Pediatric Septic Arthritis

Bacterial infection of a synovial joint causing acute purulent effusion and progressive articular cartilage destruction     A true orthopaedic emergency — irreversible glycosaminoglycan loss begins within 8 hours of onset

MD Saltuk Bugra TEKIN· Metin Sabancı Baltalimanı Bone Diseases Training and Research Hospital,Istanbul
May 7, 2026

1.  Epidemiology

•    Incidence: ~2× more frequent than acute haematogenous osteomyelitis in childhood

•    Peak incidence: early first decade; bimodal distribution (infants & school-age children)

•    Male predominance (approximately 2:1)

•    Distribution: 90% lower extremity

◦     Hip: ~54% of all cases (Taiwanese cohort, n=186)

◦     Knee: second most common

◦     Shoulder, ankle, elbow: less frequent

•    Overall incidence may be declining due to immunization programmes (H. influenzae Hib vaccine: 30% reduction in paediatric septic arthritis cases)

Age-specific Susceptibility

Neonates (<4 wk): Vessels from metaphysis penetrate into cartilaginous physis → simultaneous osteomyelitis + septic arthritis common; multifocal disease

Infants (<18 mo): Ogden-Lister blood supply to chondroepiphysis; 4 'at-risk' intracapsular metaphyses (proximal femur, proximal humerus, distal lateral tibia, proximal radius)

Older children: Classic haematogenous route; metaphysis outside joint; isolated septic arthritis more common

2.  Microbiology

Causative Organisms by Age

Age Group

Primary Pathogens

Key Notes

Neonates (<4 weeks)

Group B Streptococcus, S. aureus, Gram-negative rods (E. coli), N. gonorrhoeae

Multifocal disease common; often polyarticular

Infants (4 wk – 24 mo)

Kingella kingae ★, S. aureus, Group A Streptococcus, H. influenzae (unimmunized)

K. kingae is #1 organism <24 mo in immunized cohorts

Children (2 – 12 yr)

S. aureus ★★, Group A Streptococcus, S. pneumoniae

S. aureus in 60–90%; MRSA increasing

Adolescents (>12 yr)

S. aureus ★★, N. gonorrhoeae (sexually active)

Gonococcal arthritis: polyarticular, tenosynovitis, rash

Sickle Cell Disease

Salmonella spp., S. aureus

Salmonella: diaphysis; S. aureus: metaphysis

Kingella kingae — High-Yield Points

•    Fastidious gram-negative coccobacillus; oropharyngeal coloniser in young children

•    Gains bloodstream access via upper respiratory infection or oral mucosal breach

•    Transmitted child-to-child; outbreaks in day-care settings documented

•    Predilection for heart and musculoskeletal system

•    Culture pearls: inoculate directly into enriched blood culture media (BACTEC) → significantly improves recovery

•    Resistance profile: often resistant to vancomycin and clindamycin; sensitive to β-lactams

•    Diagnosis: real-time PCR assay most reliable (conventional culture frequently negative)

•    Prognosis: typically responds well to β-lactams with few sequelae

MRSA — Clinical Significance

•    MRSA isolated in ~30% of paediatric musculoskeletal infections (vs 0% two decades prior — UTSW data)

•    Associated with higher rates of DVT, subperiosteal abscess, pyomyositis, ICU admission

•    Antibiotic options: vancomycin (IV) or clindamycin (if susceptibility confirmed by D-zone test)

•    Linezolid (oxazolidinone class): effective against MRSA/VRSA; limited paediatric data

•    MSSA is now acquiring MRSA virulence factors → comparable disease severity being reported

3.  Pathophysiology

Route of Infection

•    Primary: haematogenous bacteraemia → synovial seeding (no basement membrane in synovium → bacteria freely enter joint)

•    Secondary: contiguous spread from adjacent osteomyelitis (especially at intracapsular metaphyses)

•    Direct inoculation: foot puncture wounds, joint injections (less common)

Joint Destruction Cascade

•    Bacteraemia → synovial seeding → synovitis → fibrinous exudate → synovial necrosis

◦     Leukocytes, synovial cells, and chondrocytes release proteases, peptidases, collagenases

◦     Glycosaminoglycan (GAG) loss: first measurable change → begins within 8 hours

◦     Collagen destruction: follows GAG loss → visible cartilage damage

◦     Neovascularisation + persistent bacterial colonisation → chronic inflammatory infiltration

•    Critical concept: once enzymes are released, cartilage destruction continues even after bacteria are eradicated

