Lower Extremity Problems in Children
Part 2
AAP Board Content Specifications:
 Know that Legg-Calve Perthes disease commonly occurs between 3 and 10
years of age
 Know that boys are more likely to have Legg-Calve-Perthes disease than girls
 Know that Legg-Calve Perthes disease should be considered in the
differential diagnosis of a child with limp
 Know the presenting symptoms of a slipped capital femoral epiphysis & plan
appropriate management
 Understand the significance of toe-walking in patients at various ages
PREP Board Questions:
1. A 5 y/o previously healthy male has developed a limp and right hip pain over
the past week. There is no history of trauma, fever, rashes, or other systemic
symptoms. On physical examination, he has limited internal rotation and
abduction of his right hip; other findings are wnl. A lateral, AP, and frog leg
radiograph series demonstrate a crescentic subchondral lucency in the
medial aspect of the epiphysis (see pic below). Of the following, the MOST
likely diagnosis is:
a. Developmental hip dysplasia
b. Legg-Calve Perthes disease
c. Septic hip
d. Slipped capital femoral epiphysis
e. Toxic synovitis of the hip
2. You are examining a healthy 4 y/o boy who has complained of intermittent
left anterior thigh pain over the last 1-2 months. In the past week, the
parents have begun to notice that his is limping slightly on that side. He has
had not fever, malaise, other complaints of pain, or change in appetite or
activity. He is taking no medications. Physical examination reveals an
afebrile child who has no redness, warmth, or swelling over this legs or feet
1
and no point tenderness over his spine, pelvis, thigh, lower leg, feet, or
abdomen. He does exhibit decreased internal rotation of the left hip. His
peripheral white blood cell count is 9.6x103/mcl, ESR is 8 mm/hr, CRP is 0.4
mg/dL. Radiograph evaluation shows flattening & sclerosis of the femoral
head on the left (see pic below). Of the following, the MOST appropriate
management includes:
a. Observation at home & follow-up in 1 week
b. Ortho consult
c. Parental antibiotics for 2-4 weeks
d. Physical therapy referral
e. Rheumatology consultation
3. A 13 y/o boy has complained of dull medial thigh pain for a month, but his
parents have only noticed a mild limp for the last 3 days. He has had no
trauma, fever, rash, weight loss, or fatigue. His BMI is at the 95th percentile
for his age and he is at sexual maturity rating 3. There is mild tenderness
over the thigh. The knee is not red or swollen, and there is no ligamentous
laxity. Physical examination of his hip shows mildly limited abduction with
decreased internal rotation. Of the following, the MOST appropriate
diagnostic test for this boy is:
a. AP & frog leg radiographs of the hip
b. Bone scan of the hip
c. MRI of the knee & thigh
d. Serum CK, CBC, and CRP levels
e. Ultrasound of the hip
PIR Questions:
4. A mother brings in her 3 y/o son because she thinks he “walks funny.” On
physical examination, you note that he consistently walks on his toes. Other
findings, including those on neurologic exam, are normal. Which of the
following statements about this boy’s condition is true?
a. Bracing the feet & lower legs should be initiated immediately
b. He should be tested for muscular dystrophy
c. He likely will not perform well in sports
d. Heel cord contracture will likely develop if toe walking continues
e. There is a high probability that he has an underlying spinal cord
disorder
2
Hip disorders:
These disorders typically present with limp +/- pain, not always located in the hip
 Legg Calvé Perthes Disease (LCP):
o Definition: Idiopathic avascular necrosis of the femoral head
o Causes: unknown, thought to be multifactorial
o Prevalence: 0.2-29/100,000 in children <14 y/o
o Epi:
 Typical age 3-10 y/o, peak 5-7 y/o
 4:1 Male predominance
 Bilateral is less common- 10-20%
 If present should undergo evaluation for
heminglobinopathy or skeletal dysplasia
 African Americans rarely affected
 Risk factors: renal failure, steroid use, lupus, HIV, familial
(10%)
o Clinical presentation:
 Insidious onset of limp & may have pain
 Pain is localized to knee or thigh > buttocks, rather than hip
