OSTEOMYELITIS and SEPTIC ARTHRITIS..pptx

Osteomyelitis

1. OSTEOMYELITIS Dr.Rabia Jemal (pediatrician )

2. Osteomyelitis Bone infections in children are relatively common Early recognition of osteomyelitis in young patients is of critical importance Appropriate therapy before extensive infection develops will minimize permanent damage. The risk is greatest if the physis (the growth plate of bone) is damaged

3. Etiology

4. Cont…. Bacteria are the most common pathogens in acute skeletal infections In osteomyelitis , Staphylococcus aureus is the most common infecting organism in all age groups, including newborns. Neonate: Staphylococcus aureus Group B streptococcus gram-negative enteric bacilli (Escherichia coli)

5. Cont…. Children: S.aureus H.influenza K.kingae (sporadic or clusters) Group A sterptococcus (<10% of all cases) S. aureus , streptococcus, or Pseudomonas aeruginosa (puncture wounds of the foot) sickle cell anemia: Salmonella species S. aureus pneumococcus

6. penetrating injuries: atypical mycobacteria S. Aureus Pseudomonas Fungal Following disseminated diseases( e.g candidia osteomyelitis in newborn after fungemia ) Primary viral infection of bones is exceedingly rare

7. Epidemiology The median age is approximately 6 yr. are more common in boys than girls; the behavior of boys might predispose them to traumatic event No predilection for race The majority in previously healthy children are of hematogenous origin Minor, closed trauma is a common preceding event in cases of osteomyelitis (30% of the cases)

8. Pathogenesis Microorganisms can be introduced into bone in three ways: Hematogenous delivery Direct inoculation (usually traumatic, but also surgical) Local invasion from a contiguous infection

9. Cont… Ba bacterial deposition in the metaphysis(endothelial cells permit bacterial passage and slugish blood flow in this area) phagocytes migrate to the site Inflammatory exudate ( metaphyseal abscess) protyeolitic enzymes Toxic oxygen radicals cytokines decrease o2 tension and PH Osteolysis Tissue destruction via havarsian system and and volkmans canal exudate spread to the subperiostal space

10. Cont… New borns Thin cortex and loosely applied periosteum are poor barriers to the spread of infection Nutrient metaphyseal capillaries perforate the epiphyseal growth plate The capsule of the diarthrodial joints frequently extends to, or is slightly distal to, the epiphyseal plate So, joint involvement is common in neonates

11. Cont… Older infants and toddlers The cortex becomes thicker and the periosteum slightly more dense Metaphyseal capillaries atrophy as the epiphysis becomes ossified and a distinct physeal plate is formed( begins as early as 8 months and usually complete by 18 months) Thus spread of infection to the joint is unusual in older infants unless the metaphysis is intracapsular , as occurs with the radius and humerus in the elbow and the femur in the hip

12. Cont… Children and adolescents(4-16yrs) The metaphyseal cortex is considerably thicker, with a dense, fibrous periosteum   The infection is more contained and rarely ruptures and spreads to the outer cortical lamellae.

13. Clinical manifestations The earliest signs and symptoms , often subtle and nonspecific, are generally highly dependent on the age of the patient Neonates - pseudoparalysis or pain with movement of the affected extremity .Half of them do not have fever and might not appear ill . Older infants and children- are more likely to have pain, fever, and localizing signs such as edema, erythema,and warmth. Long bones are principaplly involved The femur and tibia constitute almost half of the cases Upper extremities account for one fourth of the cases Flat bones are less commonly affected Usually single bone involved but in neonates two or more bones are involved in half of the cases

14. Diagnosis Laboratory : Blood culture Aspiration for gram stain and culture CBC with differential ESR and CRP are very sensitive in bone infection but non specific May be normal in the first few days of infection Important in assessing response to therapy and identifying complications

