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26 - Prosthetic Joint Infections
- from Part I - Systems
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- By James M. Mok, Department of Orthopaedic Surgery, University of California, San Francisco School of Medicine, San Francisco General Hospital, San Francisco, CA, Serena S. Hu, Professor of Orthopaedic Surgery, Co-Director, UCSF Spine Care Center, University of California, San Francisco School of Medicine, San Francisco, CA
- Edited by Rachel L. Chin, University of California, San Francisco
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- Book:
- Emergency Management of Infectious Diseases
- Published online:
- 15 December 2009
- Print publication:
- 30 June 2008, pp 141-142
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Summary
INTRODUCTION
Prosthetic joint infection is a feared complication of total joint replacement surgery and occurs as a result of bacterial contamination of the implant surface. It can occur at any point after the initial operation and is characterized by a slow, indolent course that usually results in a delay in diagnosis. Diagnosis and treatment are difficult, and eradication by nonoperative means is rare if not impossible. The consequences of misdiagnosis are substantial and may lead to unnecessary surgery in the case of a false positive. Delays in diagnosis can make control of the infection more difficult and necessitate removal of the prosthesis, which entails prolonged immobilization and delayed reimplantation.
EPIDEMIOLOGY
Approximately 500,000 primary joint arthroplasties are performed every year in the United States. Infection is relatively rare, occurring in 1–2% of primary surgeries, but represents the second leading cause of failure. Treatment for prosthetic joint infection costs an estimated $250 million annually in the United States. The causative organisms are usually Staphylococcus aureus or Staphylococcus epidermidis.
CLINICAL FEATURES
Pain is the most common presenting symptom (Table 26.1). Drainage is the second most common and is strongly suggestive of infection if it is present several weeks postoperatively. Fever is rarely present. The presentation is often subacute, and complaints of pain must be approached with a high degree of suspicion for infection. Most prosthetic joint infections occur as late infections.
25 - Spinal Infections
- from Part I - Systems
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- By James M. Mok, Department of Orthopaedic Surgery, University of California, San Francisco School of Medicine, San Francisco General Hospital, San Francisco, CA, Serena S. Hu, Professor of Orthopaedic Surgery, Co-Director, UCSF Spine Care Center, University of California, San Francisco School of Medicine, San Francisco, CA
- Edited by Rachel L. Chin, University of California, San Francisco
-
- Book:
- Emergency Management of Infectious Diseases
- Published online:
- 15 December 2009
- Print publication:
- 30 June 2008, pp 135-140
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Summary
VERTEBRAL OSTEOMYELITIS
Introduction
Pyogenic infections of the spine are most frequently caused by hematogenous spread. Other possible mechanisms are direct inoculation and local extension from a contiguous infection. Involved structures may include the vertebral body, intervertebral disk, spinal canal, or surrounding soft tissues. Because it is an uncommon disease, diagnosis of vertebral body osteomyelitis is often delayed, and late diagnosis may result in collapse of the vertebral body, kyphosis, and spinal instability that can lead to neurologic compromise.
Epidemiology
Vertebral osteomyelitis usually occurs in men older than 50 years of age, though increasing incidence has been noted in younger patients who are injection drug users. The spine is involved in 2% to 4% of all cases of osteomyelitis with the lumbar region most frequently involved. Gram-positive organisms are responsible for the majority of cases, with Staphylococcus aureus reported as the causative organism in greater than 50% of cases. Vertebral infection by Escherichia coli and Proteus has been associated with preceding urinary tract infection, and infection by Pseudomonas has been reported in injection drug users. Diabetes mellitus or penetrating trauma may increase susceptibility to anaerobic infection. Patients with sickle cell anemia are at risk for Salmonella osteomyelitis. Staphylococcus epidermidis and Streptococcus viridans cause infections characterized by an indolent course.
21 - Adult Septic Arthritis
- from Part I - Systems
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- By James M. Mok, Department of Orthopaedic Surgery, University of California, San Francisco School of Medicine, San Francisco General Hospital, San Francisco, CA, Serena S. Hu, Professor of Orthopaedic Surgery, Co-Director, UCSF Spine Care Center, University of California, San Francisco School of Medicine, San Francisco, CA
- Edited by Rachel L. Chin, University of California, San Francisco
-
- Book:
- Emergency Management of Infectious Diseases
- Published online:
- 15 December 2009
- Print publication:
- 30 June 2008, pp 117-120
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Summary
INTRODUCTION
Septic arthritis is a suppurative bacterial infection of a synovial joint. Most commonly, joint infection occurs through hematogenous seeding of the synovium. Less often, joint infection results from joint aspiration or injection, penetrating trauma, or extension into the joint space from adjacent osteomyelitis. Bacterial septic arthritis is considered a medical emergency because permanent destruction of a joint can occur from the resulting inflammatory response to infection. In particular, bacterial invasion of a joint causes activation of a potent host immune inflammatory response. This results in the production of proteolytic enzymes that destroy the extracellular cartilage matrix of the affected joint.
EPIDEMIOLOGY
Populations at increased risk for septic arthritis include individuals older than 60 years of age, those with osteoarthritis or rheumatoid arthritis, and those on corticosteroids or with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). In particular, individuals with rheumatoid arthritis have a 10-fold greater incidence of septic arthritis than the general population. Individuals with diabetes mellitus or other chronic medical conditions such as renal disease, cirrhosis, granulomatous disease, or malignancy are also at increased risk.
CLINICAL FEATURES
Septic arthritis typically presents with erythema, swelling, tenderness and warmth about the affected joint (Figure 21.1). The patient will display decreased and painful range of motion of the affected joint (Table 21.1). Signs and symptoms of inflammation may be less pronounced in those who are immunosuppressed.
47 - Pediatric Orthopedic Infections
- from Part II - Pediatrics
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- By James M. Mok, Department of Orthopaedic Surgery, University of California, San Francisco School of Medicine, San Francisco General Hospital, San Francisco, CA, Paul D. Choi, Assistant Clinical Professor of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Childrens Hospital Los Angeles, Los Angeles, CA
- Edited by Rachel L. Chin, University of California, San Francisco
-
- Book:
- Emergency Management of Infectious Diseases
- Published online:
- 15 December 2009
- Print publication:
- 30 June 2008, pp 283-290
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Summary
OPEN FRACTURE IN CHILDREN
Introduction
Motor vehicle accidents and falls from height account for the majority of open fractures in children. They differ from open fractures in adults in that children have greater potential for healing due to the thicker periosteum. Infection rates are also lower in children compared to adults. Open fractures in children with closed physes should receive the same treatment as in adults.
Epidemiology
Open fractures have been reported to account for 9% of fractures treated at a pediatric tertiary trauma center. Most studies show a preponderance of boys. The tibia and forearm are the areas most frequently involved.
Clinical Features
The modified Gustilo classification system is used to classify open fractures in children (Table 47.1). The overall rate of infection following open fracture in children is reported as 3%. By type, infection occurs in 2% of type I, 2% of type II, and 8% of type III fractures.
Although community-acquired methicillin-resistant Staphylococcus aureus (MRSA) is of increasing concern, no studies have been published demonstrating superior efficacy of vancomycin, clindamycin, or other antibiotics over cefazolin for open fracture. Indiscriminate use of second-tier agents may lead to increased resistance. Therefore, in the absence of a cephalosporin allergy, cefazolin is recommended as first-line prophylaxis.
Table 47.2 summarizes important clinical features of open fractures in children.