Recognize Common Presentations of Pediatric Orthopedic Emergencies

Andrea Marmor, MD Associate Clinical Professor, Pediatrics UCSF –San Francisco General Hospital

 Recognize common presentations of pediatric orthopedic emergencies  Practice evidence‐based diagnosis and treatment strategies for pediatric orthopedic emergencies  Panda is a 16 mo old girl brought to the ED for “crying nonstop”  She has been “not herself” for about a week, refusing to walk, always wants to be held, screams with diaper changes, and sleeping poorly  This evening, unable to fall asleep, so brought to ED

 T= 38, P 160 (crying), R 32, BP 100/60  Well‐appearing, consolable when held, non‐ toxic, supple neck  Full rotation at knee, ankle, hip  No tenderness or swelling of joints or bones  Screams when put on back on table, and when manipulating legs  ? tenderness over middle of spine, normal neuro exam A. CBC, CRP, ESR B. AP and frog‐leg view of hips C. Aspiration of hip D. Plain films and MRI of spine E. Lumbar puncture

MRI lumbar spine: diffuse bony edema of L4 and L5, with enhancement of the disc. T1 +contrast (left) and T2 (right). (from Arthurs et al, 2009)  Inflammatory/infectious etiology . Diagnosis commonly delayed . Refusal to walk/sit/limp/crying > back pain  Recent 18 year series (Fernandez, 2000) . Mean age: 2.8 years . Only 28% febrile . Mean days of symptoms = 22

Fernandez, Pediatrics, 2000

 Diagnostic pearls: . Inflammatory markers poor predictors (may be normal) . MRI best sensitivity/specificity ▪ 76% seen on plain film (narrowing of disc @ 2‐4 wks) . Consider scintigraphy – sensitive but non‐specific  Management . Blood cultures rarely positive . Parenteral antibiotics (vanco, clinda) recommended ▪ In some series, patients did well without antibiotics . Follow ESR/CRP  Kodiak is a 4 week old boy brought in for “crying nonstop”  Seen by PCP yesterday, told it was colic  Not feeding well, and seems to cry more with the 5 S’s….  PMH: ex‐ 32 weeker, got “a few days” of antibiotics after birth, no other illnesses

 T= 36.0, P 190, R 50, BP 90/50  Very fussy, inconsolable  Flat fontanelle, well‐perfused, no rash  Slight erythema/warmth/swelling of left calf NEXT STEPS?

 This is an ill‐appearing, hypothermic neonate  You obtain blood cultures, a CRP/ESR and an LP  Plain film of left leg:  Osteomyelitis of the tibia

 Hematogenous most likely cause in pediatrics  Multifocal disease > in neonates/S. aureus  Diagnosis: . CBC: most helpful to R/O other conditions . ESR/CRP: variable sensitivity (normal reassuring if low suspicion); PCT may be better . Blood cultures: poor sensitivity, but helpful if + . Plain films: may show findings earlier in neonates . MRI: 97% sensitive/92% specific  Neonatal: . S. aureus (MRSA), E, Coli, GBS (late‐onset) . Vancomycin and cefotaxime  Infants/kids: . S. aureus (MRSA), GAS: vancomycin . Kingella? Add cefazolin . Sickle cell? Add ceftriaxone

 Gobi is a 6 mo old girl, brought in for “crying nonstop”  Usually consolable when held, but now it seems to make her cry more  Dad notes that she seems to be breathing fast, but otherwise has been afebrile, eating well, and no other symptoms  No PCP identified, but has been “healthy”  T 37.3, P 130, R 45, O2 sat 99%  Well‐nourished, comfortably tachypneic, no rashes/bruises, smiles and coos when sitting in dad’s lap  Screams when you pick her up, and will not lie on her back  You are able to range all of the limbs without difficulty, the rest of the exam is normal  Virtually pathognomonic for abuse  Can be missed on plain films  Let radiologist know what you are looking for…

 Thoracic cage, sternum, scapula, spine  Metaphyseal corner lesions (MCL)/bucket handle fractures “TODDLERS’ FRACTURE”

 Consider in infant/toddler with limp  May be due to unrecognized trauma . When stable, minimal symptoms  Imaging: Multiple views may be necessary  Consider child abuse if: . Multiple fractures, < 12 mo, mid‐shaft fracture