15. Radiographic Evaluation : 1 . plain radiograph using soft-tissue technique and compared to the opposite extremity, can show Within 72 hr displacement of the deep muscle planes from the adjacent metaphysis Perioseal reaction 5 – 7days Lytic bone changes 7 - 14days(needs 30-50% bone matrix loss) Flat and irregular bones can take longer

16. Periosteal reaction

17. CT demonstrate osseous and soft-tissue abnormalities ideal for detecting gas in soft tissues MRI the best radiographic imaging technique for the identification of abscesses differentiation between bone and soft-tissue infection provides precise anatomic detail of subperiosteal pus and accumulation of purulent debris 3. Radionuclide studies Valuable if multiple foci bone infection suspected Technetum-99 methylene diphosphonate (99mTc) used Accumulates in areas of increased bone turn over

18. Differential diagnosis Trauma Leukemia(bone/joint pain) Neuroblastoma (bone metastasis) Primary bone tumor( eg . Ewing sarcoma) Chronic recurrent multifocal osteomyelitis (CRMO) and synovitis Psoriasis

19. Treatment Optimal treatment of skeletal infections requires collaborative efforts of pediatricians, orthopedic surgeons, and radiologists Antibiotics choice depends on Age of the patient Underlying medical condition Suspected pathogen and their susceptibility Antibiotiic safety and efficacy and availability

20. Neonates Nafcilline / oxacilline / cloxacilline plus Cefotaxime / ceftriaxone / gentamicine Vancomycine if methicillin -resistant Staphylococcus is suspected Beyound neonatal age nafcillin / cloxacillin / clindamycin / vancomycine plus ceftriaxone /CAF( if H.influenza suspected) Modified based on the pathogen identifed If pathogen not identified Patient improves – antibiotics continued No improvement- reaspiration / biobsy Other diagnosis should be considered

21. Duration of antibiotic therapy is individualized depending on the organism isolated A total of 4–6 wk of therapy may be required Monitor Clinical response Weekly ESR/CRP

22. Surgical Therapy- indications Subperiosteal and soft tissue abscesses and intramedullary purulence Sequestra should be removed Contiguous infectious foci should be debrided adequately osteomyelitis of the femoral head with hip joint involvement

23. Physiotherapy The affected extremity should be kept in extension with sandbags, splints Casts are also indicated when there is a potential for pathologic fracture After 2–3 days, when pain is easing, passive range of motion exercises are started and continued until the child resumes normal activity

24. Prognosis Improvement is rapid when pus drained and appropriate antibiotics therapy is given Failure to improve or worsen by 72hrs require review CRP typically normalizes within 7 days after start of treatment ESR typically rises for 5–7 days, then falls slowly, dropping sharply after 10–14 days Recurrence of disease and development of chronic infection after treatment occur in <10% of patients long-term follow-up is necessary with close attention to range of motion of joints and bone length

25. SEPTIC ARTHRITIS

26. Septic arthritis in infants and children has the potential to damage to the synovium , adjacent cartilage, and bone, and cause permanent disability. Etiology Staphylococcus aureus is now the most common infection in all age groups. Methicillin -resistant S.aureus (>25%) Group A streptococcus and streptococcus pneumoniae historically cause10-20% S. Pneumoniae is most likely in the 1st 2 yr of life Kingella kingae a relatively common etiology in children younger than 5 yr old In sexually active adolescents, gonococcus is a common cause of septic arthritis and tenosynovitis , usually of small joints or as a monoarticular infection of a large joint (knee

27. Group B streptococcus is an important cause of septic arthritis in neonates Candida arthritis can complicate systemic infection in neonates with or without indwelling vascular catheters Primary viral infections of joints are rare, but arthritis accompanies many viral (parvovirus, mumps, rubella live vaccines) syndromes, suggesting an immune-mediated pathogenesis A microbial etiology is confrmed in approximately 65% of cases of septic arthritis

28. Epidemiology is more common in young children. Half of all cases occur by 2 yr of age and three-fourths of all cases occur by 5 yr of age. The majority of infections in otherwise healthy children are of hematogenous origin Immunocompromised patients and those with rheumatologic joint disease are also at increased risk of joint infection.

