Osteomyelitis

the pathogenesis, clinical pre- sentation, diagnosis, and management of pyomyositis in the

Osteomyelitis is one of the more common invasive bacterial infections in children leading to hospitalization and prolonged antibiotic administration. Over the past decade, increasing microbial virulence, diminishing antibiotic susceptibility, and advances in diagnostic molecular microbiology and imaging techniques have led to changes in the clinical management of children with suspected osteomyelitis, which are reviewed in this article.
A bacteriologic diagnosis is more likely with inoculation into blood culture bottles than plating on solid media. As methicillin-resistant Staphylococcus aureus increases in prevalence in the community, empiric antibiotic regimens will increasingly need to be active against methicillin-resistant S aureus.

Mycobacterial Osteomyelitis and Arthritis 819 Michael Gardam and Sue Lim
Osteomyelitis and septic arthritis caused by Mycobacterium tuberculosis are destructive, insidiously progressive, and often diagnosed belatedly by clinicians. Failure to make the diagnosis in a timely fashion may result in severe complications, including loss of joint function, spinal deformity, and paraplegia. Nontuberculous mycobacteria have emerged as an important cause of chronic arthritis and osteomyelitis in recent decades, particularly in immunocompromised individuals. The pathophysiology, clinical presentation, diagnosis, and management of mycobacterial bone and joint infections are reviewed in detail.

Fungal Arthritis and Osteomyelitis 831 Rakhi Kohli and Susan Hadley
Fungal osteoarticular disease may arise as a result of hematogenous dissemination, direct inoculation, or direct extension from a contiguous focus. The most common chief complaint is localized pain. Large, weight-bearing joints, such as the knees, are most commonly affected. Diagnosis is frequently delayed because of slow progression of disease, absence of characteristic laboratory findings, difficulty in culturing the causative organism, and false attribution of fungal pathogens as contaminants. Bone or synovial biopsy or culture is often required to achieve a diagnosis. Successful treatment generally consists of a combination of medical and surgical management.

Gonococcal Arthritis (Disseminated Gonococcal Infection) 853 Peter A. Rice
Neisseria gonorrhoeae was once the most common cause of septic arthritis in the United States, but the prevalence of gonorrhea has diminished in the United States since the onset of the AIDS epidemic. Diagnosing and treating disseminated gonococcal infection today may be troublesome, because gonococcal resistance to fluoroquinolones and other antibiotics is increasing, and many contemporary physicians are unfamiliar with the musculoskeletal manifestations of this complication of gonorrhea. Disseminated gonococcal infection generally causes either a suppurative arthritis resembling septic arthritis caused by other bacteria or a distinct syndrome of tenosynovitis, skin lesions, and polyarthralgias, rather than frank arthritis. Hospitalization is indicated in patients who have suppurative arthritis or when the diagnosis is in doubt. Initial viii treatment with ceftriaxone or an advanced generation cephalosporin is warranted until signs and symptoms have regressed; continuation of treatment can usually be accomplished with a fluoroquinolone.

Reactive Arthritis 863 Danielle Lauren Petersel and Leonard H. Sigal
Reactive arthritis consists of sterile axial or peripheral articular inflammation, enthesitis, and extra-articular manifestations. Most patients are HLA-B27 positive, although determining the B27 status of an individual patient is irrelevant. Reactive arthritis is the result of prior genitourinary or gastrointestinal infection and the immune response to this infection; reactive arthritis does not represent active synovial infection. Diagnosis usually can be made by clinical examination and history. The current standard therapy is nonsteroidal anti-inflammatory drugs and physiotherapy, but molecular biologic treatment may ultimately become the mainstay in recalcitrant and severe reactive arthritis.
Prosthetic Joint Infections 885 Irene G. Sia, Elie F. Berbari, and Adolf W. Karchmer Success in the treatment of infected orthopedic prosthesis requires the best surgical approach in combination with prolonged optimum targeted antimicrobial therapy. In choosing the surgical option, one must consider the duration of the infection, the functionality of the prosthesis, condition of the bone stock and soft tissue, the virulence and antimicrobial susceptibility of the pathogen, the general health and projected longevity of the patient, and the experience of the surgeon. If surgery is not possible, an alternative is long-term oral antimicrobial suppression to maintain a functioning prosthesis. Treatment must be individualized for a specific infection in a specific patient.

