Osteomyelitis Osteomyelitis is infection in the bone. Infants,children,and adults. In children >>at the ends of the long bones of the arms and legs, affecting the hips, knees, shoulders, and wrists. In adults >>bones of the spine (vertebrae) or in the pelvis.
Risk factors Diabetes Hemodialysis Injected drug use Poor blood supply Recent trauma Surgery The elderly
Symptoms Bone pain Fever malaise Local swelling, redness, and warmth Other symptoms may occur : Chills Excessive sweating Low back pain Swelling of the ankles, feet, and legs
Acute hematogenous osteomyelitis l mostly children l history of trauma l Long bone >> most common l In children >> metaphysis l Most vascular part l Blood flow slow l Most part subject to trauma l In adult >> epiphysis
The organisms l Gram +ve l Staphylococus aureus (80-90%) l Strep. pyogen l Strep. pneumonie l Gram -ve l Haemophilus influnzae (50% < 4 y) l E.coli l Pseudomonas auroginosa, l Proteus mirabilis
Source Of Infection l Infected umbilical cord in infants l Infection ( respiratory, intestinal, urinary, oral, boils, tonsilitis, skin abrasions)>> bacteramia l Traumatic implantation
Pathology l Minor trauma to adjacent joint, suppuration l starts at metaphysis l Subperiosteal abscess l Bone necrosis l new bone formation“ ivolucrum” l Channels through soft tissue “sinuses” l Sinuses appear thick-walled holes “cloacae” l Death of bony segment “sequestrum”
Complication Pathological fracture. Direct spread of infection arthritis,myositis Blood spread septicaemia, pyaemia Chronic suppurrative osteomyelitis.
Acute non- hematogenous osteomyelitis Causes – Infection of fractured bone – Infection of skull bone by direct spread Pathologhy – Resemble hematogenous except no Subperiosteal abscess
Subacute Osteomyelitis Brodie's abscess, a chronic abscess of bone surrounded by dense fibrous tissue and sclerotic bone. The lesion usually is within the metaphysis, but can occur anywhere.
Chronic OM May following acute OM. Sclerosing osteomyelytitis of Garre – a chronic form involving the long bones, especially the tibia and femur, marked by a diffuse inflammatory reaction, increased density and spindle-shaped sclerotic thickening of the cortex, and an absence of suppuration. – Develop in the jaw and characterized by extensive new bone formation.
Elderly Diabetes mellitus Rheumatoid arthritis Prosthetic joint Recent joint surgery Skin infection IV drug abusers
Blood borne infection (the most common route) Direct inoculation – entry via penetrating injury – entry via iatrogenic means Contiguous spread from osteomyelitis or soft tissue abscess. – In adults, the arteriolar anastomosis between the epiphysis and the synovium permits the spread of osteomyelitis into the joint space.
fever swelling warmth inability to move the limb with the infected joint severe pain in the affected joint, especially with movement
Caused by bacteria Virtually every bacterial organism has been reported to cause septic arthritis. Bacterial species causing septic arthritis vary with the age of the patient. – The most common species overall is S. aureus – Neisseria gonorrhea is the most common cause in sexually active adults – H. infleunza occasionally implicated in preschool children.
The major consequence of bacterial invasion is damage to articular cartilage. – Organism's pathological properties, such as the chondrocyte proteases of S aureus. – Host's PMNL response. cytokines and other inflammatory products hydrolysis of essential collagen and proteoglycans.
S. aureus The most common cause of septic arthritis: – adults – children older than 2 years. – 80% of infected joints affected by rheumatoid arthritis – early prosthetic joint infections (PJI) – Polyarticular arthritis Mortality rate approaches 50%.
CNS staphylococci delayed PJI infections Streptococcal species the second most common cause – Streptococcus viridans – Streptococcus pneumoniae – group B streptococci
N.gonorrhoeae Gonococcal arthritis the most common pathogen (75% of cases) among younger sexually active individuals Pathogenesis is ultimately a consequence of disseminated gonococcal infection (DGI).
Arthritis-dermatitis syndrome includes the classic triad of – dermatitis – tenosynovitis – migratory polyarthritis. Unlike in S. aureus septic arthritis, joint destruction is rare low mortality rate.
H.infleunza occasionally implicated in preschool children. Escherichia coli in the elderly, IV drug users and the seriously ill Salmonella spp. Pseudomonas aeruginosa or Serratia species cause infection of the sternoclavicular and sacroiliac joints almost exclusively in persons who abuse intravenous drugs.
Aeromonas Persons with leukemia are predisposed. Pasteurella multocida, Capnocytophaga species (dog and cat bites) Brucella spp. lumbosacral spine involvement.
Acid fast Mycobacteria are a rare cause of septic arthritis. Anaerobes usually a consequence of trauma or abdominal infection. 5% of cases Fusobacterium nucleatum Eikenella corrodens Streptococcal species (human bites)
Viral infections may cause: – direct invasion rubella virus – production of antigen/antibody complexes. hepatitis B, parvovirus B19 lymphocytic choriomeningitis viruses
Hepatitis viruses Hepatitis A Hepatitis B – Onset in the prodromic stage. – Usually resolves as jaundice develops – Chronic arthritis possible in patients with chronic hepatitis B infection Hepatitis C
Parvovirus B19 Occurs in adults esp. women Mainly involves the small joints of the hands and feet bilaterally. Rubella (natural infection and vaccine related) – Onset possible before, during, or after the appearance of the rash – Mild, short lived and without major impairment of joint function.
HIV 2 types occur, both with noninflammatory sterile joint fluid Mumps Occurs in adult men 2 weeks after the presentation of parotitis Mild, short lived and without impairment of joint function.
Candida albicans Sporothrix schenckii Coccidioides immitis, Histoplasma species, and Blastomyces species
Spirochete Borrelia burgdorferi. – Lyme arthritis – Develops in 60%-80% of untreated patients. – The dominant feature of late disease (stage 3) – may produce nonsuppurative joint infection – Borrelia antigens cross react with proteins in the joints
Acute inflammation of the joints that follows infection with various bacteria, but the joints are sterile. i.e. inflammation is a “reaction” to the presence of bacterial antigen elsewhere in the body. Usually oligoarticular and asymmetric. Bacterial infection precedes the arthritis by a few weeks.
Antibiotics have no effect Anti-inflammatory agents are typically used. Increased risk in persons with HLA-B27 locus Thought to be immunologically mediated. Reiter’s syndrome icludes reactive arthritis, but affects multiple organs.
The syndrome is characterized by the triad of: – Arthritis – Conjunctivitis – Urethritis Infection by one of the following predisposes to the disease: – Salmonella spp. – Shigella spp. – Campylobacter spp. – Yersinia spp – Chlamydia trachomatis
Septic arthritis Joint fluid aspiration – Microscopy Absence of crystals to rule out gout & pseudogout – Culture