Bone and Joint Infections Case Presentations Pediatric MSK Bootcamp Sept 29, 2019 American Academy of Pediatrics/ Penn State

Transcription

1 Bone and Joint Infections Case Presentations Pediatric MSK Bootcamp Sept 29, 2019 American Academy of Pediatrics/ Penn State Douglas Armstrong MD Penn State College of Medicine

2 Disclosures I have no relevant financial relationships with the manufacturers of any commercial products and/or providers of commercial services discussed in this CME activity. I do not intend to discuss an unapproved/investigativ e use of a commercial product/device in my presentation.

3 Learning Objectives Describe the Kocher/Caird criteria for differentiating a septic hip from toxic synovitis Describe the clinical presentation of discitis Identify the complications associated with MRSA osteomyelitis List the manifestations of Lyme disease

4 Outline Septic hip Discitis Distal fibula osteo--mrsa Lyme knee CMFO Tibia osteo Pre-patellar bursitis Other

5 Case # 1 18 mo infant with irritable right hip 18 mo old boy presents with fever 101, not walking 1 day, irritable right hip, no trauma SVD 7lb W 12 mo Meds none Allergies none Immunizations UTD

6 Exam Right hip flexed, abducted, externally rotated Pain with hip motion No rash No other joint or bone tenderness Labs WBC 17,000 ESR 57 CRP 3.9 Blood culture sent

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9 5 cc yellow fluid Negative string sign Cell count 78,000 Gm Stain WBC no organisms seen Culture pending

10 Pediatric Septic Hip Pearls Epidemiology Incidence Age Peaks in the first few years of life 50% of cases < 2 years of age Hip joint involved in 35% of all cases of pediatric septic arthritis Risk factors for neonatal septic arthritis Prematurity Cesarean section

11 Pathophysiology Routes of inoculation 1. Hematogenous invasion of the synovium from a distant site Common in neonates who have transphyseal vessels that allow direct blood flow into the joint 2. Extension from metaphyseal osteomyelitis Joints with intra-articular metaphysis include Hip Shoulder Elbow Ankle 3. Direct inoculation from trauma or surgery

12 Pathogenesis Acute inflammatory response involving synovial tissue Release of proteolytic enzymes from synovial and inflammatory cells in response Degradation of articular cartilage begins May cause articular surface damage within 8 hours (JOR 2011) Cytokine secretion by chondrocytes Increased joint pressure may cause femoral head osteonecrosis if not relieved promptly

13 Laboratory work up Blood culture positive 30-50% WBC, ESR and CRP elevated Radiographs May be normal, especially in early stages of disease Often see widening of the joint space, subluxation, or dislocation In infants, prior to ossification of the femoral head, widening of joint space can be seen by lateral displacement of the proximal femur May see bone involvement with associated osteomyelitis Ultrasound MRI Helpful to identify effusion 100% sensitive for joint effusion Capsule-to-bone distance that is >2 mm wider than the distance on the contralateral side Guide to aspiration Difficult to obtain emergently Joint effusion, abscess, adjacent osseous involvement Helpful is suspect MRSA

14 Joint Aspiration WBC count WBC > 50,000/mm3 with predominance of neutrophils (> 75%) suggestive of infection Joint Fluid Gram stain WBC < 50,000 in 17% of patients (JBJS 2015) WBC can be elevated in JIA/Lyme arthritis Positive in 50% Joint Fluid Cultures Positive in 75% Low protein, low glucose, high lactate levels compared to serum indicative of infection

15 Kocher et al (JBJS 1999) Review of pediatric patients with septic arthritis 4 independent multivariate clinical predictors were identified to differentiate between septic arthritis and transient synovitis WBC > 12,000 cells/µl Predictors: 0/4 = 0.2% 1/4 = 3% 2/4 = 40% 3/4 = 93% 4/4 = 99% Inability to bear weight Fever > 38.5 C ESR > 40 mm/h

16 Caird et al (JBJS 2006) Level I prospective study of 53 children who underwent hip aspiration for suspected septic arthritis Kocher criteria + CRP > 2.0 mg/dl Patients with 5 predictive factors had a 98% chance of having septic arthritis, those with 4 factors had a 93% chance, and those with 3 factors had an 83% chance Best predictor of septic arthritis Fever (oral temp > 38.5 C) Followed by an elevated CRP CRP of > 2.0 mg/dl was a strong independent risk factor and a valuable tool for assessing and diagnosing children suspected of having septic arthritis of the hip