Camelia E. Marculescu and Douglas R. Osmon
Infection is a devastating complication of total joint replacement surgery. In the past several decades, the ability to prevent infections after total joint arthroplasty has improved. Antimicrobial prophylaxis, advances in surgical technique, and optimization of patient status all effectively reduce the risk of prosthetic joint infection. In addition to these perioperative measures, the role of antibiotic prophylaxis in the prevention of late arthroplasty infection in patients undergoing dental, urologic, and gastrointestinal procedures is also discussed.

Lyme Arthritis 947 Linden Hu
Arthritis is a common manifestation of untreated Lyme borreliosis, typically presenting as a relapsing arthritis of the knee, and sometimes involving other large and small joints, and periarticular sites. Lyme arthritis follows a relatively indolent course, and joint destruction is unusual. Most patients respond well to a 4-week course of oral antibiotics. Patients with antibiotic-resistant Lyme arthritis usually respond to anti-inflammatory therapy. Even without specific therapy, the symptoms of Lyme arthritis tend to abate with time. This article reviews the current state of understanding about the pathogenesis of Lyme arthritis and recommendations for diagnosis, treatment, and prevention.

Viral Arthritis 963 Leonard H. Calabrese and Stanley J. Naides
The role of viruses in the development of acute and chronic arthritis is complex, because viruses are ubiquitous, and all human beings are occasionally afflicted by viral infections. In general, most viral infections are acute and self-limiting and survive by infecting one susceptible host, then moving on to another. Some viruses establish prolonged latency in the host after acute infection, whereas other agents produce chronic infections following the primary stage. The mechanisms whereby these infections produce arthritis are diverse and still poorly understood, but are clearly influenced by both host and viral factors. This review addresses these and other common forms of viral arthritis, such as that caused by parvovirus B19.
Tropical and Temperate Pyomyositis 981 Lorne N. Small and John J. Ross Pyomyositis is a primary infection of skeletal muscle not arising from contiguous infection, presumably hematogenous in origin, and often, but not invariably, associated with abscess formation. Classically, pyomyositis is an infection of the tropics, occurring in x previously active and healthy young men. Pyomyositis in temperate countries is often regarded as an infection that occurs in hosts who are immunocompromised or otherwise debilitated. However, this distinction may be somewhat artificial, as tropical pyomyositis may be partly related to underlying infection with HIV or parasites, and temperate pyomyositis has been reported in healthy and athletic persons. This article discusses the pathogenesis, clinical presentation, diagnosis, and management of pyomyositis in the tropical and temperate settings.
Suppurative Tenosynovitis and Septic Bursitis 991 Lorne N. Small and John J. Ross Suppurative tenosynovitis and septic bursitis are closed space infections of the musculoskeletal system. Appropriate antibiotics in combination with incision and drainage are generally recommended. Aggressive surgical management is particularly important in tenosynovitis to prevent tendon necrosis. Empiric antibiotic coverage should be directed toward staphylococci and streptococci. Patient characteristics and epidemiologic exposures may provide clues to unusual causative organisms that are occasionally encountered, such as Neisseria gonorrhoeae, Pasteurella multocida, atypical mycobacteria, fungi, and protothecosis.
Musculoskeletal Gene Therapy and its Potential Use in the Treatment of Complicated Musculoskeletal Infection 1007 Wei Shen, Yong Li, and Johnny Huard Antibiotics have greatly improved the outcome of musculoskeletal infections. The treatment of complicated musculoskeletal infections, however, continues to challenge orthopedic surgeons. Many researchers view gene therapy as a new weapon for conquering a variety of musculoskeletal disorders. This article introduces the concepts and strategies of gene therapy, the application of gene therapy in orthopedics, and the reasons why gene therapy could play a key role in the treatment of musculoskeletal infectious diseases.