 13 yo Atlas has been limping for 3 mo  Complaining of L knee pain 4 months ago, but able to play soccer  Exam: . Well‐appearing, mildly obese male . Tanner IV, VS WNL for age  Lies with L leg flexed and externally rotated  Obligate external rotation on flexion of L hip  Internal rotation of L hip severely limited  Knee exam normal Normal Abnormal  Fast facts: . Average age 11.2 in girls/12.7 in boys – decreasing? . Usually idiopathic, 20% bilateral . Black > Hispanic > Asian > Caucasian  Diagnosis: AP and bilateral frog‐leg views  Management: surgical . Stable (90%) = able to weight bear . Unstable = NWB immediately (20‐50% risk of osteonecrosis)

 AP view  Frog’s Leg view  Avascular necrosis of the femoral head . Ischemia ‐> collapse ‐> remodeling . More common in boys, age 4‐8 at onset . Etiology: unknown (trauma, radiation, steroids may also cause ANFH)  Treatment: Immediate orthopedic referral  75% of cases resolve spontaneously with remodeling of femoral head

 Ussuri is a 5 year old boy with 1 week of R knee pain and limp  Maybe fell playing soccer last week: not getting better, knee seems swollen  No previous bone/joint problems  T39.1, non‐toxic, pain with weight on R leg  R leg: knee is swollen, erythematous and warm, with decreased extension/flexion  Full ROM hip and ankle  Plain films show a small joint effusion  Labs: . WBC =12,000, ESR = 15, CRP =75 mg/dL

 TS = Self‐limited inflammation of hip/knee  Differentiation from septic arthritis?  Kocher criteria: . WBC >12, ESR > 40, CRP >2mg/dL, temp >38.5, unable to bear weight . Validation? Variable PPV/NPV  General principles: . No prediction rule has 100% NPV . If suspicion is low, and BOTH ESR/CRP are normal (<20; <2) ‐> SA unlikely  Most common cause of hip pain in kids 3‐10 years of age  Etiology unknown  Management: NSAID’s, rest  1‐2% develop LCP

 Joint aspiration reveals 40,000 WBC  What is your next step?  Steroids prior to abx: . Reduce duration of sx, treatment and hospitalization and improve long‐term outs  Antibiotic choice . Vancomycin for good MRSA/GAS coverage . + cefotaxime in neonate (E Coli) . + consider cefazolin for Kingella in kids < 3 . + ceftriaxone in teens/sickle cell

Harel 2011; Odio 2003

 Nandi is a 15 yo girl complaining of R knee pain for 2 months  Pain is intermittent, improves at night  Told she has “growing pains”  No specific trauma, but has been unable to play basketball  Exam: tender mass distal R thigh, otherwise normal A. Age 15 B. Improves at night C. Unable to play basketball D. Mass/tenderness on exam E. All of the above

Codman’s triangle Calcified soft tissue mass

Osteosarcoma of distal femur  Osteosarcoma > Ewing’s  Peak age: 13‐16, boys:girls = 1.5:1  Delay in dx common: average 2‐3 mo  Clinical: . Intermittent pain, improves at night . Mass in 30‐40% . Long bones most frequently involved . Constitutional symptoms are rare

Osteosarcoma: sunburst reaction Ewing’s Sarcoma: Onion‐skinning Pelvis> long bones  Pedi orthopedic emergencies may present as crying, limp or refusal to walk . Consider in neonates/infants with unexplained fever  Diagnosis/Treatment: . MRI = study of choice for discitis, OM . Plain films sufficient to diagnose SCFE, LCP and bone malignancies (but get the right views!) . CRP/ESR: if normal = reassuring against septic arthritis (but get fluid if concern is high) . Steroids before antibiotics in SA enhances recovery FAST FACTS AND PEARLS FOR PEDIATRIC ORTHOPEDIC EMERGENCIES UCSF High Risk Emergency Medicine, May 23, 2014 ▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪ 1. DISCITIS Epidemiology:  Mean age of 2.8 years,  Duration of sx shorter with discitis than OM; less likely to be febrile than OM  Infectious etiology? Unclear. Organism rarely recovered  Delay in diagnosis is common (1‐2 weeks average) Clinical:  Infant: refusal to sit, uncomfortable with diaper change  Toddler: refusal to walk, progressive limp (63‐85%), may have back pain (27% in one study)  Crying/uncomfortable child, refusing to walk/sit, with normal hip/knee exam should raise concern for discitis  May be afebrile: more likely to be febrile with vertebral osteomyelitis (Fernandez, 2000) Labs:  ESR correlated best among inflammatory markers, but some patients have mildly elevated or normal ESR Radiography:  Plain film: disc narrowing usually visible 2‐4 wks after onset of sx o Fernandez, 2000: 76% had abnormal radiographs  MRI: diagnostic in most (85‐100%), and may improve time to diagnosis Treatment:  Anti‐staphylococcal antibiotics (clinda or vanco in MRSA area) for 6 weeks  Case series have reported as high as 50% resolution without antibiotics (eg: Fernandez, 2000)

