Case 17: 4yo - Orthopaedic

Question 1

how to differentiate accidental v. non-accidental bruising

Answer 1

ACCIDENTAL = bruises over bony prominences (shins, forearms) –> esp in toddlers, young active children

NON-ACCIDENTAL = bruises over well-cushioned areas (buttocks, back, genitalia)

Question 2

can you determine the age of a bruise by color

Answer 2

NO

not reliably

Question 3

LYME dz

• cause:
• presentation:
• dx:
• complication:

Answer 3

• cause: Borrelia burgdorferi (bacteria) on the deer tick
• presentation: erythema migrans + fever, malaise, fatigue, HA
• dx: clinically; (blood test only to rule out if negative)
• complication: ARTHRITIS (4w after skin lesion) = esp large joints closest to rash; one-off or recurring

Question 4

Developmental dysplasia of the hip

• RFs:
• presentation:
• dx:
• complication:

Answer 4

==> femoral head not properly aligned with acetabulum

• RFs: female, breech delivery, FFx of DDH, first born
• presentation: dysplastic, dislocatable, subluxated, dislocated
• dx: SCREENING= Ortolani, Barlow
• complication:

Question 5

define ortolani

Answer 5

assesses for a dislocated hip by abduction of the flexed hip with gentle anterior force.

Question 6

define Barlow

Answer 6

assesses for a dislocatable hip by adduction of the flexed hip with gentle posterior force

Question 7

what does septic arthritis mimic, and how do you differentiate

Answer 7

septic arthritis v. transient synovitis of the hip

***1) fever >38.5
2) non-weight-bearing
3) ESR >40
4) WBC >12000
**5)elevated CRP > 20
(more factors = more predictive of septic arthritis)

Question 8

septic arthritis v. transient synovitis of the hip

• cause:
• presentation:
• dx:
• tx:

Answer 8

== unlikely signs of severe local inflammation (erythema, warmth, swelling) b/c deeper

SEPTIC ARTHRITIS OF THE HIP

• cause: Staph aureus, Strep (neonate: group B; infant and children: Group A, pneumoniae); H. flu (unimmunized); Neisseria gonorrhea (adolescents); Kingella (kids <4yo)
• presentation:
• dx: US of hip + US-guided needle aspiration (arthrocentesis) of synovial fluid ==> turbid, increased WBC (mostly PMNs), low glucose, Gram stain + fluid culture
• tx: empiric + prolonged IV Abx (narrowed as needed), surgical I and D

TRANSIENT SYNOVITIS OF THE HIP

• cause: recent URI
• presentation: inflammation and swelling of the tissues around the hip joint; decreased ROM
• dx: no or low-grade fever; diagnosis of exclusion
• tx: rest, ibuprofen
• prognosis: pain resolves in 3-10d, with small chance of recurrence

Question 9

does transient synovitis of the hip predispose kids to arthritis in the future

Answer 9

NO

no serious /long-lasting consequences

Question 10

history taking in a child with a limp

Answer 10

“any bruising” ==> sickle cell disease

“prior episodes” ==> acute on chronic / recurring condition; repeated injuries ==> non-accidental traumma

“recent illness” ==> post-infectious etiology (URI)

“other sxs” ==> constitutional sxs (fever, malaise)

Question 11

important parts of a MSK exam

Answer 11

OBSERVATION

1) naturally moving, gait
2) examine unaffected limb first
3) examine joints directly above and below affected site
4) tenderness, warmth, effusion

Question 12

diffdx of acute refusal to walk

Answer 12

• LEUKEMIA = d/t infiltration of bone marrow by leukemic cells –> + limp, localized discomfort of jaw, long bones, vertebrae, hip, scapula, ribs + fever, weight loss
• OSTEOMYELITIS = Staph aureus, H. flu (if unimmunized) –> + pain, indolent course + fever
• REACTIVE ARTHRITIS = d/t GI/GU infection –> afebrile (+/- urethritis/conjunctivitis in adults)
• SEPTIC ARTHRITIS = + high fever
• TRANSIENT SYNOVITIS = acute onset of hip pain with NO other constitutional sxs, d/t post-URI + low-grde fever
• TRAUMA = sprain, occult fracture, non-accidental

Question 13

where may osteomyelitis in the ilium present with pain?

Answer 13

hip

Question 14

evaluation and management of painful hip

Answer 14

EVALUATION
1) WBC, CRP, ESR
==> infections (transient/septic arthritis); malignancies (leukemia); inflammatory conditions (JIA)

2) synovial fluid/blood culture ==> septic arthritis
3) XR of hip ==> trauma

MANAGEMENT
1) topical anaesthetic cream (lidocaine) @ site of injections / needle procedures

Question 15

what is the ibuprofen dosing for infants andkids?

