Osteomyelitis and Septic arthritis 8 2551 Complication n

Osteomyelitis and Septic arthritis ��. �� ��������� 8������� 2551

Complication n Sepsis, Toxic shock n disability and deformity

Classification n Age group q q q n Neonate Childhood Adolescent Duration of symptom q q q Acute Sub-acute Chronic

Classification n Route of infection q q q n Hematogenous system** Direct inoculation : Open Fx, operation, skin puncture Soft tissue infection Causative organisms q q Pyogenic organisms** granulomatous

Natural history and Pathogenesis of Acute hematogenous osteomyelitis n Almost at “metaphysis” lower extremities > upper extremities 5 ����������� distal femur ��� proximal tibia q metaphysis (no phagocytosis cell) ≠ diaphysis (diaphysis = reticuloendothelial tissue + phagocytosis cells) q

Source of infection n Blood circulation : q n infection in Oral, Throat, Ear, Gastrointestinal tract, Urinary tract, Skin and soft tissue Trauma (30 -50%) ������ q Minor trauma Caution : in infant < 18 month ������� septic arthritis ������� Osteomyelitis q

Pathogenesis Source of Infection Blood stream Metaphysis Venous stasis Bacterial colonization

Inflammation: acute osteomyelitis n First 24 hours Vascular congestion n Polymorphonuclear leukocyte infiltration n Exudation n

Inflammation: acute osteomyelitis n 2 -3 day No treat with antibiotic n Intraosseus pressure intense pain intravascular thrombosis ischemia ��������

Suppuration v v 4 -5 days Pus formation Subperiosteal abscess via Volkmann canals Pus spreading v v epiphysis joint medullary cavity soft tissue

Necrosis n n Bone death by the end of a week Bone destruction ← toxin ← ischemia Epiphyseal plate injury Sequestrum formation q q small removed by macrophage, osteoclast. large remained

New bone formation n By the end of 2 nd week (10 – 14 days) Involucrum (new bone formation from deep layer of periosteum ) surround infected tissue. If infection persist- pus discharge through sinus to skin surface Chronic osteomyelitis

joint capsule of 4 metaphysis cause of osteomyelitis n n Femoral head and neck ( hip ( Humeral head ( shoulder ( lateral side of distal tibia ( ankle joint( radial head and neck ( elbow joint(

Signs and Symptoms in infant Drowsy Ø Irritable Ø Fails to thrive Ø history of birth difficulties Ø History of umbilical artery catheterization Ø Metaphyseal tenderness and resistance to joint movement Ø

Signs and Symptoms in child Ø Severe pain Ø Malaise Ø Fever Ø Toxemia Ø History of recent infection Ø Local inflammation Ø Lymphadenopathy pus escape from bone

Septic Arthritis

Natural History and Pathogenesis of Septic arthritis n Septic arthritis �������������� single joint pain ���� neonate ������ 1 ��� q % 50 - 35����� HIP q 20 – 25 % ����� Knee q ������ shoulder , ankle , elbow etc

Source of infection n Same as hematogenous osteomyelitis : Blood circulation q Post operation q Skin and tissue infection etc. q

Complication n Synovial fluid = good culture media n Within 8 hr. loss of glycosaminoglycan Wear and tear synovitis Cartilage destruction in 5 day

Signs and symptoms in newborn n Clinical of septicemia : fever (36 - 74 %) irritable, refuses to feed, rapid pulse n Joint swelling n Tenderness and resistance to movement of the joint n Look for umbilical infection

Signs and symptoms in children acute pain in single joint ���� : hip. n Pseudoparesis. n Swelling and inflammation of the joint. n Child looks ill. n Limit movement of the joint. n Look for a source of infection : toe, boil, otitis media n

Diff. diagnosis Toxic synovitis ������� direction �������� Rolling test ��������� flex ����� , extend ���� rotate ���������� n Toxic synovitis ( transient synovitis ) ���������� Rolling test ����������� internal ratation n Juvenile rheumatoid arthritis ������ ������������������� look sick n

Investigation after admit CBC n U/A n ESR n aspirate ���� bone ( metaphysis ) n Gram stain of synovial fluid n C/S n Plain film n

Physis destruction with avascular necrosis of femoral head

Investigation : Plain film ��������� 10 ��� Ø ���� periosteal new bone formation rarefaction, area of lytic and sclerotic lesion, sequestrum and involucrum. Ø ����������������� ��� X-ray Ø