Pearl: Consider discitis in the uncomfortable infant or toddler refusing to walk or sit, with a normal joint/bone exam

▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪ 2. OSTEOMYELITIS Epidemiology  Incidence highest in 1st 5 years of life (1/2 are younger than 5)  In kids, a disease of healthy population Pathophysiology  Hematogenous source is most common type of OM in peds o Direct incolulation: rare in kids, most likely in foot (pseudomonas)  Organisms vary by age: S aurus, H flu, GAS and GBS, enterobacter  S aureus may be associated with multiple sites  Long bones (femur, humerus, tibia) most often involved Clinical facts by age:  Neonate o Typically occurs in those with risk fx, including prematurity and previous infection (50%) o Multi‐focal disease more common (likely due to MRSA) o Fever may be absent o S aureus, GNR, GBS  Toddlers: o Fever in 40‐80%, localized pain in 56‐95% o Limp often a presenting complaint: decreased mobility in 50‐85% o Unlike those with SA, passive ROM of joint may be normal o Vertebral infections: more likely involve the disc

Andrea Marmor, MD UCSF High Risk Emergency Medicine May, 2014 o S aureus and GAS  Older Kids: o More likely to have localized pain o Brodie’s abscess: occurs most commonly in teens Differential dx:  Neonate/Infant: occult fx, other infection, malignancy (rare) NM disorder,  Toddler/kid: septic arthritis, cellulitis, malignancy, bone infarction, Caffey’s disease (infantile cortical hyperostosis)/fibrodysplasia ossificans progressive Labs  Labs should be interpreted in light of clinical suspicion  ESR: o 70‐100% sensitive; lower sens in puncture‐related OM (Harris, 2011)  CRP: o Prospective trial (Unkila‐Kallio): CRP performed as well as ESR o Jaakkola and Kehl: only 47% sensitive  PCT better predictor of OM than other bone/joint infections, but sensitivity still poor o Butbul‐Aviel, 2005: PCT value was elevated in 7 patients (58.3%) with osteomyelitis, only 3 children (27.2%) with septic arthritis and NO children with other (benign) diagnoses  CBC o Generally lacks sens/spec, but may identify other conditions (eg: leukemia) o Lower sensitivity (12‐58%)  Blood cultures o Poor sensitivity (< 50%) – but may be helpful in isolating organism (eg: Kingella – fastidious org, longer to grow) o Only 40‐60% of bone cultures are + Imaging:  Plain film: evidence by 10‐21 days (in neonates, may be apparent by 7‐10 days)  Scintigraphy may be useful when attempting to localize infection (80‐100% sens/70‐96% spec)  MRI: best imaging modality 97% sens/92% spec Treatment  Neonate: cefotaxime + vanco  Older infants/kids: vancomycin (+nafcillin if known MSSA) o Kingella; susc to cephalosporins but resistant to vanco/clinda: consider adding cefazolin if suspected  Sickle cell; add ceftriaxone for salmonella/H. flu

Pearl: Consider osteomyelitis in neonates with FWS, and cover empirically for GBS, enterococcus and S. aureus

Pearl: Osteomyelitis is most often hematogenous in the pediatric population

▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪ 3. TODDLERS’ FRACTURE: . Definition: a spiral fracture of the distal tibia, typically associated with the accidental twisting of the distal leg that occurs when a toddler catches their foot while running/walking . Toddlers’ fracture may be a subset of CAST fractures (childhood accidental spiral tibial fractures) . Accidental fractures typically occur in distal ½ of tibia, without displacement Age: . In one series, 1/3 occur in kids < 3, NONE in kids < 12 mo (Mellick, 1999) . Overall, the majority of fractures of abuse occur in kids < 12 mo:

Andrea Marmor, MD UCSF High Risk Emergency Medicine May, 2014 . Accidental fx are RARE in kids < 12 mo Diagnosis: . Initial radiographs may be normal in 43% of cases . Internal oblique view best for visualizing the spiral fracture

Pearl: A spiral tibial fracture in a child < 12 months should prompt concern for child abuse

▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪ 4. SCFE Epidemiology:  Average age: 12.7 years for boys and 11.2 years for girls, o Near the end of linear growth, prior to menarche/ Tanner IV o Age decreasing over time: earlier puberty?  Lehmann (2006): o Rates almost 4 x higher in blacks, 2.5 x higher in Hispanics and 1.62x higher in Asian/Pacific Islanders compared to white children  Obesity is recognized as a strongly associated factor of SCFE. o Increased BMI increases the shear stress across the physis, thus weakening it and causing a slip. The varying surge and level of hormonal activity associated with adolescent growth spurt may also contribute to the cause of SCFE  Commonly bilateral (~20%)  Rarely the result of an endocrine or metabolic disorder  Delay in diagnosis worsens prognosis Clinical Factors:  History o Typically present with knee, hip, groin, thigh pain or all o May be trivial trauma or discomfort (painless limp also common) o Acute major trauma is rarely involved; gradual onset of symptoms and deformity (external rotation) is more common  Exam: o Limited internal rotation is UNIVERSAL o External rotation of extremity o Obligatory external rotation with passive flexion of 90 degrees Diagnosis:  Radiology: plain films diagnostic in most, although may be negative with early/posterior slip o AP and frog‐leg lateral (frog‐leg view more sensitive) o Important to visualize both hips o Klein’s line (AP view): line drawn along femoral neck should intersect the lateral portion of the femoral head – if not, suspect SCFE Management:  Treatment is surgical, with stabilization across the physis by in‐situ pinning  Urgency based on stability: o Stable = able to bear weight (>90%) . Manage surgically as soon as possible . May progress to a more severe or unstable slip o Unstable = unable to bear weight (even with support) . Make non‐weight bearing immediately and admit . Risk of osteonecrosis 20‐50%)

Pearl: Always get bilateral hip views in suspected SCFE: 20% are bilateral

Andrea Marmor, MD UCSF High Risk Emergency Medicine May, 2014

▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪ 5. LEGG‐CALVE‐PERTHES DISEASE  Idiopathic avascular necrosis of hip  Epidemiology/Presentation o Clinical: Insidious onset of limp, with pain often referred to thigh or knee o Peak incidence between 5 and 7 (seen between ages 3 and 12) o 10% of cases are familial o Male: female ratio = 4:1  Exam: Limited internal rotation of hip, may result in atrophy of thigh/buttocks o Galeazzi test (leg length discrepancy) and Trendelenberg test (for unilateral gluteal muscle weakness) may be positive o Trendelenburg test also abnormal in SCFE, DDH ‐ suggests hip pathology  Diagnosis: o Generally visible on plain film, although initial radiographs may be normal o Obtain AP and lateral films, and views of both hips. o Repeat if symptoms persistent  Management: make NON‐WT‐BEARING immediately, and obtain orthopedic consultation

Pearl: Findings suggestive of a SCFE in younger child (5‐7 years of age) should prompt concern for Legg‐Calve‐Perthes Disease

▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪ 6. SKELETAL MALIGNANCIES: OSTEOSARCOMA VS EWING’S SARCOMA

Osteosarcoma Ewing’s Sarcoma “Growing pains” Origin Primitive bone mesenchyme Poorly differentiatiated Unknown (NOT caused by (?mesenchyme?) growth!) Gender Boys > girls (1.5:1) Boys > girls (1.5:1) Girls> boys Age Peak 13‐16 (growth spurt) Peak 13‐16 2‐12 years Adults > 65 Can be seen into 40’s Race Black> Caucasian Caucasian> Black/Asian None Frequency Rare; most common bone Rare; 2nd most common bone Common (10‐20%) malignancy malignancy Location Metaphyses of long bones (distal Pelvis > metaphysis/diaphysis of More common in lower femur> proximal tibia, proximal LE long bones > spine extremities humerus) Clinical Signs/  Intermittent local pain/  Intermittent local pain/  Nightly bilateral, deep Symptoms tenderness tenderness pain in thigh/calf  Rarely at night  Rarely at night  Absent during day  +/‐ mass (~30‐40%)  +/‐ mass (~30‐40%)  No physical findings  Average 2‐3 months duration  Average 3‐4 mo duration  Chronic, episodic pattern  Constitutional symptoms rare  Constitutional symptoms: 10‐  Otherwise normal activity 20% Radiographic  Lytic/sclerotic mass  “Moth‐eaten” lytic/sclerotic None appearance  Calcified soft tissue mass mass  “Sunburst” periosteal reaction  “Onion‐skinning” of periosteum