Acute Phase Response in Septic Arthritis

•    Infection = continuous activation of the 'survival phase' of the acute phase response

•    Results in: overwhelming SIRS, consumptive coagulopathy, thrombosis of epiphyseal vessels

•    Thrombotic sequelae in the epiphysis: chondrolysis, joint resorption, physeal arrest

•    Bacterial 'hijacking' of coagulation via coagulase (S. aureus) and streptokinase (S. pyogenes) amplifies tissue damage

Why the Hip is Most Vulnerable

•    Femoral head blood supply enters at periphery of femoral neck → intracapsular pressure from purulent effusion → vascular occlusion → AVN

•    Entire proximal femoral metaphysis is intracapsular → contiguous osteomyelitis communicates directly with joint

•    Perlman et al.: signs of adjacent joint septic arthritis present in up to 40% of osteomyelitis cases

4.  Clinical Presentation

History

•    Pain is the most common symptom — young children may present as irritability, refusal to walk/use limb

•    Fever >38°C: reported in only 36–74% (not reliably present)

•    Preceding illness (URI, varicella): critical history — K. kingae, Group A Strep

•    Antecedent trauma: present in 30–50% — can trigger osteomyelitis/septic arthritis or can confuse diagnosis

•    Prior antibiotic use: blunts fever and lab values → maintain high index of suspicion

•    Duration: symptoms of septic arthritis are progressive; traumatic symptoms typically improve

Physical Examination

•    General: observe child unaware — posture, spontaneous movement, refusal to bear weight

•    Hip position: flexion + abduction + external rotation (reduces intracapsular pressure)

•    Pain with passive ROM: hallmark sign of septic arthritis

•    Erythema and swelling: may appear 24–36 hours after onset

•    Sympathetic effusion: suggests adjacent osteomyelitis (without joint irritability)

•    Hip joint: inaccessible to direct assessment — Trendelenburg sign, log-roll test

•    Axial joints (spine, SI): localise by percussion, compression, range of motion

Clinical Comparison: Septic Arthritis vs. Toxic Synovitis vs. JRA

Feature

Septic Arthritis

Toxic Synovitis

JRA

Fever

>38°C (variable)

Low-grade or absent

Low-grade (systemic JRA: spiking)

Pain severity

Severe, progressive

Moderate, fluctuating

Moderate; looks worse than it feels

Weight bearing

Refused

Painful but may weight-bear

Usually maintained

WBC (serum)

>12,000 (variable)

Normal

Variable

ESR

Usually >40 mm/hr

Normal or mildly elevated

Often elevated

CRP

Elevated (often >2 mg/dL)

Normal or mildly elevated

Elevated

Synovial WBC

>50,000 (typical)

<15,000

<100,000 (rarely >100,000)

Joint appearance

Worse than function

Correlates with symptoms

Worse than function

Resolution

Requires surgery ± ABx

Self-limiting (1–2 wk)

Chronic/relapsing

5.  Diagnostic Workup

Laboratory Tests

•    Principle: only blood/tissue culture, antibody titer, or PCR confirm infection — all other tests measure the acute phase response

Test

Sensitivity

Key Points

Timing

WBC count

25–73%

Least sensitive; check manual differential to exclude leukaemia

Immediate

ESR

85–95%

Elevated in 85–95% SA; rises 24–48 hr after onset; peaks day 3–5; slow to normalise (2–4 wk)

Delayed (48–72 hr)

CRP

92–98%

Most useful: rises within 4–6 hr, t½ = 17 hr; normalises rapidly with effective Rx; fails to fall → treatment failure

Early

Procalcitonin

Investigational

<0.3 ng/mL: low risk; >0.5 ng/mL: concern; rises earlier than CRP; more specific for bacterial vs. viral

Early

IL-6

Research only

First APR marker to rise; stored in MSK tissue; released immediately after injury; short half-life

Immediate

Blood culture

30–60%

Obtain before antibiotics; do NOT withhold antibiotics to obtain culture if child is unwell

Immediate

Synovial aspirate culture

30–80%

Inoculate enriched media (K. kingae); Gram stain positive in ~33%

Immediate

Synovial Fluid Analysis — Critical Values

Parameter

Normal

Transient Synovitis

Septic Arthritis

JRA / Inflammatory

Appearance

Clear, straw

Clear/xanthochromic

Turbid/purulent

Turbid/xanthochromic

WBC count (/mL)

<200

<15,000

>50,000 (typical)