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18 Treatment Non-operative Adolescent Neisseria gonorrhoeae infection Can be treated with high dose PCN alone, usually does not require surgical debridement Operative Emergent surgical I&D Create capsular window to ensure continued drainage Leave drain in place 24 hrs Follow with IV antibiotics targeting pathogens based on age and medical comorbidities Convert to PO antibiotics once the clinical picture improves, sensitivities are obtained, CRP nl Duration of antibiotic therapy is generally 3-4 weeks: ESR nl

19 Complications Femoral head destruction Deformity Physeal damage leads to late angular deformity and LLD Coxa vara, coxa breva Joint contracture Dislocation Growth disturbance Gait abnormalities Osteonecrosis Post-infectious arthritis

20 Next Case

21 Case # 2 3 yo girl back pain difficulty walking Afebrile No trauma Difficulty walking Back pain Unable to flex the spine Loss of lumbar lordosis WBC 9K, ESR 39, CRP 2.1

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25 DISCITIS: Pearls Bacterial infection Hematogenous spread Channels through end plates--nutrient arterioles vertebral body and end plates Blood cultures helpful MRI very helpful Disc anatomy Peds: blood vessels extend from cartilage end plate to nucleus pulposus Adults: blood vessels extend only to annulus

26 Discitis Males < 6 years old Lumbar spine Staph Aureus, Tb, Salmonella sickle cell Common presentation refusal to walk, fever, pain back or abdomen Complications Fusion Back pain Biopsy + - indicated case by case decision RX: antibiotic + brace Surgery if epidural abscess or neurologic change

27 Brown R JBJS 83B 2001 Spencer S JPOB 2012 Principi N Int J Mol Sci 2016

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29 Case #3 8 yo female 1 week limp, 24 hours refusal to bear weight Temp 102 Tender and swollen at left distal fibula WBC 15K ESR 86 CRP 7.1 Blood culture sent

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32 Joint aspiration: 7 k cells no orgs Bone aspiration: sub-periosteal abscess--gross pus culture sent

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34 MRSA

35 Treatment I and D, drain 7d IV Vancomycin CRP at day 7: 1.0 (8.1) Changed to oral Clindamycin and Rifampin for 3 weeks ESR at 4 weeks: 18 Stopped antibiotics

36 3 mo later playing soccer

37 Osteomyelitis Pearls 1 in 5000 children in USA 1 in 1000 neonates in NICU 6 % have long term sequelae Song et al JAAOS 2001

38 Acute Osteomyelitis Pathogenesis Local trauma Hematogenous spread Bacteremia Local direct innoculation Volkman s canals in Haversian bone system thru metaphyseal bone to subpereosteal space Arnold et al JPO 2009

39 Acute Osteo and Septic Joint Common in joints in which the metaphysis is intraarticular Hip Shoulder Elbow Ankle Sonnen et al Ped Cl N Am 1996 Common Osteo Organisms Staph aureus Group B Strep H Influ b Salmonella MRSA Kingella kingae Pseudomonas Others

40 Acute Osteo Roine et al Clin Inf Dis 1997 Fever, pain, limited use of extremity WBC up in 40% ESR up in 91% CRP up in 97% Use CRP and exam to decide treatment change and antibiotic transition X-rays 2d soft tissue swelling 7 days pereosteal new bone 14 days osteolytic changes Bone Scan--localize MRI abscess, OR decisions CT later follow up bone changes

41 Cultures Trob et al Peds Surg Inf 1999 Culture of wound + 75% Blood culture + 50% Can take 48 hours to 7 days to grow Kingella kingae can take 2 weeks hemolytic gram negative organism

42 Treatment Surgery and Antibiotics Surgery Goal: Improve the local environment for antibiotic delivery Remove infected devitalized tissue Decompress abcess Facilitate antibiotic delivery Antibiotics Empirical coverage Health child: S aureus, strep pyogenes, strep pneumonia, H Influ b Neonate: group B strep, gm rods HIV: S pneumonia Sickle cell: salmonella MRSA now > 20 %