Investigation: MRI ����� : infection ��� spine ����������� tumor MRI n �� Osteomyelitis n ��������� marrow signal intensity �� T 1 wieghted images q ���������� marrow signal intensity �� T 2 weighted images ����� marrow fat ������� inflamatory cells ��� edema q

Investigation: CT scan n ���� extent ��� bone destruction �������� exposure ���� Osteomyelitis ��� spine ���� pelvis

Investigation : Bone Scan Ø ���������� locate lesion �� early stage ������� (foci) Ø 99 m TC-HDP n ���� 2 phases q q - sensitive - not specific vascular phase warm (hot) uptake ��������� pool ������ swelling & inflamation ��������� osseous phase ���� warm (hot) uptake ����� bone ����� lesion ��������� bone scan ������

Investigation : Aspiration confirm diagnosis n �������� Antibiotic n smear for cell and organism n culture and sensitivity test n

Synovial fluid cells count analysis Early case : WBC 25, 000 – 50, 000 / μL n Late case : WBC count >50000 / μL (Juvenile rheumatoid arthritis ������ ) n > 3 day �� PUS ��������� debris tissue, fibrin exudate ��� enzymes ���� cartilage ��� n +��� close suction drainage���

Empirical treatment Condition Organism Agent Sepsis Neonate Organism Agent Staph A, Group A and B strep, coliforms Cloxacillin + gentamicin H. flu, pneumococcus, meningococcus Cetriaxone or cefotaxime Group B strep, staph, coliforms Cloxacillin + gentamicin Infant H flu, staph A, group A and B strep Cefotaxime Child Staph. aureus Cloxacillin Neonate Group B strep, staph A, coliforms Cloxacillin + gentamicin Infant / Child Staph. aureus Cloxacillin Through shoes Pseudomonas Cetaxidime + gentamicin Barefoot Staph. aureus Cloxacillin Infant Septic Arthritis Neonate Osteomyelitis Nail puncture Discitis

Antibiotic treatment Age Pathogen Drugs 1. Healthy Neonate (< 1 mo) -Staphylococcal Gr. B infection - cloxcillin 50 mg/kg/day 2. Infant and children -Staph. Aureus -Gram neg. infection -Haemophilus infection -2 nd generation Cephalosporins or Amoxycillin with clavulanic acid 3. Adolescent (11 – 15 -Staph. Aureus years) -Neisseria gonorrhea 150 – 200 mg/kg/day IV divide q 4 – 6 hr. max 12 gm. /day 4. Sickle-cell patient - Co-trimoxazole - Amoxycillin with clavulanic acid -Salmonella infection

Antibiotic treatment Cefotaxime 100 – 200 mg/kg/day IV ���� 6– 8 ������� (Neonate �� dose ���� 50 mg/kg/day ����� 8 – 12 ������� ) ���� Ceftriaxone 50 – 100 mg/kg/day ����� 12 ������������� H. influenza , Salmonella, Neiserria gonorrhea n ������ Cefazolin 100 – 150 mg/kg/day ����� 8 ������� Cloxacillin ������� penicillin ������ Clindamycin 30 – 40 mg/kg/day n

Criteria Switch antibiotic IV to Oral Compliance of patient n Clinical sign and symptom: Fever <38 C (>72 hr. ) , reduce pain , n CRP lower to normal n Switch to High dose oral antibiotic : Cloxacillin , cefazolin Cloxacillin , Cephalexin 100 – 150 mg/kg/d divided qid maximum dosage : 4 g/d n

Clinical improvement Acute osteomyelitis Septic arthritis 7 day 2 -3 day Fever improvement Early treatment (<48 hr) Delay treatment 2 -3 weeks Total time treatment 3 -6 weeks 2 -4 weeks

Subacute osteomyelitis ����������������� n �������������������� n ESR ����� CRP������ n Hemoculture ������ Plain n film ������ lytic lesion with or without sclerotic border ���� metaphysis n

Chronic osteomyelitis n n ����� delay diagnosis and treatment ��� Acute osteomyelitis ������� sequestrum, involucrum ��� chronic sinus drainage ����� sequestrum ������� plain film ������ debridement, sequestrectomy, saucerization n ����������� IV pre OP ��� post OP ������ 7 ��������� high dose ���� 6 ������� ESR < 25 ������� remove sequestrum ���� dead bone ����� blood supply ����� phagocytic cells ����������� n

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