15,000–100,000

PMN %

<25%

<50%

>75% ★

Variable

Glucose

= serum

= serum

<50% serum ★

Decreased

Culture

Negative

Negative

Positive 30–80%

Negative

PMN >75% is highly suggestive of septic arthritis even if WBC is <50,000/mL  |  A WBC of ≤50,000/mL found in 55% of culture-proven cases (Fink & Nelson)

Imaging

Plain Radiographs

•    Sensitivity 43–75%, Specificity 75–83%

•    Soft tissue swelling visible within 3 days (earliest plain film finding)

•    Joint space widening at hip: asymmetric vs. contralateral → suggestive of effusion (especially in neonates)

•    Bone changes: not apparent for 7+ days → late sign

•    Late untreated SA: joint space narrowing, bone destruction both sides of joint, osteonecrosis of femoral head

Ultrasound

•    Detects effusion (sensitivity ~95% for effusion, but cannot distinguish SA from toxic synovitis)

•    False-negative rate: 5% (especially in <24 hr symptoms or bilateral effusions — Gordon et al., n=132)

•    Best use: guide hip aspiration in the ED/radiology department

•    Cannot reliably differentiate pericapsular pyomyositis from septic arthritis

MRI — Imaging Modality of Choice for Complex Cases

•    Sensitivity 88–100%, Specificity 75–100%, PPV 85%

•    Detects: effusion, synovitis, cartilage damage, bone marrow oedema (↓T1, ↑T2), abscesses, AVN

•    Gadolinium enhancement: differentiates osteomyelitis (irregular geographic enhancement) from bone infarct (thin linear rim) and neoplasm

•    Yang et al.: SA more likely to show adjacent bone marrow signal abnormality + perisynovial soft tissue contrast enhancement (vs. toxic synovitis)

•    Sensitivity of MRI vs. bone scintigraphy for S. aureus osteomyelitis: 98% vs. 53% (Texas Children's Hospital, n=199)

•    MRI after surgery: not affected by recent surgical oedema; reliable for re-evaluation

•    Disadvantage: cost, frequent need for sedation/GA in young children

Bone Scan (Tc-99m)

•    Sensitivity 89–94%, Specificity 94%, Accuracy ~92%

•    Best for: unknown/multiple sites of infection, fever of unknown source

•    Limitation: cannot distinguish septic arthritis from osteomyelitis; 'equally increased uptake on both sides of joint' suggests SA

•    Cold scan: paradoxically associated with more severe disease (100% PPV for OM); suggests vascular thrombosis

•    Neonates: sensitivity only 30–86% — plain radiographs more helpful in this age group

6.  Kocher Criteria — Septic Arthritis vs. Toxic Synovitis of the Hip

The Kocher algorithm is the most widely used clinical prediction tool for differentiating septic arthritis from transient synovitis of the hip.

Kocher Predictors (Original 4 Variables — 1999)

•    1. Fever (history of fever)

•    2. Non-weight bearing

•    3. ESR ≥ 40 mm/hr

•    4. WBC > 12,000/mL

Predicted Probability of Septic Arthritis

Number of Predictors Present

Predicted Probability of Septic Arthritis

0

< 0.2%

1

3.0% (original) → 9.5% (prospective validation)

2

40.0% (original) → 35.0% (validation)

3

93.1% (original) → 72.8% (validation)

4

99.6% (original) → 93.0% (validation)

Updated Kocher-Philadelphia Algorithm (5 Variables)

•    CRP elevation added as 5th variable (Children's Hospital of Philadelphia)

•    5 factors present → 98% probability of septic arthritis

•    4 factors present → 93% probability of septic arthritis

  Critical Limitation

•    Prospective validation at a different institution (Luhmann et al.): 4 predictors → only 59% probability (vs. 99.6% in original study)

•    The Kocher algorithm cannot replace clinical judgement — use as adjunct, not as sole decision-making tool

•    In the acutely ill child, err on the side of surgical exploration

7.  Differential Diagnosis

Condition

Differentiating Features

Urgency

Transient Synovitis (Toxic Synovitis)

Self-limiting; recent URTI common; low-grade or no fever; WBC/CRP normal or mildly elevated; responds to NSAIDs

Outpatient

Acute Haematogenous Osteomyelitis

Point tenderness over bone (metaphysis); joint irritability mild (sympathetic effusion); bone scan/MRI localises

