintage, analgesia, and fluid resuscitation
Antibiotics: intravenous administration of broad spectrum antibiotics are commenced immediately after culture specimens taken (blood and/or direct bone aspiration). Change is then directed by sensitivity and specificity after culture. Continuation is generally for 6 weeks although this is controversial. Debate also is undecided over timing of change from intravenous to oral route
Surgical drainage is indicated when significant subperiosteal or soft tissue abscesses are present. Drainage is usually via an incision centered over point of maximum tenderness. Bone drilling may be required both proximal and distal to the involved area to ensure complete drainage
Surgical exploration may also be indicated if a patient fails to improve symptomatically after 24–48h of antibiotic treatment
Packing of the wound with a planned second look, further debridement, and wound closure may be considered. The use of antibiotic beads or collagen sponge is not usually required.
An appropriate antibiotic, effective prior to pus formation
Avascular tissues and abscesses require surgical removal
After successful removal, antibiotics should prevent recurrence and primary wound closure can be undertaken
Surgery should not damage further already ischaemic bone and soft tissue
Antibiotics should be continued after surgery.
Outcome
Infection can recur several years following apparent successful primary treatment; most occur within 1 year, however. Therefore patients should be consented for recurrence and possible need for further treatment.
Subacute haematogenous osteomyelitis
This has a more insidious onset with few symptoms. Pain may be present for some weeks with minimal systemic symptoms or signs. Often no temperature or malaise is present.
Blood tests are usually normal; the erythrocyte sedimentation rate may be slightly raised in 50% of cases. Radiographs and bone scans are positive and a classification based on radiographic changes was proposed by Gledhill and modified further by Roberts and colleagues (Box 11.4.2).
Gledhill (1973):
I: solitary localized zone of radiolucency surrounded by reactive new bone formation
II: metaphyseal radiolucencies with cortical erosion
III: cortical hyperostosis in diaphysis; no onion skinning
IV: subperiosteal new bone and onion skin layering
Roberts et al. (1982):
V: central radiolucency in epiphysis
VI: destructive process involving vertebral body.
The lack of symptoms is thought to be due to increased host resistance. The differential diagnosis must include exclusion of a primary bone tumour and biopsy and curettage are advised. An organism is identified in only 60% of cases and those negative cases with a high index of diagnostic suspicion should be treated empirically with antibiotics for 6 weeks.
Further reading
| Month: | Total Views: |
|---|---|
| October 2022 | 2 |
| November 2022 | 5 |
| December 2022 | 2 |
| January 2023 | 2 |
| February 2023 | 4 |
| March 2023 | 4 |
| April 2023 | 2 |
| May 2023 | 1 |
| June 2023 | 3 |
| July 2023 | 2 |
| August 2023 | 2 |
| September 2023 | 2 |
| October 2023 | 2 |
| November 2023 | 1 |
| December 2023 | 2 |
| January 2024 | 2 |
| February 2024 | 1 |
| March 2024 | 2 |
| April 2024 | 3 |
| May 2024 | 2 |
| June 2024 | 2 |
| July 2024 | 1 |
| August 2024 | 1 |
| December 2024 | 2 |