 Pain worse with weight bearing & ambulation
 Trendelenburg gait
o Examination: similar to SCFE
 Limited abduction & internal rotation of the hip
 Findings most prominent at extremes of the range of motion
o Imaging:
 Radiographs: AP & frog leg (may be normal)
 Sclerosis, flattening, and fragmentation of femoral head
 Progression of 4 phases:
1) Narrowing & sclerosis of the femoral epiphysis
2) Fragmentation of the femoral head (crescent
sign)
3) Reossification
4) Healing
 Crescent sign: subchondral linear lucency representing
fracture through necrotic bone (best seen on frog leg
view)
3
 MRI: more sensitive in detecting early disease
o Differential:
 SCFE (see below)
 Coxa Vera: defect in ossification of femoral neck leading to a
decreased femoral neck shaft angle
 Patients aged 2-6 y/o with limp or waddeling gait +/leg length discrepancy
 Exam: decreased abduction & internal rotation
 Imaging (AP & frog leg): Decreased femoral neck angle <
130 degrees
 Prognosis: can lead to osteoarthritis, usually
spontaneous correction with growth but some require
surgery
 Coxa Valgus: defect in ossification of femoral neck leading to an
increased femoral neck shaft angle
 Patients are typically asymptomatic
 Generally associated with DDH or spasticity of
adductors, but can be congenital
 Exam: increased adduction & internal rotation
 Imaging (AP & frog leg): Increased femoral neck angle >
135 degrees
 Prognosis: can lead to osteoarthritis, usually
spontaneous correction with growth but some require
surgery
 Infection: septic arthritis, osteoarthritis, myositis
 Inflammatory: transient synovitis, SLE, JIA
 Trauma
o Prognosis:
 Runs its course of ~2 yrs
 Best prognosis in children <6 y/o at presentation or there is
less than 50% necrosis of the femoral head.
o Treatment: Ortho Consult, but treatment is poorly defined
 Physical therapy
 Bracing
 Surgery
 Slipped Capital Femroal Epiphysis (SCFE):
o Definition: displacement of the femoral head in relation to the
femoral neck through the growth plate during rapid growth of
adolescence
o Incidence: 1/1,000- 1/10,000
o Epi/risk factors:
 Males: Females = 1.5:1
 Age of onset: adolescence
 Females: 10-14 y/o (before menarche)= mean is 12
 Males: 11-16 y/o (before tanner 4)= mean is 13.5
4
African Americans & Polynesians at increased risk
Obese (up to 1/3 or patients are not obese)- 60-65% of those
affected are above the 90th percentile for weight for age
 Bilateral in 20-40% of the cases (one side can be
asymptomatic)
 Risk Factors: Renal failure, radiation therapy, endocrine
disorders (hypothyroid & growth hormone > other disorders),
Genetic disorders (Down syndrome)
Clinical presentation:
 Insidious pain or limp, but onset can be acute
 Pain is described as non-radiating, dull, aching
 Lack of preceding trauma
 Pain localized to groin in < 50% of patients
 Most complain of knee or thigh
 Pain worse with physical activity & improves after
sitting (can be 1+ hrs later)
Physical Exam: Ensure exam of hip, knee, and foot
 Limp with ambulation
 Gaits may vary depending on severity/distribution:
 Trendelenburg (moderate to severe)
 Antalgic (unilateral)
 Waddeling (bilateral)
 External rotation of the foot on affected side
 External rotation & abduction of thigh that accompanies hip
flexion is highly suggestive of SCFE
 Internal rotation, abduction, and flexion of the hip is limited or
painful
 Most common physical exam findings: decreased internal
rotation, abduction, and flexion (<90 degrees) on passive
movement, trendelenburg gait
4 patterns of presentation:
 Pre-slip- pain without displacement. X-ray shows widening of
proximal femoral physis
 Acute (10-15%): sx < 3 weeks, joint effusion but no
metaphyseal remodeling, usually associated with trauma
 Severe pain, external rotational deformity, limited ROM,
shortening of leg length, inability to bear weight
 Acute on chronic: hx of sx & signs of chronic SCFE (>3 weeks
of pain or limp) with acute increase in pain & loss of ROM of
affected hip.
 Joint effusion & metaphyseal remodeling is present
 Chronic (most common): vague, intermittent sx over
protracted period (>3 weeks) without joint effusion, but
metaphyseal remodeling is occurring
Diagnosis & Management:


o
o
o
o
5



If < 10 y/o or ≤10th percentile for Ht should undergo endocrine
evaluation
 TSH, Free T4, bone age
Consider atypical causes: renal failure
Radiograph: AP, lateral (frog leg or cross table) views of both
sides
 AP view: mild widening, lucency, or irregularity of the
physis. Blurring of the junction between the metaphysis
& growth plate
o Blanch sign of steel- posterior slippage of femoral
head  the portion posterior to metaphysis may
be projected as a semicircular area of increased
density on the proximal part of femoral neck
o Klein line: line drawn along superior femoral
neck intersects the lateral portion of femoral
head

Lateral view: necessary to make diagnosis in 10-15%.
Posterior displacement & step off of the epiphysis on
the femoral neck. If having acute sx recommend cross
table not frog leg (can displace further with frog leg)
6
MRI: if x-ray is normal but still suspected. Able to detect early,
radiologically occult but symptomatic pre-slips
o Prognosis:
 30-60% of patients present with slip on contralateral side
within 1 yr. Increases to 100% if has underlying endocrine
disorder
 Prognosis depends on severity of slip

Complications:
 Osteonecrosis of femoral head (aseptic
necrosis/avascular necrosis)- occurs in 15% of acute
slips, complication of surgery
 Chondrolysis- narrowing of the joint space & loss of
articular cartilage occurs in 7%. Leads to pain, flexion
deformity, restricted ROM
 Osteoarthritis- premature development, incidence
depends on severity of slip
o Treatment: Referral promptly to Ortho
 Surgical: placement of metal screw across growth plate to
prevent further slip
 Developmental dysplasia of the Hip (See DDH handouts)

7
Toe walking
 May occur as a normal phase in gait development.
 Toe-walking beyond 3-4 y/o is considered abnormal
 Etiology:
o Cerebral Palsy
o Tethered spinal cord
o Muscular dystrophy
o Intraspinal lesion or tumor
o Acute myopathy
o Ideopathic- persistence beyond 3 y/o
o Tight heel cords
 Diagnosis:
o Ideopathic- no findings on physical exam, easily dorsiflexed, no LE
spasticity or hyperreflexia, only seen when walking.
 With time can develop heel cord contracture & calf
hypertrophy
 Long term can develop external tibial torsion, splaying of
forefoot
 Can differentiate from CP because can walk on heels whereas
CP patients usually can not
o Complete neurological examination -> workup depending on exam
 Treatment:
o Referral to Orthopedist around 3-4 y/o
o Physical Therapy- stretch out achillies tendon
o Ankle-foot orthosses
o Serial casting- if fails stretching
o Botulism toxin- useful as adjunct to serial casting
o Surgical lengthening with bracing- when all other treatments have
failed
Board Answers:
1. PREP 2011, #19: B
2. PREP 2011, #35: B
3. PREP 2013, #103: A
4. PIR 2009 (Lower extremity disorders in Children & Adolescents): D
References:
1. Kinestra, AJ, Macias CG. Slipped capital femoral epiphysis (SCFE). In:
UpToDate, Phillips, W (ed), UpToDate, Waltham, MA, 2012.
2. Nigrovic, PA. Overview of hip pain in children. In: UpToDate, Drutz, JE (ed),
UpToDate, Waltham, MA, 2013.
3. Scherl, SA. Common Lower Extremity Problems in Children. Pediatrics in
Review. 2004; 25 (2): 52-62.
4. Smith, BG. Lower Extremity Disorders in Children and Adolescents.
Pediatrics in Review. 2009: 30 (8): 287-294
8