Urgent

Pericapsular Pyomyositis

Pericapsular muscle signal on MRI; effusion size smaller than SA; Vanderbilt: 2:1 pyomyositis:SA in 'rule out hip infection'

Urgent

Juvenile Rheumatoid Arthritis (JRA)

Gradual onset; polyarticular; joint looks worse than it feels; remains ambulatory; ANA/RF may be positive

Elective

Rheumatic Fever (ARF)

Jones criteria; exquisite pain out of proportion to effusion; migratory polyarthritis; recent strep infection

Medical

Lyme Arthritis

Endemic area; Borrelia serology + synovial PCR; WBC 47,000–64,000/mL

Medical

Psoas Abscess / Septic Sacroiliitis

Hip pain + groin/buttock pain; pain with SI compression; CT/MRI essential

Urgent

Leukaemia

Metaphyseal bands on XR; anaemia, thrombocytopenia; atypical WBC on differential; bone pain often multifocal

Emergency

PSRA (Post-streptococcal Reactive Arthritis)

Recent strep infection; does not fulfil Jones criteria; self-limiting; controversial role of prophylactic ABx

Outpatient

8.  Treatment

General Principles

•    Septic arthritis = surgical + antibiotic combination — antibiotics alone are INSUFFICIENT

•    Purulent joint fluid: proteolytic enzymes persist after bacterial clearance → joint must be decompressed

•    Do NOT withhold antibiotics to obtain cultures in an acutely ill child with exuberant acute phase response

•    Hip septic arthritis: treat as surgical emergency — risk of AVN with delay

Empiric Antibiotic Selection by Age

Age / Setting

Empiric Regimen

Rationale

Neonates (<4 wk)

Ceftriaxone or Cefotaxime + Oxacillin

Cover: Group B Strep, S. aureus, gram-negatives, gonococci

Infants <2 yr (unimmunized)

Cefuroxime or Ceftriaxone + Oxacillin

Cover: H. influenzae, K. kingae, Group A Strep, S. aureus

Children 2–12 yr (immunized)

Oxacillin or Cefazolin

Cover: S. aureus, Streptococcus spp., S. pneumoniae

Suspected MRSA

Vancomycin IV or Clindamycin (D-zone test negative)

Adjust when culture + sensitivity available

Sickle Cell Disease

Cefotaxime/Ceftriaxone (Salmonella coverage)

Add antistaphylococcal agent if S. aureus not excluded

Sexually active adolescent

Ceftriaxone (gonococcal coverage)

Consider additional MRSA coverage if no response

Specific Antibiotic Dosing Reference

Antibiotic

IV Dose

Oral Equivalent

Notes

Oxacillin

150–200 mg/kg/d ÷ q6h

Dicloxacillin 100 mg/kg/d ÷ q6h

Preferred for MSSA; risk of skin sloughing if extravasation

Cefazolin

100–150 mg/kg/d ÷ q8h

Cephalexin 100–150 mg/kg/d ÷ q6h

Excellent MSSA coverage; more convenient dosing

Vancomycin

40–60 mg/kg/d ÷ q6h

Not available orally

Monitor troughs (10–15 μg/mL); infuse over ≥60 min; red man syndrome

Clindamycin

40 mg/kg/d ÷ q8h IV

30–40 mg/kg/d ÷ q8h PO

Confirm MRSA susceptibility with D-zone test; excellent bone penetration

Ceftriaxone

50–100 mg/kg/d ÷ q12-24h

Not applicable

Gram-negative + gonococcal coverage; good for outpatient (once daily)

Linezolid

10 mg/kg q8h (<12 yr)

Available (same dose)

Reserve for VRSA/MRSA failures; monitor for thrombocytopenia

IV-to-Oral Transition Criteria

Criteria for Safe Oral Step-Down (All must be met)

•    Afebrile (no fever for ≥24–48 hours)

•    Clinically improved: reduced tenderness, improved ROM, no limp, return of appetite

•    CRP declining (trending toward normal) — not necessarily normalised

•    Child can swallow and is expected to absorb oral medication

•    Compliant family/carer confirmed

•    Susceptible organism identified OR empiric oral agent achieves adequate serum bactericidal titre (≥1:8)

Total Antibiotic Duration

•    Septic arthritis: minimum 3 weeks total (IV + oral combined)

•    Complicated cases (adjacent osteomyelitis, MRSA, abscess): 4–6 weeks

•    ESR normalisation: NOT required before discontinuation (may take 4–8 wk — unnecessarily prolongs therapy)