Pearl: “Growing pains” should never cause pain during the day, or interfere with activity

Andrea Marmor, MD UCSF High Risk Emergency Medicine May, 2014 ▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪ 7. SEPTIC ARTHRITIS Epidemiology/Pathophysiology  80% lower extremity (hip and knee most common)  10 % more than one joint Causes  Neonates/infants = GBS, N. gonorrhea, E.coli, S. aureus  Infants/Toddlers: S. aureus (including MRSA) + Kingella kingae o Kingella = gram negative coccobacillus, an emerging pediatric pathogen o Nationwide study of Kingella (Dubnov‐Raz, 2010): . 96% of children with Kingella were <3 . 53% of infections were skeletal infections . 43% of infections were bacteremia Diagnosis  Also consider: Toxic Synovitis, JIA, post‐strep arthritis, serum sickness, trauma, SCFE, LCP  Labs: o ESR and CRP better negative than positive predictors o Eg: CRP < 1 mg/dL has NPV of 87% (Levine 2003) o CRP peaks 36‐50hrs after onset of infection o PCT a poor predictor: only 27% sensitivity in one study (Butbul‐Aviel, 2005)  Radiography o Plain radiographs: . May demonstrate joint effusion, but not sensitive . Frog leg view of hips: may increase sensitivity for joint effusion . Better to R/O other bone abnormalities o Ultrasound: . May identify and quantify joint effusion, high NPV for hip arthritis o Bone scan: . Generally not indicated, unless searching for a source of fever, or osteo suspected o MRI: . May help distinguish b/w SA and TS/ . Can evaluate comcominant osteo or abscess  Fluid: o Best diagnostic test, but studies inconsistent due to varying gold standards o Higher WBC associated with higher likelihood of SA o WBC > 50 K with > 90% neuts suggests SA, but is not 100% sensitive or specific Treatment  Antibiotics o Neonate (< 3 mo): . Bugs: S. aureus, GBS, E. Coli . Drugs: vanco + ceftriaxone or cefotaxime . Consider gonorrhea if risk factors present o Infants/kids (> 3 mo): . Bugs: S. aureus, GAS (Kingella in kids < 3 yrs) . Drugs: vancomycin or clindamycin . Consider adding cefazolin for Kingella in kids < 3 years . Consider adding CTX in teens (N. gonorrhea) or sickle cell (Salmonella spp)  Corticosteroids: o Dexamethasone before antibiotics speeds recovery and improves long‐term outcomes o Harel 2011: Shortened duration of fever, inflammation, parenteral therapy and hospital stay

Andrea Marmor, MD UCSF High Risk Emergency Medicine May, 2014 o Odio 2003: Shortened hospital stay and reduction in residual dysfunction at 6 and 12 months o Recs: Dexamethasone 0.15mg/kg IV before antibiotics, and q6h for 4 days

▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪ 8. SEPTIC ARTHRITIS (SA) VS TRANSIENT SYNOVITIS (TS) . Both present with similar symptoms, in similar joints, and in similar patient populations . Multiple studies have attempted to develop a clinical prediction rule that can identify children at low risk of SA Kocher Criteria . Kocher (1999) found that 5 findings were associated with septic arthritis (99.7% positive predictive value, AUC of .96) 1. Fever ≥38.5º C (101ºF) 2. Inability to bear weight 3. White blood cell count >12,000/mm3 4. Erythrocyte sedimentation rate >40 mm per hour 5. C‐reactive protein > 2.0 mg/dL (20 mg/L) Subsequent Validation of Kocher criteria: . PPV varies from 59‐93% in retrospective and prospective studies (Kocher 2004, Luhmann 2004, Caird 2006), . NPV only 83% (Caird) Other predictive models:  Luhmann, 2004 (retrospective) o 3 variables had PPV of 71% for septic arthritis: 1. History of fever 2. WBC of >12K 3. Previous health‐care visit  Singhal, 2007 (retrospective) o A CRP > 20 mg/l had OR of 81.9 o 2 determinants 1. Weight‐bearing status 2. CRP > 20 mg/l o Absence of both: < 1% had septic arthritis o Presence of both: 74% had septic arthritis  Pakkonen, 2010 (prospective) o Best sensitivity (98%) for SA with combined ESR (>20) and CRP (>20 mg/L)  Caird 2006 (prospective) o C‐reactive protein level of >2.0 mg/dL (>20 mg/L) was a strong independent risk factor and a valuable tool for assessing and diagnosing children suspected of having septic arthritis of the hip.