43 Indications for Surgery Overall Surgical rates for osteo 45-83% Abscess of soft tissue or bone Failure to respond to antibiotics Sequestrum Associated septic joint MRSA McCarthy et al JBJS 2004 Lamont et al JPO 1987

44 Antibiotics Sequential IV to oral therapy Adjust by culture and sensitivity testing IV 5-7 days If CRP comes down to normal PO 3 weeks If ESR comes down to normal stop antibiotics If CRP not coming down and exam unchanged second I and D or MRI Neonates will treated with IV only Peltola et al Pediatrics 1997 Belthur et al JPO 2010 Liu et al Iowa Orthop J 2013

45 Antibiotics alone--no Surgery Selected cases of very early extremity osteo without an abscess, uncomplicated osteo of pelvis, calcaneus, and spine, diskitis May wish to collaborate with a pediatric infectious disease doctor when treating a child with osteomyelitis Highland et al JBJS 1983 Jaakkola et al JPO 1999

46 Chronic osteo Recurrent infection Pathologic fracture Growth disturbance LLI DVT Septic pulmonary emboli Diarrhea, rash, thrombocytopenia, neutropenia, liver enzyme changes due to antibiotics Belthur et al JBJS 2012 Mantadikis Int J ID 2012 Complications

47 MRSA Osteo Van der Have et al JPO peds MRSA osteo Ave 2.4 debridements needed 12 admitted to PICU 4 developed organ failure 7 DVT and septic emboli DVT risk CRP > 6 Surgery performed Age > 8 MRSA on culture

48 Pathological fracture with MRSA osteo Belthur M JBJS 94A: cases MRSA in 15 Ave age 8 Ave time to fracture 72 days MRI sub-periosteal abscess USA pulsotype Recommend prolonged protected wht bearing

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50 Case #4 10 yo male with swollen knee 2 days Recently deer hunting with dad T 100 Can bear weight Knee ROM 5-95 WBC 15 k ESR 36 CRP 1.9

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54 Aspiration Thin yellow fluid Negative string sign 91,000 cells 60% neutrophils Gram Stain negative for organisms, WBC s present Lyme titers drawn Will be run in 4 days by the lab Treatment?

55 Borrelia burgdorferi spirochete Deer tick bite Takes 24 hours of tick attachment for transfer of spirochete Affects skin, heart, CNS, joints, eyes Ryan Pediatrics 2000 Tory J Rheumatol 2010 Lyme Pearls

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58 Brady AAP Com ID: Pediatrics 1991 Stage 1: 1-30 days Rash, erythema migrans, fatique, arthralias, HA, fever, chills, stiffness Stage 2: weeks to mo Migratory polyarthritis, CN VII neuropathy, meningitis Stage 3: mo to years Arthritis Knee #1 Chronic arthritis Acrodermatitis chronica atrophicans cigarette paper skin

59 Serology Elisa Western Blot PCR Culture on Barbour Stoenner Kelly medium Delays in serology results can result in unneeded surgery Aiyer Orthopaedics 2014 Walrath JCO 2014 Treatment Oral antibiotics 30 days Doxycycline > age 8 Amoxicillin IV ceftriazone or cefotaxime or pen G for carditis, meningitis, arthritis Synovectomy: chronic case

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61 Case #5 16 yo boy with 2 weeks of left knee pain High school soccer star Not in season Temp 99.9 WBC 15k ESR 39 CRP 2.1

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63 Radiologist reading: Osteomyelitis left posterior distal femoral metaphysis-- Brodie s abscess

64 Gram stain: negative Cultures: no growth at 48 hours

65 Lent Johnson MD Donald Sweet MD AFIP: Armed Forces Institute of Pathology Biopsy all infections and culture all tumors

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68 Chemo 100% necrosis, no viable tumor Hinged knee patella resurfacing limb sparing procedure by my partner orthopaedic oncologist

69 Summary Describe the Kocher/Caird criteria for differentiating a septic hip from toxic synovitis Describe the clinical presentation of discitis Identify the complications associated with MRSA osteomyelitis List the manifestations of Lyme disease Biopsy every infection

70 Thank You

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