Answer 15

Pediatric dose: 10 mg/kg every 6-8 hrs PO (maximum dose = 40mg/kg/24 hr PO)

Concentration of oral suspension: 100 mg/5 mL (20 mg/1 mL)

Question 16

diffdx of chronic refusal to walk

+ tx

Answer 16

(chronic, indolent, vague)
- JUVENILE IDIOPATHIC ARTHRITIS = <16yo, 1+ joints, for >6w –> systemic (+ fever, rash), oligoarthritis (+ knee, Asx iridocyclitis), polyarthritis (RF + or -), psoriatic, enthesitis-related.
==> anti-inflammatories

• SLIPPED CAPITAL FEMORAL EPIPHYSIS = in obese teen boys; with posterior displacement of femoral head/epiphysis thru cartilage growth plate –> limp, impaired internal rotation ==> +/- avascular necrosis of femoral head, destruction of articular cartilage
  ==> internal reduction of femoral head
• LEGG-CALVE PERTHES = avascular necrosis of capital femoral epiphysis of young boys, infectious/trauma/developmental/prothrombotic ==> +/- femoral head deformity, degenerative arthritis
  ==> casting and crutches
• AVASCULAR NECROSIS OF FEMORAL HEAD = d/t to loss of blood supply, from non/traumatic factors

Question 17

presentation of hip pain secondary to effusion

Answer 17

==> septic arthritis, transient synovitis

pts will prefer to “open” hip capsule by holding hip capsule in flexion and external rotation

Question 18

is leg pain associated with osteomylitis position-dependent(i.e., child will prefer to hold limb in certain position)?

Answer 18

NO

but child will avoid standing alone, without support

Question 19

compare ESR v. CRP

- which rises more quickly? which is more specific?

Answer 19

ESR

• indirect measurement of fibrinogen (acute phase reactant) increase ==> increased cohesion of RBCs
• slow rise, slow fall (for weeks after clinical improvement)
• NONSPECIFIC = inflammation, pregnancy, anemia

CRP == faster rise (4-6h); peak @ 36-50h; fall within 3-7 days post
- direct quantification of acute phase response

Question 20

you diagnose a child with transient synovitis, but are concerned that there is a slight change that this is early / atypical presentation of septic hip / osteomyelitis. what things should caretakers watch out for?

Answer 20

• Persistent fever over 100.4° F
• Increased leg pain
• Redness or swelling of the leg
• A rash

Question 21

An 8-year-old obese male comes to the clinic with a chief complaint of right knee pain with the right foot medially rotated. On an exam the right knee is neither swollen nor erythematous but he is noted to have a limited ROM of the right hip. In addition, when he lifts his right leg, it externally rotates. The patient did not have a URI or any trauma preceding the onset of pain. The vital signs are normal at the time of the visit and he is well appearing and afebrile. What is/are the best next step(s) in management?

Single Choice Answer:
Please select one answer.
A AP and lateral x-ray followed by casting and crutches
B Bone scan
C AP and lateral x-ray followed up by internal reduction of the femoral head
D Aspiration of the knee
E Observation and weight reduction counseling

Answer 21

C

limited internal rotation

chubby == scfe

e AP and lateral x-rays are needed to diagnose a slipped capital femoral epiphysis, which is considered an emergency. This patient’s age group, his obesity, and the description of the external rotation of the right leg when the hip is flexed all suggest this diagnosis.

Question 22

A 6-year-old female comes to the clinic with a chief complaint of worsening right knee pain over the past month. On exam, you note generalized lymphadenopathy and splenomegaly. She coughs intermittently throughout the visit, and her mother explains that she is just getting over a cold. You note absence of tenderness, erythema, effusion or warmth over the hip, knee, or ankle joints. Her vitals are unremarkable except for a low-grade fever (100.8 F). Reviewing her chart, you note that she has lost 5 lbs since her visit 2 months ago. She sits with her right leg externally rotated but appears to be in pain despite trying several different positions, refusing to bear weight on that side. What is the most likely diagnosis?