•    Use CRP as primary monitoring marker: short half-life (17 hr), responds within days of effective treatment

Monitoring During Treatment

•    Weekly labs: CBC (neutropenia risk), CRP, ESR, AST, ALT, creatinine

•    CRP serial monitoring: should decline daily with effective therapy; any plateau/rise → re-evaluate

•    Vancomycin: monitor trough levels every 3–4 days; also monitor BUN/creatinine

•    Clindamycin: monitor for C. difficile colitis, hepatotoxicity

•    If no clinical improvement within 48 hours → consider abscess, inadequate debridement, resistant organism, alternative diagnosis

9.  Surgical Treatment

Indications for Surgery

Surgical Indications

•    Synovial fluid WBC > 50,000/mL with clinical picture of septic arthritis → irrigate and debride

•    Septic arthritis of the hip → always surgical (emergency)

•    Failure to improve clinically within 48 hours of appropriate antibiotics

•    Concomitant subperiosteal/bone abscess requiring drainage

•    Gross purulence or positive Gram stain on aspiration

•    Neonate with septic arthritis (high risk of AVN, physeal damage)

Drainage Options by Joint

Joint

Preferred Approach

Alternative

Notes

Hip

Open arthrotomy (anterior approach) ★

Arthroscopic washout

TRUE EMERGENCY; posterior approach risks posterior capsular instability

Knee

Arthroscopic washout ★ or open arthrotomy

Serial needle aspiration (controversial)

Arthroscopic allows thorough debridement + lavage

Shoulder

Open or arthroscopic washout

Serial aspiration (limited data)

Ensure decompression of subscapularis recess

Ankle

Open or arthroscopic

Serial aspiration

Beware concurrent calcaneal/distal tibial OM

Elbow

Open washout

Arthroscopic (technical challenge)

Avoid posterior capsular injury

SI Joint / Pelvis

CT-guided percutaneous drainage or open

Image-guided aspiration

Often associated with psoas abscess

Anterior Hip Drainage — Surgical Technique Key Points

•    Patient position: supine with bump under affected hemipelvis (30–45° elevation)

•    Prep entire leg and buttocks into field — allows full intraoperative hip motion

•    Incision: transverse, ~1 fingerbreadth below ASIS (cosmetically superior to posterior)

•    Interval: between sartorius (femoral n.) and tensor fascia lata (superior gluteal n.)

•    Anterior capsulotomy: T- or H-shaped incision — avoid posterior capsule

•    Thorough debridement: remove all purulent material + fibrinous debris

•    Irrigation: copious normal saline lavage

•    Closure: leave closed suction drain within joint, exiting percutaneously lateral to incision

•    Arthrogram at closure to document capsular integrity

Arthroscopic vs. Open Drainage — Evidence Summary

•    Experimental staphylococcal SA model (rabbits): arthrotomy + lavage → no collagen degradation; aspiration alone → collagen destruction persisted

•    Knee: arthroscopic washout generally preferred — allows thorough visualisation and debridement of all compartments

•    No high-level RCT data specifically comparing arthroscopic vs. open for paediatric septic arthritis

•    'The stakes are high, risking lifelong arthritis' — err on the side of surgical joint debridement (Lovell & Winter)

10.  Complications & Sequelae

Short-term Complications

Long-term Sequelae

SIRS / Sepsis

Avascular necrosis (AVN) of femoral head

DVT (especially MRSA)

Physeal arrest → leg length discrepancy or angular deformity

Pyomyositis (adjacent)

Joint stiffness / reduced ROM

Adjacent osteomyelitis

Secondary osteoarthritis

Pathological dislocation (hip)

Coxa magna / coxa breva

Pulmonary embolism (rare)

Hip dysplasia (if treated in infancy)

Neonatal Septic Arthritis — Special Considerations

•    Highest risk of permanent sequelae due to vulnerability of cartilaginous epiphysis

•    Ogden-Lister blood supply: metaphyseal vessels cross physis → simultaneous epiphyseal + joint infection

•    Late presentations: hip dysplasia, subluxation, proximal femoral growth disturbance (as shown in Fig. 12-6, Lovell & Winter)

•    Early treatment (within 24–48 hr): better functional outcomes; delay → high AVN rate

•    Follow-up radiographs essential at 2 and 4+ years post-treatment (acetabular index, femoral head coverage)

11.  Follow-up Protocol

Timepoint

Clinical Assessment

Laboratory

Imaging

48 hr post-surgery

Fever resolution, ROM, wound check

CRP (should be declining)

