6 results
23 - Osteomyelitis
- from Part I - Systems
-
- By Melinda Sharkey, 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 127-130
-
- Chapter
- Export citation
-
Summary
INTRODUCTION
Osteomyelitis is an infectious inflammatory disease of bone, often of bacterial origin. Early diagnosis, antibiotic therapy, and possibly surgical management can control and even eradicate bone infection. Causative organisms vary depending on the portal of entry (direct inoculation versus hematogenous seeding) and the associated health status of the patient.
EPIDEMIOLOGY
Patients with increased susceptibility to osteomyelitis include those with sickle cell anemia, chronic granulomatous disease, diabetes mellitus, and human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Although Staphylococcus aureus is the most common cause of osteomyelitis overall, patients with these chronic medical conditions are especially prone to infection by gram-negative organisms, including Pseudomonas aeruginosa, as well as by fungi and atypical mycobacteria.
CLINICAL FEATURES
The most common route of infection is direct inoculation due to injury. Hematogenous osteomyelitis secondary to bacteremia is usually a single organism infection, whereas direct penetration may involve multiple organisms. S. aureus is the causative organism in most cases of osteomyelitis.
The inflammatory process causes tissue necrosis and destruction of bony structure. Infection also obliterates vascular channels to the periosteum and intramedullary bone, leading to ischemia and areas of necrotic cortical bone, or sequestra. These sequestra are the hallmark of chronic infection, as the devitalized bone cannot be healed by the body's immune response. Surviving periosteum forms new bone, called an involucrum, which encases the dead bone. Draining sinuses form when purulence tracks to the skin surface through irregularities in the involucrum.
26 - Prosthetic Joint Infections
- from Part I - Systems
-
- 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 141-142
-
- Chapter
- Export citation
-
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.
27 - Diabetic Foot Infections
- from Part I - Systems
-
- By Melinda Sharkey, 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 143-146
-
- Chapter
- Export citation
-
Summary
INTRODUCTION
A diabetic foot infection is defined as any inframalleolar infection in a person with diabetes mellitus, and most arise from diabetic foot ulcers. Diabetic foot ulcers are portals of entry for infection in hosts with impaired immunity as well as physiologic limitations to wound healing. Therefore, all diabetic foot ulcers should be treated as chronic wounds that will not heal on their own – intervention is mandatory. Moreover, it is critical that infected diabetic foot ulcers be recognized and treated promptly because they represent the biggest risk factor for nontraumatic amputations in the diabetic population.
EPIDEMIOLOGY
Diabetic foot infections account for the largest number of diabetes–related hospital bed days. In the United States alone, about 82,000 limb amputations are performed annually in those with diabetes, and an amputation in a diabetic patient is associated with a 5-year mortality rate between 39% and 68%.
CLINICAL FEATURES
Purulent secretions, necrotic tissue, and signs of inflammation including pain, redness, warmth, tenderness and induration indicate infection of a diabetic foot ulcer (Figure 27.1, Table 27.1). All patients seen in the acute care setting with diabetic foot ulcers should undergo a basic peripheral vascular exam including palpation of the peripheral pulses and measurement of the ankle brachial index in each leg. An ankle brachial index is calculated by dividing the blood pressure in the calf of the affected foot by the blood pressure in the upper extremity.
25 - Spinal Infections
- from Part I - Systems
-
- 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
-
- Chapter
- Export citation
-
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
-
- 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
-
- Chapter
- Export citation
-
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.
24 - Open Fractures
- from Part I - Systems
-
- By Melinda Sharkey, 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 131-134
-
- Chapter
- Export citation
-
Summary
INTRODUCTION
Open fractures occur when the involved bone and surrounding soft tissues communicate with the outside environment because of a traumatic break in the overlying skin. Many open fractures are a result of high-energy trauma and are associated with severe soft-tissue injury. Lower energy open fractures occur when the skin break is caused by an “inside-out” injury. This occurs when a fractured end of the bone penetrates the overlying skin.
EPIDEMIOLOGY
Fractures represent a major public health problem. The lifetime risk of fracture up to age 65 years is one in two, and every year, 1 in 118 people younger than 65 years of age sustains a fracture. Approximately 2% of all fractures and dislocations are open.
CLINICAL FEATURES
Open fractures can be classified according to the Gustilo classification system (Figures 24.1, 24.2, and 24.3; Table 24.1).
DIFFERENTIAL DIAGNOSIS
Key clinical questions that may help in the diagnosis of open fractures are:
Is an open fracture the source of visible bleeding?
How large is the wound and how severe is the soft-tissue damage?
Are the joints above and below affected?
What is the neurovascular status of the affected limb?
TREATMENT AND PROPHYLAXIS
The rate of infection despite antibiotic administration in type I fractures range from 0% to 2%, in type II fractures from 2% to 10%, and in type III fractures from 10% to 50%.