Pearl: In differentiation SA and TS, take into account the entire clinical picture . If suspicion is high, obtain hip ultrasound and arthrocentesis even if labs are normal . If suspicion is low, and CRP/ESR are normal, unlikely to have SA

Andrea Marmor, MD UCSF High Risk Emergency Medicine May, 2014 ▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪▪ REFERENCES: 1. Arthurs OJ, et al. The toddler refusing to weight‐bear: a revised imaging guide from a case series. Emerg Med J 2009;26:797‐801 2. Bhatia NN, Pirpiris M, Otsuka NY. Body mass index in patients with slipped capital femoral epiphysis. J Pediatr Orthop. 2006 Mar‐Apr;26(2):197‐9. 3. Brown R, Hussain M, McHugh K, et al. Discitis in young children.J Joint Bone Surgery (Br)2001;83‐B:106– 11. 4. Butbul‐Aviel Y, et al. Procalcitonin as a diagnostic aid in osteomyelitis and septic arthritis. Pediatr Emerg Care. 2005 Dec;21(12):828‐32. 5. Caird MS, et al. Factors distinguishing septic arthritis from transient synovitis of the hip in children. A prospective study. J Bone Joint Surg Am. 2006 Jun;88(6):1251‐7. 6. Dodwell ER. Osteomyelitis and septic arthritis in children: current concepts. Curr Opin Pediatr 2013; 25(1): 58‐63 7. Dubnov‐Raz G, et al. Invasive pediatric Kingella kingae infections: a nationwide collaborative study. Pediatr Infect Dis 2010; 29(7): 639‐43 8. Fernandez M, Carrol CL, Baker CJ Discitis and vertebral osteomyelitis in children: an 18‐year review. Pediatrics. 2000;105(6):1299 9. Gholve PA, Cameron DB, Millis MB. Slipped capital femoral epiphysis update. Curr Opin Pediatr. 2009 Feb;21(1):39‐45. 10. Harris JC, et al. How useful are laboratory investigations in the emergency department evaluation of possible osteomyelitis? Emerg Med Australas. 2011 Jun;23(3):317‐30 11. Harel L, et al. Dexamethasone therapy for septic arthritis in children: results of a randomized controlled study. J Pediatr Orthop 2011; 31(2): 211‐5 12. Karabouta Z, et al. Discitis in toddlers: a case series and review. Acta Paediatrica 2005; 94(10): 1516‐1518 13. Kocher MS 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‐A(8): 1629‐35 14. Lehmann C, et al. The epidemiology of slipped capital femoral epiphysis: an update. J Pediatr Orth 2006; 26(3): 286‐290 15. Loder RT, Starnes T, Dikos G, Aronsson DD. Demographic predictors of severity of stable slipped capital femoral epiphyses. J Bone Joint Surg Am 2006; 88:97–105. 16. Luhmann SJ, 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‐A(5): 956‐62 17. McCarville MB. The child with bone pain: malignancies and mimickers. Cancer Imaging. 2009 Oct 2;9 Spec No A:S115‐21. 18. Mellick LB, et al. Childhood accidental spiral tibial (CAST) fractures. Pediatr Emerg Care 1999; 15(5): 307‐9 19. Odio CM, et al. Double blind, randomized, placebo‐controlled study of dexamethasone therapy for hematogenous septic arthritis in children. Pediatr Infect Dis J 2003; 22(10): 883‐889 20. Pääkkönen M, Kallio MJ, Kallio PE, Peltola H. Sensitivity of erythrocyte sedimentation rate and C‐reactive protein in childhood bone and joint infections. Clin Orthop Relat Res. 2010 Mar;468(3):861‐6. Epub 2009 Jun 17. 21. Singhal R, Perry DC, et al. The use of CRP within a clinical prediction algorithm for the differentiation of septic arthritis and transient synovitis in children. J Bone Joint Surg Br. 2011 Nov;93(11):1556‐61. 22. Sultan J,Hughes PJ. Septic arthritis or transient synovitis of the hip in children: the value of clinical prediction algorithms. J Bone Joint Surg Br 2010; 92(9): 1289‐93 23. Widhe B, Widhe T. Initial symptoms and clinical features in osteosarcoma and Ewing sarcoma. J Bone Joint Surg 2000; 82(5): 667‐

Andrea Marmor, MD UCSF High Risk Emergency Medicine May, 2014