None unless clinical concern

Day 5–7

Oral step-down decision

CRP, CBC, ESR

None routine

Week 2

Outpatient review

CRP, ESR, LFTs, renal function

Plain XR if no prior bony change

Week 3–4

Antibiotic discontinuation decision

CRP normalised? ESR trending

XR (hip: femoral head status)

3 months

ROM, gait analysis

ESR (may still be elevated)

XR (growth, early AVN signs)

6 months

Growth, limb length

None unless symptomatic

XR pelvis (AP)

1–2 years

Long-term sequelae screen

None unless symptomatic

XR (AVN, physeal arrest, dysplasia)

12.  High-Yield Summary — Board & Fellowship Pearls

Must-Know Points

•    Cartilage destruction begins within 8 hours — time to surgery is critical

•    S. aureus remains #1 pathogen at all ages; MRSA increasing

•    K. kingae: #1 pathogen <24 months in immunized children; needs enriched blood culture media; PCR most reliable

•    Kocher criteria: 4 predictors → ~93–99% probability of SA (validate prospectively: 93% at BCH, 59% at external sites)

•    Hip septic arthritis = surgical emergency; anterior approach preferred over posterior

•    Synovial WBC >50,000/mL → strong indicator of SA, but 55% of proven SA have WBC ≤50,000/mL

•    PMN >75% in synovial fluid is highly suggestive even when total WBC is lower

•    CRP: most useful monitoring marker (t½ = 17 hr; rises within 4–6 hr; rapidly normalises with successful Rx)

•    ESR continues to rise for 3–5 days after initiating successful therapy — do NOT use for early response monitoring

•    Culture-negative SA: treat empirically as staphylococcal disease — outcomes equivalent to culture-positive

•    IV-to-oral step-down: safe when afebrile + clinically improved + CRP declining; ESR normalisation NOT required

•    MRSA: vancomycin or clindamycin (confirm susceptibility); MSSA now acquiring MRSA virulence factors

•    Neonatal SA: highest risk of AVN, physeal arrest, hip dysplasia — long-term follow-up mandatory

•    Adjacent osteomyelitis: present in up to 40% of SA cases (Perlman) — always examine neighbouring joints

•    Enzymes released into joint continue to destroy cartilage even after bacteria are eradicated

References

1.  Flynn JM, Weinstein SL, Crawford H (eds). Lovell and Winter's Pediatric Orthopaedics, 8th ed. Philadelphia: LWW/Wolters Kluwer, 2020. Chapter 12: Musculoskeletal Infections.

2.  Tachdjian MO, Herring JA (eds). Tachdjian's Pediatric Orthopaedics, 5th ed. Philadelphia: Elsevier Saunders, 2014.

3.  Kocher MS, Zurakowski D, Kasser JR. Differentiating between septic arthritis and transient synovitis of the hip in children. J Bone Joint Surg Am. 1999;81(12):1662–1670.

4.  Kocher MS, Mandiga R, Zurakowski D, et al. Validation of a clinical prediction rule for the differentiation between septic arthritis and transient synovitis of the hip in children. J Bone Joint Surg Am. 2004;86(8):1629–1635.

5.  Luhmann SJ, Jones A, Schootman M, et al. Differentiation between septic arthritis and transient synovitis of the hip in children with clinical prediction algorithms. J Bone Joint Surg Am. 2004;86(5):956–962.

6.  Peltola H, Pääkkönen M, Kallio P, et al. Short- versus long-term antimicrobial treatment for acute hematogenous osteomyelitis of childhood. Pediatr Infect Dis J. 2010;29(12):1123–1128.

7.  Yagupsky P, Dagan R. Kingella kingae: an emerging cause of invasive infections in young children. Clin Infect Dis. 1997;24(5):860–866.

8.  Mignemi ME, Menge TJ, Cole HA, et al. Epidemiology, diagnosis, and treatment of pericapsular pyomyositis of the hip in children. J Pediatr Orthop. 2014;34(3):316–325.

9.  Martínez-Aguilar G, Hammerman WA, Mason EO Jr, Kaplan SL. Clindamycin treatment of invasive infections caused by community-acquired, methicillin-resistant and methicillin-susceptible Staphylococcus aureus in children. Pediatr Infect Dis J. 2003;22(7):593–598.

10.  Fink CW, Nelson JD. Septic arthritis and osteomyelitis in children. Clin Rheum Dis. 1986;12(2):423–435.