29. Pathogenesis primarily occurs as a result of hematogenous seeding of the synovial space Less often, by direct inoculation or extension from a contiguous focus The synovial membrane has a rich vascular supply and lacks a basement membrane, Nutrient metaphyseal capillaries perforate the epiphyseal growth plate, permitting spread of infection from the metaphysis to the epiphysis and joint surface

30. CLINICAL MANIFESTATIONS Most septic arthritis are monoarticular . The signs and symptoms of depend on the age of the patient Joints of the lower extremity constitute 75% of all cases of septic arthritis The elbow, wrist, and shoulder joints are involved in approximately 25% of cases, and small joints are uncommonly infected

31. Neonate and young infants Early signs and symptoms may be subtle. It is often associated with adjacent osteomyelitis caused by transphyseal spread of infection Older infants and children fever and pain, with localizing signs such as swelling, erythema , and warmth of the affected joint.

32. Diagnosis Blood culture Joint fluid analysis (, cell counts >50,000-100,000 cells/mm3 , Gram stain and culture) cervical, anal, and throat cultures (If gonococcus is suspected) PCR(most sensitive for kingela kinga ) CBC CRP ESR

33. Radiographic Evaluation Plain Radiographs widening of the joint capsule soft-tissue edema obliteration of normal fat line In hip arthritis medial displacement of the obturator muscle into the pelvis (the obturator sign), lateral displacement or obliteration of the gluteal fat lines elevation of Shenton’s line with a widened arc.

34. Ultrasonography helpful in detecting joint effusion and fluid collection in the sof -tissue and subperiosteal regions CT and MRI For detecting effusion MRI is important to exclude osteomyelitis Radionuclide Imaging more sensitive in providing supportive evidence of the diagnosis of septic arthritis; a scan may be positive within 2 days of the onset of symptoms useful for evaluating the sacroiliac joint.

35. Differential diagnosis For the hip, Toxic synovitis Pyomyositis Legg- calvé - perthes disease Slipped capital femoral epiphysis Psoas abscess Proximal femoral, pelvic, or vertebral osteomyelitis diskitis

36. For the knee, Distal femoral or proximal tibial osteomyelitis , Pauciarticular rheumatoid arthritis Referred pain from the hip . Knee or thigh pain may be referred from the hip Trauma, Cellulitis Pyomyositis Sickle cell disease Hemophilia, Henoch-schönlein purpura

37. When several joints are involved, Serum sickness Collagen vascular disease, Rheumatic fever Henoch-schönlein purpura Inflammatory bowel disease. Reactive arthritis

38. Treatment In neonates nafcillin or oxacillin and a broad-spectrum cephalosporin cefotaxime If MRSA is a concern, vancomycin In older infants and children cefazolin or nafcillin in areas where methicillin resistance is noted in ≥10% Clindamycin and vancomycin In immunocompromised patients, vancomycin and cefazidime or extended-spectrum penicillins and β- lactamase inhibitors with an aminoglycoside dexamethasone for 4 days

39. Surgical Therapy Infection of the hip is generally considered a surgical emergency because of the vulnerability of the blood supply to the head of the femur . For joints other than the hip, daily aspirations of synovial fluid may be required. Generally, 1 or 2 subsequent aspirations sufice . If fluid continues to accumulate afer 4-5 days, arthrotomy or videoassisted arthroscopy is need

40. Prognosis When pus is drained and appropriate antibiotic therapy is given, the improvement in signs and symptoms is rapid. Failure to improve or worsening by 72 hr requires review of the appropriateness of the antibiotic therapy, the need for surgical intervention, and the correctness of the diagnosis. Recurrence of disease and development of chronic infection after treatment occur in <10% of patients

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