Limp / limb pain

Question 1

Ddx for arthritis / limb pain

Answer 1

ortho: SCFE, legg-calve-perthes disease
functional: growing pains, fibromyalgia, conversion rxn
inflammatory: JIA, SLE, HSP, kawasaki’s
infectious: septic arthritis, osteomyelitis, transient synovitis, reactive arthritis, rheumatic fever, lyme

Heme: sickle cell, hemophilia /w hemarthrosis

trauma: #, soft tissue, osgood-schlatter, hypermobility
malignancy: leukemia, neuroblastoma, bone tumor

non-joint: testicular torsion/appendicitis (groin)

Question 2

Joint / limb pain red flags

Answer 2

• fever
• pain awakening from sleep
• lethargy
• redness
• non-weight bearing
• poor growth / weight loss
• trauma
• morning stiffness

Question 3

septic arthritis bacteria

Answer 3

S aureaus, GAS, strep pneumon

chlamydia / gonorrhea if sex active

kingkingae if <4

HiB if unimmunized

GBS + gram negs in neonates

Question 4

work-up for ?septic arthritis

Answer 4

CRP / ESR
CBC (high WBCs)
joint aspiration - culture + chemistries
blood cultures!
can US if exam unclear re effusion

Question 5

management of septic arthritis

Answer 5

IV antibiotics if improve then PO for 3 weeks, +/- joint washout

Question 6

complications of septic arthritis

Answer 6

joint damage (deformity, leg length discrepancy, poor ROM)

Question 7

empric antibiotic choice for septic arthritis

Answer 7

<3mo - cloxacillin + aminoglycoside

Child - cefazolin

Question 8

osteomyelitis most common sites

Answer 8

femur, tibia, humerus, fibula, radius

Question 9

?osteo work-up

Answer 9

CBC (high WBCs)
CRP/ESR
blood cultures
\+/- xray to r/o other conditions - fracture, tumor
bone scan, MRI to support dx
MRI = most sn/sp, but requires sedation

Question 10

osteo empiric Abx choice + tx length

Answer 10

neonate - cloxacillin + aminoglycoside

1-3mo old - ceftriaxone + aminoglycoside

Child - cefazolin

needs 4-6wks total (can step to oral)

Question 11

acute rheumatic fever timing + sx

Answer 11

2-4 weeks after GAS pharyngitis

arthritis
carditis
syndeham chorea
erythema marginatum
subcutaneous nodules

late: valve dx (MR, MS), joint laxity

ddx = post strep reactive arthritis - assume RF if unclear

Question 12

transient synovitis presentation

Answer 12

follow URTI

sudden onset painful hip (or knee), well, afebrile or fever <38.5, ambulating +/- limp

ages 3-8, esp boys

septic more likely if fever, not weight bearing, ESR/CRP high, WBC high

Question 13

work-up & management of transient synovitis

Answer 13

r/o septic A / osteo. 
WBC = normal
CRP <20
ESR <40
joint effusion on imaging (US, xray) -- may not need if all else normal

tx = NSAIDs, rest. Improves in 7-10d

Question 14

Reactive Arthritis Presentation

Answer 14

adolescents
inflammatory, 2-4wks after GI or GU infection
+/- urethritis and conjunctivitis

afebrile at presentation

Question 15

growing pains presentation

Answer 15

intermittent, non-articular pain
normal physical exam
night time
calf/shin, thigh
normal function
asymptomatic in day

ages 3-10

dx of exclusion
treatment: heat, massage, mild analgesia, reassurance

Question 16

malignancy causing limp - presentation

Answer 16

leukemia - red flags = pain awakening from sleep, constitutional (FTT, lethargy, night sweat, brusing).
dx: blood smear, bone marrow bx

bone tumor

neuroblastoma

Question 17

Juvenile Idiopathic Arthritis presentations

Answer 17

onset <16, at least 6wks
dx - exclude other causes

systemic: 1+ joint, daily fevers 2wks, 1 of evanescent (salmon macular) rash, hepatosplenomeg, pericard, serositis, lymphadenopathy
oligoarticular: <5 joints, girls 1-3yo, large joints exl hip, morning stiffness, if ANA+ve -> anterior uveitis (refer for eye screen)
polyarticular: 5+ joints, symmetric, small + large, RF -ve, if RF +ve adolescent girls, similar to adult RA
psoriatic: knees, hands, feet. Psoriasis rash. Nail changes, dactylitis.
enthesitis: heel, plantar fascia, patella. Older boys. assymmetric. Uveitis/iritis.

other

Question 18

treatment of JIA

Answer 18

oligo: steroid injections, NSAIDs, DMARDs = 2nd line,. eye screening, physio. +/- Biologics.

Systemic: NSAIDs, then pred. If can’t wean pred then biologics.

Question 19

SLE diagnostic criteria

Answer 19

Need 4 / 11:
malar rash
discoid rash
serositis
oral ulcers
arthritis
photosensitivity
blood disorders
renal impairment
ANA +ve
immunologic (anti dsDNA, Sm)
neurologic sx

Question 20

osgood schlatter disease

presentation + mechanism

Answer 20

overuse / stress injury of patellar tendon –> microavulsion of tibial tuberosity

presentation: pain + swelling at tibial tuberosity, usually athletic teens
tx: activity modification (don’t stop though), physio, ice, analgesia

Question 21

legg calve perthes disease presentation + etiology

Answer 21

self-limited avascular necrosis of capital femoral epiphysis

painful lump + decreased ROM, esp boys 4-10

Question 22

legg calve perthes disease diagnosis

Answer 22

MRI (more sensitive) or xray (joint wide, physis irregular, fragment, reossification, healing)

management: non-weight bearing, ortho referral, supportive, +/- abduction splints, +/- surgical osteotomy of prox femur to maintain head in acetabulum

Question 23

slipped capital femoral epiphysis presentation

Answer 23

limb held external rotation + flexion. Pain can be poorly defined, acute or months.

passive IR limited + painful

overweight males 10-14

associated: GH def, hypoT

Question 24

work-up of SCFE

Answer 24

xray - image both hips

TSH

Question 25

management of SCFE

Answer 25

urgent ortho referral
no weight bearing until surgery
epiphysiodesis, fix /w screw or bone graft

Question 26

toddlers fracture

Answer 26

oblique or spiral fracture of the tibia - limp or refuse to walk. Minor twisting trauma.

Question 27

how to evaluate growth plate fractures

Answer 27

SALTER HARRIS

I - S - straight across/slip
II - A - above (in metaphysis)
III - L - beLow
IV - T - through both sides
V - R - crushed

Any salter #, follow up for 1 year to ensure no growth abnormalities