 Single Choice Answer:
Please select one answer.  
A		Reactive arthritis	
B		Leukemia	
C		Osteomyelitis	
D		Transient synovitis	
E		Septic arthritis

Answer 22

B.

post URI
low fever 100.8
no weight bearing

+ WEIGHT LOSS
systemic symptoms such as weight loss, hepatosplenomegaly, and generalized LAD

Leukemia can present as bone pain due to replacement of bone marrow by leukemic cells. Patients may present with a limp or refusal to walk. Leukemia is associated with systemic symptoms such as low-grade fever, chronic/insidious joint pain, generalized LAD, weight loss, and/or hepatosplenomegaly.

Question 23

A 3-year-old girl comes to the clinic with a limp and a slightly externally rotated right hip. Which of the following signs/symptoms would you expect in the history or exam if a diagnosis of transient synovitis were made?

 Single Choice Answer:
Please select one answer.  
A		History of a recent upper respiratory tract infection	
B		High-grade fever	
C		Iridocyclitis	
D		Knee pain	
E		ESR of 110 mm/hr

Answer 23

A

Iridocyclitis = inflammation of the iris (the colored part of the eye) and of the ciliary body (muscles and tissue involved in focusing the eye). This condition is also called “anterior uvetitis” and “iritis”

Transient synovitis of the hip is associated with a low-grade fever and frequently occurs during or after a URI. Between 32% and 50% of children who present with transient synovitis had a recent upper respiratory tract infection. It is also important to remember that transient synovitis is a diagnosis of exclusion, and it is important to rule out other causes of hip pain that may require urgent intervention, such as septic arthritis.

Question 24

A 3-year-old female is at the pediatrician’s office for continued right knee pain after a ground-level fall six weeks ago. The patient is UTD on all immunizations, has no significant PMH, and no recent illnesses. Mom reports the patient complains of pain mostly in the morning when going to daycare but doesn’t seem to be bothered by it while playing outside in the afternoon. On exam the patient’s vitals are all within normal limits. Her physical exam reveals a well-appearing toddler who walks stiffly and avoids bending her right knee. The knee has a mild effusion but no obvious erythema. There is pain with passive flexion and extension of the right knee. During the exam the girl tells you her left ankle also hurts, which mom had forgotten about but says started hurting the same time as the right knee. Her CBC is normal, while her ESR and CRP are mildly elevated. Which of the following is the most likely cause of this patient’s condition?

 Single Choice Answer:
Please select one answer.  
A		Septic arthritis	
B		Leukemia	
C		Juvenile idiopathic arthritis	
D		Transient synovitis of the hip	
E		Bacterial osteomyelitis

Answer 24

C

effusion of knee ==> seen in septic arthritis/ transient synovitis
pain with passive ROM of knee and ankle

JIA

Pauciarticular juvenile arthritis is the most common type of JIA (60% of JIA) and causes pain in four or fewer joints for six or more weeks. This patient is generally well even after six weeks of pain, which would be unlikely if this patient had septic arthritis. Her pain improves with activity, and the ESR/CRP are only mildly elevated. On exam, she has a mild effusion but no obvious erythema. In cases of systemic JIA, patients may have a rash which lasts only a few hours (evanescent) that is also macular and salmon, and high-spiking and appears periodically (once or twice a day); however, this form of JIA is not consistent with this patient’s history.

while acute, generally resolves in three to four days and this patient has had pain for six weeks. Transient synovitis typically affects the hip, but patients may also report knee or inner thigh pain. Commonly, patients may have a history of a recent URI. Additionally, patients with transient synovitis do not typically present with a joint effusion as is seen in this patient.

Question 25

A 4-year-old child is refusing to walk over the course of a week. Her mother recalls that she fell off her bike yesterday. On exam, she is afebrile, but has decreased ROM of her hip. You review her file and note that she is up-to-date on her immunizations and she was last seen three weeks ago for a self-limited episode of diarrhea that she developed while visiting family in rural Mexico. Aspiration of her affected hip joint reveals slight increase in inflammatory cells but normal chemistries and a negative gram stain. Culture is pending. Which of the following is the most likely diagnosis?

 Single Choice Answer:
Please select one answer.  
A		Osteomyelitis	
B		Trauma	
C		Transient synovitis	
D		Reactive arthritis	
E		Septic arthritis

Answer 25

D

decreased ROM
post-GI problem

no sepsis

increased inflammatory cells in aspirate

The patient likely had a recent case of mild to moderate gastroenteritis in Mexico, which may have been secondary to an bacterial enteritis such as shigella, or campylobacter. In reactive arthritis, joint inflammation occurs a few weeks later because antibodies made during the illness are attacking the joint. While several inflammatory cells would be seen in the aspirate, importantly, the cultures will turn out to be negative.